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Show April Gold The Role of the Hippocampus in Spatial Pattern Completion \< CrrlcLli. II Kutntr Vh I. mvtrsily of Utah It has been suggested that, the hi^xx-unpus is involved in various functions such as pattern separation, pattern association, and pattern completion. The current study tested male Long-Evans rats on a spatial pattern completion task using a cheeseboard maze apparatus. A black curtain with four extramaze cues surrounded the apparatus. Rats were trained to move a small black block covering a food well and then following eithern a 10 or 30 second del ay return to the same food well with the block removed, Afler reaching criterion performance in terms of accuracy to find the correct location, rats were divided into CA1 subregion, CA3 subregion, and control groups, Afler surgery, the same task was repeated but one, two, three, or four cues were removed in different combinations. The results indicated that controls and CA1 lesions performed well on the task regardless of the availability of one, two, three, or all cues, suggesting intact spatial pattern completion. Following a CA3 lesion, there was an impairment in accuracy compared to the controls when only one cue was available, suggesting an impairment in spatial pattern completion. It appears that the CA3 subregion of the hippocampus plays an important role in spatial pattern completion. 36 |