Changes in oscillatory activity of neurons in the medial septal area in animals with a model of chronic temporal epilepsy

Comparative studies of the activity of extracellularly recorded neurons in living slices of the medial septal area of healthy guinea pigs and animals with a model of chronic temporal epilepsy demonstrated differences between them in terms of the frequency and pattern of cell discharges. The brains of animals with experimental epilepsy showed a doubling of the total level of activity as compared with controls, due to increases in the discharge frequencies of irregular and regular non-volleying neurons. There was a sharp (three-fold) increase in the number of cells with rhythmic discharge volleys, along with changes in the parameters of volley activity — both in neurons with the endogenous (pacemaker) pattern and in cells with secondary involvement in rhythmic activity. The possible mechanisms for these changes are discussed. These data widen our understanding of the processes forming pathological synchronization in epilepsy and may assist in the creation of new approaches to the treatment of this disease. __________ Translated from Zhurnal Vysshei Nervnoi Deyatel'nosti imeni I. P. Pavlova, Vol. 57, No. 5, pp. 618–623, September–October, 2007.