Characterization of a novel binding partner of the melanocortin-4 receptor: attractin-like protein.

PubMed Central

Haqq, Andrea M; René, Patricia; Kishi, Toshiro; Khong, Kathy; Lee, Charlotte E; Liu, Hongyan; Friedman, Jeffrey M; Elmquist, Joel K; Cone, Roger D

2003-01-01

The gene dosage effect of the MC4-R (melanocortin 4 receptor) on obesity suggests that regulation of MC4-R expression and function is critically important to the central control of energy homoeostasis. In order to identify putative MC4-R regulatory proteins, we performed a yeast two-hybrid screen of a mouse brain cDNA library using the mouse MC4-R intracellular tail (residues 303-332) as bait. We report here on one positive clone that shares 63% amino acid identity with the C-terminal part of the mouse attractin gene product, a single-transmembrane-domain protein characterized as being required for agouti signalling through the melanocortin 1 receptor. We confirmed a direct interaction between this ALP (attractin-like protein) and the C-terminus of the mouse MC4-R by glutathione S-transferase pulldown experiments, and mapped the regions involved in this interaction using N- and C-terminal truncation constructs; residues 303-313 in MC4-R and residues 1280-1317 in ALP are required for binding. ALP is highly expressed in brain, but also in heart, lung, kidney and liver. Furthermore, co-localization analyses in mice showed co-expression of ALP in cells expressing MC4-R in a number of regions known to be important in the regulation of energy homoeostasis by melanocortins, such as the paraventricular nucleus of hypothalamus and the dorsal motor nucleus of the vagus. PMID:14531729

Sequential photo-bleaching to delineate single Schwann cells at the neuromuscular junction.

PubMed

Brill, Monika S; Marinković, Petar; Misgeld, Thomas

2013-01-11

Sequential photo-bleaching provides a non-invasive way to label individual SCs at the NMJ. The NMJ is the largest synapse of the mammalian nervous system and has served as guiding model to study synaptic structure and function. In mouse NMJs motor axon terminals form pretzel-like contact sites with muscle fibers. The motor axon and its terminal are sheathed by SCs. Over the past decades, several transgenic mice have been generated to visualize motor neurons and SCs, for example Thy1-XFP and Plp-GFP mice, respectively. Along motor axons, myelinating axonal SCs are arranged in non-overlapping internodes, separated by nodes of Ranvier, to enable saltatory action potential propagation. In contrast, terminal SCs at the synapse are specialized glial cells, which monitor and promote neurotransmission, digest debris and guide regenerating axons. NMJs are tightly covered by up to half a dozen non-myelinating terminal SCs - these, however, cannot be individually resolved by light microscopy, as they are in direct membrane contact. Several approaches exist to individually visualize terminal SCs. None of these are flawless, though. For instance, dye filling, where single cells are impaled with a dye-filled microelectrode, requires destroying a labelled cell before filling a second one. This is not compatible with subsequent time-lapse recordings. Multi-spectral "Brainbow" labeling of SCs has been achieved by using combinatorial expression of fluorescent proteins. However, this technique requires combining several transgenes and is limited by the expression pattern of the promoters used. In the future, expression of "photo-switchable" proteins in SCs might be yet another alternative. Here we present sequential photo-bleaching, where single cells are bleached, and their image obtained by subtraction. We believe that this approach - due to its ease and versatility - represents a lasting addition to the neuroscientist's technology palette, especially as it can be used in vivo and transferred to others cell types, anatomical sites or species. In the following protocol, we detail the application of sequential bleaching and subsequent confocal time-lapse microscopy to terminal SCs in triangularis sterni muscle explants. This thin, superficial and easily dissected nerve-muscle preparation has proven useful for studies of NMJ development, physiology and pathology. Finally, we explain how the triangularis sterni muscle is prepared after fixation to perform correlated high-resolution confocal imaging, immunohistochemistry or ultrastructural examinations.

Distribution of serine/threonine kinase SAD-B in mouse peripheral nerve synapse.

PubMed

Hagiwara, Akari; Harada, Kenu; Hida, Yamato; Kitajima, Isao; Ohtsuka, Toshihisa

2011-05-11

The serine/threonine kinase SAD regulates neural functions such as axon/dendrite polarization and neurotransmitter release. In the vertebrate central nervous system, SAD-B, a homolog of Caenorhabditis elegans SAD-1, is associated with synaptic vesicles and the active zone cytomatrix in nerve terminals. However, the distribution of SAD-B in the peripheral nervous system remains elusive. Here, we show that SAD-B is specifically localized to neuromuscular junctions. Although the active zone protein bassoon showed a punctated signal indicating its localization to motor end plates, SAD-B shows relatively diffuse localization indicating its association with both the active zone and synaptic vesicles. Therefore, SAD kinase may regulate neurotransmitter release from motor end plates in a similar manner to its regulation of neurotransmitter release in the central nervous system.

49 CFR 1242.27 - Coal marine terminals, ore marine terminals, TOFC/COFC terminals, other marine terminals, motor...

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 9 2014-10-01 2014-10-01 false Coal marine terminals, ore marine terminals, TOFC/COFC terminals, other marine terminals, motor vehicle loading and distribution facilities, and... Structures § 1242.27 Coal marine terminals, ore marine terminals, TOFC/COFC terminals, other marine terminals...

49 CFR 1242.27 - Coal marine terminals, ore marine terminals, TOFC/COFC terminals, other marine terminals, motor...

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 9 2013-10-01 2013-10-01 false Coal marine terminals, ore marine terminals, TOFC/COFC terminals, other marine terminals, motor vehicle loading and distribution facilities, and... Structures § 1242.27 Coal marine terminals, ore marine terminals, TOFC/COFC terminals, other marine terminals...

49 CFR 1242.27 - Coal marine terminals, ore marine terminals, TOFC/COFC terminals, other marine terminals, motor...

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 9 2012-10-01 2012-10-01 false Coal marine terminals, ore marine terminals, TOFC/COFC terminals, other marine terminals, motor vehicle loading and distribution facilities, and... Structures § 1242.27 Coal marine terminals, ore marine terminals, TOFC/COFC terminals, other marine terminals...

49 CFR 1242.27 - Coal marine terminals, ore marine terminals, TOFC/COFC terminals, other marine terminals, motor...

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 9 2011-10-01 2011-10-01 false Coal marine terminals, ore marine terminals, TOFC/COFC terminals, other marine terminals, motor vehicle loading and distribution facilities, and... Structures § 1242.27 Coal marine terminals, ore marine terminals, TOFC/COFC terminals, other marine terminals...

49 CFR 1242.27 - Coal marine terminals, ore marine terminals, TOFC/COFC terminals, other marine terminals, motor...

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 9 2010-10-01 2010-10-01 false Coal marine terminals, ore marine terminals, TOFC/COFC terminals, other marine terminals, motor vehicle loading and distribution facilities, and... Structures § 1242.27 Coal marine terminals, ore marine terminals, TOFC/COFC terminals, other marine terminals...

The terminator mouse: salvation for primary cell culture.

PubMed

Kabgani, Nazanin; Moeller, Marcus J

2013-11-01

The Terminator had to come back from the future already several times in an effort to bring salvation to mankind. In the present issue of Kidney International, Guo et al. brought us a novel transgenic mouse model: the terminator mouse. This highly elegant mouse may facilitate significantly the derivation of primary cultures of a specific cell type from a tissue containing multiple cell populations.

Single Body Parts are Processed by Individual Neurons in the Mouse Dorsolateral Striatum

PubMed Central

Coffey, Kevin R.; Nader, Miles; West, Mark O.

2016-01-01

Interest in the dorsolateral striatum (DLS) has generated numerous scientific studies of its neuropathologies, as well as its roles in normal sensorimotor integration and learning. Studies are informed by knowledge of DLS functional organization, the guiding principle being its somatotopic afferent projections from primary somatosensory (S1) and motor (M1) cortices. The potential to connect behaviorally relevant function to detailed structure is elevated by mouse models, which have access to extensive genetic neuroscience tool kits. Remaining to be demonstrated, however, is whether the correspondence between S1/M1 corticostriatal terminal distributions and the physiological properties of DLS neurons demonstrated in rats and non-human primates exists in mice. Given that the terminal distribution of S1/M1 projections to the DLS in mice is similar to that in rats, we studied whether firing rates (FRs) of DLS neurons in awake, behaving mice are related to activity of individual body parts. MSNs exhibited robust, selective increases in FR during movement or somatosensory stimulation of single body parts. Properties of MSNs, including baseline FRs, locations, responsiveness to stimulation, and proportions of responsive neurons were similar to properties observed in rats. Future studies can be informed by the present demonstration that the mouse lateral striatum functions as a somatic sensorimotor sector of the striatum and appears to be a homolog of the primate putamen, as demonstrated in rats (Carelli and West, 1991). PMID:26827625

Morphology of the lumbar transversospinal muscles examined in a mouse bearing a muscle fiber-specific nuclear marker.

PubMed

Cornwall, Jon; Deries, Marianne; Duxson, Marilyn

2010-12-01

Although the morphology of human lumbar transversospinal (TSP) muscles has been studied, little is known about the structure of these muscles in the mouse (Mus musculus). Such information is relevant given mice are often used as a "normal" phenotype for studies modeling human development. This study describes the gross morphology, muscle fiber arrangement, and innervation pattern of the mouse lumbar TSP muscles. A unique feature of the study is the use of a transgenic mouse line bearing a muscle-specific nuclear marker that allows clear delineation of muscle fiber and connective tissue boundaries. The lumbar TSP muscles of five mice were examined bilaterally; at each spinal level muscles attached to the caudal edge of the spinous process and passed caudally as a single complex unit. Fibers progressively terminated over the four vertebral segments caudad, with multiple points of muscle fiber attachment on each vertebra. Motor endplates, defined with acetylcholinesterase histochemistry, were consistently located half way along each muscle fiber, regardless of length, with all muscle fibers arranged in-parallel rather than in-series. These results provide information relevant to interpretation of developmental and functional studies involving this muscle group in the mouse and show mouse lumbar TSP muscles are different in form to descriptions of equivalent muscles in humans and horses.

Striatal Direct and Indirect Pathway Output Structures are Differentially Altered in Mouse Models of Huntington's Disease.

PubMed

Barry, Joshua; Akopian, Garnik; Cepeda, Carlos; Levine, Michael S

2018-04-24

The present study examined synaptic communication between direct and indirect output pathway striatal medium-sized spiny neurons (MSNs) and their target structures, the substantia nigra pars reticulata (SNr) and the external globus pallidus (GPe) in two mouse models of Huntington's disease (HD). Cre-recombination, optogenetics, and whole-cell patch clamp recordings were used to determine alterations in intrinsic and synaptic properties of SNr and GPe neurons from both male and female symptomatic R6/2 (>60 days) and pre- (2 months) or symptomatic (10-12 months) YAC128 mice. Cell membrane capacitance was decreased whereas input resistance was increased in SNr neurons from R6/2, but not YAC128 mice. The amplitude of GABAergic responses evoked by optogenetic stimulation of direct pathway terminals was reduced in SNr neurons of symptomatic mice of both models. A decrease in spontaneous GABA synaptic activity, in particular large-amplitude events, in SNr neurons also was observed. Passive membrane properties of GPe neurons were not different between R6/2 or YAC128 mice and their control littermates. Similarly, the amplitude of GABA responses evoked by activation of indirect pathway MSN terminals and the frequency of spontaneous GABA synaptic activity were similar in HD and control animals. In contrast, the decay time of the evoked GABA response was significantly longer in cells from HD mice. Interestingly, activation of indirect pathway MSNs within the striatum evoked larger-amplitude responses in direct pathway MSNs. Together, these results demonstrate differential alterations in responses evoked by direct and indirect pathway terminals in SNr and GPe leading to striatal output imbalance and motor dysfunction. SIGNIFICANCE STATEMENT Previous work on Huntington's disease (HD) focused on striatal medium-sized spiny neurons (MSNs) almost exclusively. Little is known about the effects that alterations in the striatum have on output structures of the direct and indirect pathways, the substantia nigra pars reticulata (SNr) and the external segment of the globus pallidus (GPe), respectively. We combined electrophysiological and optogenetic methods to examine responses evoked by selective activation of terminals of direct and indirect pathway MSNs in SNr and GPe neurons in two mouse models of HD. We show a differential disruption of synaptic communication between the direct and indirect output pathways of the striatum with their target regions leading to an imbalance of striatal output, which will contribute to motor dysfunction. Copyright © 2018 the authors.

The Terminator mouse is a diphtheria toxin-receptor knock-in mouse strain for rapid and efficient enrichment of desired cell lineages.

PubMed

Guo, Jian-Kan; Shi, Hongmei; Koraishy, Farrukh; Marlier, Arnaud; Ding, Zhaowei; Shan, Alan; Cantley, Lloyd G

2013-11-01

Biomedical research often requires primary cultures of specific cell types, which are challenging to obtain at high purity in a reproducible manner. Here we engineered the murine Rosa26 locus by introducing the diphtheria toxin receptor flanked by loxP sites. The resultant strain was nicknamed the Terminator mouse. This approach results in diphtheria toxin-receptor expression in all non-Cre expressing cell types, making these cells susceptible to diphtheria toxin exposure. In primary cultures of kidney cells derived from the Terminator mouse, over 99.99% of cells were dead within 72 h of diphtheria toxin treatment. After crossing the Terminator with the podocin-Cre (podocyte specific) mouse or the Ggt-Cre (proximal tubule specific) mouse, diphtheria toxin treatment killed non-Cre expressing cells but spared podocytes and proximal tubule cells, respectively, enriching the primary cultures to over 99% purity, based on both western blotting and immunostaining of marker proteins. Thus, the Terminator mouse can be a useful tool to selectively and reproducibly obtain even low-abundant cell types at high quantity and purity.

Assisting People with Multiple Disabilities and Minimal Motor Behavior to Control Environmental Stimulation through a Mouse Wheel

ERIC Educational Resources Information Center

Shih, Ching-Hsiang; Shih, Ching-Tien; Lin, Kun-Tsan; Chiang, Ming-Shan

2009-01-01

This study assessed whether two people with profound multiple disabilities and minimal motor behavior would be able to control environmental stimulation using thumb poke ability with a mouse wheel and a newly developed mouse driver (i.e., a new mouse driver replacing standard mouse driver, and turning a mouse into a precise thumb poke detector).…

Stimulation-induced Ca(2+) influx at nodes of Ranvier in mouse peripheral motor axons.

PubMed

Zhang, Zhongsheng; David, Gavriel

2016-01-01

In peripheral myelinated axons of mammalian spinal motor neurons, Ca(2+) influx was thought to occur only in pathological conditions such as ischaemia. Using Ca(2+) imaging in mouse large motor axons, we find that physiological stimulation with trains of action potentials transiently elevates axoplasmic [C(2+)] around nodes of Ranvier. These stimulation-induced [Ca(2+)] elevations require Ca(2+) influx, and are partially reduced by blocking T-type Ca(2+) channels (e.g. mibefradil) and by blocking the Na(+)/Ca(2+) exchanger (NCX), suggesting an important contribution of Ca(2+) influx via reverse-mode NCX activity. Acute disruption of paranodal myelin dramatically increases stimulation-induced [Ca(2+)] elevations around nodes by allowing activation of sub-myelin L-type (nimodipine-sensitive) Ca(2+) channels. The Ca(2+) that enters myelinated motor axons during normal activity is likely to contribute to several signalling pathways; the larger Ca(2+) influx that occurs following demyelination may contribute to the axonal degeneration that occurs in peripheral demyelinating diseases. Activity-dependent Ca(2+) signalling is well established for somata and terminals of mammalian spinal motor neurons, but not for their axons. Imaging of an intra-axonally injected fluorescent [Ca(2+)] indicator revealed that during repetitive action potential stimulation, [Ca(2+)] elevations localized to nodal regions occurred in mouse motor axons from ventral roots, phrenic nerve and intramuscular branches. These [Ca(2+)] elevations (∼ 0.1 μm with stimulation at 50 Hz, 10 s) were blocked by removal of Ca(2+) from the extracellular solution. Effects of pharmacological blockers indicated contributions from both T-type Ca(2+) channels and reverse mode Na(+)/Ca(2+) exchange (NCX). Acute disruption of paranodal myelin (by stretch or lysophosphatidylcholine) increased the stimulation-induced [Ca(2+)] elevations, which now included a prominent contribution from L-type Ca(2+) channels. These results suggest that the peri-nodal axolemma of motor axons includes multiple pathways for stimulation-induced Ca(2+) influx, some active in normally-myelinated axons (T-type channels, NCX), others active only when exposed by myelin disruption (L-type channels). The modest axoplasmic peri-nodal [Ca(2+)] elevations measured in intact motor axons might mediate local responses to axonal activation. The larger [Ca(2+) ] elevations measured after myelin disruption might, over time, contribute to the axonal degeneration observed in peripheral demyelinating neuropathies. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

Molecular coevolution of mammalian ribosomal gene terminator sequences and the transcription termination factor TTF-I.

PubMed Central

Evers, R; Grummt, I

1995-01-01

Both the DNA elements and the nuclear factors that direct termination of ribosomal gene transcription exhibit species-specific differences. Even between mammals--e.g., human and mouse--the termination signals are not identical and the respective transcription termination factors (TTFs) which bind to the terminator sequence are not fully interchangeable. To elucidate the molecular basis for this species-specificity, we have cloned TTF-I from human and mouse cells and compared their structural and functional properties. Recombinant TTF-I exhibits species-specific DNA binding and terminates transcription both in cell-free transcription assays and in transfection experiments. Chimeric constructs of mouse TTF-I and human TTF-I reveal that the major determinant for species-specific DNA binding resides within the C terminus of TTF-I. Replacing 31 C-terminal amino acids of mouse TTF-I with the homologous human sequences relaxes the DNA-binding specificity and, as a consequence, allows the chimeric factor to bind the human terminator sequence and to specifically stop rDNA transcription. Images Fig. 2 Fig. 3 Fig. 4 PMID:7597036

Mechanics of mouse ocular motor plant quantified by optogenetic techniques.

PubMed

Stahl, John S; Thumser, Zachary C; May, Paul J; Andrade, Francisco H; Anderson, Sean R; Dean, Paul

2015-09-01

Rigorous descriptions of ocular motor mechanics are often needed for models of ocular motor circuits. The mouse has become an important tool for ocular motor studies, yet most mechanical data come from larger species. Recordings of mouse abducens neurons indicate the mouse mechanics share basic viscoelastic properties with larger species but have considerably longer time constants. Time constants can also be extracted from the rate at which the eye re-centers when released from an eccentric position. The displacement can be accomplished by electrically stimulating ocular motor nuclei, but electrical stimulation may also activate nearby ocular motor circuitry. We achieved specific activation of abducens motoneurons through photostimulation in transgenic mice expressing channelrhodopsin in cholinergic neurons. Histology confirmed strong channelrhodopsin expression in the abducens nucleus with relatively little expression in nearby ocular motor structures. Stimulation was delivered as 20- to 1,000-ms pulses and 40-Hz trains. Relaxations were modeled best by a two-element viscoelastic system. Time constants were sensitive to stimulus duration. Analysis of isometric relaxation of isolated mouse extraocular muscles suggest the dependence is attributable to noninstantaneous decay of active forces in non-twitch fibers following stimulus offset. Time constants were several times longer than those obtained in primates, confirming that the mouse ocular motor mechanics are relatively sluggish. Finally, we explored the effects of 0.1- to 20-Hz sinusoidal photostimuli and demonstrated their potential usefulness in characterizing ocular motor mechanics, although this application will require further data on the temporal relationship between photostimulation and neuronal firing in extraocular motoneurons.

Single body parts are processed by individual neurons in the mouse dorsolateral striatum.

PubMed

Coffey, Kevin R; Nader, Miles; West, Mark O

2016-04-01

Interest in the dorsolateral striatum (DLS) has generated numerous scientific studies of its neuropathologies, as well as its roles in normal sensorimotor integration and learning. Studies are informed by knowledge of DLS functional organization, the guiding principle being its somatotopic afferent projections from primary somatosensory (S1) and motor (M1) cortices. The potential to connect behaviorally relevant function to detailed structure is elevated by mouse models, which have access to extensive genetic neuroscience tool kits. Remaining to be demonstrated, however, is whether the correspondence between S1/M1 corticostriatal terminal distributions and the physiological properties of DLS neurons demonstrated in rats and non-human primates exists in mice. Given that the terminal distribution of S1/M1 projections to the DLS in mice is similar to that in rats, we studied whether firing rates (FRs) of DLS neurons in awake, behaving mice are related to activity of individual body parts. MSNs exhibited robust, selective increases in FR during movement or somatosensory stimulation of single body parts. Properties of MSNs, including baseline FRs, locations, responsiveness to stimulation, and proportions of responsive neurons were similar to properties observed in rats. Future studies can be informed by the present demonstration that the mouse lateral striatum functions as a somatic sensorimotor sector of the striatum and appears to be a homolog of the primate putamen, as demonstrated in rats (Carelli and West, 1991). Copyright © 2016 Elsevier B.V. All rights reserved.

