Ignacio Torres-Aleman

• PhD
• Professor (Full) at Achucarro Basque Center for Neuroscience

The sheer amplitude of biological actions of insulin-like growth factor I (IGF-1) affecting all types of cells in all tissues suggests a vast signaling landscape for this ubiquitous humoral signal. While the canonical signaling pathways primarily involve the Ras/MAPK and PI3K/AKT cascades, the evolutionary conservation of insulin-like peptides (ILP...

Insulin-like growth factor-I (IGF-I) plays a key role in the modulation of synaptic plasticity and is an essential factor in learning and memory processes. However, during aging, IGF-I levels are decreased, and the effect of this decrease in the induction of synaptic plasticity remains unknown. Here we show that the induction of N-methyl-D-aspartat...

Insulin-like growth factor-I (IGF-I) plays a key role in the modulation of synaptic plasticity, and is an essential factor in learning and memory processes. Indeed, we have demonstrated that IGF-IR activation induces long-term potentiation (LTP) of synaptic transmission (LTP IGF-I ) both in the barrel cortex, improving object recognition (Noriega-P...

Background Pleiotropic actions of insulin and insulin‐like growth factor I (IGF‐I) in the brain are context‐ and cell‐dependent, but whether this holds for their receptors (insulin receptor (IR) and IGF‐I receptor (IGF‐IR), respectively), is less clear. Methods We compared mice lacking IR or IGF‐IR in glial fibrillary astrocytic protein (GFAP)‐exp...

Increased neurotrophic support, including insulin-like growth factor I (IGF-I), is an important aspect of the adaptive response to ischemic insult. However, recent findings indicate that the IGF-I receptor (IGF-IR) in neurons plays a detrimental role in the response to stroke. Thus, we investigated the role of astrocytic IGF-IR on ischemic insults...

Despite decades of intense research, disease-modifying therapeutic approaches for Alzheimer’s disease (AD) are still very much needed. Apart from the extensively analyzed tau and amyloid pathological cascades, two promising avenues of research that may eventually identify new druggable targets for AD are based on a better understanding of the mecha...

Insulin-like growth factor-I (IGF-I) exerts multiple actions, yet the role of IGF-I from different sources is poorly understood. Here, we explored the functional and behavioral consequences of the conditional deletion of Igf-I in the nervous system (Igf-I Δ/Δ), and demonstrated that long-term potentiation was impaired in hippocampal slices. Moreove...

After decades of research in the neurobiology of IGF-I, its role as a prototypical neurotrophic factor is undisputed. However, many of its actions in the adult brain indicate that this growth factor is not only involved in brain development or in the response to injury. Following a three-layer assessment of its role in the central nervous system, w...

Since neurons were first cultured outside a living organism more than a century ago, a number of experimental techniques for their in vitro maintenance have been developed. These methods have been further adapted and refined to study specific neurobiological processes under controlled experimental conditions. Despite their limitations, the simplici...

Insulin-like Growth Factor I (IGF-I) is a peptide involved in many processes in the brain. Recently, we described how IGF-I modulates sleep behavior, response to stress, and its role in cognition through cholinergic, orexinergic, and locus coeruleus nuclei. Nonetheless, IGF-I modulation of social behavior remains explored, especially during aging a...

Aging is a physiological process accompanied by a decline in cognitive performance. The cholinergic neurons of the basal forebrain provide projections to the cortex that are directly engaged in many cognitive processes in mammals. In addition, basal forebrain neurons contribute to the generation of different rhythms in the EEG along the sleep/wakef...

Increased neurotrophic support, including insulin-like growth factor I (IGF-I), is an important aspect of the adaptive response to ischemic insult. However, recent findings indicate that the IGF-I receptor (IGF-IR) in neurons plays a detrimental role in the response to stroke. Thus, we investigated the role of astrocytic IGF-IR on ischemic insults...

Background: Pleiotropic actions of insulin and insulin-like growth factor I (IGF-I) in the brain are context- and cell-dependent, but whether this holds for their receptors (insulin receptor (IR) and IGF-I receptor (IGF-IR), respectively), is less clear. Methods: We compared mice lacking IR or IGF-IR in glial fibrillary astrocytic protein (GFAP)-ex...

Background: Pleiotropic actions of insulin and insulin-like growth factor I (IGF-I) in the brain are context- and cell-dependent, but whether this holds for their receptors (insulin receptor (IR) and IGF-I receptor (IGF-IR), respectively), is less clear. Methods: We compared mice lacking IR or IGF-IR in glial fibrillary astrocytic protein (GFAP)-ex...

