{ "paper": "wengert-2026-kcnc1", "claims": 32, "panels": { "total": [ "fig1a", "fig1b", "fig1c", "fig1d", "fig1e", "fig1s1a", "fig1s1b", "fig1s1c", "fig1s1d", "fig1s2a", "fig1s2b", "fig1s2c", "fig1s2d", "fig1s2e", "fig2a", "fig2b", "fig2c", "fig2d", "fig2e", "fig2f", "fig2g", "fig3a", "fig3b", "fig3c", "fig3d", "fig3e", "fig3f", "fig3g", "fig3h", "fig3i", "fig3s1a", "fig3s1b", "fig3s1c", "fig3s1d", "fig3s1e", "fig4a", "fig4b", "fig4c", "fig4d", "fig4e", "fig4f", "fig4g", "fig4h", "fig4i", "fig4j", "fig4s1a", "fig4s1b", "fig4s1c", "fig4s2a", "fig4s2b", "fig4s2c", "fig4s2d", "fig4s3a", "fig4s3b", "fig4s3c", "fig5a", "fig5b", "fig5c", "fig5d", "fig5e", "fig5f", "fig5g", "fig5h", "fig5i", "fig5j", "fig5k", "fig5s1a", "fig5s1b", "fig5s1c", "fig5s1d", "fig6a", "fig6b", "fig6c", "fig6d", "fig6e", "fig6f", "fig6g", "fig6h", "fig6i", "fig6j", "fig6k", "fig6l", "fig6s1a", "fig6s1b", "fig6s1c", "fig6s1d", "fig6s1e", "fig6s1f", "fig6s1g", "fig6s1h", "fig7a", "fig7b", "fig7c", "fig7d", "fig7e", "fig7f", "fig7g", "fig7h", "fig7i", "fig7j", "fig7k", "fig8a", "fig8b", "fig8c", "fig8d", "fig8e", "fig8f", "fig8g", "fig8h", "fig8i", "fig8j", "fig8s1a", "fig8s1b", "fig8s1c", "fig8s1d", "fig8s1e", "fig8s1f", "fig8s1g", "fig8s1h", "fig9a", "fig9b", "fig9c", "table1", "table2", "keyresource" ], "orphan": [ "fig1a", "fig1b", "fig1c", "fig1d", "fig1e", "fig1s1a", "fig1s1b", "fig1s1c", "fig1s1d", "fig1s2a", "fig1s2b", "fig1s2c", "fig1s2d", "fig1s2e", "fig2a", "fig2e", "fig2f", "fig2g", "fig3a", "fig3b", "fig3c", "fig3d", "fig3e", "fig3f", "fig3g", "fig3i", "fig3s1a", "fig3s1b", "fig3s1c", "fig3s1d", "fig3s1e", "fig4a", "fig4b", "fig4c", "fig4d", "fig4f", "fig4g", "fig4h", "fig4i", "fig4j", "fig4s1a", "fig4s1b", "fig4s1c", "fig4s2a", "fig4s2b", "fig4s2c", "fig4s2d", "fig4s3a", "fig4s3b", "fig4s3c", "fig5a", "fig5h", "fig5i", "fig5j", "fig5k", "fig5s1a", "fig5s1b", "fig5s1c", "fig5s1d", "fig6a", "fig6b", "fig6c", "fig6d", "fig6e", "fig6i", "fig6j", "fig6k", "fig6l", "fig6s1a", "fig6s1b", "fig6s1c", "fig6s1d", "fig6s1e", "fig6s1f", "fig6s1g", "fig6s1h", "fig7a", "fig7b", "fig7c", "fig7d", "fig7e", "fig7i", "fig7j", "fig7k", "fig8a", "fig8e", "fig8f", "fig8i", "fig8j", "fig8s1a", "fig8s1b", "fig8s1c", "fig8s1d", "fig8s1e", "fig8s1f", "fig8s1g", "fig8s1h", "keyresource" ], "figure_level": [ "fig1", "fig1s2", "fig2", "fig3", "fig4s2", "fig4s3", "fig5s1" ], "phantom": [], "pct": 21.6 }, "statistics": { "total": 49, "orphan": [ "p=0.017", "p=0.065", "p=0.96", "p=0.055", "p=0.29", "p=0.19", "p=0.62", "p=0.49", "p=0.11", "p=0.38", "p=0.45", "p=0.35", "p=0.46", "p=0.86", "p=0.69", "p=0.47", "p=0.82", "p=0.21", "p=0.016", "p=0.60", "p=0.014", "p=0.76", "p=0.92", "p=0.39", "p=0.41", "p=0.10", "p=0.15", "p=0.092", "p=0.0805", "p=0.40", "p=0.16", "p=0.0026", "p=0.28", "p=0.87", "p=0.34", "p=0.057", "p=0.33", "p=0.52", "p=0.24", "p=0.14" ], "pct": 18.4 }, "spans": { "segmented": 512, "obligations": 233, "textual": 279, "accounted": 130, "pct": 55.8, "orphans": [ { "uid": "results-003", "section": "results", "text": "A targeting vector containing part of intron 1 followed by the coding sequence of exons 2\u20134 flanked by loxP sites was then introduced upstream of the modified endogenous sequence ( Figure 1A ).", "stats": [], "panels": [ "fig1a" ] }, { "uid": "results-004", "section": "results", "text": "Thus, in the absence of Cre recombinase, there is expression of the introduced 5\u2019 WT exons 2\u20134; in the presence of Cre recombinase, there is Cre-mediated excision of the floxed WT exons 2\u20134 coding sequence and expression of Kcnc1 harboring the c.1262C>T substitution, resulting in the single amino acid change p.Ala421Val ( Figure 1A ).", "stats": [], "panels": [ "fig1a" ] }, { "uid": "results-005", "section": "results", "text": "Sanger sequencing confirmed the knock-in missense mutation in exon 2, and subsequent PCR showed Cre-dependent genome recombination of the variant ( Figure 1B and C ).", "stats": [], "panels": [ "fig1b", "fig1a", "fig1d", "fig1c" ] }, { "uid": "results-006", "section": "results", "text": "We