Glutamate-produced long-term potentiation by selective challenge of presynaptic neurons in rat hippocampal cultures.

Excitatory postsynaptic long-term potentiation (LTP) was observed after restricted glutamate or metabotropic agonist application to somata and proximal neurites of identified presynaptic neurons. LTP-induction in this way entailed delays of minutes that correlated with lengths of afferent fibres. Potentiation failed to occur in cells pretreated with colchicine to degrade their microtubular transport matrix. The results suggest fast axonal transport to be a message carrier in the acquisition process of LTP.