Hippocampal GABA transporter distribution in patients with temporal lobe epilepsy and hippocampal sclerosis

O. Schijns*, Ü. Karaca, P. Andrade, L. de Nijs, B. Küsters, A. Peeters, J. Dings, H. Pannek, A. Ebner, K. Rijkers, G. Hoogland

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Purpose: To determine hippocampal expression of neuronal GABA-transporter (GAT-1) and glial GABAtransporter (GAT-3) in patients with temporal lobe epilepsy (TLE) and hippocampal sclerosis (HS). Methods: Hippocampal sections were immunohistochemically stained for GABA-transporter 1 and GABA-transporter-3, followed by quantification of the immunoreactivity in the hilus by optical density measurements. GABA-transporter 3 positive hilar cells were counted and GABA-transporter protein expression in sections that included all hippocampal subfields was quantified by Western blot. Results: The hilar GABA-transporter 1 expression of patients with severe hippocampal sclerosis was about 7% lower compared to that in the mild hippocampal sclerosis/control group (p <0.001). The hilar GABA-transporter 3 expression was about 5% lower in the severe hippocampal sclerosis group than in the mild hippocampal sclerosis/control group (non-significant). Also, severe hippocampal sclerosis samples contained 34% less (non-significant) GABA-transporter 3 positive cells compared to that of controls. Protein expression as assessed by Western blot showed that GABA-transporter 1 was equally expressed in mild and severe bippocampal sclerosis samples, whereas GABA-transporter 3 was reduced by about 62% in severe hippocampal sclerosis samples (p <0.0001). Conclusion: These data confirm that GABA-transporter expression is spatially and isoform-specific reduced and GABA-transporter 3 positive cell numbers are unchanged in hippocampal sclerosis. Implications for the use of GABAergic antiepileptic therapies in hippocampal sclerosis vs non-hippocampal sclerosis patients remain to be studied.
Original languageEnglish
Pages (from-to)39-44
JournalJournal of Chemical Neuroanatomy
Publication statusPublished - 1 Jan 2015

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