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. 2020 Nov 27;9:e61591. doi: 10.7554/eLife.61591

Figure 6. Dopamine neuron stimulation induces progressive changes in reach-to-grasp kinematics.

(A) The average maximum reach extent progressively decreased across sessions with ‘during reach’ stimulation. Linear mixed model: effect of laser: t(62) = 1.70, p=0.09; interaction between laser and session: t(585) = 6.88, p=1.59×10−11. Average maximum reach extent returned to baseline within the first ‘occlusion’ session. Contrast testing (‘retraining’ session 10 vs. ‘occlusion’ session 1): t(585) = 1.62, p=0.11. (B) Same as (A) for ‘between reach’ stimulation. Linear mixed model: effect of laser: t(62) = 0.02, p=0.99; interaction between laser and session: t(585) = −0.43, p=0.67. (C) Same as (A) and (B) for ‘during reach’ illumination in control EYFP-injected rats. Linear mixed model: effect of laser: t(62) = 0.10, p=0.92; interaction between laser and session: t(585) = −0.68, p=0.50. Figure 6—figure supplement 1 shows the relationship between reach extent and fiber tip location for these groups. (D) Moving average of maximum reach extent within the last ‘retraining’ session, first 6 ‘laser on’ sessions, and first 5 ‘occlusion’ sessions. Black bars represent trials with a statistically significant difference between groups (Wilcoxon rank sum test, p<0.01). (E) Average grasp aperture at reach end for ‘during reach’ stimulation. Linear mixed model: effect of laser: t(48) = −1.34, p=0.19; interaction between laser and session: t(585) = −2.19, p=0.03. Average aperture returned to baseline within the first ‘occlusion’ session. Contrast testing (‘retraining’ session 10 vs. ‘occlusion’ session 1): t(585) = −0.87, p=0.38. (F) Moving average of aperture at reach end within the last ‘retraining’ session, first 6 ‘laser on’ sessions, and first 4 ‘occlusion’ sessions. (G) Same as (E) for paw orientation. Linear mixed model: effect of laser: t(74) = −2.52, p=0.01; interaction between laser and session: t(585) = 0.19, p=0.85. Average angle returned to baseline within the first ‘occlusion’ session. Contrast testing (‘retraining’ session 10 vs. ‘occlusion’ session 1): t(585) = 1.64, p=0.10. (H) Moving average of paw angle at reach end across trials in the last (10th) ‘retraining’ session, first 6 ‘laser on’ sessions, and first 4 ‘occlusion’ sessions. (I) Same as (E) and (G) for maximum reach velocity. Linear mixed model: effect of laser: t(49) = −0.45, p=0.65; interaction between laser and session: t(585) = −2.45, p=0.01. Average velocity returned to baseline within the first ‘occlusion’ session. Contrast testing (‘retraining’ session 10 vs. ‘occlusion’ session 1): t(585) = −1.64, p=0.10. (J) Moving average of maximum reach velocity within the last ‘retraining’ session, first 6 ‘laser on’ sessions, and first 4 ‘occlusion’ sessions. ‘R10’, ‘L1’, ‘O1’, etc. indicate the 10th retraining session, first ‘laser on’ session, first ‘occlusion’ session, etc. Shaded colored areas in D, F, H, J and error bars in A, B, C, E, I represent s.e.m. Similar data for ChR2 Between rats are shown in Figure 6—figure supplement 2. Individual rat data are shown in Figure 6—figure supplements 3–6. Figure 6—figure supplement 7 compares kinematic measures (final zdigit2, aperture, paw orientation, and maximum reach velocity) between successful and unsuccessful reaches for ChR2 during, ChR2 between, and EYFP rats. Figure 6—figure supplement 8 shows success rate and kinematic measures as a function of final zdigit2 for ChR2 during, ChR2 between, and EYFP rats. * indicates p<0.05 for the laser or laser-session interaction terms in panels E, G, I. *** indicates p<1.0×10−10 for the laser-session interaction term in panel A.

