RRC ID 11146
Author Picot M, Cusumano P, Klarsfeld A, Ueda R, Rouyer F.
Title Light activates output from evening neurons and inhibits output from morning neurons in the Drosophila circadian clock.
Journal PLoS Biol.
Abstract Animal circadian clocks are based on multiple oscillators whose interactions allow the daily control of complex behaviors. The Drosophila brain contains a circadian clock that controls rest-activity rhythms and relies upon different groups of PERIOD (PER)-expressing neurons. Two distinct oscillators have been functionally characterized under light-dark cycles. Lateral neurons (LNs) that express the pigment-dispersing factor (PDF) drive morning activity, whereas PDF-negative LNs are required for the evening activity. In constant darkness, several lines of evidence indicate that the LN morning oscillator (LN-MO) drives the activity rhythms, whereas the LN evening oscillator (LN-EO) does not. Since mutants devoid of functional CRYPTOCHROME (CRY), as opposed to wild-type flies, are rhythmic in constant light, we analyzed transgenic flies expressing PER or CRY in the LN-MO or LN-EO. We show that, under constant light conditions and reduced CRY function, the LN evening oscillator drives robust activity rhythms, whereas the LN morning oscillator does not. Remarkably, light acts by inhibiting the LN-MO behavioral output and activating the LN-EO behavioral output. Finally, we show that PDF signaling is not required for robust activity rhythms in constant light as opposed to its requirement in constant darkness, further supporting the minor contribution of the morning cells to the behavior in the presence of light. We therefore propose that day-night cycles alternatively activate behavioral outputs of the Drosophila evening and morning lateral neurons.
Volume 5(11)
Pages e315
Published 2007-11
DOI 10.1371/journal.pbio.0050315
PII 07-PLBI-RA-1923
PMID 18044989
PMC PMC2229858
MeSH Animals Behavior, Animal Biological Clocks / physiology* Brain / cytology* Brain / metabolism Circadian Rhythm / physiology* Drosophila / physiology* Drosophila Proteins / genetics Drosophila Proteins / metabolism Gene Expression Genotype Light Motor Activity / physiology Neurons / cytology* Neurons / metabolism Neuropeptides / genetics Neuropeptides / metabolism Nuclear Proteins / genetics Nuclear Proteins / metabolism Organisms, Genetically Modified Period Circadian Proteins Photoperiod* Signal Transduction
IF 9.163
Times Cited 81