Buccalin A is a neuropeptide that is found in gastropod motor neurons and is involved in neuromuscular signaling.[1] It reduces current-induced muscle contraction amplitude but not muscle relaxation rate in isolated and washed A. californica accessory radula closer (ARC) muscle fibers when used at a concentration of 10 nM. Buccalin A (10 µM) decreases the amplitude of inhibitory post-synaptic currents (IPSCs) in isolated and perfused voltage-clamped A. californica buccal ganglia.[2]
References:
[1].Cropper, E.C., Miller, M.W., Tenenbaum, R., et al.Structure and action of buccalin: A modulatory neuropeptide localized to an identified small cardioactive peptide-containing cholinergic motor neuron of Aplysia californicaProc. Natl. Acad. Sci. USA85(16)6177-6181(1988).
[2].Baux, G., Fossier, P., Trudeau, L.E., et al.Transmitter release and calcium currents at an Aplysia buccal ganglion synapse--II. Modulation by presynaptic receptorsNeuroscience53(2)581-593(1993).