| Abstract: | Neuropeptide Y(NPY) is widely expressed in the central nervous system and influences many physiological processes.It is located within the rat quantitative trait locus(QTL) for alcohol preference on chromosome 4.Alcohol-nonpreferring(NP) rats consume very little alcohol,but have significantly higher NPY expression in the brain than alcohol-preferring(P) rats.We capitalized on this phenotypic difference by creating an Npy knockout(KO) rat using the inbred NP background to evaluate NPY effects on alcohol consumption.Zinc finger nuclease(ZNF) technology was applied,resulting in a 26-bp deletion in the Npy gene.RT-PCR,Western blotting and immunohistochemistry confirmed the absence of Npy mRNA and protein in KO rats.Alcohol consumption was increased in Npy~(+/-) but not Npy~(-/-) rats,while Npy~(-/-) rats displayed significantly lower body weight when compared to Npy~(+/+) rats.In whole brain tissue,expression levels of Npy-related and other alcohol-associated genes,Npy1 r,Npy2r,Npy5 r,Agrp,Mc3 r,Mc4r,Crh and CrMr,were significantly greater in Npy~(-/-) rats,whereas Pome and Crhr2 expressions were highest in Npy~(+/-) rats.These findings suggest that the NPY-system works in close coordination with the melanocortin(MC) and corticotropin-releasing hormone(CRH) systems to modulate alcohol intake and body weight. |
