Acute alcohol administration improves skilled reaching success in intact but not 6-OHDA dopamine depleted rats: a subsystems analysis of the motoric and anxiolytic effects of alcohol.
Low doses of alcohol impair movement and reduce anxiety. Most assessments of movement under ethyl alcohol (alcohol) in the rat have been tests of whole body movements, however. There has been no examination of the effects of alcohol on skilled limb movements, such as reaching for food with a forelimb. This was the purpose of the present study. Rats were trained to reach through a slot of a box with a forelimb in order to obtain a food pellet located on an external shelf. Once asymptotic performance was achieved, rats were given alcohol (20 ml of 8, 12 or 20% (v/v) solution) in separate tests to establish a relationship between alcohol ingestion and skilled reaching performance. Acute treatment with all doses of alcohol impaired postural support, but doses of 8 and 12% alcohol improved skilled reaching success. Qualitative analysis of the movements used for reaching at doses of 8 and 12% indicated that some limb components of the reaching movement were also impaired, perhaps secondarily due to impaired posture. In contrast, the reaching success of rats with unilateral dopamine depletion, induced with the neurotoxin 6-hydroxydopamine (6-OHDA) in the nigrostriatal bundle, was impaired by the same dose of alcohol that improved reaching success in control rats. The finding of improved success in reaching associated with reduced postural support in normal rats suggests a differential action of alcohol on movement subsystems underlying posture relative to skilled movement that depends upon an intact dopaminergic system. The results are also discussed with respect to the relationship of subsystems of movement and anxiety.
Metz
Gerlinde A
GA
Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, Alta., Canada T1K 3M4. gerlinde.metz@uleth.ca
Gonzalez
Claudia L R
CL
Piecharka
Dionne M
DM
Whishaw
Ian Q
IQ
D000222:Adaptation, Physiological / Q000502:physiology; D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology; D002492:Central Nervous System Depressants / Q000494:pharmacology; D004298:Dopamine / Q000172:deficiency / Q000502:physiology*; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D009048:Motor Skills / Q000187:drug effects*; D009068:Movement / Q000187:drug effects; D016627:Oxidopamine / Q000378:metabolism / Q000494:pharmacology; D011597:Psychomotor Performance / Q000187:drug effects; D051381:Rats; D020318:Rats, Long-Evans; D013378:Substantia Nigra / Q000187:drug effects
D014151:Anti-Anxiety Agents; D002492:Central Nervous System Depressants; D000431:Ethanol; D016627:Oxidopamine; D004298:Dopamine