Figure 6—source data 1. A .mat file containing maximum reach extent of digit2 (mean_dig2_endPt), aperture at reach end (mean_end_aperture), paw orientation at reach end (mean_end_orientations), and mean paw velocity (mean_pd_v) for 22 testing sessions (‘retraining’, ‘laser on’, and ‘occluded’).
Data is average per session for each rat. The field ‘experimentInfo’ provides information on groups.
Figure 6—source data 2. A .mat file containing digit2 endpoint (digEnd), aperture at reach end (aperture), orientation at reach end (orientation), and velocity (velocity) averages across a moving block of 10 trials for 22 testing sessions (‘retraining’, ‘laser on’, and ‘occluded’).
The field ‘exptInfo’ provides information on groups.
Figure 6—source data 3. Statistics.
A .xlsx file containing the statistical output of Wilcoxon ranksum tests for comparisons between ChR2 During and EYFP group averages in Figures 6D, F, H and J.

Figure 6.

Figure 6—figure supplement 1. Maximum reach extent on laser day 10 as a function of anterior-posterior, medial-lateral, and dorsal-ventral fiber tip coordinates referenced to bregma (A–P and M–L) or brain surface (D–V).

Figure 6—figure supplement 1.

The same symbol represents the same rat across panels within each group. r and p values are for linear regressions fit to each plot. Bold r and p-values indicate p<0.05. (A) ‘ChR2 during’ group. Note posteromedial sites tended to have stronger effects, although this may have been driven by one subject. (B) ‘ChR2 between’ group. (C) ‘EYFP’ group.
Figure 6—figure supplement 1—source data 1. A .mat file containing digit2 endpoints (mean_dig2_endPt) for 22 testing sessions (‘retraining’, ‘laser on’, and ‘occluded’).
Data is average per session for each rat. The field ‘experimentInfo’ provides information on groups.
Figure 6—figure supplement 1—source data 2. A .xlsx file containing the estimated fiber tip locations for each rat in all groups.
Virus 1 = 'ChR2 During'; Virus 2 = 'ChR2 Between'; Virus 3 = 'Arch During'; Virus 4 = 'Arch Between'; Virus 5 = 'EYFP'.
Figure 6—figure supplement 2. Reach-to-grasp kinematics do not change in EYFP control rats or ChR2-injected rats receiving between reach stimulation.

Figure 6—figure supplement 2.

(A) Average grasp aperture in EYFP control rats. Gray lines represent individual rats. Linear mixed model: effect of laser: t(48) = −0.16, p=0.88; interaction between laser and session: t(585) = −1.14, p=0.26. (B) Same as (A) but for paw orientation. Linear mixed model: effect of laser: t(75) = −0.65, p=0.52; interaction between laser and session: t(585) = 0.47, p=0.64. (C) Same as (A) and (B) but for maximum reach velocity. Linear mixed model: effect of laser: t(49) = −0.23, p=0.82; interaction between laser and session: t(585) = 0.72, p=0.47. (D) Moving average of maximum reach extent for ‘between reach’ stimulation within the last ‘retraining’ session, first 6 ‘laser on’ sessions, and first 5 ‘occlusion’ sessions. Black bars represent trials with a statistically significant difference between groups (Wilcoxon rank sum test, p<0.01). Data for ‘during reach’ stimulation from Figure 6D are shown for comparison. (E) Average grasp aperture for ‘between reach’ stimulation. Linear mixed model: effect of laser: t(48) = −0.60, p=0.55; interaction between laser and session: t(585) = 2.59, p=9.76×10−3. (F) Moving average of aperture at grasp end within the last ‘retraining’ session, first 6 ‘laser on’ sessions, and first 4 ‘occlusion’ sessions. Black bars represent trials with a statistically significant difference between groups (Wilcoxon rank sum test, p<0.01). (G) Same as (E) for paw orientation. Linear mixed model: effect of laser: t(74) = −0.67, p=0.51; interaction between laser and session: t(585) = 1.85, p=0.06. (H) Moving average of paw angle at grasp end within the last ‘retraining’ session, first 6 ‘laser on’ sessions, and first 4 ‘occlusion’ sessions. Black bars represent trials with a statistically significant difference between groups (Wilcoxon rank sum test, p<0.01). (I) Same as (E) and (G) for maximum reach velocity. Linear mixed model: effect of laser: t(49) = 0.17, p=0.87; interaction between laser and session: t(585) = −0.43, p=0.67. (J) Moving average of maximum reach velocity within the last ‘retraining’ session, first 6 ‘laser on’ sessions, and first 4 ‘occlusion’ sessions. ‘R10’, ‘L1’, ‘O1’, etc. indicate the 10th retraining session, first ‘laser on’ session, first ‘occlusion’ session, etc. Shaded colored areas in D, F, H, J and error bars in A, B, C, E, G, I represent s.e.m. ** indicates p<0.01 for the laser-session interaction term in panel E.
Figure 6—figure supplement 2—source data 1. A .mat file containing aperture at reach end (mean_end_aperture), paw orientation at reach end (mean_end_orientations), and mean paw velocity (mean_pd_v) for 22 testing sessions (‘retraining’, ‘laser on’, and ‘occluded’).
Data is average per session for each rat. The field ‘experimentInfo’ provides information on groups.
Figure 6—figure supplement 2—source data 2. A .xlsx file containing the estimated fiber tip locations for each rat in all groups.
Virus 1 = ‘ChR2 During’; Virus 2 = ‘ChR2 Between’; Virus 3 = ‘Arch During’; Virus 4 = ‘Arch Between’; Virus 5 = ‘EYFP’.
Figure 6—figure supplement 2—source data 3. Statistics.
A .xlsx file containing the statistical output of Wilcoxon ranksum tests for comparisons between ChR2 During and ChR2 Between group averages in Figure 6—figure supplement 2 panels D, F, H, and J.
Figure 6—figure supplement 3. Individual rat data for moving average of maximum reach extent across trials within individual sessions (‘ChR2 During’, ‘ChR2 Between’ and ‘EYFP’).

