Anterograde amnesia induced by hyperthermia in rats.

Anterograde amnesia (AA), forgetting of events that occur following a traumatic episode, has recently been demonstrated by using hypothermia as the amnestic agent. However, no data currently exist to indicate if hyperthermia might affect memory processing in a similar manner. Experiments 1 and 2 demonstrated that increasing the colonic body temperature of the rat to 3–4°C or more above normal during avoidance training, produced a significant retention loss when the test occurred 24 hr after training. In Experiment 3, AA resulting from an elevation in temperature was reversed by reheating "amnestic" subjects just prior to the 24-hr test. By rapidly reversing hyperthermia immediately after the training trial with a cooling procedure, Experiment 4 demonstrated that hyperthermia-induced AA was not the result of retrograde influences of the heating treatment. Results are discussed in terms of possible retention deficits which could conceivably follow environmental heat stress or fever hyperthermia resulting from bacterial infection. (PsycINFO Database Record (c) 2010 APA, all rights reserved)