| Abstract: | Seven male Long-Evans rats with electrodes implanted in the dorsal hippocampus were trained to perform a delayed spatial matching-to-sample task on a radial arm maze. Subseizure-level electrical stimulation of the dorsal hippocampus applied during the study phase disrupted retention of a specific arm when tested at a 20-min delay but had no effects at 1- and 12-min delays. Subseizure-level stimulation of the hippocampus immediately after the study phase resulted in normal retention. In contrast, seizure-level stimulation of the hippocampus applied either during or immediately after the study phase disrupted retention at 1-, 12-, and 20-min delays. Data support the interpretation that the hippocampus is involved in the encoding of critical information (spatiotemporal attributes) in long-term working memory, but not in short-term memory. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
