Non-uniform upregulation of the autogenic stretch reflex among hindlimb extensors following lateral spinal lesion in the cat.
Exp Brain Res
; 239(9): 2679-2691, 2021 Sep.
Article
en En
| MEDLINE
| ID: mdl-34218298
ABSTRACT
Successful propagation throughout the step cycle is contingent on adequate regulation of whole-limb stiffness by proprioceptive feedback. Following spinal cord injury (SCI), there are changes in the strength and organization of proprioceptive feedback that can result in altered joint stiffness. In this study, we measured changes in autogenic feedback of five hindlimb extensor muscles following chronic low thoracic lateral hemisection (LSH) in decerebrate cats. We present three features of the autogenic stretch reflex obtained using a mechanographic method. Stiffness was a measure of the resistance to stretch during the length change. The dynamic index documented the extent of adaptation or increase of the force response during the hold phase, and the impulse measured the integral of the response from initiation of a stretch to the return to the initial length. The changes took the form of variable and transient increases in the stiffness of vastus (VASTI) group, soleus (SOL), and flexor hallucis longus (FHL), and either increased (VASTI) or decreased adaptation (GAS and PLANT). The stiffness of the gastrocnemius group (GAS) was also variable over time but remained elevated at the final time point. An unexpected finding was that these effects were observed bilaterally. Potential reasons for this finding and possible sources of increased excitability to this muscle group are discussed.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Reflejo de Estiramiento
/
Traumatismos de la Médula Espinal
Límite:
Animals
Idioma:
En
Revista:
Exp Brain Res
Año:
2021
Tipo del documento:
Article
País de afiliación:
Estados Unidos