Expression of hippocampal serotonin receptors 5‐HT 2C and 5‐HT 5A in a rat model of diet‐induced obesity supplemented with tryptophan

• Published in: International journal of developmental neuroscience 2015-05, Vol.42 (1), p.80-85
• Main Authors: Lopez‐Esparza, Sarahi, Berumen, Laura C., Padilla, Karla, Miledi, Ricardo, García‐Alcocer, Guadalupe
• Format: Article
• Language: English
• ISSN: 0736-5748; 1873-474X
• DOI: 10.1016/j.ijdevneu.2015.02.010

Food intake regulation is a complex mechanism that involves endogenous substances and central nervous system structures like hypothalamus or even hippocampus. The neurotransmitter serotonin is distinguished as food intake mediator; within its multiples receptors, the 5‐HT 2C type is characterized by its inhibitory appetite action but there is no information about 5‐HT 5A receptors involvement in obesity disease. It is also unknown if there are any changes in the receptors expression in rats hippocampus with induced obesity during development through a high energy diet (HED) supplemented with tryptophan (W). To appreciate the receptors expression pattern in the hippocampus, obesity was induced to young Sprague Dawley rats through a HED and supplemented with W. Immunocytochemical and western blot techniques were used to study the receptor distribution and quantify the protein expression. The rats with HED diet developed obesity until week 13 of treatment. The 5‐HT 2C receptor expression decreased in CA1, CA2, CA3 and DG of HED group; and also in CA2, CA3 and DG for HEDW group. The 5‐HT 5A receptor expression only decreased in DG for HED group. Variations of the two serotonin receptors subtypes support their potential role in obesity.