Aims

To support the free and open dissemination of research findings and information on alcoholism and alcohol-related problems. To encourage open access to peer-reviewed articles free for all to view.

For full versions of posted research articles readers are encouraged to email requests for "electronic reprints" (text file, PDF files, FAX copies) to the corresponding or lead author, who is highlighted in the posting.

___________________________________________

Wednesday, July 13, 2011

Circadian Modulation of Acute Alcohol Sensitivity But Not Acute Tolerance in Drosophila



An increased understanding of the factors affecting behavioral and neurological responses to alcohol and alcohol physiology is necessary given the tremendous toll alcohol abuse and alcoholism exert on individuals and society.

At the behavioral and molecular levels, the response to alcohol appears remarkably conserved from
Drosophila to humans, suggesting that investigations across model species can provide insight into the identification of common modulatory factors.

We investigated the interaction between the circadian clock and alcohol sensitivity, alcohol tolerance, and alcohol absorbance in
Drosophila melanogaster. Using a loss-of-righting reflex (LoRR) assay, we found that flies exhibit a circadian rhythm in the LoRR, with the greatest sensitivity to alcohol occurring from mid to late night, corresponding to the flies' inactive phase.

As predicted, a circadian rhythm in the LoRR was absent in circadian mutant flies and under conditions in which the circadian clock was nonfunctional. Circadian modulation of the response to alcohol was not due to circadian regulation of alcohol absorbance.

Similar to other animals,
Drosophila develop acute and chronic tolerance to alcohol upon repeat exposures. We found that the circadian clock did not modulate the development of acute alcohol tolerance measured as the difference in sensitivity to alcohol between naïve and pre-exposed flies.

Thus, the circadian clock modulates some, but not all, of the behavioral responses to alcohol exposure, suggesting that specific mechanisms underlie the observed circadian modulation of LoRR

This study provides valuable new insights in our understanding of the circadian modulation of alcohol-induced behaviors that ultimately could facilitate preventative measures in combating alcohol abuse and alcoholism





Read Full Abstract

Request Reprint E-Mail:
lyons@bio.fsu.edu