Physiological and pharmacological evidence for histamine as a neurotransmitter in the olfactory CNS of the spiny lobster.
Perfusing histamine (HA, 0.1 microM-1 mM) into the brain of the spiny lobster reversibly altered the spontaneous activity in 24 (86%) of 28 morphologically unidentified, odor-responsive interneurons. The effects of HA were dose-dependent and could be selectively and reversibly antagonized by cimetidine, a vertebrate H2 antagonist, suggesting that the action of HA in the central nervous system (CNS) was mediated by a receptor pharmacologically similar to an HA receptor expressed by lobster olfactory receptor cells. Perfusing HA into the brain also reversibly altered the spontaneous and/or odor-evoked activity of 6 (67%) of 9 morphologically identified, odor responsive interneurons that arborized in the olfactory lobe (OL). These results extend previous evidence from our lab that the OL contains HA-immunoreactive interneurons and that OL tissue can synthesize HA from its precursor and further implicate HA as a putative neurotransmitter in the olfactory CNS of the spiny lobster.
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Whitney Laboratory, University of Florida, St. Augustine 32086.
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D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002927:Cimetidine / Q000494:pharmacology; D006632:Histamine / Q000494:pharmacology* / Q000502:physiology*; D006639:Histidine / Q000494:pharmacology; D007395:Interneurons / Q000187:drug effects*; D008121:Nephropidae / Q000502:physiology*; D009830:Olfactory Bulb / Q000187:drug effects* / Q000502:physiology*; D013194:Staining and Labeling
D006639:Histidine; D002927:Cimetidine; D006632:Histamine