Figure 6.

Changes in [Ca²⁺]_i, Δψ_m, and somatic area after NMDAR activation in striatal neurons. Representative tracings and images are from YAC128 neurons (similar responses are observed in wild-type neurons although in different proportions as shown in Fig. 7A). Neurons were challenged with 100 μm NMDA/10 μm glycine in Mg²⁺-free buffer with pyruvate instead of glucose. MK-801 (5 μm) was added after 10 min to stop NMDAR activation and allow for neuronal recovery. A, Field excerpts of a representative time sequence (0–35 min) of striatal neurons loaded with the fluo-5F (green) and equilibrated with TMRM⁺ (red). Note the different response patterns to NMDA, before and after addition of MK-801, and the variety of somatic sizes within the striatal neuronal population. B, Time sequence (0–35 min) illustrating a pair of striatal neurons with different extents of somatic swelling after NMDA challenging. C–E, Three distinct response patterns, involving changes in [Ca²⁺]_i (C), Δψ_m (D), and somatic area (E), were identified: normal recovery (blue tracings), delayed recovery (green tracings), and immediate deregulation (red tracings). See Results for a detailed description of the individual tracings.