NADPH- diaphorase activity in temporal lobe cortex of refractory epilepsy subjects who underwent epilepsy surgery

D`ALESSIO L, LÓPEZ-COSTA JJ, KONOPKA H, CONSALVO D, SEOANE E, LÓPEZ EM, GUELMAN L, KOCHEN S, ZIEHER L.

San Diego

Congreso; Annual Meeting of the American Epilepsy Society; 2006

American Epilepsy Society

Nitric oxide (NO) is a short lived free radical with diverse functions as a biological messenger molecule, and has been implicated in numerous aspects of the physiology and pathology of the CNS including epilepsy. NO can acts as anticonvulsant or proconvulsant depending on the experimental model and the pharmacological parameters used. There is little information about changes in NO levels in human epileptic brains. Neurons containing nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) synthesizes NO. The aim of this study is to investigate the anatomical distribution, morphology, optical density and cell sizes of NADPH-d neurons in the temporal cortex of patients with hippocampal sclerosis who underwent anterior temporal lobectomy for intractable temporal lobe seizures. Methods: Brain samples of 7 X 5  x 5 mm from temporal cortex were obtained from 7 patients was compared with 5 postmortem control samples. Samples were immediately fixed and incubated at 37ºC in 1mg/ml of B-NADPH and 0,2 mg/ml of nitroblue tetrazolio. NADPH d activity was measured as distribution of formazan deposits (endproduct of the histochemical reaction). Neuronal area and neuropil staining optical density was determined. Results Sprouting (dendritic arborization) and larger NADPH-d positive neurons, with an increase in staining intensity were found in epileptic´s temporal cortex (p<0.05). Conclusions The increased area and the observed morphological changes in NADPH-d reactive cells found in this study indicate plastic changes and suggest an up-regulation in NO system in the neocortex. These changes could contribute to abnormal cortical excitability however, could also be involved in adaptative neuroprotective function.   Key words. Epilepsy surgery. Temporal cortex. NADPH diaphorase. Sprouting. Nitric oxide Key words. Epilepsy surgery. Temporal cortex. NADPH diaphorase. Sprouting. Nitric oxide