title: Peptide cotransmitter at a neuromuscular junction.
abstract: The neuropeptide proctolin (H-Arg-Tyr-Leu-Pro-Thr-OH) is present in the nerve terminals of an identified slow skeletal motoneuron in the cockroach. Proctolin is released onto the target muscle, a coxal depressor, by neuron stimulation and by depolarization with potassium. The physiological action of the motoneuron suggests that proctolin acts as a cotransmitter. Proctolin and neural stimulation produce delayed and sustained contractile effects without muscle depolarization.
mesh_terms: D000200:Action Potentials; D000818:Animals; D003058:Cockroaches; D009119:Muscle Contraction; D009411:Nerve Endings / Q000502:physiology; D009469:Neuromuscular Junction / Q000502:physiology*; D009479:Neuropeptides; D018377:Neurotransmitter Agents / Q000502:physiology*; D009842:Oligopeptides / Q000502:physiology*; D009435:Synaptic Transmission
chemical_list: D009479:Neuropeptides; D018377:Neurotransmitter Agents; D009842:Oligopeptides; C011536:proctolin