Similar Datasets
Project description:The spinal cord contains neural networks that enable regionally distinct motor outputs along the body axis. Nevertheless, it remains unclear how segment-specific motor computations are processed because the cardinal interneuron classes that control motor neurons appear uniform at each level of the spinal cord. V2a interneurons are essential to both forelimb and hindlimb movements, and here we identify two major types that emerge during development: type I neurons marked by high Chx10 form recurrent networks with neighboring spinal neurons and type II neurons that downregulate Chx10 and project to supraspinal structures. Types I and II V2a interneurons are arrayed in counter-gradients, and this network activates different patterns of motor output at cervical and lumbar levels. Single-cell RNA sequencing (RNA-seq) revealed type I and II V2a neurons are each comprised of multiple subtypes. Our findings uncover a molecular and anatomical organization of V2a interneurons reminiscent of the orderly way motor neurons are divided into columns and pools.
| S-EPMC8601153 | biostudies-literature
Project description:The spinal cord contains neural networks that enable regionally-distinct motor outputs along the body axis. Nevertheless, it remains unclear how segment-specific motor computations are processed because the cardinal interneuron classes that control motor neurons appear uniform at each level of the spinal cord. V2a interneurons are essential to both fore and hindlimb movements and here we identified two major types that emerge during development: Type-I neurons marked by high Chx10 form recurrent networks with neighboring spinal neurons, and Type-II that downregulate Chx10 and project to supraspinal structures. Type-I and -II V2a interneurons are arrayed in counter-gradients and this network activates different patterns of motor output at cervical and lumbar levels. Single cell RNA-seq revealed Type-I and -II V2a neurons are each comprised of multiple subtypes. Our findings uncover a molecular and anatomical organization of V2a interneurons reminiscent of the orderly way motor neurons are divided into columns and pools.
2018-02-22 | GSE108788 | GEO
Project description:The spinal cord contains neural networks that enable regionally-distinct motor outputs along the body axis. Nevertheless, it remains unclear how segment-specific motor computations are processed because the cardinal interneuron classes that control motor neurons appear uniform at each level of the spinal cord. V2a interneurons are essential to both fore and hindlimb movements and here we identified two major types that emerge during development: Type-I neurons marked by high Chx10 form recurrent networks with neighboring spinal neurons, and Type-II that downregulate Chx10 and project to supraspinal structures. Type-I and -II V2a interneurons are arrayed in counter-gradients and this network activates different patterns of motor output at cervical and lumbar levels. Single cell RNA-seq revealed Type-I and -II V2a neurons are each comprised of multiple subtypes. Our findings uncover a molecular and anatomical organization of V2a interneurons reminiscent of the orderly way motor neurons are divided into columns and pools.
2018-02-22 | GSE108775 | GEO
Project description:Graded arrays of spinal and supraspinal V2a interneuron subtypes underlie forelimb and hindlimb motor control
| PRJNA428536 | ENA
Project description:Graded arrays of spinal and supraspinal V2a interneuron subtypes underlie forelimb and hindlimb motor control [RNA-seq]
| PRJNA428528 | ENA
Project description:Graded arrays of spinal and supraspinal V2a interneuron subtypes underlie forelimb and hindlimb motor control [scRNA-seq]
| PRJNA428534 | ENA
Project description:Sensitive and objective biomarkers of neuronal injury, degeneration, and regeneration can help facilitate translation of experimental findings into clinical testing. Whereas measures of upper motor neuron connectivity have been readily established, functional assessments of lower motor neuron (LMN) innervation of forelimb muscles are lacking. Compound muscle action potential (CMAP) and motor unit (MU) number estimation (MUNE) are well-established methods that allow longitudinal MU integrity monitoring in patients. In analogy we refined CMAP and MUNE methods for assessing spinal MU input in the rat forelimb and hindlimb. Repeated CMAP and MUNE recordings are robust (coefficients of variability: 4.5-11.3%), and MUNE measurements from forelimb wrist flexor muscles (415?±?8 [SEM]) align with back-traced anatomical LMN counts (336?±?16 [SEM]). For disease validation, cross-sectional blinded electrophysiological and muscle contractility measurements were obtained in a cohort of G93A SOD1 mutant overexpressing rats and compared with controls. Longitudinal assessment of mutant animals demonstrated progressive motor unit decline in the hindlimb to a greater extent than the forelimb. Hindlimb CMAP and MUNE demonstrated strong correlations with plantarflexion muscle contractility. Cross-species assessment of upper/fore- limb and lower/hind- limb motor units using objective electrophysiological CMAP and MUNE values as biomarkers will guide and improve bi-directional translation.
| S-EPMC6853930 | biostudies-literature
Project description:LIM transcription factors bind to nuclear LIM interactor (Ldb/NLI/Clim) in specific ratios to form higher-order complexes that regulate gene expression. Here we examined how the dosage of LIM homeodomain proteins Isl1 and Isl2 and LIM-only protein Lmo4 influences the assembly and function of complexes involved in the generation of spinal motor neurons (MNs) and V2a interneurons (INs). Reducing the levels of Islet proteins using a graded series of mutations favored V2a IN differentiation at the expense of MN formation. Although LIM-only proteins (LMOs) are predicted to antagonize the function of Islet proteins, we found that the presence or absence of Lmo4 had little influence on MN or V2a IN specification. We did find, however, that the loss of MNs resulting from reduced Islet levels was rescued by eliminating Lmo4, unmasking a functional interaction between these proteins. Our findings demonstrate that MN and V2a IN fates are specified by distinct complexes that are sensitive to the relative stoichiometries of the constituent factors and we present a model to explain how LIM domain proteins modulate these complexes and, thereby, this binary-cell-fate decision.
| S-EPMC2723064 | biostudies-literature
Project description:V2a interneurons are located in the hindbrain and spinal cord, where they provide rhythmic input to major motor control centers. Many of the phenotypic properties and functions of excitatory V2a interneurons have yet to be fully defined. Definition of these properties could lead to novel regenerative therapies for traumatic injuries and drug targets for chronic degenerative diseases. Here we describe how to produce V2a interneurons from mouse and human pluripotent stem cells (PSCs), as well as strategies to characterize and mature the cells for further analysis. The described protocols are based on a sequence of small-molecule treatments that induce differentiation of PSCs into V2a interneurons. We also include a detailed description of how to phenotypically characterize, mature, and freeze the cells. The mouse and human protocols are similar in regard to the sequence of small molecules used but differ slightly in the concentrations and durations necessary for induction. With the protocols described, scientists can expect to obtain V2a interneurons with purities of ~75% (mouse) in 7 d and ~50% (human) in 20 d.
| S-EPMC7243683 | biostudies-literature
Project description:During development, two cell types born from closely related progenitor pools often express identical transcriptional regulators despite their completely distinct characteristics. This phenomenon implies the need for a mechanism that operates to segregate the identities of the two cell types throughout differentiation after initial fate commitment. To understand this mechanism, we investigated the fate specification of spinal V2a interneurons, which share important developmental genes with motor neurons (MNs). We demonstrate that the paired homeodomain factor Chx10 functions as a critical determinant for V2a fate and is required to consolidate V2a identity in postmitotic neurons. Chx10 actively promotes V2a fate, downstream of the LIM-homeodomain factor Lhx3, while concomitantly suppressing the MN developmental program by preventing the MN-specific transcription complex from binding and activating MN genes. This dual activity enables Chx10 to effectively separate the V2a and MN pathways. Our study uncovers a widely applicable gene regulatory principle for segregating related cell fates.
| S-EPMC8109239 | biostudies-literature