Fig. 4.
900 Hz stimulation reduces metabolic activity with high spatial precision. (A) Schematic of PET experiments showing freely behaving mice injected with ∼400 µCi [18F] FDG (i.p.) and stimulated every 3 min for 30 min during the radiotracer uptake period. Mice were then anesthetized and scanned for 20 min. (B) Voxel-wise analysis using statistical parametric mapping showing significant within-subject cluster differences between stimulated and unstimulated hemispheres. Voxel-wise comparisons with a probabilistic threshold-free cluster enhancement correction (29) were run with preestablished thresholds indicating a statistically significant (n = 5 animals, t4 = 8.61, P = 0.001, k > 100) decrease in activity over the stimulated area. (C) Lowering statistical threshold (t4 = 4.60, P = 0.01, k > 100) reveals incorporation of broader hippocampal coverage and extended networks (red arrow).