Effects of sea water temperature on bursting pacemaker activity in cell R15 in the intact Aplysia.

Thermosensitivity of bursting pacemaker activity (BPA) in neuron R15 of Aplysia was compared in an intact preparation and after excision of the ganglion containing R15. We noted no differences indicative of an in situ antagonism of cooling-induced suppression of BPA. Interruption of circulation hastened hemolymph cooling during exposure of the animal to cold sea water, suggesting mechanisms to protect R15 and other cells from transient cooling of the animal.