Glycosylation of proteins during a critical time window is necessary for the maintenance of longterm potentiation in the hippocampal CA1 region

This paper focuses on the role of glycoproteins in activity-dependent synap tic plasticity. The effect of the different inhibitors of protein glycosyla tion, Tunicamycin, Brefeldin A and Swainsonine, on long-term potentiation w as studied in the CA1 region of rat hippocampal slices. Bath application of the inhibitors 60 min before and during tetanization did not interfere wit h the induction of long-term potentiation of the field excitatory postsynap tic potential. However, the potentiation in inhibitor-treated slices decrea sed to baseline levels during 90-180 min. Significant differences in the po tentiation in nontreated slices were detectable 80 min (Tunicamycin), 60 mi n (Brefeldin A) and 75 min (Swainsonine) after tetanization, thus indicatin g the prevention of long-term potentiation maintenance. The application of Swainsonine 120 and 240 min after tetanization did not influence the potent iated field excitatory postsynaptic potential. These data demonstrate the need for undisturbed glycoprotein processing in a time window around longterm potentiation induction to maintain later phas es of long-term potentiation and essential functional implications of prote in glycosylation in mechanisms underlying synaptic plasticity. (C) 1999 IBR O. Published by Elsevier Science Ltd.