Balance of activity between LN(v)s and glutamatergic dorsal clock neurons promotes robust circadian rhythms in Drosophila.
Circadian rhythms offer an excellent opportunity to dissect the neural circuits underlying innate behavior because the genes and neurons involved are relatively well understood. We first sought to understand how Drosophila clock neurons interact in the simple circuit that generates circadian rhythms in larval light avoidance. We used genetics to manipulate two groups of clock neurons, increasing or reducing excitability, stopping their molecular clocks, and blocking neurotransmitter release and reception. Our results revealed that lateral neurons (LN(v)s) promote and dorsal clock neurons (DN(1)s) inhibit light avoidance, these neurons probably signal at different times of day, and both signals are required for rhythmic behavior. We found that similar principles apply in the more complex adult circadian circuit that generates locomotor rhythms. Thus, the changing balance in activity between clock neurons with opposing behavioral effects generates robust circadian behavior and probably helps organisms transition between discrete behavioral states, such as sleep and wakefulness.
Department of Biology, New York University, 100 Washington Square East, New York, NY 10003, USA.
Ben
B
Collins
Elizabeth A
EA
Kane
David C
DC
Reeves
Myles H
MH
Akabas
Justin
J
Blau
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D002940:Circadian Rhythm / Q000502:physiology*; D004330:Drosophila; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism*; D009043:Motor Activity / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D056950:Period Circadian Proteins / Q000235:genetics / Q000378:metabolism*; D010775:Photic Stimulation
D029721:Drosophila Proteins; D056950:Period Circadian Proteins; D018698:Glutamic Acid