Fig. 2: 40 kHz ultrasound exposure increased neuronal activity at the somatosensory (SC) cortex in vivo in a parameter-dependent manner.

a Illustration of the experimental setup, the window surgery, electrode implantation and the placement of ultrasound transducer. b An example full field Ca²⁺ signal (ΔF/F) before, during and after 50% duty cycle 250 ms tone burst duration (TBD) ultrasound exposure, averaged across 20-s duration. Note that only a subset of cells (arrowhead indicated) responded. c Heatmaps showing Ca²⁺ signals of the average of top ten responsive cells in each trial in ΔF/F. Each row is a trial. d Traces of the mean Ca²⁺ signal for each parameter set in the heatmap, which demonstrates a clear parameter-dependent relationship between ultrasound parameters and neuronal responses. (n trial number, N animal number). e Statistical summary of area under the curve (AUC) of Ca²⁺ signals during ultrasound exposure for each parameter set. Kruskal–Wallis test revealed significant group difference among parameters (P < 0.005). Dunn’s multiple comparison test showed non-significantly larger AUC for both 500 µs and 250 ms 50% duty cycle, and significantly larger AUC for continuous wave (CW) group (P < 0.001). f Local field potential (LFP) changes at high-gamma (64–100 Hz) frequency band during ultrasound exposure. One-way ANOVA indicated significant group difference among parameters (P < 0.05). Dunnett’s multiple comparison showed significant increase in high-gamma oscillations for 10% 250 ms group and non-significant increase for 50% 250 ms exposure (data in (e, f) are expressed as mean ± SEM, and each dot represents each trial. n trial number, N animal number).