Assisting People with Multiple Disabilities and Minimal Motor Behavior to Improve Computer Pointing Efficiency through a Mouse Wheel

ERIC Educational Resources Information Center

Shih, Ching-Hsiang; Chang, Man-Ling; Shih, Ching-Tien

2009-01-01

This study evaluated whether two people with multiple disabilities and minimal motor behavior would be able to improve their pointing performance using finger poke ability with a mouse wheel through a Dynamic Pointing Assistive Program (DPAP) and a newly developed mouse driver (i.e., a new mouse driver replaces standard mouse driver, changes a…

A unified model of the excitability of mouse sensory and motor axons.

PubMed

Makker, Preet G S; Matamala, José Manuel; Park, Susanna B; Lees, Justin G; Kiernan, Matthew C; Burke, David; Moalem-Taylor, Gila; Howells, James

2018-06-19

Non-invasive nerve excitability techniques have provided valuable insight into the understanding of neurological disorders. The widespread use of mice in translational research on peripheral nerve disorders and by pharmaceutical companies during drug development requires valid and reliable models that can be compared to humans. This study established a novel experimental protocol that enables comparative assessment of the excitability properties of motor and sensory axons at the same site in mouse caudal nerve, compared the mouse data to data for motor and sensory axons in human median nerve at the wrist, and constructed a mathematical model of the excitability of mouse axons. In a separate study, ischaemia was employed as an experimental manoeuvre to test the translational utility of this preparation. The patterns of mouse sensory and motor excitability were qualitatively similar to human studies under normal and ischaemic conditions. The most conspicuous differences between mouse and human studies were observed in the recovery cycle and the response to hyperpolarization. Modelling showed that an increase in temperature in mouse axons could account for most of the differences in the recovery cycle. The modelling also suggested a larger hyperpolarization-activated conductance in mouse axons. The kinetics of this conductance appeared to be much slower raising the possibility that an additional or different hyperpolarization-activated cyclic-nucleotide gated (HCN) channel isoform underlies the accommodation to hyperpolarization in mouse axons. Given a possible difference in HCN isoforms, caution should be exercised in extrapolating from studies of mouse motor and sensory axons to human nerve disorders. This article is protected by copyright. All rights reserved.

Characterization of motor units in behaving adult mice shows a wide primary range

PubMed Central

Ritter, Laura K.; Tresch, Matthew C.; Heckman, C. J.; Manuel, Marin

2014-01-01

The mouse is essential for genetic studies of motor function in both normal and pathological states. Thus it is important to consider whether the structure of motor output from the mouse is in fact analogous to that recorded in other animals. There is a striking difference in the basic electrical properties of mouse motoneurons compared with those in rats, cats, and humans. The firing evoked by injected currents produces a unique frequency-current (F-I) function that emphasizes recruitment of motor units at their maximum force. These F-I functions, however, were measured in anesthetized preparations that lacked two key components of normal synaptic input: high levels of synaptic noise and neuromodulatory inputs. Recent studies suggest that the alterations in the F-I function due to these two components are essential for recreating firing behavior of motor units in human subjects. In this study we provide the first data on firing patterns of motor units in the awake mouse, focusing on steady output in quiet stance. The resulting firing patterns did not match the predictions from the mouse F-I behaviors but instead revealed rate modulation across a remarkably wide range (10–60 Hz). The low end of the firing range may be due to changes in the F-I relation induced by synaptic noise and neuromodulatory inputs. The high end of the range may indicate that, unlike other species, quiet standing in the mouse involves recruitment of relatively fast-twitch motor units. PMID:24805075

Characterization of motor units in behaving adult mice shows a wide primary range.

PubMed

Ritter, Laura K; Tresch, Matthew C; Heckman, C J; Manuel, Marin; Tysseling, Vicki M

2014-08-01

The mouse is essential for genetic studies of motor function in both normal and pathological states. Thus it is important to consider whether the structure of motor output from the mouse is in fact analogous to that recorded in other animals. There is a striking difference in the basic electrical properties of mouse motoneurons compared with those in rats, cats, and humans. The firing evoked by injected currents produces a unique frequency-current (F-I) function that emphasizes recruitment of motor units at their maximum force. These F-I functions, however, were measured in anesthetized preparations that lacked two key components of normal synaptic input: high levels of synaptic noise and neuromodulatory inputs. Recent studies suggest that the alterations in the F-I function due to these two components are essential for recreating firing behavior of motor units in human subjects. In this study we provide the first data on firing patterns of motor units in the awake mouse, focusing on steady output in quiet stance. The resulting firing patterns did not match the predictions from the mouse F-I behaviors but instead revealed rate modulation across a remarkably wide range (10-60 Hz). The low end of the firing range may be due to changes in the F-I relation induced by synaptic noise and neuromodulatory inputs. The high end of the range may indicate that, unlike other species, quiet standing in the mouse involves recruitment of relatively fast-twitch motor units. Copyright © 2014 the American Physiological Society.

In-vivo effects of knocking-down metabotropic glutamate receptor 5 in the SOD1G93A mouse model of amyotrophic lateral sclerosis.

PubMed

Bonifacino, Tiziana; Cattaneo, Luca; Gallia, Elena; Puliti, Aldamaria; Melone, Marcello; Provenzano, Francesca; Bossi, Simone; Musante, Ilaria; Usai, Cesare; Conti, Fiorenzo; Bonanno, Giambattista; Milanese, Marco

2017-09-01

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder due to loss of upper and lower motor neurons (MNs). The mechanisms of neuronal death are largely unknown, thus prejudicing the successful pharmacological treatment. One major cause for MN degeneration in ALS is represented by glutamate(Glu)-mediated excitotoxicity. We have previously reported that activation of Group I metabotropic Glu receptors (mGluR1 and mGluR5) at glutamatergic spinal cord nerve terminals produces abnormal Glu release in the widely studied SOD1 G93A mouse model of ALS. We also demonstrated that halving mGluR1 expression in the SOD1 G93A mouse had a positive impact on survival, disease onset, disease progression, and on a number of cellular and biochemical readouts of ALS. We generated here SOD1 G93A mice with reduced expression of mGluR5 (SOD1 G93A Grm5 -/+ ) by crossing the SOD1 G93A mutant mouse with the mGluR5 heterozigous Grm5 -/+ mouse. SOD1 G93A Grm5 -/+ mice showed prolonged survival probability and delayed pathology onset. These effects were associated to enhanced number of preserved MNs, decreased astrocyte and microglia activation, reduced cytosolic free Ca 2+ concentration, and regularization of abnormal Glu release in the spinal cord of SOD1 G93A Grm5 -/+ mice. Unexpectedly, only male SOD1 G93A Grm5 -/+ mice showed improved motor skills during disease progression vs. SOD1 G93A mice, while SOD1 G93A Grm5 -/+ females did not. These results demonstrate that a lower constitutive level of mGluR5 has a significant positive impact in mice with ALS and support the idea that blocking Group I mGluRs may represent a potentially effective pharmacological approach to the disease. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cloning and determination of the transcription termination site of ribosomal RNA gene of the mouse.

PubMed Central

Kominami, R; Mishima, Y; Urano, Y; Sakai, M; Muramatsu, M

1982-01-01

A Eco RI 6.6 kb DNA fragment containing the 3'-end of 28S ribosomal RNA gene of the mouse was detected by Southern blot hybridization, and cloned in a lambda-phage vector. The site of transcription termination and the processed 3'-end of 28S RNA were determined on the cloned fragment and the surrounding nucleotide sequence determined. The 3'-terminal nucleotides of mouse 28S RNA are similar to those of yeast, Drosophila and Xenopus although the homology was lost drastically beyond the 3'-end of 28S RNA. 45S precursor RNA terminated at 30 nucleotides downstream from the 3'-end of 28S RNA gene. A structure of a dyad symmetry with a loop was found immediately prior to the termination site of 45S RNA. The rDNA termination site thus shares some common features with termination sites recognized by other RNA polymerases. Images PMID:6281727

Identified motor terminals in Drosophila larvae show distinct differences in morphology and physiology

NASA Technical Reports Server (NTRS)

Lnenicka, G. A.; Keshishian, H.

2000-01-01

In Drosophila, the type I motor terminals innervating the larval ventral longitudinal muscle fibers 6 and 7 have been the most popular preparation for combining synaptic studies with genetics. We have further characterized the normal morphological and physiological properties of these motor terminals and the influence of muscle size on terminal morphology. Using dye-injection and physiological techniques, we show that the two axons supplying these terminals have different innervation patterns: axon 1 innervates only muscle fibers 6 and 7, whereas axon 2 innervates all of the ventral longitudinal muscle fibers. This difference in innervation pattern allows the two axons to be reliably identified. The terminals formed by axons 1 and 2 on muscle fibers 6 and 7 have the same number of branches; however, axon 2 terminals are approximately 30% longer than axon 1 terminals, resulting in a corresponding greater number of boutons for axon 2. The axon 1 boutons are approximately 30% wider than the axon 2 boutons. The excitatory postsynaptic potential (EPSP) produced by axon 1 is generally smaller than that produced by axon 2, although the size distributions show considerable overlap. Consistent with vertebrate studies, there is a correlation between muscle fiber size and terminal size. For a single axon, terminal area and length, the number of terminal branches, and the number of boutons are all correlated with muscle fiber size, but bouton size is not. During prolonged repetitive stimulation, axon 2 motor terminals show synaptic depression, whereas axon 1 EPSPs facilitate. The response to repetitive stimulation appears to be similar at all motor terminals of an axon. Copyright 2000 John Wiley & Sons, Inc.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ding, Ying; Adachi, Hiroaki, E-mail: hadachi-ns@umin.org; Department of Neurology, University of Occupational and Environmental Health School of Medicine, 1-1 Iseigaoka, Yahata-nishi-ku, Kitakyushu 807-8555

Spinal and bulbar muscular atrophy (SBMA) is an inherited motor neuron disease caused by the expansion of a polyglutamine (polyQ)-encoding tract within the androgen receptor (AR) gene. The pathologic features of SBMA are motor neuron loss in the spinal cord and brainstem and diffuse nuclear accumulation and nuclear inclusions of mutant AR in residual motor neurons and certain visceral organs. Hepatocyte growth factor (HGF) is a polypeptide growth factor which has neuroprotective properties. To investigate whether HGF overexpression can affect disease progression in a mouse model of SBMA, we crossed SBMA transgenic model mice expressing an AR gene with anmore » expanded CAG repeat with mice overexpressing HGF. Here, we report that high expression of HGF induces Akt phosphorylation and modestly ameliorated motor symptoms in an SBMA transgenic mouse model treated with or without castration. These findings suggest that HGF overexpression can provide a potential therapeutic avenue as a combination therapy with disease-modifying therapies in SBMA. - Highlights: • HGF overexpression ameliorates the motor phenotypes of the SBMA mouse model. • HGF overexpression induces Akt phosphorylation in the SBMA mouse model. • This is the first report of combination therapy in a mouse model of polyQ diseases.« less

Immunohistochemical localization of the NH(2)-terminal and COOH-terminal fragments of dentin sialoprotein in mouse teeth.

PubMed

Yuan, Guohua; Yang, Guobin; Song, Guangtai; Chen, Zhi; Chen, Shuo

2012-08-01

Dentin sialoprotein (DSP) is a major non-collagenous protein in dentin. Mutation studies in human, along with gene knockout and transgenic experiments in mice, have confirmed the critical role of DSP for dentin formation. Our previous study reported that DSP is processed into fragments in mouse odontoblast-like cells. In order to gain insights into the function of DSP fragments, we further evaluated the expression pattern of DSP in the mouse odontoblast-like cells using immunohistochemistry and western blot assay with antibodies against the NH(2)-terminal and COOH-terminal regions of DSP. Then, the distribution profiles of the DSP NH(2)-terminal and COOH-terminal fragments and osteopontin (OPN) were investigated in mouse teeth at different ages by immunohistochemistry. In the odontoblast-like cells, multiple low molecular weight DSP fragments were detected, suggesting that part of the DSP protein was processed in the odontoblast-like cells. In mouse first lower molars, immunoreactions for anti-DSP-NH(2) antibody were intense in the predentin matrix but weak in mineralized dentin; in contrast, for anti-DSP-COOH antibody, strong immunoreactions were found in mineralized dentin, in particular dentinal tubules but weak in predentin. Therefore, DSP NH(2)-terminal and COOH-terminal fragments from odontoblasts were secreted to different parts of teeth, suggesting that they may play distinct roles in dentinogenesis. Meanwhile, both DSP antibodies showed weak staining in reactionary dentin (RD), whereas osteopontin (OPN) was clearly positive in RD. Therefore, DSP may be less crucial for RD formation than OPN.

Immunohistochemical localization of the NH2-terminal and COOH-terminal fragments of dentin sialoprotein in mouse teeth

PubMed Central

Yuan, Guohua; Yang, Guobin; Song, Guangtai

2013-01-01

Dentin sialoprotein (DSP) is a major non-collagenous protein in dentin. Mutation studies in human, along with gene knockout and transgenic experiments in mice, have confirmed the critical role of DSP for dentin formation. Our previous study reported that DSP is processed into fragments in mouse odontoblast-like cells. In order to gain insights into the function of DSP fragments, we further evaluated the expression pattern of DSP in the mouse odontoblast-like cells using immunohistochemistry and western blot assay with antibodies against the NH2-terminal and COOH-terminal regions of DSP. Then, the distribution profiles of the DSP NH2-terminal and COOH-terminal fragments and osteopontin (OPN) were investigated in mouse teeth at different ages by immunohistochemistry. In the odontoblast-like cells, multiple low molecular weight DSP fragments were detected, suggesting that part of the DSP protein was processed in the odontoblast-like cells. In mouse first lower molars, immunoreactions for anti-DSP-NH2 antibody were intense in the predentin matrix but weak in mineralized dentin; in contrast, for anti-DSP-COOH antibody, strong immunoreactions were found in mineralized dentin, in particular dentinal tubules but weak in predentin. Therefore, DSP NH2-terminal and COOH-terminal fragments from odontoblasts were secreted to different parts of teeth, suggesting that they may play distinct roles in dentinogenesis. Meanwhile, both DSP antibodies showed weak staining in reactionary dentin (RD), whereas osteopontin (OPN) was clearly positive in RD. Therefore, DSP may be less crucial for RD formation than OPN. PMID:22581382

A Circuit for Motor Cortical Modulation of Auditory Cortical Activity

PubMed Central

Nelson, Anders; Schneider, David M.; Takatoh, Jun; Sakurai, Katsuyasu; Wang, Fan

2013-01-01

Normal hearing depends on the ability to distinguish self-generated sounds from other sounds, and this ability is thought to involve neural circuits that convey copies of motor command signals to various levels of the auditory system. Although such interactions at the cortical level are believed to facilitate auditory comprehension during movements and drive auditory hallucinations in pathological states, the synaptic organization and function of circuitry linking the motor and auditory cortices remain unclear. Here we describe experiments in the mouse that characterize circuitry well suited to transmit motor-related signals to the auditory cortex. Using retrograde viral tracing, we established that neurons in superficial and deep layers of the medial agranular motor cortex (M2) project directly to the auditory cortex and that the axons of some of these deep-layer cells also target brainstem motor regions. Using in vitro whole-cell physiology, optogenetics, and pharmacology, we determined that M2 axons make excitatory synapses in the auditory cortex but exert a primarily suppressive effect on auditory cortical neuron activity mediated in part by feedforward inhibition involving parvalbumin-positive interneurons. Using in vivo intracellular physiology, optogenetics, and sound playback, we also found that directly activating M2 axon terminals in the auditory cortex suppresses spontaneous and stimulus-evoked synaptic activity in auditory cortical neurons and that this effect depends on the relative timing of motor cortical activity and auditory stimulation. These experiments delineate the structural and functional properties of a corticocortical circuit that could enable movement-related suppression of auditory cortical activity. PMID:24005287

HERC1 Ubiquitin Ligase Is Required for Normal Axonal Myelination in the Peripheral Nervous System.

PubMed

Bachiller, Sara; Roca-Ceballos, María Angustias; García-Domínguez, Irene; Pérez-Villegas, Eva María; Martos-Carmona, David; Pérez-Castro, Miguel Ángel; Real, Luis Miguel; Rosa, José Luis; Tabares, Lucía; Venero, José Luis; Armengol, José Ángel; Carrión, Ángel Manuel; Ruiz, Rocío

2018-03-30

A missense mutation in HERC1 provokes loss of cerebellar Purkinje cells, tremor, and unstable gait in tambaleante (tbl) mice. Recently, we have shown that before cerebellar degeneration takes place, the tbl mouse suffers from a reduction in the number of vesicles available for release at the neuromuscular junction (NMJ). The aim of the present work was to study to which extent the alteration in HERC1 may affect other cells in the nervous system and how this may influence the motor dysfunction observed in these mice. The functional analysis showed a consistent delay in the propagation of the action potential in mutant mice in comparison with control littermates. Morphological analyses of glial cells in motor axons revealed signs of compact myelin damage as tomacula and local hypermyelination foci. Moreover, we observed an alteration in non-myelinated terminal Schwann cells at the level of the NMJ. Additionally, we found a significant increment of phosphorylated Akt-2 in the sciatic nerve. Based on these findings, we propose a molecular model that could explain how mutated HERC1 in tbl mice affects the myelination process in the peripheral nervous system. Finally, since the myelin abnormalities found in tbl mice are histological hallmarks of neuropathic periphery diseases, tbl mutant mice could be considered as a new mouse model for this type of diseases.

A Longitudinal Motor Characterisation of the HdhQ111 Mouse Model of Huntington's Disease.

PubMed

Yhnell, Emma; Dunnett, Stephen B; Brooks, Simon P

2016-05-31

Huntington's disease (HD) is a rare, incurable neurodegenerative disorder caused by a CAG trinucleotide expansion with the first exon of the huntingtin gene. Numerous knock-in mouse models are currently available for modelling HD. However, before their use in scientific research, these models must be characterised to determine their face and predictive validity as models of the disease and their reliability in recapitulating HD symptoms. Manifest HD is currently diagnosed upon the onset of motor symptoms, thus we sought to longitudinally characterise the progression and severity of motor signs in the HdhQ111 knock-in mouse model of HD, in heterozygous mice. An extensive battery of motor tests including: rotarod, inverted lid test, balance beam, spontaneous locomotor activity and gait analysis were applied longitudinally to a cohort of HdhQ111 heterozygous mice in order to progressively assess motor function. A progressive failure to gain body weight was demonstrated from 11 months of age and motor problems in all measures of balance beam performance were shown in HdhQ111 heterozygous animals in comparison to wild type control animals from 9 months of age. A decreased latency to fall from the rotarod was demonstrated in HdhQ111 heterozygous animals in comparison to wild type animals, although this was not progressive with time. No genotype specific differences were demonstrated in any of the other motor tests included in the test battery. The HdhQ111 heterozygous mouse demonstrates a subtle and progressive motor phenotype that begins at 9 months of age. This mouse model represents an early disease stage and would be ideal for testing therapeutic strategies that require elongated lead-in times, such as viral gene therapies or striatal transplantation.

Architecture of Vagal Motor Units Controlling Striated Muscle of Esophagus: Peripheral Elements Patterning Peristalsis?

PubMed Central

Powley, Terry L.; Mittal, Ravinder K.; Baronowsky, Elizabeth A.; Hudson, Cherie N.; Martin, Felecia N.; McAdams, Jennifer L.; Mason, Jacqueline K.; Phillips, Robert J.

2013-01-01

Little is known about the architecture of the vagal motor units that control esophageal striated muscle, in spite of the fact that these units are necessary, and responsible, for peristalsis. The present experiment was designed to characterize the motor neuron projection fields and terminal arbors forming esophageal motor units. Nucleus ambiguus compact formation neurons of the rat were labeled by bilateral intracranial injections of the anterograde tracer dextran biotin. After tracer transport, thoracic and abdominal esophagi were removed and prepared as whole mounts of muscle wall without mucosa or submucosa. Labeled terminal arbors of individual vagal motor neurons (n = 78) in the esophageal wall were inventoried, digitized and analyzed morphometrically. The size of individual vagal motor units innervating striated muscle, throughout thoracic and abdominal esophagus, averaged 52 endplates per motor neuron, a value indicative of fine motor control. A majority (77%) of the motor terminal arbors also issued one or more collateral branches that contacted neurons, including nitric oxide synthase-positive neurons, of local myenteric ganglia. Individual motor neuron terminal arbors co-innervated, or supplied endplates in tandem to, both longitudinal and circular muscle fibers in roughly similar proportions (i.e., two endplates to longitudinal for every three endplates to circular fibers). Both the observation that vagal motor unit collaterals project to myenteric ganglia and the fact that individual motor units co-innervate longitudinal and circular muscle layers are consistent with the hypothesis that elements contributing to peristaltic programming inhere, or are “hardwired,” in the peripheral architecture of esophageal motor units. PMID:24044976

Architecture of vagal motor units controlling striated muscle of esophagus: peripheral elements patterning peristalsis?

