[Spatial recognition in cats: effects of parahippocampal lesions]

To determine the contribution of the posterior parahippocampal region to spatial form of one-trial memory in cats, we trained 8 cats to remember the spatial positions of either two different trial-unique objects overlying two of three feeders in a feeder test tray (object-place trials) or simply two of the three feeders (place trials). Four cats then received electrolytic lesions restricted to the posterior parahippocampal region (experimental group) including mainly parahippocampal cortex, parasubiculum and presubiculum. Four other cats comprised sham-operated control group. This group was found to be completely unaffected postoperatively in both types of trials, whereas experimental group showed impaired performance in both types of trials equally. Thus, one-trial memory for object-place association and one-trial memory for two different places in cats appear to be critically dependent on the posterior parahippocampal region.