Characterization of the Function and Localization of the Alpha2A-Adrenergic Receptor in the Bed Nucleus of the Stria Terminalis

Abstract

The bed nucleus of the stria terminalis (BNST) is a region of the brain critical in mediating behavioral and physiological responses to stress and anxiety. Stress is a major cause of relapse for drug addicts attempting to abstain from drugs of abuse. The BNST receives a dense projection of the stress hormone norepinephrine (NE) from the nucleus tractus solitarus, and this projection is critical in stress-induced relapse to drug-seeking in rodent models. NE acts via adrenergic receptors (AR), including the alpha2A-AR subtype of the alpha2-ARs.

This thesis describes work utilizing electrophysiology and immunohistochemistry approaches to characterize the function and localization of the alpha2A-AR in the dorsal BNST. We provide evidence supporting a heterosynaptic localization of the alpha2A-AR on presynaptic glutamate terminals where it functions to regulate glutamate release. We also demonstrate that activation of alpha2-ARs modulates GABAergic transmission in the dorsal BNST.