Mice with insulin receptor (IR)–deficient astrocytes (GFAP-IR knockout [KO] mice) show blunted responses to insulin and reduced brain glucose uptake, whereas IR-deficient astrocytes show disturbed mitochondrial responses to glucose. While exploring the functional impact of disturbed mitochondrial function in astrocytes, we observed that GFAP-IR KO...

Background: Pleiotropic actions of insulin and insulin-like growth factor I (IGF-I) in the brain are context- and cell-dependent, but whether this holds for their receptors (insulin receptor (IR) and IGF-I receptor (IGF-IR), respectively), is less clear. Methods: We compared mice lacking IR or IGF-IR in glial fibrillary astrocytic protein (GFAP)-ex...

Sleep disturbances are common during aging. Compared to young animals, old mice show altered sleep structure, with changes in both slow and fast electrocorticographic (ECoG) activity and fewer transitions between sleep and wake stages. Insulin-like growth factor I (IGF-I), which is involved in adaptive changes during aging, was previously shown to...

Uncoupling of metabolism and circadian activity is associated with an increased risk of a wide spectrum of pathologies. Recently, insulin and the closely related insulin-like growth factor I (IGF-I) were shown to entrain feeding patterns with circadian rhythms. Both hormones act centrally to modulate peripheral glucose metabolism; however, whereas...

Maladaptive coping behaviors are probably involved in post-traumatic stress disorders (PTSD), but underlying mechanisms are incompletely understood. We now report that mice lacking functional insulin-like growth factor I (IGF-I) receptors in orexin neurons of the lateral hypothalamus (Firoc mice) are unresponsive to the anxiolytic actions of IGF-I...

Aging is accompanied by a decline in cognition that can be due to a lower IGF-I level. We studied response facilitation induced in primary somatosensory (S1) cortical neurons by repetitive stimulation of whiskers in young and old mice. Layer 2/3 and 5/6 neurons were extracellularly recorded in young (≤ 6 months of age) and old (≥ 20 month of age) a...

Background: It is known that IGF-I facilitates a waking state and modulates sleep architecture through the activation of orexinergic neurons. However, IGF-I may activate other neurons that may facilitate waking states, such as the locus coeruleus and the basal forebrain, orchestrating an intricate role in brain and cortical regulation. The BF is a...

Background: Sleep disturbances are common during aging. Old mice show altered sleep structure, with changes in both slow and fast electro-corticographic (ECG) activity, and less transitions between sleep and wake stages, as compared to young animals. Insulin-like growth factor I (IGF-I), that is involved in hormonal changes during aging, was previ...

It is known that aging is frequently accompanied by a decline in cognition. Furthermore, aging is associated with lower serum IGF-I levels that may contribute to this deterioration. We studied the effect of IGF-I in neurons of the horizontal diagonal band of Broca (HDB) of young (≤6 months old) and old (≥20-month-old) mice to determine if changes i...

Brain regulation of bodily functions requires interoceptive feedback signals carrying information about the periphery. As mice with low serum IGF-I levels (LID mice) show reduced spontaneous physical activity, we speculated that body vigor information might be conveyed by circulating IGF-I, a regulator of skeletal muscle and bone mass that enters t...

Insulin-like growth factor-I (IGF-I) signaling plays a key role in learning and memory processes. While the effects of IGF-I on neurons have been studied extensively, the involvement of astrocytes in IGF-I signaling and the consequences on synaptic plasticity and animal behavior remain unknown. We have found that IGF-I induces long-term potentiatio...

Sleep disturbances are common during aging. Compared to young animals, old mice show altered sleep structure, with changes in both slow and fast lectrocorticographic (ECoG) activity and fewer transitions between sleep and wake stages. Insulin-like growth factor I (IGF-I), which is involved in adaptive changes during aging, was previously shown to i...

Uncoupling of metabolism and circadian activity is associated with an increased risk of various pathologies, including neurodegeneration. Recently, insulin and the closely related insulin-like growth factor I (IGF-I) were shown to entrain feeding patterns with circadian rhythms. Moreover, both hormones act centrally to modulate peripheral glucose m...

Obesity is a risk factor for Alzheimer’s disease (AD), but underlying mechanisms are not clear. We analyzed peripheral clearance of amyloid β (Aβ) in overweight mice because its systemic elimination may impact brain Aβ load, a major landmark of AD pathology. We also analyzed whether circulating insulin-like growth factor I (IGF-I) intervenes in the...

