Voluntary exercise and tail shock have differential effects on amphetamine-induced dopaminergic toxicity in adult BALB/c mice.
Exercise exerts neuroprotective effects and facilitates neural recovery in animal models of Parkinson's disease. In the present studies, effects of exercise on amphetamine-induced dopaminergic toxicity were assessed in mice housed individually either with or without access to run wheels. Mice in run wheel cages ran approximately 20 000 revolutions/day (over 10 km/day). Some mice received amphetamine (18.5 mg/kg x 4 injections) whereas controls received saline. Amphetamine caused a 90% dopamine depletion in mice housed either with or without run wheels. A precipitous drop was seen in run wheel activity following amphetamine, lasting at least 7 days. A significant decrease in food intake, water intake and body weight also occurred. The opportunity to exercise did not facilitate behavioral or neurochemical recovery at 1, 2 or 3 days, or 2 weeks after injections. Therefore, shock stress, a component of some forced exercise studies, was evaluated to determine whether stress without exercise provided neuroprotection against amphetamine. Results indicate that shock stress exerted neuroprotective effects, reducing the amphetamine-induced dopamine depletion. It is concluded that voluntary running does not afford either behavioral or neuroprotection nor facilitate recovery from amphetamine-induced dopaminergic toxicity; rather, elevated glucocorticoid levels following shock stress were associated with a reduction in the dopamine depletion.
Carlson
Kirsten M
KM
Department of Psychology, Busch Campus, Rutgers University, New Brunswick, New Jersey 08854, USA.
Wagner
George C
GC
D000661:Amphetamine / Q000633:toxicity*; D000818:Animals; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D003342:Corpus Striatum / Q000187:drug effects / Q000503:physiopathology; D003345:Corticosterone / Q000097:blood; D004298:Dopamine / Q000378:metabolism*; D004326:Drinking / Q000187:drug effects / Q000502:physiology; D004435:Eating / Q000187:drug effects / Q000502:physiology; D004597:Electroshock; D007279:Injections, Subcutaneous; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D009498:Neurotoxins / Q000633:toxicity*; D020734:Parkinsonian Disorders / Q000503:physiopathology*; D005082:Physical Exertion / Q000502:physiology*; D013312:Stress, Physiological / Q000503:physiopathology*
D009498:Neurotoxins; D000661:Amphetamine; D004298:Dopamine; D003345:Corticosterone