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Light Preference Assay to Study Innate and Circadian Regulated Photobehavior in Drosophila Larvae
Published on: April 20, 2013
Influence of photoperiod on hormones, behavior, and immune function
James C Walton1, Zachary M Weil, Randy J Nelson
1Department of Neuroscience, The Ohio State University Medical Center, Columbus, OH 43210, USA. walton.315@osu.edu
None:
Photoperiodism is the ability of plants and animals to measure environmental day length to ascertain time of year. Central to the evolution of photoperiodism in animals is the adaptive distribution of energetically challenging activities across the year to optimize reproductive fitness while balancing the energetic tradeoffs necessary for seasonally-appropriate survival strategies. The ability to accurately predict future events requires endogenous mechanisms to permit physiological anticipation of annual conditions. Day length provides a virtually noise free environmental signal to monitor and accurately predict time of the year. In mammals, melatonin provides the hormonal signal transducing day length. Duration of pineal melatonin is inversely related to day length and its secretion drives enduring changes in many physiological systems, including the HPA, HPG, and brain-gut axes, the autonomic nervous system, and the immune system. Thus, melatonin is the fulcrum mediating redistribution of energetic investment among physiological processes to maximize fitness and survival.
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