This notion is supported by neuroimaging studies that showed more precise encoding of sounds in the brainstem of musicians compared with non-musicians e. Interestingly, individuals with more musical training exhibit better encoding of speech sounds in the brainstem, larger cortical responses, and better speech sound perception Strait and Kraus, ; Strait et al. Although the role of the cerebellum for speech and music perception is not mentioned in the OPERA hypothesis, we also include the cerebellum as a part of the auditory afferent circuit because it receives input from the cochlear nuclei Huang et al.
In addition, musicians showed enhanced activity in the cerebellum compared to non-musicians during temporal perception Lu et al. Rhythm perception or sound envelope processing in music may engage neural activities in the subcortical—prefrontal circuit relevant for emotional processing. A primate study has shown that rhythmic drumming sounds serve as communicative signals and engage the emotional network in the subcortical areas including the amygdala and the putamen Remedios et al. Human neuroimaging studies have shown that listening to music elicit pleasant emotion by engaging the reward system in the subcortical and cortical areas including the midbrain e.
Recent behavioral studies have also shown that listening to musical rhythm elicits positive affect and a desire to move Zentner and Eerola, ; Witek et al. Similarly, perception of poetry in the presence of rhyme and regular meter lead to enhanced positive emotions, suggesting that perceiving rhythmic vocalizations may result in positive emotions Obermeier et al. Synchronization and entrainment to a pulse in music may place high demands on information process in the BG-thalamo-cortical circuit.
This notion is based on the fact that musical rhythm is more periodic while speech rhythm is quasi-periodic Peelle and Davis, Compared with speech rhythm, musical rhythm has a more salient pulse- or beat-based timing. Neuroimaging studies suggest that perception of beat-based timing i. Animal studies also suggest the importance of brain networks involving the BG and cortical auditory-motor areas for beat perception and synchronization capabilities Patel et al.
In addition, tapping to a beat is associated with increased cortical responses in the DLPFC and the inferior parietal lobule Chen et al. This attention-related brain network has been shown to be more engaged in precise synchronization performance with the musical beat Chen et al.
Not only vocalizations but also other body movements can be synchronized and entrained to the pulse of music, such as tapping, clapping, stepping, dancing, and singing. In terms of the motor-output process in the brain, involvements of both the dorsal and ventral portions of the M1, PMC, and PFC are likely. Neuroimaging studies have shown that cortical hand motor areas are involved not only in hand motor control but also in language processing e.
In addition, a recent transcranial magnetic stimulation TMS study has shown that listening to groove music modulates cortico-spinal excitability Stupacher et al. In sum, there are four circuits of interest in the SEP hypothesis, which may help to stimulate the brain networks underlying human communication. The SEP hypothesis postulates that rhythm-based therapy elicits functional and structural reorganization in the neural networks for human communication in various patient populations via sound envelope processing and synchronization and entrainment to a pulse.
In this section, we present examples of speech and language disorders and consider the role of rhythm in speech and language rehabilitation under the framework of the SEP hypothesis. We note, however, that the number of rhythm-based techniques currently available is very limited. In addition to the more commonly known symptoms such as muscular rigidity, tremor, and postural instability, abnormalities of voice and speech beyond those associated with aging are highly prevalent.
Examples of deficits reported by clinicians include monopitch, monoloudness, hypokinetic articulation, and altered speech rate and rhythm Darley et al. Analysis of the speech rate of patients with PD showed impaired rhythm and timing organization, such as an accelerated rate of articulation during speaking, as well as a reduction in the total number of pauses Skodda and Schlegel, ; Skodda et al.
When combined with the debilitating motor limb deficits, the loss of speech intelligibility and communication skills can significantly impair the quality of life of patients with PD Streifler and Hofman, These studies must be interpreted with caution because the results vary depending on treatment status of patients with PD.
For example, patients with PD with no medication and no deep brain stimulation showed significant dysarthria accompanying with a lack of activity in the orfacial motor cortex M1 and cerebellum while increased activities in the PMC, SMA, and DLPFC compared with the healthy controls Pinto et al. These abnormal cortical activities disappeared and the dysarthria symptoms improved after the deep brain stimulation of subthalamic nucleus STN in these patients Pinto et al.
