Lesions of supramammillary nucleus decreae self-grooming behavior of rats placed in an open field
Aim : Although subcortical regions send numerous efferent fibers to the hippocampus, their involvement in hippocampal functions has not been fu11y elucidated. The aim of this study was to determine the efTect of the supram ammillary nucleus (SuM) on the hippocampus. Methods : Neurons within the SuM of rats were destroyed by local injections of an excitotoxin, ibotenic acid, and the efTects of the SuM-lesion on behaviors in an open field were investigated. Results: SuM lesions increased distance traveled, movement time and latency to start grooming, while they decreased time spent grooming. SuM lesions had no efTect on rearing frequency or immobility time. Conclusion : Prolonged exploration and decrease in the total time spent grooming observed in the SuM-lesioned rats were consistent with the beh avi oral characteri stics of hippocamp al -lesioned rats of the previ ous report s, suggesting that the SuM is involved in the establishment of spatial memory by hippocampus during the initial exploration of a novel environment. In addition, the reduction of grooming in the SuM-lesioned animal suggests that SuM may be involved in emotion, such as anxiety. The results ofthis study show the involvement ofthe SuM in hippocampal function and in anxiety perceived in anovel environment.
identifier:The Kitakanto medical journal. 61(3), 287-292, 2011
identifier:The Kitakanto medical journal, 61(3): 287-292
- The Kitakanto medical journal
The Kitakanto medical journal 61 (3), 287-292, 2011-08-01