Increase in glutamate receptors following repetitive electrical stimulation in hippocampal slices

Repetitive electrical stimulation of identified pathways in the hippocampal slice preparation induces long-term potentiation (LTP) of synaptic transmission and is accompanied by a long-lasting (up to 30 minutes) increase in L-³H-glutamate accumulation by the slices. This increased accumulation of ³H-glutamate is restricted to the terminal field of the stimulated fibers and does not seem to represent a non-specific increased accumulation of amino acids. In addition, synaptic membranes prepared from stimulated slices exhibit an increase in the maximal number of the sodium-independent high-affinity binding sites for ³H-glutamate without changes in their affinity. These results suggest that repetitive electrical stimulation elicits an increased number of glutamate receptors which might be responsible for LTP.