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The Brain in Love: Has Neuroscience Stolen the Secret of Love?



No one knows when the story of love began in the history of mankind, though from a religious point of view it started with Adam and Eve and the Forbidden Fruit. Scientifically speaking, love probably made its appearance with H. neanderthalensis between 350 and 30 thousand years ago. Neanderthal graves have yielded the pollen of brightly coloured flowers brought from different regions, and these have been associated with some kind of loving relationship between the living and the dead. If love started with the Neanderthals, anthropological studies have shown that today, 147 out of 166 societies in the world have a word for love or at least the concept of love, while for the other nineteen, it has been suggested that not enough questions of the right kind have been asked to discover whether it exists or not. For this reason, love is accepted as a universal or near-universal feeling.
The Brain in Love: Has Neuroscience Stolen
the Secret of Love?
Sultan Tarlacı, MD
No one knows when the story of love began in the history of mankind, though from a
religious point of view it started with Adam and Eve and the Forbidden Fruit. Scientifically
speaking, love probably made its appearance with H. neanderthalensis between 350 and 30
thousand years ago. Neanderthal graves have yielded the pollen of brightly coloured flowers
brought from different regions, and these have been associated with some kind of loving
relationship between the living and the dead. If love started with the Neanderthals,
anthropological studies have shown that today, 147 out of 166 societies in the world have a
word for love or at least the concept of love, while for the other nineteen, it has been
suggested that not enough questions of the right kind have been asked to discover whether it
exists or not. For this reason, love is accepted as a universal or near-universal feeling.
Why Do We Feel Love?
You would get different answers to this question from psychiatrists, theologians and
evolutionary biologists. If you asked a psychiatrist, you would be told that from the
viewpoint of psychoanalysis, love is the external expression of an oedipally suppressed feeling
and a precious flower which the super ego has raised up to the skies. According to Oedipal
suppression, boys are in love with their mothers and girls with their fathers, and at around
the age of six this is suppressed. Later, when they meet a member of the opposite sex with
similar characteristics to the parent, passionate love occurs. According to theologians,
human love is a small reflection of divine love. It is a small attempt to attain that great love,
one of the small steps on the ascent to divine love. There is a beautiful story concerning this:
a man took his son from Anatolia to a religious teacher in Baghdad, and said to him, “Make
this boy your student, and let him learn the way of God.” The sheikh said to the boy, “Are you
in love with anyone?” When the boy answered “Yes, I love a girl back in the village,” the
sheikh said, “My child, we can do nothing for a person who already has someone in their
heart.” And to the father he said, “Take him home and let him get married.” The man
returned to his village and this time took his younger son to the sheikh in Baghdad. The
teacher asked, “My child, have you ever been in love?” “No, sir,” said the boy. At this the
sheikh turned to the father and said, “Take this one home too, and bring him back after he
has been in love.”
The loves of Joseph and Mevlana are passionate expressions of Divine Love. In folk
tales, the loves of Leila and Majnun, Kerem and Aslı, Farhad and Shirin, and Tahir and Zuhre
are small human steps in that direction.
Why do People Fall in Love with a Particular Type?
There is no certain answer to this question, only a number of approaches and findings.
The first steps in the process happen in 30% of people when they encounter a face which
appears to have good symmetry. What actually starts it is not so much beauty, but along with
it such important indicative factors which will add to the richness of the person’s own life as
intelligence, trustworthiness, kindness, and charm. The factors which determine falling in
love are formed in particular under the effects of the testosterone levels to which we are
exposed in the 8-16th weeks of pregnancy, the attention which is paid to us in childhood, and
adolescent hormones. Again, love may start as a great surprise when the opposite person
shows liking. The desire for small contacts may make this more apparent.
But what concerns us most here is not what type or person we fall in love with, but
rather the question of what happens in our brain when we fall in love. In neuroscientific
terms, the question is whether love has a neurobiological or chemical equivalent, and
whether there is a romantic system or neural circuit in the brain.
What Happens in the Brain in Love?
In neuroscience, love is much stronger than a basic emotion or state of mind.
Emotionally, it means thinking obsessively and repeatedly about the beloved. This takes up
around 85% of waking time. The person’s own priorities change and there is a continual,
compulsive desire for closeness. Anxiety and fear are reduced, and risk-taking is made
easier. A feeling of ecstatic, euphoric happiness takes over the person, and he or she is ready
to die for the beloved. All the possessions of the beloved are seen as extensions of
him/herself and even a simple piece of trash from the beloved is imbued with a kind of sacred
quality. At the same time love has deep physiological effects on the body. Among these are a
reduction in appetite and a loss of interest in food-drink, and pain sensitivity, an increase in
the pulse rate, palpitations, sweating, trembling, intestinal activity, and an increase in
stomach acidity and the rate of swallowing. Over the ages, these physiological responses have
made people think that the heart was the instrument of falling in love. However, a feeling
with so many emotional and physiological effects would surely be expected to be reflected in
the brain.
In order to understand whether there is a system in the brain for taste, sight, smell,
touch, hearing, or at a more complex level violin playing for example, the most-used method
is functional MR (fMRG) brain imaging. This is a method which can show which regions of
the brain operate in response to a particular stimulus or for a specific purpose. The basic
principle is simple: changes in blood flow (haemodynamic response) and oxygen (blood-
oxygen-level-dependent – BOLD) take place in certain parts of the brain in connection with
operations which the brain is performing. Differently functioning brain regions can be
shown by fMRG by comparing them with the brains of normal people, i.e. individuals who
are not performing those operations.
In 2003, Semir Zeki and his colleagues, who had spent years investigating the
organisation in the brain cortex of the human visual system, published the first study on the
question of what happens in the brain of a person who sees a photograph of someone whom
they love, and the findings provoked a large response. Eighteen people who were
passionately in love were included in the study, and their brain activity was investigated by
fMRG when they were shown a picture of the person they loved. When they first saw it, their
brain’s subcortical reward system showed great activity. Among these regions, activity in the
caudate head, putamen, insular cortex, hippocampus, anterior cingulate cortex cerebellum
and ventral tegmental area was noticeable. The results were a surprise to everyone. Certain
brain regions, especially those which gave rewards, were responding to the events. A reward
obtained will certainly cause a repetition of the activity which produced the reward. This
includes food, water, sex, cigarettes, cocaine and positive social interactions, and the result is
subjective satisfaction. When the reward cells are eventually satiated with the stimulus, they
enter a quiet state. Repeated activity slowly comes to an end.
