Calcitonin Gene-Related Peptide Neurons Mediate Sleep-Specific Circadian Output in Drosophila

Dec 3, 2014Current biology : CB

Sleep-related daily rhythms controlled by specific nerve cells in fruit flies

AI simplified

Circadian Biology on OpenScience ↗PubMed ↗DOI ↗

Abstract

Diuretic hormone 31 (DH31) is identified as a circadian wake-promoting signal in fruit flies.

DH31 suppresses sleep late at night in fruit flies.
A specific group of dorsal circadian clock neurons expresses DH31 and the receptor for pigment-dispersing factor (PDF).
PDF, secreted by another group of clock neurons, increases DH31 secretion before dawn.
Activation of PDF receptors in DH31-expressing neurons affects sleep without altering circadian rhythms.
This study reveals a neuropeptide relay mechanism for circadian regulation of sleep.

AI simplified

BACKGROUND: Imbalances in amount and timing of sleep are harmful to physical and mental health. Therefore, the study of the underlying mechanisms is of great biological importance. Proper timing and amount of sleep are regulated by both the circadian clock and homeostatic sleep drive. However, very little is known about the cellular and molecular mechanisms by which the circadian clock regulates sleep. In this study, we describe a novel role for diuretic hormone 31 (DH31), the fly homolog of the vertebrate neuropeptide calcitonin gene-related peptide, as a circadian wake-promoting signal that awakens the fly in anticipation of dawn.

RESULTS: Analysis of loss-of-function and gain-of-function Drosophila mutants demonstrates that DH31 suppresses sleep late at night. DH31 is expressed by a subset of dorsal circadian clock neurons that also express the receptor for the circadian neuropeptide pigment-dispersing factor (PDF). PDF secreted by the ventral pacemaker subset of circadian clock neurons acts on PDF receptors in the DH31-expressing dorsal clock neurons to increase DH31 secretion before dawn. Activation of PDF receptors in DH31-positive DN1 specifically affects sleep and has no effect on circadian rhythms, thus constituting a dedicated locus for circadian regulation of sleep.

CONCLUSIONS: We identified a novel signaling molecule (DH31) as part of a neuropeptide relay mechanism for circadian control of sleep. Our results indicate that outputs of the clock controlling sleep and locomotor rhythms are mediated via distinct neuronal pathways.

Full Text

Full text is available at the source.

View full text (XML) ↗View full text ↗

Calcitonin Gene-Related Peptide Neurons Mediate Sleep-Specific Circadian Output in Drosophila

Abstract

Full Text

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief

Abstract

Full Text

Related papers

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief