Figure 2.

Acupuncture induces calcium transients in S1 neurons.

(A) Top, schematic diagram showing the acupoints ST36 (Zusanli) and GB34 (Yanglingquan), and non-acupoint in adjacent sites as the sham control group; bottom, transfection sites (arrow) of GCaMP6s in S1. Scale bar: 500 μm. (B) Pseudo-colored images reflecting calcium intensity of neurons in selected field of view from S1 under resting state and during acupuncture. Scale bar: 50 μm. (C–K) Time-series records of normalized calcium values (in ΔF/F₀) during the period of repeated acupuncture stimuli (grey shaded box). The temporal scale (x-axis) was presented in seconds. Three acupuncture courses (20 seconds each) were sequentially applied, with a 30-second resting interval between two treatments. In each group, calcium activities from representative fields of view were normalized and averaged for plotting. Fields of view numbers: n = 10 for C; n = 8 for D, K; n = 3 for E–G, J; n = 6 for H–I. Animal numbers: n = 3 each. (L) Comparison of total integrated neuronal calcium activity during the acupuncture course. Data are expressed as mean ± SEM and were analyzed by one-way analysis of variance. Group effect: F_{(8, 41)} = 20.10, P < 0.001, Bonferroni’s multiple comparison test: **P < 0.01. cNS: Needle stimulation on the contralateral side; GCaMP6s: green fluorescent-calmodulin protein 6s; iNS: needle stimulation on the ipsilateral side; M1: primary motor cortex; NS: needle stimulation; S1: primary somatosensory cortex.