Control of abnormal electrical cavity with applied electrical fields

Electrical fields applied to the cerebellum and the hippocampus have been shown to modulate the excitability of neurons provided that the electrical field is properly oriented with the dendritic structure. The effect of electrical fields has been tested on epileptiform electrical activity in order to determine the feasibility of blocking or reducing this type of abnormal neuronal firing. The experiments were done using the hippocampal slice in-vitro preparation, since it allows direct visual control of the position of the electrodes in order to align the electrical field with the dendrites. Epileptiform electrical activity was generated by adding 3500 units/ml of penicillin to the artificial cerebrospinal fluid solution. Low-intensity electrical fields were then applied with a monopolar or a tripolar electrode using constant current pulses. It is shown that it is possible to achieve a reduction in the amplitude of the electrical activity greater than 80%. Preliminary results have confirmed that neuronal firing is decreased by the applied fields.<>