Mechanosensitive neurons in the spinal cord of the lamprey.

'Fictive locomotion' in the lamprey in vitro spinal cord-notochord preparation can be entrained by side to side movements of the spinal cord-notochord which mimic swimming movements even after transection of dorsal and ventral roots. This study provides direct evidence of mechanosensitive neurons intrinsic to the spinal cord. Neurons with axons located in the lateral aspect of the spinal cord discharge in response to moderate bending movements of the spinal cord. Movements of this amplitude will inevitably occur during normal swimming.