title: 5-Hydroxytryptamine (serotonin) causes a reduction in the afterhyperpolarization following the action potential in lamprey motoneurons and premotor interneurons.
abstract: The actions of 5-hydroxytryptamine (5-HT) on single neurons in the lamprey spinal cord have been investigated by intracellular recordings in vitro. Administration of 5-HT either by pressure ejection or by perfusion in the bath caused a reversible reduction of the late phase of the afterhyperpolarization (AHP) following the action potentials. This effect was antagonized by methysergide. A reduction of the late AHP was observed in lateral interneurons, motoneurons and some unclassified cells.
mesh_terms: D000200:Action Potentials / Q000187:drug effects*; D000818:Animals; D005399:Fishes / Q000502:physiology*; D066298:In Vitro Techniques; D007395:Interneurons / Q000187:drug effects; D007798:Lampreys / Q000502:physiology*; D009046:Motor Neurons / Q000187:drug effects; D011985:Receptors, Serotonin / Q000187:drug effects; D012701:Serotonin / Q000494:pharmacology*; D013116:Spinal Cord / Q000187:drug effects*; D009435:Synaptic Transmission / Q000187:drug effects*
chemical_list: D011985:Receptors, Serotonin; D012701:Serotonin