title: A high-fat diet or galanin in the PVN decreases phosphorylation of CREB in the nucleus accumbens.
abstract: A high-fat diet (HFD) can increase hypothalamic galanin (GAL). GAL has recently been shown to inhibit opiate reward, which in turn, decreases cAMP response element-binding protein (CREB) in the nucleus accumbens (NAc). We hypothesized that injection of GAL into the paraventricular nucleus (PVN), or consumption of a HFD, would be associated with a decrease in NAc CREB. In Exp. 1, GAL in the PVN of naïve rats decreased phosphorylated-CREB (pCREB) which is the activated form of CREB, in the NAc compared to saline-injected controls. In Exp. 2, rats fed ad libitum HFD for 4 weeks had reduced NAc pCREB levels compared to rats with sporadic tastes of the HFD. Body weight, serum triglyceride and leptin levels were also raised in the chronic HFD-fed rats. These data suggest that PVN GAL or chronic intake of a HFD can decrease NAc pCREB. The implications of these findings may help to explain the lack of opiate-like withdrawal that has been reported in response to overeating a HFD, thereby providing a potential mechanism underlying behavioral differences seen with addiction-like overconsumption of different types of palatable foods.
authors.affiliation: Department of Psychology, Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Bocarsly
authors.affiliation: Department of Psychology, Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA; Department of Psychiatry, McKnight Brain Institute, University of Florida, Gainesville, FL, USA. Electronic address: navena@ufl.edu.
authors.forename: N M
authors.initials: NM
authors.lastname: Avena
mesh_terms: D000818:Animals; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D059305:Diet, High-Fat; D019004:Galanin / Q000008:administration & dosage / Q000378:metabolism*; D020738:Leptin / Q000097:blood; D008297:Male; D009714:Nucleus Accumbens / Q000378:metabolism*; D010286:Paraventricular Hypothalamic Nucleus / Q000378:metabolism*; D010766:Phosphorylation; D051381:Rats; D020318:Rats, Long-Evans; D014280:Triglycerides / Q000097:blood
chemical_list: D017362:Cyclic AMP Response Element-Binding Protein; D020738:Leptin; D014280:Triglycerides; D019004:Galanin
keywords: CREB; addiction; dependence; high-fat diet; nucleus accumbens; obesity