The development of efficient and targeted methods for delivering DNA in vivo has long been a major focus of research. In this study, we introduce a gene Delivery approach Admitted by small Metabolites, named gDAM, for the efficient and targeted delivery of naked DNA into astrocytes in the adult brains of mice. gDAM utilizes a straightforward combination of DNA and small metabolites, including glycine, L-proline, L-serine, L-histidine, D-alanine, Gly-Gly, and Gly-Gly-Gly, to achieve astrocyte-specific delivery of naked DNA, resulting in transient and robust gene expression in these cells.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
July 2024
Bicelles are discoidal lipid nanoparticles (LNPs) in which the planar bilayer and curved rim are, respectively, composed of long- and short-chain lipids. Bicellar LNPs have a hydrophobic core, allowing hydrophobic molecules and large molecular complexes such as quantum dots (QDs) to be encapsulated. In this study, CdSe/ZnS QDs were encapsulated in bicelles made of dipalmitoyl phosphatidylcholine, dihexanoyl phosphatidylcholine, dipalmitoyl phosphatidylglycerol, and distearoyl phosphatidylethanolamine conjugated with polyethylene glycerol amine 2000 to form a well-defined bicelle-QD nanocomplex (known as NANO-QD or bicelle-QD).
View Article and Find Full Text PDFSomatic mutations have emerged as the likely cause of focal epilepsies associated with developmental malformations and epilepsy-associated glioneuronal tumors (GNT). Somatic BRAFV600E mutations in particular have been detected in the majority of low-grade neuroepithelial tumors (LNETS) and in neurons in focal cortical dysplasias adjacent to epilepsy-associated tumors. Furthermore, conditional expression of an activating BRAF mutation in neocortex causes seizures in mice.
View Article and Find Full Text PDFDravet syndrome (DS) is a form of epilepsy with a high incidence of sudden unexpected death in epilepsy (SUDEP). Respiratory failure is a leading cause of SUDEP, and DS patients' frequently exhibit disordered breathing. Despite this, mechanisms underlying respiratory dysfunction in DS are unknown.
View Article and Find Full Text PDFCellular changes underlying malformations of human cortical development may be difficult to identify with traditional mouse models. Two recent Cell Stem Cell papers, Li et al. (2017) and Bershteyn et al.
View Article and Find Full Text PDFCollybistin (CB) is a guanine nucleotide exchange factor selectively localized to γ-aminobutyric acid (GABA)ergic and glycinergic postsynapses. Active CB interacts with gephyrin, inducing the submembranous clustering and the postsynaptic accumulation of gephyrin, which is a scaffold protein that recruits GABA receptors (GABA Rs) at the postsynapse. CB is expressed with or without a src homology 3 (SH3) domain.
View Article and Find Full Text PDFUnlabelled: Dyslexia is the most common developmental language disorder and is marked by deficits in reading and phonological awareness. One theory of dyslexia suggests that the phonological awareness deficit is due to abnormal auditory processing of speech sounds. Variants in DCDC2 and several other neural migration genes are associated with dyslexia and may contribute to auditory processing deficits.
View Article and Find Full Text PDFCurr Protoc Pharmacol
March 2016
Many animal models have been developed to investigate the sources of central nervous system (CNS) tumor heterogeneity. Reviewed in this unit is a recently developed CNS tumor model using the piggyBac transposon system delivered by in utero electroporation, in which sources of tumor heterogeneity can be conveniently studied. Their applications for studying CNS tumors and drug discovery are also reviewed.
View Article and Find Full Text PDFVariants in DCDC2 have been associated with reading disability in humans, and targeted mutation of Dcdc2 in mice causes impairments in both learning and sensory processing. In this study, we sought to determine whether Dcdc2 mutation affects functional synaptic circuitry in neocortex. We found mutation in Dcdc2 resulted in elevated spontaneous and evoked glutamate release from neurons in somatosensory cortex.
View Article and Find Full Text PDFDyslexia is a learning disability characterized by difficulty learning to read and write. The underlying biological and genetic etiology remains poorly understood. One candidate gene, dyslexia susceptibility 1 candidate 1 (DYX1C1), has been shown to be associated with deficits in short-term memory in dyslexic populations.
View Article and Find Full Text PDFUnderstanding single-neuron computations and encoding performed by spike-generation mechanisms of cortical neurons is one of the central challenges for cell electrophysiology and computational neuroscience. An established paradigm to study spike encoding in controlled conditions in vitro uses intracellular injection of a mixture of signals with fluctuating currents that mimic in vivo-like background activity. However this technique has two serious limitations: it uses current injection, while synaptic activation leads to changes of conductance, and current injection is technically most feasible in the soma, while the vast majority of synaptic inputs are located on the dendrites.
