title: Seawater osmolarity influences bursting pacemaker activity in intact Aplysia californica.
abstract: Activity in cell R15 was monitored in a preparation of Aplysia californica in which all sensory inputs and the hemolymph were left intact. R15 exhibited bursting pacemaker activity in situ. Substitution of 93% sea water for normal sea water produced a hyperpolarization of R15 which either silenced the cell or significantly increased the interburst interval in 9 out of 12 of the experiments. Excitatory activity from head ganglia acted to antagonize this inhibitory response. The results provide support for a role of R15 in osmoregulation, and provide a model system in which the interaction of an identified neurosecretory cell, peptide release, and physiological response may be studied.
mesh_terms: D000818:Animals; D001048:Aplysia; D005724:Ganglia / Q000502:physiology*; D007473:Ion Channels / Q000502:physiology*; D008564:Membrane Potentials; D009433:Neural Inhibition; D009474:Neurons / Q000502:physiology; D009489:Neurosecretion; D009435:Synaptic Transmission; D014882:Water-Electrolyte Balance
chemical_list: D007473:Ion Channels