5-HT2 receptor stimulation results in a long term potentiation in spinal reflex pathways (rLTP)(Machacek et al 1999 SFN). Novel gene expression is an essential component in maintaining LTP. Protein kinase C (PKC) ς and PKC γ isoforms are implicated in synaptic plasticity seen in hippocampal LTP. PKC γ is altered in spinal cord following injury. 5-HT2 receptors positively couple to PKC signaling pathways and the long term facilitatory effects of 5-HT may be due to upregulation and chronic activation of PKC in the spinal cord. It was our goal to see if changes in gene expression including PKC isoforms accompany 5-HT2 receptor-induced rLTP. Neonatal rat spinal cords (P8-P11) were isolated, hemisected and maintained in vitro. Electrodes were used to record spinal reflexes. The 5-HT2 receptor agonist DOI was applied and changes in reflexes were recorded. Total RNA was harvested from cords after recording and cDNA was synthesized for PCR analysis of gene expression levels. Differential display PCR was used to id...