FUCOSE AND FUCOSE-CONTAINING SUGAR EPITOPES ENHANCE HIPPOCAMPAL LONG-TERM POTENTIATION IN THE FREELY MOVING RAT

Male Wistar rats were intrahippocampally injected with L-fucose and th e sugar epitope 2'-fucosyl-lactose prior to induction of long-term pot entiation (LTP). Both substances had only a minimal and short-lasting depressive effect on the monosynaptically evoked field potential recor ded in the dorsal blade of the dentate gyrus of freely moving rats upo n stimulation of the perforant pathway. However, LTP induced by fracti onated tetanization of the perforant pathway, which declined within 24 h in control animals injected with Lactose, remained at the initial l evel even 48 h after tetanization (difference to the control group sig nificant with P < 0.01). The results support earlier findings which ha ve indicated a participation of fucosylated macromolecules in the main tenance of LTP. Different molecular mechanisms concerning the effect o f both substances and the significance of the data in elucidation of t he relationship between LTP and memory formation are discussed.