Biology subjects

Goldberg, E. M.

Publications and source records attributed to Goldberg, E. M..

14 recordsLinked to original sources

bioRxiv2026

Epilepsy and premature mortality driven by inhibitory neuron dysfunction in a mouse model of SCN1A gain-of-function neurodevelopmental disorder

The gene most commonly implicated in epilepsy, SCN1A, encodes the neuronal voltage-gated sodium channel subunit NaV1.1. SCN1A variants that reduce sodium current ("loss of function" variants) cause Dravet syndrome, a neurodevelopmental disorder defined by treatment-resistant temperature-sensitive epilepsy with onset at/around 5 months of age, developmental delay/intellectual disability, and features of or formal diagnosis autism. However, an emerging group of variants cause "gain of function" (GoF) effects on NaV1.1 and result in a distinct presentation with earlier onset than Dravet syndrome and prominent movement disorder but without temperature sensitivity. We developed the first mouse model of SCN1A GoF epilepsy with heterozygous Cre-dependent expression of the recurrent patient variant Scn1a-p.R1636Q. Global expression of this variant causes premature mortality in 100% (64/64) of mutant mice between postnatal day 12-18 due to spontaneous, convulsive seizures. Activation of the mutant allele in parvalbumin interneurons (Dlx5/6-Cre or PV-Cre), but not excitatory neurons (Slc17a7-Cre) or other interneuron subtypes (VIP-Cre or Sst-Cre), recapitulates the premature mortality and epilepsy phenotypes. Treatment of Scn1a-p.R1636Q mutant mice with the sodium channel blocker GS967 markedly prolongs lifespan. This work is the first study of SCN1A GoF epilepsy in a preclinical model in vivo. Further investigation in the Scn1aflox(R1636Q)mouse will yield new mechanistic insights into disease mechanisms to drive advances in the treatment of SCN1A GoF epilepsy.

neuroscience↗

bioRxiv2026

Use-dependent regulation of the axonal action potential in parvalbumin-expressing interneurons

The action potential (AP) is thought to be generated at the axon initial segment and to faithfully propagate along the axon. However, data from both invertebrate and mammalian systems show that the axon is an underappreciated locus of activity modulation and neuronal computation. We assessed axonal AP propagation in neocortical parvalbumin-expressing interneurons (PVINs) during prolonged, high-frequency activity through paired whole-cell somatic and axon-attached patch clamp recordings in acute brain slices from mouse and human. We found that PV-IN axonal AP propagation remains robust during prolonged activity at moderate frequencies, such as during the entrainment to PV-IN firing patterns recorded in awake, behaving mice in vivo. However, prolonged, high-frequency activity during evoked trains of APs and during seizure-like events resulted in changes in the waveform of the axonal (but not somatic) AP, at least in part due to intrinsic use-dependent mechanisms. This use-dependent decrement in the axonal AP waveform is associated with decreases in calcium influx at PV-IN boutons and subsequent PV-IN-mediated synaptic transmission, indicating this phenomenon may lead to a dissociation between somatic and axonal excitability that could shape PV-IN contributions to circuit dynamics during periods of high activity.

neuroscience↗

bioRxiv2026

Developmental dysregulation of chandelier cell excitability in a mouse model of Dravet Syndrome

Chandelier cells (ChCs) are a rare and highly specialized sub-type of inhibitory neuron in the cerebral cortex that specifically and exclusively form synapses onto the axon initial segment of excitatory neurons and thereby exert powerful control of excitability. We applied a newly developed, cell type-specific enhancer element to label ChCs and assess their electrophysiological and morphological properties across development in Dravet Syndrome (Scn1a+/- mice), a prominent neurodevelopmental disorder defined by epilepsy and features of autism spectrum disorder. Dravet Syndrome is known to predominantly impact GABAergic interneurons. We found that ChCs from juvenile Scn1a+/- mice (postnatal day, P18-21) exhibit impaired excitability, and that deficits largely persist in young adulthood (P35-56). These findings are distinct from prior observations in the more common subtype of parvalbumin-positive interneurons, basket cells. We found no differences in the axonal or dendritic morphology of ChCs at either time point. Our results suggest a role for ChCs in the pathogenesis of Dravet Syndrome and constitute the first targeted study of ChC function in a specific genetically-defined neurodevelopmental disorder.

