Performance on spatial working memory tasks after dorsal or ventral hippocampal lesions and adjacent damage to the...

Rats with excitotoxic lesions of the dorsal or ventral hippocampus and control rats were trained on 2 spatial working memory tasks: the standard version of the radial maze with 8 baited arms and the non-matching-to-place procedure in the T maze. Dorsal lesions produced deficits in both tasks, whereas ventral lesions did not affect learning in either of them. A volumetric analysis of subicular damage showed that dorsal hippocampal lesions caused a deficit in the non-matching-to-place only when accompanied by damage to the dorsal subiculum; on the other hand, lesions to the dorsal hippocampus impaired performance in the radial-arm maze regardless of the extent of subicular damage.