utilized a breeding strategy that allowed us to examine the behavior and physiology of mice expressing the Kcnc1 variant globally (via cross to Actb-Cre mice; JAX#: 003376), as is presumed the case with human patients harboring KCNC1- p. A421V as a de novo pathogenic variant ( Figure 1D ).", "stats": [], "panels": [ "fig1d" ] }, { "uid": "results-007", "section": "results", "text": "We also used a transgenic mouse line (C57BL/6-Tg(Pvalb-tdTomato)15Gfng/J; JAX#: 027395) which fluorescently labels PV-INs with the red fluorescent protein tdTomato driven by the endogenous parvalbumin promoter ( Figure 1D ).", "stats": [], "panels": [ "fig1d" ] }, { "uid": "results-011", "section": "results", "text": "( A ) Design and structure of the conditional Kcnc1 -A421V allele.", "stats": [], "panels": [ "fig1a" ] }, { "uid": "results-013", "section": "results", "text": "( B ) Sequencing results indicate successful targeting of c.1262C>T to introduce the heterozygous A421V variant.", "stats": [], "panels": [ "fig1b" ] }, { "uid": "results-014", "section": "results", "text": "( C ) PCR confirmation of two HET founders ( Kcnc1 -A421V/+) and two WT littermates. 167 bp, WT allele fragment; 207 bp, floxed allele fragment.", "stats": [], "panels": [ "fig1c" ] }, { "uid": "results-015", "section": "results", "text": "( D ) Breeding strategy to generate control and experimental mice in which the Kcnc1 -A421V variant is expressed globally and PV cells are fluorescently labeled for targeted recording.", "stats": [], "panels": [ "fig1d" ] }, { "uid": "results-017", "section": "results", "text": "Figure 1\u2014figure supplement 1. Pvalb-tdTomato reporter effectively labels parvalbumin-positive fast-spiking GABAergic inhibitory interneurons (PV-INs) in wild-type (WT) and Kcnc1 -A421V/+ mice.", "stats": [], "panels": [ "fig1s1" ] }, { "uid": "results-018", "section": "results", "text": "( A ) Representative immunohistochemistry images for parvalbumin in WT (top row) and Kcnc1 -A421V/+ (bottom row) mice (postnatal day [P]21\u201333) showing a high degree of overlap between the tdTomato reporter and parvalbumin expression.", "stats": [], "panels": [ "fig1s1a" ] }, { "uid": "results-022", "section": "results", "text": "( B ) Counts of PV cells per unit area (mm 2 ) are not different between WT and Kcnc1 -A421V/+ mice (N=3 mice/genotype).", "stats": [ "N=3" ], "panels": [ "fig1s1b" ] }, { "uid": "results-028", "section": "results", "text": "( D ).", "stats": [], "panels": [ "fig1s2d" ] }, { "uid": "results-029", "section": "results", "text": "Onset of developmental and motor benchmarks for WT (N=7) and Kcnc1 -A421V/+ (N=10) mice.", "stats": [ "N=7", "N=10" ], "panels": [] }, { "uid": "results-031", "section": "results", "text": "Counts of PV-INs per unit of neocortical area were not different between WT and Kcnc1 -A421V/+ mice (P24\u201333), indicating that expression of A421V did not alter the density of neocortical PV-INs ( Figure 1\u2014figure supplement 1A and B ), consistent with the fact that interneuron migration is complete prior to appreciable expression of Kcnc1 in mouse.", "stats": [], "panels": [ "fig1s1" ] }, { "uid": "results-032", "section": "results", "text": "We separately used immunohistochemistry to validate our genetic strategy for labeling PV-INs ( Figure 1\u2014figure supplement 1 ): The average sensitivity rates were greater than 0.8 in both groups as previously reported ( Kaiser et al., 2016 ) and were not different by genotype ( Figure 1\u2014figure supplement 1 ), with the average false-positive identification rate less than 0.1 for each group ( Figure 1\u2014figure supplement 1 ).", "stats": [], "panels": [ "fig1s1" ] }, { "uid": "results-037", "section": "results", "text": "To this end, we assessed spatial memory in juvenile Kcnc1 -A421V/+ mice in the Barnes maze task ( Figure 2A ).", "stats": [], "panels": [ "fig2a" ] }, { "uid": "results-042", "section": "results", "text": "( A ) Example pathways for wild-type (WT) (black) and Kcnc1 -A421V/+ (green) during the 4-day acquisition phase of the Barnes maze test.", "stats": [], "panels": [ "fig2a" ] }, { "uid": "results-048", "section": "results", "text": "( E ) Total number of arm entries.", "stats": [], "panels": [ "fig2e" ] }, { "uid": "results-049", "section": "results", "text": "( G ) Total distance traveled.", "stats": [], "panels": [ "fig2g" ] }, { "uid": "results-054", "section": "results", "text": "Importantly, the total number of arm entries ( Figure 2E ) and the distance traveled ( Figure 2F ) did not differ between genotypes, suggesting that the observed deficit was not due to differences in general activity, motor function, or exploratory drive.", "stats": [], "panels": [ "fig2e", "fig2f" ] }, { "uid": "results-057", "section": "results", "text": "In our recordings of HEK cells expressing WT and A421V Kv3.1 subunits, A421V was a profound loss of function, although a small magnitude K + current was detectable (which cannot be easily distinguished from the small endogenous delayed rectified potassium current present in HEK cells; Figure 3\u2014figure supplement 1 ).", "stats": [], "panels": [ "fig3s1" ] }, { "uid": "results-058", "section": "results", "text": "A 50:50 mixture of WT and A421V subunits, more approximating the clinical condition, produced K + currents that were ~42% of the magnitude and slightly shifted in the hyperpolarized direction relative to the WT condition ( Figure 3\u2014figure supplement 1D and E ).", "stats": [], "panels": [ "fig3s1" ] }, { "uid": "results-059", "section": "results", "text": "Considering that Kv3.1 channels form heterotetramers with other Kv3 channel isoforms (likely Kv3.2) in cerebral cortex PV-INs, we also sought to clarify the impact of the A421V Kcnc1 variant on native neuronal voltage-gated K + channel function in neocortical layer II-IV PV-INs, known to express high levels of Kv3.1 ( Chow et al., 1999 ), from Kcnc1 -A421V/+ mice at the juvenile timepoint of P16\u201321. The outside-out nucleated macropatch technique allowed for high-quality electrophysiological recordings of somatic voltage-gated K + currents ( Figure 3A\u2013C ).", "stats": [], "panels": [ "fig3a", "fig3b", "fig3c" ] }, { "uid": "results-062", "section": "results", "text": "We did not observe differences in the voltage dependence ( Figure 3F ) or kinetics of activation ( Figure 3G ) when comparing voltage-gated K + channel currents from WT and Kcnc1 -A421V/+ mice.", "stats": [], "panels": [ "fig3f", "fig3g" ] }, { "uid": "results-065", "section": "results", "text": "( A ) Representative image of a cell being recorded in the outside-out nucleated macropatch configuration.", "stats": [], "panels": [ "fig3a" ] }, { "uid": "results-066", "section": "results", "text": "( B\u2013C ) Example family of traces of voltage-gated K + channel currents from a PV-IN from wild-type (WT) (B, black ) and Kcnc1 -A421V/+ (C, green ) mice (postnatal day [P]16\u201321).", "stats": [], "panels": [ "fig3b", "fig3c" ] }, { "uid": "results-067", "section": "results", "text": "( D ) Average voltage-gated K + channel current density for WT (n=13 macropatches, N=3 mice) and Kcnc1 -A421V/+ (n=17, N=3 mice).", "stats": [ "n=13", "N=3", "n=17", "N=3" ], "panels": [ "fig3d" ] }, { "uid": "results-068", "section": "results", "text": "( E ) Maximum K + channel current density per PV-IN macropatch in WT and Kcnc1 -A421V/+ mice.", "stats": [], "panels": [ "fig3e" ] }, { "uid": "results-069", "section": "results", "text": "( F ) Averaged normalized plots of K + conductance relative to voltage command indicating voltage dependence of activation curves for WT and Kcnc1 -A421V/+ mice.", "stats": [], "panels": [ "fig3f" ] }, { "uid": "results-070", "section": "results", "text": "( G ) Average activation time constant for the voltage-gated K + channel currents relative to voltage command potential in both WT and Kcnc1 -A421V/+ mice.", "stats": [], "panels": [ "fig3g" ] }, { "uid": "results-076", "section": "results", "text": "( A\u2013C ) Example Kv3.1 currents in HEK cells