Circadian rhythms

The rhythm regulator

The small ventral lateral neurons (sLNvs) are the main clock neurons in fruitflies and show circadian changes in excitability and axonal terminal width, which are at their greatest at dawn. This study revealed that sLNvs also show circadian changes in axon volume, suggesting the involvement of an actin-related mechanism. Indeed, levels of Rho1 — a GTPase implicated in actin dynamics — exhibited circadian oscillations in sLNvs, and overexpressed Rho1 maintained axon terminals in a retracted state, leading to arrhythmic circadian behaviour and impaired regulation of downstream clock neurons. Thus, oscillatory Rho1 activity is a key circadian regulator in fruitflies.


  1. 1

    Petsakou, A., Sapsis, T. P. & Blau, J. Circadian rhythms in Rho1 activity regulate neuronal plasticity and network hierarchy. Cell http:/ (2015)

Download references


Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Yates, D. The rhythm regulator. Nat Rev Neurosci 16, 510 (2015).

Download citation


Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing