Editors' ChoiceCircadian Rhythms

Keeping Neuronal Clocks in Time

STKE  25 Nov 2003:
Vol. 2003, Issue 210, pp. tw460-TW460
DOI: 10.1126/stke.2102003TW460

Hundreds of neurons in a region of the brain called the suprachiasmatic nucleus (SCN) comprise the mammalian central circadian clock that controls the rhythm of biological processes and behaviors across dark-light cycles. Each neuron expresses a functional molecular clock, yet the neurons operate collectively as a single pacemaker. Organization of cellular rhythms was directly observed by Yamaguchi et al., who visualized the expression of a bioluminescent marker in the SCN of transgenic mice and observed local transcription of a core clock component. Gene expression was spatially organized across the SCN and appeared as a dorsal-to-ventral wave in real time. The intercellular communication that coordinates this synchronicity involves electrical signals to sustain this temporal and spatial order across the assemblage.

S. Yamaguchi, H. Isejima, T. Matsuo, R. Okura, K. Yagita, M. Kobayashi, H. Okamura, Synchronization of cellular clocks in the suprachiasmatic nucleus. Science 302, 1408-1412 (2003). [Abstract] [Full Text]