Udział receptorów glutaminianergicznych i kortykosteroidowych w generowaniu rytmu theta w obszarze tylnego podwzgórza

Abstract

One of the types of oscillations recorded in the central nervous system (CNS) is the theta rhythm. Functionally, it is related to memory processes, motor activity, and spatial navigation. In rodents, theta rhythm can be recorded in the frequency range of 3-12 Hz from various areas of the CNS, mainly the hippocampal formation (HPC). However, research conducted by Kowalczyk et al. demonstrated that another structure - the posterior hypothalamic area (PHa) is capable not only of modulating the hippocampal theta rhythm, but also of generating the local theta rhythm independently. The main goals of this study were to determine the role of glutamatergic and corticosteroid receptors in the formation and/or modulation of the rhythm in the posterior hypothalamic area and to describe the characteristics of single neurons' discharges in this area related to the local glutamatergic theta rhythm. In the experiments presented in this paper, the theta rhythm was recorded from the PHa preparations maintained extracorporeally. The results presented in this doctoral dissertation prove that kainate-type and NMDA-type glutamatergic receptors, unlike AMPA-type receptors, are involved in the generation of the local theta rhythm in the PHa. In turn, activation of mineralocorticoid receptors modulates the rhythm induced by such a stimulation, leading to an increase in its basic parameters.