Bulyk R. Morphofunctional substantiation of the circadian rhythms mechanisms in rats

The dissertation deals with ascertaining the central mechanisms of the circadian rhythms in rats, as well as the pineal gland role in the correcting mechanisms of morphological and functional deviations of the rat photoperiodic system under a diverse duration of a photoperiod. It has been analyzed the effects of steady illumination and prolonged darkness on the chronomorphologic and ultrastructural condition of the hypothalamic suprachiasmatic (SCN) and paraventricular nuclei (PVN), hippocamp, suprarenal glands closely connected with the organization and realization of circadian rhythmics. It has been proved that the indicator of early desynchronosis of the central mechanisms of the circadian rhythms of the rat brain is a disturbance of the expression of quick functional response c-fos and determined by it immunospecific c-Fos protein in the pacemaker neurons of the SCN and corticotropin-releasing-hormone-producing and vasopressin-producing subnuclei of the PVN in case of a photoperiodic changes.