S. Fujii et al., EXTRACELLULAR PHOSPHORYLATION OF MEMBRANE-PROTEIN MODIFIES THETA-BURST-INDUCED LONG-TERM POTENTIATION IN CA1 NEURONS OF GUINEA-PIG HIPPOCAMPAL SLICES, Neuroscience letters, 187(2), 1995, pp. 133-136
The involvement of ecto-protein kinase activity in activity-dependent
long-term potentiation (LTP) was studied in CA1 neurons of guinea-pig
hippocampal slices. Application of 5 mu M K-252b, an ecto-protein kina
se inhibitor, blocked LTP induced by a theta-burst stimulation (3 burs
ts composed of 5 pulses at 100 Hz with inter-burst intervals of 200 ms
). On the other hand, under 10 mu M RK682, an ecto-phosphatase inhibit
or, a robust LTP was induced by a weak theta-burst stimulation (3 burs
ts composed of 3 pulses) which was just at the threshold for the induc
tion of LTP in the control perfusate. These findings suggest that ATP
released from presynaptic terminals during the burst stimulation plays
an important role in the induction of LTP through phosphorylation of
extracellular domains of synaptic membrane proteins, as the substrate
for ecto-protein kinase.