What then are the deeper functions of these parts of the brain which spring into action
when the lover sees the beloved? The most remarkable of these regions is the A10 region in
the ventral tegmental area (VTA). The VTA, along with the substantiva nigra, is the source of
90% of the dopamine in the brain. Because of this region’s richness in dopamine, it is active
in all reward stimuli. In addition, it contributes to wakefulness, attention, increased libido,
motivation and reward-seeking. The basic function of dopamine is the “want” in the reward
system. At the same time, dopamine is closely associated with novelty-seeking and creativity.
It is the source of reiterative thought and behaviour. The clinically pathological state of this
can be seen in schizophrenic and Parkinson’s patients during excessive dopaminergic
stimulation in dopamine dysregulation syndrome. At the same time dopamine creates the
feeling of unity with the beloved. It is dopamine which causes poets to write poetry when
they are in love, and musicians to make music. The pallidum and the caudal nucleus
integrate sensory input with motor output in order to bring it into action. This provides the
detection of reward and purposeful behaviour. The anterior cingulate cortex evaluates
internal and external stimuli, and creates suitable emotional responses to them. It provides
decision-making, risk analysis and self-awareness. The hypothalamus, as is known from
previous studies, deals with both sexual stimuli and loving stimuli. The autonomic system is
the central producer of various sexual hormones. It also regulates hunger, thirst and body
temperature. The insular cortex creates that feeling of restlessness when we are in love, and
reflects our emotions on to our bodies in the form of a rise in the pulse rate and sweating.
Figure. Brain regions showing activity in people madly in love
In brief, when people in love see their beloved, they fall into an ocean of dopamine in
the reward pathways in their subcortical structures. So then what happens in the brain
cortex? According to the results of the same fMRG studies, there is a deactivation in various
cortical areas in contrast to the subcortical active regions in the brain cortex of people who
are in love. Regions which show de-activation or reduced activity are the prefrontal region,
the parieto-temporo-occipital region, and the temporo-parietal region. The prefrontal
region in humans is the most important region for visualisation, intention and decision-
making, and logical deduction. It is the source of logic and adherence to social rules, morality
and respect. The reduction in the activity of this region in people in love results in a
weakening or loss of its functions. This is at the base of the stories of films like Aşk-ı Memnu
(Forbidden Love), in which Behlül falls in love with his uncle’s wife Bihter, giving the film its
name. This is possible because the brain regions responsible for logic and the rules of social
morality have stopped working properly. Another example is the story of the fall of Troy, in
which Paris, the young prince of Troy, is a guest of Menelaos, king of Sparta in Greece, and
falls in love with the king’s wife Helen. He carries her away to Troy, with the result that
Menelaos and his brother Agamemnon lay siege to the city. And the rest is history, or at least
legend: the wooden horse and the destruction of Troy. When you’re in love, the rules of logic
aren’t applied. Love comes in, and sense goes out the window. It is for this reason that
people in love tend to take stupid and illogical risks. In the case of an impossible love, they
are not persuaded by people trying to make them see sense. The parieto-temporo-
occipital region provides a person’s sense of position in space, and spatially separates the
self from the other. When this region is deactivated, the separation between self and other is
suspended, and the person experiences “unity” with the beloved. In this way, just as a person
cannot conceal the fact that he is drunk, he or she cannot conceal the fact of being in love.
The Difference between Men and Women
Is there a difference between the active brain regions of men and women when they are
in love? To answer this question, seven men and ten women who were in love were examined
by fMRG, and different areas were assessed. In men, greater activity was seen in the right
dorsal insula, associated with penile tumescence, the region for seeing beautiful faces, and
the visual integration area. In women, the regions for attention, memory and emotion
showed greater activity. From this we can understand that men fall in love with women and
their faces in a way that includes sexual arousal, while women are more interested in the
romantic aspect of love – that is, they fall in love with love itself!
The Love of a Mother for her Child and the Love of a Lover for the Beloved
To investigate this, fMRG studies were carried out comparing mothers and lovers. The
mothers were shown pictures of their child, while the lovers viewed pictures of the face of
their beloved. When the fMRG images of the mothers and the lovers were superimposed, just
about the same regions of the brain showed activity in the two groups, except for one. These
areas were the anterior cingulate cortex, the caudate nucleus, the bilateral insular region, the
striatum (formed from the putamen + caudate nucleus and the globus pallidus), the
GENİŞLET---PAGC, and the hippocampus. The only difference in mothers looking at their
children was that increased activity was seen in the PAGC. The PAGC has been confirmed in
many other studies as specific to mother’s love, and this region was not active in lovers. Why
the PAGC? This region is in particular a region where the endogen reduction and pain
relieving mechanisms and the encephalinergic system are concentrated. The secretion of
endorphin and dinorphins blocks mu receptors and the secretion of Substans P, which is a
transmitter in the pain pathways behind the spinal cord. Stimulation of this region provides
substantial analgesia and is probably one of the regions providing analgesia during birth.
While this is happening in the deep brain structures of mothers, is anything happening
in the brain cortex which is different from lovers? In mothers, deactivation is seen in the
parieto-temporo-occipital, prefrontal region and the medial temporal region. These are the
same regions as the deactivated cortical regions seen in lovers. This means that mothers
have the same problems of visualisation, intention and decision-making and logical
deductions as lovers. Also, as with lovers, there is no distinction between “self” (the mother)
and “other” (the child).
Is Love a Morbid Obsession?
Everyone accepts that up to a point love is an obsessive condition. The lover constantly
thinks about the beloved. In the case of head-over-heels love, this may occupy about 85% of
waking time. The desire to see and touch the beloved is constantly repeated in their
thoughts. Obsession is known as a compulsive, involuntary, compelling cyclical thought
pattern. The person is aware of it, but cannot stop thinking these thoughts. This can lead to
distress. In order to relieve this stress, ritual-type compulsive behaviour may develop. In
obsessive disorders, a reduction has been shown of 5-HIAA, a breakdown product of
serotonin, in the spinal fluid and blood. At the same time, obsessive disorders show a good
response to drugs which stimulate the serotonergic system. In other words, there is a
consistent relationship between the serotonergic system and obsessive disorders.
Concentration of PLT-Serotonin Transporter in Serum
Normal n = 20
OCD n = 20 DSM??
20 lovers – 6th month
6 lovers – 12-18th month
Differences in serum ST concentration between normal people, those diagnosed with
obsessive-compulsive disorder, and people in the 6th and 12-18th months of being in love.
