Peptide regulation of bursting pacemaker activity in a molluscan neurosecretory cell.

Vasopressin and related peptides (10(-9) to 10(-6) molar) induced bursting pacemaker potential activity and altered the current-voltage relations of the membrane in a specific molluscan neurosecretory cell. These effects long outlasted the period of application of the peptides. Sensitivity of the cell to these peptides was primarily localized on the axon hillock region. The observed effects do not resemble conductance changes evoked by conventional neurotransmitters, but rather suggest a membrane regulatory role for these peptides, and thus may be indicative of a new form of information transfer in the nervous system.