Article Figures & Data
Figures
- Figure 1.
Light activation of rat striatal cholinergic interneurons evokes striatal dopamine release. A, ChR2-eYFP detected in striatum (left) and PPN/LDT (right) after AAV2 injection to PPN/LDT (lower), and detected in striatum only after injection to striatum (upper), fixed tissue. B, GFP-immunopositive soma after striatal injection were co-immunopositive for ChAT. C, E, Mean profiles of [DA]o ± SEM versus time evoked by 1 or 4 pulses (25 Hz) of electrical (C) or light (E) stimulation, in control drug-free conditions or in the presence of DHβE (1 μm). Data are normalized to 1p peak [DA]o in control conditions. Control conditions (black lines), DHβE (red lines). D, F, Mean peak [DA]o normalized to control 1p for electrical (D) and light-evoked DA release (F) in control (black) and in the presence of DHβE (red). n = 3 rats, n = 4 sites. Two-way ANOVA with Sidak posttest comparisons of control versus DHβE: *p < 0.05, ***p < 0.001.
- Figure 2.
Light activation of striatal cholinergic brainstem afferents with brief stimuli does not reveal dopamine release. A, Left, cartoon indicating PPN/LDT injections sites, and right, recording site labeled with red FluoSpheres in an area of cholinergic brainstem innervation indicated by ChR2-eYFP fluorescence. B, Example profiles of [DA]o (μm) versus time evoked by either light activation of ChIs (ChI ChR2, blue dashed, 1p), electrical stimulation of striatum (black solid line, 1p), or light activation of brainstem cholinergic afferents (brainstem ChR2, blue solid line, 10p 10 Hz). Inset, corresponding voltammograms for DA following each activation type for site indicated in A, at time point indicated on profiles by gray circles. C, Peak evoked [DA]o (μm) for each recording site and stimulation methods, with mean ± SEM indicated. Arrows indicate data points and sites shown in B. D, Mean profiles of current detected at DA oxidation potential (± SEM) versus time evoked by striatal electrical stimulation (1p; black) or light stimulation of ChR2-expressing cholinergic brainstem afferents (10p 10 Hz; blue) in the presence of cocaine (5 μm; n = 10 observations from 3 sites).
- Figure 3.
Light activation of striatal cholinergic interneurons but not brainstem afferents readily modulates dopamine release. A, C, Mean profiles of [DA]o ± SEM versus time evoked by 1 or 4 pulses (100 Hz) of electrical (E) stimulation alone (left), or with stimulation with light (10p/10 Hz beginning 0.5 s before electrical; right) to stimulate ChR2 expressed in either ChIs (A) or brainstem afferents (C). Data are normalized to 1p control (without light). B, D, Summary data showing mean peak [DA]o ± SEM evoked by the electrical stimulation normalized to control 1p, for ChR2-expressing ChIs (B) or brainstem afferents (D) with and without light activation (blue versus black). Two-way ANOVA with repeated measures with Sidak posttest comparisons of 1p versus 4p: **p < 0.01; N.S., p > 0.05. E, Ratio of [DA]o evoked by 4 versus 1 electrical pulses (100 Hz) with and without light stimulation (blue versus black) of either ChIs or striatal brainstem afferents. Light pre-stimulation of ChIs but not brainstem afferents significantly potentiated 4p:1p ratio of electrically evoked DA release (2-way ANOVA; Sidak posttest for with versus without light: ChI: t18 = 4.1, **p < 0.01; brainstem: t18 = 0.58, p > 0.05). F, Mean peak 1p [DA]o ± SEM, evoked by 0.7 mA and 0.3 mA electrical stimuli, with and without light prestimulation of brainstem afferents. Two-way ANOVA; Sidak posttest with versus without light: 0.7 mA: t12 = 0.29, p > 0.05; 0.3 mA: t12 = 1.2, p > 0.05. Data are in μm, n = 4 rats, n = 6 sites.
Tables
Location Data structure Type of test Power a Normal 2-way ANOVA with Sidak posttest Interaction: F1,11 = 8.5, p = 0.014; post hoc test: 1p vs 4p DHβE, p < 0.05 b Normal 2-way ANOVA Interaction: F1,6 = 17.1, p = 0.006; post hoc test: 1p vs 4p, p < 0.05 c Normal 2-way ANOVA (repeated measures) Effect of light: F1,4 = 0.19, p = 0.68; pre-flash × pulse number interaction, F1,4 = 0.02, p = 0.88 d Normal 2-way ANOVA Effect of region: F1,18 = 8.7, p = 0.004; posttest, with vs without prepulse: ChIs, p < 0.01 e Normal 2-way ANOVA Effect of light: F1,12 = 0.2, p = 0.67
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