Doublecortin immunoreactivity in dentate gyrus of epileptic patients who underwent epilepsy surgery.

D`ALESSIO L, KONOPKA H, LÓPEZ EM, CONSALVO D, KAUFFMAN M, KOCHEN S, LÓPEZ-COSTA JJ.

Buzios

Congreso; Congreso Latinoamericano de Neurociencias; 2008

Sociedad Brasilera de Neurociencias y Comportamiento

Objectives: Doublecortin (DCX) is a microtubule-associated phosphoprotein involved in neuronal development. In adult neurogenesis newly generated cells express DCX, which has been associated with neurite elongation and synaptogenesis. DCX has been used as a marker of newly born neurons in the adult dentate gyrus (DG). In epilepsy, the role of neurogenesis is controversial and only a few reports determined DCX in epileptic tissue. The aim of this study was to study DCX immunoreactivity in dentate gyrus of human hippocampal sclerosis from patients who underwent epilepsy surgery for intractable temporal lobe epilepsy (TLE). Methods: Hippocampal sections of 6 patients with hippocampal sclerosis and intractable (refractory) TLE, who underwent therapeutic surgery, were processed using Immunofluorescence and Immunoperoxidase for DCX. Archival material from normal post-mortem hippocampus were simultaneously processed. Staining intensity of neurons expressing DCX was determined by computarized image analysis. Results: In both control and epileptic hippocampus, DCX immunoreactive (DCX-IR) neurons were found in DG of hippocampus, showing areas with heavy DCX expression. Lower staining intensity was observed in DG of epileptic hippocampus compared with normal hippocampus (transmittance 72, 8 ±4 / 66, 7 ±1; p<0.05). Cell dispersion of DCX-IR neurons in granular cell layer was found in epileptic tissue. Also longer apical dendrites and slender irregular somas were observed in epileptic GD. Conclusions: Lower DCX expression, cell dispersion of DCX-IR neurons in granular layer and longer apical dendrites were observed in DG of hippocampal sclerosis. These findings could indicate plastic changes related to epileptic activity in this area. Similar observations determined in experimental models of epilepsy, were related to immature synapses and synapses reorganization.  Peruilh Fellowship, CONICET PIP5785, PICT START UP