The effect of hyperpolarization of cell R15 on the hemolymph composition of intact Aplysia

Experiments were performed to determine the effects of the activity pattern in identified neurosecretory cell R15 on the distribution of osmolytes in Aplysia californica . Exposure of the animal to dilute sea water produces a reduction of bursting pacemaker activity in R15. The magnitude of burst frequency reduction is correlated wih the degree to which the salinity is reduced. When R15 is silenced by passage of current through a microelectrode, a number of changes occur in the concentration of osmolytes in the hemolymph. These changes include a 13% increase in K super(+), and a 70% increase in ammonia levels.