Control of Central and Peripheral Targets by a Multifunctional Peptidergic Interneuron

In the terrestrial slug, Limax maximus, feeding activity and cardiovascular function have been shown to be correlated. For example, in intact animals, both feeding responsiveness and heart activity are suppressed during dehydration (Grega and Prior, 1986). The paired peptidergic buccal ganglion neurons RB1 and LB1 have dramatic modulatory effects on both the feeding motor program (FMP) and the force of heart contraction (Welsford and Prior, 1991). The B1 neurons appear to contain the small cardioactive peptides (SCPs). Observations have a frequency dependent excitation of both the FMP and the heart demonstrated by intracellular stimulation of B1. Thus, interneuron B1 may serve to mediate the coincident modulation of multiple responses to physiological stresses.