[(3)H]Tiagabine binding to GABA transporter-1 (GAT-1) in suicidal depression.

BACKGROUND

In depressive disorders, alterations of GABA concentrations and number of postsynaptic GABA related receptor binding sites, as well as antidepressant effects exerted by GABA agonists, suggest a pathogenetic involvement of the GABA system.

METHOD

The binding of the presynaptic GABA ligand [(3)H]tiagabine to GABA transporter-1 (GAT-1) was studied in post mortem human frontal cortex and cingulate gyrus from 13 suicide victims and 19 controls without known neurological or psychiatric disorder.

RESULTS

No differences were found between the suicide victims and the controls with regard to the number of [(3)H]tiagabine binding sites (B(max)) or apparent affinity (K(d)).

LIMITATIONS

The study was limited to two brain regions.

CONCLUSION

Findings in other studies of alterations in the GABA system in depression seem according to the present results not to be associated with significant changes in the GABA uptake binding sites in the regions investigated.