Inhibition of NMDA receptor by MK 801 prevents HgCl
-induced disruption of neuronal network and degradation of cytoskeleton components. To evaluate the protective effect of MK 801 on HgCl2-induced neurotoxicity, cells were grown for about 10 days and allowed to extend neurites and form network. Cultures were then maintained in the following conditions: control (A), 25 μM of HgCl2 (B), 25 μM of HgCl2 and 5–10 μM of MK 801 (C), and MK 801 alone (D). Phase contrast images were taken 16–24 hr later. Cells were subsequently fixed and stained with antibodies against β-tubulin and F-actin (E-H). Neurons exposed to HgCl2 exhibited retraction of neurite processes (B) and lower fluorescence intensity of β-tubulin (F) as compared with control cultures (A &E). HgCl2 in the presence of MK 801 failed to induce disturbance of network integrity and cytoskeleton staining (C &G). MK 801 alone did not affect neuronal network and fluorescence intensity of cytoskeleton staining (D &H). Scale bars, 25 μm.