PubMed

Powley, Terry L; Mittal, Ravinder K; Baronowsky, Elizabeth A; Hudson, Cherie N; Martin, Felecia N; McAdams, Jennifer L; Mason, Jacqueline K; Phillips, Robert J

2013-12-01

Little is known about the architecture of the vagal motor units that control esophageal striated muscle, in spite of the fact that these units are necessary, and responsible, for peristalsis. The present experiment was designed to characterize the motor neuron projection fields and terminal arbors forming esophageal motor units. Nucleus ambiguus compact formation neurons of the rat were labeled by bilateral intracranial injections of the anterograde tracer dextran biotin. After tracer transport, thoracic and abdominal esophagi were removed and prepared as whole mounts of muscle wall without mucosa or submucosa. Labeled terminal arbors of individual vagal motor neurons (n=78) in the esophageal wall were inventoried, digitized and analyzed morphometrically. The size of individual vagal motor units innervating striated muscle, throughout thoracic and abdominal esophagus, averaged 52 endplates per motor neuron, a value indicative of fine motor control. A majority (77%) of the motor terminal arbors also issued one or more collateral branches that contacted neurons, including nitric oxide synthase-positive neurons, of local myenteric ganglia. Individual motor neuron terminal arbors co-innervated, or supplied endplates in tandem to, both longitudinal and circular muscle fibers in roughly similar proportions (i.e., two endplates to longitudinal for every three endplates to circular fibers). Both the observation that vagal motor unit collaterals project to myenteric ganglia and the fact that individual motor units co-innervate longitudinal and circular muscle layers are consistent with the hypothesis that elements contributing to peristaltic programming inhere, or are "hardwired," in the peripheral architecture of esophageal motor units. © 2013.

Tauopathy induced by low level expression of a human brain-derived tau fragment in mice is rescued by phenylbutyrate.

PubMed

Bondulich, Marie K; Guo, Tong; Meehan, Christopher; Manion, John; Rodriguez Martin, Teresa; Mitchell, Jacqueline C; Hortobagyi, Tibor; Yankova, Natalia; Stygelbout, Virginie; Brion, Jean-Pierre; Noble, Wendy; Hanger, Diane P

2016-08-01

Human neurodegenerative tauopathies exhibit pathological tau aggregates in the brain along with diverse clinical features including cognitive and motor dysfunction. Post-translational modifications including phosphorylation, ubiquitination and truncation, are characteristic features of tau present in the brain in human tauopathy. We have previously reported an N-terminally truncated form of tau in human brain that is associated with the development of tauopathy and is highly phosphorylated. We have generated a new mouse model of tauopathy in which this human brain-derived, 35 kDa tau fragment (Tau35) is expressed in the absence of any mutation and under the control of the human tau promoter. Most existing mouse models of tauopathy overexpress mutant tau at levels that do not occur in human neurodegenerative disease, whereas Tau35 transgene expression is equivalent to less than 10% of that of endogenous mouse tau. Tau35 mice recapitulate key features of human tauopathies, including aggregated and abnormally phosphorylated tau, progressive cognitive and motor deficits, autophagic/lysosomal dysfunction, loss of synaptic protein, and reduced life-span. Importantly, we found that sodium 4-phenylbutyrate (Buphenyl®), a drug used to treat urea cycle disorders and currently in clinical trials for a range of neurodegenerative diseases, reverses the observed abnormalities in tau and autophagy, behavioural deficits, and loss of synapsin 1 in Tau35 mice. Our results show for the first time that, unlike other tau transgenic mouse models, minimal expression of a human disease-associated tau fragment in Tau35 mice causes a profound and progressive tauopathy and cognitive changes, which are rescued by pharmacological intervention using a clinically approved drug. These novel Tau35 mice therefore represent a highly disease-relevant animal model in which to investigate molecular mechanisms and to develop novel treatments for human tauopathies. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain.

Tauopathy induced by low level expression of a human brain-derived tau fragment in mice is rescued by phenylbutyrate

PubMed Central

Bondulich, Marie K.; Guo, Tong; Meehan, Christopher; Manion, John; Rodriguez Martin, Teresa; Mitchell, Jacqueline C.; Hortobagyi, Tibor; Yankova, Natalia; Stygelbout, Virginie; Brion, Jean-Pierre; Noble, Wendy

2016-01-01

Abstract Human neurodegenerative tauopathies exhibit pathological tau aggregates in the brain along with diverse clinical features including cognitive and motor dysfunction. Post-translational modifications including phosphorylation, ubiquitination and truncation, are characteristic features of tau present in the brain in human tauopathy. We have previously reported an N-terminally truncated form of tau in human brain that is associated with the development of tauopathy and is highly phosphorylated. We have generated a new mouse model of tauopathy in which this human brain-derived, 35 kDa tau fragment (Tau35) is expressed in the absence of any mutation and under the control of the human tau promoter. Most existing mouse models of tauopathy overexpress mutant tau at levels that do not occur in human neurodegenerative disease, whereas Tau35 transgene expression is equivalent to less than 10% of that of endogenous mouse tau. Tau35 mice recapitulate key features of human tauopathies, including aggregated and abnormally phosphorylated tau, progressive cognitive and motor deficits, autophagic/lysosomal dysfunction, loss of synaptic protein, and reduced life-span. Importantly, we found that sodium 4-phenylbutyrate (Buphenyl®), a drug used to treat urea cycle disorders and currently in clinical trials for a range of neurodegenerative diseases, reverses the observed abnormalities in tau and autophagy, behavioural deficits, and loss of synapsin 1 in Tau35 mice. Our results show for the first time that, unlike other tau transgenic mouse models, minimal expression of a human disease-associated tau fragment in Tau35 mice causes a profound and progressive tauopathy and cognitive changes, which are rescued by pharmacological intervention using a clinically approved drug. These novel Tau35 mice therefore represent a highly disease-relevant animal model in which to investigate molecular mechanisms and to develop novel treatments for human tauopathies. PMID:27297240

76 FR 88 - Voluntary Termination of Foreign-Trade Subzone 102A, Ford Motor Corporation, Hazelwood, MO

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-03

... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1728] Voluntary Termination of Foreign-Trade Subzone 102A, Ford Motor Corporation, Hazelwood, MO Pursuant to the authority granted in the... the Ford Motor Corporation plant in Hazelwood, Missouri (Board Order 252, 49 FR 19541, 5/8/84...

32 CFR 634.22 - Termination or denial of registration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 4 2010-07-01 2010-07-01 true Termination or denial of registration. 634.22 Section 634.22 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Motor Vehicle Registration § 634.22 Termination or denial of registration...

Progressive Motor Deficit is Mediated by the Denervation of Neuromuscular Junctions and Axonal Degeneration in Transgenic Mice Expressing Mutant (P301S) Tau Protein.

PubMed

Yin, Zhuoran; Valkenburg, Femke; Hornix, Betty E; Mantingh-Otter, Ietje; Zhou, Xingdong; Mari, Muriel; Reggiori, Fulvio; Van Dam, Debby; Eggen, Bart J L; De Deyn, Peter P; Boddeke, Erik

2017-01-01

Tauopathies include a variety of neurodegenerative diseases associated with the pathological aggregation of hyperphosphorylated tau, resulting in progressive cognitive decline and motor impairment. The underlying mechanism for motor deficits related to tauopathy is not yet fully understood. Here, we use a novel transgenic tau mouse line, Tau 58/4, with enhanced neuron-specific expression of P301S mutant tau to investigate the motor abnormalities in association with the peripheral nervous system. Using stationary beam, gait, and rotarod tests, motor deficits were found in Tau 58/4 mice already 3 months after birth, which deteriorated during aging. Hyperphosphorylated tau was detected in the cell bodies and axons of motor neurons. At the age of 9 and 12 months, significant denervation of the neuromuscular junction in the extensor digitorum longus muscle was observed in Tau 58/4 mice, compared to wild-type mice. Muscle hypotrophy was observed in Tau 58/4 mice at 9 and 12 months. Using electron microscopy, we observed ultrastructural changes in the sciatic nerve of 12-month-old Tau 58/4 mice indicative of the loss of large axonal fibers and hypomyelination (assessed by g-ratio). We conclude that the accumulated hyperphosphorylated tau in the axon terminals may induce dying-back axonal degeneration, myelin abnormalities, neuromuscular junction denervation, and muscular atrophy, which may be the mechanisms responsible for the deterioration of the motor function in Tau 58/4 mice. Tau 58/4 mice represent an interesting neuromuscular degeneration model, and the pathological mechanisms might be responsible for motor signs observed in some human tauopathies.

Motor neuron cell-nonautonomous rescue of spinal muscular atrophy phenotypes in mild and severe transgenic mouse models

PubMed Central

Liu, Ying Hsiu; Sahashi, Kentaro; Rigo, Frank; Bennett, C. Frank

2015-01-01

Survival of motor neuron (SMN) deficiency causes spinal muscular atrophy (SMA), but the pathogenesis mechanisms remain elusive. Restoring SMN in motor neurons only partially rescues SMA in mouse models, although it is thought to be therapeutically essential. Here, we address the relative importance of SMN restoration in the central nervous system (CNS) versus peripheral tissues in mouse models using a therapeutic splice-switching antisense oligonucleotide to restore SMN and a complementary decoy oligonucleotide to neutralize its effects in the CNS. Increasing SMN exclusively in peripheral tissues completely rescued necrosis in mild SMA mice and robustly extended survival in severe SMA mice, with significant improvements in vulnerable tissues and motor function. Our data demonstrate a critical role of peripheral pathology in the mortality of SMA mice and indicate that peripheral SMN restoration compensates for its deficiency in the CNS and preserves motor neurons. Thus, SMA is not a cell-autonomous defect of motor neurons in SMA mice. PMID:25583329

Involvement of catecholaminergic neurons in motor innervation of striated muscle in the mouse esophagus.

PubMed

van der Keylen, Piet; Garreis, Fabian; Steigleder, Ruth; Sommer, Daniel; Neuhuber, Winfried L; Wörl, Jürgen

2016-05-01

Enteric co-innervation is a peculiar innervation pattern of striated esophageal musculature. Both anatomical and functional data on enteric co-innervation related to various transmitters have been collected in different species, although its function remains enigmatic. However, it is unclear whether catecholaminergic components are involved in such a co-innervation. Thus, we examined to identify catecholaminergic neuronal elements and clarify their relationship to other innervation components in the esophagus, using immunohistochemistry with antibodies against tyrosine hydroxylase (TH), vesicular acetylcholine transporter (VAChT), choline acetyltransferase (ChAT) and protein gene product 9.5 (PGP 9.5), α-bungarotoxin (α-BT) and PCR with primers for amplification of cDNA encoding TH and dopamine-β-hydroxylase (DBH). TH-positive nerve fibers were abundant throughout the myenteric plexus and localized on about 14% of α-BT-labelled motor endplates differing from VAChT-positive vagal nerve terminals. TH-positive perikarya represented a subpopulation of only about 2.8% of all PGP 9.5-positive myenteric neurons. Analysis of mRNA showed both TH and DBH transcripts in the mouse esophagus. As ChAT-positive neurons in the compact formation of the nucleus ambiguus were negative for TH, the TH-positive nerve varicosities on motor endplates are presumably of enteric origin, although a sympathetic origin cannot be excluded. In the medulla oblongata, the cholinergic ambiguus neurons were densely supplied with TH-positive varicosities. Thus, catecholamines may modulate vagal motor innervation of esophageal-striated muscles not only at the peripheral level via enteric co-innervation but also at the central level via projections to the nucleus ambiguus. As Parkinson's disease, with a loss of central dopaminergic neurons, also affects the enteric nervous system and dysphagia is prevalent in patients with this disease, investigation of intrinsic catecholamines in the esophagus may be worthwhile to understand such a symptom.

Effects of treadmill exercise on behavioral recovery and neural changes in the substantia nigra and striatum of the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-lesioned mouse

PubMed Central

Goldberg, Natalie R.S.; Meshul, Charles K.

2011-01-01

Our goal was to extend our understanding of the neural changes behind motor recovery with treadmill exercise in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned mouse. We determined the extent of dopamine (DA) terminal changes using western immunoblotting [striatal dopamine transporter (DAT) and tyrosine hydroxylase (TH)] and alterations in the mean number of DA cells/section by immunohistochemistry and Nissl staining [TH-labeled cells and thionin-stained cells in the substantia nigra pars compacta (SN-PC)]. We measured recovery of gait performance and amount of spontaneous physical activity using the parallel rod activity chamber (PRAC). We hypothesized that the decrease in TH-labeled neurons in the SN-PC due to MPTP will be partially reversed by treadmill exercise, leading to recovery of motor behavior as measured by the PRAC. Following MPTP or vehicle administration, mice ran on the treadmill for 1 hour per day at 18 cm/s, 5 days per week. Results showed that treadmill exercise improves gait performance and increases physical activity while promoting increased protein expression of striatal DAT and TH. Exercise was effective for all mice, however effects of early treadmill-based intervention appear to have an additional and unique benefit in mice who received MPTP. We are the first to show that, even following a nearly 50% decrease in the mean number of TH-labeled neurons/section in the SN-PC following MPTP, treadmill exercise leads to an increase of neurons in the SN-PC and improved motor behavior. PMID:21315689

Mouse Noxa uses only the C-terminal BH3-domain to inactivate Mcl-1.

PubMed

Weber, Arnim; Ausländer, David; Häcker, Georg

2013-09-01

Noxa is a member of the pro-apoptotic BH3-only group of Bcl-2 proteins that is known to bind specifically to anti-apoptotic Mcl-1 and A1, antagonizing their function. Mcl-1 has been reported to have a short half-life, and Noxa up-regulation accelerates Mcl-1 degradation by the proteasome. Unlike human Noxa, mouse Noxa has two BH3-domains, which both have affinity for Mcl-1. We here investigate two aspects of the molecular function of Noxa, namely the requirements for the two BH3-domains in mouse Noxa and the role of Noxa in Mcl-1-degradation. We found that only the C-terminal BH3-domain of mouse Noxa is active in neutralizing Mcl-1. This was the result of the targeting of Noxa to the outer mitochondrial membrane through its C-terminal alpha-helix, which allowed Mcl-1-neutralization only when the BH3-domain was immediately N-terminal of the membrane anchor. However, the N-terminal BH3-domain enhanced interaction with Mcl-1 and A1. The Noxa-dependent degradation of Mcl-1 was independent of the kinase GSK3 and the deubiquitinase Usp9x in mouse embryonic fibroblasts. These data show that Noxa is targeted to the mitochondrial membrane where it neutralises Mcl-1 via its C-terminal BH3-domain and suggest that Noxa is co-degraded with Noxa, in a way independent of ubiquitin-modifying enzymes described for Mcl-1.

C1q-targeted inhibition of the classical complement pathway prevents injury in a novel mouse model of acute motor axonal neuropathy.

PubMed

McGonigal, Rhona; Cunningham, Madeleine E; Yao, Denggao; Barrie, Jennifer A; Sankaranarayanan, Sethu; Fewou, Simon N; Furukawa, Koichi; Yednock, Ted A; Willison, Hugh J

2016-03-02

Guillain-Barré syndrome (GBS) is an autoimmune disease that results in acute paralysis through inflammatory attack on peripheral nerves, and currently has limited, non-specific treatment options. The pathogenesis of the acute motor axonal neuropathy (AMAN) variant is mediated by complement-fixing anti-ganglioside antibodies that directly bind and injure the axon at sites of vulnerability such as nodes of Ranvier and nerve terminals. Consequently, the complement cascade is an attractive target to reduce disease severity. Recently, C5 complement component inhibitors that block the formation of the membrane attack complex and subsequent downstream injury have been shown to be efficacious in an in vivo anti-GQ1b antibody-mediated mouse model of the GBS variant Miller Fisher syndrome (MFS). However, since gangliosides are widely expressed in neurons and glial cells, injury in this model was not targeted exclusively to the axon and there are currently no pure mouse models for AMAN. Additionally, C5 inhibition does not prevent the production of early complement fragments such as C3a and C3b that can be deleterious via their known role in immune cell and macrophage recruitment to sites of neuronal damage. In this study, we first developed a new in vivo transgenic mouse model of AMAN using mice that express complex gangliosides exclusively in neurons, thereby enabling specific targeting of axons with anti-ganglioside antibodies. Secondly, we have evaluated the efficacy of a novel anti-C1q antibody (M1) that blocks initiation of the classical complement cascade, in both the newly developed anti-GM1 antibody-mediated AMAN model and our established MFS model in vivo. Anti-C1q monoclonal antibody treatment attenuated complement cascade activation and deposition, reduced immune cell recruitment and axonal injury, in both mouse models of GBS, along with improvement in respiratory function. These results demonstrate that neutralising C1q function attenuates injury with a consequent neuroprotective effect in acute GBS models and promises to be a useful new target for human therapy.

The final stage of cholinergic differentiation occurs below inner hair cells during development of the rodent cochlea.

PubMed

Bergeron, Adam L; Schrader, Angela; Yang, Dan; Osman, Abdullah A; Simmons, Dwayne D

2005-12-01

To gain further insights into the cholinergic differentiation of presynaptic efferent terminals in the inner ear, we investigated the expression of the high-affinity choline transporter (ChT1) in comparison to other presynaptic and cholinergic markers. In the adult mammalian cochlea, cholinergic axons from medial olivocochlear (OC) neurons form axosomatic synapses with outer hair cells (OHCs), whereas axons from lateral OC neurons form axodendritic synapses on afferent fibers below inner hair cells (IHCs). Mouse brain and cochlea homogenates reveal at least two ChT1 isoforms: a nonglycosylated approximately 73 kDa protein and a glycosylated approximately 45 kDa protein. In mouse brain, ChT1 is preferentially expressed by neurons in periolivary regions of the superior olive consistent with the location of medial OC neurons. In the adult mouse cochlea, ChT1-positive terminals are located almost exclusively below OHCs consistent with a medial OC innervation. Between postnatal day 2 (P2) and P4, ChT1-positive terminals are below IHCs and occur after the expression of growth-associated protein 43, synapsin, and the vesicular acetylcholine transporter. By P15, ChT1-positive terminals are mostly on OHCs. Accounting for differences in gestational age, the developmental expression of ChT1 in the rat cochlea is similar to the mouse. However, in older rats ChT1-positive terminals are below IHCs and OHCs. In both rat and mouse, our observations indicate that the onset of ChT1 expression occurs after efferent terminals are below IHCs and express other presynaptic and cholinergic markers. In the mouse, but not in the rat, ChT1 may preferentially identify medial OC neurons.

Method and apparatus for monitoring the rotating frequency of de-energized induction motors

DOEpatents

Mikesell, H.E.; Lucy, E.

1998-02-03

The rotational speed of a coasting induction motor is measured by sensing e residual electrical voltages at the power terminals of the motor, thus eliminating the need for conventional tachometer equipment, additional mechanical components or modifications to the induction motor itself. The power terminal voltage signal is detected and transformed into a DC voltage proportional to the frequency of the signal. This DC voltage can be input to the control system of a variable frequency motor controller to regulate the output characteristics thereof relative to the speed of the coasting motor. 6 figs.

Method and apparatus for monitoring the rotating frequency of de-energized induction motors

DOEpatents

Mikesell, Harvey E.; Lucy, Eric

1998-01-01

The rotational speed of a coasting induction motor is measured by sensing e residual electrical voltages at the power terminals of the motor, thus eliminating the need for conventional tachometer equipment, additional mechanical components or modifications to the induction motor itself. The power terminal voltage signal is detected and transformed into a DC voltage proportional to the frequency of the signal. This DC voltage can be input to the control system of a variable frequency motor controller to regulate the output characteristics thereof relative to the speed of the coasting motor.

Peroxisome proliferator activator receptor gamma coactivator-1alpha (PGC-1α) improves motor performance and survival in a mouse model of amyotrophic lateral sclerosis

PubMed Central

2011-01-01

Background Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease that affects spinal cord and cortical motor neurons. An increasing amount of evidence suggests that mitochondrial dysfunction contributes to motor neuron death in ALS. Peroxisome proliferator-activated receptor gamma co-activator-1α (PGC-1α) is a principal regulator of mitochondrial biogenesis and oxidative metabolism. Results In this study, we examined whether PGC-1α plays a protective role in ALS by using a double transgenic mouse model where PGC-1α is over-expressed in an SOD1 transgenic mouse (TgSOD1-G93A/PGC-1α). Our results indicate that PGC-1α significantly improves motor function and survival of SOD1-G93A mice. The behavioral improvements were accompanied by reduced blood glucose level and by protection of motor neuron loss, restoration of mitochondrial electron transport chain activities and inhibition of stress signaling in the spinal cord. Conclusion Our results demonstrate that PGC-1α plays a beneficial role in a mouse model of ALS, suggesting that PGC-1α may be a potential therapeutic target for ALS therapy. PMID:21771318

Co-localization of polar replication fork barriers and rRNA transcription terminators in mouse rDNA.

