Peptidergic modulation of a neuromuscular junction in Aplysia: bioactivity and immunocytochemistry.
Three endogenous peptides were assayed for bioactivity at an Aplysia neuromuscular junction. Evoked contractions were enhanced by Phe-Met-Arg-Phe-NH2 (FMRFamide) and suppressed by arginine vasotocin; small cardioactive peptide B (SCPB) also enhanced contractions at low concentrations, but caused suppression at higher doses. In accordance with their putative roles as neuromodulators, immunocytochemistry revealed FMRFamide-like and SCPB-like fibers on the muscle surface.
D000818:Animals; D001048:Aplysia / Q000502:physiology*; D001127:Arginine Vasopressin / Q000494:pharmacology / Q000502:physiology*; D019835:FMRFamide; D005455:Fluorescent Antibody Technique; D066298:In Vitro Techniques; D009469:Neuromuscular Junction / Q000187:drug effects / Q000502:physiology*; D009479:Neuropeptides; D009842:Oligopeptides / Q000494:pharmacology / Q000502:physiology*; D009435:Synaptic Transmission
D009479:Neuropeptides; D009842:Oligopeptides; D001127:Arginine Vasopressin; D019835:FMRFamide; C041307:small cardioactive peptide B