Ae. Mccrea et al., L-DOPA-INDUCED AIR-STEPPING IN PREWEANLING RATS .1. EFFECTS OF DOSE AND AGE, Developmental brain research, 82(1-2), 1994, pp. 136-142
The effects of several doses of L-DOPA (25, 50, 75 and 100 mg/kg) on a
ir-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 t
o 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-d
ependent. On the day of birth, air-stepping consisted primarily of epi
sodes of forelimb alternation; on days 5-20, diagonal progression was
the predominant gait, but beginning at day 10, episodes of air-swimmin
g, air-galloping and other locomotor patterns were interspersed. Not o
nly could the durations of most of these gaits be increased with incre
asing dose of L-DOPA, but at some ages, increasing the dose of L-DOPA
led to gait changes.