Background Aging and dementia are related to sleep and circadian disturbances. These disturbances are attributed to neurodegeneration of brain networks involved in sleep. On the other hand, increasing evidence supports the notion that Alzheimer’s disease (AD), a condition that presents heterogeneous pathological disturbances, including sleep regula...

Although sleep disturbances are common co‐morbidities of metabolic diseases, the underlying processes linking both are not yet fully defined. Changes in the duration of sleep are paralleled by changes in the levels of insulin‐like growth factor‐I (IGF‐I), an anabolic hormone that shows a circadian pattern in the circulation and activity‐dependent e...

Background Obesity is a risk factor for Alzheimer´s disease (AD), but underlying mechanisms are not clear.Methods We analyzed peripheral clearance of amyloid β (Aβ) in overweight mice because its systemic elimination may impact on brain Aβ load, a major landmark of AD pathology. We also analyzed whether circulating insulin-like growth factor I (IGF...

Obesity is a risk factor for Alzheimer disease (AD), but underlying mechanisms are not clear. We analyzed peripheral clearance of amyloid-beta (Abeta) in overweight mice because its systemic elimination may impact on brain Abeta load, a major landmark of AD pathology. Overweight mice showed increased peripheral Abeta clearance by the liver, the maj...

Although metabolic and sleep disturbances are commonly associated, the underlying processes are not yet fully defined. Insulin-like growth factor-I (IGF-I), an anabolic hormone that shows a circadian pattern in the circulation, is associated to sleep regulation along evolution. However, its role in this universal homeostatic process remains poorly...

Insulin-like growth factor-I (IGF-I) signaling plays key regulatory roles in multiple processes of brain physiology and pathology. While the direct effects of IGF-I in neurons have been extensively studied, the astrocyte involvement in IGF-I signaling and the consequences on synaptic plasticity and animal behavior remain unknown. Here we show that...

Knowledge of mechanisms involved in vulnerability/resilience to stress disorders is crucial for prevention and treatment schemes. We previously documented that insulin-like growth factor I (IGF-I) is associated to vulnerability to stress both in mice and humans. Since hypothalamic orexin neurons express IGF-I receptors and are involved in responses...

Increasing evidence supports the notion that Alzheimer´s disease (AD), a condition that presents heterogeneous pathology, is also associated with perturbed metabolic function affecting insulin and insulin-like growth factor I (IGF-I). Thus, whether IGF-I is beneficial or detrimental to brain function in general, and to AD in particular, has led to...

Circulating insulin enters into the brain through mechanisms that are not yet entirely understood. We now report that mice lacking insulin receptors (IR) in astrocytes show reduced uptake of circulating insulin and blunted brain responses to this circulating hormone, suggesting that astrocytes form part of the cellular pathway in the entrance of ci...

Increasing evidence supports the notion that Alzheimer’s disease (AD), a condition that presents heterogeneous pathological disturbances, is also associated to perturbed metabolic function affecting insulin and insulin-like growth factor I (IGF-I). While impaired insulin activity leading to insulin resistance has been associated to AD, whether alte...

We recently reported that exercise increases resilience to stress in young female mice. Underlying mechanisms include an interaction of the ovarian hormone estradiol (E2) with insulin-like growth factor I (IGF-I), and an increase in the hippocampal levels of the latter. Since changes in mood regulation during aging may contribute to increasing inci...

Changes in cerebral blood flow (CBF) and in the expression of angiogenic growth factors are observed in Alzheimer´s disease (AD), but whether these alterations precede or are a consequence of AD is not yet known. We now explore the role of the insulin receptor (IR) in astrocytes because animals lacking these receptors (GFAP-IR KO mice) show reduced...

Individual susceptibility to anxiety disorders after maladaptive responses to stress is not well understood. We now report that while exploring stress responses in mice after traumatic brain injury (TBI), a condition associated to stress susceptibility, we observed that the anxiogenic effects of either TBI or exposure to life-threatening experience...

The search for the cause of Alzheimer’s disease (AD), that affects millions of people worldwide, is currently one of the most important scientific endeavors from a clinical perspective. There are so many mechanisms proposed, and so disparate changes observed, that it is becoming a challenging task to provide a comprehensive view of possible pathoge...

Astrocytes are major players in brain glucose metabolism, supporting neuronal needs on demand through mechanisms that are not yet entirely clear. Understanding glucose metabolism in astrocytes is therefore of great consequence to unveil novel targets and develop new drugs to restore brain energy balance in pathology. Contrary to what has been held...

