Low-dose ethanol excites lateral habenula neurons projecting to VTA, RMTg, and raphe.

Low-dose ethanol excites lateral habenula neurons projecting to VTA, RMTg, and raphe. Int J Physiol Pathophysiol Pharmacol. 2017;9(6):217-230 Authors: Fu R, Mei Q, Zuo W, Li J, Gregor D, Bekker A, Ye J Abstract It is unclear how social drinking can contribute to the development of addiction in susceptible individuals. However, alcohol's aversive properties are a well-known factor contributing to its abuse. The lateral habenula (LHb) is a key brain structure responding to various aversive stimuli, including those related to alcohol. We recently reported that ethanol at 10 mM or less that can be achieved by social drinking activates many LHb neurons and drives aversive conditioning. The current study sought to identify LHb circuits that are activated by a low-dose of ethanol using immunohistochemistry and anatomic tracing techniques on adult Sprague-Dawley rats. We showed here that an intraperitoneal injection of ethanol (0.25 g/kg), resulting in a blood ethanol concentration of 5.6 mM, significantly increased the number of cFos immunoreactive (IR) neurons in the LHb. Most of the ethanol-activated cFos-IR LHb neurons expressed vGluT2 (vesicular glutamate transporters 2, a marker of a glutamatergic phenotype). These LHb neurons projected to the ventral tegmental area (VTA), rostromedial tegmental nucleus (RMTg), and dorsal raphe. Moreover, injections of the anterograde tracer AAV-CaMKIIa-eGFP into the lateral hypothalamus produced a sig...
Source: International Journal of Physiology, Pathophysiology and Pharmacology - Category: Physiology Tags: Int J Physiol Pathophysiol Pharmacol Source Type: research