Compared to healthy controls, patients with PD with the levodopa medication had increased activity in the orofacial sensorimotor cortex Rektorova et al. However, speech productions in these patients with PD with levodopa medication was comparable with that in the controls except for speech loudness, suggesting that the increased brain activity and connectivity might reflect the effects of pharmacological treatment or successful compensatory mechanisms Rektorova et al. Besides the deep brain stimulation and pharmacological treatments, Lee Silverman Voice Treatment LSVT technique has received research attention as a rehabilitation method Ramig et al.
LSVT is designed to improve vocal function in patients with PD by enhancing loudness, intonation range, and articulatory functions. LSVT emphasizes use of loud phonation and high intensity vocal exercises to improve respiratory, laryngeal, and articulatory during speech. Compared with placebo therapy, LSVT has resulted in improvements in speech production parameters such as increases in sound pressure level i.
Under the SEP hypothesis, patients with PD can benefit from synchronization and entrainment to a pulse in music to stimulate the subcortical—prefrontal network and the BG-thalamo-cortical network. Blue arrows indicate inhibitory projections, while red arrows indicate excitatory projections. Changes in the thickness of the arrows indicate increase thicker arrow or decrease thinner arrow of the projections relative to the normal situation.
Light blue, green, and yellow colors denote BG, thalamus, and cortex, respectively. D1 and D2 indicate subtypes of dopamine receptor. This is based on a previous study, which showed an increase in dopamine release and hemodynamic response in the striatum during listening pleasurable music Salimpoor et al. This idea is also supported by the other studies that showed modulation in the cortico-spinal excitability Stupacher et al.
Indeed, a number of studies have shown improvements of motor function in patients with PD during rhythmic auditory stimulation RAS e. However, there remain a few untested assumptions. For example, patients with PD show impaired emotional recognition in music e. Therefore, dopamine release in the striatum may not be increased by music in patients with PD as seen in healthy individuals. Positron emission tomography PET can be used to test this hypothesis Laruelle, ; Salimpoor et al.
A recent study has shown improved perceptual and motor timing in patients with PD after a 4-week music training program with rhythmic auditory cueing Benoit et al. However, the participants of that study consisted only of mild to moderate patients with PD Benoit et al. Future studies will need to clarify whether the RAS is also beneficial for severe patients with PD, and how the therapeutic effect is different. It may also be important to test whether RAS simple metronome stimulation as well as rhythmic musical stimulation improves speech function in patients with PD, given gait functions have been a topic of research interest e.
Stuttering is a developmental condition that affects fluency of speech. Symptoms include repetition of words or parts of words, as well as prolongations of speech sounds, resulting in disruptions in the normal flow of speech. In addition, stuttering is associated with reduced activity and connectivity in the brain network including the BG and the SMA e. To date, examples of fluency shaping methods for stuttering include altered auditory feedback e.
The altered auditory feedback methods are considered to be effective to change the excessive reliance on auditory feedback control, while the other speech production trainings would help to reform feed-forward speech commands. Yet, a therapy that focuses specifically on stimulating the BG-thalamo-cortical circuit to enhance rhythmic speech production would also be warranted Alm, The SEP hypothesis assumes that individuals who stutter may benefit from rhythm-based therapy using synchronization and entrainment to a pulse for stimulating the BG-thalamo-cortical circuit.
Behavioral studies support this notion by showing that the presence of rhythmic auditory signals such as metronome beats, when synchronized with speech production, induces strong fluency-enhancing effects in individuals who stutter e. A recent fMRI study also supports this notion by showing that BG activities of stuttering speakers increased to the level of normal speech controls when speaking with the metronome beats Toyomura et al. Nevertheless, given that stuttering is a relapse-prone disorder Craig, , long-term management strategies are likely to be useful when dealing with this disorder over a lifetime.
Accordingly, future studies need to test how long the metronome-induced fluency sustains after removing the rhythmic sounds.
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It has been suggested that the BG-thalamo-SMA circuit is dominant for self-initiation of speech, while the PMC-thalamo-cerebellar circuit is dominant for externally cued speech Alm, Therefore, one of the challenges for future studies is to transition from the externally cued PMC-centered speech to self-initiated SMA-centered speech in the treatments using metronome-guided cues. To engage the BG-thalamo-SMA circuit, it may be useful to use non-isochronous metronome stimuli to promote the patients to find a pulse and initiate rhythmic speech by themselves.
