Calretinin immunoreactivity was quantitatively evaluated and the density of calretinin + neuronal profiles was quantified. Brain tissue from 24 patients neurosurgically treated for pharmacoresistent epilepsy was examined.
As a control, post-mortem acquired neocortical samples, of nine patients without any brain affecting disease were used. The overall density of CR+ neurons was significantly decreased in focal cortical dysplasia (FCD) type I (to 70 % of control values) and even more in FCD type II (50 % of controls).
In normal temporal neocortex resected together with sclerotic hippocampus no change compared to controls was found. in CR+ neuronal density. Our results may contribute to the better understandiung of the role of individual interneuronal populations in epileptogenesis.