Effect of intra-amygdala injection of lipopolysaccharide on kindling epileptogenesis in adult rats.

BACKGROUND Contribution of neuroinflammation and epilepsy in the mature brain has elicited contradictory results with either excitatory or inhibitory effects. The amygdala is one of the main parts of the limbic system susceptible to insults that lead to neuroinflammation and epilepsy. This study evaluates the effect of chronic inflammation of the rat amygdala induced by lipopolysaccharide (LPS) on kindling epileptogenesis. METHODS LPS (5µg/rat) was infused once daily into the basolateral amygdala (BLA) of adult rats. Daily electrical stimulation (150 - 300 µA, 100 Hz, monophasic square wave stimulus of 1 msec per wave, 2 sec duration) was delivered into BLA 30 min after LPS injections until the animals became fully kindled. RESULTS LPS had no significant effect on the development of focal and generalized seizures. CONCLUSION The type of neural system exposed to LPS and its specific electrophysiological properties seems to ascertain the final excitatory or inhibitory outcome.