Influence of serotonergic transmission anD postsynaptic 5-HT2C action on the feeding behavior of Coturnix japonica (Galliformes: Aves).

We investigated the role of 5-HT2C receptors and serotonergic transmission in the feeding behavior control of quails. Administration of serotonin releaser, fenfluramine (FEN) and 5-HT2C agonists, mCPP and MK212, 1.0 and 3.3 mg/Kg induced significant inhibition of food intake in previously fasted fowls (0.71 +/- 0.18 g and 0.47 +/- 0.2 g; 0.49 +/- 0.22 g and 0.48 +/- 0.29 g; 0.82 +/- 0.13 g and 0.71 +/- 0.16 g, respectively). Control groups ranged from 2.89 +/- 0.21 g to 2.97 +/- 0.22 g, 60 min after reintroduction of food, P < 0.0001). Similar results were obtained with normally fed quails. Both serotonin releaser and 5-HT2C agonists, in a 3.3 mg/Kg dose, induced hypophagy (FEN, 0.78 +/- 0.08 g; mCPP, 0.89 +/- 0.07 g; MK212, 1.25 +/- 0.17 g vs. controls, 2.05 +/- 0.12 g, 120 min after food was presented, P < 0.0001 to P < 0.01). Previous administration of 5-HT2C antagonist, LY53857 (5.0 mg/Kg) blocked the hypophagic response induced by 5-HT2C agonists 60 min after food was reintroduced. Current data show a modulatory role of serotonin release and postsynaptic 5-HT2C receptors in the feeding behavior of quails.