Continuous bilateral infusion of GABA in the dorsomedian nucleus of the thalamus elevates the generalized seizure threshold in amygdala-kindled rats.

Abstract

In order to assess the role of continuous intracerebral infusion of GABA over the propagation of generalized seizures from the amygdala, Wistar rats were subjected to a kindling procedure at the left basolateral amygdala. Subsequently, they were implanted with miniosmotic pumps filled with 100mg/mL of GABA in saline, connected to catheters whose tips were placed bilaterally at both dorsomedian nuclei of the thalamus (DMNT). The threshold intensity to provoke local afterdischarges (ADT) and generalized seizures (GST) were measured before, during and after GABA infusion, as well as seizure intensity and signs of ataxia and sedation. While there was no observed variation on ADT, the median GST was significantly increased during, but not after infusion of GABA (P=0.047, compared to the preinfusion value). Seizure intensity was not changed. No signs of neurologic side effects were recorded. These data emphasize the role of DMNT in the generalization of seizures originated at the amygdala.