Dissociable anterograde amnesic effects of retrosplenial cortex and hippocampal lesions on spontaneous object recognition memory in rats
Article first published online: 30 MAR 2012
Copyright © 2012 Wiley Periodicals, Inc.
Volume 22, Issue 9, pages 1868–1875, September 2012
How to Cite
Haijima, A. and Ichitani, Y. (2012), Dissociable anterograde amnesic effects of retrosplenial cortex and hippocampal lesions on spontaneous object recognition memory in rats. Hippocampus, 22: 1868–1875. doi: 10.1002/hipo.22021
- Issue published online: 29 AUG 2012
- Article first published online: 30 MAR 2012
- Manuscript Accepted: 28 FEB 2012
- Japan Society for the Promotion of Science (JSPS). Grant Number: 2153 0759
- nonspatial memory;
- long-term memory;
- excitotoxic lesion;
- retrograde amnesia
The amnesic effects of excitotoxic lesions of the rat retrosplenial cortex (RS) and hippocampus (HPC) in the spontaneous object recognition (SOR) performance were investigated. The SOR test consisted of the sample-exposure session(s) and a test session. First, to test retrograde amnesia, rats received four sample-exposure sessions within a day at 4 weeks and 1 day before the surgery, respectively. In the test sessions conducted 1 week after the surgery, both lesion groups showed a temporally ungraded retrograde amnesia. Second, to test anterograde amnesia, 1- and 4-week retention intervals were inserted between the four sample-exposure sessions and the test session. The RS-lesioned rats showed a retention interval-dependent impairment in the test sessions, while the HPC-lesioned rats showed an impairment regardless of the retention interval. Finally, to test short-term recognition memory, 5- or 30-min delay was interposed between the single sample-exposure session and the test session. Both lesion groups performed normally irrespective of the delay length. These results suggest that both the RS and HPC are important for long-term object recognition memory, but these areas have different roles in it. © 2012 Wiley Periodicals, Inc.