Morphological and histochemical correlation of recovery after spinal transection in rat.

Previous studies from our laboratory have shown disappearance of aminergic terminals with relative preservation of cholinergic activity below the level of the lesion (Rodriques & Sahgal, 1978). Since then we have extended our study to look at the behaviour of aminergic fibres and neurons at various time intervals following the lesion and attempted to correlate with the functional recovery. Three to 4 weeks after spinal transection (thoracic), the rats started to show spinal-stepping which became stronger and dexterous with the passage of time. Up to 6 months after thoracic transection, maximum recovery was observed. Studies of catecholamine fluorescence revealed proliferation of new aminergic terminals which were observed four or five segments below the transection. These observations demonstrate regeneration of aminergic fibres in rat. The significance of the data in the light of neurophysiologic studies will be discussed.