Spatial learning and motor deficits in aged rats.

Young (3 months) and aged (24 months) rats were compared on a range of behavioural tests. The aged animals were impaired in their acquisition of a spatial learning task in the Morris water maze, as well as showing deficits in motor coordination, swimming efficiency, and spontaneous locomotion and exploration in an open field. Qualitative observation and correlation analyses indicated that the aged group was heterogeneous in the degree of impairments manifested by the individual animals, and suggested that the development of impairments may progress with aging at different rates in the various tasks and possibly in different underlying neuroanatomical systems.