Expression levels of genes encoding melanin concentrating hormone (MCH) and MCH receptor change in taste aversion, but MCH injections do not alleviate aversive responses

► We examine whether MCH and MCHR1 mRNA expression, affects conditioned taste aversion (CTA) in the rat. ► We examine whether i.c.v. injections of MCH during the acquisition and retrieval of LiCl-induced CTA, would alleviate aversive responses. ► MCHR1 mRNA was up-regulated in the hypothalamus and brain stem, MCH mRNA was significantly higher in the hypothalamus, and there was a strong trend suggesting an elevation of MCH and MCHR1 genes in the amygdala. ► Central administration of MCH did not reduce the magnitude of Li-Cl dependant CTA.