Levels are lower than normal in the 6th month of being in love, but this gradually returns to
Could the early stages of being in love be a similar condition to obsession? In searching
for an answer to this question, measurements were made of the concentrations of serum
thrombocyte serotonin transporter (PLT-ST) in 20 normal people, 20 people who had been
newly diagnosed according to DSM with obsessive disorder but who had not taken any
medication, and 20 people who were in the 6th month of being deeply in love. As expected,
PLT-ST concentrations of people with obsessive disorder were found to be considerably
higher than those of normal people (1328 as against 736 fmmol/mg protein). What was
interesting was that the value for the people who were in love was even lower than that of the
obsessives (624 fmmol/mg protein). The researchers wondered how PLT-ST levels in the
lovers would change over time; they measured the values of six of the lovers in the 12-18th
month when they were still (but no longer passionately) in love, and found that values were
no different from normal (1241 fmmol/mg protein). From this it can be seen that in the
period of passionate, head-over-heels love, there is a change in PLT-ST levels consistent with
obsessive disorder. Passionate love is an obsession, and from the point of view of serotonin
chemistry it lasts around 12-18 months.
Love’s Traditional Home – the Heart
Love has traditionally been associated with the heart, and even today we draw a heart
to represent love. The reason for this is the rising central (in the brain) and peripheral level
of nor-epinephrine (NE). In the periphery, the increase in NE causes tachycardia,
palpitations, a rise in blood pressure and trembling hands in the presence of the beloved.
With this exaggerated stimulus effect on the heart, love is perceived as centred not in the
brain but in the heart. This increase in the central nervous system affects the locus ceruleus,
and causes an increase in attention and in focus on the beloved. This focussing and attention
means that small details about love are remembered. At the same time it causes sleepless
nights and a loss of appetite. NE also causes an increase in sexual motivation. Amphetamine
given at a suitable dose will potentialize all of these effects on dopamine and NE in the same
The Puzzle of Testosterone
In the period of passionate and intense love there is also a change in the sex hormones.
These hormones have receptors in the brain. The change in testosterone is one of the most
interesting of these changes. In this early period, testosterone levels fall in men but rise in
women, a finding which is in conflict with the expectation that it would rise in men.
However, the reason why it should fall in men and rise in women can be found logically.
First, a reduction in testosterone in men softens their masculine characteristics and reduces
their extroversion. It makes it easier to concentrate on one person. At the same time it
causes a reduction in masculine aggressiveness, and this softening is reciprocated by the
woman. With regard to the increase in testosterone levels in women, there are a number of
logical explanations. In the novelty of love there is a risk arising from uncertainty. The rise
in testosterone in women makes it easier to take on that risk. During ovulation, a rise in
testosterone increases sexual desire in women. At the same time it increases a woman’s
extroversion and awakens her masculine attributes. As a result, just as love begins, the
changes in men’s and women’s testosterone levels bring the two sexes closer together, if only
for a short time.
Does Love Rejuvenate the Brain?
Swimming in an ocean of dopamine in the period of being passionately in love is a
principal source of creativity for poets and musicians. The main neurotrophic factor which
keeps the brain young is neuron growth factor (NGF). To find out whether there is a change
in neurotrophin levels in people who are passionately in love, serum levels of NGF, BDNF
and neurotrophin 3-4 were measured in 58 people who were in the first six months of being
passionately in love and who thought about their beloved for at least four hours a day. Serum
levels were compared between people who were not in love and those who had been in love
for a short time (the first six months) and for a long time (49 months). Serum NGF levels in
the newly passionate lovers were found to be significantly higher than those of people who
were alone and not in love (277 as against 149 pg/mL) – almost double. NGF levels in the
long-term lovers were found to have fallen to 45% of that of the passionate lovers in their first
six months, and were even below that of normal people (143 as against 149 pg/mL). At the
same time, a significant relationship was detected between the scores of these people on the
Passionate Love Scale and their NGF levels. As their scores for passionate love increased, so
did their NGF levels. No similar change was measured in other neurotrophic factors.
Serum NGF level pg/mL
45% reduction, p<0.001
58 Lovers
First Six Months and 49 Months
Thinking at least 4 hours
Alone - Normal
Lovers - First Six Months
Long-term love (49 months)
Figure. Compared with normal people, the NGF serum levels of people in
the first six months of passionate love are considerably raised, while as time
goes on these levels even fall to below normal.
So what is the advantage of this increase in NGF in the period of passionate love? NGF
is essential for the life of neurons and dendritic growth. This is true both for the peripheral
and the central nervous systems. It increases their myelinisation, speeds up healing and has
aniogenic properties. Along with this, it increases opioid sensitivity and the secretion of
cortisone and vasopressin. A fall has been associated with various pathological conditions
such as neural degeneration, dementia, depression, autism, and an increase in sensitivity to
Does Love Soothe Physical Pain?
One of the reasons why love causes bonding is the increase in encephalins, which
pervade the concept of love. There are morphinergic and encephalinergic pathways in the
reward-pleasure system. In particular, stimulation of the mu3 receptors causes a feeling of
wellbeing. It erases negative memories, and strengthens positive and happy states in the
memory. With this strengthening of good memories, the lover selectively only remembers
the good things, so that he or she is prevented from seeing the true “whole picture” of the
beloved. Everything is viewed through rose-tinted spectacles. And at the same time the
morphinergic system can perform its expected role of non-pharmacologically reducing
sensitivity to pain.
But does love really reduce sensitivity to pain? In one study, 15 people in the first nine
months of being in love were subjected to severe and slight thermal pain in the hand. When
they were shown a picture of their beloved, pain scores for the severe pain fell from 7.2 to 6.2,
and the score for slight pain fell from 3.7 to 2.4. That is, the scores on the visual pain scale
for both severe and slight pain fell by about one point.
Another study examined the effect of holding the beloved’s hand and seeing his or her
picture with thermal pain as a stimulus. Twenty-eight women in the first six months of being
passionately in love were included in the study. When they held their beloved’s hand, their
pain scores were measured as about 0.5 points lower, but when they held the hand of a
stranger, it was found that their score rose by up to 1.5 points. A similar result was obtained
when the subjects were shown a picture of their beloved: their pain score fell by about one
point. When they looked at the picture of a stranger’s face or of an object, their pain score
showed a very slight increase. That is, holding the hand of the beloved or seeing a
photograph of them reduced their pain score, or in other words it caused them to feel less
GAS: Visual Pain Score??
Maşuk: Beloved
Yabancı: Stranger
Obje: Object
Holding hands
Viewing photograph
Figure: A reduction in pain scores is caused in lovers by holding the hand or seeing a
photograph of the beloved compared with that of a stranger.
How can love reduce pain?
