Kainic acid lesions of gigantocellular tegmental field (FTG) neurons does not abolish REM sleep

This study attempts to resolve questions concerning the cholinergic mediation of REM sleep by FTG cells. The sleep-wake cycle of cats with bilateral kainic acid destruction of FTG cells, was followed for 2 months. At the end of this period carbachol was applied unilaterally on the lesioned site. The results showed no changes in REM despite the absence of FTG cells. No changes were observed following carbachol administration. This study shows that FTG cells are not essential for REM sleep, but that in non-lesioned cats its cholinergic activation may form part of a complex REM generating system.