Extended Data Fig. 2: Ex-vivo mouse colonic motility sensing and stimulation.
From: High-density soft bioelectronic fibres for multimodal sensing and stimulation
a, Schematic structure of the sensing-stimulation regions of S-NeuroString which included 8 piezoresistive sensors (labeled as S1-S8, 0.5 cm distance between sensors) and 4 stimulation electrodes (labeled as SE1-SE4, 1 cm distance between electrodes). b, A schematic illustration of the stimulation study, beginning with a 5-min baseline period, followed by five biphasic stimulation trials (2 V vs AgCl reference electrode, applied simultaneously to all stimulation channels). Each stimulation trial consisted of 50 msec stimulation pulses (1.5 mA) and lasted for 5 s and followed by recovery time (no stimulation) for 55 s. c, Output of piezoresistive sensors before and during electrical stimulation of the tissue (1.5 mA, 100 Hz). All traces are normalized and shifted for clarity (see methods). S1 and S5 were broken. d, Time course of the motility index obtained by different piezoresistive sensor (S2, S4, S6, S8) before and during tissue stimulation (n = 5 colons/mice). Error bars indicate SD. e, Summary of motility index values before and during stimulation, which is calculated from the output of the different sensors (n = 5 mice). Boxes represent the interquartile range, spanning from the 25th to the 75th percentile of the data. Squares represent the mean. Whiskers represent the outlier (coefficient of 1.5). P values: 0.053, 0.015, 0.003, 0.012, 0.049, and 0.007 for S2, S3, S4, S6, S7, and S8, respectively. ns p > 0.05; * p ≤ 0.05; ** p ≤ 0.01; *** p ≤ 0.001; paired, two-tailed Student’s t-test. f, Overlay of sensor output and measured diameter as a function of time. Dashed lines mark the beginning of stimulation. S4 and S6 are located at X4 and X6, respectively. A clear change in diameter is observed with each stimulation. g, Frequency of slow wave and CMMC events before and during stimulation. Each data point is the average of 8 different locations on the colon (n = 5 mice). Bars represent the mean. Error bars indicate SE. Although no statistical significance was observed between the no-stimulation and stimulation groups, a clear trend toward increased frequency with stimulation was evident. Additional repetitions, longer recordings, or more frequent stimulation may be required to achieve statistical significance.
