Mapping of plasticity and stress-related markers in acute and chronic stress in rats

Abstract

[EN] Stress is a physiological response to any kind of demand or threat that challenges the homeostasis of the organism. Although stress increases alertness and performance, excessive stress often negatively affects cognitive processes such as learning. The present work aims to help elucidating the molecular mechanism underlying the effects of acute and chronic stress on associative learning in rats. Immunohistochemical analysis centred on synaptic plasticity and synapse inhibition were carried out. Indeed, parvalbumin (PV) and calretinin (CR) interneurons were labelled to quantify PV+ and CR+ cells and protein expression. The expression of N-methyl-D-aspartate receptor (NMDAR), relevant in long-term potentiation, was also assessed within those cells. Confocal image analysis was accomplished combining Fiji-ImageJ and Pythons software, a method developed in our lab. This work shows stress-induced alterations in PV and CR expression, but not in NMDAR1. These results add to the increasingly growing field of GABAergic signalling dysfunction in stress-related illnesses that hopefully will provide clinical applications in the future.