Biological Rhythms Workshop IB: neurophysiology of SCN pacemaker function

Cold Spring Harb Symp Quant Biol. 2007;72:21-33. doi: 10.1101/sqb.2007.72.061.


Pacemakers are functional units capable of generating oscillations that synchronize downstream rhythms. In mammals, the suprachiasmatic nucleus (SCN) of the hypothalamus is a circadian pacemaker composed of individual neurons that intrinsically express a near 24-hour rhythm in gene expression. Rhythmic gene expression is tightly coupled to a rhythm in spontaneous firing rate via intrinsic daily regulation of potassium current. Recent progress in the field indicates that SCN pacemaking is a specialized property that emerges from intrinsic features of single cells, structural connectivity among cells, and activity dynamics within the SCN. The focus of this chapter is on how Nature built a functional pacemaker from many individual oscillators that is capable of coordinating the daily timing of essential brain and physiological processes.

Publication types

  • Congress

MeSH terms

  • Animals
  • Circadian Rhythm / genetics
  • Circadian Rhythm / physiology*
  • Electrophysiology
  • Eye Proteins / genetics
  • Eye Proteins / physiology
  • Feedback, Physiological
  • Models, Neurological
  • Neurophysiology
  • Period Circadian Proteins
  • Potassium Channels / physiology
  • Suprachiasmatic Nucleus / physiology*


  • Eye Proteins
  • Period Circadian Proteins
  • Potassium Channels