Prolonged inhibition of neurons by neuroendocrine cells in Aplysia.

In the abdominal ganglion of Aplysia, a burst of action potentials in peptide-secreting neuroendocrine cells, the bag cells, produces slow inhibition of two identified bursting pacemaker neurons. The inhibition is due to slow hyperpolarizing potential that reduces bursting pacemaker activity for 3 hours or more. The slow inhibitory potential results from a large and prolonged increase in membrane conductance to potassium ions as well as a slower ionic process that is relatively independent of membrane conductance.