PubMed

López-estraño, C; Schvartzman, J B; Krimer, D B; Hernández, P

1998-03-27

We investigated the replication of the region where transcription terminates in mouse rDNA. It contains a replication fork barrier (RFB) that behaves in a polar manner, arresting only replication forks moving in the direction opposite to transcription. This RFB consists of several closely spaced fork arrest sites that co-localize with the transcription terminator elements, known as Sal boxes. Sal boxes are the target for mTTF-I (murine transcription termination factor I). These results suggest that both termination of rRNA transcription and replication fork arrest may share cis-acting as well as trans-acting factors. Copyright 1998 Academic Press Limited.

Mouse Driven Window Graphics for Network Teaching.

ERIC Educational Resources Information Center

Makinson, G. J.; And Others

Computer enhanced teaching of computational mathematics on a network system driving graphics terminals is being redeveloped for a mouse-driven, high resolution, windowed environment of a UNIX work station. Preservation of the features of networked access by heterogeneous terminals is provided by the use of the X Window environment. A dmonstrator…

The open reading frames in the 3' long terminal repeats of several mouse mammary tumor virus integrants encode V beta 3-specific superantigens

PubMed Central

1992-01-01

Mice expressing the minor lymphocyte stimulation antigens, Mls-1a, -2a, or -3a, singly on the B10.BR background have been generated. Mls phenotypes correlate with the integration of mouse mammary tumor viruses (MTV) in the mouse genome. The open reading frames within the 3' long terminal repeats of the integrated MTVs 1, 3, 6, and 13 encode V beta 3-specific superantigens. Sequence data for these viral superantigens is presented, indicating that it is the COOH-terminal portion of the viral superantigen that interacts with the T cell receptor V beta element. PMID:1309854

P-type voltage-dependent calcium channel mediates presynaptic calcium influx and transmitter release in mammalian synapses.

PubMed Central

Uchitel, O D; Protti, D A; Sanchez, V; Cherksey, B D; Sugimori, M; Llinás, R

1992-01-01

We have studied the effect of the purified toxin from the funnel-web spider venom (FTX) and its synthetic analog (sFTX) on transmitter release and presynaptic currents at the mouse neuromuscular junction. FTX specifically blocks the omega-conotoxin- and dihydropyridine-insensitive P-type voltage-dependent Ca2+ channel (VDCC) in cerebellar Purkinje cells. Mammalian neuromuscular transmission, which is insensitive to N- or L-type Ca2+ channel blockers, was effectively abolished by FTX and sFTX. These substances blocked the muscle contraction and the neurotransmitter release evoked by nerve stimulation. Moreover, presynaptic Ca2+ currents recorded extracellularly from the interior of the perineural sheaths of nerves innervating the mouse levator auris muscle were specifically blocked by both natural toxin and synthetic analogue. In a parallel set of experiments, K(+)-induced Ca45 uptake by brain synaptosomes was also shown to be blocked or greatly diminished by FTX and sFTX. These results indicate that the predominant VDCC in the motor nerve terminals, and possibly in a significant percentage of brain synapses, is the P-type channel. Images PMID:1348859

P-type voltage-dependent calcium channel mediates presynaptic calcium influx and transmitter release in mammalian synapses.

PubMed

Uchitel, O D; Protti, D A; Sanchez, V; Cherksey, B D; Sugimori, M; Llinás, R

1992-04-15

We have studied the effect of the purified toxin from the funnel-web spider venom (FTX) and its synthetic analog (sFTX) on transmitter release and presynaptic currents at the mouse neuromuscular junction. FTX specifically blocks the omega-conotoxin- and dihydropyridine-insensitive P-type voltage-dependent Ca2+ channel (VDCC) in cerebellar Purkinje cells. Mammalian neuromuscular transmission, which is insensitive to N- or L-type Ca2+ channel blockers, was effectively abolished by FTX and sFTX. These substances blocked the muscle contraction and the neurotransmitter release evoked by nerve stimulation. Moreover, presynaptic Ca2+ currents recorded extracellularly from the interior of the perineural sheaths of nerves innervating the mouse levator auris muscle were specifically blocked by both natural toxin and synthetic analogue. In a parallel set of experiments, K(+)-induced Ca45 uptake by brain synaptosomes was also shown to be blocked or greatly diminished by FTX and sFTX. These results indicate that the predominant VDCC in the motor nerve terminals, and possibly in a significant percentage of brain synapses, is the P-type channel.

A Map of Anticipatory Activity in Mouse Motor Cortex.

PubMed

Chen, Tsai-Wen; Li, Nuo; Daie, Kayvon; Svoboda, Karel

2017-05-17

Activity in the mouse anterior lateral motor cortex (ALM) instructs directional movements, often seconds before movement initiation. It is unknown whether this preparatory activity is localized to ALM or widely distributed within motor cortex. Here we imaged activity across motor cortex while mice performed a whisker-based object localization task with a delayed, directional licking response. During tactile sensation and the delay epoch, object location was represented in motor cortex areas that are medial and posterior relative to ALM, including vibrissal motor cortex. Preparatory activity appeared first in deep layers of ALM, seconds before the behavioral response, and remained localized to ALM until the behavioral response. Later, widely distributed neurons represented the outcome of the trial. Cortical area was more predictive of neuronal selectivity than laminar location or axonal projection target. Motor cortex therefore represents sensory, motor, and outcome information in a spatially organized manner. Copyright © 2017 Elsevier Inc. All rights reserved.

A Battery of Motor Tests in a Neonatal Mouse Model of Cerebral Palsy.

PubMed

Feather-Schussler, Danielle N; Ferguson, Tanya S

2016-11-03

As the sheer number of transgenic mice strains grow and rodent models of pediatric disease increase, there is an expanding need for a comprehensive, standardized battery of neonatal mouse motor tests. These tests can validate injury or disease models, determine treatment efficacy and/or assess motor behaviors in new transgenic strains. This paper presents a series of neonatal motor tests to evaluate general motor function, including ambulation, hindlimb foot angle, surface righting, negative geotaxis, front- and hindlimb suspension, grasping reflex, four limb grip strength and cliff aversion. Mice between the ages of post-natal day 2 to 14 can be used. In addition, these tests can be used for a wide range of neurological and neuromuscular pathologies, including cerebral palsy, hypoxic-ischemic encephalopathy, traumatic brain injury, spinal cord injury, neurodegenerative diseases, and neuromuscular disorders. These tests can also be used to determine the effects of pharmacological agents, as well as other types of therapeutic interventions. In this paper, motor deficits were evaluated in a novel neonatal mouse model of cerebral palsy that combines hypoxia, ischemia and inflammation. Forty-eight hours after injury, five tests out of the nine showed significant motor deficits: ambulation, hindlimb angle, hindlimb suspension, four limb grip strength, and grasping reflex. These tests revealed weakness in the hindlimbs, as well as fine motor skills such as grasping, which are similar to the motor deficits seen in human cerebral palsy patients.

Changes in Cerebral Hemodynamics during Complex Motor Learning by Character Entry into Touch-Screen Terminals.

PubMed

Sagari, Akira; Iso, Naoki; Moriuchi, Takefumi; Ogahara, Kakuya; Kitajima, Eiji; Tanaka, Koji; Tabira, Takayuki; Higashi, Toshio

2015-01-01

Studies of cerebral hemodynamics during motor learning have mostly focused on neurorehabilitation interventions and their effectiveness. However, only a few imaging studies of motor learning and the underlying complex cognitive processes have been performed. We measured cerebral hemodynamics using near-infrared spectroscopy (NIRS) in relation to acquisition patterns of motor skills in healthy subjects using character entry into a touch-screen terminal. Twenty healthy, right-handed subjects who had no previous experience with character entry using a touch-screen terminal participated in this study. They were asked to enter the characters of a randomly formed Japanese syllabary into the touch-screen terminal. All subjects performed the task with their right thumb for 15 s alternating with 25 s of rest for 30 repetitions. Performance was calculated by subtracting the number of incorrect answers from the number of correct answers, and gains in motor skills were evaluated according to the changes in performance across cycles. Behavioral and oxygenated hemoglobin concentration changes across task cycles were analyzed using Spearman's rank correlations. Performance correlated positively with task cycle, thus confirming motor learning. Hemodynamic activation over the left sensorimotor cortex (SMC) showed a positive correlation with task cycle, whereas activations over the right prefrontal cortex (PFC) and supplementary motor area (SMA) showed negative correlations. We suggest that increases in finger momentum with motor learning are reflected in the activity of the left SMC. We further speculate that the right PFC and SMA were activated during the early phases of motor learning, and that this activity was attenuated with learning progress.

eGFP expression under the Uchl1 promoter labels corticospinal motor neurons and a subpopulation of degeneration resistant spinal motor neurons in ALS mouse models

NASA Astrophysics Data System (ADS)

Yasvoina, Marina V.

Current understanding of basic cellular and molecular mechanisms for motor neuron vulnerability during motor neuron disease initiation and progression is incomplete. The complex cytoarchitecture and cellular heterogeneity of the cortex and spinal cord greatly impedes our ability to visualize, isolate, and study specific neuron populations in both healthy and diseased states. We generated a novel reporter line, the Uchl1-eGFP mouse, in which cortical and spinal components of motor neuron circuitry are genetically labeled with eGFP under the Uchl1 promoter. A series of cellular and anatomical analyses combined with retrograde labeling, molecular marker expression, and electrophysiology were employed to determine identity of eGFP expressing cells in the motor cortex and the spinal cord of novel Uchl1-eGFP reporter mice. We conclude that eGFP is expressed in corticospinal motor neurons (CSMN) in the motor cortex and a subset of S-type alpha and gamma spinal motor neurons (SMN) in the spinal cord. hSOD1G93A and Alsin-/- mice, mouse models for amyotrophic lateral sclerosis (ALS), were bred to Uchl1-eGFP reporter mouse line to investigate the pathophysiology and underlying mechanisms of CSMN degeneration in vivo. Evidence suggests early and progressive degeneration of CSMN and SMN in the hSOD1G93A transgenic mice. We show an early increase of autophagosome formation in the apical dendrites of vulnerable CSMN in hSOD1G93A-UeGFP mice, which is localized to the apical dendrites. In addition, labeling S-type alpha and gamma SMN in the hSOD1G93A-UeGFP mice provide a unique opportunity to study basis of their resistance to degeneration. Mice lacking alsin show moderate clinical phenotype and mild CSMN axon degeneration in the spinal cord, which suggests vulnerability of CSMN. Therefore, we investigated the CSMN cellular and axon defects in aged Alsin-/- mice bred to Uchl1-eGFP reporter mouse line. We show that while CSMN are preserved and lack signs of degeneration, CSMN axons are vulnerable and show significant loss.

46 CFR 525.2 - Terminal schedules.

Code of Federal Regulations, 2011 CFR

2011-10-01

... scrap, new assembled motor vehicles, waste paper and paper waste in terminal schedules. (2) Marine... MARITIME COMMISSION REGULATIONS AFFECTING OCEAN SHIPPING IN FOREIGN COMMERCE MARINE TERMINAL OPERATOR SCHEDULES § 525.2 Terminal schedules. (a) Marine terminal operator schedules. A marine terminal operator, at...

46 CFR 525.2 - Terminal schedules.

Code of Federal Regulations, 2010 CFR

2010-10-01

... scrap, new assembled motor vehicles, waste paper and paper waste in terminal schedules. (2) Marine... MARITIME COMMISSION REGULATIONS AFFECTING OCEAN SHIPPING IN FOREIGN COMMERCE MARINE TERMINAL OPERATOR SCHEDULES § 525.2 Terminal schedules. (a) Marine terminal operator schedules. A marine terminal operator, at...

Mechanisms of DNA Packaging by Large Double-Stranded DNA Viruses

PubMed Central

Rao, Venigalla B.; Feiss, Michael

2016-01-01

Translocation of viral double-stranded DNA (dsDNA) into the icosahedral prohead shell is catalyzed by TerL, a motor protein that has ATPase, endonuclease, and translocase activities. TerL, following endonucleolytic cleavage of immature viral DNA concatemer recognized by TerS, assembles into a pentameric ring motor on the prohead’s portal vertex and uses ATP hydrolysis energy for DNA translocation. TerL’s N-terminal ATPase is connected by a hinge to the C-terminal endonuclease. Inchworm models propose that modest domain motions accompanying ATP hydrolysis are amplified, through changes in electrostatic interactions, into larger movements of the C-terminal domain bound to DNA. In phage φ29, four of the five TerL subunits sequentially hydrolyze ATP, each powering translocation of 2.5 bp. After one viral genome is encapsidated, the internal pressure signals termination of packaging and ejection of the motor. Current focus is on the structures of packaging complexes and the dynamics of TerL during DNA packaging, endonuclease regulation, and motor mechanics. PMID:26958920

System and method for determining stator winding resistance in an AC motor using motor drives

DOEpatents

Lu, Bin; Habetler, Thomas G; Zhang, Pinjia

2013-02-26

A system and method for determining the stator winding resistance of AC motors is provided. The system includes an AC motor drive having an input connectable to an AC source and an output connectable to an input terminal of an AC motor, a pulse width modulation (PWM) converter having switches therein to control current flow and terminal voltages in the AC motor, and a control system connected to the PWM converter. The control system generates a command signal to cause the PWM converter to control an output of the AC motor drive corresponding to an input to the AC motor, selectively generates a modified command signal to cause the PWM converter to inject a DC signal into the output of the AC motor drive, and determines a stator winding resistance of the AC motor based on the DC signal of at least one of the voltage and current.

Adult mouse motor units develop almost all of their force in the subprimary range: a new all-or-none strategy for force recruitment?

PubMed

Manuel, Marin; Heckman, C J

2011-10-19

Classical studies of the mammalian neuromuscular system have shown an impressive adaptation match between the intrinsic properties of motoneurons and the contractile properties of their motor units. In these studies, the rate at which motoneurons start to fire repetitively corresponds to the rate at which individual twitches start to sum, and the firing rate increases linearly with the amount of excitation ("primary range") up to the point where the motor unit develops its maximal force. This allows for the gradation of the force produced by a motor unit by rate modulation. In adult mouse motoneurons, however, we recently described a regime of firing ("subprimary range") that appears at lower excitation than what is required for the primary range, a finding that might challenge the classical conception. To investigate the force production of mouse motor units, we simultaneously recorded, for the first time, the motoneuron discharge elicited by intracellular ramps of current and the force developed by its motor unit. We showed that the motor unit developed nearly its maximal force during the subprimary range. This was found to be the case regardless of the input resistance of the motoneuron, the contraction speed, or the tetanic force of the motor unit. Our work suggests that force modulation in small mammals mainly relies on the number of motor units that are recruited rather than on rate modulation of individual motor units.

Dynamic Re-wiring of Neural Circuits in the Motor Cortex in Mouse Models of Parkinson's Disease

PubMed Central

Lalchandani, Rupa R.; Cui, Yuting; Shu, Yu; Xu, Tonghui; Ding, Jun B.

2015-01-01

SUMMARY Dynamic adaptations in synaptic plasticity are critical for learning new motor skills and maintaining memory throughout life, which rapidly decline with Parkinson's disease (PD). Plasticity in the motor cortex is important for acquisition and maintenance of novel motor skills, but how the loss of dopamine in PD leads to disrupted structural and functional plasticity in the motor cortex is not well understood. Here, we utilized mouse models of PD and 2-photon imaging to show that dopamine depletion resulted in structural changes in the motor cortex. We further discovered that dopamine D1 and D2 receptor signaling were linked to selectively and distinctly regulating these aberrant changes in structural and functional plasticity. Our findings suggest that both D1 and D2 receptor signaling regulate motor cortex plasticity, and loss of dopamine results in atypical synaptic adaptations that may contribute to the impairment of motor performance and motor memory observed in PD. PMID:26237365

Angiogenesis within the developing mouse neural tube is dependent on sonic hedgehog signaling: possible roles of motor neurons.

PubMed

Nagase, Takashi; Nagase, Miki; Yoshimura, Kotaro; Fujita, Toshiro; Koshima, Isao

2005-06-01

Embryonic morphogenesis of vascular and nervous systems is tightly coordinated, and recent studies revealed that some neurogenetic factors such as Sonic hedgehog (Shh) also exhibit angiogenetic potential. Vascularization within the developing mouse neural tube depends on vessel sprouting from the surrounding vascular plexus. Previous studies implicated possible roles of VEGF/Flk-1 and Angiopoietin-1(Ang-1)/Tie-2 signaling as candidate molecules functioning in this process. Examining gene expressions of these factors at embryonic day (E) 9.5 and 10.5, we unexpectedly found that both VEGF and Ang-1 were expressed in the motor neurons in the ventral neural tube. The motor neurons were indeed located in the close vicinity of the infiltrating vessels, suggesting involvement of motor neurons in the sprouting. To substantiate this possibility, we inhibited induction of the motor neurons in the cultured mouse embryos by cyclopamine, a Shh signaling blocker. The vessel sprouting was dramatically impaired by inhibition of Shh signaling, together with nearly complete loss of the motor neurons. Expression of Ang-1, but not VEGF, within the neural tube was remarkably reduced in the cyclopamine treated embryos. These results suggest that the neural tube angiogenesis is dependent on Shh signaling, and mediated, at least in part, by the Ang-1 positive motor neurons.

Analysis of motor dysfunction in Down Syndrome reveals motor neuron degeneration

PubMed Central

Lana-Elola, Eva; Gibbins, Dorota; La Russa, Federica; Wiseman, Frances; Williamson, Matthew; Saccon, Rachele; Olerinyova, Anna; Mahmood, Radma; Nye, Emma; Cater, Heather; Yu, Y. Eugene; Bennett, David L. H.; Greensmith, Linda; Fisher, Elizabeth M. C.

2018-01-01

Down Syndrome (DS) is caused by trisomy of chromosome 21 (Hsa21) and results in a spectrum of phenotypes including learning and memory deficits, and motor dysfunction. It has been hypothesized that an additional copy of a few Hsa21 dosage-sensitive genes causes these phenotypes, but this has been challenged by observations that aneuploidy can cause phenotypes by the mass action of large numbers of genes, with undetectable contributions from individual sequences. The motor abnormalities in DS are relatively understudied—the identity of causative dosage-sensitive genes and the mechanism underpinning the phenotypes are unknown. Using a panel of mouse strains with duplications of regions of mouse chromosomes orthologous to Hsa21 we show that increased dosage of small numbers of genes causes locomotor dysfunction and, moreover, that the Dyrk1a gene is required in three copies to cause the phenotype. Furthermore, we show for the first time a new DS phenotype: loss of motor neurons both in mouse models and, importantly, in humans with DS, that may contribute to locomotor dysfunction. PMID:29746474

TRPV2 ion channels expressed in inhibitory motor neurons of gastric myenteric plexus contribute to gastric adaptive relaxation and gastric emptying in mice.

PubMed

Mihara, Hiroshi; Suzuki, Nobuhiro; Yamawaki, Hidemoto; Tominaga, Makoto; Sugiyama, Toshiro

2013-02-01

Gastric adaptive relaxation (GAR) is impaired in ~40% of functional dyspepsia (FD) patients, and nitric oxide (NO) released from inhibitory motor neurons plays an important role in this relaxation. Although the underlying molecular mechanism of GAR is poorly understood, transient receptor potential channel vanilloid 2 (TRPV2) mechano- and chemoreceptors are expressed in mouse intestinal inhibitory motor neurons and are involved in intestinal relaxation. The aim of this study was to evaluate the distribution of TRPV2 in inhibitory motor neurons throughout the mouse gastrointestinal tract and the contribution of TRPV2 to GAR. RT-PCR and immunohistochemical analyses were used to detect TRPV2 mRNA and protein, respectively. Intragastric pressure was determined with an isolated mouse stomach. Gastric emptying (GE) in vivo was determined using a test meal. TRPV2 mRNA was detected throughout the mouse gastrointestinal tract, and TRPV2 immunoreactivity was detected in 84.3% of neuronal nitric oxide synthase-expressing myenteric neurons in the stomach. GAR, which was expressed as the rate of decline of intragastric pressure in response to volume stimuli, was significantly enhanced by the TRPV2 activator probenecid, and the enhancement was inhibited by the TRPV2 inhibitor tranilast. GE was significantly accelerated by TRPV2 agonist applications, and the probenecid-induced enhancement was significantly inhibited by tranilast coapplication. Mechanosensitive TRPV2 was expressed in inhibitory motor neurons in the mouse stomach and contributed to GAR and GE. TRPV2 may be a promising target for FD patients with impaired GAR.

