CHANGES IN THE MORPHOLOGY OF SYMPATHETIC PREGANGLIONIC NEURONS PARALLEL THE DEVELOPMENT OF AUTONOMIC DYSREFLEXIA AFTER SPINAL-CORD INJURY IN RATS

Following spinal cord transection (SCT), sensory input to the spinal c ord causes increases in arterial pressure that are small in rats 1 wee k after SCT, but become large and well established by 2 weeks. Moreove r, sympathetic preganglionic neurons (SPNs) undergo atrophy by 1 week after SCT, and regeneration of these neurons may be an important facto r in the etiology of this autonomic dysreflexia. Therefore, we examine d the morphology of SPNs 2 weeks after SCT using retrograde transport of the cholera toxin subunit B. The dendritic arbors of SPNs were re-e stablished by 2 weeks after SCT. This regeneration parallels the time course of the development of autonomic dysreflexia after cord injury i n the rat, and may play a role in initiating this disorder. (C) 1998 E lsevier Science Ireland Ltd.