PERSISTENT BUT MODIFIABLE RETROGRADE AMNESIA PRODUCED BY HYPOTHERMIA

Rats receiving deep body cooling immediately after passive avoidance training showed retrograde amnesia when tested 1, 5, or 10 days later. Memory loss was substantial but not complete. In Experiment 2 hypothermia treatment 24 hr before training did not interfere with acquisition of the passive avoidance response. These data suggest that the amnesia is based upon disruption of memory traces. Evidence that retrograde amnesia effects can be attenuated by residual memory was indicated by the finding that amnesic animals cooled again after a second training trial showed complete retention at subsequent testing. © 1969.