5-Hydroxytryptamine, substance P and thyrotropin-releasing hormone synapses in the intermediolateral cell column of the rat thoracic spinal cord.
Serotonin-, substance P-, and thyrotropin-releasing hormone-immunoreactive profiles were studied in the intermediolateral cell column at the thoracic level of the rat spinal cord with light- and electron-microscopic immunocytochemistry. For each transmitter, a dense immunoreactive deposit was observed with the light microscope. At ultrastructural level, morphologically identified synapses amounted to 47% of all serotonergic varicosities, to 49% for substance P and 50% for thyrotropin-releasing hormone. Synapses appeared both symmetrical and asymmetrical. In each case, these synapses were mainly axodendritic (98%). These synaptic connections could mediate the physiological influence of these 3 substances in the spinal cord on the cardiovascular system.
Poulat
P
P
INSERM U-336, Développement, Plasticité et Vieillissement du Système Nerveux case 106, U.S.T.L., Montpellier, France.
Marlier
L
L
Rajaofetra
N
N
Privat
A
A
D000818:Animals; D001339:Autonomic Fibers, Preganglionic / Q000502:physiology*; D008297:Male; D051381:Rats; D012701:Serotonin / Q000032:analysis*; D013116:Spinal Cord / Q000737:chemistry / Q000166:cytology*; D013373:Substance P / Q000032:analysis*; D013569:Synapses / Q000737:chemistry* / Q000648:ultrastructure; D013973:Thyrotropin-Releasing Hormone / Q000032:analysis*
D012701:Serotonin; D013373:Substance P; D013973:Thyrotropin-Releasing Hormone