title: Effect of substance P and thyrotropin-releasing hormone on sympathetic preganglionic neurones in the upper thoracic intermediolateral nucleus of the cat.
abstract: When applied by iontophoresis onto single sympathetic preganglionic neurones in he intermediolateral nucleus of spinal segments T1-T3 in the cat, substance P and thyrotropin-releasing hormone (TRH) each had a weak excitatory effect. Two-thirds of the neurones studied were excited by substance P while one-fifth were excited by TRH. The time courses of the responses to substance P and to TRH were similar, and consisted of an increase in the rate of discharge with a latency of approximately 30 s from the onset of application. They were also prolonged (30-320 s) in afterdischarge following termination of application. These results indicate that substance P and TRH exert excitatory effects on single sympathetic pregnanglionic neurones, and support the possibility that they may be chemical mediators of synaptic transmission in the intermediolateral nucleus.
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology; D002415:Cats; D004558:Electric Stimulation; D009474:Neurons / Q000187:drug effects*; D010455:Peptides / Q000502:physiology; D013116:Spinal Cord / Q000187:drug effects; D013373:Substance P / Q000494:pharmacology*; D013564:Sympathetic Nervous System / Q000187:drug effects*; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*
chemical_list: D010455:Peptides; D013373:Substance P; D013973:Thyrotropin-Releasing Hormone