Hippocampal damage and novelty preference in the ischemic gerbil : dissociating object and arrangement memory

Abstract

The most insidious consequences of transient ischemia are its effect on the hippocampus and the memory systems it serves. The novelty preference test is a direct measure of memory function and has been used in the rat and primate animal models. The gerbil animal model has been used extensively to study the mechanism of ischemic brain damage; however, the novelty preference paradigm has not been used to study memory impairment in this species. In addition, the novelty preference paradigm has not been tested with models of ischemia. In the present experiment, Mongolian gerbils were tested in two different types of novelty-preference tasks (Object and Arrangement) following either ischemic insult or a sham control surgery.

There was no significant difference in preference for novel objects between ischemic and sham groups. However, ischemic gerbils showed a significant decrease in preference for novel arrangements relative to shams. These findings are consistent with previous studies that have demonstrated the dissociation between object and arrangement memory using rats and primates. The results of the present study indicate that the novelty preference paradigm can be successfully used with the gerbil model for ischemic brain damage to study memory impairment and neuroprotective agents.