Emergence of circadian and photoperiodic system level properties from interactions among pacemaker cells. Export

@article{citeulike:3171033, abstract = {Daily patterns of behavior and physiology in animals in temperate zones often differ substantially between summer and winter. In mammals, this may be a direct consequence of seasonal changes of activity of the suprachiasmatic nucleus (SCN). The purpose of this study was to understand such variation on the basis of the interaction between pacemaker neurons. Computer simulation demonstrates that mutual electrical activation between pacemaker cells in the SCN, in combination with cellular electrical activation by light, is sufficient to explain a variety of circadian phenomena including seasonal changes. These phenomena are: self-excitation, that is, spontaneous development of circadian rhythmicity in the absence of a light-dark cycle; persistent rhythmicity in constant darkness, and loss of circadian rhythmicity in pacemaker output in constant light; entrainment to light-dark cycles; aftereffects of zeitgeber cycles with different periods; adjustment of the circadian patterns to day length; generation of realistic phase response curves to light pulses; and relative independence from day-to-day variation in light intensity. In the model, subsets of cells turn out to be active at specific times of day. This is of functional importance for the exploitation of the SCN to tune specific behavior to specific times of day. Thus, a network of on-off oscillators provides a simple and plausible construct that behaves as a clock with readout for time of day and simultaneously as a clock for all seasons.}, address = {Department of Chronobiology, University of Groningen, The Netherlands. d.g.m.beersma@rug.nl}, author = {Beersma, D. G. and van Bunnik, B. A. and Hut, R. A. and Daan, S.}, citeulike-article-id = {3171033}, citeulike-linkout-0 = {http://dx.doi.org/10.1177/0748730408317992}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/18663243}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=18663243}, doi = {10.1177/0748730408317992}, issn = {0748-7304}, journal = {Journal of biological rhythms}, keywords = {circadian, photic\_entrainment, scn}, month = {August}, number = {4}, pages = {362--373}, posted-at = {2008-08-29 04:39:36}, priority = {3}, title = {Emergence of circadian and photoperiodic system level properties from interactions among pacemaker cells.}, url = {http://dx.doi.org/10.1177/0748730408317992}, volume = {23}, year = {2008} }

TY - JOUR ID - citeulike:3171033 L3 - citeulike-article-id:3171033 N2 - Daily patterns of behavior and physiology in animals in temperate zones often differ substantially between summer and winter. In mammals, this may be a direct consequence of seasonal changes of activity of the suprachiasmatic nucleus (SCN). The purpose of this study was to understand such variation on the basis of the interaction between pacemaker neurons. Computer simulation demonstrates that mutual electrical activation between pacemaker cells in the SCN, in combination with cellular electrical activation by light, is sufficient to explain a variety of circadian phenomena including seasonal changes. These phenomena are: self-excitation, that is, spontaneous development of circadian rhythmicity in the absence of a light-dark cycle; persistent rhythmicity in constant darkness, and loss of circadian rhythmicity in pacemaker output in constant light; entrainment to light-dark cycles; aftereffects of zeitgeber cycles with different periods; adjustment of the circadian patterns to day length; generation of realistic phase response curves to light pulses; and relative independence from day-to-day variation in light intensity. In the model, subsets of cells turn out to be active at specific times of day. This is of functional importance for the exploitation of the SCN to tune specific behavior to specific times of day. Thus, a network of on-off oscillators provides a simple and plausible construct that behaves as a clock with readout for time of day and simultaneously as a clock for all seasons. IS - 4 JF - Journal of biological rhythms SN - 0748-7304 AD - Department of Chronobiology, University of Groningen, The Netherlands. d.g.m.beersma@rug.nl EP - 373 TI - Emergence of circadian and photoperiodic system level properties from interactions among pacemaker cells. VL - 23 SP - 362 KW - circadian KW - photic_entrainment KW - scn AU - Beersma, DG AU - van Bunnik, BA AU - Hut, RA AU - Daan, S PY - 2008/08// UR - http://dx.doi.org/10.1177/0748730408317992 ER -