Training increases [3H]fucose incorporation in chick brain only if followed by memory storage

Incorporation of [3H]fucose into glycoproteins is increased in the forebrain base and anterior forebrain roof of day-old chicks following passive avoidance training. In chicks trained but rendered apparently amnestic by immediate transcranial electroshock, the increased incorporation by comparison with untrained-shocked birds was abolished. If the electroshock was delayed by 10 min, the chicks showed recall for the task and fucose incorporation was increased by comparison with untrained but shocked or trained and immediate-shocked birds. We conclude that the increased incorporation of [3H]fucose is not a result of any concomitant of training but is directly associated with engram formation.