title: Octopamine alters rhythmic activity in the isolated cardiac ganglion of the crab, Portunus sanguinolentus.
abstract: When applied to the isolated cardiac ganglion of Portunus, octopamine decreases the ganglionic burst frequency and increases the burst duration in a dose-dependent manner over the concentration range 10(-8) M to 10(-6) M. These effects are accompanied by a hyperpolarization (maximum 5 mV) of the cardiac ganglion motor neurones and a decrease in the magnitude of the interburst pacemaker potential in these neurones. The evidence that octopamine plays a cardiomodulatory role in vivo is discussed.
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D003386:Brachyura / Q000502:physiology*; D005724:Ganglia / Q000502:physiology; D006321:Heart / Q000502:physiology; D008564:Membrane Potentials / Q000187:drug effects; D009046:Motor Neurons / Q000187:drug effects; D009655:Octopamine / Q000494:pharmacology*; D010507:Periodicity / Q000187:drug effects
chemical_list: D009655:Octopamine