Interplay between NMDA receptor modulation and Na/K ATPase activity under the social isolation-induced stress in the hippocampus of male rats

Abstract

Living organisms exhibit heightened susceptibility to prolonged social isolation, leading to the onset of diverse pathological processes culminating in various diseases. The nervous system, notably sensitive to such alterations, may manifest neurodegenerative changes. Of particular interest in these conditions is the role of neurotransmitters within the central nervous system (CNS). Thus, our focus was directed towards the glutamate NMDA receptor, known for its pivotal involvement in synaptic plasticity and memory regulation.

Understanding the interplay between glutamate and its receptors, notably the NMDA receptor, with the Na⁺/K⁺-ATPase - an essential player in cellular homeostasis - remains insufficiently explored, especially under social isolation. Consequently, our study aimed to elucidate this relationship within the male rat brain's hippocampus.

Experimental subjects underwent either 30 days of isolation or remained in a communal cage as control animals. Assessing the expression levels of glutamate NMDA-receptor and Na⁺/K⁺-ATPase subunits via the western blot method.

Under prolonged social isolation, a surge in the phosphorylated NR2B subunits of the NMDA receptor indicated heightened receptor activation. Simultaneously, a substantial reduction in Na⁺/K⁺-ATPase activity was observed, potentially linked to decreased α1-subunit expression. These alterations hint at the NMDA receptor's activation and subsequent changes triggered by elevated intracellular Ca²⁺ as likely causes for the diminished Na⁺/K⁺-ATPase activity amidst prolonged social isolation.