Open AccessCircadian rhythms in neuronal activity propagate through output circuits
Author(s) -
Matthieu Cavey,
Ben Collins,
Claire Bertet,
Justin Blau
Publication year - 2016
Publication title -
nature neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 13.403
H-Index - 422
eISSN - 1546-1726
pISSN - 1097-6256
DOI - 10.1038/nn.4263
Subject(s) - neuroscience , circadian rhythm , rhythm , neuron , premovement neuronal activity , biology , biological neural network , light effects on circadian rhythm , circadian clock , cellular neuroscience , medicine
Twenty-four hour rhythms in behavior are organized by a network of circadian pacemaker neurons. Rhythmic activity in this network is generated by intrinsic rhythms in clock neuron physiology and communication between clock neurons. However, it is poorly understood how the activity of a small number of pacemaker neurons is translated into rhythmic behavior of the whole animal. To understand this, we screened for signals that could identify circadian output circuits in Drosophila melanogaster. We found that leucokinin neuropeptide (LK) and its receptor (LK-R) were required for normal behavioral rhythms. This LK/LK-R circuit connects pacemaker neurons to brain areas that regulate locomotor activity and sleep. Our experiments revealed that pacemaker neurons impose rhythmic activity and excitability on LK- and LK-R-expressing neurons. We also found pacemaker neuron-dependent activity rhythms in a second circadian output pathway controlled by DH44 neuropeptide-expressing neurons. We conclude that rhythmic clock neuron activity propagates to multiple downstream circuits to orchestrate behavioral rhythms.