Preoptic area sleep-regulating mechanisms.
Evidence is summarized for the existence of a sleep-regulating mechanism within the preoptic area of the hypothalamus, including the results of lesion, stimulation, and neuronal recording studies. Recent findings employing the c-fos protein immunohistochemical method, have localized putative sleep-regulatory neurons to the ventrolateral preoptic area (vlPOA) and the median preoptic nucleus (MnPn). Electrophysiological studies have confirmed the presence of neurons with sleep-related discharge in the vlPOA. Neurons in the vlPOA that exhibit c-fos protein immunoreactivity during sleep contain the inhibitory neuromodulators galanin and gamma-aminobutyric acid (GABA). These neurons also project to monoaminergic arousal systems, particularly the histaminergic cell groups in the posterior hypothalamus. POA neurons can be hypothesized to provide sleep-related inhibitory control over multiple arousal systems in the forebrain and brainstem.
Research Service (151A3), V.A. Greater Los Angeles Healthcare System, Departments of Medicine and Psychology, University of California, Los Angeles, USA.
R
R
Szymusiak
T
T
Steininger
N
N
Alam
D
D
McGinty
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D007025:Anterior Hypothalamic Nucleus / Q000166:cytology / Q000502:physiology; D020532:Basal Nucleus of Meynert / Q000166:cytology / Q000502:physiology; D001933:Brain Stem / Q000166:cytology / Q000502:physiology; D006801:Humans; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D011301:Preoptic Area / Q000166:cytology / Q000502:physiology*; D012890:Sleep / Q000502:physiology*