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Updated: Aug 18, 2026

Recording Gamma Band Oscillations in Pedunculopontine Nucleus Neurons
Published on: September 14, 2016
Fast delayed rectifier potassium current is required for circadian neural activity
Jason N Itri1, Stephan Michel, Mariska J Vansteensel
1Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, 760 Westwood Plaza, Los Angeles, California 90024-1759, USA.
Abstract:
In mammals, the precise circadian timing of many biological processes depends on the generation of oscillations in neural activity of pacemaker cells in the suprachiasmatic nucleus (SCN). The ionic mechanisms that underlie these rhythms are largely unknown. Using the mouse brain slice preparation, we show that the magnitude of fast delayed rectifier (FDR) potassium currents has a diurnal rhythm that peaks during the day. Notably, this rhythm continues in constant darkness, providing the first demonstration of the circadian regulation of an intrinsic voltage-gated current in mammalian cells. Blocking this current prevented the daily rhythm in firing rate in SCN neurons. Kv3.1b and Kv3.2 potassium channels were widely distributed within the SCN, with higher expression during the day. We conclude that the FDR is necessary for the circadian modulation of electrical activity in SCN neurons and represents an important part of the ionic basis for the generation of rhythmic output.
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