[Learning dysfunction model in ddY mouse and IgG].

Mice of the ddy strain having once received an electric shock in the dark chamber of a passive avoidance response unit were divided into two groups according to their behavior pattern. It is suggested that learning function of the mice which did not avoid the dark chamber (negative-avoidance mice: N-mice) was disturbed. After an injection of IgG obtained from the positive-avoidance mice (P-mice) into the N-mice, these prior N-mice displayed the behavior pattern similar to that of P-mice following an application of electric shock. It was found that the sugar chain structure of N-mouse IgG was different from that of P-mouse IgG. This result indicates that the sugar chain structure is related to the learning ability of ddy mice.