Daily electrical activity in the master circadian clock of a diurnal mammal
Abstract
Circadian rhythms in mammals are orchestrated by a central clock within the suprachiasmatic nuclei (SCN). Our understanding of the electrophysiological basis of SCN activity comes overwhelmingly from a small number of nocturnal rodent species, and the extent to which these are retained in day-active animals remains unclear. Here, we recorded the spontaneous and evoked electrical activity of single SCN neurons in the diurnal rodent Rhabdomys pumilio, and developed cutting-edge data assimilation and mathematical modeling approaches to uncover the underlying ionic mechanisms. As in nocturnal rodents, R. pumilio SCN neurons were more excited during daytime hours. By contrast, the evoked activity of R. pumilio neurons included a prominent suppressive response that is not present in the SCN of nocturnal rodents. Our modeling revealed and subsequent experiments confirmed transient subthreshold A-type potassium channels as the primary determinant of this response, and suggest a key role for this ionic mechanism in optimizing SCN function to accommodate R. pumilio’s diurnal niche.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 30, 2021
- Source ID
- 10.7554/elife.68179
Entities
People
- Beatriz Baño‐Otálora
- Casey O Diekman
- Matthew Moye
- Mino D C Belle
- Robert J Lucas
- Timothy Brown
Organizations
- Army Research Office
- Biotechnology and Biological Sciences Research Council
- Engineering and Physical Sciences Research Council
- National Science Foundation
- New Jersey Institute of Technology
- UK Fulbright Commission
- University of Exeter
- University of Manchester
- Wellcome Trust