Effect of brain iso-antibodies on learning and memory in the rat

Abstract

Naive Wistar rats that had been immunized with a crude microsomal fraction from rat brain or rat liver required a greater number of trials to learn a visual discrimination problem than rats injected with saline solution. The degree of impairment of learning varied from experiment to experiment. However, analysis of variance on the results of four experiments showed that differences between the performances of the immunized animals and the control animals were statistically significant. When trained rats that had required a similar number of trials to learn a visual discrimination task were studied, the animals that subsequently were immunized for 1 month with rat brain or rat liver proteins performed the learned task and learned a new problem as well as the control animals that had been injected with saline solution. However, when reversal of the discrimination problem was studied, the immunized animals required fewer trials to learn the reversal than the controls. Animals immunized with hen egg albumin behaved like animals injected with saline solution. The results suggest that species-specific antigens play as important a role as brain-specific antigens in the brain cells responsible for memory and learning.