Selective disruption of acetylcholine synthesis in subsets of motor neurons: a new model of late-onset motor neuron disease.

PubMed

Lecomte, Marie-José; Bertolus, Chloé; Santamaria, Julie; Bauchet, Anne-Laure; Herbin, Marc; Saurini, Françoise; Misawa, Hidemi; Maisonobe, Thierry; Pradat, Pierre-François; Nosten-Bertrand, Marika; Mallet, Jacques; Berrard, Sylvie

2014-05-01

Motor neuron diseases are characterized by the selective chronic dysfunction of a subset of motor neurons and the subsequent impairment of neuromuscular function. To reproduce in the mouse these hallmarks of diseases affecting motor neurons, we generated a mouse line in which ~40% of motor neurons in the spinal cord and the brainstem become unable to sustain neuromuscular transmission. These mice were obtained by conditional knockout of the gene encoding choline acetyltransferase (ChAT), the biosynthetic enzyme for acetylcholine. The mutant mice are viable and spontaneously display abnormal phenotypes that worsen with age including hunched back, reduced lifespan, weight loss, as well as striking deficits in muscle strength and motor function. This slowly progressive neuromuscular dysfunction is accompanied by muscle fiber histopathological features characteristic of neurogenic diseases. Unexpectedly, most changes appeared with a 6-month delay relative to the onset of reduction in ChAT levels, suggesting that compensatory mechanisms preserve muscular function for several months and then are overwhelmed. Deterioration of mouse phenotype after ChAT gene disruption is a specific aging process reminiscent of human pathological situations, particularly among survivors of paralytic poliomyelitis. These mutant mice may represent an invaluable tool to determine the sequence of events that follow the loss of function of a motor neuron subset as the disease progresses, and to evaluate therapeutic strategies. They also offer the opportunity to explore fundamental issues of motor neuron biology. Copyright © 2014 Elsevier Inc. All rights reserved.

Identification and biochemical analysis of Slac2-c/MyRIP as a Rab27A-, myosin Va/VIIa-, and actin-binding protein.

PubMed

Kuroda, Taruho S; Fukuda, Mitsunori

2005-01-01

Slac2-c/MyRIP is a specific Rab27A-binding protein that contains an N-terminal synaptotagmin-like protein (Slp) homology domain (SHD, a newly identified GTP-Rab27A-binding motif), but in contrast to the Slp family proteins, it lacks C-terminal tandem C2 domains. In vitro Slac2-c simultaneously directly interacts with both Rab27A and an actin-based motor protein, myosin Va, via its N-terminal SHD and middle region, respectively, consistent with the fact that the overall structure of Slac2-c is similar to that of Slac2-a/melanophilin, a linker protein between Rab27A and myosin Va in the melanosome transport in melanocytes. Unlike Slac2-a, however, the middle region of Slac2-c interacts with two types of myosins, myosin Va and myosin VIIa. In addition, the most C-terminal part of both Slac2-a and Slac2-c functions as an actin-binding domain: it directly interacts with globular and fibrous actin in vitro, and the actin-binding domain of Slac2-a and Slac2-c colocalizes with actin filaments when it is expressed in living cells (i.e., PC12 cells and mouse melanocytes). In this chapter we describe the methods that have been used to analyze the protein-protein interactions of Slac2-c, specifically with Rab27A, myosin Va/VIIa, and actin.

Mouse Na+/K+-ATPase β1-subunit has a K+-dependent cell adhesion activity for β-GlcNAc-terminating glycans

PubMed Central

Kitamura, Noriaki; Ikekita, Masahiko; Sato, Takeshi; Akimoto, Yoshihiro; Hatanaka, Yasumaru; Kawakami, Hayato; Inomata, Mitsushi; Furukawa, Kiyoshi

2005-01-01

A 48-kDa β-N-acetylglucosamine (GlcNAc)-binding protein was isolated from mouse brain by GlcNAc-agarose column chromatography. The N-terminal amino acid residues showed the protein to be a mouse Na+/K+-ATPase β1-subunit. When the recombinant FLAG-β1-subunit expressed in Sf-9 cells was applied to a GlcNAc-agarose column, only the glycosylated 38- and 40-kDa proteins bound to the column. In the absence of KCl, little of the proteins bound to a GlcNAc-agarose column, but the 38- and 40-kDa proteins bound in the presence of KCl at concentrations above 1 mM. Immunohistochemical study showed that the β1-subunit and GlcNAc-terminating oligosaccharides are at the cell contact sites. Inclusion of anti-β1-subunit antibody or chitobiose in cell aggregation assays using mouse neural cells resulted in inhibition of cell aggregation. These results indicate that the Na+/K+-ATPase β1-subunit is a potassium-dependent lectin that binds to GlcNAc-terminating oligosaccharides: it may be involved in neural cell interactions. PMID:15705719

Mouse vocal communication system: are ultrasounds learned or innate?

PubMed Central

Arriaga, Gustavo; Jarvis, Erich D.

2013-01-01

Mouse ultrasonic vocalizations (USVs) are often used as behavioral readouts of internal states, to measure effects of social and pharmacological manipulations, and for behavioral phenotyping of mouse models for neuropsychiatric and neurodegenerative disorders. However, little is known about the neurobiological mechanisms of rodent USV production. Here we discuss the available data to assess whether male mouse song behavior and the supporting brain circuits resemble those of known vocal non-learning or vocal learning species. Recent neurobiology studies have demonstrated that the mouse USV brain system includes motor cortex and striatal regions, and that the vocal motor cortex sends a direct sparse projection to the brainstem vocal motor nucleus ambiguous, a projection thought be unique to humans among mammals. Recent behavioral studies have reported opposing conclusions on mouse vocal plasticity, including vocal ontogeny changes in USVs over early development that might not be explained by innate maturation processes, evidence for and against a role for auditory feedback in developing and maintaining normal mouse USVs, and evidence for and against limited vocal imitation of song pitch. To reconcile these findings, we suggest that the trait of vocal learning may not be dichotomous but encompass a broad set of behavioral and neural traits we call the continuum hypothesis, and that mice possess some of the traits associated with a capacity for limited vocal learning. PMID:23295209

Recycling of Kinesin-1 Motors by Diffusion after Transport

PubMed Central

Blasius, T. Lynne; Reed, Nathan; Slepchenko, Boris M.; Verhey, Kristen J.

2013-01-01

Kinesin motors drive the long-distance anterograde transport of cellular components along microtubule tracks. Kinesin-dependent transport plays a critical role in neurogenesis and neuronal function due to the large distance separating the soma and nerve terminal. The fate of kinesin motors after delivery of their cargoes is unknown but has been postulated to involve degradation at the nerve terminal, recycling via retrograde motors, and/or recycling via diffusion. We set out to test these models concerning the fate of kinesin-1 motors after completion of transport in neuronal cells. We find that kinesin-1 motors are neither degraded nor returned by retrograde motors. By combining mathematical modeling and experimental analysis, we propose a model in which the distribution and recycling of kinesin-1 motors fits a “loose bucket brigade” where individual motors alter between periods of active transport and free diffusion within neuronal processes. These results suggest that individual kinesin-1 motors are utilized for multiple rounds of transport. PMID:24098765

Bidirectional motility of the fission yeast kinesin-5, Cut7

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edamatsu, Masaki, E-mail: cedam@mail.ecc.u-tokyo.ac.jp

Highlights: • Motile properties of Cut7 (fission yeast kinesin-5) were studied for the first time. • Half-length Cut7 moved toward plus-end direction of microtubule. • Full-length Cut7 moved toward minus-end direction of microtubule. • N- and C-terminal microtubule binding sites did not switch the motile direction. - Abstract: Kinesin-5 is a homotetrameric motor with its motor domain at the N-terminus. Kinesin-5 crosslinks microtubules and functions in separating spindle poles during mitosis. In this study, the motile properties of Cut7, fission yeast kinesin-5, were examined for the first time. In in vitro motility assays, full-length Cut7 moved toward minus-end of microtubules,more » but the N-terminal half of Cut7 moved toward the opposite direction. Furthermore, additional truncated constructs lacking the N-terminal or C-terminal regions, but still contained the motor domain, did not switch the motile direction. These indicated that Cut7 was a bidirectional motor, and microtubule binding regions at the N-terminus and C-terminus were not involved in its directionality.« less

Amorphous silicon cell array powered solar tracking apparatus

DOEpatents

Hanak, Joseph J.

1985-01-01

An array of an even number of amorphous silicon solar cells are serially connected between first and second terminals of opposite polarity. The terminals are connected to one input terminal of a DC motor whose other input terminal is connected to the mid-cell of the serial array. Vane elements are adjacent the end cells to selectively shadow one or the other of the end cells when the array is oriented from a desired attitude relative to the sun. The shadowing of one cell of a group of cells on one side of the mid-cell reduces the power of that group substantially so that full power from the group of cells on the other side of the mid-cell drives the motor to reorient the array to the desired attitude. The cell groups each have a full power output at the power rating of the motor. When the array is at the desired attitude the power output of the two groups of cells balances due to their opposite polarity so that the motor remains unpowered.

Effect of rosmarinic acid in motor dysfunction and life span in a mouse model of familial amyotrophic lateral sclerosis.

PubMed

Shimojo, Yosuke; Kosaka, Kunio; Noda, Yoshihiro; Shimizu, Takahiko; Shirasawa, Takuji

2010-03-01

Amyotrophic lateral sclerosis (ALS) is a late-onset progressive neurodegenerative disease affecting motor neurons. About 2% of patients with the disease are associated with mutations in the gene encoding Cu/Zn superoxide dismutase (SOD1). The purpose of this study is to assess the effect of rosemary extract and its major constituents, rosmarinic acid (RA) and carnosic acid (CA), in human SOD1 G93A transgenic mice, which are well-established mouse models for ALS. The present study demonstrates that intraperitoneal administration of rosemary extract or RA from the presymptomatic stage significantly delayed motor dysfunction in paw grip endurance tests, attenuated the degeneration of motor neurons, and extended the life span of ALS model mice. In addition, RA administration significantly improved the clinical score and suppressed body weight loss compared with a vehicle-treated group. In conclusion, this study provides the first report that rosemary extract and, especially, RA have preventive effects in the mouse model of ALS.

The contribution of mouse models to understanding the pathogenesis of spinal muscular atrophy

PubMed Central

Sleigh, James N.; Gillingwater, Thomas H.; Talbot, Kevin

2011-01-01

Spinal muscular atrophy (SMA), which is caused by inactivating mutations in the survival motor neuron 1 (SMN1) gene, is characterized by loss of lower motor neurons in the spinal cord. The gene encoding SMN is very highly conserved in evolution, allowing the disease to be modeled in a range of species. The similarities in anatomy and physiology to the human neuromuscular system, coupled with the ease of genetic manipulation, make the mouse the most suitable model for exploring the basic pathogenesis of motor neuron loss and for testing potential treatments. Therapies that increase SMN levels, either through direct viral delivery or by enhancing full-length SMN protein expression from the SMN1 paralog, SMN2, are approaching the translational stage of development. It is therefore timely to consider the role of mouse models in addressing aspects of disease pathogenesis that are most relevant to SMA therapy. Here, we review evidence suggesting that the apparent selective vulnerability of motor neurons to SMN deficiency is relative rather than absolute, signifying that therapies will need to be delivered systemically. We also consider evidence from mouse models suggesting that SMN has its predominant action on the neuromuscular system in early postnatal life, during a discrete phase of development. Data from these experiments suggest that the timing of therapy to increase SMN levels might be crucial. The extent to which SMN is required for the maintenance of motor neurons in later life and whether augmenting its levels could treat degenerative motor neuron diseases, such as amyotrophic lateral sclerosis (ALS), requires further exploration. PMID:21708901

System and method for determining stator winding resistance in an AC motor

DOEpatents

Lu, Bin [Kenosha, WI; Habetler, Thomas G [Snellville, GA; Zhang, Pinjia [Atlanta, GA; Theisen, Peter J [West Bend, WI

2011-05-31

A system and method for determining stator winding resistance in an AC motor is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of an AC motor. The circuit includes at least one contactor and at least one switch to control current flow and terminal voltages in the AC motor. The system also includes a controller connected to the circuit and configured to modify a switching time of the at least one switch to create a DC component in an output of the system corresponding to an input to the AC motor and determine a stator winding resistance of the AC motor based on the injected DC component of the voltage and current.

Protein translocation channel of mitochondrial inner membrane and matrix-exposed import motor communicate via two-domain coupling protein.

PubMed

Banerjee, Rupa; Gladkova, Christina; Mapa, Koyeli; Witte, Gregor; Mokranjac, Dejana

2015-12-29

The majority of mitochondrial proteins are targeted to mitochondria by N-terminal presequences and use the TIM23 complex for their translocation across the mitochondrial inner membrane. During import, translocation through the channel in the inner membrane is coupled to the ATP-dependent action of an Hsp70-based import motor at the matrix face. How these two processes are coordinated remained unclear. We show here that the two domain structure of Tim44 plays a central role in this process. The N-terminal domain of Tim44 interacts with the components of the import motor, whereas its C-terminal domain interacts with the translocation channel and is in contact with translocating proteins. Our data suggest that the translocation channel and the import motor of the TIM23 complex communicate through rearrangements of the two domains of Tim44 that are stimulated by translocating proteins.

Dual power, constant speed electric motor system

DOEpatents

Kirschbaum, H.S.

1984-07-31

A dual capacity permanent split capacitor electric motor system is provided with a stator having main and auxiliary windings. The main stator winding includes two winding sections which are connected in parallel with each other and across a pair of line terminals while the auxiliary winding is connected in series with a capacitor to form a circuit branch which is connected between the line terminals for operation at a first output power level. Switching means are provided to reconnect the main stator winding sections in series with each other and in series with a second capacitor to form a circuit branch which is connected between the line terminals while the stator auxiliary winding is connected directly between the line terminals for operation at a second output power level. Automatic rotation reversal occurs when the motor switches from the first to the second output power level. 6 figs.

Dual power, constant speed electric motor system

DOEpatents

Kirschbaum, Herbert S.

1984-01-01

A dual capacity permanent split capacitor electric motor system is provided with a stator having main and auxiliary windings. The main stator winding includes two winding sections which are connected in parallel with each other and across a pair of line terminals while the auxiliary winding is connected in series with a capacitor to form a circuit branch which is connected between the line terminals for operation at a first output power level. Switching means are provided to reconnect the main stator winding sections in series with each other and in series with a second capacitor to form a circuit branch which is connected between the line terminals while the stator auxiliary winding is connected directly between the line terminals for operation at a second output power level. Automatic rotation reversal occurs when the motor switches from the first to the second output power level.

Overexpression of survival motor neuron improves neuromuscular function and motor neuron survival in mutant SOD1 mice.

PubMed

Turner, Bradley J; Alfazema, Neza; Sheean, Rebecca K; Sleigh, James N; Davies, Kay E; Horne, Malcolm K; Talbot, Kevin

2014-04-01

Spinal muscular atrophy results from diminished levels of survival motor neuron (SMN) protein in spinal motor neurons. Low levels of SMN also occur in models of amyotrophic lateral sclerosis (ALS) caused by mutant superoxide dismutase 1 (SOD1) and genetic reduction of SMN levels exacerbates the phenotype of transgenic SOD1(G93A) mice. Here, we demonstrate that SMN protein is significantly reduced in the spinal cords of patients with sporadic ALS. To test the potential of SMN as a modifier of ALS, we overexpressed SMN in 2 different strains of SOD1(G93A) mice. Neuronal overexpression of SMN significantly preserved locomotor function, rescued motor neurons, and attenuated astrogliosis in spinal cords of SOD1(G93A) mice. Despite this, survival was not prolonged, most likely resulting from SMN mislocalization and depletion of gems in motor neurons of symptomatic mice. Our results reveal that SMN upregulation slows locomotor deficit onset and motor neuron loss in this mouse model of ALS. However, disruption of SMN nuclear complexes by high levels of mutant SOD1, even in the presence of SMN overexpression, might limit its survival promoting effects in this specific mouse model. Studies in emerging mouse models of ALS are therefore warranted to further explore the potential of SMN as a modifier of ALS. Copyright © 2014 Elsevier Inc. All rights reserved.

The Absence of Sensory Axon Bifurcation Affects Nociception and Termination Fields of Afferents in the Spinal Cord

PubMed Central

Tröster, Philip; Haseleu, Julia; Petersen, Jonas; Drees, Oliver; Schmidtko, Achim; Schwaller, Frederick; Lewin, Gary R.; Ter-Avetisyan, Gohar; Winter, York; Peters, Stefanie; Feil, Susanne; Feil, Robert; Rathjen, Fritz G.; Schmidt, Hannes

2018-01-01

A cGMP signaling cascade composed of C-type natriuretic peptide, the guanylyl cyclase receptor Npr2 and cGMP-dependent protein kinase I (cGKI) controls the bifurcation of sensory axons upon entering the spinal cord during embryonic development. However, the impact of axon bifurcation on sensory processing in adulthood remains poorly understood. To investigate the functional consequences of impaired axon bifurcation during adult stages we generated conditional mouse mutants of Npr2 and cGKI (Npr2fl/fl;Wnt1Cre and cGKIKO/fl;Wnt1Cre) that lack sensory axon bifurcation in the absence of additional phenotypes observed in the global knockout mice. Cholera toxin labeling in digits of the hind paw demonstrated an altered shape of sensory neuron termination fields in the spinal cord of conditional Npr2 mouse mutants. Behavioral testing of both sexes indicated that noxious heat sensation and nociception induced by chemical irritants are impaired in the mutants, whereas responses to cold sensation, mechanical stimulation, and motor coordination are not affected. Recordings from C-fiber nociceptors in the hind limb skin showed that Npr2 function was not required to maintain normal heat sensitivity of peripheral nociceptors. Thus, the altered behavioral responses to noxious heat found in Npr2fl/fl;Wnt1Cre mice is not due to an impaired C-fiber function. Overall, these data point to a critical role of axonal bifurcation for the processing of pain induced by heat or chemical stimuli. PMID:29472841

Stream-related preferences of inputs to the superior colliculus from areas of dorsal and ventral streams of mouse visual cortex.

PubMed

Wang, Quanxin; Burkhalter, Andreas

2013-01-23

Previous studies of intracortical connections in mouse visual cortex have revealed two subnetworks that resemble the dorsal and ventral streams in primates. Although calcium imaging studies have shown that many areas of the ventral stream have high spatial acuity whereas areas of the dorsal stream are highly sensitive for transient visual stimuli, there are some functional inconsistencies that challenge a simple grouping into "what/perception" and "where/action" streams known in primates. The superior colliculus (SC) is a major center for processing of multimodal sensory information and the motor control of orienting the eyes, head, and body. Visual processing is performed in superficial layers, whereas premotor activity is generated in deep layers of the SC. Because the SC is known to receive input from visual cortex, we asked whether the projections from 10 visual areas of the dorsal and ventral streams terminate in differential depth profiles within the SC. We found that inputs from primary visual cortex are by far the strongest. Projections from the ventral stream were substantially weaker, whereas the sparsest input originated from areas of the dorsal stream. Importantly, we found that ventral stream inputs terminated in superficial layers, whereas dorsal stream inputs tended to be patchy and either projected equally to superficial and deep layers or strongly preferred deep layers. The results suggest that the anatomically defined ventral and dorsal streams contain areas that belong to distinct functional systems, specialized for the processing of visual information and visually guided action, respectively.

Reducing C-Terminal-Truncated Alpha-Synuclein by Immunotherapy Attenuates Neurodegeneration and Propagation in Parkinson's Disease-Like Models

PubMed Central

Games, Dora; Valera, Elvira; Spencer, Brian; Rockenstein, Edward; Mante, Michael; Adame, Anthony; Patrick, Christina; Ubhi, Kiren; Nuber, Silke; Sacayon, Patricia; Zago, Wagner; Seubert, Peter; Barbour, Robin; Schenk, Dale

2014-01-01

Parkinson's disease (PD) and dementia with Lewy bodies (DLB) are common neurodegenerative disorders of the aging population, characterized by progressive and abnormal accumulation of α-synuclein (α-syn). Recent studies have shown that C-terminus (CT) truncation and propagation of α-syn play a role in the pathogenesis of PD/DLB. Therefore, we explored the effect of passive immunization against the CT of α-syn in the mThy1-α-syn transgenic (tg) mouse model, which resembles the striato-nigral and motor deficits of PD. Mice were immunized with the new monoclonal antibodies 1H7, 5C1, or 5D12, all directed against the CT of α-syn. CT α-syn antibodies attenuated synaptic and axonal pathology, reduced the accumulation of CT-truncated α-syn (CT-α-syn) in axons, rescued the loss of tyrosine hydroxylase fibers in striatum, and improved motor and memory deficits. Among them, 1H7 and 5C1 were most effective at decreasing levels of CT-α-syn and higher-molecular-weight aggregates. Furthermore, in vitro studies showed that preincubation of recombinant α-syn with 1H7 and 5C1 prevented CT cleavage of α-syn. In a cell-based system, CT antibodies reduced cell-to-cell propagation of full-length α-syn, but not of the CT-α-syn that lacked the 118–126 aa recognition site needed for antibody binding. Furthermore, the results obtained after lentiviral expression of α-syn suggest that antibodies might be blocking the extracellular truncation of α-syn by calpain-1. Together, these results demonstrate that antibodies against the CT of α-syn reduce levels of CT-truncated fragments of the protein and its propagation, thus ameliorating PD-like pathology and improving behavioral and motor functions in a mouse model of this disease. PMID:25009275

Reducing C-terminal-truncated alpha-synuclein by immunotherapy attenuates neurodegeneration and propagation in Parkinson's disease-like models.

