Effects of microinjection of 5-hydroxytryptophane and methysergide in the ventrolateral preoptic nucleus on sleep-waking cycle
Zhang Gongliang, Zhao Lezhang, Zhang Jin et al (Dept of Physiology , Anhui Medical University, Hefei 230032)
Objective To study the effects of serotonin (5 HT) in ventrolateral preoptic nucleus(VLPO) on sleep and waking cycle. Methods Stereotaxic,microinjection and polysomnography (PSG) were used in the experiment. Results Microinjection of 5 hydroxytryptaphan (5 HTP, precursor of 5 HT) into the VLPO increased waking time, and decreased slow wave sleep (SWS) and paradoxical sleep (PS) times, while microinjection of non selective serotonin receptor antagonist methysergide (MS) produced the contrary effects. Conclusion 5 HT is involved in the regulation of sleep waking cycle and promotes wakefulness in the VLPO.