As we saw before, the morphinergic-encephalinergic system, which comes into
operation in love, is an anti-nociceptive painkilling and pain reduction system. With NGF
increasing at the same time, it strengthens the painkilling encephalinergic system. In
addition, in fMRG studies of the brain, a reduction in activity has been shown in the ventro-
lateral nucleus of the thalamus and the supplementary motor area. The ventro-lateral
nucleus of the thalamus is the place through which pain is carried to the brain cortex. A
reduction in the working of this nucleus weakens the direct transmission and interpretation
of pain to the brain cortex. Also, the supplementary motor area is a region whose activity is
seen to be reduced and which is important in pain integration. At the same time, the reward
and pleasure system are directly activated and bring the reductive pain system into
operation. Pain sensitivity is reduced through both systems. We saw that when mothers see
pictures of their children, it is especially activated. This region is the most important place in
the reductive painkilling system. When the love poet Cemal Süreya says “I have imprisoned
you in my fingertips. I feel you in every place that I touch, and my soul is burning”, we must
welcome it, because love only gives one point of non-pharmacological benefit on the visual
pain scale!
When we think that love and the support of the beloved can reduce pain, lovers being
together when they are in pain, or at least being able to see a photograph, can help as a non-
pharmacological pain reliever. On the other hand, it makes it easy to understand why those
unhappy in love constantly complain of headaches, backaches, and other aches and pains.
The Case of Unrequited Love
In the game of love, we often come across lovers who are rejected. Each rejection
provokes a protest in the lover, and then follows an obsessive desire to regain the beloved.
This is because the source of reward and pleasure is about to be lost. However, after a time, if
this attempt is unsuccessful, acceptance of the loss begins to take effect. In this period, we
often see hopelessness, anger, irritability, and social isolation. Signs of depression are seen in
40% of rejected lovers, and in 12% it results in medium to serious depression. At this time,
aggression, suicide and murder also occur.
What is happening in the brains of these rejected lovers? An fMRG study was
performed on 15 rejected lovers who still spent 85% of their waking time thinking about their
beloved (we are not including in this what may have gone on in their dreams!), and the same
active brain areas were seen as in those passionately in love. Even when they were rejected,
their brains showed the same areas of activity as in people totally in love. What was different
from happy lovers was greater activity in the right accumbens nucleus and the ventral
pallidum. This same increase in activity in the right accumbens nucleus seen in people who
have lost someone close to them. That is, rejection in love provokes a similar reaction in the
brain to death and bereavement. Also, the ventral pallidum is a region which is rich in
vasopressin (VZP – Wikipedia’ya göre, İngilizcede genelde AVP oluyor: Arginine Vasopressin.
Seçenek sizin – ben değiştirmedim. ) 1A receptors. We will come back later to the
importance of this region and its connection to VZP. Activity in this region declines as love
continues and disappointments in love increase. Activity begins in the left insular cortex, an
area which also shows activity in times of anxiety, weeping, and when pain is inflicted on the
skin. Finally we arrive at the situation which Peyami Safa compared with death: “... (burasını
tam olarak anlamadım) This is the most right, the most innocent, the most potent and the
most magnificent murder...”
Fidelity, Cheating and Monogamy/Polygamy
If there is deep and passionate love and fidelity, how is it that we also see infidelity and
cheating? In mammals there are two hormones which control fidelity: oxytocin (OXY) and
vasopressin (VZP). VZP is also called arginine-VZP and the antidiuretic hormone. OXY and
VZP are synthesised in the hypothalamic magnocellular supra-optic and paraventricular
nuclei and released into the blood by axonal transport from the pituitary gland. These are the
only hormones which are released from the pituitary gland and have a direct distant effect on
the body. The two hormones have a similar structure, and partially affect each others’
receptors. In humans, they are both coded on the same chromosome, 20p13, while the
receptors are coded on chromosome 2. They have a peptide structure formed from nine
amino-acids, and differences in the third and eighth amino-acids make the difference
between them. The hormone OXY is structured Cys-Thr-Ile-Gln-Asn-Cys-Pro-Leu-Gly-NH3,
while VZP has the structure Cys-Thr-Phe-Gln-Asn-Cys-Pro-Arg-Gly-NH3. These hormones
are also found in worms, rodents, birds, octopuses, elephants and whales, with variations in
amino-acids in the same areas causing inter-specific differences. They have peripheral
classical effects: OXY causes milk production and contractions of the uterus during birth,
while VZP is involved in water retention (especially on VZP-2 receptors).
Along with their peripheral effects, OXY and VZP have receptors which give them a
greater effect on the central nervous system, in many regions from the brain stem to the
spinal cord. OXY receptors are found in the accumbens nucleus, the amygdala and the
hippocampus. OXY is involved in the formation of social memory, the recognition of facial
emotion, and the feeling of trust in other people, and causes aggression in pregnant women
and mothers. It is fundamental to male-female pair-bonding, mother-child bonding... It
passes from breast-feeding mothers to their children and increases mother-child bonding.
When the OXY gene does not function, problems are experienced in memory of social events
and recognition. The social memory is disrupted. When the OXY receptor is blocked in
mothers, care for the infant decreases. Secretion of OXY from the rear pituitary rises in
parallel with oestrogen in the blood. It rises appreciably in embracing and suckling, and
during birth, sexual arousal and orgasm. OXY has been called the cuddling chemical. It is
prominent in bonding in women, while VZP is more closely related to bonding in men.
VZP, especially in men’s brains, mostly has VZP1A receptors in the ventral pallidum
and putamen region. In men it has functions such as the formation of pair bonding,
aggression, territorial defence, protection of children and hierarchical organisation. The
effects of OXY and VZP overlap to some extent in both men and women.
What We Learn from Rodents
How can monogamy and polygamy be explained? In nature, only 3-5% of all species
(bu doğru değil: memeli hayvanların %3-5’i, kuşların %90’u monogamik oluyormuş.
Albatros bir kuştur.) – albatrosses and voles for example – are monogamous, that is they only
have one mate. The most interesting thing about monogamy and polygamy is work that
shows that a single hormone or gene is responsible for turning the one into the other. Two
species of voles show different pair bonding and behaviour characteristics: prairie voles are
monogamous, while meadow voles are polygamous. But how do we know that a vole is
monogamous? One male vole and five or six females are placed in a maze. The male smells
only one of them, and generally pays attention to and mates with that one. When these voles
lose their mate they take on the task of caring for the young and do not choose another mate.
When the brains of monogamous prairie voles were examined, it was found that there
was a high density of receptors for OXY in the accumbens nucleus, and a high density of
VZP1a receptors in the ventral pallidum. It is known that the gene for OXY production was
on chromosome 2 in prairie voles, so if this gene is knocked out, the hormone OXY can no
longer be produced. This makes a prairie vole which has been monogamous from birth
polygamous and promiscuous. He mates with any female he comes across, and takes no care
of his young. This means that pair bonding can be prevented by a single gene. And if a
substance is put into the empty spaces of the monogamous prairie vole’s brain which blocks
VZP1A receptors, this also transforms a monogamous animal into a polygamous one.
