Impairment of glycoprotein fucosylation in rat hippocampus and the consequences on memory formation.
The intraventricular injection of 2-deoxy-D-galactose led to a dose- and time-dependent decrease in the fucosylation of hippocampal glycoproteins in rats whereas the incorporation of 3H-N-acetyl-glucosamine was not influenced. This effect is not related to an interference with fucose activating or transferring enzymes but can be abolished by an application of D-galactose. Thus, it seems likely that also in brain tissue a deoxy-galactose induced decrease in the fucosylation is due to a hindering of a glycosidic linkage of fucose to the deoxy-sugar incorporated into glycoprotein chains. As a consequence of an intrahippocampal injection of the deoxy-sugar the retention performance of the animals in a foot-shock motivated brightness discrimination task was considerably impaired. But deoxy-galactose is effective only when administered before and immediately after training whereas either a pre- or a post-training injection did not influence the retention performance of the rats. Thus, an effective metabolic inhibition of the glycoprotein completion by the deoxy-sugar starting at the time of training seems to be crucial to interfere with such morphofunctional alterations in the neuronal network underlying the formation of a memory trace.
D000818:Animals; D004193:Discrimination Learning / Q000187:drug effects; D005643:Fucose / Q000378:metabolism*; D005690:Galactose / Q000031:analogs & derivatives / Q000494:pharmacology; D006023:Glycoproteins / Q000378:metabolism*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D010770:Phosphotransferases / Q000378:metabolism; D017853:Phosphotransferases (Alcohol Group Acceptor); D051381:Rats; D011919:Rats, Inbred Strains
D006023:Glycoproteins; D009419:Nerve Tissue Proteins; D005643:Fucose; C019327:2-deoxy-lyxo-hexose; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); C020153:fucokinase; D005690:Galactose