Sensory, motor and cognitive alterations in aged cats.

These experiments were designed to assess some of the sensory, motor and cognitive alterations that occur in aged cats. Three groups of cats (1-3, 5-9 and 11-16 years of age) were tested in four behavioral tasks to assess age-dependent changes in locomotor activity, fine motor coordination, reactivity to auditory stimuli and spatial reversal learning. In tests of locomotor activity, 11-16 year old cats displayed altered patterns of habituation compared to 1-3 and 5-9 year cats. There were no decrements in fine motor coordination in the 11-16 year cats as measured by their ability to traverse planks of varying width or by their scores on a neurological examination. The 11-16 and 5-9 year cats both displayed increased reactivity to auditory stimuli. On tests of spatial reversal learning, 11-16 year cats displayed superior performance compared to 5-9 or 1-3 year animals, making fewer errors and requiring fewer trials to reach criterion. These findings indicate that a series of age-related behavioral changes occurs in the cat. Some of these may be related to morphological and neurophysiological alterations in neurons in the caudate nucleus.