In addition, future studies need to test whether structural and functional reorganization occur in the BG-thalamo-cortical circuit after the intervention using the rhythmic auditory cues. Concurrently, more basic studies are needed to clarify whether the neural underpinnings of stuttering overlap with those of rhythm processing in music. Investigations of the abilities of musical rhythm processing in individuals who stutter using an amusia battery e.
In addition, there is a need to test whether synchronization to a pulse in music have the similar fluency-enhancing effect for stuttering speakers compared with the synchronization to a metronome. Aphasia is a common and devastating consequence of stroke or other brain injuries that results in language-related dysfunction. Many patients with large left hemisphere lesions have poor prognosis, despite having received years of intensive speech therapy Lazar et al. However, emerging evidence suggests that some techniques have the potential to improve the verbal communication skills of these patients, as well as to reorganize the underlying neural processes related to language.
For example, inspired by the clinical observation that patients with non-fluent aphasia can sing words even though they are unable to speak Gerstmann, ; Yamadori et al. The main components of this speech therapy technique are 1 melodic intonation, 2 the use of formulaic phrases and sentences, and 3 slow and periodic verbalization with left-hand tapping Schlaug et al.
The Role of Rhythm in Speech and Language Rehabilitation: The SEP Hypothesis
Emerging evidence involving open-label studies has revealed some positive treatment effects Wilson et al. The contribution of singing is supported by the neuroimaging findings of right hemisphere lateralization of singing processing when compared to speaking e. However, it is important to note that the latter studies often included patients with very large lesions that sometimes cover most of the left hemisphere, thus precluding analysis of language-related areas within that hemisphere. Recent studies have highlighted the potential role of rhythm in aphasia treatment.
For example, aphasia recovery, as denoted by correct syllable production, was examined by comparing singing therapy, rhythmic therapy, and standard speech therapy Stahl et al. The results showed that, when compared to singing therapy, the rhythmic therapy was similarly effective Stahl et al. Moreover, patients with lesions that cover the BG were found to be highly dependent on the external rhythmic cues Stahl et al. Taken together, this study highlights the role of rhythm in aphasia recovery.
The SEP hypothesis postulates that the rhythmic components e. That is, the predictability of formulaic phrases and sentences requires precise encoding of pulse or periodic timing of vocalizations, while left-hand tapping can facilitate synchronization and entrainment to the pulse. A rationale for MIT is the potential to engage and unmask language-capable regions in the unaffected right hemisphere such as the structural reorganization of arcuate fasciculus, a fiber bundle connecting the posterior superior temporal region and the posterior inferior frontal region Schlaug et al.
If MIT engages high demands on the right temporal cortex to encode sound envelope precisely, it may also increase the connectivity from the right temporal cortex to the right inferior frontal gyrus IFG. Importantly, rhythmic therapy in aphasia patients with left basal ganglia lesion resulted in improved production of common formulaic phrases that are known to be supported by right BG-thalamo-cortical network Stahl et al.
The left-hand tapping in MIT might be also interpreted as a way to recruit enlarged involvement of contralateral right motor areas i. One of the core features of autism spectrum disorder ASD is impairment in language and communication. For children with ASD, the ability to speak early is associated with improved quality of life.
Research has reported the presence of motor and oral-motor impairments in ASD children who have expressive language deficits Belmonte et al. To date, very few interventions have specifically targeted the oral-motor aspects in ASD. Another therapy technique that incorporates a motor component is auditory-motor mapping training AMMT , which is an active multisensory therapy designed to facilitate speech output in completely non-verbal children with autism Wan et al.
This technique aims to promote speech production directly by training the association between speech sounds and articulatory actions using slow and melodic intonating vocalizations with bimanual motor activities Wan et al. An initial proof-of-concept study indicated the therapeutic potential of AMMT in facilitating speech development in autism Wan et al.
The former relates to intoned vocalizations, and the latter relates to spoken syllables being linked with the bimanual motor actions on the tuned drums. First, perception of rhythmic drumming and vocal sounds may stimulate the auditory afferent circuit for the precise encoding of sound envelope or temporal events.
