Injection of embryonic median ganglionic eminence cells or fibroblasts within the amygdala in rats kindled from the piriform cortex

Abstract

Intracerebral infusion of anticonvulsant agent secreting cells has proven to raise the threshold for seizure generation in epileptogenic areas. Median ganglionic eminence (MGE) is the main embryonic region where future GABAergic cells originate. Here we report the results of intraamygdaline grafting of MGE cells versus fibroblasts in a piriform cortex kindling model of epilepsy in the rat. Rats were implanted with an electrode in the left piriform cortex and subjected to infusion at the left basolateral amygdala of cells obtained from the MGE of embryos or fibroblasts. Some of the donor cells were obtained from transgenic rats expressing the green fluorescent protein (GFP). Seizure and neurologic behavior were recorded, and inmunohistochemical and ultrastructural studies were carried out. Cells obtained from the embryonic MGE elevated both the afterdischarge and the seizure threshold progressively, being significant 3 weeks after their injection. On the contrary, fibroblasts injected into the amygdala raised the seizure thresholds the first week, the effect weaning during the following weeks. Fibroblasts and MGE cells were shown at the injected amygdala. No behavioral side effects were recorded in either experimental group. MGE cells implanted at the amygdala may control the focal component of temporolimbic seizures. This effect may be mediated by local release of GABA.