Epilepsia experimental en pequeños animales

This work includes the chronic implantation of a nine electrode plug, on the skull of small animals, which had previously been treated as follows: one mi of aluminum oxide placed on the right anterior cerebral cortex. A pollyethylene tube was sometimes placed on each cerebral cortex to permit intracraneal drug administration. E. E.G. recordings were made with unrestrained animals. 1. In the cortical area where the alumina had placed, an initial decrease in voltage was observed during the first four days. Four days later desynchronization of the background electrical activity increased voltage and localization of the primary focus were observed. 2. In the period from eight to twelve days after the alumina application, the animals developed an increased of voltage in the corresponding area of the contra lateral hemisphere. This corresponded to the development of a secondary or mirror" focus which was fully developed in about two days. its discharge at first depended on the primary focus but became independent in 10 to 15 days. 3. Two to three months after the alumina application, the electrical activity in the primary focus began to decrease and had disappeared almost completely after four months. 4. Any studies for the purpose of observing changes in electrical activity of the primary focus, should be done within the first three months after alumina application. On the other hand the secondary focus continues to fire for at least one year