The clock gene period differentially regulates sleep and memory in Drosophila

• Published in: Neurobiology of learning and memory Vol. 153; no. Pt A; pp. 2 - 12
• Main Authors: Fropf, Robin, Zhou, Hong, Yin, Jerry C.P.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-09-2018
• Subjects: Animals; Brain - physiology; Circadian Clocks - genetics; Drosophila; Drosophila - genetics; Drosophila - physiology; Drosophila Proteins - genetics; Drosophila Proteins - physiology; Genotype; Learning - physiology; Memory; Memory - physiology; Neuroglia - physiology; Neurons - physiology; Period; Period Circadian Proteins - genetics; Period Circadian Proteins - physiology; Sleep; Sleep - genetics; Time Factors; Period; Sleep; Drosophila; Memory
• ISSN: 1074-7427; 1095-9564; 1095-9564
• DOI: 10.1016/j.nlm.2018.02.016

•Period mutants have differential time-of-day effects on memory.•Baseline sleep changes in period mutants do not predict memory alterations.•Training-induced sleep plasticity predicts subsequent memory performance.•Manipulating period in different subsets of cells results in distinct phenotypes.
Circadian regulation is a conserved phenomenon across the animal kingdom, and its disruption can have severe behavioral and physiological consequences. Core circadian clock proteins are likewise well conserved from Drosophila to humans. While the molecular clock interactions that regulate circadian rhythms have been extensively described, additional roles for clock genes during complex behaviors are less understood. Here, we show that mutations in the clock gene period result in differential time-of-day effects on acquisition and long-term memory of aversive olfactory conditioning. Sleep is also altered in period mutants: while its overall levels don’t correlate with memory, sleep plasticity in different genotypes correlates with immediate performance after training. We further describe distinct anatomical bases for Period function by manipulating Period activity in restricted brain cells and testing the effects on specific aspects of memory and sleep. In the null mutant background, different features of sleep and memory are affected when we reintroduce a form of the period gene in glia, lateral neurons, and the fan-shaped body. Our results indicate that the role of the clock gene period may be separable in specific aspects of sleep or memory; further studies into the molecular mechanisms of these processes suggest independent neural circuits and molecular cascades that mediate connections between the distinct phenomena.