Fig. 4: Effects of therapeutic STN DBS on intracellular Ca2+ levels in STN neurons and afferent presynaptic terminals and local glutamate and GABA release in unilateral 6-OHDA-lesioned PD mice.
From: Differential synaptic depression mediates the therapeutic effect of deep brain stimulation
a, Timeline: unilateral AAV injection followed by ipsilateral 6-OHDA injection and hybrid probe implantation, fiber photometry recording and rotation tests in Vglut2-cre mice. b, DAB staining of TH+ cells in the midbrain of unilateral 6-OHDA-lesioned Vglut2-cre mice. Scale bars, 500 µm. c,d, Rotation tests to compare the number of spontaneous rotations before and during STN DBS (130 Hz, 60-µs pulse width, 150 µA) in sham-lesioned (c) and 6-OHDA-lesioned (d) Vglut2-cre mice. *P < 0.05, **P < 0.01, ****P < 0.0001, ##P < 0.01, ###P < 0.001, ####P < 0.0001 (for c: Baseline-Contralateral versus DBS-Contralateral, P = 0.0040; DBS-Ipsilateral versus DBS-Contralateral, P = 0.0001; for d: Baseline-Ipsilateral versus DBS-Ipsilateral, P = 0.0342; Baseline-Contralateral versus DBS-Contralateral, P < 0.0001; Baseline-Ipsilateral versus Baseline-Contralateral, P < 0.0001; DBS-Ipsilateral versus DBS-Contralateral, P = 0.0056), two-way ANOVA followed by Tukey’s multiple comparisons test. All data are plotted as mean ± s.e.m. n = 9 mice for sham-lesioned group, n = 14 mice for 6-OHDA-lesioned group, including both males and females. See Supplementary Videos 1 and 2 for representative behavioral videos. e,h,k, Schematic illustrations showing the microinjection of AAVs to express GCaMP6f with tdTomato in STN neurons (e), GCaMP7f in the afferent terminals in the STN and tdTomato in STN neurons (h) and SF-Venus-iGluSnFR.S72A, iGABASnFR.F102G and tdTomato in STN neurons (k). f,i,l, Time-lapsed fluorescence ratio (normalized to the baseline before the first DBS stimulation) of GCaMP6f/tdTomato in STN neurons (f), presynaptic GCaMP7f/postsynaptic tdTomato in the STN (i) and SF-Venus- iGluSnFR.S72A/tdTomato and iGABASnFR.F102G/tdTomato recorded simultaneously in the STN (l). g,j, Summary of DBS-induced changes in cytosolic Ca2+ levels in STN neurons (g) and afferent terminals in the STN (j) at different stimulation intensities. *P < 0.05, **P < 0.01, ***P < 0.001 (for g: 100 µA versus 150 µA, P = 0.0018; 150 µA versus 200 µA, P = 0.0006; for j: 100 µA versus 150 µA, P = 0.0032; 150 µA versus 200 µA, P = 0.0248), n = 8 mice for postsynaptic group (g) and n = 6 mice for presynaptic group (j), including both males and females, repeated one-way ANOVA followed by Dunnett’s multiple comparisons test. m, Comparison of DBS-induced changes between glutamate and GABA release at different stimulation intensities, recorded from mice co-expressing SF-Venus-iGluSnFR.S72A, iGABASnFR.F102G and tdTomato. *P < 0.05, **P < 0.01 (100 µA: P = 0.0028, 150 µA: P = 0.0282, 200 µA: P = 0.0083), n = 6 mice, including both males and females, paired two tailed t-test. NS, not significant.
