Marisa Pedemonte

Facultad de Medicina, Centro Latinoamericano de Economía Humana, Punta del Este, Uruguay · Physiology

It is known that changes in neuronal activity occur during the sleep-wake cycle along the entire auditory pathway. Subjective tinnitus is an anomalous auditory perception resulting from dysfunction of neuronal plasticity. A therapeutic strategy using acoustic stimulation with sound mimicking tinnitus during sleep was developed, resulting in decreas...

Advances in science and research methods have demonstrated that sleep is not a quiescent state as we initially thought. The development of electroencephalography and electromyography leads to the identification and differentiation of sleep stages. The initial sleep-staging criteria of Rechtschaffen and Kales used electroencephalography, electromyog...

The study of the sleep-wake cycle has been influenced by the works of Soca and von Economo since the early 1900s. Since then, neural circuits of wakefulness and sleep have been identified and described. The neural pathways, nuclei, and neurotransmitters of wakefulness and sleep interact to establish the pathophysiology of normal sleep-wake cycle as...

It is known that auditory information is continuously processed both during wakefulness and sleep. Consistently, it has been shown that sound stimulation mimicking tinnitus during sleep decreases the intensity of tinnitus and improves the patients’ quality of life. The mechanisms underlying this effect are not known. To begin to address this questi...

Men have developed devices in different ways based on sensory stimulation to induce sleep. It is a common experience that the sleep can be facilitated by reducing the amount of afferent sensory information to the brain during wakefulness, for example by closing the eyelids, etc. However, the common practices for centuries demonstrate that specific...

Assess the impact of a reduction of tinnitus intensity achieved through sound stimulation during sleep on the improvement in the patients' quality of life. Acoustic stimuli consisted of a highly customized sound that reproduced the spectral and intensity characteristics of the tinnitus in each patient. This stimulus was uploaded into a portable ele...

Based on the knowledge that sensory processing continues during sleep and that a relationship exists between sleep and learning, a new strategy for treatment of idiopathic subjective tinnitus, consisted of customized sound stimulation presented during sleep, was tested. It has been previously shown that this treatment induces a sustained decrease i...

Achyrocline satureioides (As) (known as Marcela) is a plant belonging to the family Asteraceae, with a high content of flavonoids, which justifies its antioxidant and anti-inflammatory properties. Previous clinical studies confirm that compounds with these actions have beneficial effects on patients with Obstructive Sleep Apnea Syndrome (OSAS). Thi...

The main concepts presented in this review are that sleep is not a function but a state diverse from the waking one. A lot of phy-siologic functions are carried out during sleep, cardiovascular, res-piratory, endocrine, sensory, etc., although in a different way. This state occurs because there is a shifts in all/some cell assemblies -neuronal netw...

Abstract There is scarce information on the global situation of Latin American Sleep Medicine. In the XII Congress of the Federation of Latin American Sleep Societies and the First Congress of the Peruvian Association of Sleep Medicine held in Lima, Peru, in October 2008, a meeting of representatives from different countries of Latin America was or...

To properly demonstrate the effect of auditory input on sleep of intra-cochlear-implanted patients, the following approach was developed. Four implanted deaf patients were recorded during four nights: two nights with the implant OFF, with no auditory input, and two nights with the implant ON, that is, with normal auditory input, being only the comm...

Auditory system neuronal networks may change on passing from wakefulness to sleep stages, therefore, the sleeping brain can process information in a different fashion that includes networks shifts. The auditory unit phase/locking to hippocampus theta rhythm and the firing shifts on passing to the sleep stages, are the processing representative exam...

A new strategy for idiopathic subjective tinnitus treatment – sound stimulation during sleep – has been applied. It was based on the knowledgement that the auditory system also works during sleep, processing the incoming information. Eleven patients were stimulated every night during 6 months. The stimulus was a sound that mimetized the tinnitus an...

A new strategy for idiopathic subjective tinnitus treatment - sound stimulation during sleep - has been applied. It was based on the acknowledgement that the auditory system also works during sleep, processing the incoming information. Eleven patients were stimulated every night during 6 months. The stimulus was a sound that mimetized the tinnitus...

The hippocampal theta rhythm is associated with the processing of sensory systems such as touch, smell, vision and hearing, as well as with motor activity, the modulation of autonomic processes such as cardiac rhythm, and learning and memory processes. The discovery of temporal correlation (phase locking) between the theta rhythm and both visual an...

