Nitric oxide spatial distribution in single cultured hippocampus neurons: investigation by projection of...

Recent studies have revealed a non-homogeneous distribution of nitric oxide synthase (NOS) in neurons. However, it is not yet clear whether the intracellular distribution of NOS represents the intracellular nitric oxide (NO) distribution. In the present study, software developed in our laboratory was applied to the reconstructed image obtained from confocal slice images in order to project the 3-D reconstructed images in any direction and to cut the neuron in different sections. This enabled the spatial distribution of NO to be visualized in any direction and section. In single neurons, NO distribution was seen to be heterogeneous. After stimulation with glutamate, the spatial changes in different areas of the neuron were different. These findings are consistent with immunocytochemical data on the intracellular localization of nNOS in hippocampus neurons, and will help to elucidate the specificity of nitric oxide signaling. Finally, the administration of SNAP and L-NAME was used to examine DAF-2 distribution in the neurons. The results showed this distribution to be homogenous; therefore, it did not account for the NO distribution results.