sk3  (Cytek Biosciences)

Journal: bioRxiv

Article Title: SK2/3 CHANNELS COUPLE WITH T-TYPE CA 2+ CHANNELS TO GATE SPINAL LOCOMOTOR RHYTHM GENERATION

doi: 10.64898/2026.03.19.712770

Figure Lengend Snippet: a-c Voltage traces from ventromedial interneurons of the rhythmogenic CPG region (L1-L2) recorded under control conditions ( a ), after tamapin application (10 nM, b ), or after lei-dab7 application (10 nM, c ). d Bar graph showing the proportion of interneurons displaying bursting in response to increasing concentrations of lei-dab7 (teal) or tamapin (purple). e Representative action potentials evoked by near-threshold current injections under control conditions (black), tamapin (purple), or lei-dab7 (teal). f-h Raincloud plots with box-and-whisker overlays (median, interquartile range) quantifying AHP amplitude ( f ), AHP duration ( g ), and firing frequency ( h ) under the three conditions. i-k Raincloud plots with box-and-whisker overlays (median, interquartile range) quantifying burst duration ( i ), amplitude ( j ), and frequency ( k ) across interneurons treated with apamin (pink), tamapin (purple), or lei-dab7 (teal). l-o Representative voltage traces from interneurons expressing control shRNA ( l ) or SK3-targeting shRNA ( m-o ), showing heterogeneous bursting phenotypes: bursts at rest/rheobase ( m ), bursts requiring stronger depolarization ( n ), and elliptic bursting dynamics ( o ). p-r Raincloud plots comparing burst duration ( p ), amplitude ( q ), and frequency ( r ) in interneurons after SK3 knockdown (orange) and after apamin application (pink). Numbers in parentheses denote recorded cells; each dot represents a single cell. Data points plotted beyond the dashed vertical line indicate values outside the axis range. n.s., not significant; * P < 0.05; ** P < 0.01; *** P < 0.001 (two-sided Fisher’s exact test for d ; Kruskal-Wallis with Dunn’s post hoc test versus control for f-h and i-k ; two-sided Mann-Whitney test for p-r ). For detailed P values, see Source Data.

Article Snippet: Equal amounts of protein (40 μg per lane) were separated on 4-15% gradient SDS-PAGE stain-free gels (Bio-Rad), transferred to nitrocellulose membranes, and probed overnight at 4 °C with either a polyclonal rabbit anti-SK3 antibody (1:500, Alomone Labs, APC-025) or an anti-actin antibody (1:1,000, A2066, Sigma-Aldrich) in Tris-buffered saline containing 5% fat-free milk.

Techniques: Control, Whisker Assay, Expressing, shRNA, Knockdown, Single Cell, MANN-WHITNEY, Patch Clamp

Journal: bioRxiv

Article Title: SK2/3 CHANNELS COUPLE WITH T-TYPE CA 2+ CHANNELS TO GATE SPINAL LOCOMOTOR RHYTHM GENERATION

doi: 10.64898/2026.03.19.712770

Figure Lengend Snippet: a Representative low-magnification confocal image of GFP-expressing Hb9 interneurons in the ventromedial spinal cord. The asterisk marks the soma of an identified interneuron. The central canal (cc) is indicated by the dashed line. Scale bar, 25 µm. b High-magnification images of the soma indicated in a , showing GFP fluorescence (top), SK2 immunolabeling (middle), and a merged GFP/SK2 overlay (bottom). Dashed lines delineate the somatic membrane. Scale bar, 10 µm. c-d Raincloud plots with box-and-whisker overlays (median, interquartile range) quantifying the size ( c ) and density ( d , clusters per µm 2 ) of SK2, SK3, and co-localized SK2/3 clusters at the somatic membrane. e Confocal images of an Hb9 interneuron soma showing GFP (left), SK3 immunolabeling (middle), and a merged GFP/SK3 overlay (right). Dashed lines delineate the somatic membrane. Scale bar, 20 µm. f Confocal images of an intracellularly recorded HB9 interneuron filled with biocytin (magenta), showing GFP immunofluorescence (green), SK2 (red), and SK3 immunolabeling (cyan), alongside a merged GFP/SK3 signal. Scale bar, 20 µm. g-h Raincloud plots with box-and-whisker overlays (median, interquartile range) quantifying the size ( g ) and density ( h ) of SK2, SK3, and co-localized clusters along the dendrites. Numbers in parentheses denote the number of cells ( c, d ) or dendrites ( g, h ) analyzed; each dot represents a single measurement. *** P < 0.001 (two-sided unpaired t-test for c and g ; One-way ANOVA for d and h ). For detailed P values, see Source data.

