Inactivation of the Tuberomammillary Nucleus by GABAA Receptor Agonist Promotes Slow Wave Sleep in Freely Moving Rats and Histamine-Treated Rats.

In this study, alterations of sleep-wake states and cortical EEG power spectral density were investigated following muscimol, a GABAA-receptor agonist, microinjected bilaterally into the TMN in freely moving rats and HA pretreated rats, respectively. Muscimol dosed at 0.25 and 0.50 μg/side into the TMN during dark period dose-dependently increased slow wave sleep (SWS) accompanied by an increase in cortical EEG delta (0.5-4 Hz) and spindle (8.2-12 Hz) activities. In the meanwhile, wakefulness and EEG beta (12.2-30 Hz) activity were decreased significantly, while paradoxical sleep and EEG theta (4.2-8 Hz) activity were not changed. The increase of muscimol-induced SWS was because of prolonged SWS bout duration and not to an increased bout number. Muscimol (0.50 μg/side) administration 2 h after HA (0.125 μg/side) treatment during light period reversed the HA-induced wakefulness and EEG beta 2 (20.2-30 Hz) activity into SWS and EEG delta activity. These results demonstrate that the GABAergic inactivation of the TMN in freely moving rats and HA-treated rats promotes SWS and slow activity of cortical EEG, suggesting that the potential function of the GABAA receptor in the TMN is to dampen vigilant arousal. PMID: 28365867 [PubMed - as supplied by publisher]
Source: Neurochemical Research - Category: Neuroscience Authors: Tags: Neurochem Res Source Type: research