Photodynamic therapy (PDT) is used for selective destruction of cells, in particular, for treatment of brain tumors. However, photodynamic treatment damages not only tumor cells, but also healthy neurons and glial cells. To study the possible role of NF-kappa B in photodynamic injury of neurons and glial cells, we investigated the combined effect of photodynamic treatment and NF-kappa B modulators: activator betulinic acid, or inhibitors parthenolide and CAPE on an isolated crayfish stretch receptor consisting of a single neuron surrounded by glial cells. A laser diode (670 nm, 0.4 W/cm2) was used as a light source. The inhibition of NF-kappa B during PDT increased the duration of neuron firing and glial necrosis and decreased neuron necrosis and glial apoptosis. The activation of NF-kappa B during PDT increased neuron necrosis and glial apoptosis and decreased glial necrosis. The difference between the effects of NF-kappa B modulators on photosensitized neurons and glial cells indicates the difference in NF-kappa B-mediated signaling pathways in these cell types. Thus, NF-kappa B is involved in PDT-induced shortening of neuron firing, neuronal and glial necrosis, and apoptosis of glial cells.