expressing wild-type (WT) (A; black), a 50:50 mixture of WT and A421V (B; blue), and A421V ( C ; green) Kv3.1 subunits.", "stats": [], "panels": [ "fig3a", "fig3b", "fig3c" ] }, { "uid": "results-078", "section": "results", "text": "( D ) Average current density for WT (black), WT+A421V (blue), and A421V (green).", "stats": [], "panels": [ "fig3d" ] }, { "uid": "results-080", "section": "results", "text": "( E ) Average normalized conductance relative to membrane potential for WT (black), WT+A421V (blue), and A421V (green).", "stats": [], "panels": [ "fig3e" ] }, { "uid": "results-093", "section": "results", "text": "( A ) Representative images taken at \u00d710 ( left ) and \u00d740 ( right ) magnification of a layer IV neocortical PV-IN recorded in the whole-cell configuration to characterize intrinsic excitability.", "stats": [], "panels": [ "fig4a" ] }, { "uid": "results-094", "section": "results", "text": "( B\u2013C ) Representative example traces for juvenile (postnatal day [P]16\u201321) wild-type (WT) ( B , black ) and Kcnc1 -A421V/+ ( C , green ) PV-INs generating action potentials (APs) at current injections of \u2013100, 200, 300, and 400 pA.", "stats": [], "panels": [ "fig4b", "fig4c" ] }, { "uid": "results-096", "section": "results", "text": "( D ) Average relationship between PV-IN AP frequency in response to a range of current injections for juvenile WT (n=20 cells, N = 9 mice) and Kcnc1 -A421V/+ (n=36 cells, N = 12 mice).", "stats": [ "n=20", "N = 9", "n=36", "N = 12" ], "panels": [ "fig4d" ] }, { "uid": "results-098", "section": "results", "text": "(F) Representative images for a layer IV neocortical PV-IN from an adult mouse.", "stats": [], "panels": [ "fig4f" ] }, { "uid": "results-099", "section": "results", "text": "( G\u2013H ) Representative example traces displaying intrinsic excitability in adult (P32\u201342) WT and Kcnc1 -A421V/+ PV-INs.", "stats": [], "panels": [ "fig4g", "fig4h" ] }, { "uid": "results-105", "section": "results", "text": "Figure 4\u2014figure supplement 1. Intrinsic physiology of neocortical layer II-IV parvalbumin-positive fast-spiking GABAergic inhibitory interneurons (PV-INs) remains impaired when resting membrane potential is not normalized.", "stats": [], "panels": [ "fig4s1" ] }, { "uid": "results-106", "section": "results", "text": "( A\u2013B ) Representative example traces showing spiking in layer V neocortical PV-INs from wild-type (WT) (A, black) and Kcnc1 -A421V/+ ( B , green) mice in response to depolarizing current injections.", "stats": [], "panels": [ "fig4s1a", "fig4s1b" ] }, { "uid": "results-107", "section": "results", "text": "( C ) Average PV-IN spiking frequency relative to current injection.", "stats": [], "panels": [ "fig4s1c" ] }, { "uid": "results-111", "section": "results", "text": "( A ) Representative images taken at \u00d710 ( left ) and \u00d740 ( right ) magnification of a PV-positive cell in the reticular thalamus recorded in the whole-cell configuration to characterize intrinsic excitability.", "stats": [], "panels": [ "fig4s2a" ] }, { "uid": "results-112", "section": "results", "text": "( B ) Representative example traces of action potentials (APs) generated in response to current injections of varying magnitudes.", "stats": [], "panels": [ "fig4s2b" ] }, { "uid": "results-114", "section": "results", "text": "( D ) Frequency-current relationship shows impaired intrinsic excitability in the RT PV cells relative to depolarizing current injections (0\u2013400 pA).", "stats": [], "panels": [ "fig4s2d" ] }, { "uid": "results-118", "section": "results", "text": "( C ) Average frequency-current relationship for WT (n=20 cells, N = 9 mice) and Kcnc1 -A421V/+ (n=32 cells, N = 12 mice) PV-INs with uncorrected resting membrane potential.", "stats": [ "n=20", "N = 9", "n=32", "N = 12" ], "panels": [ "fig4s3c" ] }, { "uid": "results-134", "section": "results", "text": "We also recorded these cells in current clamp to characterize intrinsic excitability ( Figure 5H\u2013K ).", "stats": [], "panels": [ "fig5h" ] }, { "uid": "results-140", "section": "results", "text": "( A ) Representative image of a neocortical excitatory cell being recorded in the outside-out nucleated macropatch configuration.", "stats": [], "panels": [ "fig5a" ] }, { "uid": "results-146", "section": "results", "text": "( H ) Representative images taken at \u00d710 ( left ) and \u00d740 ( right ) magnification of a layer IV neocortical excitatory cell recorded in the whole-cell configuration to characterize intrinsic excitability.", "stats": [], "panels": [ "fig5h" ] }, { "uid": "results-148", "section": "results", "text": "( K ) Average relationship between excitatory cell AP frequency in response to a range of current injections for WT (N=23 cells, N=3 mice) and Kcnc1 -A421V/+ (n=22, N=3 mice).", "stats": [ "N=23", "N=3", "n=22", "N=3" ], "panels": [] }, { "uid": "results-151", "section": "results", "text": "( A ) Representative images taken at \u00d710 ( left ) and \u00d740 ( right ) magnification of a recorded layer IV excitatory cell.", "stats": [], "panels": [ "fig5s1a" ] }, { "uid": "results-152", "section": "results", "text": "( B\u2013C ) Representative example traces of evoked action potentials (APs) in response to depolarizing current injections in cortical layer IV excitatory neurons from wild-type (WT) ( B ) and Kcnc1 -A421V/+ ( C ) mice.", "stats": [], "panels": [ "fig5s1b", "fig5s1c" ] }, { "uid": "results-153", "section": "results", "text": "( D ) Average frequency-current relationship for WT (black; n=12, N=4) and Kcnc1 -A421V/+ (n=12, N=4) mice.", "stats": [ "n=12", "N=4", "n=12", "N=4" ], "panels": [ "fig5s1d" ] }, { "uid": "results-158", "section": "results", "text": "We collected simultaneous whole-cell patch-clamp electrophysiology recordings from one neocortical layer II-IV PV-IN and one nearby (<100 \u03bcm inter-soma distance) excitatory neuron, of which 21 of 64 (32.8%) WT neuron pairs and 15 of 43 (34.9%) Kcnc1 -A421V/+ neuron pairs exhibited unitary inhibitory postsynaptic currents (uIPSCs) in the excitatory cell in response to AP generation in the PV-IN at 5, 10, 20, 40, 80, and 120 Hz ( Figure 6A\u2013E ).", "stats": [], "panels": [ "fig6a", "fig6b", "fig6c", "fig6d", "fig6e" ] }, { "uid": "results-166", "section": "results", "text": "( A ) Representative images showing simultaneous whole-cell patch-clamp recordings of cortical PV-IN and nearby excitatory cell ( left , \u00d710 magnification; right, \u00d740 magnification).", "stats": [], "panels": [ "fig6a" ] }, { "uid": "results-167", "section": "results", "text": "( B ) Example traces of a PV-IN and excitatory cell pair in which generation of action potentials (APs) in the PV-IN (bottom trace) is sufficient to induce clear unitary inhibitory postsynaptic potentials (uIPSPs) in the excitatory cell (arrowhead, top trace).", "stats": [], "panels": [ "fig6b" ] }, { "uid": "results-169", "section": "results", "text": "( C\u2013D ) Example traces of unitary inhibitory postsynaptic currents (uIPSCs) in both wild-type (WT) ( C ) and Kcnc1 -A421V/+ pairs of synaptically connected neurons. 10 APs were generated in the PV-IN (top trace) at 40 Hz and the uIPSCs are shown below.", "stats": [], "panels": [ "fig6c", "fig6d" ] }, { "uid": "results-178", "section": "results", "text": "Figure 6\u2014figure supplement 1. Excitatory neuron to parvalbumin-positive fast-spiking GABAergic inhibitory interneuron (PV-IN) unitary excitatory synaptic neurotransmission is unaltered in juvenile (postnatal day [P]16\u201321) Kcnc1 -A421V/+ mice.", "stats": [], "panels": [ "fig6s1" ] }, { "uid": "results-179", "section": "results", "text": "( A ) Example traces of simultaneous recordings of a synaptically connected PV-IN and excitatory cell neuron pair in which generation of action potentials (APs) in the excitatory cell leads to unitary excitatory postsynaptic potentials (uEPSPs) in the PV-IN.", "stats": [], "panels": [ "fig6s1a" ] }, { "uid": "results-181", "section": "results", "text": "( B\u2013C ) Representative example traces of