PubMed

Games, Dora; Valera, Elvira; Spencer, Brian; Rockenstein, Edward; Mante, Michael; Adame, Anthony; Patrick, Christina; Ubhi, Kiren; Nuber, Silke; Sacayon, Patricia; Zago, Wagner; Seubert, Peter; Barbour, Robin; Schenk, Dale; Masliah, Eliezer

2014-07-09

Parkinson's disease (PD) and dementia with Lewy bodies (DLB) are common neurodegenerative disorders of the aging population, characterized by progressive and abnormal accumulation of α-synuclein (α-syn). Recent studies have shown that C-terminus (CT) truncation and propagation of α-syn play a role in the pathogenesis of PD/DLB. Therefore, we explored the effect of passive immunization against the CT of α-syn in the mThy1-α-syn transgenic (tg) mouse model, which resembles the striato-nigral and motor deficits of PD. Mice were immunized with the new monoclonal antibodies 1H7, 5C1, or 5D12, all directed against the CT of α-syn. CT α-syn antibodies attenuated synaptic and axonal pathology, reduced the accumulation of CT-truncated α-syn (CT-α-syn) in axons, rescued the loss of tyrosine hydroxylase fibers in striatum, and improved motor and memory deficits. Among them, 1H7 and 5C1 were most effective at decreasing levels of CT-α-syn and higher-molecular-weight aggregates. Furthermore, in vitro studies showed that preincubation of recombinant α-syn with 1H7 and 5C1 prevented CT cleavage of α-syn. In a cell-based system, CT antibodies reduced cell-to-cell propagation of full-length α-syn, but not of the CT-α-syn that lacked the 118-126 aa recognition site needed for antibody binding. Furthermore, the results obtained after lentiviral expression of α-syn suggest that antibodies might be blocking the extracellular truncation of α-syn by calpain-1. Together, these results demonstrate that antibodies against the CT of α-syn reduce levels of CT-truncated fragments of the protein and its propagation, thus ameliorating PD-like pathology and improving behavioral and motor functions in a mouse model of this disease. Copyright © 2014 the authors 0270-6474/14/349441-14$15.00/0.

Decreased number and increased volume with mitochondrial enlargement of cerebellar synaptic terminals in a mouse model of chronic demyelination.

PubMed

Nguyen, Huy Bang; Sui, Yang; Thai, Truc Quynh; Ikenaka, Kazuhiro; Oda, Toshiyuki; Ohno, Nobuhiko

2018-05-23

Impaired nerve conduction, axonal degeneration, and synaptic alterations contribute to neurological disabilities in inflammatory demyelinating diseases. Cerebellar dysfunction is associated with demyelinating disorders, but the alterations of axon terminals in cerebellar gray matter during chronic demyelination are still unclear. We analyzed the morphological and ultrastructural changes of climbing fiber terminals in a mouse model of hereditary chronic demyelination. Three-dimensional ultrastructural analyses using serial block-face scanning electron microscopy and immunostaining for synaptic markers were performed in a demyelination mouse model caused by extra copies of myelin gene (PLP4e). At 1 month old, many myelinated axons were observed in PLP4e and wild-type mice, but demyelinated axons and axons with abnormally thin myelin were prominent in PLP4e mice at 5 months old. The density of climbing fiber terminals was significantly reduced in PLP4e mice at 5 months old. Reconstruction of climbing fiber terminals revealed that PLP4e climbing fibers had increased varicosity volume and enlarged mitochondria in the varicosities at 5-month-old mice. These results suggest that chronic demyelination is associated with alterations and loss of climbing fiber terminals in the cerebellar cortex, and that synaptic changes may contribute to cerebellar phenotypes observed in hereditary demyelinating disorders.

System and method for monitoring and controlling stator winding temperature in a de-energized AC motor

DOEpatents

Lu, Bin [Kenosha, WI; Luebke, Charles John [Sussex, WI; Habetler, Thomas G [Snellville, GA; Zhang, Pinjia [Atlanta, GA; Becker, Scott K [Oak Creek, WI

2011-12-27

A system and method for measuring and controlling stator winding temperature in an AC motor while idling is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of a multi-phase AC motor. The circuit further includes a plurality of switching devices to control current flow and terminal voltages in the multi-phase AC motor and a controller connected to the circuit. The controller is configured to activate the plurality of switching devices to create a DC signal in an output of the motor control device corresponding to an input to the multi-phase AC motor, determine or estimate a stator winding resistance of the multi-phase AC motor based on the DC signal, and estimate a stator temperature from the stator winding resistance. Temperature can then be controlled and regulated by DC injection into the stator windings.

The development of behavioral abnormalities in the motor neuron degeneration (mnd) mouse.

PubMed

Bolivar, Valerie J; Scott Ganus, J; Messer, Anne

2002-05-24

The motor neuron degeneration (mnd) mouse, which has widespread abnormal accumulating lipoprotein and neuronal degeneration, has a mutation in CLN8, the gene for human progressive epilepsy with mental retardation (EPMR). EPMR is one of the neuronal ceroid lipofuscinoses (NCLs), a group of neurological disorders characterized by autofluorescent lipopigment accumulation, blindness, seizures, motor deterioration, and dementia. The human phenotype of EPMR suggests that, in addition to the motor symptoms previously categorized, various types of progressive behavioral abnormalities would be expected in mnd mice. We have therefore examined exploratory behavior, fear conditioning, and aggression in 2-3 month and 4-5 month old male mnd mice and age-matched C57BL/6 (B6) controls. The mnd mice displayed increased activity with decreased habituation in the activity monitor, poor contextual and cued memory, and heightened aggression relative to B6 controls. These behavioral deficits were most prominent at 4-5 months of age, which is prior to the onset of gross motor symptoms at 6 months. Our results provide a link from the mutation via pathology to a quantifiable multidimensional behavioral phenotype of this naturally occurring mouse model of NCL.

Non-Aggregating Tau Phosphorylation by Cyclin-Dependent Kinase 5 Contributes to Motor Neuron Degeneration in Spinal Muscular Atrophy

PubMed Central

Miller, Nimrod; Feng, Zhihua; Edens, Brittany M.; Yang, Ben; Shi, Han; Sze, Christie C.; Hong, Benjamin Taige; Su, Susan C.; Cantu, Jorge A.; Topczewski, Jacek; Crawford, Thomas O.; Ko, Chien-Ping; Sumner, Charlotte J.; Ma, Long

2015-01-01

Mechanisms underlying motor neuron degeneration in spinal muscular atrophy (SMA), the leading inherited cause of infant mortality, remain largely unknown. Many studies have established the importance of hyperphosphorylation of the microtubule-associated protein tau in various neurodegenerative disorders, including Alzheimer's and Parkinson's diseases. However, tau phosphorylation in SMA pathogenesis has yet to be investigated. Here we show that tau phosphorylation on serine 202 (S202) and threonine 205 (T205) is increased significantly in SMA motor neurons using two SMA mouse models and human SMA patient spinal cord samples. Interestingly, phosphorylated tau does not form aggregates in motor neurons or neuromuscular junctions (NMJs), even at late stages of SMA disease, distinguishing it from other tauopathies. Hyperphosphorylation of tau on S202 and T205 is mediated by cyclin-dependent kinase 5 (Cdk5) in SMA disease condition, because tau phosphorylation at these sites is significantly reduced in Cdk5 knock-out mice; genetic knock-out of Cdk5 activating subunit p35 in an SMA mouse model also leads to reduced tau phosphorylation on S202 and T205 in the SMA;p35−/− compound mutant mice. In addition, expression of the phosphorylation-deficient tauS202A,T205A mutant alleviates motor neuron defects in a zebrafish SMA model in vivo and mouse motor neuron degeneration in culture, whereas expression of phosphorylation-mimetic tauS202E,T205E promotes motor neuron defects. More importantly, genetic knock-out of tau in SMA mice rescues synapse stripping on motor neurons, NMJ denervation, and motor neuron degeneration in vivo. Altogether, our findings suggest a novel mechanism for SMA pathogenesis in which hyperphosphorylation of non-aggregating tau by Cdk5 contributes to motor neuron degeneration. PMID:25878277

The Scaffolding Protein, Grb2-associated Binder-1, in Skeletal Muscles and Terminal Schwann Cells Regulates Postnatal Neuromuscular Synapse Maturation

PubMed Central

Park, So Young; Jang, So Young; Shin, Yoon Kyoung; Jung, Dong Keun; Yoon, Byeol A; Kim, Jong Kook; Jo, Young Rae; Lee, Hye Jeong

2017-01-01

The vertebrate neuromuscular junction (NMJ) is considered as a “tripartite synapse” consisting of a motor axon terminal, a muscle endplate, and terminal Schwann cells that envelope the motor axon terminal. The neuregulin 1 (NRG1)-ErbB2 signaling pathway plays an important role in the development of the NMJ. We previously showed that Grb2-associated binder 1 (Gab1), a scaffolding mediator of receptor tyrosine kinase signaling, is required for NRG1-induced peripheral nerve myelination. Here, we determined the role of Gab1 in the development of the NMJ using muscle-specific conditional Gab1 knockout mice. The mutant mice showed delayed postnatal maturation of the NMJ. Furthermore, the selective loss of the gab1 gene in terminal Schwann cells produced delayed synaptic elimination with abnormal morphology of the motor endplate, suggesting that Gab1 in both muscles and terminal Schwann cells is required for proper NMJ development. Gab1 in terminal Schwann cells appeared to regulate the number and process elongation of terminal Schwann cells during synaptic elimination. However, Gab2 knockout mice did not show any defects in the development of the NMJ. Considering the role of Gab1 in postnatal peripheral nerve myelination, our findings suggest that Gab1 is a pleiotropic and important component of NRG1 signals during postnatal development of the peripheral neuromuscular system. PMID:28680299

The Scaffolding Protein, Grb2-associated Binder-1, in Skeletal Muscles and Terminal Schwann Cells Regulates Postnatal Neuromuscular Synapse Maturation.

PubMed

Park, So Young; Jang, So Young; Shin, Yoon Kyoung; Jung, Dong Keun; Yoon, Byeol A; Kim, Jong Kook; Jo, Young Rae; Lee, Hye Jeong; Park, Hwan Tae

2017-06-01

The vertebrate neuromuscular junction (NMJ) is considered as a "tripartite synapse" consisting of a motor axon terminal, a muscle endplate, and terminal Schwann cells that envelope the motor axon terminal. The neuregulin 1 (NRG1)-ErbB2 signaling pathway plays an important role in the development of the NMJ. We previously showed that Grb2-associated binder 1 (Gab1), a scaffolding mediator of receptor tyrosine kinase signaling, is required for NRG1-induced peripheral nerve myelination. Here, we determined the role of Gab1 in the development of the NMJ using muscle-specific conditional Gab1 knockout mice. The mutant mice showed delayed postnatal maturation of the NMJ. Furthermore, the selective loss of the gab1 gene in terminal Schwann cells produced delayed synaptic elimination with abnormal morphology of the motor endplate, suggesting that Gab1 in both muscles and terminal Schwann cells is required for proper NMJ development. Gab1 in terminal Schwann cells appeared to regulate the number and process elongation of terminal Schwann cells during synaptic elimination. However, Gab2 knockout mice did not show any defects in the development of the NMJ. Considering the role of Gab1 in postnatal peripheral nerve myelination, our findings suggest that Gab1 is a pleiotropic and important component of NRG1 signals during postnatal development of the peripheral neuromuscular system.

Assisting People with Multiple Disabilities and Minimal Motor Behavior to Improve Computer Drag-and-Drop Efficiency through a Mouse Wheel

ERIC Educational Resources Information Center

Shih, Ching-Hsiang

2011-01-01

This study evaluated whether two people with multiple disabilities and minimal motor behavior would be able to improve their Drag-and-Drop (DnD) performance using their finger/thumb poke ability with a mouse scroll wheel through a Dynamic Drag-and-Drop Assistive Program (DDnDAP). A multiple probe design across participants was used in this study…

YAC cloning Mus musculus telomeric DNA: physical, genetic, in situ and STS markers for the distal telomere of chromosome 10.

PubMed

Kipling, D; Wilson, H E; Thomson, E J; Cooke, H J

1995-06-01

Three Mus musculus DBA/2 YAC libraries were constructed using a half-YAC telomere cloning vector. This functional complementation approach yields libraries which include terminal restriction fragments of the mouse genome. Screening all three libraries led to the isolation of 32 independent clones which carry linear YACs containing the mouse terminal repeat sequence, (TTAGGG)n. These YACs provide a resource to isolate regions of the mouse genome close to chromosome termini and excluded from existing conventional YAC libraries. To demonstrate their utility, a hybridization probe was isolated from Mtel-1, the first (TTAGGG)n-containing YAC isolated. This probe detects a approximately 70 kb Kpnl fragment in the mouse genome which is sensitive to pretreatment with BAL31 exonuclease. A PCR-based genetic marker generated from the sequence of this probe maps 4.4 cM from the most distal anchor locus on chromosome 10 in the EUCIB interspecific backcross. STS primers for this locus, D10Hgu1, were used to isolate YAC 110F4 from a commercially available mouse YAC library. Fluorescence in situ hybridization demonstrates that YAC 110F4 hybridizes to the distal telomere of chromosome 10. Clones in this collection of telomere YACs therefore partially overlap clones in conventional YAC libraries, and thus the previously unavailable terminal regions of the mouse genome can now be linked with the developing mouse STS YAC contig. Genetic markers such as D10Hgu1 allow the ends of the mouse genetic map to be defined, thus closing the map.

Palisade endings: cholinergic sensory organs or effector organs?

PubMed

Blumer, Roland; Konakci, Kadriye Zeynep; Pomikal, Christine; Wieczorek, Grazyna; Lukas, Julius-Robert; Streicher, Johannes

2009-03-01

This study aims to complement the authors' prior findings on palisade endings in extraocular muscles (EOMs) of monkeys, and to clarify whether palisade endings are cholinergic motor or cholinergic sensory. Macaque monkeys (Macaca fascicularis, n = 10) of both sexes were analyzed using three-dimensional (3D) reconstructions, confocal laser scanning microscopy (CLSM), and conventional/immuno transmission electron microscopy (TEM). For CLSM, we used three combinations of triple fluorescent labeling. EOM wholemounts were labeled with cholinergic markers, including choline acetyltransferase (ChAT), choline transporter (ChT), vesicular acetylcholine transporter (VAChT), and a classical postsynaptic marker for motor terminals, namely alpha-bungarotoxin. Muscle fibers were counterstained with phalloidin. 3D reconstructions were done of triple-labeled palisade endings. For immuno TEM, tissue was labeled with antibody against ChAT. Concordant with prior findings, the authors demonstrated that palisade endings at the muscle fiber tips arose from nerve fibers that are ChAT-positive. In 25% of the cases, axons forming palisade endings established multiple neuromuscular contacts outside the palisade complex. Such additional neuromuscular contacts were motor terminals, as demonstrated by alpha-bungarotoxin binding. All palisade endings established nerve terminals on the tendon. In 40% of the palisade endings, nerve terminals were observed on the muscle fiber as well. Neurotendinous contacts and neuromuscular contacts in palisade endings were ChT/ChAT/VAChT-immunoreactive. Neuromuscular contacts exhibited structural features of motor terminals and were also alpha-bungarotoxin positive. The present study ascertained that palisade endings are cholinergic motor organs. Therefore, it was concluded that palisade endings are not candidates to provide eye-position signals.

Cloning and characterization of full-length mouse thymidine kinase 2: the N-terminal sequence directs import of the precursor protein into mitochondria.

PubMed Central

Wang, L; Eriksson, S

2000-01-01

The subcellular localization of mitochondrial thymidine kinase (TK2) has been questioned, since no mitochondrial targeting sequences have been found in cloned human TK2 cDNAs. Here we report the cloning of mouse TK2 cDNA from a mouse full-length enriched cDNA library. The mouse TK2 cDNA codes for a protein of 270 amino acids, with a 40-amino-acid presumed N-terminal mitochondrial targeting signal. In vitro translation and translocation experiments with purified rat mitochondria confirmed that the N-terminal sequence directed import of the precursor TK2 into the mitochondrial matrix. A single 2.4 kb mRNA transcript was detected in most tissues examined, except in liver, where an additional shorter (1.0 kb) transcript was also observed. There was no correlation between the tissue distribution of TK2 activity and the expression of TK2 mRNA. Full-length mouse TK2 protein and two N-terminally truncated forms, one of which corresponds to the mitochondrial form of TK2 and a shorter form corresponding to the previously characterized recombinant human TK2, were expressed in Escherichia coli and affinity purified. All three forms of TK2 phosphorylated thymidine, deoxycytidine and 2'-deoxyuridine, but with different kinetic efficiencies. A number of cytostatic pyrimidine nucleoside analogues were also tested and shown to be good substrates for the various forms of TK2. The active form of full-length mouse TK2 was a dimer, as judged by Superdex 200 chromatography. These results enhance our understanding of the structure and function of TK2, and may help to explain the mitochondrial disorder, mitochondrial neurogastrointestinal encephalomyopathy. PMID:11023833

The effects of humoral agents on the myoelectrical activity of the terminal ileum

PubMed Central

Waterfall, W. E.; Brown, B. H.; Duthie, H. L.; Whittaker, G. E.

1972-01-01

Electrical and motor activities of the terminal ileum have been recorded in 25 patients with a permanent ileostomy. Records made within a week of formation of the ileostomy show an increased motor activity which is significantly reduced after four weeks. Intravenous infusion of gastrin, 1 μg/kg-hr, was accompanied by a significant increase in action potentials and in the percentage motility. Conversely, secretin 1 unit/kg-hr was associated with a decrease in action potentials and in percentage motor activity. ImagesFig. 2Fig. 3 PMID:5069728

Motor neuron mitochondrial dysfunction in spinal muscular atrophy

PubMed Central

Miller, Nimrod; Shi, Han; Zelikovich, Aaron S.; Ma, Yong-Chao

2016-01-01

Spinal muscular atrophy (SMA), the leading genetic cause of infant mortality, predominantly affects high metabolic tissues including motor neurons, skeletal muscles and the heart. Although the genetic cause of SMA has been identified, mechanisms underlying tissue-specific vulnerability are not well understood. To study these mechanisms, we carried out a deep sequencing analysis of the transcriptome of spinal motor neurons in an SMA mouse model, in which we unexpectedly found changes in many genes associated with mitochondrial bioenergetics. Importantly, functional measurement of mitochondrial activities showed decreased basal and maximal mitochondrial respiration in motor neurons from SMA mice. Using a reduction-oxidation sensitive GFP and fluorescence sensors specifically targeted to mitochondria, we found increased oxidative stress level and impaired mitochondrial membrane potential in motor neurons affected by SMA. In addition, mitochondrial mobility was impaired in SMA disease conditions, with decreased retrograde transport but no effect on anterograde transport. We also found significantly increased fragmentation of the mitochondrial network in primary motor neurons from SMA mice, with no change in mitochondria density. Electron microscopy study of SMA mouse spinal cord revealed mitochondria fragmentation, edema and concentric lamellar inclusions in motor neurons affected by the disease. Intriguingly, these functional and structural deficiencies in the SMA mouse model occur during the presymptomatic stage of disease, suggesting a role in initiating SMA. Altogether, our findings reveal a critical role for mitochondrial defects in SMA pathogenesis and suggest a novel target for improving tissue health in the disease. PMID:27488123

The metabotropic glutamate receptor activates the lipid kinase PI3K in Drosophila motor neurons through the calcium/calmodulin-dependent protein kinase II and the nonreceptor tyrosine protein kinase DFak.