neuroscience↗

bioRxiv2024

Attenuated ectopic action potential firing in parvalbumin expressing interneurons in a mouse model of Dravet Syndrome

Dravet syndrome is caused by heterozygous loss-of-function variants in SCN1A, which encodes the voltage-gated sodium channel Nav1.1. Our recent work suggests that a primary pathogenic mechanism of Dravet syndrome is impaired action potential propagation along axons of cortical parvalbumin-positive fast-spiking GABAergic interneurons (PVINs). Ectopic action potentials (EAPs) are action potentials that initiate distal to the axon initial segment. We recently demonstrated that a large proportion of PVINs fire EAPs during periods of increased excitation. Although their function remains unknown, EAPs may play a role in amplifying (when occurring in excitatory cells) and/or preventing seizures (when occurring in interneurons). Regardless of function, their generation in distal axons suggests that EAP frequency could be a useful proxy for distal axonal excitability. We hypothesized that EAPs are attenuated in PVINs from Dravet syndrome (Scn1a+/-) mice due to dysfunction of the distal axon. We induced EAPs in PVINs in acute brain slices prepared from male and female wildtype (WT) and Scn1a+/- mice at P18-21 and P35-56, when we have previously identified axonal conduction deficits in Scn1a+/- PVINs. We elicited EAPs in 17/22 (77%) of WT PVINs, including 6 (22%) that exhibited barrages of EAPs. In contrast, Scn1a+/- PVINs never fired barrages (0%), and only 8/23 (34%) exhibited even single EAPs. This finding adds to the body of evidence supporting impaired action potential propagation in Dravet syndrome PVINs, and is the first evidence of impaired EAP firing in a disease model, suggesting that dysregulation of EAPs could be involved in the pathophysiology of human disease.

neuroscience↗

bioRxiv2024

Impaired excitability of fast-spiking neurons in a novel mouse model of KCNC1 epileptic encephalopathy

The recurrent pathogenic variant KCNC1-p.Ala421Val (A421V) is a cause of developmental and epileptic encephalopathy characterized by moderate-to-severe developmental delay/intellectual disability, and infantile-onset treatment-resistant epilepsy with multiple seizure types including myoclonic seizures. Yet, the mechanistic basis of this disease, and of the KCNC1 disease spectrum, is unclear. KCNC1 encodes Kv3.1, a voltage-gated potassium channel subunit that is highly and selectively expressed in neurons capable of generating action potentials at high frequency, including parvalbumin-positive fast-spiking GABAergic inhibitory interneurons in cerebral cortex (PV-INs) known to be important for cognitive function and plasticity as well as control of network excitation to prevent seizures. In this study, we generate a novel transgenic mouse model with conditional expression of the Ala421Val pathogenic missense variant (Kcnc1-A421V/+ mice) to explore the specific physiological mechanisms of KCNC1 developmental and epileptic encephalopathy. Our results indicate that global heterozygous expression of the A421V variant leads to cognitive impairment, epilepsy, and premature lethality. We observe decreased PV-IN cell surface expression of Kv3.1 via immunohistochemistry, decreased voltage-gated potassium current density in PV-INs using outside-out nucleated macropatch recordings in brain slice, and profound impairments in the intrinsic excitability of cerebral cortex PV-INs (but not excitatory neurons) in current-clamp electrophysiology. In vivo two-photon calcium imaging revealed altered basal activity in Kcnc1-A421V/+ PV-INs and excitatory cells, as well as hypersynchronous discharges correlated with brief paroxysmal movements that were subsequently shown to be myoclonic seizures on electroencephalography. We found alterations in PV-IN-mediated inhibitory neurotransmission in young adult but not juvenile Kcnc1-A421V/+ mice relative to wild-type controls. Together, these results establish the specific impact of the recurrent Kv3.1-A421V variant on neuronal excitability and synaptic physiology across development to drive network dysfunction underlying KCNC1 epileptic encephalopathy.

neuroscience↗

bioRxiv2024

Optimizing clinical interpretability of functional evidence in epilepsy-related ion channel variants

