[Mechanisms of stepping rhythm formation during epidural spinal cord stimulation in decerebrated and spinal cord transected cats].
The mechanisms of stepping pattern formation during epidural spinal cord stimulation in decerebrated and chronically spinal cord transected cats have been investigated. The features of the stepping performance in hindlimb muscles depending on the parameters of epidural stimulation and afferent input were determined. It was shown that, at nonoptimal parameters of stimulation, stepping movements are not induced. In response to the stimulation, reflectory muscle responses are evoked only. Epidural stimulation with optimal parameters induces coordinated stepping movements in hindlimbs with normal rhythm (0.8-1 Hz), which is accompanied by the electromyographic bursting activity of the corresponding muscles. In decerebrated cats, the formation of electromyographic bursts occurs due to the modulation of early responses and the late polysynaptic activity. In chronically spinal cord transected cats, this process is provided mainly by the amplitude modulation of early responses. The formation of the stepping pattern in decerebrated cats with the participation of spinal interneurons responsible for the polysynaptic activity allows one to perform its correction on the basis of the processing of afferent signals. The activation of this system in chronically spinal cord transected cats can be realized by afferent stimulation alone.
Bogacheva
I N
IN
Nikitin
O A
OA
Musienko
P E
PE
Savokhin
A A
AA
Gerasimenko
Iu P
IuP
D000344:Afferent Pathways; D000818:Animals; D002415:Cats; D003655:Decerebrate State; D004558:Electric Stimulation; D004576:Electromyography; D004824:Epidural Space; D006614:Hindlimb; D008124:Locomotion; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology; D010507:Periodicity; D011930:Reaction Time; D013116:Spinal Cord / Q000502:physiology*