Article Snippet: Equal amounts of protein (40 μg per lane) were separated on 4-15% gradient SDS-PAGE stain-free gels (Bio-Rad), transferred to nitrocellulose membranes, and probed overnight at 4 °C with either a polyclonal rabbit anti-SK3 antibody (1:500, Alomone Labs, APC-025) or an anti-actin antibody (1:1,000, A2066, Sigma-Aldrich) in Tris-buffered saline containing 5% fat-free milk.

Techniques: Confocal, Expressing, Fluorescence, Immunolabeling, Membrane, Whisker Assay, Immunofluorescence

Journal: Frontiers in Pharmacology

Article Title: Compensatory attenuation of cortical apoptosis by SK2 downregulation following ketamine anesthesia

doi: 10.3389/fphar.2026.1761187

Figure Lengend Snippet: Apamin-sensitive SK2 channel-mediated mAHP currents may be linked to changes in neuronal spike frequency and adaptation at 24 h post-ketamine anesthesia. (A,B) Representative traces (A) and amplitudes (B) of the mAHP currents, treatment conditions as indicated. S1 slices from control (Ctrl) and ketamine-treated (Ket) rats were separately incubated and perfused with apamin (100 nM) or its vehicle. 22–25 neurons from 7–10 rats were used per condition. (C) Plots of spike frequency vs. current injected for layer II/III pyramidal neurons of S1. The significant differences in the spike frequency between the Ctrl and Ket groups (Ctrl: Vehicle vs. Ket: Vehicle, 80 pA, 100 pA and 110 pA, P < 0.01; 90 pA, P < 0.001) were eliminated after apamin treatment (Ctrl: Apamin vs. Ket: Apamin, P > 0.05). 20–22 neurons from 7–9 rats were recorded per condition. (D,E) Spikes in S1 layer II/III pyramidal neurons evoked for 3 s, 80 pA current injection (D) , and the adaptation index (E) was obtained by the algorithm mentioned above. 18–20 neurons from 7–9 rats were recorded per condition. (F) Quantitative analysis of SK1-3 mRNA in S1 of P8 rats. 5 rats were used per condition. P > 0.05. (G,H) Immunoblots and quantitative analysis of total (G) and membrane-bound (H) SK1-3 levels in S1 of ketamine-treated rats, normalized to corresponding levels in control rats. 8–12 rats were used per condition. * P < 0.05, ** P < 0.01, *** P < 0.001; n.s ., not significant. Data were analyzed using the Mann-Whitney U test for (F,H) and unpaired two-tailed Student’s t-tests for the other panels. Data are shown as the mean ± SEM.

Article Snippet: The following primary antibodies were used: SK1 (1:500, Alomone Labs, Cat# APC-039), SK2 (1:500, Alomone Labs, Cat# APC-028), SK3 (1:500, Alomone Labs, Cat# APC-025), β-actin (1:1,000, Millipore, Cat# A1978 ), and pan-cadherin (1:1,000, Sigma-Aldrich, Cat# SAB4500001 ).

Techniques: Anesthesia, Control, Incubation, Injection, Analysis, Western Blot, Membrane, MANN-WHITNEY, Two Tailed Test, Patch Clamp, Real-time Polymerase Chain Reaction