Factors affecting sucrose preference behavior in rats with hippocampal lesions

Rats with hippocampal lesions were compared to rats with neocortical lesions and to normal unoperated animals on tests of sucrose preference in both a short (5 min) and a long (24 hr) test session. Sucrose preference behavior was examined on a seven point solution range which extended from water to 48% sucrose. Rats with hippocampal lesions failed to show any preference for sucrose in the 5-min test session, whereas the same animals were identical to controls in the 24-hr test. Additional groups with comparable lesions were also compared on tests of sucrose preference under conditions of both food and water deprivation. The hippocampally-ablated animals showed none or a markedly attenuated preference for sucrose when water deprived. The same animals were identical to the control groups when sucrose preference was tested under food deprivation. Under both deprivation conditions, however, the rats with hippocampal lesions changed significantly more often between the members of the test solution pairs. No differences were found between the cortical and normal unoperated control groups.