Figure 6—figure supplement 3.

Each colored line represents the same rat across panels. ‘R10’, ‘L1’, ‘O1’, etc. indicate the 10th retraining session, first ‘laser on’ session, first ‘occlusion’ session, etc.
Figure 6—figure supplement 3—source data 1. A .mat file containing digit2 endpoint (digEnd) averages across a moving block of 10 trials for 22 testing sessions (‘retraining’, ‘laser on’, and ‘occluded’).
The field ‘exptInfo’ provides information on groups.
Figure 6—figure supplement 4. Individual rat data for moving average of grasp aperture across trials within individual sessions (‘ChR2 During’, ‘ChR2 Between’ and ‘EYFP’).

Figure 6—figure supplement 4.

Each colored line represents the same rat across panels. ‘R10’, ‘L1’, ‘O1’, etc. indicate the 10th retraining session, first ‘laser on’ session, first ‘occlusion’ session, etc.
Figure 6—figure supplement 4—source data 1. A .mat file containing aperture at reach end averages across a moving block of 10 trials for 22 testing sessions (‘retraining’, ‘laser on’, and ‘occluded’).
The field ‘exptInfo’ provides information on groups.
Figure 6—figure supplement 5. Individual rat data for moving average of paw angle across trials within individual sessions (‘ChR2 During’, ‘ChR2 Between’ and ‘EYFP’).

Figure 6—figure supplement 5.

Each colored line represents the same rat across panels. ‘R10’, ‘L1’, ‘O1’, etc. indicate the 10th retraining session, first ‘laser on’ session, first ‘occlusion’ session, etc.
Figure 6—figure supplement 5—source data 1. A .mat file containing orientation at reach end averages across a moving block of 10 trials for 22 testing sessions (‘retraining’, ‘laser on’, and ‘occluded’).
The field ‘exptInfo’ provides information on groups.
Figure 6—figure supplement 6. Individual rat data for moving average of maximum reach velocity across trials within individual sessions (‘ChR2 During’, ‘ChR2 Between’ and ‘EYFP’).

Figure 6—figure supplement 6.

Each colored line represents the same rat across panels.
Figure 6—figure supplement 6—source data 1. A .mat file containing reach velocity averages across a moving block of 10 trials for 22 testing sessions (‘retraining’, ‘laser on’, and ‘occluded’).
The field ‘exptInfo’ provides information on groups.
Figure 6—figure supplement 7. Kinematic measures separated by reach success or failure for ChR2 During (left column), ChR2 Between (middle column), and EYFP (right column) groups.

Figure 6—figure supplement 7.

