Kainate Receptors in the Hippocampus of Rats of Strains Differing in Terms of the Level of Nervous System Excitability

Abstract

Glutamate receptors in the CNS play an important role in mediating the mechanisms of differential adaptation to environmental conditions. Currently, kainate receptors (KR) are the best studied in terms of structural-functional characteristics, in both health and disease. Thus, the aims of the present work were: 1) to study the distribution and content of GluR 5/6/7 KR subunits; 2) to study their changes in the pyramidal layer of the hippocampus of rats of strains with genetically determined differences in levels of nervous system excitability on exposure to transient emotional-painful stressors; 3) to assess the sensitivity of hippocampal pyramidal neurons to the actions the KR agonist kainic acid. GluR 5/6/7-containing KR were found to be located predominantly in hippocampal field CA2, with higher levels in low-excitability rats than in high-excitability animals. Transient emotional-pain stress led to increases in the quantity of KR in hippocampal field CA2 in high-excitability rats only. Pyramidal neurons in various hippocampal fields were found to show selective sensitivity to the action of kainic acid, depending on the strain characteristics of the animals’ nervous system excitability.