Meadow voles on the other hand are polygamous in terms of breeding habits. They do
not form pair bonds and are solitary. Their social memories are weak. When we examine the
brains of these rodents, we find that in contrast to the monogamous prairie voles, the density
of OXY and VZP1A receptors in the accumbens nuclei and ventral pallidum is low from birth.
Giving these polygamous voles intracerebral ventricular OXY makes them monogamous.
They lose their polygamous behaviour and turn into well-behaved fathers of the family.
Maybe in the future polygamous tendencies in men might be shown up in gene analysis.
Their identity cards might be marked “polygamous tendencies, good for one-night stands,
does not bond”, or otherwise “monogamous, a good father of a family”, giving women the
chance to choose accordingly.
So monogamous and polygamous behaviour in humans is also closely related to the
hormones OXY and VZP and their receptors. And receptor and hormone concentrations are
closely related to genetically related phenotypes. For humans, we have evidence for the
accumbens nucleus and the ventral pallidum which is similar to that for the brains of voles.
At the same time, fMRG studies have shown marked activity in the accumbens nucleus and
the ventral pallidum in cases of long-term bonding. This shows that the mechanisms in voles
also function in humans.
Studies on OXY have also provided similar evidence. OXY was the first peptide
hormone to be synthesised; the person who synthesised it in 1953 won the Nobel prize. OXY
is sold commercially as a nasal spray and for intravenous injection, and it is used mostly as a
common way of increasing cows’ milk production. In humans, the hormone’s characteristic
of providing “social trust” is very clear. It decreases social fear and anxiety, and it is used for
this effect in the treatment of autism. It makes it easier to gain trust in relations with another
person (both in love and when dealing with money!) When love ends or a marriage breaks
up, the reason why we say “how did I ever trust the bastard?” is most likely the fall in OXY
levels in our blood which happens alongside the reduction in bonding and trust as we come to
our senses. That is, the false sensation of trust caused by OXY has been removed.
A group of people were told to place money with an investor. If the investor gained
money they would win, but if the investor was untrustworthy and a cheat they would lose.
Some of the subjects were given a placebo nasal spray, and the others were given an OXY
spray. It was found that the group who were given the OXY nasal spray trusted the investor
more and entered into twice the risk. That is, OXY increases trust, and makes it easier to take
risks with money. In just the same way, new lovers trust each other with no regard for the
long-term consequences. However, when the same people were dealing with a computer
rather than a human investor, the OXY spray did not have the same effect. That is, this
hormone has an effect on person-to-person contacts, but not on human-to-machine
relations. For this reason, it may be recommended that people do not take decisions
involving financial risk when their OXY levels are raised by situations such as raised
oestrogen levels in menstruation, sexual activity, orgasm or breast-feeding.
When this effect became known it captured the popular commercial imagination, and
OXY-containing perfumes were produced, and marketed with slogans like “Trust is
Strength”, and “You will become irresistible, and both your social life and your wallet will be
Does all this mean that the secret of love has been stolen? When Newton explained the
colours of the rainbow by the use of a prism, the Romantic poet John Keats wrote in his poem
Do not all charms fly
At the mere touch of cold philosophy?
There was an awful rainbow once in heaven:
We know her woof, her texture; she is given
In the dull catalogue of common things.
Philosophy will clip an Angel's wings,
Conquer all mysteries by rule and line,
Empty the haunted air, and gnomed mine –
Unweave a rainbow
I don’t think we have mistreated love in the same way, because love will always keep
part of itself secret.
... Much work has been done to examine romantic love as a biological characteristic. Numerous reviews have described the neurobiology and endocrinology of romantic love (e.g., Fisher, 2004Fisher, , 2006Zeki, 2007;Hatfield and Rapson, 2009;Reynaud et al., 2010;Cacioppo et al., 2012b;de Boer et al., 2012;Diamond and Dickenson, 2012;Dunbar, 2012;Tarlaci, 2012;Xu et al., 2015;Fisher et al., 2016;Zou et al., 2016;Tomlinson et al., 2018;Walum and Young, 2018;Cacioppo, 2019). Two meta-analyses (Ortigue et al., 2010;Cacioppo et al., 2012a) considered fMRI studies of romantic love. ...
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Romantic love is a phenomenon of immense interest to the general public as well as to scholars in several disciplines. It is known to be present in almost all human societies and has been studied from a number of perspectives. In this integrative review, we bring together what is known about romantic love using Tinbergen’s “four questions” framework originating from evolutionary biology. Under the first question, related to mechanisms, we show that it is caused by social, psychological mate choice, genetic, neural, and endocrine mechanisms. The mechanisms regulating psychopathology, cognitive biases, and animal models provide further insights into the mechanisms that regulate romantic love. Under the second question, related to development, we show that romantic love exists across the human lifespan in both sexes. We summarize what is known about its development and the internal and external factors that influence it. We consider cross-cultural perspectives and raise the issue of evolutionary mismatch. Under the third question, related to function, we discuss the fitness-relevant benefits and costs of romantic love with reference to mate choice, courtship, sex, and pair-bonding. We outline three possible selective pressures and contend that romantic love is a suite of adaptions and by-products. Under the fourth question, related to phylogeny, we summarize theories of romantic love’s evolutionary history and show that romantic love probably evolved in concert with pair-bonds in our recent ancestors. We describe the mammalian antecedents to romantic love and the contribution of genes and culture to the expression of modern romantic love. We advance four potential scenarios for the evolution of romantic love. We conclude by summarizing what Tinbergen’s four questions tell us, highlighting outstanding questions as avenues of potential future research, and suggesting a novel ethologically informed working definition to accommodate the multi-faceted understanding of romantic love advanced in this review.
... Desde el punto de vista de las neuroc1encias, se han observado vanac10nes muy especificas de neurohormonas y neurotransmisores en la actividad cerebral, acordes a la duraci6n del amor romantico en la pareja (Bartels & Zeki, 2004;Emanuele et al., 2006;Esch & Stefano, 2005;Sailor, 2013;Stein & Vythilingum, 2009;Tarlaci, 2012), esto, por supuesto, no implica la causalidad exclusiva de un determinante bioquimico en la duraci6n de la relaci6n (Sailor, 2013;Ventura, 2002), como durante algun tiempo se lleg6 a especular (Hatfield & Sprecher, 1986;Jankowiak & Fischer, 1992; Parkinson, 2013) con base en los escritos de Liebowitz (1983). Sin embargo, la similitud que existe entre los efectos neuroquimicos del amor y la acci6n dopaminergica generada por ciertas drogas (Acevedo, Aron, Fisher, & Brown, 2012;Aron et al., 2005;Bartels importante distinguir las diversas fases en el progreso de una relaci6n. ...