unitary excitatory postsynaptic currents (uEPSCs) generated in wild-type (WT) ( B ) and Kcnc1 -A421V/+ pairs of excitatory cells (top trace) and nearby PV-INs (bottom trace).", "stats": [], "panels": [ "fig6s1b", "fig6s1c" ] }, { "uid": "results-184", "section": "results", "text": "( E ) Average failure rate for WT and Kcnc1 -A421V/+ neuron pairs relative to presynaptic stimulation frequency.", "stats": [], "panels": [ "fig6s1e" ] }, { "uid": "results-185", "section": "results", "text": "( F ) Average uEPSC magnitude in response to a train of five APs generated at 20 Hz in WT and Kcnc1 -A421V/+ neuron pairs.", "stats": [], "panels": [ "fig6s1f" ] }, { "uid": "results-186", "section": "results", "text": "( G ) Paired-pulse ratio of the second uEPSC to the first uEPSC in WT and Kcnc1 -A421V/+ mice.", "stats": [], "panels": [ "fig6s1g" ] }, { "uid": "results-187", "section": "results", "text": "(H) Average synaptic latency between peak of AP to peak of uEPSC in both WT and Kcnc1 -A421V/+ mice.", "stats": [], "panels": [ "fig6s1h" ] }, { "uid": "results-188", "section": "results", "text": "In 9 of 61 neuron (14.8%) pairs for WT mice and 6 of 43 pairs (14.0%) for Kcnc1 -A421V/+ mice at P16\u201321, we observed unitary excitatory synaptic currents (uEPSCs) from the excitatory neuron onto the PV-IN, which allowed us to investigate whether there were abnormalities in excitatory neurotransmission ( Figure 6\u2014figure supplement 1A\u2013D ).", "stats": [], "panels": [ "fig6s1" ] }, { "uid": "results-189", "section": "results", "text": "The frequency-dependent rate of failure showed no significant effect for genotype ( Figure 6\u2014figure supplement 1E ).", "stats": [], "panels": [ "fig6s1" ] }, { "uid": "results-190", "section": "results", "text": "Lastly, the magnitude ( Figure 6\u2014figure supplement 1F ), paired-pulse ratio ( Figure 6\u2014figure supplement 1G ), and the latency ( Figure 6\u2014figure supplement 1H ) of the uEPSCs were not significantly different between WT and Kcnc1 -A421V/+ neuron pairs, indicating that excitatory neuron synaptic transmission onto PV-INs is not altered in juvenile Kcnc1 -A421V/+ mice.", "stats": [], "panels": [ "fig6s1" ] }, { "uid": "results-192", "section": "results", "text": "As in the younger mice, we recorded pairs of cortical PV-IN and excitatory neurons that were synaptically connected \u2013 14 of 36 pairs (38.9%) in WT mice (N = 8 mice) and 13 of 36 pairs (36.1%) in Kcnc1 -A421V/+ mice (N=8 mice; Figure 7A\u2013D ).", "stats": [ "N = 8", "N=8" ], "panels": [ "fig7a", "fig7b", "fig7c", "fig7d" ] }, { "uid": "results-193", "section": "results", "text": "We did not detect differences in failure rates between WT and Kcnc1 -A421V/+ mice over a range of stimulation frequencies ( Figure 7E ).", "stats": [], "panels": [ "fig7e" ] }, { "uid": "results-199", "section": "results", "text": "( A ) Example presynaptic cortical PV-IN and postsynaptic excitatory neuron.", "stats": [], "panels": [ "fig7a" ] }, { "uid": "results-201", "section": "results", "text": "( B\u2013C ) Example traces of unitary inhibitory postsynaptic currents (uIPSCs) in both adult wild-type (WT) ( B ) and Kcnc1 -A421V/+ ( C ) pairs of synaptically connected neurons. 10 APs were generated in the PV-IN at 40 Hz, and the evoked uIPSCs are displayed in the trace below where the black and green traces are the averages of numerous individual sweeps shown in gray.", "stats": [], "panels": [ "fig7b", "fig7c" ] }, { "uid": "results-202", "section": "results", "text": "( D ) Connection probability between WT (14 of 36, N=8 mice) and Kcnc1 -A421V/+ (13 of 36, N=8 mice) pairs PV-INs and nearby excitatory cells.", "stats": [ "N=8", "N=8" ], "panels": [ "fig7d" ] }, { "uid": "results-203", "section": "results", "text": "( E ) Average frequency-dependent rate of failure for the first five APs in adult WT and Kcnc1 -A421V/+ neuron pairs.", "stats": [], "panels": [ "fig7e" ] }, { "uid": "results-208", "section": "results", "text": "Two-photon in vivo calcium imaging reveals