Variants in genes encoding the voltage-gated ion channels are among the most common monogenic causes of epilepsy and neurodevelopmental disorders. Functional effects of a variant are increasingly important for diagnosis and therapeutic decisions. To incorporate knowledge regarding functional consequences in formal clinical variant interpretation, we developed an approach for evaluating multiple functional measurements within the Bayesian framework of the modified ACMG/AMP guidelines. We analyzed 216 functional assessments of 191 variants in SCN1A (n=74), SCN2A (n=66), SCN3A (n=18), and SCN8A (n=33). Of 20 commonly measured biophysical parameters, the most frequent drivers of overall functional consequence were persistent current (f=0.54), voltage dependence of activation (f=0.51), and voltage dependence of fast inactivation (f=0.40) for gain-of-function and peak current (f=0.87) for loss-of-function. By comparing measurements of 23 benign variants, we determined thresholds by which published data on these four parameters confer Strong evidence of variant pathogenicity (likelihood ratio > 18.7) under the ACMG/AMP rubric. Similarly, we delineated evidence weights for the most common epilepsy-related potassium channel gene, KCNQ2, through reports of 80 pathogenic and 24 benign variants, accounting for heterozygous and homozygous experimental conditions. We collected the resulting categorization of functional data into FENICS, a biomedical ontology of 152 standardized terms for coherent annotation of electrophysiological results. Across 271 variants in SCN1A/2A/3A/8A and KCNQ2, 1,731 annotations are available in ClinVar, facilitating use of this evidence in variant classification. In summary, we introduce and apply an ACMG/AMP-calibrated framework for electrophysiological studies in epilepsy-related channelopathies to delineate the impact of functional evidence on clinical variant interpretation.

genetics↗

bioRxiv2023

High density SNP array and reanalysis of genome sequencing uncovers CNVs associated with neurodevelopmental disorders in KOLF2.1J iPSCs

The KOLF2.1J iPSC line was recently proposed as a reference iPSC to promote the standardization of research studies in the stem cell field. Due to overall good performance differentiating to neural cell lineages, high gene editing efficiency, and absence of genetic variants associated to neurological disorders KOLF2.1J iPSC line was particularly recommended for neurodegenerative disease modeling. However, our work uncovers that KOLF2.1J hPSCs carry heterozygous small copy number variants (CNVs) that cause DTNBP1, JARID2 and ASTN2 haploinsufficiencies, all of which are associated with neurological disorders. We further determine that these CNVs arose in vitro over the course of KOLF2.1J iPSC generation from a healthy donor-derived KOLF2 iPSC line and affect the expression of DNTBP1, JARID2 and ASTN2 proteins in KOLF2.1J iPSCs and neural progenitors. Therefore, our study suggests that KOLF2.1J iPSCs carry genetic variants that may be deleterious for neural cell lineages. This data is essential for a careful interpretation of neural cell studies derived from KOLF2.1J iPSCs and highlights the need for a catalogue of iPSC lines that includes a comprehensive genome characterization analysis.

genetics↗

bioRxiv2022

The SCN1A Philadelphia variant - a gain-of-function mutation causing an early-onset epileptic encephalopathy

