[Effect of nitric oxide release on epileptiform discharge in CA1 area of hippocampal slices]

Using a nitric oxide (NO)-sensitive platinum microelectrode (SNM) modified with chitosan nickel (II) complex and Nafion (Nafion-CTS (Ni)-Pt), we observed the effect of nitric oxide synthase (NOS) inhibitor 7-nitro-indazole (7-NI) and N omega-nitro-L-arginine (L-NNA) on penicillin-treated hippocampal slices by simultaneously recording the stimulus-evoked field potentials and nitric oxide release from CA1 pyramidal neurons. Our results show: (1) The linear relationship range and detection limit of SNM were 4.5 x 10(-4)-1.0 x 10(-8) mol/L and 5.0 x 10(-8) mol/L respectively. (2) Penicillin (PEN) could elevate NO release, the number and amplitude of stimulus-evoked field potentials spike (SEPS) in concentration-dependent manner; (3) Both 7-NI and L-NNA depressed NO release and partly reversed the effect of penicillin. The above findings suggest that convulsant provoking effect of NO could be inhibited by NOS inhibitors. The NO-sensitive electrode may provide an useful tool for continuous detection of NO in biological tissues.