L-dopa-induced air-stepping in preweanling rats. I. Effects of dose and age.
The effects of several doses of L-DOPA (25, 50, 75 and 100 mg/kg) on air-stepping were studied in rats on the day of birth and on 5, 10, 15 and 20 days of age. Occurrence of air-stepping increased and latency to air-stepping generally decreased with dose except at 10 days of age; duration of air-stepping increased with increasing dose of L-DOPA at every age. The occurrence of a variety of air-stepping gaits was age-dependent. On the day of birth, air-stepping consisted primarily of episodes of forelimb alternation; on days 5-20, diagonal progression was the predominant gait, but beginning at day 10, episodes of air-swimming, air-galloping and other locomotor patterns were interspersed. Not only could the durations of most of these gaits be increased with increasing dose of L-DOPA, but at some ages, increasing the dose of L-DOPA led to gait changes.
Department of Psychology, University of Florida, Gainesville 32611.
A E
AE
McCrea
D J
DJ
Stehouwer
C
C
Van Hartesveldt
D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D004305:Dose-Response Relationship, Drug; D005260:Female; D005684:Gait / Q000187:drug effects*; D007980:Levodopa / Q000494:pharmacology*; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D051381:Rats; D013239:Stereotyped Behavior / Q000187:drug effects*
D007980:Levodopa