Figure 2.

Apoptosis of YAC128 MSNs is induced by synergistic actions of dopamine and glutamate. A, MSNs (14 DIV) from the WT and YAC128 mice were exposed to a range of dopamine (Dop.) concentrations (0–500 μm) for 8 h, fixed, permeabilized, and analyzed by TUNEL staining (green) and propidium iodide counterstaining (red). B, The same experiment described in A was performed in the presence of 25 μm glutamate. C, D, The fraction of TUNEL-positive nuclei (shown in A and B) was determined and plotted against dopamine concentration for WT (open circles) and YAC128 (filled circles) MSNs. At each dopamine concentration, the data are shown as mean ± SD (n = 4–6 microscopic fields, 200–300 MSNs per field). Similar results have been obtained with six WT and YAC128 MSN cultures.