CONTRIBUTION OF CENTRAL 5-HT2 RECEPTORS IN THE OCCURRENCE OF LOCOMOTOR-ACTIVITY AND MYOCLONIA IN FREELY MOVING RATS EXPOSED TO HIGH-PRESSURE

HELIUM pressure of more than 20 bar is a well known cause of neuroexci tatory changes, referred to as the high pressure neurological syndrome . In rodents, symptoms include myoclonia and locomotor activity. In th e present study, we used the 5-HT2A receptor antagonist ketanserin and the 5-HT2C receptor agonist m-CPP to investigate the role of central 5-HT2C receptors in the occurrence of these symptoms. Results suggest that 5-HT2A receptors and 5-HT2C receptors would play a crucial role i n the development of myoclonia and locomotor activity, respectively. T he selectivity of the drugs used, and the central origin of both myocl onia and locomotor activity are discussed.