Effects of 5-HT in ketanserin-pretreated rats on the structure of feeding behavior

JUAN MANUEL MANCILLA DÍAZ, RODRIGO ERICK ESCARTÍN PÉREZ, VERÓNICA LÓPEZ ALONSO

Abstract


There is evidence that the serotonergic control of feeding behavior is mediated mainly by specific 5-HT1/2 receptors. However, there are not enough data about the specific behavioral mechanisms involved. The aim of present study was to evaluate the effects of 5-HT injection in ketanserin-pretreated rats on feeding behavior structure, in order to reveal the contribution of the 5-HT2A/2C receptors of paraventricular nucleus (PVN) of hypothalamus.and the specific behavioral mechanisms related. Forty rats were maintained on a self-selection feeding paradigm and provided with freely available and separate sources of protein, carbohydrate and fat. The structure of feeding behaviour was videorecorded during a period of 20 min. The experimental room where the rats were observed was kept at 21 ± 1°C on a reversed 12-h light /dark cycle. Our results show that ketanserin-pretreatment attenuated the suppressive effect of 5-HT on carbohydrate intake, even at the onset of the natural (dark) feeding period and it was observed an increase in the duration of carbohydrate meals. The ketanserin-pretreatment was unable to prevent the decrease on local eating rate induced by 5-HT. Our results strongly suggested that stimulation of 5-HT2A/2C receptor is required to the full expression of 5-HT-induced hypophagia, and the contribution of these receptors involves specific behavioral mechanisms, affecting carbohydrates intake and duration.

Keywords


5-HT; ketanserin; food intake; structure of feeding behavior

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DOI: http://dx.doi.org/10.5514/rmac.v32.i1.23257


Editor in Chief:

Dr. Carlos J. Flores-Aguirre

editor_general@rmac-mx.org

ISSN: 0185-4534

ISSN Electrónico: 2007-0802