PubMed

Chun-Jen Lin, Curtis; Summerville, James B; Howlett, Eric; Stern, Michael

2011-07-01

Ligand activation of the metabotropic glutamate receptor (mGluR) activates the lipid kinase PI3K in both the mammalian central nervous system and Drosophila motor nerve terminal. In several subregions of the mammalian brain, mGluR-mediated PI3K activation is essential for a form of synaptic plasticity termed long-term depression (LTD), which is implicated in neurological diseases such as fragile X and autism. In Drosophila larval motor neurons, ligand activation of DmGluRA, the sole Drosophila mGluR, similarly mediates a PI3K-dependent downregulation of neuronal activity. The mechanism by which mGluR activates PI3K remains incompletely understood in either mammals or Drosophila. Here we identify CaMKII and the nonreceptor tyrosine kinase DFak as critical intermediates in the DmGluRA-dependent activation of PI3K at Drosophila motor nerve terminals. We find that transgene-induced CaMKII inhibition or the DFak(CG1) null mutation each block the ability of glutamate application to activate PI3K in larval motor nerve terminals, whereas transgene-induced CaMKII activation increases PI3K activity in motor nerve terminals in a DFak-dependent manner, even in the absence of glutamate application. We also find that CaMKII activation induces other PI3K-dependent effects, such as increased motor axon diameter and increased synapse number at the larval neuromuscular junction. CaMKII, but not PI3K, requires DFak activity for these increases. We conclude that the activation of PI3K by DmGluRA is mediated by CaMKII and DFak.

Cilia/Ift protein and motor -related bone diseases and mouse models.

PubMed

Yuan, Xue; Yang, Shuying

2015-01-01

Primary cilia are essential cellular organelles projecting from the cell surface to sense and transduce developmental signaling. They are tiny but have complicated structures containing microtubule (MT)-based internal structures (the axoneme) and mother centriole formed basal body. Intraflagellar transport (Ift) operated by Ift proteins and motors are indispensable for cilia formation and function. Mutations in Ift proteins or Ift motors cause various human diseases, some of which have severe bone defects. Over the last few decades, major advances have occurred in understanding the roles of these proteins and cilia in bone development and remodeling by examining cilia/Ift protein-related human diseases and establishing mouse transgenic models. In this review, we describe current advances in the understanding of the cilia/Ift structure and function. We further summarize cilia/Ift-related human diseases and current mouse models with an emphasis on bone-related phenotypes, cilia morphology, and signaling pathways.

Social Threat and Motor Resonance: When a Menacing Outgroup Delays Motor Response

PubMed Central

Capellini, Roberta; Sacchi, Simona; Ricciardelli, Paola; Actis-Grosso, Rossana

2016-01-01

Motor resonance (MR) involves the activation of matching motor representations while observing others’ actions. Recent research has shown that such a phenomenon is likely to be influenced by higher order variables such as social factors (e.g., ethnic group membership). The present study investigates whether and how the perception of a social threat elicited by an outgroup member and by contextual cues can modulate motor responses while an individual observes others’ movements. In an experimental study based on an action observation paradigm, we asked participants to provide answers through computer mouse movements (MouseTracker). We manipulated the agents’ group membership (ingroup vs. outgroup) and the social valence of the objects present in a context (neutral vs. threatening) to elicit social menace through contextual cues. Response times and computer mouse trajectories were recorded. The results show a higher level of MR (i.e., participants started to respond earlier and were faster at responding) when observing an action performed by the ingroup members rather than by the outgroup members only when threatening objects are present in a given context. Participants seem to resonate better with their ingroup; conversely, the outgroup member movements tend to delay motor responses. Therefore, we extend prior research going beyond the general ingroup bias effect on MR and showing that the interaction between membership and contextual cues is likely to elicit threat-related stereotypes. Practical implications of these findings are discussed. PMID:27847491

49 CFR 374.309 - Terminal facilities.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 5 2010-10-01 2010-10-01 false Terminal facilities. 374.309 Section 374.309... REGULATIONS Adequacy of Intercity Motor Common Carrier Passenger Service § 374.309 Terminal facilities. (a... attendants and be regularly patrolled. (b) Outside facilities. At terminals and stations that are closed when...

Motor Experience Reprograms Development of a Genetically-Altered Bilateral Corticospinal Motor Circuit

PubMed Central

Serradj, Najet

2016-01-01

Evidence suggests that motor experience plays a role in shaping development of the corticospinal system and voluntary motor control, which is a key motor function of the system. Here we used a mouse model with conditional forebrain deletion of the gene for EphA4 (Emx1-Cre:EphA4tm2Kldr), which regulates development of the laterality of corticospinal tract (CST). We combined study of Emx1-Cre:EphA4tm2Kldr with unilateral forelimb constraint during development to expand our understanding of experience-dependent CST development from both basic and translational perspectives. This mouse develops dense ipsilateral CST projections, a bilateral motor cortex motor representation, and bilateral motor phenotypes. Together these phenotypes can be used as readouts of corticospinal system organization and function and the changes brought about by experience. The Emx1-Cre:EphA4tm2Kldr mouse shares features with the common developmental disorder cerebral palsy: bilateral voluntary motor impairments and bilateral CST miswiring. Emx1-Cre:EphA4tm2Kldr mice with typical motor experiences during development display the bilateral phenotype of “mirror” reaching, because of a strongly bilateral motor cortex motor representation and a bilateral CST. By contrast, Emx1-Cre:EphA4tm2Kldr mice that experienced unilateral forelimb constraint from P1 to P30 and tested at maturity had a more contralateral motor cortex motor representation in each hemisphere; more lateralized CST projections; and substantially more lateralized/independent reaching movements. Changes in CST organization and function in this model can be explained by reduced synaptic competition of the CST from the side without developmental forelimb motor experiences. Using this model we show that unilateral constraint largely abrogated the effects of the genetic mutation on CST projections and thus demonstrates how robust and persistent experience-dependent development can be for the establishment of corticospinal system connections and voluntary control. Further, our findings inform the mechanisms of and strategies for developing behavioral therapies to treat bilateral movement impairments and CST miswiring in cerebral palsy. PMID:27673329

Motor Experience Reprograms Development of a Genetically-Altered Bilateral Corticospinal Motor Circuit.

PubMed

Serradj, Najet; Martin, John H

Evidence suggests that motor experience plays a role in shaping development of the corticospinal system and voluntary motor control, which is a key motor function of the system. Here we used a mouse model with conditional forebrain deletion of the gene for EphA4 (Emx1-Cre:EphA4tm2Kldr), which regulates development of the laterality of corticospinal tract (CST). We combined study of Emx1-Cre:EphA4tm2Kldr with unilateral forelimb constraint during development to expand our understanding of experience-dependent CST development from both basic and translational perspectives. This mouse develops dense ipsilateral CST projections, a bilateral motor cortex motor representation, and bilateral motor phenotypes. Together these phenotypes can be used as readouts of corticospinal system organization and function and the changes brought about by experience. The Emx1-Cre:EphA4tm2Kldr mouse shares features with the common developmental disorder cerebral palsy: bilateral voluntary motor impairments and bilateral CST miswiring. Emx1-Cre:EphA4tm2Kldr mice with typical motor experiences during development display the bilateral phenotype of "mirror" reaching, because of a strongly bilateral motor cortex motor representation and a bilateral CST. By contrast, Emx1-Cre:EphA4tm2Kldr mice that experienced unilateral forelimb constraint from P1 to P30 and tested at maturity had a more contralateral motor cortex motor representation in each hemisphere; more lateralized CST projections; and substantially more lateralized/independent reaching movements. Changes in CST organization and function in this model can be explained by reduced synaptic competition of the CST from the side without developmental forelimb motor experiences. Using this model we show that unilateral constraint largely abrogated the effects of the genetic mutation on CST projections and thus demonstrates how robust and persistent experience-dependent development can be for the establishment of corticospinal system connections and voluntary control. Further, our findings inform the mechanisms of and strategies for developing behavioral therapies to treat bilateral movement impairments and CST miswiring in cerebral palsy.

Assessment of motor balance and coordination in mice using the balance beam.

PubMed

Luong, Tinh N; Carlisle, Holly J; Southwell, Amber; Patterson, Paul H

2011-03-10

Brain injury, genetic manipulations, and pharmacological treatments can result in alterations of motor skills in mice. Fine motor coordination and balance can be assessed by the beam walking assay. The goal of this test is for the mouse to stay upright and walk across an elevated narrow beam to a safe platform. This test takes place over 3 consecutive days: 2 days of training and 1 day of testing. Performance on the beam is quantified by measuring the time it takes for the mouse to traverse the beam and the number of paw slips that occur in the process. Here we report the protocol used in our laboratory, and representative results from a cohort of C57BL/6 mice. This task is particularly useful for detecting subtle deficits in motor skills and balance that may not be detected by other motor tests, such as the Rotarod.

Assessment of Motor Balance and Coordination in Mice using the Balance Beam

PubMed Central

Southwell, Amber; Patterson, Paul H.

2011-01-01

Brain injury, genetic manipulations, and pharmacological treatments can result in alterations of motor skills in mice. Fine motor coordination and balance can be assessed by the beam walking assay. The goal of this test is for the mouse to stay upright and walk across an elevated narrow beam to a safe platform. This test takes place over 3 consecutive days: 2 days of training and 1 day of testing. Performance on the beam is quantified by measuring the time it takes for the mouse to traverse the beam and the number of paw slips that occur in the process. Here we report the protocol used in our laboratory, and representative results from a cohort of C57BL/6 mice. This task is particularly useful for detecting subtle deficits in motor skills and balance that may not be detected by other motor tests, such as the Rotarod. PMID:21445033

Comparative evaluation of power factor impovement techniques for squirrel cage induction motors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spee, R.; Wallace, A.K.

1992-04-01

This paper describes the results obtained from a series of tests of relatively simple methods of improving the power factor of squirrel-cage induction motors. The methods, which are evaluated under controlled laboratory conditions for a 10-hp, high-efficiency motor, include terminal voltage reduction; terminal static capacitors; and a floating'' winding with static capacitors. The test results are compared with equivalent circuit model predictions that are then used to identify optimum conditions for each of the power factor improvement techniques compared with the basic induction motor. Finally, the relative economic value, and the implications of component failures, of the three methods aremore » discussed.« less

Spinal Accessory Motor Neurons in the Mouse: A Special Type of Branchial Motor Neuron?

PubMed

Watson, Charles; Tvrdik, Petr

2018-04-16

The spinal accessory nerve arises from motor neurons in the upper cervical spinal cord. The axons of these motor neurons exit dorsal to the ligamentum denticulatum and form the spinal accessory nerve. The nerve ascends in the spinal subarachnoid space to enter the posterior cranial fossa through the foramen magnum. The spinal accessory nerve then turns caudally to exit through the jugular foramen alongside the vagus and glossopharyngeal nerves, and then travels to supply the sternomastoid and trapezius muscles in the neck. The unusual course of the spinal accessory nerve has long prompted speculation that it is not a typical spinal motor nerve and that it might represent a caudal remnant of the branchial motor system. Our cell lineage tracing data, combined with images from public databases, show that the spinal accessory motor neurons in the mouse transiently express Phox2b, a transcription factor that is required for development of brain stem branchial motor nuclei. While this is strong prima facie evidence that the spinal accessory motor neurons should be classified as branchial motor, the evolutionary history of these motor neurons in anamniote vertebrates suggests that they may be considered to be an atypical branchial group that possesses both branchial and somatic characteristics. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

DEVELOPMENT OF THE SIGMA-1 RECEPTOR IN C-TERMINALS OF MOTONEURONS AND COLOCALIZATION WITH THE N,N’-DIMETHYLTRYPTAMINE FORMING ENZYME, INDOLE-N-METHYL TRANSFERASE

PubMed Central

Mavlyutov, Timur A.; Epstein, Miles L.; Liu, Patricia; Verbny, Yakov I.; Ziskind-Conhaim, Lea; Ruoho, Arnold E.

2012-01-01

The function of the sigma-1 receptor (S1R) has been linked to modulating the activities of ion channels and G-protein coupled receptors (GPCR). In the CNS the S1R is expressed ubiquitously but is enriched in mouse motoneurons (MN), where it is localized to subsurface cisternae of cholinergic postsynaptic densities, also known as C-terminals. We found that S1R is enriched in mouse spinal MN at late stages of embryonic development when it is first visualized in the endoplasmic reticulum. S1Rs appear to concentrate at C-terminals of mouse MN only on the second week of postnatal development. We found that Indole-N-methyl transferase (INMT), an enzyme that converts tryptamine into the sigma-1 ligand dimethyltryptamine (DMT), is also localized to postsynaptic sites of C-terminals in close proximity to the S1R. This close association of INMT and SIRs suggest that DMT is synthesized locally to effectively activate S1R in MN. PMID:22265729

Development of the sigma-1 receptor in C-terminals of motoneurons and colocalization with the N,N'-dimethyltryptamine forming enzyme, indole-N-methyl transferase.

PubMed

Mavlyutov, T A; Epstein, M L; Liu, P; Verbny, Y I; Ziskind-Conhaim, L; Ruoho, A E

2012-03-29

The function of the sigma-1 receptor (S1R) has been linked to modulating the activities of ion channels and G-protein-coupled receptors (GPCR). In the CNS, the S1R is expressed ubiquitously but is enriched in mouse motoneurons (MN), where it is localized to subsurface cisternae of cholinergic postsynaptic densities, also known as C-terminals. We found that S1R is enriched in mouse spinal MN at late stages of embryonic development when it is first visualized in the endoplasmic reticulum. S1Rs appear to concentrate at C-terminals of mouse MN only on the second week of postnatal development. We found that indole-N-methyl transferase (INMT), an enzyme that converts tryptamine into the sigma-1 ligand dimethyltryptamine (DMT), is also localized to postsynaptic sites of C-terminals in close proximity to the S1R. This close association of INMT and S1Rs suggest that DMT is synthesized locally to effectively activate S1R in MN. Published by Elsevier Ltd.

Effects of ubiquitin C-terminal hydrolase L1 deficiency on mouse ova.

PubMed

Koyanagi, Sayaka; Hamasaki, Hiroko; Sekiguchi, Satoshi; Hara, Kenshiro; Ishii, Yoshiyuki; Kyuwa, Shigeru; Yoshikawa, Yasuhiro

2012-03-01

Maternal proteins are rapidly degraded by the ubiquitin-proteasome system during oocyte maturation in mice. Ubiquitin C-terminal hydrolase L1 (UCHL1) is highly and specifically expressed in mouse ova and is involved in the polyspermy block. However, the role of UCHL1 in the underlying mechanism of polyspermy block is poorly understood. To address this issue, we performed a comprehensive proteomic analysis to identify maternal proteins that were relevant to the role of UCHL1 in mouse ova using UCHL1-deficient gad. Furthermore, we assessed morphological features in gad mouse ova using transmission electron microscopy. NACHT, LRR, and PYD domain-containing (NALP) family proteins and endoplasmic reticulum (ER) chaperones were identified by proteomic analysis. We also found that the 'maternal antigen that embryos require' (NLRP5 (MATER)) protein level increased significantly in gad mouse ova compared with that in wild-type mice. In an ultrastructural study, gad mouse ova contained less ER in the cortex than in wild-type mice. These results provide new insights into the role of UCHL1 in the mechanism of polyspermy block in mouse ova.

Protein translocation channel of mitochondrial inner membrane and matrix-exposed import motor communicate via two-domain coupling protein

PubMed Central

Banerjee, Rupa; Gladkova, Christina; Mapa, Koyeli; Witte, Gregor; Mokranjac, Dejana

2015-01-01

The majority of mitochondrial proteins are targeted to mitochondria by N-terminal presequences and use the TIM23 complex for their translocation across the mitochondrial inner membrane. During import, translocation through the channel in the inner membrane is coupled to the ATP-dependent action of an Hsp70-based import motor at the matrix face. How these two processes are coordinated remained unclear. We show here that the two domain structure of Tim44 plays a central role in this process. The N-terminal domain of Tim44 interacts with the components of the import motor, whereas its C-terminal domain interacts with the translocation channel and is in contact with translocating proteins. Our data suggest that the translocation channel and the import motor of the TIM23 complex communicate through rearrangements of the two domains of Tim44 that are stimulated by translocating proteins. DOI: http://dx.doi.org/10.7554/eLife.11897.001 PMID:26714107

Cerebellar Plasticity and Motor Learning Deficits in a Copy Number Variation Mouse Model of Autism

PubMed Central

Piochon, Claire; Kloth, Alexander D; Grasselli, Giorgio; Titley, Heather K; Nakayama, Hisako; Hashimoto, Kouichi; Wan, Vivian; Simmons, Dana H; Eissa, Tahra; Nakatani, Jin; Cherskov, Adriana; Miyazaki, Taisuke; Watanabe, Masahiko; Takumi, Toru; Kano, Masanobu; Wang, Samuel S-H; Hansel, Christian

2014-01-01

A common feature of autism spectrum disorder (ASD) is the impairment of motor control and learning, occurring in a majority of children with autism, consistent with perturbation in cerebellar function. Here we report alterations in motor behavior and cerebellar synaptic plasticity in a mouse model (patDp/+) for the human 15q11-13 duplication, one of the most frequently observed genetic aberrations in autism. These mice show ASD-resembling social behavior deficits. We find that in patDp/+ mice delay eyeblink conditioning—a form of cerebellum-dependent motor learning—is impaired, and observe deregulation of a putative cellular mechanism for motor learning, long-term depression (LTD) at parallel fiber-Purkinje cell synapses. Moreover, developmental elimination of surplus climbing fibers—a model for activity-dependent synaptic pruning—is impaired. These findings point to deficits in synaptic plasticity and pruning as potential causes for motor problems and abnormal circuit development in autism. PMID:25418414

Brushless direct-current motors

NASA Technical Reports Server (NTRS)

Bahm, E. J.

1970-01-01

Survey results are presented on the use of unconventional motor windings and switching sequences to optimize performance of brushless dc motors. A motor was built, each coil terminal having a separate, accessible lead. With the shaft and all electronics excluded, length and outside diameter measured 1.25 and 0.75 in., respectively.

77 FR 8898 - Certain Starter Motors and Alternators; Determination Not To Review an Initial Determination...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-15

... joint motion to terminate the investigation as to respondent Electric Motor Service, Inc. (EMS) of Logan... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-755] Certain Starter Motors and... for importation, and the sale within the United States after importation of certain starter motors and...

Efficient differentiation of mouse embryonic stem cells into motor neurons.

PubMed

Wu, Chia-Yen; Whye, Dosh; Mason, Robert W; Wang, Wenlan

2012-06-09

Direct differentiation of embryonic stem (ES) cells into functional motor neurons represents a promising resource to study disease mechanisms, to screen new drug compounds, and to develop new therapies for motor neuron diseases such as spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS). Many current protocols use a combination of retinoic acid (RA) and sonic hedgehog (Shh) to differentiate mouse embryonic stem (mES) cells into motor neurons. However, the differentiation efficiency of mES cells into motor neurons has only met with moderate success. We have developed a two-step differentiation protocol that significantly improves the differentiation efficiency compared with currently established protocols. The first step is to enhance the neuralization process by adding Noggin and fibroblast growth factors (FGFs). Noggin is a bone morphogenetic protein (BMP) antagonist and is implicated in neural induction according to the default model of neurogenesis and results in the formation of anterior neural patterning. FGF signaling acts synergistically with Noggin in inducing neural tissue formation by promoting a posterior neural identity. In this step, mES cells were primed with Noggin, bFGF, and FGF-8 for two days to promote differentiation towards neural lineages. The second step is to induce motor neuron specification. Noggin/FGFs exposed mES cells were incubated with RA and a Shh agonist, Smoothened agonist (SAG), for another 5 days to facilitate motor neuron generation. To monitor the differentiation of mESs into motor neurons, we used an ES cell line derived from a transgenic mouse expressing eGFP under the control of the motor neuron specific promoter Hb9. Using this robust protocol, we achieved 51 ± 0.8% of differentiation efficiency (n = 3; p < 0.01, Student's t-test). Results from immunofluorescent staining showed that GFP+ cells express the motor neuron specific markers, Islet-1 and choline acetyltransferase (ChAT). Our two-step differentiation protocol provides an efficient way to differentiate mES cells into spinal motor neurons.

Computers in the Cop Car: Impact of the Mobile Digital Terminal Technology on Motor Vehicle Theft Clearance and Recovery Rates in a Texas City.

ERIC Educational Resources Information Center

Nunn, Samuel

1993-01-01

Assessed the impact of the Mobile Digital Terminal technology (computers used to communicate with remote crime databases) on motor vehicle theft clearance (arresting a perpetrator) and recovery rates in Fort Worth (Texas), using a time series analysis. Impact has been ambiguous, with little evidence of improved clearance or recovery. (SLD)

Omega-3 Hastens and Omega-6 Delays the Progression of Neuropathology in a Murine Model of Familial ALS.