ObjectiveLoss-of-function variants in SCN1A cause Dravet Syndrome, the most common genetic developmental and epileptic encephalopathy (DEE). However, emerging evidence suggests separate entities of SCN1A-related disorders due to gain-of-function variants. Here, we aim to refine the clinical, genetic, and functional electrophysiological features of a recurrent p.R1636Q gain-of-function variant, identified in four individuals at a single center. MethodsIndividuals carrying the recurrent SCN1A p.R1636Q variant were identified through diagnostic testing. Whole-cell voltage-clamp electrophysiological recording in HEK-293T cells was performed to compare the properties of sodium channels containing wild-type Nav1.1 or Nav1.1-R1636Q along with both Nav{beta}1 and Nav{beta}2 subunits, including response to oxcarbazepine. To delineate differences to other SCN1A-related epilepsies, we analyzed electronic medical records. ResultsAll four individuals had an early-onset DEE characterized by focal tonic seizures and additional seizure types starting in the first few weeks of life. Electrophysiological analysis showed a mixed gain-of-function effect with normal current density, a leftward (hyperpolarized) shift of steady-state inactivation, and slower inactivation kinetics leading to a prominent late sodium current (INa). The observed functional changes closely paralleled effects of pathogenic variants in SCN3A and SCN8A at corresponding positions. Both wildtype and variant exhibited sensitivity to block by oxcarbazepine, partially correcting electrophysiological abnormalities of the SCN1A p.R1636Q variant. Clinically, a single individual responded to treatment with oxcarbazepine. Across 51 individuals with SCN1A-related epilepsies, those with the recurrent p.R1636Q variants had the earliest ages of onset. InterpretationThe recurrent SCN1A p.R1636Q variant causes a clinical entity with a wider clinical spectrum than previously reported, characterized by ultra early-onset epilepsy and absence of prominent movement disorder. Functional consequences of this variant lead to mixed loss- and gain-of-function that is partially corrected by oxcarbazepine. The recurrent p.R1636Q variant represents one of the most common causes of early-onset SCN1A-related epilepsies with separate treatment and prognosis implications. Key PointsO_LILoss-of-function variants in SCN1A cause Dravet syndrome, but gain-of-function variants have an emerging clinical spectrum. C_LIO_LIThe SCN1A p.R1636Q variant shows similar overall gain-of-function effects to identical missense variants in other voltage-gated sodium channels. C_LIO_LIFeatures of four unreported individuals with SCN1A p.R1636Q from a single center expand the SCN1A gain-of-function phenotype. C_LIO_LIIndividuals with this variant are recognizable by their ultra early-onset seizures in contrast to Dravet syndrome. C_LI

genetics↗

bioRxiv2022

Exogenous Nav1.1 activity in excitatory and inhibitory neurons reverts Dravet syndrome comorbidities when delivered post-symptom onset in mice with Dravet

Dravet syndrome (DS), an intractable childhood epileptic encephalopathy with a high fatality rate, is caused by loss-of-function mutations in one allele of SCN1A, which encodes NaV1.1. In contrast to other epilepsies, pharmaceutical treatment for DS is limited. Here, we demonstrate that viral vector-mediated delivery of a codon-modified SCN1A cDNA improves DS comorbidities in juvenile and adolescent DS mice (Scn1aA1783V/WT). Notably, bilateral vector injections into the hippocampus or thalamus of DS mice improved the survival of the mice, reduced the occurrence of epileptic spikes, provided protection from thermally-induced seizures, and corrected background electrocorticography activity. Together, our results provide a proof-of-concept for the potential of SCN1A delivery as a therapeutic approach for infants and adolescents with DS-associated comorbidities.

neuroscience↗

bioRxiv2021

Developmentally-regulated impairment of parvalbumin interneuron synaptic transmission in an experimental model of Dravet syndrome

Dravet syndrome (DS) is a neurodevelopmental disorder defined by epilepsy, intellectual disability, and sudden death, due to heterozygous variants in SCN1A with loss of function of the sodium channel subunit Nav1.1. Nav1.1-expressing parvalbumin GABAergic interneurons (PV-INs) from pre-weanling Scn1a+/- mice show impaired action potential generation. A novel approach assessing PV-IN function in the same mice at two developmental time points showed that, at post-natal day (P) 16-21, spike generation was impaired all mice, deceased prior or surviving to P35. However, synaptic transmission was selectively dysfunctional in pre-weanling mice that did not survive. Spike generation in surviving mice normalized by P35, yet we again identified abnormalities in synaptic transmission. We conclude that combined dysfunction of PV-IN spike generation and synaptic transmission drives disease severity, while ongoing dysfunction of synaptic transmission contributes to chronic pathology. Modeling revealed that PV-IN axonal propagation is more sensitive to decreases in sodium conductance than spike generation.

