5-Hydroxytryptamine depresses reticulospinal excitatory postsynaptic potentials in motoneurons of the lamprey.
Application of 5-hydroxytryptamine (5-HT) to the lamprey spinal cord in vitro reversibly depressed the chemical component of excitatory post-synaptic potentials recorded intracellularly in motoneurons and evoked by stimulation of single reticulospinal Müller cells. The depression could be produced either by local application of small volumes of 10 mM 5-HT to the surface of the spinal cord or by bath-application of 1 or 10 microM 5-HT. No effect on the input resistance of the postsynaptic cells or their sensitivity to glutamate, the suspected transmitter at this synapse, could be detected, suggesting the possibility of a presynaptic action of 5-HT at this synapse in the lamprey.
Buchanan
J T
JT
Department of Biology, Marquette University, Milwaukee, WI 53233.
Grillner
S
S
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D007798:Lampreys / Q000502:physiology*; D009046:Motor Neurons / Q000187:drug effects*; D012154:Reticular Formation / Q000187:drug effects*; D012701:Serotonin / Q000494:pharmacology*; D013116:Spinal Cord / Q000187:drug effects*; D013569:Synapses / Q000187:drug effects*; D013779:Tetrodotoxin / Q000494:pharmacology
D012701:Serotonin; D013779:Tetrodotoxin; D015763:2-Amino-5-phosphonovalerate