View Article and Find Full Text PDFJ Comp Neurol
June 2015
We studied the effect of clonal overexpression of neuroligin 3 (NL3) or neuroligin 2 (NL2) in the adult rat cerebral cortex following in utero electroporation (IUEP) at embryonic stage E14. Overexpression of NL3 leads to a large increase in vesicular gamma-aminobutyric acid (GABA) transporter (vGAT) and glutamic acid decarboxylase (GAD)65 in the GABAergic contacts that the overexpressing neurons receive. Overexpression of NL2 produced a similar effect but to a lesser extent.
View Article and Find Full Text PDFNephronophthisis-related ciliopathies (NPHP-RC) are recessive diseases characterized by renal dysplasia or degeneration. We here identify mutations of DCDC2 as causing a renal-hepatic ciliopathy. DCDC2 localizes to the ciliary axoneme and to mitotic spindle fibers in a cell-cycle-dependent manner.
View Article and Find Full Text PDFArcLight, a genetically encoded fluorescent protein voltage probe with a large ΔF/ΔV, is a fusion between the voltage sensing domain of the Ciona instestinalis voltage sensitive phosphatase and super ecliptic pHluorin carrying a single mutation (A227D in the fluorescent protein). Without this mutation the probe produces only a very small change in fluorescence in response to voltage deflections (∼ 1%). The large signal afforded by this mutation allows optical detection of action potentials and sub-threshold electrical events in single-trials in vitro and in vivo.
View Article and Find Full Text PDFLineage progression and diversification is regulated by the coordinated action of unique sets of transcription factors. Oligodendrocytes (OL) and astrocytes (AS) comprise the glial sub-lineages in the CNS, and the manner in which their associated regulatory factors orchestrate lineage diversification during development and disease remains an open question. Sox10 and NFIA are key transcriptional regulators of gliogenesis associated with OL and AS.
View Article and Find Full Text PDFCold Spring Harb Protoc
July 2014
In utero electroporation (IUE) is an effective transfection method for delivering plasmid DNA into neural progenitor cells and neurons of mammalian neocortex in vivo. Although IUE is effective at delivering multiple DNA plasmids into populations of cells, unfortunately plasmids delivered into neural progenitor cells remain largely episomal and often get inactivated or lost after cell division. This results in a form of "birthdate" labeling in which only the cell types that do not undergo a second cell division continue to express the transfected plasmids.
View Article and Find Full Text PDFIn utero RNAi of the dyslexia-associated gene Kiaa0319 in rats (KIA-) degrades cortical responses to speech sounds and increases trial-by-trial variability in onset latency. We tested the hypothesis that KIA- rats would be impaired at speech sound discrimination. KIA- rats needed twice as much training in quiet conditions to perform at control levels and remained impaired at several speech tasks.
View Article and Find Full Text PDFIn this unit we describe an overlay brain slice culture assay for studying migration of transgenic neurospheres derived from human embryonic stem cells (hESC). Neuronal progenitor cells were generated from hESC by derivation of embryoid bodies and rosettes. Rosettes were transfected using the PiggyBac transposon system with either control plasmids (GFP) or plasmid encoding a gene important for migration of neuronal progenitor cells, Doublecortin (DCX).
View Article and Find Full Text PDFKCNQ2 and KCNQ3 potassium channels have emerged as central regulators of pyramidal neuron excitability and spiking behavior. However, despite an abundance of evidence demonstrating that KCNQ2/3 heteromers underlie critical potassium conductances, it is unknown whether KCNQ2, KCNQ3, or both are obligatory for maintaining normal pyramidal neuron excitability. Here, we demonstrate that conditional deletion of Kcnq2 from cerebral cortical pyramidal neurons in mice results in abnormal electrocorticogram activity and early death, whereas similar deletion of Kcnq3 does not.
View Article and Find Full Text PDFUnlabelled: The etiology of central nervous system (CNS) tumor heterogeneity is unclear. To clarify this issue, a novel animal model was developed of glioma and atypical teratoid/rhabdoid-like tumor (ATRT) produced in rats by nonviral cellular transgenesis initiated in utero. This model system affords the opportunity for directed oncogene expression, clonal labeling, and addition of tumor-modifying transgenes.
View Article and Find Full Text PDFBackground: Variants in dyslexia-associated genes, including DCDC2, have been linked to altered neocortical activation, suggesting that dyslexia associated genes might play as yet unspecified roles in neuronal physiology.
Methods: Whole-cell patch clamp recordings were used to compare the electrophysiological properties of regular spiking pyramidal neurons of neocortex in Dcdc2 knockout (KO) and wild-type mice. Ribonucleic acid sequencing and reverse transcriptase polymerase chain reaction were performed to identify and characterize changes in gene expression in Dcdc2 KOs.
DYX1C1 has been associated with dyslexia and neuronal migration in the developing neocortex. Unexpectedly, we found that deleting exons 2-4 of Dyx1c1 in mice caused a phenotype resembling primary ciliary dyskinesia (PCD), a disorder characterized by chronic airway disease, laterality defects and male infertility. This phenotype was confirmed independently in mice with a Dyx1c1 c.
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