EXPRESSION OF MESSENGER-RNAS FOR PREPROTACHYKININ AND NERVE GROWTH-FACTOR RECEPTORS IN THE DORSAL-ROOT GANGLION FOLLOWING PERIPHERAL INFLAMMATION

Nerve growth factor (NGF) plays a dynamic role in the control of subst ance P (SP) levels and synthesis in the dorsal root ganglion (DRG). In the present study, in situ hybridization was used to examine the chan ge of preprotachykinin (PTT), trkA and p75 mRNAs levels in the DRG aft er the injection of complete Freund's adjuvant into the hindpaws of ra ts. Peripheral tissue inflammation increased PTT and p75 mRNAs levels in the DRG, while trkA mRNA levels showed no change. These findings su ggest that p75, in addition to trkA, also may be important in mediatin g the action of NGF on the synthesis of SP in the DRG following periph eral inflammation.