Central neural mechanism of the circadian system and its physiological psychology

Abstract

Recent advances on the study of circadian rhythm are reviewed and discussed on the following topics: (1) its phylogeny (the existence of extraretinal photoreceptors, photoreceptors for entrainment, the location of circadian oscillators), (2) its ontogeny and aging, (3) its central neural mechanism (the ablation study of the suprachiasmatic nucleus (SCN), the electrophysiological study of the SCN in multiple unit activity and single neuron activity in rat hypothalamic slice preparation, the use of 2-DG as a functional marker, the transplantation of the SCN, the afferents and efferents of SCN and its peptides), (4) multiple oscillators theory (the anticipatory activities in rats with SCN lesions in response to the restricted feeding schedule, internal desynchronization, splitting), and (5) its psychological significance. Many lines of evidence have shown that the SCN is a putative circadian pacemaker in mammals. On the other hand, other lines of evidence suggest that there are other oscillators outside the SCN. Finally it is emphasized that the chronobiological viewpoint is necessary for the development of psychology. © 1985, The Japanese Psychological Association. All rights reserved.