Sleep is differently modulated by basal forebrain GABA A and GABA B receptors

• Published in: American journal of physiology. Regulatory, integrative and comparative physiology integrative and comparative physiology, 2001-07, Vol.281 (1), p.R170-R175
• Main Authors: Manfridi, Alfredo, Brambilla, Dario, Mancia, Mauro
• Format: Article
• Language: English
• ISSN: 0363-6119; 1522-1490
• DOI: 10.1152/ajpregu.2001.281.1.R170

There is evidence that GABA plays a major role in sleep regulation. GABA A receptor agonists and different compounds interacting with the GABA A receptor complex, such as barbiturates and benzodiazepines, can interfere with the sleep/wake cycle. On the other hand, there is very little information about the possible role of GABA B receptors in sleep modulation. The nucleus basalis of Meynert (NBM), a cholinergic area in the basal forebrain, plays a pivotal role in the modulation of sleep and wakefulness, and both GABA A and GABA B receptors have been described within the NBM. This study used unilateral infusions in the NBM to determine the effects of 3-hydroxy-5-aminomethylisoxazole hydrobromide (muscimol hydrobromide, a GABA A receptor subtype agonist) and β-(aminomethyl)-4-chlorobenzenepropanoic acid (baclofen, a GABA B receptor subtype agonist) on sleep parameters in freely moving rats by means of polygraphic recordings. Muscimol (0.5 nmol) and baclofen (0.7 nmol) induced an increase in slow-wave sleep and an inhibition of wakefulness. Muscimol, but not baclofen, also caused a decrease in desynchronized sleep parameters. The results reported here indicate that 1) the NBM activation of both GABA A and GABA B receptors influences the sleep/wake cycle, and 2) GABA A but not GABA B receptors are important for desynchronized sleep modulation, suggesting that the two GABAergic receptors play different roles in sleep modulation.