The biological clock in mammals: structure and function
Lewandowski, M.H.
Postepy Higieny i Medycyny Doswiadczalnej 53(3): 405-422
1999
ISSN/ISBN: 0032-5449 PMID: 10424131 Document Number: 504366
The mammalian circadian timing system has three principal components: entrainment pathways, pacemakers and efferent pathways that couple the pacemaker to effector systems which exhibit temporal organization for physiological processes and behaviour. Light is the primary circadian Zeitgeber and the suprachiasmatic nuclei (SCN) functions as the major pacemaker in the mammalian circadian timing system. A number of investigators have focused attention on the intergeniculate leaflet (IGL) and the geniculohypothalamic tract (GHT) that mediate the effects of nonphotic stimuli on SCN activity and how these pathways interact with photic information being transmitted to the SCN.