Age is the main risk factor for Alzheimer´s disease (AD). With an increasingly aging population, development of affordable screening techniques to determine cognitive status will help identify population-at-risk for further follow-up. Because physical exercise is known to modulate cognitive performance, we used it as a functional test of cognitive...

A, Aβ immunostaining of control (WT) and APP/PS1 (AD) show the presence of small deposits (Aβ plaques) only in the latter. B, Time line of experimental procedure for Y maze plus exercise used in the experiments shown in Fig 2. C, Both sedentary (white bars) and exercised (grey bars) wild type mice learn the Y maze task as indicated by increased ent...

In response to injury, the brain produces different neuroprotective molecules, such as insulin-like growth factor I (IGF-I). However, IGF-I is also taken up by the brain from the circulation in response to physiological stimuli. Herein, we analyzed in mice the relative contribution of circulating and locally produced IGF-I to increased brain IGF-I...

Aims/hypothesisType 2 diabetes is likely to be an independent risk factor for hippocampal-based memory dysfunction, although this complication has yet to be investigated in detail. As dysregulated glycometabolism in peripheral tissues is a key symptom of type 2 diabetes, it is hypothesised that diabetes-mediated memory dysfunction is also caused by...

Inherited neurodegenerative diseases such as Friedreich's ataxia (FRDA), produced by deficiency of the mitochondrial chaperone frataxin (Fxn), shows specific neurological deficits involving different subset of neurons even though deficiency of Fxn is ubiquitous. Because astrocytes are involved in neurodegeneration, we analyzed whether they are also...

The role of IGF-1 and its receptor (IGF-1R) in brain pathology is still unclear. Thus, either reduction of IGFIR or treatment with IGF-1, two apparently opposite actions, has proven beneficial in brain diseases such as Alzheimer's dementia. A possible explanation of this discrepancy is that IGF-1 down-regulates brain IGF-1R levels, as previously se...

Aging impairs cerebrovascular plasticity and subsequently leads cerebral hypoperfusion, which synergistically accelerates aging-associated cognitive dysfunction and neurodegenerative diseases associated with impaired neuronal plasticity. On the other hand, over two decades of researches have successfully demonstrated that exercise, or higher level...

The role of insulin-like growth factor I (IGF-I) and its receptor (IGF-IR) in brain pathology is still unclear. Thus, either reduction of IGF-IR or treatment with IGF-I, two apparently opposite actions, has proven beneficial in brain diseases such as Alzheimer´s dementia (AD). A possible explanation of this discrepancy is that IGF-I down-regulates...

Brain activity requires a flux of glucose to active regions to sustain increased metabolic demands. Insulin, the main regulator of glucose handling in the body, has been traditionally considered not to intervene in this process. However, we now report that insulin modulates brain glucose metabolism by acting on astrocytes in concert with IGF-I. The...

We report that astrocytic insulin signaling co-regulates hypothalamic glucose sensing and systemic glucose metabolism. Postnatal ablation of insulin receptors (IRs) in glial fibrillary acidic protein (GFAP)-expressing cells affects hypothalamic astrocyte morphology, mitochondrial function, and circuit connectivity. Accordingly, astrocytic IR ablati...

PI3K proteins family have multiple and essential functions in most cellular events. This family is composed of class I, class II and class III PI3Ks, which upstream and downstream elements are not completely elucidated. Previous studies using the broad PI3K inhibitor, LY294002 allowed to propose that PI3 kinase > Akt pathway is a key element in the...

Previous findings indicate that reducing brain insulin-like growth factor I receptor (IGF-IR) activity promotes ample neuroprotection. We now examined a possible action of IGF-IR on brain glucose transport to explain its wide protective activity, as energy availability is crucial for healthy tissue function. Using (18) FGlucose PET we found that sh...

Mood homeostasis present sexually dimorphic traits which may explain sex differences in the incidence of mood disorders. We explored whether diverse behavioral-setting components of mood may be differentially regulated in males and females by exercise, a known modulator of mood. We found that exercise decreases anxiety only in males. Conversely, ex...

Astrocytes actively participate in neuro-inflammatory processes associated to Alzheimer’s disease (AD), and other brain pathologies. We recently showed that an astrocyte-specific intracellular signaling pathway involving an interaction of the phosphatase calcineurin with the transcription factor FOXO3 is a major driver in AD-associated pathological...