(A) Average maximum reach extent. Maximum reach extent was significantly shorter for failed reaches than successful reaches with stimulation during reaches (linear mixed model: interaction between laser and outcome: t(1188) = 0.54, p=0.59; interaction between session, laser, and outcome: t(1189) = −3.20, p=1.41×10−3). There was no significant difference in maximum reach extent by outcome during ‘Laser On’ sessions for ChR2 between (interaction between laser and outcome: t(1188) = 0.70, p=0.48; interaction between session, laser, and outcome: t(1188) = 0.26, p=0.79) or EYFP groups (interaction between laser and outcome: t(1188) = −0.91, p=0.36; interaction between session, laser, and outcome: t(1188) = 0.74, p=0.46). (B) Same as (A) for aperture at the end of the reach. Aperture was significantly smaller for failed reaches than successful reaches with stimulation during reaches (interaction between laser and outcome: t(1166) = 0.04, p=0.97; interaction between session, laser, and outcome: t(1176) = 2.05, p=0.04). There was no significant difference in aperture by outcome during ‘Laser On’ sessions for ChR2 between (interaction between laser and outcome: t(1163) = −0.71, p=0.48; interaction between session, laser, and outcome: t(1164) = 0.30, p=0.77) or EYFP groups (interaction between laser and outcome: t(1163) = 1.08, p=0.28; interaction between session, laser, and outcome: t(1163) = −0.55, p=0.58). (C) Same as (A) for reach orientation at the end of the reach. There was no significant difference in paw orientation by outcome during ‘Laser On’ sessions for ChR2 During (interaction between laser and outcome: t(1185) = 1.81, p=0.07; interaction between session, laser, and outcome: t(1190) = −1.46, p=0.14), ChR2 Between (interaction between laser and outcome: t(1184) = 1.24, p=0.21; interaction between session, laser, and outcome: t(1185) = −1.19, p=0.23), or EYFP groups (interaction between laser and outcome: t(1184) = −0.80, p=0.42; interaction between session, laser, and outcome: t(1184) = 0.92, p=0.36). (D) Same as (A) for maximum reach velocity. Velocity was significantly smaller for failed reaches than successful reaches with stimulation during reaches (interaction between laser and outcome: t(1188) = 0.04, p=0.97; interaction between session, laser, and outcome: t(1191) = 2.22, p=0.03). There was no significant difference in velocity by outcome during ‘Laser On’ sessions for ChR2 between (interaction between laser and outcome: t(1187) = 0.48, p=0.63; interaction between session, laser, and outcome: t(1187) = −0.83, p=0.41) or EYFP groups (interaction between laser and outcome: t(1187) = −0.66, p=0.51; interaction between session, laser, and outcome: t(1187) = 0.93, p=0.35). * indicates p<0.05 and ** indicates p<0.01 in the linear mixed model.
Figure 6—figure supplement 7—source data 1. A .mat file containing digit2 endpoint (mean_dig2_endPt_z), aperture at reach end (mean_end_aperture), orientation at reach end (mean_end_orientation), and reach velocity (mean_pd_v) separated by trial outcome.
Each column is a different outcome type, which are specified in the field ‘outcomeNames’ (e.g. column two is first reach success).
Figure 6—figure supplement 8. Differences between reaches matched for reach extent in the ChR2 during (left column), ChR2 between (middle column), and EYFP (right column) groups.

Figure 6—figure supplement 8.

(A) Average number of trials per session with different reach extents in each group. Note skew towards shorter reaches in ChR2 during, ‘laser on’ sessions. Only reaches past the pellet were included in this analysis since shorter reaches cannot be successful. (B) Average success rate as a function of reach extent across groups. Even for extent-matched reaches, ChR2 during rats are less successful during ‘laser on’ compared to ‘occlusion’ sessions. (C) Same as (B) for aperture at reach end. (D) Same as (B) and (C) for paw orientation at reach end. * indicates p<0.05, ** indicates p<0.01, and *** indicates p<0.001 for comparisons between laser on and retraining (paired t-tests). # indicates p<0.05, ## indicates p<0.01, and ### indicates p<0.001 for comparisons between laser on and occluded (paired t-tests).
Figure 6—figure supplement 8—source data 1. A .mat file containing digit2 endpoint (digEnd), aperture at reach end (aperture), orientation at reach end (orient), and trial outcomes (outcome) for all trials across all sessions for each rat.
The field ‘experimentInfo’ provides information on groups.
Figure 6—figure supplement 8—source data 2. Statistics.
A .xlsx file containing statistical output for paired t-test comparisons between ‘laser on’ and ‘retraining’ sessions and between ‘laser on’ and ‘occluded’ sessions for ChR2 During, ChR2 Between, and EYFP groups. ‘Z Block’ is the 10 groups of trials stratified by their maximum zdigit2 extent.