Glycoprotein Synthesis Is Necessary for Memory of Sickness‐Induced Learning in Chicks

Can current biochemical models of memory account for sickness‐induced learning? We show that chicks can form an association between pecking a coloured but tasteless lure and becoming ill (LiCI, i.p.) 30 min later. We go on to demonstrate amnesia for this association, induced by intracranial administration of 2‐deoxygalactose (10 μmole per hemisphere, in a 10 γl vol), an inhibitor of the synthesis of glycoproteins of the synaptic membrane, 10 min before pecking. Further, we show that this 2‐deoxygalactose‐induced amnesia is not state dependent. Thus the brain representation of the lure must be held, and require macromolecular syntheses, similar to those found in other forms of learning, for a considerable time before it can be associated with new significant experience. This is incompatible with contiguous synaptic firing views of memory.