Prolonged chronic ethanol exposure alters neuropeptide Y and corticotropin-releasing factor levels in the brain of adult Wistar rats (original) (raw)

There is evidence to suggest that alterations in neuropeptide Y (NPY) and corticotropin-releasing factor (CRF) contribute to the escalated voluntary ethanol intake seen following long term chronic ethanol exposure. The present study assessed whether the duration of chronic ethanol exposure and abstinence alters brain levels of NPY and CRF in adult Wistar rats. NPY-like immunoreactivity (NPY-LI) and CRF-LI were determined in the amygdala (AMYG), frontal cortex (FCTX), hippocampus (HPC) and parietal cortex (PCTX) of adult Wistar rats after chronic ethanol exposure, and 24-hr and 2-wk following withdrawal (WD). Chronic ethanol exposure consisted of either a 2-wk or an 8-wk ethanol vapor regimen. No change in brain levels of NPY-LI, CRF-LI and the NPY-LI/CRF-LI ratio were observed 2-wk following ethanol exposure, whereas, 8-wk of ethanol exposure produced a significant effect on NPY-LI expression in the AMYG and FCTX. Moreover, an 8-wk ethanol vapor regimen significantly increased CRF-LI levels in the HPC and PCTX. Findings from the present study suggest that a longer duration of ethanol vapor, similar to what is required to enhance voluntary drinking, is required to produce changes in NPY-LI and CRF-LI expression in the adult rat brain.