Fig. 2: Two-photon imaging of DS ACh transients show reward-related signals.
From: Spatially heterogeneous acetylcholine dynamics in the striatum promote behavioral flexibility
a Schematic of experimental procedure. Sagittal section adapted from atlas image87. b Left, example histology (coronal section) showing immuno-enhanced iAChSnFR sensor expression and the track from GRIN lens. Similar results were obtained in n = 10 other brains. Slice is projected onto a corresponding atlas image87. D, dorsal; V, ventral; M, medial; L, lateral; LV, lateral ventricle. Scale bar, 1 mm. Right, mean fluorescence projection image from a representative field-of-view. Note diffuse expression of iAChSnFR on somata and neuropil. Differences in apparent feature size across panels reflect varying zoom levels. Scale bar, 50 μm. c Top, mean fluorescence traces (n = 13 slices from 4 mice) showing changes in iAChSnFR responses aligned to ACh puff in the presence of ACSF (dark green) and the acetylcholinesterase (AChE) inhibitor neostigmine (light green). Shaded regions, S.E.M. Bath application of neostigmine (50 µM) blunts the ACh signal, confirming that the sensor is reporting changes in ACh fluorescence. Bottom, quantification of peak ACh signals (two-tailed, paired t test, P = 0.0001). d Mean ΔF/F traces (green) for each of 6 equal-sized quadrats ( ~ 50 × 50 µm) on a representative pseudocolor image (right). Similar results were obtained in 10 other mice. Note the heterogeneous ACh signals in response to example trials (R/NR). Mean (full field) is shown in black (bottom). Water drop denotes reward delivery. Scale bar, 50 μm. e Example iAChSnFR signals (z-scored ΔF/F) aligned to trial outcomes (reward, purple; no reward, green) for a representative mouse (left) and averaged across all 11 mice (right; reward trials = 291, no-reward, 134). Shaded regions, S.E.M. (Bottom) Heatmaps of mean normalized responses to R and NR outcomes. f, g Box plot showing the distribution of ACh responses (z-score) during outcome period (f) (significant difference between conditions, two-tailed, paired t test, 1.65 × 10−5), and latency of outcome-evoked ACh dips (g) (two-tailed, paired t test, P = 0.03) across all mice (n = 11). In box plots, center lines depict the median, box limits represent the 25th and 75th percentiles, and whiskers, data range. Source data are provided as a Source Data file.
