Attenuation of 5-HT sub(1A) and 5-HT sub(2) but not 5-HT sub(1C) receptor mediated behaviour in rats following chronic treatment with 5-HT receptor agonists, antagonists or anti-depressants

The effects of chronic (10 days) treatment with serotonin (5-HT) receptor agonists on 5-HT sub(1A) receptor mediated lower lip retraction (LLR), 5-HT sub(1C) receptor mediated penile erections (PE) or 5-HT sub(2) receptor mediated head shakes (HS) were studied in rats. It was found that the 5-HT sub(1A) and 5-HT sub(2) receptor mediated behaviour could be attenuated after chronic treatment, whereas 5-HT sub(1C) receptor mediated behaviour remained unchanged. The results demonstrate that 5-HT sub(1A) and 5-HT sub(2) but not 5-HT sub(1C) receptor mediated behaviour can be attenuated by chronic treatment with agonists for these receptors. The 5-HT sub(1C) receptor mediated behaviour remains unchanged in response to chronic agonist treatment.