Mechanism of induction of long term potentiation by the mast cell degranulating peptide.

The properties of Long Term Potentiation (LTP), which is a sustained enhancement of the synaptic response produced by a brief train of electrical stimulation, and its mechanisms are briefly reviewed. Bath application of the mast cell degranulating peptide (MCD) - a peptide isolated from bee venom- also produces in hippocampal slices LTP which is indistinguishable from that produced by a train of electrical stimulation (no change in postsynaptic cell properties, APV sensitive). In vivo push-pull experiments indicate that this LTP is not associated with a sustained enhancement of release of glutamate and aspartate, the two principle transmitters of the hippocampus, but there is a delayed enhanced release of proteins in the extracellular space which may contribute to the maintenance of the potentiation.