Indeed, it has been shown that ASD is associated with developmental abnormalities in the brainstem and cerebellum in utero , which can lead to abnormal timing and sensory perception in ASD Trevarthen and Delafield-Butt, Second, synchronization and entrainment of rhythmic vocalizations and bimanual motor actions may be effective to stimulate the speech motor and language networks in ASD. In this paper, we consider the role of rhythm in speech and language rehabilitation.
The emerging research field of music and neuroscience led us to propose the SEP hypothesis, which postulates that 1 sound envelope processing and 2 synchronization and entrainment to a pulse, may help to stimulate brain networks for human communication. Within the SEP framework, we present four possible circuits that may help to stimulate the brain networks underlying human communication: We hope that future studies combining neuroimaging techniques and randomized control designs with the SEP framework will help to evaluate the efficacy of the rhythm-based therapies.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. National Center for Biotechnology Information , U. Journal List Front Hum Neurosci v. Published online Oct Author information Article notes Copyright and License information Disclaimer.
Received Jul 3; Accepted Sep The use, distribution or reproduction in other forums is permitted, provided the original author s or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. This article has been cited by other articles in PMC. Abstract For thousands of years, human beings have engaged in rhythmic activities such as drumming, dancing, and singing. Introduction Human beings have universally engaged in rhythmic musical activities such as drumming, dancing, singing, and playing musical instruments since ancient times e.
Rhythm as a Medium of Communication Rhythm, or the temporal organization of perceived or produced events, mediates communication and social interaction.
CIRCADIAN RHYTHM DISTURBANCES IN DEPRESSION
The Role of Rhythm in Speech Rhythm is essential to the understanding of speech. Open in a separate window. Neural Correlates of Rhythmic Speech Perception A question arises then, regarding how rhythm or sound envelope is processed in the brain. Neural Correlates of Rhythmic Speech Production In the previous section, we described the neural correlates of sound envelope or rhythm processing in speech perception.
Auditory afferent circuit According to the OPERA hypothesis, musical activities place high demands on precise encoding of acoustic features including the sound envelope Patel, , , Subcortical—prefrontal circuit Rhythm perception or sound envelope processing in music may engage neural activities in the subcortical—prefrontal circuit relevant for emotional processing. BG-thalamo-cortical circuit Synchronization and entrainment to a pulse in music may place high demands on information process in the BG-thalamo-cortical circuit.
Stuttering Stuttering is a developmental condition that affects fluency of speech. Aphasia Aphasia is a common and devastating consequence of stroke or other brain injuries that results in language-related dysfunction. Autism One of the core features of autism spectrum disorder ASD is impairment in language and communication.
Conclusion In this paper, we consider the role of rhythm in speech and language rehabilitation. Conflict of Interest Statement The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Right-hemisphere auditory cortex is dominant for coding syllable patterns in speech. Abnormal cortical processing of the syllable rate of speech in poor readers. Speech comprehension is correlated with temporal response patterns recorded from auditory cortex. Stuttering and the basal ganglia circuits: The effect of SpeechEasy on stuttering frequency, speech rate, and speech naturalness.
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Oral motor deficits in speech-impaired children with autism. Six-month-old infants discriminate voicing on the basis of temporal envelope cues L. Intensely pleasurable responses to music correlate with activity in brain regions implicated in reward and emotion. Two-year outcomes for interpersonal and social rhythm therapy in individuals with bipolar I disorder. The mammalian circadian timing system: Effects of a brief behavioral treatment for late-life insomnia: J Clin Sleep Med.
The hypothalamic suprachiasmatic nuclei: Controlled trial of bright light and negative air ions for chronic depression. Bipolar Disorders and Recurrent Depression. Oxford University Press; New York: A longitudinal study of diurnal mood variation in depression; characteristics and significance. Effects of REM sleep awakenings and related wakening paradigms in the ultradian sleep cycle and the symptoms in depression.
Circadian regulation of diverse gene products revealed by mRNA expression profiling of synchronized fibroblasts. Differential control of peripheral circadian rhythms by suprachiasmatic-dependent neural signals. Temporal and spatial expression patterns of canonical clock genes and clock-controlled genes in the suprachiasmatic nucleus.