Disruption of insulin-like growth factor I (IGF-I) signaling is a key step in the development of cancer or neurodegeneration. For example, interference of the pro-survival IGF-I/AKT/FOXO3 pathway by redox activation of the stress kinases P38 and JNK is instrumental in neuronal death by oxidative stress. However, in astrocytes IGF-I retains its prot...

Several decades ago, the observation that Alzheimer's disease (AD) presents early disturbances in brain glucose metabolism prompted the notion of insulin dysregulation in this condition. Since then, abundant epidemiological evidence has associated AD to insulin resistance as in type 2 diabetes mellitus (T2DM). However, because the role of insulin i...

Reducing insulin-like growth factor I receptor (IGF-IR) levels or administration of IGF-I show beneficial effects in the brain. We now provide evidence to help resolve this paradox. The unliganded IGF-IR inhibits glucose uptake by astrocytes while its stimulation with IGF-I, in concert with insulin activation of the insulin receptor, produces the o...

The objective of this clinical open-label trial was to test the safety, tolerability and efficacy of IGF-1 therapy for autosomal dominant cerebellar ataxia (ADCA) patients. A total of 19 molecularly confirmed patients with SCA3, 1 patient with SCA6 and 6 patients with SCA7 completed our study. They were 8 females and 18 males, 28 to 74 years of age...

Friedreich’s ataxia is an autosomal recessive, severely incapacitating disorder. There is little objective evidence regarding FRDA management. Abnormalities in the insulin/insulin-like growth factor 1 (IGF-1) system (IIS) signalling pathway were thought to play a role in the physiopathological processes of various neurodegenerative disorders, inclu...

Oxidative stress is a proposed mechanism in brain aging, making the study of its regulatory processes an important aspect of current neurobiological research. In this regard, the role of the aging regulator insulin-like growth factor I (IGF-I) in brain responses to oxidative stress remains elusive as both beneficial and detrimental actions have bee...

Oxidative stress is a proposed mechanism in brain aging, making the study of its regulatory processes an important aspect of current neurobiological research. In this regard, the role of the aging regulator insulin-like growth factor I (IGF-I) in brain responses to oxidative stress remains elusive as both beneficial and detrimental actions have bee...

Circulating insulin-like growth factor I (IGF-I) enters the brain and promotes clearance of amyloid peptides known to accumulate in Alzheimer's disease (AD) brains. Both patients and mouse models of AD show decreased level of circulating IGF-I enter the brain as evidenced by a lower ratio of cerebrospinal fluid/plasma IGF-I. Importantly, in presymp...

Loss-of-function mutations in the phosphatase PTEN (phosphatase and tensin homolog deleted on chromosome10) contribute to aberrant cell growth in part through upregulation of the mitogenic IGF-1/PI3K/Akt pathway. In turn, this pathway exerts a homeostatic feedback over PTEN. Using mutagenesis analysis to explore a possible impact of this mutual con...

While increasing evidence demonstrates that physical exercise promotes brain health, little is known on how the reduction of physical activity affects brain function. We investigated whether the cessation of wheel running alters anxiety-like and depression-like behaviors and its impact on adult hippocampal neurogenesis in mice. Male C57BL/6 mice (4...

Background Friedreich’s ataxia (FRDA) is a neurodegenerative disease caused by deficiency of the mitochondrial iron chaperone frataxin (Fxn). FRDA has no cure, but disease-modifying strategies to increase frataxin are under study. Because insulin-like growth factor I (IGF-I) has therapeutic effects in various types of cerebellar ataxia and exerts p...

The previously undisputed neuroprotective role of insulin-like growth factor 1 (IGF-1) has been challenged by recent observations in IGF-1 receptor (IGF-1R) defective mutants. As new ligand-dependent and ligand-independent roles for IGF-1R are now emerging, new insights into the biologic role of brain IGF-1R and its connection with serum and brain...

Central and peripheral insulin-like peptides (ILPs), which include insulin, insulin-like growth factor 1 (IGF1) and IGF2, exert many effects in the brain. Through their actions on brain growth and differentiation, ILPs contribute to building circuitries that subserve metabolic and behavioural adaptation to internal and external cues of energy avail...

The influence of insulin-like growth factor I (IGF-I) on the progression of Alzheimer's disease (AD) is discussed controversially. To help clarify the role of this circulating neurotrophic factor in brain amyloidosis, the major pathological trait in AD, we analyzed plaque formation in a mouse model of AD transgenic for human APP and PS1 mutations w...

