Figure 8.

Glutamate (Glut) induced changes in neuronal NADPH, ATP, and glucose uptake. Cerebellar granule neurons plated on Willco dishes were exposed to glutamate/glycine (100 μm/10 μm) continuously (dashed line) or for 5 min (solid line) before termination of NMDA receptor activation with MK-801 (10 μm). A, B, NADPH autofluorescence was monitored over time (A) and at selected time points (0, 10, and 60 min; B) chosen before, during, and after glutamate excitation for statistical analysis. (At least 5 cells were analyzed per experiment, and the experiment was repeated in three different cultures. ^#p < 0.01; *p < 0.01, difference from respective control.) C, Cerebellar granule neurons plated in 24-well plates were exposed to glutamate/glycine (100 μm/10 μm) for 5 min or continuously, and their ATP content was measured (moles ATP/μg protein) at the times indicated. Data are represented as percentage of control response (n = 3 experiments in triplicate; ^#p < 0.01; *p < 0.01, difference from respective control). D, Cerebellar granule neurons plated in 96-well plates were exposed to glutamate/glycine (100 μm/10 μm) for 10 min and washed, and the medium was replaced with buffer containing ³H-2-deoxyglucose for 20 min. The cells were washed twice, and the ³H-2-deoxyglucose was measured in a Matrix-96 beta counter for 20 min. Data are presented as counts per minute (CPM) for control (washed neurons) and glutamate-treated neurons (6 wells were examined per condition per experiment and repeated in 3 separate cultures; *p < 0.01). Error bars indicate SEM.