Long projections from the brainstem to the lumbar cord activate locomotion. Using in vitro neonatal rats our laboratory showed that relay (propriospinal - PS) neurons also contribute to transmission of the locomotor signal. This thesis examines whether locomotor-related PS neurons exist in adult mammals, which has important clinical implications. The brainstem of adult decerebrate rats was stimulated to elicit stepping. The following manipulations were performed: 1) suppression of synaptic transmission to PS neurons, 2) lesioning of direct bulbospinal projections to lumbar segments, and 3) neurochemical excitation of PS neurons. In addition, in the absence of brainstem stimulation, the ability of neurochemically excited PS neurons to induce stepping was examined. Brainstem-evoked locomotion was suppressed by synaptic blockade, enhanced by PS neuron excitation, persists after lesioning of long-direct projections, and hindlimb stepping was elicited by PS neuron excitation alone. The findings support the existence of a locomotor-related PS system in adult mammals. / October 2016
| Identifer | oai:union.ndltd.org:MANITOBA/oai:mspace.lib.umanitoba.ca:1993/31826 |
| Date | 20 September 2016 |
| Creators | Ansari, Jahanzeb |
| Contributors | Schmidt, Brian (Physiology and Pathophysiology) Stecina, Katinka (Physiology and Pathophysiology), Cowley, Kristine (Physiology and Pathophysiology) MacNeil, Brian (Physical Therapy) |
| Source Sets | University of Manitoba Canada |
| Detected Language | English |
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