The involvement of glutamatergic neurotransmission, via NMDA receptors, in the lateral hypothalamus and perifornical area (LH/PFA) in the hypercapnic ventilatory response

Abstract

Evidence suggests the existence of daily variations in control of the central chemoreflex, and the orexinergic neurons of the lateral hypothalamus and the perifornicial area (LH / PFA) have been considered a mediator of the circadian variations in central chemoreflex, but the mechanisms involved are still not well known. We aim to investigate the possible role of glutamatergic neurotransmission via NMDA ionotropic receptors in the LH/PFA in the modulation of the ventilatory response to hypercapnia in rats during wakefulness and sleep, in the dark and light periods of the diurnal cycle. To this end, experiments in unanesthetized Wistar rats will be performed in a plethysmography system, with simultaneous recording of the following parameters: pulmonary ventilation (VE), electroencephalogram (EEG), electromyogram (EMG) and body temperature (Tb). Pharmacological tools will be used and effects of these approaches will be studied in normocapnia and hypercapnia 7% CO2, during sleep and wekefulness, in both dark and light periods of the diurnal cycle.