Synaptophysin and caspase-3 expression on lumbar segments of spinal cord after sensorimotor restriction during early postnatal period and treadmill training

Abstract

The purpose of the current study was to investigate whether locomotor stimulation training could have beneficial effects on spinal cord plastici-ty consequent to sensorimotor restriction (SR). Male Wistar rats were exposed to SR from postnatal day 2 (P2) to P28. Control and experimen-tal rats underwent locomotor stimulation training in a treadmill from P31 to P52. The intensity of the synaptophysin and caspase-3 immunoreac-tion was determined on ventral horn of spinal cord. The synaptophysin immunoreactivity was lower in the ventral horn of sensorimotor restrict-ed rats compared to controls animals and was accompanied by an in-creased caspase-3 immunoreactivity. Those alterations were reversed at the end of the training period. Our results suggest that immobility af-fects the normal developmental process that spinal cord undergoes in early postnatal life influencing both pro-apoptotic and synapse markers. Also, we demonstrated that this phenomenon was reversed by 3 weeks of treadmill training.