The Journal of Neuroscience, December 15, 2002, 22(24):11035-11044
High-Resolution Analysis of Ethanol-Induced Locomotor Stimulation
in Drosophila
Fred W.
Wolf1, 2,
Aylin R.
Rodan3,
Linus
T.-Y.
Tsai2, and
Ulrike
Heberlein1, 2, 3
1 Department of Anatomy and Programs in
2 Neuroscience and 3 Biological Sciences,
University of California at San Francisco, San Francisco, California
94143
Understanding how ethanol influences behavior is key to deciphering
the mechanisms of ethanol action and alcoholism. In mammals, low doses
of ethanol stimulate locomotion, whereas high doses depress it. The
acute stimulant effect of ethanol has been proposed to be a
manifestation of its rewarding effects. In Drosophila, ethanol exposure transiently potentiates locomotor activity in a
biphasic dose- and time-dependent manner. An initial short-lived peak
of activity corresponds to an olfactory response to ethanol. A second,
longer-lasting period of increased activity coincides with rising
internal ethanol concentrations; these closely parallel concentrations
that stimulate locomotion in mammals. High-resolution analysis of the
walking pattern of individual flies revealed that locomotion consists
of bouts of activity; bout structure can be quantified by bout
frequency, bout length, and the time spent walking at high speeds.
Ethanol exposure induces both dramatic and dynamic changes in bout
structure. Mutants with increased ethanol sensitivity show distinct
changes in ethanol-induced locomotor behavior, as well as
genotype-specific changes in activity bout structure. Thus, the overall
effect of ethanol on locomotor behavior in Drosophila is
caused by changes in discrete quantifiable parameters of walking
pattern. The effects of ethanol on locomotion are comparable in flies
and mammals, suggesting that Drosophila is a suitable model system to study the underlying mechanisms.
Key words:
Drosophila; behavior; ethanol; locomotion; amnesiac; rutabaga
Copyright © 2002 Society for Neuroscience 0270-6474/02/222411035-10$05.00/0