Chronic food restriction increases D-1 dopamine receptor agonist-induced phosphorylation of extracellular signal-regulated kinase 1/2 and cyclic AMP response element-binding protein in caudate-putamen and nucleus accumbens.

摘要: Abstract Results of behavioral and c-fos immunohistochemical studies have suggested that chronic food restriction maintenance animals at 75–80% free-feeding body weight may increase d -1 dopamine (DA) receptor function. The purpose the present study was to determine whether DA binding and/or mitogen-activated protein kinase (MAPK) signaling in caudate-putamen (CPu) nucleus accumbens (NAc) are increased food-restricted subjects. In first experiment, saturation antagonist [3H]SCH-23390 indicated no difference between ad libitum fed rats with regard density or affinity sites CPu NAc. second activation extracellular signal-regulated kinases (ERK1/2) cyclic AMP response element-binding (CREB) by i.c.v. injection agonist SKF-82958 (20 μg) were markedly greater than rats. Given a prior finding does not differentially stimulate adenylyl cyclase NAc versus subjects, results suggest receptor-mediated ERK1/2 MAP mediate enhanced downstream CREB, c-fos, responses It is interest also c-Jun N-terminal kinase/stress-activated kinase, but this effect injected those saline vehicle. This represents additional evidence striatal cell presumably procedure, although underlying mechanisms remain be determined. There differences feeding groups levels major phosphatases, MKP-2 PP1. upregulation adaptively serve facilitate associative learning but, same time, vulnerability rewarding addictive properties abused drugs.