... The brain in love(Tarlaci, 2012). ...
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Based on topological biology and structural biology, and combined the extensive quantum biology and general biological string, we propose that Calabi-Yau manifolds can provide a mathematical method to be applied to biology. Some Calabi-Yau spaces may possibly describe the biological spatial structures, in particular, in NeuroQuantology. In biology usual Calabi-Yau manifolds are also smaller and cannot be observed except microscope. It is used to superstring and brane, so may also describe some biological strings, and biological branes, etc. Further, this may combine the extensive graph theory, which includes five types of the basic elements: various solid lines, dotted lines, wavy lines, and vertices, fields. Variegated Calabi-Yau manifolds and superstring-branes correspond to multiformity of biological structures
... Reviews of these studies conclude that love is accompanied by significantly increased activation in brain regions such as the ventral tegmental area (VTA), medial insula, anterior cingulate cortex (ACC), hippocampus, nucleus accumbens (NAC), caudate nucleus, and hypothalamus. At the same time, deactivations can be found in the amygdala, prefrontal cortex (PFC), temporal poles, and temporo-parietal junction (TPJ; Zeki, 2007; de Boer et al., 2012; Diamond and Dickenson, 2012; Tarlaci, 2012). Cacioppo et al. (2012) have suggested that romantic love-related brain regions can be divided into subcortical and cortical brain networks where the former mediates reward, motivation, and emotion regulation , and the latter mainly supports social cognition, attention, memory, mental associations, and self-representation. ...
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Romantic love is a motivational state associated with a desire to enter or maintain a close relationship with a specific other person. Studies with functional magnetic resonance imaging (fMRI) have found activation increases in brain regions involved in processing of reward, emotion, motivation when romantic lovers view photographs of their partners. However, not much is known on whether romantic love affects the brain’s functional architecture during rest. In the present study, resting state functional magnetic resonance imaging (rsfMRI) data was collected to compare the regional homogeneity (ReHo) and functional connectivity (FC) across a lover group (LG, N=34, currently intensely in love), ended-love group (ELG, N=34, romantic relationship ended recently), and single group (SG, N=32, never fallen in love).The results showed that:1) ReHo of the left dorsal anterior cingulate cortex (dACC) was significantly increased in the LG (in comparison to the ELG and the SG); 2) ReHo of the left dACC was positively correlated with length of time in love in the LG, and negatively correlated with the lovelorn duration since breakup in the ELG; 3) functional connectivity (FC) within the reward, motivation, and emotion network (dACC, insula, caudate, amygdala and nucleus accumbens) and the social cognition network (temporo-parietal junction (TPJ), posterior cingulate cortex (PCC), medial prefrontal cortex (MPFC), inferior parietal, precuneus and temporal lobe) was significantly increased in the LG (in comparison to the ELG and SG); 4) in most regions within both networks FC was positively correlated with the love duration in the LG but negatively correlated with the lovelorn duration in the ELG. This study provides first empirical evidence of love-related alterations of brain functional architecture. The results shed light on the underlying neural mechanisms of romantic love, and demonstrate the possibility of applying a resting state approach for investigating romantic love.
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Šimić, N., Valerjev, P., & Nikolić Ivanišević, M. (Eds.). (2020). Mozak i um: Od električnih potencijala do svjesnog bića [Brain and Mind: From Electric Potentials to the Conscious Being]. Zadar: Sveučilište u Zadru. Iz recenzija: Mozak i um: od električnih potencijala do svjesnog bića“ se bavi pitanjem odnosa mozga i uma, odnosno, pitanjem kako moždana aktivnost stvara mentalna stanja. Ovo pitanje predstavlja jednu od najvećih neriješenih misterija i izazova za znanost u 21. stoljeću. U zadnjih četrdesetak godina, razvojem različitih tehnika za oslikavanje moždane aktivnosti, akumulirano je mnogo novih spoznaja o ovom fascinantnom pitanju. Stoga je od izuzetne važnosti napraviti pregled najvažnijih dostignuća i usmjeriti čitaoce ka proučavanju relevantne literature. Prof. dr. sc. Dražen Domijan Knjiga donosi pregled odabranih relevantnih i suvremenih tema iz neuroznanosti i znanstvene psihologije. Na taj način čitatelju omogućuje vrlo dubok uvid u mozak i um, od osnovnih spoznaja o anatomiji i fiziologiji živčanog sustava i pregleda suvremenih istraživačkih tehnika u njegovu proučavanju, preko raskrinkavanja ukorijenjenih mitova o mozgu i prikaza evolucije mozga, do vrlo zanimljivih recentnih znanstvenih spoznaja o neurofiziološkoj pozadini jezika, prostornog vida, deklarativnog pamćenja, svijesti, ljubavi i seksa, te političkog djelovanja. … Pri tome je uredništvo uspjelo u nakani da ovu, vrlo kompleksnu materiju, predstavi na jasan i razumljiv način, prilagođen visokoškolskom udžbeniku. Izv. prof. dr. sc. Ana Slišković Riječ je o moderno koncipiranom udžbeniku u kojem su odabrane teme iz područja neuroznanosti opisane na razumljiv način. S obzirom na rastuću važnost nalaza u različitim granama neuroznanosti i njihovoj sve većoj primjeni u raznim sferama ljudskog djelovanja (medicini, obrazovanju, upravljanju ljudskim potencijalima itd.) ovakve su teme itekako relevantne, a dodano je znanje iz tih područja sve traženije u raznim studijskim programima. Doc. dr. sc. Ivana Hromatko
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Despite a considerable amount of empirical studies it is still unclear if changes in union status affect body weight. Using data from the first seven waves of the German Panel Analysis of Intimate Relationships and Family Dynamics (pairfam) project, the current study aims to discover if changes in relationship status lead to changes in body weight considering multiple union transitions with fixed-effects panel regression estimations. Results show that women lose weight within the first year of a relationship, and then gain weight after entering into a non-married cohabiting relationship. Men tend to gain weight from the beginning of the partnership. The results clearly show that the transition from non-married cohabitation to marriage has no significant effect on body weight. Zusammenfassung Trotz zahlreicher Studien gibt es derzeit immer noch keine gesicherten Erkenntnisse darüber, inwieweit partnerschaftliche Veränderungen Einfluss auf das Körpergewicht haben. Basierend auf den Daten der ersten sieben Wellen des deutschen Panels Analysis of Intimate Relationships and Family Dynamics (pairfam) hat diese Studie das Ziel herauszufinden, ob Veränderungen des Beziehungsstatus zu einer Veränderung des Körpergewichts führen. Dabei werden verschiedene partnerschaftliche Übergänge mit Fixed-Effect Panel Regressionen betrachtet. Die Ergebnisse zeigen, dass Frauen in dem ersten Jahr ihrer Beziehung Gewicht verlieren, dann aber an Gewicht zunehmen, wenn sie mit ihrem Partner zusammen ziehen. Männer hingegen tendieren von Beginn an ihrer Beziehung zu einer Gewichtszunahme. Die Ergebnisse zeigen deutlich, dass der Übergang von einer nicht-ehelichen Lebensgemeinschaft zur Ehe keinen Effekt auf das Körpergewicht hat.
