Figure 1
From: Chronic BDNF simultaneously inhibits and unmasks superficial dorsal horn neuronal activity
BDNF-induced fluctuations of [Ca2+]I in superficial dorsal horn neurons. (A1–A3) Example recording [Ca2+]i fluctuations sampled in a SDH neuron and the processing steps used by the FIBSI event-detection program. The running median (red line in A1, window = ~ 5 s) was calculated based on the raw amplitude (AU) and time coordinate data, then the peaks below the running median were traced to form a reference line (red line in A2), and then the Ramer–Douglas–Peucker algorithm detected waveforms above the reference (red x at event peaks). (B) Left: Examples of [Ca2+]i activity detected by FIBSI in 3 different neurons. Right: The proportion of ‘silent’ neurons in the BDNF-treatment condition was significantly reduced compared to the naïve condition. Proportions were compared using a Fisher exact test. (C, D) Violin plots of the log-transformed values for fluctuation amplitude and AUC. Fluctuation amplitudes and AUC were significantly increased in naïve and BDNF-treated neurons compared to the ‘silent’ neurons, while both measures in the BDNF-treated neurons were significantly reduced compared to naïve. Neurons sampled: ‘silent’ n = 20 (849 fluctuations), naïve n = 78 (2651 fluctuations), and BDNF n = 57 (1555 fluctuations). Median with quartiles shown. Comparisons made using Brown-Forsythe and Welch’s ANOVA tests and Games-Howell post-hoc test. (E) Relative frequency (%) of the fluctuations binned by amplitude. Amplitude values were normalized to the largest fluctuation in each neuron. (F–G) The mean fluctuation amplitude and AUC in the naïve and BDNF-treated neurons were significantly increased compared to the ‘silent’ neurons. (H–J) Further analysis revealed little to no effect of BDNF on fluctuation duration or frequency, but the fluctuations in ‘silent’ neurons exhibited longer rise times. For scatterplots F–J, the fluctuations that were < 10% the maximal fluctuation amplitude in each neuron were omitted to reduce the effects of low-amplitude noise. Scatterplots in F–J show the median with the interquartile range. All comparisons of medians in F–K were made using Kruskal–Wallis tests and Dunn’s post-hoc test. **P < 0.01, ***P < 0.001, ****P < 0.0001.
