Confocal microscopic analysis reveals sprouting of primary afferent fibresin rat dorsal horn after spinal cord injury

Following high thoracic spinal cord transection (SCT) in rats, abnormal cha nges in arterial pressure in response to sensory stimulation (autonomic dys reflexia) are correlated with changes in neural circuitry in the injured sp inal cord. Anterograde transport of wheat germ agglutinin conjugated to Tex as Red(TM) (WGATR) and confocal microscopy were used to characterize the in creased arbourization of A delta and A beta fibre populations in laminae II I-V of the dorsal horn. In cord-injured animals, significantly greater area s of WGATR-labeled fibres were found in the deeper laminae of the dorsal ho rn than in control rats. This increased area likely reflects sprouting of t he A delta, A beta, and possibly C fibre populations. The time course of sp routing matches the onset of autonomic dysreflexia, indicating a possible f unctional correlation between the two phenomena. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.