Publication Date:
2013-07-12
Description:
The median preoptic nucleus (MnPN) and the ventrolateral preoptic area (VLPO) are two hypothalamic regions that have been implicated in sleep regulation, and both nuclei contain sleep-active GABAergic neurons. Adenosine is an endogenous sleep regulatory substance, which promotes sleep via A 1 and A 2A receptors (A 2A R). Infusion of A 2A R agonist into the lateral ventricle or into the subarachnoid space underlying the rostral basal forebrain (SS-rBF), has been previously shown to increase sleep. We examined the effects of an A 2A R agonist, CGS-21680, administered into the lateral ventricle and the SS-rBF on sleep and c-Fos protein immunoreactivity (Fos-IR) in GABAergic neurons in the MnPN and VLPO. Intracerebroventricular administration of CGS-21680 during the second half of lights-on phase increased sleep and increased the number of MnPN and VLPO GABAergic neurons expressing Fos-IR. Similar effects were found with CGS-21680 microinjection into the SS-rBF. The induction of Fos-IR in preoptic GABAergic neurons was not secondary to drug-induced sleep, since CGS-21680 delivered to the SS-rBF significantly increased Fos-IR in MnPN and VLPO neurons in animals that were not permitted to sleep. Intracerebroventricular infusion of ZM-241385, an A 2A R antagonist, during the last 2 h of a 3-h period of sleep deprivation caused suppression of subsequent recovery sleep and reduced Fos-IR in MnPN and VLPO GABAergic neurons. Our findings support a hypothesis that A 2A R-mediated activation of MnPN and VLPO GABAergic neurons contributes to adenosinergic regulation of sleep.
Print ISSN:
0363-6119
Electronic ISSN:
1522-1490
Topics:
Medicine
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