Neuronal activity in chronic ferric chloride epileptic foci in cats and monkey.

The firing patterns of neurons surrounding sites of ferric chloride (FeCl3) injection were studied in 6 cats and 1 Macaca mulatta monkey. Although a few neurons fired in poorly structured bursts similar to what has been described for some neurons in alumina foci in monkeys, no well-formed bursts were recorded. In addition, EEG spikes were not recorded chronically in two cats, nor were EEG spikes recorded during corticography. We could not confirm the reliability of this preparation in cats as a model of chronic epilepsy.