A new approach to the reactive afterdischarge in the development of kindling.

Simultaneously recorded multielectrode EEG data obtained during the course of amygdaloid kindling in cats were quantitatively analyzed by means of a multidimensional autoregressive model. By the use of this method, the afterdischarge was objectively separated into propagated and reactive discharge respectively in the frequency domain and it permitted the study of the progressive development of reactive afterdischarge which has been suggested to have a functional relationship with seizure development. As a result, marked augmentation and a tendency for synchronization of reactive afterdischarge were noted in the midbrain reticular formation and anteroventral part of the thalamus along with seizure development. Furthermore, a remarkable contribution to producing afterdischarges at other brain sites was revealed. Such contribution of the reticular system as a pacemaker was also shown by analysis of the background EEG. From the above findings obtained in kindling preparation of cats through multidimensional autoregressive analysis, a new approach to the mechanism of kindling phenomenon was demonstrated and a possible mechanism was also discussed.