Role of NMDA- and non-NMDA Subtypes of Glutamate Receptors in A5 Neuronal Structures in the Regulation of Respiration and Circulation during Thermal Nociceptive Stimulation in Rats

摘要

In narcotized albino rats, thermal nociceptive stimulation elevated systemic blood pressure and increased the frequency of respiratory rhythm generation. Unilateral micro-injection of ketamine hydrochloride, a selective blocker for NMDA receptors, into A5 region did not change the baseline parameters of multineuronal activity in the phrenic nerve and systemic blood pressure. Under conditions of NMDA-receptor blockade, thermal nociceptive stimulation evoked more pronounced respiratory response (in comparison to that observed before ketamine treatment), but induced smaller blood pressure rise. Unilateral microinjection of GAMS, a selective blocker for non-NMDA receptors, into A5 region did not modify the examined baseline parameters and the nociceptive response. It is concluded that during thermal nociceptive stimulation, activity of the respiratory center and blood pressure in rats are controlled by neuronal structures in A5 region via NMDA subtype of glutamate receptors.