Expression of Period genes: Neurotransmitters of the retino-hypothalamic tract. Melanopsin-containing retinal ganglion cells: Circadian rhythms of arginine vasopressin and vasoactive intestinal polypeptide do not depend on cytoarchitecture of dispersed cell culture of rat suprachiasmatic nucleus. Analysis of sleep-wakefulness rhythms in male rats after suprachiasmatic nucleus lesions and ocular enucleation.
Integrative coordination of circadian mammalian diversity: Separate oscillating cell groups in mouse suprachiasmatic nucleus couple photoperiodically to the onset and end of daily activity. Expression of a gene cluster kaiABC as a circadian feedback process in cyanobacteria. Circadian clock-related polymorphisms in seasonal affective disorder and their relevance to diurnal preference. Reversed diurnal variation in depression: Melatonin secretion in SAD patients and healthy subjects matched with respect to age and sex.
Int J Circumpolar Health.
Positional cloning of the mouse circadian clock gene. Clock mutants of Drosophila melanogaster. The effects of electroconvulsive therapy on melatonin. Early evening melatonin and S advance circadian phase and nocturnal regulation of core body temperature. Phase-advance theories for affective illness. Circadian Rhythms in Psychiatry. Sleep and treatment prediction in endogenous depression. Pathophysiology of seasonal affective disorder: Clinical and Academic Publishing; Canada: Melatonin suppression in bipolar and unipolar mood disorders. Effects of light therapy on suicidal ideation in patients with winter depression.
Increased suicide rate in the middle-aged and its association with hours of sunlight. Phase-shifts of h rhythms of hormonal release and body temperature following early evening administration of the melatonin agonist agomelatine in healthy older men. Clin Endocrinol Oxf ; The chronobiology and neurobiology of winter seasonal affective disorder. The dim light melatonin onset, melatonin assays and biological rhythm research in humans. Morning vs evening light treatment of patients with winter depression.
Circadian uses of melatonin in humans. Melatonin entrains free-running blind people according to a physiological dose-response curve. The phase shift hypothesis for the circadian component of winter depression. Antidepressant and circadian phase-shifting effects of light. Manic-depressive patients may be supersensitive to light. The sleep disorder canine narcolepsy is caused by a mutation in the hypocretin orexin receptor 2 gene.
Molecular cloning of genes under control of the circadian clock in Neurospora. Bright light treatment of depression for older adults. Bright light augments antidepressant effects of medication and wake therapy. Contrasting effects of ibotenate lesions of the paraventricular nucleus and subparaventricular zone on sleep-wake cycle and temperature regulation.
Body temperature in endogenously depressed patients during depression and remission. Circadian rhythms in psychiatry. Human pineal physiology and functional significance of melatonin. The diagnosis, symptomatology, and epidemiology of seasonal affective disorder. Relationship between insomnia, depression, and mortality: Entrainment of circadian rhythms by S, a melatonin agonist, is dose and plasma concentration dependent. Control mechanism of the circadian clock for timing of cell division in vivo. Synchronization and maintenance of timekeeping in suprachiasmatic circadian clock cells by neuropeptidergic signaling.
The novel melatonin agonist agomelatine S is an antagonist at 5-hydroxytryptamine2C receptors, blockade of which enhances the activity of frontocortical dopaminergic and adrenergic pathways. J Pharmacol Exp Ther. Circadian rhythms during and after three months in solitude underground.
The circadian rhythms of human subjects without timepieces or indication of the alternation of day and night. Activation of NMDA receptors in the suprachiasmatic nucleus produces light-like phase shifts of the circadian clock in vivo. Organization of neural inputs to the suprachiasmatic nucleus in the rat. Nocturnal and circadian body temperatures of depressed outpatients during symptomatic and recovered states. Regularity of daily life in relation to personality, age, gender, sleep quality and circadian rhythms.
Paraventricular-subparaventricular hypothalamic lesions selectively affect circadian function.
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Loss of circadian adrenal corticosterone rhythm following suprachiasmatic lesions in the rat. Serotonin innervation of the primate suprachiasmatic nucleus. Long-term cultured neurons from rat suprachiasmatic nucleus retain the capacity for circadian oscillation of vasopressin release.
Functional analysis of the role of the median raphe as a regulator of hamster circadian system sensitivity to light. Circadian gene expression in individual fibroblasts: The role of suprachiasmatic nuclei of the hypothalamus in the production of circadian rhythm. Melatonin suppession by light in euthymic bipolar and unipolar patients. Place of chronic insomnia in the course of depressive and anxiety disorders. Cortisol responses to daily events in major depressive disorder. Levels and variability of daily life cortisol secretion in major depression.