paroxysmal hypersynchronous discharges and altered neuronal excitability in Kcnc1 -A421V/+ mice We then utilized two-photon (2P) calcium imaging to investigate neural activity in neocortical circuits in both WT and Kcnc1 -A421V/+ mice (>P50) in layer II/III of primary somatosensory cortex in vivo ( Figure 8A ).", "stats": [], "panels": [ "fig8a" ] }, { "uid": "results-213", "section": "results", "text": "( A ) Experimental setup for in vivo 2P calcium imaging with representative calcium transients from cells expressing AAV-hSyn-GCaMP8m and mean dF/F 0 of the whole field of view (FOV) aligned to locomotion speed.", "stats": [], "panels": [ "fig8a" ] }, { "uid": "results-218", "section": "results", "text": "( E ) Experimental design for in vivo 2P calcium imaging of somata positive (PV+) and negative (PV\u2013) for parvalbumin.", "stats": [], "panels": [ "fig8e" ] }, { "uid": "results-219", "section": "results", "text": "( F ) Example calcium transients of PV+ (bottom) and PV\u2013 (top) somata aligned to locomotion speed in a WT (left) and Kcnc1 -A421V mouse (right).", "stats": [], "panels": [ "fig8f" ] }, { "uid": "results-224", "section": "results", "text": "Figure 8\u2014figure supplement 1. Analysis of in vivo two-photon calcium imaging data.", "stats": [], "panels": [ "fig8s1" ] }, { "uid": "results-225", "section": "results", "text": "( A ) PV\u2013 (wild-type [WT], n=847 cells, N=4 mice; Kcnc1 -A421V, n=901 cells, N=3 mice) and ( B ) PV+ cells (WT, n=65 cells; Kcnc1 -A421V, n=60 cells).", "stats": [ "n=847", "N=4", "n=901", "N=3", "n=65", "n=60" ], "panels": [ "fig8s1a", "fig8s1b" ] }, { "uid": "results-227", "section": "results", "text": "( E\u2013F ) Mean transient height in ( E ) PV\u2013 and ( F ) PV+ cells.", "stats": [], "panels": [ "fig8s1e", "fig8s1f" ] }, { "uid": "results-231", "section": "results", "text": "( G\u2013H ) Boxplot of percent of active ( G ) PV\u2013 and ( H ) PV+ cells for each mouse.", "stats": [], "panels": [ "fig8s1g", "fig8s1h" ] }, { "uid": "results-236", "section": "results", "text": "Of note, this held true even if only cells that displayed at least one transient throughout the recording were included in the analysis ( Figure 8\u2014figure supplement 1A and B ).", "stats": [], "panels": [ "fig8s1" ] }, { "uid": "results-240", "section": "results", "text": "These decreases in the frequency of PV\u2013 cell transients and the height of PV+ cell transients were not seen during epochs where the mouse was running ( Figure 8\u2014figure supplement 1C\u2013F ).", "stats": [], "panels": [ "fig8s1" ] }, { "uid": "results-241", "section": "results", "text": "We also observed no differences in the overall percentage of cells that were active in Kcnc1 -A421V/+ relative to WT mice ( Figure 8\u2014figure supplement 1G and H ).", "stats": [], "panels": [ "fig8s1" ] }, { "uid": "results-255", "section": "results", "text": "Recordings in wild-type (WT) (N = 4) control mice did not show epileptic seizures or runs of spikes.", "stats": [ "N = 4" ], "panels": [] }, { "uid": "captions-008", "section": "captions", "text": "[panels detected: a, b, c, d, e] === Figure 1s1 === Figure 1\u2014figure supplement 1. Pvalb-tdTomato reporter effectively labels parvalbumin-positive fast-spiking GABAergic inhibitory interneurons (PV-INs) in wild-type (WT) and Kcnc1 -A421V/+ mice.", "stats": [], "panels": [ "fig1s1" ] }, { "uid": "captions-013", "section": "captions", "text": "( B ) Counts of PV cells per unit area (mm 2 ) are not different between WT and Kcnc1 -A421V/+ mice (N=3 mice/genotype).", "stats": [ "N=3" ], "panels": [] }, { "uid": "captions-020", "section": "captions", "text": "Onset of developmental and motor benchmarks for WT (N=7) and Kcnc1 -A421V/+ (N=10) mice.", "stats": [ "N=7", "N=10" ], "panels": [] }, { "uid": "captions-025", "section": "captions", "text": "( B ) Average escape latency during the acquisition phase for WT (black; N=15) and Kcnc1 -A421V/+ (green; N=13) mice.", "stats": [ "N=15", "N=13" ], "panels": [] }, { "uid": "captions-027", "section": "captions", "text": "(D\u2013F) Group