The Drosophila Clock Neuron Network Features Diverse Coupling Modes and Requires Network-wide Coherence for Robust Circadian Rhythms

Publication date: 13 December 2016
Source:Cell Reports, Volume 17, Issue 11
Author(s): Zepeng Yao, Amelia J. Bennett, Jenna L. Clem, Orie T. Shafer
In animals, networks of clock neurons containing molecular clocks orchestrate daily rhythms in physiology and behavior. However, how various types of clock neurons communicate and coordinate with one another to produce coherent circadian rhythms is not well understood. Here, we investigate clock neuron coupling in the brain of Drosophila and demonstrate that the fly's various groups of clock neurons display unique and complex coupling relationships to core pacemaker neurons. Furthermore, we find that coordinated free-running rhythms require molecular clock synchrony not only within the well-characterized lateral clock neuron classes but also between lateral clock neurons and dorsal clock neurons. These results uncover unexpected patterns of coupling in the clock neuron network and reveal that robust free-running behavioral rhythms require a coherence of molecular oscillations across most of the fly's clock neuron network.

Graphical abstract

Teaser

Yao et al. show that molecular rhythms of the Drosophila morning and evening circadian oscillators are not tightly coupled. While these two sets of oscillators collaborate to determine the timing of daily activity bouts, additional oscillators, including dorsal clock neurons, are required for robust circadian rhythms under constant conditions.


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