L-DOPA and quipazine elicit air-stepping in neonatal rats with spinal cord transections.
Acute mid-thoracic spinal cord transection eliminates hindlimb air-stepping in neonatal rats suspended in harnesses and administered L-DOPA. Because spinal cord transection eliminates all descending inputs to the hindlimb locomotor circuits, this experiment determined if coadministration of L-DOPA and quipazine (serotonin receptor agonist) would induce hindlimb air-stepping in rat pups 24 hr after transection. Hindlimb steps of spinally transected pups that received L-DOPA or quipazine alone were infrequent and slow; hindlimb steps induced by L-DOPA + quipazine occurred more frequently and were faster than those elicited by either drug alone. These findings suggest that catecholaminergic and serotonergic systems both contribute to hindlimb stepping.
McEwen
M L
ML
Department of Psychology, University of Florida, Gainesville 32611, USA.
Van Hartesveldt
C
C
Stehouwer
D J
DJ
D000818:Animals; D000831:Animals, Newborn; D015259:Dopamine Agents / Q000494:pharmacology*; D004357:Drug Synergism; D004525:Efferent Pathways / Q000187:drug effects; D006614:Hindlimb / Q000294:innervation*; D007980:Levodopa / Q000494:pharmacology*; D008124:Locomotion / Q000187:drug effects*; D011814:Quipazine / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*; D013116:Spinal Cord / Q000187:drug effects*
D015259:Dopamine Agents; D017366:Serotonin Receptor Agonists; D007980:Levodopa; D011814:Quipazine