Fig. 3: Electrical, cellular, and biochemical changes in the pMN population after injury. | Nature Communications

Fig. 3: Electrical, cellular, and biochemical changes in the pMN population after injury.

From: Neuroprotective gap-junction-mediated bystander transformations in the adult zebrafish spinal cord after injury

Fig. 3

a Repetitive firing pattern in response to depolarizing ramp-induced and current steps-induced firing. The solid color traces show the pMN response at the rheobase and faint traces at 120% of the rheobase. b Representative sample of 5 pMNs per experimental group and analysis of the firing adaptation index. c The resting membrane potential (RMP), input resistance (Rinput), and rheobase of the recorded pMNs. d Functional calcium imaging of retrogradely traced spinal motoneurons (green) with the calcium indicator Green-1 Dextran. e Representative traces of pMN spontaneous activity in control and after injury (3 dpi). Quantification and analysis of the recorded events’ frequency and amplitude. f Fluorometric recordings and analysis of calcium transients’ amplitude following a local electrical stimulation of the spinal cord with 10 pulses (1 Hz). g Functional calcium imaging traces after a local electrical stimulation of the spinal cord with 15 pulses (30 Hz), and quantification of the calcium transient amplitude and recovery time. h Fluorescent images (single-plane) after loading with cell-permeant calcium-sensitive dye Oregon Green BAPTA-1 AM. Quantification of the resting signal intensity of the pMNs. Primary MN resting calcium intensity is independent of the soma size. i Normalized intensity and analysis of immunolabelled pMNs with calcium-binding proteins CR from uninjured (control) and injured animals. Normalizations of the arbitrary units were performed for CR calcium-binding protein to the highest obtained intensity value. j Calb2a mRNA expression (Green) in pMNs (DAPI; Blue). Quantification and analysis of the average normalized intensity and puncta of Calb2a in pMNs per animal. Asterisks and dashed white lines indicate the pMN cell bodies. AP action potential, CDF cumulative distribution (frequency), CR calretinin, DAPI 4′,6-diamidino-2-phenylindole (nuclear staining), dpi days post-injury, Rheo rheobase, Rinput input resistance, RMP resting membrane potential, SCI spinal cord injury. Data are presented as violin plots and as box plots showing the median with 25/75 percentile (box and line) and minimum–maximum (whiskers). **P < 0.01; ***P < 0.001; ****P < 0.0001; ns, not significant. For detailed statistics, see Supplementary Table 1. Source data are provided as a Source Data file.

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