neuroscience↗

bioRxiv2021

Corticohippocampal circuit dysfunction in a mouse model of Dravet syndrome

Dravet syndrome (DS) is a neurodevelopmental disorder defined by treatment-resistant epilepsy, autism spectrum disorder, and sudden death, due to pathogenic variants in SCN1A encoding the Nav1.1 sodium channel subunit. Convergent data suggest hippocampal dentate gyrus (DG) pathology. We found that optogenetic stimulation of entorhinal cortex was ictogenic in DS (Scn1a+/-) but not wild-type mice in vivo. Two-photon calcium imaging in brain slice demonstrated profound impairment in filtering of perforant path input by DG in young adult Scn1a+/- mice due to enhanced excitatory input to granule cells. Excitability of parvalbumin interneurons (PV-INs) was near-normal and selective activation of PV-INs rescued circuit impairments. This demonstrates developmental reorganization of hippocampal circuitry that can be modulated by recruitment of functional PV-INs, suggesting potential therapeutic approaches towards seizure modulation. The identified circuit abnormality mirrors that seen in models of chronic temporal lobe epilepsy, suggesting convergent mechanisms linking genetic and acquired causes of temporal lobe-onset seizures.

neuroscience↗

bioRxiv2019

Viral manipulation of functionally distinct neurons from mice to humans

Recent success in identifying gene regulatory elements in the context of recombinant adeno-associated virus vectors have enabled cell type-restricted gene expression. However, within the cerebral cortex these tools are presently limited to broad classes of neurons. To overcome this limitation, we developed a strategy that led to the identification of multiple novel enhancers to target functionally distinct neuronal subtypes. By investigating the regulatory landscape of the disease gene Scn1a, we identified enhancers that target the breadth of its expression, including two that are selective for parvalbumin and vasoactive intestinal peptide cortical interneurons. Demonstrating the functional utility of these elements, we found that the PV-specific enhancer allowed for the selective targeting and manipulation of these neurons across species, from mice to humans. Finally, we demonstrate that our selection method is generalizable to other genes and characterize four additional PV-specific enhancers with exquisite specificity for distinct regions of the brain. Altogether, these viral tools can be used for cell-type specific circuit manipulation and hold considerable promise for use in therapeutic interventions.

neuroscience↗

bioRxiv2019

Enhanced maturation of fast-spiking interneurons driven by mTOR activation

The use of stem cell derived neurons for cell-based therapies is limited by a protracted maturation. We present a novel approach for accelerating the post-mitotic maturation of human stem cell derived interneurons via the activation of mTOR signaling. Lox sites were placed within PTEN, a key mTOR inhibitor, in a cortical interneuron (CIn) reporter line. Following directed differentiation and purification by FACS, the CIns were exposed to Cre-expressing lentivirus, then transplanted into mouse neocortex or plated onto cultured rat neocortex. Input synaptogenesis and dendritogenesis was greatly enhanced in the PTEN-deleted CIns. Whole-cell recording of the PTEN-deleted CIns in slices of transplanted neocortex revealed multiple indices of enhanced maturation. Finally, we observed similar effects using transient, doxycycline-inducible activation of AKT. We thus present an inducible, reversible approach for accelerating the maturation of human stem cell derived CIns, and to study the influences of this disease-related signaling system in human neurons.

neuroscience↗

bioRxiv2019

High throughput Characterization of KCNB1 variants Associated with Developmental and Epileptic Encephalopathy

Pathogenic variants in KCNB1, encoding the voltage-gated potassium channel Kv2.1, are associated with developmental and epileptic encephalopathies (DEE). Previous functional studies on a limited number of KCNB1 variants indicated a range of molecular mechanisms by which variants affect channel function, including loss of voltage sensitivity, loss of ion selectivity, and reduced cell-surface expression. We evaluated a series of 17 KCNB1 variants associated with DEE or neurodevelopmental disorder (NDD) to rapidly ascertain channel dysfunction using high-throughput functional assays. Specifically, we investigated the biophysical properties and cell-surface expression of variant Kv2.1 channels expressed in heterologous cells using high-throughput automated electrophysiology and immunocytochemistry-flow cytometry. Pathogenic variants exhibited diverse functional defects, including altered current density and shifts in the voltage-dependence of activation and/or inactivation, as homotetramers or when co-expressed with wild-type Kv2.1. Quantification of protein expression also identified variants with reduced total Kv2.1 expression or deficient cell-surface expression.\n\nOur study establishes a platform for rapid screening of functional defects of KCNB1 variants associated with DEE and other NDDs, which will aid in establishing KCNB1 variant pathogenicity and may enable discovery of targeted strategies for therapeutic intervention based on molecular phenotype.

genetics↗