Daily passive cycling attenuates the hyperexcitability and restores the responsiveness of the extensor monosynaptic reflex to quipazine in the chronic spinally transected rat.
J Neurotrauma
; 31(12): 1083-7, 2014 Jun 15.
Article
in En
| MEDLINE
| ID: mdl-24484172
ABSTRACT
Activity-based interventions such as locomotor training or passive cycling have a positive influence on the spinal circuitry and recovery following a spinal cord injury (SCI). The use of quipazine in combination with exercise training has demonstrated a greater functional recovery than has exercise training alone. However, the influence of exercise or training on the responsiveness of the spinal cord to quipazine has not been examined following a chronic spinal transection. The purpose of this study was to characterize the flexor and extensor monosynaptic reflex (MSR) response pre- and post-quipazine in chronic complete spinally transected rats that either underwent daily passive cycling for 3 months or did not receive passive cycling. Following a chronic spinal transection, the extensor MSR demonstrated a hyperreflexive response (fivefold increase) to afferent stimuli, and did not respond to quipazine injection. With daily passive cycling, the extensor MSR hyperexcitability was attenuated, and the MSR amplitude increased 72% following quipazine injection (p<0.004), which was comparable to the extensor MSR response (94%) in the control group. For both chronic spinal transection groups, the flexor MSR amplitudes were not altered following quipazine injection, whereas in the control group the flexor MSR amplitude increased 86% in response to quipazine (p<0.004). These results demonstrate that passive cycling attenuates the hyperreflexive response of the extensor MSR following a chronic SCI, and restores the MSR response to quipazine.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Quipazine
/
Reflex, Monosynaptic
/
Spinal Cord Injuries
/
Serotonin Receptor Agonists
/
Recovery of Function
/
Exercise Therapy
Limits:
Animals
Language:
En
Journal:
J Neurotrauma
Journal subject:
NEUROLOGIA
/
TRAUMATOLOGIA
Year:
2014
Document type:
Article
Affiliation country:
Canada