Neuronal arrangement in cervical enlargement of spinal cord of rabbit

Study was conducted using eight adult rabbits with an aim to see the arrangement of motor neuron somata in ventral grey horn of spinal cord of rabbit ‘in the region of cervical enlargement (i.e. C5 - Tl spinal cord segments)’ and further to localize the motor neuron somata of various nerves of forelimb. These rabbits were sacrificed and perfusion fixed in 10% buffered formalin. Cervical spinal cord segments (C5 - C8) and thoracic spinal cord segment (Tl) were processed for paraffin embedding. 40-micron thick serial transverse sections were obtained and every 5^th section stained with thionin. Reconstruction from serial transverse section of different segments was done by Elliot's method and it was found that neurons in the spinal cord are not scattered but they are arranged in vertical columns. Following columns of cells were observed. Ventrolateral column, from 5^th cervical to 1^st thoracic segment. Dorsolateral column, from 5^th cervical to 1^st thoracic segment. Retrodorsolateral column, from 8^th cervical to 1^st thoracic segment. Ventromedial column; from 5^th cervical to 1^st thoracic segment. Dorsomedial column; from 8^th cervical to 1^st thoracic segment. Central column; from 5^th cervical to 6^th cervical segment.