Leptin receptor expression in the basolateral nucleus of amygdala of conditioned taste aversion rats

AIM:To determine whether serum leptin level and the leptinreceptor (OB-R) expression in the basolateral amygdala (BLA)change following conditioned taste aversion (ERA) formation.METHODS:The serum leptin concentration was measuredby rat leptin RIA kit,long and short forms of leptin receptor(OB-Rb and OB-Ra) mRNA in the brain sections wereexamined by in situ hybridization (ISH) and the expressionof OB-R was assessed by immunohistochemistry ABC methodwith a highly specific goat anti-OB-R antibody.RESULTS:The level of serum leptin didn’t show significantdifference between CTA and control group.Comparing withthe control group,the CTA group had an increase on countof OB-R immunohistochemistry positive-stained cells in theBLA (127±12 vs 48±9 per 1 mm~2).The OB-Rb mRNAexpression level enhanced by 11.9% in the BLA,while OB-Ra mRNA level increased by 7.4% on the choroid plexus inCTA group.So BLA was supposed to be a region whereinteractions between gustatory and vagal signals take place.CONCLUSION:BLA is one of the sites,which are responsiblefor CTA formation in the brain.Leptin and OB-R maybeinvolved in neuronal communication for CTA.So leptin andits receptors probably take part in CTA and integration ofautonomic and extroceptive information.