Brain stem autonomic oscillators, hypothalamic and cortico-frontal centre, entrained by baroreceptor input, have been proposed as the control system of the heart rhythm. Recent reported results in animals suggested that the hippocampal theta waves might also participate as a heart rate modulator. A temporal correlation among the firing of neurons i...

Various rhythms have been shown to affect sensory processing such as the waking-sleep cycle and the hippocampal theta waves. Changes in the firing of visual lateral geniculate nucleus neurons have been reported to be dependent on the animal's behavioral state. The lateral geniculate extracellular neuronal firing and hippocampal field activity were...

The sensory information that the central nervous system receives represents an enormous amount of data coming from the outer world and from the body itself. This constitutes a set of influences that affects the general brain developing as well as on the sleep-waking organization. We have proposed changes in the auditory information processing throu...

Introduction: Neuronal activity of sensory systems depends on input from the environment, the body and the brain itself. Various rhythms have been shown to affect sensory processing, such as the waking-sleep cycle and hippocampal theta waves, our aim in this revision. The hippocampus, known as a structure involved in learning and memory processing...

These experiments were designed to investigate the effect of noise, sleep, and gentamicin on the cochlear microphonic (CM) of the guinea pigs. Are the changes observed due to intrinsic cochlear phenomena or to efferent system actions? To answer this question, noise exposure together with efferent system blockade by gentamicin administration was per...

The aim of the present report was to determine whether or not the heart rate could show any relation to a central electrographic rhythm such as hippocampus theta. Our experimental design included anesthetized as well as chronically implanted guinea pigs. The cross-correlation, spike trigger averaging, between the medullary neurons firing, or the R-...

1. The present review analyzes sensory processing during sleep and wakefulness from a single neuronal viewpoint. Our premises are that processing changes throughout the sleep-wakefulness cycle may be at least partially evidenced in single neurons by (a) changes in the phase locking of the response to the hippocampal theta rhythm, (b) changes in the...

The contribution of N-methyl-D-aspartate to the response to sound of guinea pig inferior colliculus neurons was analyzed by recording single-unit activity before and after iontophoretic injection of a receptor specific antagonist, 2-amino-5-phosphonovaleric acid (AP5), during the sleep-waking cycle. The AP5 produced a significant firing decrease in...

The hippocampal theta rhythm (theta) was reported to be associated with movements, attention, auditory processing, autonomic functions, learning and memory and postulated as an associator of discontiguous events. Since visual information includes temporal cues, our study was centered on the correlation between hippocampal theta rhythm and lateral g...

A physiological approach to the understanding of the central nervous system auditory processing during behavior requires taking into account the mechanisms of perception, attention and sleep/wakefulness generation. The correlation of the neuronal discharge with the hippocampal theta rhythm has been described for motor and sensory modalities. In thi...

To assess to what extent auditory sensory deprivation affects biological rhythmicity, sleep/wakefulness cycle and 24 h rhythm in locomotor activity were examined in golden hamsters after bilateral cochlear lesion. An increase in total sleep time as well as a decrease in wakefulness (W) were associated to an augmented number of W episodes, as well a...

To the best of our knowledge, there is no simple way to induce neural networks to shift from waking mode into sleeping mode. Our best guess is that a whole group of neurons would be involved and that the process would develop in a period of time and a sequence which are mostly unknown. The quasi-total sensory deprivation elicits a new behavioral st...

Several points of interaction exist between sensory inputs and biological rhythms. It was proposed that sensory neuronal activity is a changing phenomenon whose variation is dependent on the interaction of, at least, three signals or sets of signals: a) the specific sensory incoming information; b) the actual behavioral state of the brain; and c) t...

Episodes of heart arrhythmia are present during paradoxical sleep, a known non-homeostatic--'open loop'--physiological state, while wakefulness and slow wave sleep exhibit 'closed-loop' control. A brain-stem autonomic oscillator, a hypothalamic and a corticofrontal center, entrained by baroreceptor input, has been proposed as the main heart rhythm...

Five postlingually deaf patients (age range 28-58 years) with multichannel cochlear implants were examined with single photon emission tomography (SPECT) (triple-head rotating gamma camera). Changes in the regional cerebral blood flow (rCBF) after intravenous administration of technetium-99m ethyl cysteinate dimer (Tc-99m ECD) were assessed through...