Self-reported sleep disturbance as a prodromal symptom in recurrent depression. Suprachiasmatic control of melatonin synthesis in rats: Independent photoreceptive circadian clocks throughout Drosophila. Stressful life events, social rhythms, and depressive symptoms among the elderly: An examination of hypothesized causal linkages. Serotonin phase-shifts the mouse suprachiasmatic circadian clock in vitro.
The biological clock nucleus: Diurnal profile of melatonin secretion in the acute phase of major depression and in remission. Transplanted suprachiasmatic nucleus determines circadian period. Molecular analysis of the period locus in Drosophila melanogaster and identification of a transcript involved in biological rhythms. Entrainment of rat circadian rhythms by the melatonin agonist S requires intact suprachiasmatic nuclei but not the pineal. Sleep and depression — results from psychobiological studies: Sleep complaints and depression in an aging cohort: Molecular genetics of the fruit-fly circadian clock.
Eur J Hum Genet. Treatment of Psychiatric Disorders, Volume 1. Reduced REM latency predicts response to tricyclic medication in depressed outpatients. Entrainment of free-running circadian rhythms by melatonin in blind people.
N Engl J Med. Orexins and orexin receptors: Hypothalamic regulation of sleep and circadian rhythms. Transplantation of the neonatal suprachiasmatic nuclei into rats with complete bilateral suprachiasmatic lesions. Peripheral circadian oscillators in mammals: Genetic dissection of psychopathological symptoms: Pharmacogenetics of selective serotonin reuptake inhibitor response: The neurobiology of depression: Effect of pharmacologic treatments on the sleep of depressed patients.
Social rhythm in anxiety disorder patients. Interacting molecular loops in the mammalian circadian clock. Electrical and metabolic activity of suprachiasmatic neurons in hamster hypothalamic slices. Central visual pathways and the distribution of sleep in h and 1-hr light-dark cycles.
Serotonergic modulation of retinal input to the mouse suprachiasmatic nucleus mediated by 5-HT 1B and 5-HT 7 receptors. Restoration of circadian behavior by anterior hypothalamic heterografts. Circadian rhythms in depression and recovery: Treatment of chronic insomnia by restriction of time in bed. Circadian rhythms in drinking behavior and locomotor activity of rats are eliminated by hypothalamic lesions. Uncoupling of social zeitgebers and diurnal cortisol secretion in clinical depression.
Entrainment of the circadian clock in the liver by feeding. Effect of transplantation of embryonic anterior hypothalamic tissue from spontaneously hypertensive rats to normotensive Wistar rats on circadian rhythms of systolic arterial pressure and heart rate. Acta Physiol Pharmacol Bulg. Bright light treatment decreases depression in institutionalized older adults: Electroconvulsive therapy increases circadian amplitude and lowers core body temperature in depressed subjects.
Disruption of social circadian rhythms in major depression: A pilot study of cognitive-behavioral therapy of insomnia in people with mild depression. Circadian oscillation of a mammalian homologue of the Drosophila period gene. Circadian time of morning light administration and therapeutic response in winter depression. A controlled trial of timed bright light and negative air ionization for treatment of winter depression. Identifying an abnormal electroencephalographic sleep profile to characterize major depressive disorder.
Electroencephalographic sleep in secondary depression: A comparison of melatonin secretion in depressed patients and normal subjects. On the daily rhythm of depression symptomatology. Circadian neural rhythms in mammals. Light therapy for non-seasonal depression. Cochrane Database Syst Rev. Seasonal changes in h patterns of suicide rates: Melatonin or a melatonin agonist corrects age-related changes in circadian response to environmental stimulus. Mutagenesis and mapping of a mouse gene, Clock , essential for circadian behavior.
Evidence for REM sleep deprivation as the mechanism of action of antidepressant drugs. Prog Neuropsychopharmacol Biol Psychiatry. Drug effects on REM sleep and on endogenous depression. Improvement of depression by REM sleep deprivation. Circadian thythms of vasopressin release in primary cultures of rat suprachiasmatic nucleus.
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