INHIBITION OF CONSOLIDATION AND RETRIEVAL STAGES OF PASSIVE-AVOIDANCE LEARNING BY ANTIBODIES TO GANGLIOSIDES

Antiserum to brain gangliosides injected into the lateral ventricle of rats and mice produces retrograde amnesia (one-trial passive-avoidance learning). Experiments are now reported examining the effects of altering the time intervals between training and injection in order to determine the phases of learning that are inhibited and for comparison with other agents used to produce amnesia. Antiganglioside serum injected intraventricularly into mice caused inhibition when injected as long as 6 hr before training and 19 hr after training. The antiserum appears to be similar to other agents (ECS, antibiotics) in affecting consolidation rather than acquisition. Acquisition was not affected since no inhibition was seen until 8 to 12 hr after administration. When the antiserum to gangliosides was injected as long as 48 hr after training it caused a temporary loss of retrieval. Controls for these effects were based on the inactivity of antiserum from which the antibodies were removed by absorption with pure GM1 ganglioside. Although retrograde amnesia produced by the immunological agent does not differ qualitatively from that seen with electroconvulsive shock and protein synthesis inhibition, antibodies against gangliosides have greater potential for delineating critical sites in consolidation because of their structural specificity and because their localization can be more precisely controlled experimentally. © 1979 Academic Press, Inc.