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Giriş ve Önsöz Kadın Orgazmının Tarihçesi Kadınlarda Orgazm Araştırmaları Kadınlarda Orgazmın Temel Fizyolojisi Kadınlarda Orgazmı Güçlendiren ve Bloke Eden Faktörler Kadınlarda Orgazm Çeşitleri Kadın Orgazmının ve Aşkın Nörobiyolojisi Kadın Cinselliği ve Hormonlar Bazı Kadınlarda Ultra Orgazm: ESR Kadınların Orgazmlarında Ekstremler: Yaşanmış Deneyimler Kadınlarda Uyarılma ve Orgazm Bozuklukları ve Anorgazmi Tedavisi Kadınlarda Haz ve Orgazm Odaklı Vajinismus Tedavisi Kadınlarda Nemfomani, Cinsel Bağımlılık, Patolojik Hiperseksüelite, Parafililer ve Tedavisi Kadın Cinselliğini ve Orgazmlarını Geliştirmek Ders Kitabı için Sınav Soruları Kaynakça Yazar hakkında bilgi Tanıtımlar
Starting from three clinical vignettes representing two psychological disorders and different approaches to their treatment, the question is raised concerning how an unexpected event occurring at a particular time in a person's life could arouse emotions that were so strong as to determine the transition from a state of severe distress to one of sudden wellbeing. The analysis of these three clinical cases allows us to observe the relative importance of biological predisposition and environmentally influenced brain plasticity, of the psychotherapeutic process and of positive emotions (especially trust, the sense of being cared for, and falling in love) produced by openness to novelty and the Other. From a neurobiological standpoint, it may be assumed that this sudden improvement might be related to an oxytocinergic action which, in synergy with the dopaminergic circuits, is able to restore a state of wellbeing, safe attachment and gratification. This article is protected by copyright. All rights reserved. © 2015 Wiley Periodicals, Inc.
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In humans, interpersonal romantic attraction and the subsequent development of monogamous pair-bonds is substantially predicted by influential impressions formed during first encounters. The prosocial neuropeptide oxytocin (OXT) has been identified as a key facilitator of both interpersonal attraction and the formation of parental attachment. However, whether OXT contributes to the maintenance of monogamous bonds after they have been formed is unclear. In this randomized placebo-controlled trial, we provide the first behavioral evidence that the intranasal administration of OXT stimulates men in a monogamous relationship, but not single ones, to keep a much greater distance (∼10-15 cm) between themselves and an attractive woman during a first encounter. This avoidance of close personal proximity occurred in the physical presence of female but not male experimenters and was independent of gaze direction and whether the female experimenter or the subject was moving. We further confirmed this unexpected finding using a photograph-based approach/avoidance task that showed again that OXT only stimulated men in a monogamous relationship to approach pictures of attractive women more slowly. Importantly, these changes cannot be attributed to OXT altering the attitude of monogamous men toward attractive women or their judgments of and arousal by pictures of them. Together, our results suggest that where OXT release is stimulated during a monogamous relationship, it may additionally promote its maintenance by making men avoid signaling romantic interest to other women through close-approach behavior during social encounters. In this way, OXT may help to promote fidelity within monogamous human relationships.
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Love has long been referred to as an addiction in literature and poetry. Scientists have often made comparisons between social attachment processes and drug addiction, and it has been suggested that the two may share a common neurobiological mechanism. Brain systems that evolved to govern attachments between parents and children and between monogamous partners may be the targets of drugs of abuse and serve as the basis for addiction processes. Here, we review research on drug addiction in parallel with research on social attachments, including parent-offspring attachments and social bonds between mating partners. This review focuses on the brain regions and neurochemicals with the greatest overlap between addiction and attachment and, in particular, the mesolimbic dopamine (DA) pathway. Significant overlap exists between these two behavioral processes. In addition to conceptual overlap in symptomatology, there is a strong commonality between the two domains regarding the roles and sites of action of DA, opioids, and corticotropin-releasing factor. The neuropeptides oxytocin and vasopressin are hypothesized to integrate social information into attachment processes that is not present in drug addiction. Social attachment may be understood as a behavioral addiction, whereby the subject becomes addicted to another individual and the cues that predict social reward. Understandings from both fields may enlighten future research on addiction and attachment processes.
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Research on the neurobiology of parenting has defined biobehavioral synchrony, the coordination of biological and behavioral responses between parent and child, as a central process underpinning mammalian bond formation. Bi-parental rearing, typically observed in monogamous species, is similarly thought to draw on mechanisms of mother-father synchrony. We examined synchrony in mothers' and fathers' brain response to ecologically valid infant cues. Thirty mothers and fathers, comprising 15 couples parenting 4- to 6-month-old infants, were visited at home, and infant play was videotaped. Parents then underwent functional magnetic resonance imaging scanning while observing own-infant compared with standard-infant videos. Coordination in brain response between mothers and fathers was assessed using a voxel-by-voxel algorithm, and gender-specific activations were also tested. Plasma oxytocin and arginine vasopressin, neuropeptides implicated in female and male bonding, were examined as correlates. Online coordination in maternal and paternal brain activations emerged in social-cognitive networks implicated in empathy and social cognition. Mothers showed higher amygdala activations and correlations between amygdala response and oxytocin. Fathers showed greater activations in social-cognitive circuits, which correlated with vasopressin. Parents coordinate online activity in social-cognitive networks that support intuitive understanding of infant signals and planning of adequate caregiving, whereas motivational-limbic activations may be gender specific. Although preliminary, these findings demonstrate synchrony in the brain response of two individuals within an attachment relationship, and may suggest that human attachment develops within the matrix of biological attunement and brain-to-brain synchrony between attachment partners.
