Effects of 5-HT
These experiments examined the effects of selective 5-HT Water-restricted rats learned to associate a conditioned stimulus (CS) with water in operant chambers. Subsequently, two response levers were made available responding on one lever delivered the CS (now a CRf), while responding on the second lever had no consequences. The effects of agonist and antagonists of 5-HT Responding for a CRf was reduced by the agonists 8-OH-DPAT, DOI and Ro60-0175. 8-OH-DPAT also reduced responding for water and seemed to impair responding in a non-specific fashion. None of the receptor antagonists affected responding. Methylphenidate dose-dependently enhanced responding for a CRf, and this was attenuated by DOI and Ro60-0175. Conversely, the 5-HT No evidence was found for a behaviourally selective effect of 5-HT