Phase resetting of the mammalian circadian clock relies on a rapid shift of a small population of pacemaker neurons.

Autor: Jos H T Rohling, Henk Tjebbe vanderLeest, Stephan Michel, Mariska J Vansteensel, Johanna H Meijer
Jazyk: angličtina
Rok vydání: 2011
Předmět:
Zdroj: PLoS ONE, Vol 6, Iss 9, p e25437 (2011)
Druh dokumentu: article
ISSN: 1932-6203
DOI: 10.1371/journal.pone.0025437
Popis: The circadian pacemaker of the suprachiasmatic nuclei (SCN) contains a major pacemaker for 24 h rhythms that is synchronized to the external light-dark cycle. In response to a shift in the external cycle, neurons of the SCN resynchronize with different pace. We performed electrical activity recordings of the SCN of rats in vitro following a 6 hour delay of the light-dark cycle and observed a bimodal electrical activity pattern with a shifted and an unshifted component. The shifted component was relatively narrow as compared to the unshifted component (2.2 h and 5.7 h, respectively). Curve fitting and simulations predicted that less than 30% of the neurons contribute to the shifted component and that their phase distribution is small. This prediction was confirmed by electrophysiological recordings of neuronal subpopulations. Only 25% of the neurons exhibited an immediate shift in the phase of the electrical activity rhythms, and the phases of the shifted subpopulations appeared significantly more synchronized as compared to the phases of the unshifted subpopulations (p
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