Differential actions on inferior colliculus central nucleus (ICc) single cells spontaneous activity were observed with both ipsilateral and contralateral auditory cortical electrical stimulation (ACx stimulation). Following ACx stimulation, a firing depression of the spontaneous activity was obtained using contralateral or ipsilateral cortical stim...

The lateral septum receives the most important afferents from the hippocampus, has been proposed to contribute to theta (θ) rhythm generation. Our aim was to study the membrane and circuital properties of lateral septum neurons and their relationship with hippocampal rhythms. Extra- and intracellular recordings (n=81) were obtained in urethane-anes...

Intracellular in vivo recordings of physiologically identified inferior colliculus central nucleus (ICc) auditory neurons (n=71) were carried out in anesthetized guinea pigs. The neuronal membrane characteristics are described showing mainly quantitative differences with a previous report [Nelson, P.G. and Erulkar, S.D., J. Neurophysiol., 26 (1963)...

After destruction of both cochleae, a significant enhancement of both paradoxical sleep and slow wave sleep together with decreased wakefulness, were observed for up to 45 days. The sleep augmentation consisted of an increment in the number of episodes of both slow wave and paradoxical sleep rather than in the duration of single episodes. The parti...

The activity of 52 single auditory units in the central nucleus of the inferior colliculus (IC) was recorded along with cortical and hippocampal (CA1) electrograms and neck muscle electromyograms in behaving, head-restrained guinea pigs during paradoxical sleep (PS) and wakefulness. Sixteen (30%) of the IC auditory units showed positive correlation...

Intracellular recordings of identified inferior colliculus (ICc) auditory neurons, were analyzed in in vivo awake, chronically implanted guinea-pigs. The passive membrane characteristics as well as the spontaneous and click evoked synaptic potentials and spike activity, were studied. The injection of current pulses revealed little, if any, adaptati...

Transmembrane potentials from medial septal and diagonal band of Broca (MS-DBB) neurons and hippocampal field activity were recorded in curarized and urethanized rats. MS-DBB cells were studied during large amplitude irregular activity and during hippocampal theta rhythm, elicited by either sensory (i.e. stroking the fur on the animal's back) or el...

The existence region of two-tone rate suppression in frog low-frequency auditory-nerve fibers was found to include a suppressive region below a fiber's characteristic frequency, contrary to previous reports. In response to 3 degrees C rise in core temperature, the area and the best suppressive frequency (BSF) of the low-side suppressive region sign...

The effects of behavioral shifts on auditory lateral superior olive neurons were analyzed in guinea-pigs during the sleep-waking cycle with single unit extracellular recordings at the unit characteristic frequency and with low sound intensity. Shifts in the number of spikes in response to pure tones and in spontaneous firing proved to be closely re...

The body generates many physiological sounds. One of the most prominent is that produced by the blood flowing inside the vessels with each heart beat. On the other hand, the cochlea is a very sensitive receptor with a low threshold. Given the anatomical close proximity of the carotid artery and other vessels to the inner ear, the possibility of its...

The effects of waking and sleep on the response properties of auditory units in the ventral cochlear nucleus (CN) were explored by using extracellular recordings in chronic guinea-pigs. Significant increases and decreases in firing rate were detected in two neuronal groups, a) the "sound-responding" and b) the "spontaneous" (units that do not show...

Horseradish peroxidase placed into the ventral mesencephalic periaqueductal gray (PAG) and in the lateral superior olivary complex region demonstrated indirect paths towards the cochlear nucleus (CN). Because no direct connections could be observed, a pathway throughout the auditory efferent system was proposed. The results suggest three possibilit...

The effect of periaqueductal gray (PAG) electrical stimulation on the response properties of auditory and ‘spontaneously’ firing units (abolished when the cochlea is destroyed) in the anteroventral cochlear nucleus (AVCN) was explored using extracellular recordings in acute guinea-pigs. Significant increases and decreases in firing rate were detect...

Gross cochlear potentials in response to alternating clicks and pure tone bursts were recorded in guinea-pigs with chronically implanted electrodes in the round window during sleep and the awake state. A significant increase in both averaged potentials, the compound auditory nerve action potential (cAP) and cochlear microphonics (CM) occurred in sl...

The influence exerted by chlordiazepoxide or midazolam upon auditory nerve compound action potential (cAP) and cochlear microphonic (CM) has been analyzed in chronic as well as in acutely prepared guinea pigs. Pre-receptorial variables were carefully controlled. The benzodiazepines dissociated the conchlear recroded potentials, increasing the cAP a...