Figure 4
Locomotion dynamics and correspondence to the overall corticosterone level in the head-fixed animals. (a–c) Locomotion parameters in the 25-day protocol; daily averages calculated with a resolution of seconds; the solid orange lines correspond to the grand averages; data analyzed with the Friedman test followed by mean ranks comparison and Dunn’s correction. (a) Absolute movement time stabilized at about 20% after some initial fluctuations but no statistically significant effect of time (Fr = 30.86, p = 0.1578). (b, c) Significant effect of time in both the total distance traveled (Fr = 49.81, p = 0.0015) and in the maximum velocity (Fr = 96.18, p < 0.0001). Longer distance traveled and higher maximum velocity on day 1 (D1), drop on D2 and steady increase between D2 and D25 in both as well: D1 vs. D2 (*p = 0.0382 and *p = 0.0289, respectively); D2 vs. D25 (*p = 0.0382 and ****p < 0.0001, respectively). (d–f) Correlation between the blood corticosterone concentration and the locomotion parameters. Corticosterone level measured every 5 days during the 25-day head-fixed habituation protocol. Locomotion parameters presented as averages for the head-fixed sessions in-between blood sampling (e.g. day 2–5, day 6–10, etc.). (d) No statistically significant correlation between the blood corticosterone and the absolute movement time (r = 0.00788, p = 0.9615). (e) Statistically significant correlation between blood corticosterone and the total distance traveled (r = – 0.4715, **p = 0.0021). Outliers identified (black filled squares at 386.025, 566.660 and 574.568 m), but included in data analysis (removal would not change the statistical outcome). (f) No statistically significant correlation between blood corticosterone and the maximum velocity (r = − 0.2781, p = 0.0823). (g–i) Correlation between the blood corticosterone and the locomotion parameters from the first day of the head-fixed habituation (omitted in the analysis presented in d–f). No statistically significant correlation between the corticosterone and the absolute movement time, the total distance traveled and the maximum velocity (r = − 0.3863, p = 0.3446; r = 0.1144, p = 0.7873; r = − 0.6839, p = 0.0614, respectively). Comparisons in (d, e) made with the Spearman’s correlation analysis and in (f–i) with the Pearson’s correlation analysis; n = 8.
