The effects of 5-HT1A and 5-HT2C receptor agonists on behavioral satiety sequence in rats

The present study examined the effects of 5-HT1A and 5-HT2C receptor agonists on behavioral satiety sequence (BSS) in rats. The 5-HT1A receptor agonist, 8-OH-DPAT (0.5 μg), and the 5-HT2C receptor agonist, Ro-60-0175 (3.0 μg), were injected into the paraventricular nucleus (PVN) of rats. The animals were maintained on an ad libitum feeding paradigm with access to water and individual sources of protein, carbohydrate, and fat. Intra-PVN administration of each agonist was associated with decreased carbohydrate consumption. The effect was enhanced by the administration of both agonists together. Behavioral analysis indicated that co-administration of 8-OH-DPAT and Ro-60-0175 interrupted the natural BSS with an increase in non-feeding behavior, whereas the 8-OH-DPAT alone promoted early development of the natural BSS. In conclusion, the 5-HT receptor agonists affected serotonergic modulation of feeding behavior in a functionally selective way.