SEGMENTS OF SPINAL CORD HARBORING MOTOR NEURON SOMATA OF RADIAL NERVE OF RABBIT

Introduction- There is paucity of literature as well as lack of consensus regarding the accuracy of cranio-caudal extent of spinal grey column that contains the motor neuron somata of radial nerve.[1],[2] Therefore the present study was undertaken to ascertain the cranio-caudal extent of spinal grey column that harbors the motor neuron somata of radial nerve. Methodology : Six adult rabbits were included in this study. Under general anesthesia the trunk of radial nerve of right side was surgically sectioned in axilla. After post lesional survival period of 8-28 days, the animals were sacrificed and perfusion fixed in 10% buffered formalin. The cervical spinal cord segments 4th, 5th, 6th, 7th, 8th and thoracic spinal cord segment 1st and 2nd were processed for paraffin embedding. From all blocks 40 micron hick serial transverse section were cut. Every 5th section was stained with thionine and studied microscopically to localize motor neuron somata showing either typical chromatolysis [3] or cell body response[4] induced by axotomy. Conclusion - It was concluded that cranio-caudal extent of spinal grey column that contains the of motor neuron somata of radial nerve extended from caudal part of 5th cervical spinal cord segment to cranial part of 1st thoracic spinal cord segment.