CHLORAMPHENICOL PREVENTS CARBACHOL-INDUCED REM-SLEEP IN CATS

Twenty-four cats were implanted for chronic sleep recordings.One week after the surgery, cats were divided into four groups. Two groups were treated with three i.p. injections of 150 mg/kg chloramphenicol (CAP) separated by 12 h. Carbachol (8 mug/1mul) or saline (1 mul) was injec ted into the pontine reticular formation (PRF) 1 h after the last inje ction of CAP. The other two groups received saline or carbachol into t he PRF without CAP pre-treatment. Polygraphic recordings were started immediately after the microinjection and lasted 11 h. Carbachol increa sed REM sleep (P < 0.001) and reduced SWS2 (P < 0.05). In contrast, ch loramphenicol reduced REM sleep (P < 0.001) and increased SWS2 (P < 0. 01). The combination of these drugs increased wakefulness (P < 0.01) a nd reduced both SWS2 and REM sleep (P < 0.001). This data shows that c hloramphenicol prevents carbachol induced REM sleep. Results are discu ssed in terms of an interaction between brain proteins and the choline rgic system to induce REM.