The role of TNF-α in amygdala kindled rats

Abstract

In the present study, the interaction between epileptogenesis and the immune system were studied in a kindling model. First, the effects of a single administration of TNF-α (5.0 µg/kg, i.p.) on seizure and EEG activity were investigated in amygdala-kindled rats. TNF-α treated rats showed more prolonged epileptiformic discharges than control rats. TNF-α also induced a decrease in the power of Ꮄ band and an increase in θ and α activity. In addition, a marked increase in the power of β and ɣ band was observed. The EEG changes were most numerous in the frontal cortex and amygdala. All effects were registered 24 h after TNF-α administration. Finally, electrical stimulation enhanced the level of TNF-α in blood serum from 1.9 ±1.5 to 12.7 ±3.8 pg/ml and in brain tissue 56.8 ±6.0 to 109.2 ±6.0 pg/mg, as was determined via the ELISA method. It can be concluded that there is a mutual facilitative interaction of both epileptogenic and cytokine-derived mechanisms on this type of seizure. The changes in the power spectrum of the EEG after TNF-α might contribute to intensify thalamic-derived facilitation of epileptic discharge in cortical structures. © 2002 Elsevier Science Ireland Ltd and the Japan Neuroscience Society. All rights reserved.