Disturbance and restoration of motor functions in ducks after hemisection of the spinal cord

Summary

Experiments were staged in chronic conditions on 29 ducks. At first, hemisection of the spinal cord was done at the level of the sixth cervical vertebra, and then two-stage excision of the hemispheres of the forebrain was performed. Each of the subsequent operations was carried out after the highest possible restoration level of disturbed functions (caused by the previous operation) was reached. Urethane anesthesia (1.0 gm/kg of body weight) was used.

Locomotor functional disturbances caused by the spinal cord hemisection in ducks are compensated, although only partially, in about 3 months. Excision of one of the hemispheres of the forebrain led to decompensation of the motor functions restored earlier. Removal of one of the forebrain hemispheres in ducks caused locomotor functional disturbances not only as a result of functional decompensation of one extremity (at the side of hemisection), but also due to disturbed function of the second extremity. The highest possible restoration level of the secondarily disturbed standing and walking functions occurred somewhat earlier and was somewhat more complete after the removal of the contralateral hemisphere of the forebrain (in 1–1.5 months) than following the excision of the homolateral hemisphere (in 1.5–2 months). Removal of the second forebrain hemisphere again provoked decompensation of the twice restored standing and walking functions; the latter were restored three weeks after the last operation.