Mechanisms of SCN clock cell interactions producing stable circadian rhythms

Determine the intercellular interaction mechanisms and network structure among neurons in the mammalian suprachiasmatic nucleus (SCN) that generate a stable circadian rhythm.

Background

The mammalian circadian rhythm is generated by genetic oscillations within SCN neurons (clock cells), but the specific ways these neurons interact to produce a coherent and stable system-level rhythm remain unresolved. This uncertainty motivates the need for methods that can infer network connectivity directly from oscillatory time series.

The paper develops a circle-map-based inference approach and demonstrates it on synthetic SCN-like networks comprising two densely connected subregions, examining cases with no, unidirectional, and bidirectional coupling. While these demonstrations showcase the method’s utility, the fundamental biological question of how SCN neurons collectively interact to yield stable circadian rhythms remains open.