The effect of 5-hydroxytryptamine given IVC on rat behaviour.

Up till now no univocal answer to the question concerning the role of 5-HT in the control of behaviour of normal animal has been given. The effect of 5-HT was studied after ivc injection. The doses of 10, 50, 80, 100 and 200 mug of 5-HT induced a statistically significant prolongation of immobility time and the decrease in the number of rearings. The dose of 1 mug did not affect animal behaviour. The same dose ivc brought about a statistically significant decrease in locomotor and exploratory activities in rats of high activity, the decrease in locomotor activity in rats of medium-activity but did not affect the behaviour of rats of low activity. 0-1 mug did not bring about any changes in animal behaviour. 5-HT depressed locomotor and exploratory activities in rats in relation to the dose and dependently to the type of behaviour of a normal rat.