data for WT (black; N=16) and Kcnc1 -A421V/+ mice (green; N=15) during the Y-maze test for spatial working memory.", "stats": [ "N=16", "N=15" ], "panels": [] }, { "uid": "captions-035", "section": "captions", "text": "( D ) Average voltage-gated K + channel current density for WT (n=13 macropatches, N=3 mice) and Kcnc1 -A421V/+ (n=17, N=3 mice).", "stats": [ "n=13", "N=3", "n=17", "N=3" ], "panels": [] }, { "uid": "captions-054", "section": "captions", "text": "( D ) Average relationship between PV-IN AP frequency in response to a range of current injections for juvenile WT (n=20 cells, N = 9 mice) and Kcnc1 -A421V/+ (n=36 cells, N = 12 mice).", "stats": [ "n=20", "N = 9", "n=36", "N = 12" ], "panels": [] }, { "uid": "captions-063", "section": "captions", "text": "[panels detected: a, b, c, d, e, f, g, h, i, j] === Figure 4s1 === Figure 4\u2014figure supplement 1. Intrinsic physiology of neocortical layer II-IV parvalbumin-positive fast-spiking GABAergic inhibitory interneurons (PV-INs) remains impaired when resting membrane potential is not normalized.", "stats": [], "panels": [ "fig4s1" ] }, { "uid": "captions-076", "section": "captions", "text": "( C ) Average frequency-current relationship for WT (n=20 cells, N = 9 mice) and Kcnc1 -A421V/+ (n=32 cells, N = 12 mice) PV-INs with uncorrected resting membrane potential.", "stats": [ "n=20", "N = 9", "n=32", "N = 12" ], "panels": [] }, { "uid": "captions-081", "section": "captions", "text": "( D ) Average voltage-gated K + channel current density for WT (n=8 macropatches, N=3 mice) and Kcnc1 -A421V/+ (n=10, N=3 mice) relative to membrane potential.", "stats": [ "n=8", "N=3", "n=10", "N=3" ], "panels": [] }, { "uid": "captions-087", "section": "captions", "text": "( K ) Average relationship between excitatory cell AP frequency in response to a range of current injections for WT (N=23 cells, N=3 mice) and Kcnc1 -A421V/+ (n=22, N=3 mice).", "stats": [ "N=23", "N=3", "n=22", "N=3" ], "panels": [] }, { "uid": "captions-092", "section": "captions", "text": "( D ) Average frequency-current relationship for WT (black; n=12, N=4) and Kcnc1 -A421V/+ (n=12, N=4) mice.", "stats": [ "n=12", "N=4", "n=12", "N=4" ], "panels": [] }, { "uid": "captions-107", "section": "captions", "text": "[panels detected: a, b, c, d, e, f, g, h, i, j, k, l] === Figure 6s1 === Figure 6\u2014figure supplement 1. Excitatory neuron to parvalbumin-positive fast-spiking GABAergic inhibitory interneuron (PV-IN) unitary excitatory synaptic neurotransmission is unaltered in juvenile (postnatal day [P]16\u201321) Kcnc1 -A421V/+ mice.", "stats": [], "panels": [ "fig6s1" ] }, { "uid": "captions-121", "section": "captions", "text": "( D ) Connection probability between WT (14 of 36, N=8 mice) and Kcnc1 -A421V/+ (13 of 36, N=8 mice) pairs PV-INs and nearby excitatory cells.", "stats": [ "N=8", "N=8" ], "panels": [] }, { "uid": "captions-139", "section": "captions", "text": "[panels detected: a, b, c, d, e, f, g, h, i, j] === Figure 8s1 === Figure 8\u2014figure supplement 1. Analysis of in vivo two-photon calcium imaging data.", "stats": [], "panels": [ "fig8s1" ] }, { "uid": "captions-140", "section": "captions", "text": "( A ) PV\u2013 (wild-type [WT], n=847 cells, N=4 mice; Kcnc1 -A421V, n=901 cells, N=3 mice) and ( B ) PV+ cells (WT, n=65 cells; Kcnc1 -A421V, n=60 cells).", "stats": [ "n=847", "N=4", "n=901", "N=3", "n=65", "n=60" ], "panels": [] }, { "uid": "captions-151", "section": "captions", "text": "( C ) Raster plot indicating nonfatal seizures (blue bars), seizure-induced sudden death (red bars), interictal runs of spikes (green bars) without clear behavior manifestation, and periods of repetitive myoclonic seizures (yellow shading) for each mouse examined (N=12).", "stats": [ "N=12" ], "panels": [] }, { "uid": "captions-152", "section": "captions", "text": "Recordings in wild-type (WT) (N = 4) control mice did not show epileptic seizures or runs of spikes.", "stats": [ "N = 4" ], "panels": [] } ] } }