Retrosplenial cortex lesions impair water maze strategies learning or spatial place learning depending on prior experience of the rat

There has been debate whether lesions strictly limited to retrosplenial (RS) cortex impair spatial navigation, and how robust and reliable any such impairment is. The present study used a detailed behavioral analysis with naive or strategies-pretrained rats given RS lesions and trained in a water maze (WM). Naive RS lesioned rats failed to acquire the required WM strategies throughout training. Strategies-pretrained RS lesioned rats were specifically impaired in spatial place memory without a WM strategies impairment. Additional training overcame the spatial memory impairment. Thus the behavioral consequences of the lesion depend on the specific previous experience of the animal. The use of appropriate training and testing techniques has revealed experience-dependant dissociable impairments in WM strategies learning and in spatial memory, indicating that RS cortex is involved in both forms of learning.