Open AccessCircadian modulation of light‐induced locomotion responses in Drosophila melanogaster
Author(s) -
Lu B.,
Liu W,
Guo F,
Guo A
Publication year - 2008
Publication title -
genes, brain and behavior
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.315
H-Index - 91
eISSN - 1601-183X
pISSN - 1601-1848
DOI - 10.1111/j.1601-183x.2008.00411.x
Subject(s) - circadian rhythm , entrainment (biomusicology) , light effects on circadian rhythm , stimulus (psychology) , circadian clock , phototaxis , biology , light intensity , neuroscience , rhythm , cryptochrome , drosophila melanogaster , suprachiasmatic nucleus , biophysics , medicine , psychology , optics , genetics , physics , psychotherapist , gene
The relationship between light and the circadian system has long been a matter of discussion. Many studies have focused on entrainment of light with the internal biological clock. Light also functions as an environmental stimulus that affects the physiology and behaviour of animals directly. In this study, we used light as an unexpected stimulus for flies at different circadian times. We found that wildtype flies showed circadian changes in light‐induced locomotion responses. Elevation of locomotor activity by light occurred during the subjective night, and performance in response to light pulses declined to trough during the subjective day. Moreover, arrhythmic mutants lost the rhythm of locomotion responses to light, with promotion of activity by light in timeless 01 mutants and inhibition of activity by light in Clock ar mutants. However, neither ablation of central oscillators nor disturbance of the functional clock inside compound eyes was sufficient to disrupt the rhythm of light responses. We show that, compound eyes, which have been identified as the control point for normal masking (promotion of activity by light), are sufficient but not necessary for paradoxical masking (suppression of activity by light) under high light intensity. This, taken together with the clear difference of light responses in wildtype flies, suggests that two different masking mechanisms may underlie the circadian modulation of light‐induced locomotion responses.