Nitric oxide (NO) in brain: - detection by voltammetric methods - role in a rat model of absence epilepsy

The multiplicity of the functional aspects in which nitric oxide (NO) is involved, is now well documented. As yet, however, only a limited number of studies deal with a direct detection of NO in vivo. In the present paper, a procedure allowing such measurement by mean of a carbon fiber sensor coated with porphyrin-nickel and nafion is detailed. The effects of a NOS inhibitor and a NO donor on the cortical NO signal of the Wistar rat are also reported. In this respect, the disappearance of the signal observed after inhibition of the NO-synthase (L-ANA) as well as its increase after the administration of a NO donor (SIN-1) support that the signal measured at a 650 mV potential is NO dependent. Finally, the results obtained in using the NO sensor in GAERS rats (Genetic Absence Epileptic Rat from Strasbourg, an animal model for absence epilepsy) are briefly summarised. Data obtained indicate that NO exerts an antiepileptic role in facilitating paradoxical sleep. It is concluded that the NO sensor prepared can be efficiently used in vivo in physiological and pathophysiological situations.