Influence of a GABAB and GABAC receptor antagonist on sleep–waking cycle in the rat

This study tested the influence of CGP 36742, a both gamma-aminobutyric acidB (GABAB) and GABAC receptor antagonist, on sleep and waking. The compound was injected intraperitoneally at 1, 10, 30, 100, 300 and 500 mg/kg to rats which were recorded during 6 h. Only at 500 mg/kg, total waking was increased during third and fourth hours and total duration of recording by a specific enhancement of quiet waking (without hippocampal theta activity). Slow wave sleep was decreased at 100, 300, 500 mg/kg during the third and fourth hours, and during total recording time at 500 mg/kg. Paradoxical sleep was not affected. While it was not possible to distinguish already known GABAB and GABAC identical influence on waking and slow wave sleep, their previously shown opposite effect on paradoxical sleep seemed to nullify each other.