ABSTRACT
AIM To investigate the role of serotonergic projection from dorsal raphe nuclei (DRN) to basolateral amygadaloid (BLA) in the regulation of sleep and waking state. METHODS stereotaxic microinjection and polysomnography were employed. RESULTS Microinjection of L Glu into the DRN caused an enhancement of wake (W) and a decrease of slow wave sleep (SWS) and paradoxical sleep (PS). However, microinjection of L Glu into the DRN plus bilateral microinjection of methysergide (MS) into the BLA reversed the effects of L Glu. Microinjection of PCPA into the DRN caused an enhancement of SWS and a decrease of W. Microinjection of PCPA into the DRN plus bilateral microinjection of 5 HTP into the BLA reversed the effects of PCPA. CONCLUSION These results suggest that the role of the DRN in the regulation of sleep and waking state is partly mediated by serotonergic projection from the DRN to the BLA.