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We pursued our functional magnetic resonance imaging (fMRI) studies of the neural correlates of romantic love in 24 subjects, half of whom were female (6 heterosexual and 6 homosexual) and half male (6 heterosexual and 6 homosexual). We compared the pattern of activity produced in their brains when they viewed the faces of their loved partners with that produced when they viewed the faces of friends of the same sex to whom they were romantically indifferent. The pattern of activation and de-activation was very similar in the brains of males and females, and heterosexuals and homosexuals. We could therefore detect no difference in activation patterns between these groups.
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The early stages of a new romantic relationship are characterized by intense feelings of euphoria, well-being, and preoccupation with the romantic partner. Neuroimaging research has linked those feelings to activation of reward systems in the human brain. The results of those studies may be relevant to pain management in humans, as basic animal research has shown that pharmacologic activation of reward systems can substantially reduce pain. Indeed, viewing pictures of a romantic partner was recently demonstrated to reduce experimental thermal pain. We hypothesized that pain relief evoked by viewing pictures of a romantic partner would be associated with neural activations in reward-processing centers. In this functional magnetic resonance imaging (fMRI) study, we examined fifteen individuals in the first nine months of a new, romantic relationship. Participants completed three tasks under periods of moderate and high thermal pain: 1) viewing pictures of their romantic partner, 2) viewing pictures of an equally attractive and familiar acquaintance, and 3) a word-association distraction task previously demonstrated to reduce pain. The partner and distraction tasks both significantly reduced self-reported pain, although only the partner task was associated with activation of reward systems. Greater analgesia while viewing pictures of a romantic partner was associated with increased activity in several reward-processing regions, including the caudate head, nucleus accumbens, lateral orbitofrontal cortex, amygdala, and dorsolateral prefrontal cortex--regions not associated with distraction-induced analgesia. The results suggest that the activation of neural reward systems via non-pharmacologic means can reduce the experience of pain.
Nerve growth factor (NGF) is largely known as a target-derived factor responsible for the survival and maintenance of the phenotype of specific subsets of peripheral neurones and basal forebrain cholinergic nuclei during development and maturation. However, NGF also exerts a modulatory role on sensory, nociceptive nerve physiology during adulthood that appears to correlate with hyperalgesic phenomena occurring in tissue inflammation. Other NGF-responsive cells are now recognized as belonging to the haemopoietic-immune system and to populations in the brain involved in neuroendocrine functions. The concentration of NGF is elevated in a number of inflammatory and autoimmune states in conjunction with an increased accumulation of mast cells. Mast cells and NGF appear to be involved in neuroimmune interactions and tissue inflammation, with NGF acting as a general ‘alert’ molecule capable of recruiting and priming tissue defence processes following insult as well as systemic defensive mechanisms. Moreover, mast cells themselves produce NGF, suggesting that alterations in normal mast cell behaviours can provoke maladaptive neuroimmune tissue responses whose consequences could have profound implications in inflammatory disease states. This review discusses recent discoveries involving novel and diverse biological activities of this fascinating molecule.Trends Neurosci. (1996) 19, 514–520
The neuropeptide oxytocin has had key roles throughout mammalian evolution in the regulation of complex social cognition and behaviors, such as attachment, parental care, pair-bonding, as well as social exploration and recognition. Recently, studies have begun to provide evidence that the function of this neuropeptide is impaired in mental disorders associated with social deficits. In this review, we focus on the genetic mechanisms of inter-individual variation in the social neuropeptide signaling. We discuss molecular genetic studies which identified variations in specific genes contributing to individual differences in social behavior and cognition, with a focus on the gene coding for the oxytocin receptor (OXTR) emerging as a particularly promising candidate. We conclude that molecular studies are warranted to elucidate functional consequences of variants that have shown stable associations with sociobehavioral phenotypes. With regard to the variability in individual responses to oxytocin administration, we advocate the need for pharmacogenetic approaches in order to test how the efficacy of oxytocin administration is modulated by genetic variation of OXTR or other genes involved in oxytocin signaling.
Background: The social milieu provides the context for the organism's survival, endurance, and adaptation. In mammals, social participation originates within the parent-infant bond and is supported by the oxytocin (OT) system, whose functioning is transmitted from parent to child through patterns of parental care. Human studies indicate that OT administration increases affiliative behavior, including trust, empathy, and social reciprocity. Here, we examine whether OT administration to parent can enhance physiological and behavioral processes that support parental social engagement but, moreover, can have parallel effects on the infant. Methods: Utilizing a double-blind, placebo-controlled crossover design, 35 fathers and their 5-month-old infants were observed twice following administration of OT or placebo to father in the face-to-face still-face paradigm. Parent and infant salivary OT were assessed at multiple time points, respiratory sinus arrhythmia (RSA) was measured in the three face-to-face still-face episodes, and social behaviors of the parent and child were micro-coded for indices of social engagement. Results: Oxytocin administration increased father salivary OT, RSA during free play, and key parenting behaviors that support parental-infant bonding. Parallel increases were also found in the infant's salivary OT, RSA response, and engagement behavior, including social gaze, exploration, and social reciprocity. Conclusions: Results are the first to demonstrate that OT administration to one attachment partner can have parallel effects on the other and underscore the role of OT in the cross-generation transmission of human social participation. Findings have translational implications for conditions associated with early risk for social-emotional growth, including autism and prematurity, without the need to administer drugs to young infants.
Oxytocin, an octapeptide synthesized in the hypothalamus, stimulates milk election and uterine contractions. In the brain this hormone acts as a neuropeptide. It could inhibit through the GABAergic system the activity of limbic amygdala, which is involved in the response to fear. Oxytocin could also induce the protective behaviour of the mother towards its offspring through the dopaminergic system. In mankind, oxytocin plays a role in trust, empathy, generosity, stress and sexuality. Clinical studies are testing potential benefits of oxytocin administration in autism, depression and social phobia. Results are still preliminary.
Romantic love is the catalyst behind the spread of the human life. The neurobiology of love embraces the hypothesis that what we call "romantic attachment" or "romantic love" may be at least in part the expression of biological factors. A corollary of this hypothesis states that it is possible to learn much about the nature of human love by studying the molecules involved in the expression of social and affiliative behaviours. Under this theoretical framework, we have investigated the changes in plasma neurotrophin levels in subjects with early stage romantic love. A positive association between the intensity of early romantic feelings and serum levels of nerve growth factor (NGF) has been identified. These findings link love with biologically relevant pathways for neuron survival and illuminate the biochemical correlates of such a complex feeling that so deeply affects our own lives. The progresses in the neurobiology of love suggest that this kind of research may open a new window onto our understanding of the very nature of human romantic bonding.