Transcribed in synchronicity

The brain's clock is actually an assembly of individually cycling cells, according to results from Shun Yamaguchi, Hitoshi Okamura (Kobe University, Kobe, Japan), and colleagues. But the discrete clocks can work as one because they are synchronized by electrical impulses.

Our internal clock, which controls circadian behaviors and physiology, is a circuitry of many thousands of neurons in the brain called the suprachiasmatic nucleus (SCN). The Kobe group looked at communication within this circuitry in cultured brain slices of transgenic mice using a fluorescent reporter of transcription of a central clock gene, Period (mPer1). They found that mPer1 transcription cycled in nearly every neuron in the SCN. Transcription occurs independently in each cell, and yet in all cells the transcriptional peaks were synchronized: mPer1 levels were...