title: Characteristics of dorsal root potentials recorded from the isolated spinal cord of the neonate rat.
abstract: Dorsal root potentials (DRP) and dorsal root reflexes (DRR) have been recorded from the isolated cord of the neonate rat. A single stimulus to the adjacent rostral or adjacent caudal dorsal root or dorsal columns evoked a DRP, the peak amplitude of which was reached in 110--115 msec and which decayed exponentially over most of its time course (time constant 800--850 msec). The same stimuli evoked field potentials in the dorsal horn comprising fast negative, slow negative and slow positive potentials. DRP had a lower threshold than DRR and reached a maximal amplitude at stimulus voltages sub-maximal for DRR. Increasing the intensity of stimulation shortened the latency of DRP and prolonged its time course. DRR and DRP were depressed by a prior conditioning stimulus (CS) and by the addition of Mg++ ions to the bathing solution. A CS was more effective in producing depression of responses evoked more rostrally than more caudally.
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D004553:Electric Conductivity / Q000187:drug effects; D004558:Electric Stimulation; D005071:Evoked Potentials; D005260:Female; D005727:Ganglia, Spinal / Q000502:physiology*; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D051381:Rats; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology*
chemical_list: D008274:Magnesium