Whether insulin-like growth factor I (IGF-I) signaling in Alzheimer's disease (AD) is beneficial or detrimental remains controversial. We now show that a competitive regulation by IGF-I of the phosphatase calcineurin in reactive, but not in quiescent astrocytes drives Alzheimer's pathology. Calcineurin de-phosphorylates the transcription factor Fox...

Increasing evidence indicates that physical exercise induces adaptations at the cellular, molecular, and systemic levels that positively affect the brain. Insulin plays important functional roles within the brain that are mediated by insulin-receptor (IR) signaling. In the hippocampus, insulin improves synaptic plasticity, memory formation, and lea...

Peripheral insulin-like growth factor I (IGF-I) function progressively deteriorates with age. However, whereas deterioration of IGF-I function in the aged brain seems probable, it has not been directly addressed yet. Because serum IGF-I can enter into the brain through the cerebrospinal fluid (CSF), we examined this route of entrance in aged mice....

The synthesis of composite nanoparticles consisting of a magnetite core coated with a layer of the hormone insulin growth factor 1 (IGF-1) is described. The adsorption of the hormone in the different formulations is first studied by electrophoretic mobility measurements as a function of pH, ionic strength, and time. Because of the permeable charact...

Spinocerebellar ataxias (SCAs) constitute a group of autosomal dominant neurodegenerative disorders with no current treatment. The insulin/insulin-like growth factor 1 (IGF-1) system (IIS) has been shown to play a role in the neurological dysfunction of SCAs and other polyglutamine disorders. We aimed to study the biomarker profile of serum IIS com...

Insulin-like growth factors (IGFs) are important modulators of organismal life-span all along phylogeny. These growth factors are widely viewed as detrimental for long life by reducing tissue resistance to oxidative stress. However, IGF-I has been consistently shown to be a potent neuroprotective factor in mammals, and as such, a deterrent of brain...

The ancient insulin-like family of peptides gave rise in higher organisms to insulin-growth factors (IGFs) and insulin. Formerly considered functionally divergent, new evidence suggests that IGFs and insulin probably share a close functional relationship. These links are still poorly defined but may eventually turn out to be of great relevance in t...

Upon entry into the central nervous system (CNS), serum insulin-like growth factor-1 (IGF-I) modulates neuronal growth, survival, and excitability. Yet mechanisms that trigger IGF-I entry across the blood-brain barrier remain unclear. We show that neuronal activity elicited by electrical, sensory, or behavioral stimulation increases IGF-I input in...

Insulin-like growth factor I (IGF-I) belongs to an ancient family of hormones already present in early invertebrates. The insulin family is well characterized in mammals, although new members have been described recently. Since its characterization over 50 years ago, IGF-I has been considered a peptide mostly involved in the control of body growth...

While physical exercise clearly has beneficial effects on the brain, fomenting neuroprotection as well as promoting neural plasticity and behavioural modifications, the cellular and molecular mechanisms mediating these effects are not yet fully understood. We have analyzed sedentary and exercised animals to examine the effects of activity on behavi...

Reduced brain input of serum insulin-like growth factor I (IGF-I), a potent neurotrophic peptide, may be associated with neurodegenerative processes. Thus, analysis of the mechanisms involved in passage of blood-borne IGF-I into the brain may shed light onto pathological mechanisms in neurodegeneration and provide new drug targets. A site of entran...

Insulin-like growth factor I (IGF-I) is central to the somatotropic (growth hormone) axis. It promotes tissue growth and continues to have anabolic effects in adulthood. Accumulating evidence from the last decade, however, reveals that circulating levels of IGF-I also significantly affects cognitive brain function. Specifically, the decline of seru...

This review addresses the role of serum insulin-like growth factor 1 (IGF1) as one mechanism of adult neural plasticity, specifically, its regulation of hippocampal neurogenesis among other plasticity-related processes. It is suggested that IGF has been reused advantageously both for the control of energy expenditure as a function of the organism's...

Peripheral and central diabetic neuropathies were studied in streptozotocin-diabetic rats, using behavioral, biochemical and electrophysiological techniques. Diabetic rats showed thermal hypoalgesia and decreasing motor nerve conduction velocity at 4 and 8 weeks of diabetes. In addition, amplitude of the evoked potential recorded in primary somatos...

It is lay knowledge now that Alzheimer's dementia (AD) is one of the most devastating diseases afflicting our societies. A major thrust in search for a cure has relied in the development of animal models of the disease. Thanks to progress in the genetics of the rare inherited forms of AD, various transgenic mouse models harboring human mutated prot...