LEARNING IN YEAR-OLD FEMALE AUTOIMMUNE BXSB MICE

BXSB/MpJ-Yaa and NZB/BINJ mice have been used as animal models fur bot h developmental learning disability and systemic autoimmune disease. A pproximately 40-60% of these animals show ectopic clusters of neurons in Layer I of cortex similar to those found in postmortem analyses of human dyslexics, and all exhibit an autoimmune condition similar to sy stemic lupus erythematosus (SLE) in humans. The expression of immune d isease in the BXSB strain, unlike in humans, is more severe in males t han females. Most previous studies have examined the behavioral sequel ae of neocortical ectopias at a relatively young age, when the BXSB fe males (unlike the male BXSB and female and male NZBs) are nor yet show ing high titers of autoantibodies associated with their lupus-like for m of autoimmune disease. This study examined the behavior of BXSB fema les at an age subsequent to autoimmune disease onset. hen contrasted w ith younger animals, year-old BXSB females showed good learning behavi or, with no differences in Lashley maze learning and remarkably good p erformance in a visual discrimination learning task. These results are consistent with other data which indicate that many types of learning behavior are apparently unperturbed by systemic autoimmune disease. R esults also showed significant interactions between a measure of later al paw preference and the presence or absence of ectopias in Lashley m aze learning. Animals without ectopias that exhibited a right lateral paw preference showed the greatest number of errors on a number of tes t measures. These findings support previous results indicating that be havioral effects associated with ectopias may vary based upon the beha vioral laterality of affected animals.