Behavioral impairments related to cognitive dysfunction in the autoimmune New Zealand black mouse.

The possibility that autoimmunological disorders involving neuronal constituents as autoantigens can result in measurable behavioral impairments prompted the behavioral analysis of the New Zealand black (NZB) mouse strain, known to have high levels of brain-reactive antibodies. Sensorimotor competence and performance in tasks requiring learning and memory were assessed in 7-10-month-old NZB and contrasted with those of CFW mice. The NZB mice showed pronounced deficits in performance of passive and active shock avoidance responses. These deficits could not be accounted for by the slight sensorimotor disadvantage of NZB mice relative to CFW mice. No difference between the two mouse strains was seen in passive avoidance behavior at 1.5 months of age. It is concluded that NZB mice display a behavioral deficit related to cognitive dysfunction and that autoimmune mechanisms may be involved in the etiology of this deficit. Such behavioral disturbances produced by an autoimmune mechanism may have relevance for the neurological declines observed in aging, since the incidence of autoimmune disorders increases markedly in old age.