PubMed

Boumil, Edward F; Vohnoutka, Rishel Brenna; Liu, Yuguan; Lee, Sangmook; Shea, Thomas B

2017-01-01

Amyotrophic lateral sclerosis (ALS) is a progressive disease of motor neurons that has no cure or effective treatment. Any approach that could sustain minor motor function during terminal stages would improve quality of life. We examined the impact of omega-3 (Ω-3) and Ω-6, on motor neuron function in mice expressing mutant human superoxide dismutase-1 (SOD-1), which dominantly confers familial ALS and induces a similar sequence of motor neuron decline and eventual death when expressed in mice. Mice received standard diets supplemented with equivalent amounts of Ω-3 and Ω-6 or a 10x increase in Ω-6 with no change in Ω-3 commencing at 4 weeks of age. Motor function and biochemical/histological parameters were assayed by standard methodologies. Supplementation with equivalent Ω-3 and Ω-6 hastened motor neuron pathology and death, while 10x Ω-6 with no change in Ω-3 significantly delayed motor neuron pathology, including preservation of minor motor neuron function during the terminal stage. In the absence of a cure or treatment, affected individuals may resort to popular nutritional supplements such as Ω-3 as a form of "self-medication". However, our findings and those of other laboratories indicate that such an approach could be harmful. Our findings suggest that a critical balance of Ω-6 and Ω-3 may temporarily preserve motor neuron function during the terminal stages of ALS, which could provide a substantial improvement in quality of life for affected individuals and their caregivers.

Using an Extended Dynamic Drag-and-Drop Assistive Program to Assist People with Multiple Disabilities and Minimal Motor Control to Improve Computer Drag-and-Drop Ability through a Mouse Wheel

ERIC Educational Resources Information Center

Shih, Ching-Hsiang

2012-01-01

Software technology is adopted by the current research to improve the Drag-and-Drop abilities of two people with multiple disabilities and minimal motor control. This goal was realized through a Dynamic Drag-and-Drop Assistive Program (DDnDAP) in which the complex dragging process is replaced by simply poking the mouse wheel and clicking. However,…

The mouse beam walking assay offers improved sensitivity over the mouse rotarod in determining motor coordination deficits induced by benzodiazepines.

PubMed

Stanley, Joanna L; Lincoln, Rachael J; Brown, Terry A; McDonald, Louise M; Dawson, Gerard R; Reynolds, David S

2005-05-01

The mouse rotarod test of motor coordination/sedation is commonly used to predict clinical sedation caused by novel drugs. However, past experience suggests that it lacks the desired degree of sensitivity to be predictive of effects in humans. For example, the benzodiazepine, bretazenil, showed little impairment of mouse rotarod performance, but marked sedation in humans. The aim of the present study was to assess whether the mouse beam walking assay demonstrates: (i) an increased sensitivity over the rotarod and (ii) an increased ability to predict clinically sedative doses of benzodiazepines. The study compared the effects of the full benzodiazepine agonists, diazepam and lorazepam, and the partial agonist, bretazenil, on the mouse rotarod and beam walking assays. Diazepam and lorazepam significantly impaired rotarod performance, although relatively high GABA-A receptor occupancy was required (72% and 93%, respectively), whereas beam walking performance was significantly affected at approximately 30% receptor occupancy. Bretazenil produced significant deficits at 90% and 53% receptor occupancy on the rotarod and beam walking assays, respectively. The results suggest that the mouse beam walking assay is a more sensitive tool for determining benzodiazepine-induced motor coordination deficits than the rotarod. Furthermore, the GABA-A receptor occupancy values at which significant deficits were determined in the beam walking assay are comparable with those observed in clinical positron emission tomography studies using sedative doses of benzodiazepines. These data suggest that the beam walking assay may be able to more accurately predict the clinically sedative doses of novel benzodiazepine-like drugs.

Improved lower extremity pedaling mechanics in individuals with stroke under maximal workloads.

PubMed

Linder, Susan M; Rosenfeldt, Anson B; Bazyk, Andrew S; Koop, Mandy Miller; Ozinga, Sarah; Alberts, Jay L

2018-05-01

Background Individuals with stroke present with motor control deficits resulting in the abnormal activation and timing of agonist and antagonist muscles and inefficient movement patterns. The analysis of pedaling biomechanics provides a window into understanding motor control deficits, which vary as a function of workload. Understanding the relationship between workload and motor control is critical when considering exercise prescription during stroke rehabilitation. Objectives To characterize pedaling kinematics and motor control processes under conditions in which workload was systematically increased to an eventual patient-specific maximum. Methods A cohort study was conducted in which 18 individuals with chronic stroke underwent a maximal exertion cardiopulmonary exercise test on a stationary cycle ergometer, during which pedaling torque was continuously recorded. Measures of force production, pedaling symmetry, and pedaling smoothness were obtained. Results Mean Torque increased significantly (p < 0.05) for both legs from initial to terminal workloads. Mean torque Symmetry Index, calculated for down and upstroke portions of the pedaling action, improved from 0.37(0.29) to 0.29(0.35) during downstroke (p = 0.007), and worsened during the upstroke: -0.37(0.38) to -0.62(0.46) (p < 0.001) from initial to terminal workloads. Low Torque Duration improved from initial to terminal workloads, decreasing from 121.1(52.9) to 58.1(39.6) degrees (p < 0.001), respectively. Smoothness of pedaling improved significantly from initial to terminal workloads (p < 0.001). Conclusions Improved pedaling kinematics at terminal workloads indicate that individuals with stroke demonstrate improved motor control with respect to the timing, sequencing, and activation of hemiparetic lower extremity musculature compared to lower workloads. Therapeutic prescription involving higher resistance may be necessary to sufficiently engage and activate the paretic lower extremity.

Excitatory and inhibitory innervation of the mouse orofacial motor nuclei: A stereological study.

PubMed

Faunes, Macarena; Oñate-Ponce, Alejandro; Fernández-Collemann, Sara; Henny, Pablo

2016-03-01

Neurons in the trigeminal (Mo5), facial (Mo7), ambiguus (Amb), and hypoglossal (Mo12) motor nuclei innervate jaw, facial, pharynx/larynx/esophagus, and tongue muscles, respectively. They are essential for movements subserving feeding, exploration of the environment, and social communication. These neurons are largely controlled by sensory afferents and premotor neurons of the reticular formation, where central pattern generator circuits controlling orofacial movements are located. To provide a description of the orofacial nuclei of the adult mouse and to ascertain the influence of excitatory and inhibitory afferents upon them, we used stereology to estimate the number of motoneurons as well as of varicosities immunopositive for glutamate (VGluT1+, VGluT2+) and GABA/glycine (known as VIAAT+ or VGAT+) vesicular transporters in the Mo5, Mo7, Amb, and Mo12. Mo5, Mo7, Amb, and Mo12 contain ∼1,000, ∼3,000, ∼600, and ∼1,700 cells, respectively. VGluT1+, VGluT2+, and VIAAT+ varicosities respectively represent: 28%, 41%, and 31% in Mo5; 2%, 49%, and 49% in Mo7; 12%, 42%, and 46% in Amb; and 4%, 54%, and 42% in Mo12. The Mo5 jaw-closing subdivision shows the highest VGluT1+ innervation. Noticeably, the VGluT2+ and VIAAT+ varicosity density in Mo7 is 5-fold higher than in Mo5 and 10-fold higher than in Amb and Mo12. The high density of terminals in Mo7 likely reflects the convergence and integration of numerous inputs to motoneurons subserving the wide range of complex behaviors to which this nucleus contributes. Also, somatic versus neuropil location of varicosities suggests that most of these afferents are integrated in the dendritic trees of Mo7 neurons. © 2015 Wiley Periodicals, Inc.

Astrocyte-Only Npc1 Reduces Neuronal Cholesterol and Triples Life Span of Npc1−/− Mice

PubMed Central

Zhang, Min; Strnatka, Diana; Donohue, Carolyn; Hallows, Jan; Vincent, Inez; Erickson, Robert P.

2009-01-01

Niemann-Pick type C (NPC) disease is an autosomal recessive, lethal neurodegenerative disorder. Although neurodegeneration of Purkinje cells in the mouse model (Npc1−/−) is thought to be autonomous, the basis of neuronal death in other regions of the brain remains elusive. We addressed this issue in vivo by using the glial fibrillary acidic protein (GFAP) promoter to direct astrocyte-specific, replacement expression of Npc1 in Npc1−/− mice. These mice showed enhanced survival, decreased neuronal storage of cholesterol associated with less accumulation of axonal spheroids, lower numbers of degenerated neurons and reactive astrocytes and restoration of myelin tracts. Their death was not associated with the usual terminal decline in weight, but instead with a loss of Purkinje cells and motor coordination. We conclude that neurodegeneration of Npc1−/− mice is greatly affected by the loss of fibrillary astrocyte function. PMID:18500759

Involvement of neurotrophin-3 (NT-3) in the functional elimination of synaptic contacts during neuromuscular development.

PubMed

Garcia, Neus; Santafé, Manel M; Tomàs, Marta; Lanuza, Maria A; Besalduch, Nuria; Tomàs, Josep

2010-04-05

Confocal immunohistochemistry shows that neurotrophin-3 (NT-3) and its receptor tropomyosin-related tyrosin kinase C (trkC) are present in both neonatal (P6) and adult (P45) mouse motor nerve terminals in neuromuscular junctions (NMJ) colocalized with several synaptic proteins. NT-3 incubation (1-3h, in the range 10-200ng/ml) does not change the size of the evoked and spontaneous endplate potentials at P45. However, NT-3 (1h, 100ng/ml) strongly potentiates evoked ACh release from the weak (70%) and the strong (50%) axonal inputs on dually innervated postnatal endplates (P6) but not in the most developed postnatal singly innervated synapses at P6. The present results indicate that NT-3 has a role in the developmental mechanism that eliminates redundant synapses though it cannot modulate synaptic transmission locally as the NMJ matures.

Full Length Human Mutant Huntingtin with a Stable Polyglutamine Repeat Can Elicit Progressive and Selective Neuropathogenesis in BACHD Mice

PubMed Central

Gray, Michelle; Shirasaki, Dyna I.; Cepeda, Carlos; Andre, Veronique M.; Wilburn, Brian; Lu, Xiao-Hong; Tao, Jifang; Yamazaki, Irene; Li, Shi-Hua; Sun, Yi E.; Li, Xiao-Jiang; Levine, Michael S.; William Yang, X

2008-01-01

To elucidate the pathogenic mechanisms in Huntington’s disease (HD) elicited by expression of full-length human mutant huntingtin (fl-mhtt), a Bacterial Artificial Chromosome (BAC)-mediated transgenic mouse model (BACHD) was developed expressing fl-mhtt with 97 glutamine repeats under the control of endogenous htt regulatory machinery on the BAC. BACHD mice exhibit progressive motor deficits, neuronal synaptic dysfunction, and late-onset selective neuropathology, which includes significant cortical and striatal atrophy and striatal dark neuron degeneration. Power analyses reveal the robustness of the behavioral and neuropathological phenotypes, suggesting BACHD as a suitable fl-mhtt mouse model for preclinical studies. Further analyses of BACHD mice provide additional insights into how mhtt may elicit neuropathogenesis. First, unlike prior fl-mhtt mouse models, BACHD mice reveal that the slowly progressive and selective pathogenic process in HD mouse brains can occur without early and diffuse nuclear accumulation of aggregated mhtt (i.e. as detected by immunostaining with the EM48 antibody). Instead, a relatively steady-state level of predominantly full-length mhtt and a small amount of mhtt N-terminal fragments are sufficient to elicit the disease process. Second, the polyglutamine repeat within fl-mhtt in BACHD mice is encoded by a mixed CAA-CAG repeat, which is stable in both the germline and somatic tissues including the cortex and striatum at the onset of neuropathology. Therefore, our results suggest that somatic repeat instability does not play a necessary role in selective neuropathogenesis in BACHD mice. In summary, the BACHD model constitutes a novel and robust in vivo paradigm for the investigation of HD pathogenesis and treatment. PMID:18550760

Silencing neuronal mutant androgen receptor in a mouse model of spinal and bulbar muscular atrophy.

PubMed

Sahashi, Kentaro; Katsuno, Masahisa; Hung, Gene; Adachi, Hiroaki; Kondo, Naohide; Nakatsuji, Hideaki; Tohnai, Genki; Iida, Madoka; Bennett, C Frank; Sobue, Gen

2015-11-01

Spinal and bulbar muscular atrophy (SBMA), an adult-onset neurodegenerative disease that affects males, results from a CAG triplet repeat/polyglutamine expansions in the androgen receptor (AR) gene. Patients develop progressive muscular weakness and atrophy, and no effective therapy is currently available. The tissue-specific pathogenesis, especially relative pathological contributions between degenerative motor neurons and muscles, remains inconclusive. Though peripheral pathology in skeletal muscle caused by toxic AR protein has been recently reported to play a pivotal role in the pathogenesis of SBMA using mouse models, the role of motor neuron degeneration in SBMA has not been rigorously investigated. Here, we exploited synthetic antisense oligonucleotides to inhibit the RNA levels of mutant AR in the central nervous system (CNS) and explore its therapeutic effects in our SBMA mouse model that harbors a mutant AR gene with 97 CAG expansions and characteristic SBMA-like neurogenic phenotypes. A single intracerebroventricular administration of the antisense oligonucleotides in the presymptomatic phase efficiently suppressed the mutant gene expression in the CNS, and delayed the onset and progression of motor dysfunction, improved body weight gain and survival with the amelioration of neuronal histopathology in motor units such as spinal motor neurons, neuromuscular junctions and skeletal muscle. These findings highlight the importance of the neurotoxicity of mutant AR protein in motor neurons as a therapeutic target. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Riluzole does not improve lifespan or motor function in three ALS mouse models.

PubMed

Hogg, Marion C; Halang, Luise; Woods, Ina; Coughlan, Karen S; Prehn, Jochen H M

2018-08-01

Riluzole is the most widespread therapeutic for treatment of the progressive degenerative disease amyotrophic lateral sclerosis (ALS). Riluzole gained FDA approval in 1995 before the development of ALS mouse models. We assessed riluzole in three transgenic ALS mouse models: the SOD1 G93A model, the TDP-43 A315T model, and the recently developed FUS (1-359) model. Age, sex and litter-matched mice were treated with riluzole (22 mg/kg) in drinking water or vehicle (DMSO) from symptom onset. Lifespan was assessed and motor function tests were carried out twice weekly to determine whether riluzole slowed disease progression. Riluzole treatment had no significant benefit on lifespan in any of the ALS mouse models tested. Riluzole had no significant impact on decline in motor performance in the FUS (1-359) and SOD1 G93A transgenic mice as assessed by Rotarod and stride length analysis. Riluzole is widely prescribed for ALS patients despite questions surrounding its efficacy. Our data suggest that if riluzole was identified as a therapeutic candidate today it would not progress past pre-clinical assessment. This raises questions about the standards used in pre-clinical assessment of therapeutic candidates for the treatment of ALS.

Automatic detection and quantitative analysis of cells in the mouse primary motor cortex

NASA Astrophysics Data System (ADS)

Meng, Yunlong; He, Yong; Wu, Jingpeng; Chen, Shangbin; Li, Anan; Gong, Hui

2014-09-01

Neuronal cells play very important role on metabolism regulation and mechanism control, so cell number is a fundamental determinant of brain function. Combined suitable cell-labeling approaches with recently proposed three-dimensional optical imaging techniques, whole mouse brain coronal sections can be acquired with 1-μm voxel resolution. We have developed a completely automatic pipeline to perform cell centroids detection, and provided three-dimensional quantitative information of cells in the primary motor cortex of C57BL/6 mouse. It involves four principal steps: i) preprocessing; ii) image binarization; iii) cell centroids extraction and contour segmentation; iv) laminar density estimation. Investigations on the presented method reveal promising detection accuracy in terms of recall and precision, with average recall rate 92.1% and average precision rate 86.2%. We also analyze laminar density distribution of cells from pial surface to corpus callosum from the output vectorizations of detected cell centroids in mouse primary motor cortex, and find significant cellular density distribution variations in different layers. This automatic cell centroids detection approach will be beneficial for fast cell-counting and accurate density estimation, as time-consuming and error-prone manual identification is avoided.

Isometric contractions of motor units and immunohistochemistry of mouse soleus muscle.

PubMed Central

Lewis, D M; Parry, D J; Rowlerson, A

1982-01-01

1. Isometric contractions of motor units, isolated functionally by ventral root splitting in vivo, were recorded from mouse soleus muscle. 2. Motor unit tensions varied over a narrow symmetrical range and averaged 4.7% of whole muscle tension, corresponding to twenty-one motor units per muscle. 3. There was considerable variation between muscles in isometric twitch times-to-peak and even greater variation for the motor units. The distribution of motor unit times-to-peak was apparently unimodal and could be fitted by a single normal population. A slightly better fit was, however, obtained with two normal populations, as suggested by the histochemistry. 4. Twitch time-to-peak decreased in proportion to axonal conduction velocity in individual animals. The whole population of motor units could be fitted by a linear relation between time-to-peak and the reciprocal of conduction time in the motor axon. Motor unit tension was also linearly related to the reciprocal of conduction time. 5. Histochemistry showed clear division between Type I and Type IIa fibres. Type I fibres reacted strongly with antibody against slow myosin of cat soleus muscle; Type IIa gave a reaction no stronger than the background. The division was as clear as in the cat or rat. Images Fig. 2 Plate 1 PMID:7050345

Protective effects of long-term lithium administration in a slowly progressive SMA mouse model.

PubMed

Biagioni, Francesca; Ferrucci, Michela; Ryskalin, Larisa; Fulceri, Federica; Lazzeri, Gloria; Calierno, Maria Teresa; Busceti, Carla L; Ruffoli, Riccardo; Fornai, Francesco

2017-12-01

In the present study we evaluated the long-term effects of lithium administration to a knock-out double transgenic mouse model (Smn-/-; SMN1A2G+/-; SMN2+/+) of Spinal Muscle Atrophy type III (SMA-III). This model is characterized by very low levels of the survival motor neuron protein, slow disease progression and motor neuron loss, which enables to detect disease-modifying effects at delayed time intervals. Lithium administration attenuates the decrease in motor activity and provides full protection from motor neuron loss occurring in SMA-III mice, throughout the disease course. In addition, lithium prevents motor neuron enlargement and motor neuron heterotopy and suppresses the occurrence of radial-like glial fibrillary acidic protein immunostaining in the ventral white matter of SMA-III mice. In SMA-III mice long-term lithium administration determines a dramatic increase of survival motor neuron protein levels in the spinal cord. These data demonstrate that long-term lithium administration during a long-lasting motor neuron disorder attenuates behavioural deficit and neuropathology. Since low level of survival motor neuron protein is bound to disease severity in SMA, the robust increase in protein level produced by lithium provides solid evidence which calls for further investigations considering lithium in the long-term treatment of spinal muscle atrophy.

Implementation of a manual for working with wobbler mice and criteria for discontinuation of the experiment.

PubMed

Ott, Bastian; Dahlke, Carolin; Meller, Karl; Napirei, Markus; Schmitt-John, Thomas; Brand-Saberi, Beate; Theiss, Carsten; Saberi, Darius

2015-07-01

Mouse breeding is of importance to a whole range of medical and biological research. There are many known mouse models for motor neuron diseases. However, it must be kept in mind that especially mouse models for amyotrophic lateral sclerosis develop severe symptoms causing intense stress. This article is designed to summarize conscientious work with the wobbler mouse, a model for the sporadic form of amyotrophic lateral sclerosis. This mouse model is characterized by a degeneration of α-motor-neurons leading to head tremor, loss of body weight and rapidly progressive paralysis. Although this mouse model has been known since 1956, there are no guidelines for breeding wobbler mice. Due to the lack of such guidelines the present study tries to close this gap and implements a manual for further studies. It includes the whole workflow in regard to wobbler mice from breeding and animal care taking, genotyping and phenotype analysis, but also gives some examples for the use of various neuronal tissues for histological investigation. Beside the progress in research a second aim should always be the enhancement of mouse welfare and reduction of stress for the laboratory animals. Copyright © 2015 Elsevier GmbH. All rights reserved.

The C-terminal periplasmic domain of MotB is responsible for load-dependent control of the number of stators of the bacterial flagellar motor.

PubMed

Castillo, David J; Nakamura, Shuichi; Morimoto, Yusuke V; Che, Yong-Suk; Kami-Ike, Nobunori; Kudo, Seishi; Minamino, Tohru; Namba, Keiichi

2013-01-01

The bacterial flagellar motor is made of a rotor and stators. In Salmonella it is thought that about a dozen MotA/B complexes are anchored to the peptidoglycan layer around the motor through the C-terminal peptidoglycan-binding domain of MotB to become active stators as well as proton channels. MotB consists of 309 residues, forming a single transmembrane helix (30-50), a stalk (51-100) and a C-terminal peptidoglycan-binding domain (101-309). Although the stalk is dispensable for torque generation by the motor, it is required for efficient motor performance. Residues 51 to 72 prevent premature proton leakage through the proton channel prior to stator assembly into the motor. However, the role of residues 72-100 remains unknown. Here, we analyzed the torque-speed relationship of the MotB(Δ72-100) motor. At a low speed near stall, this mutant motor produced torque at the wild-type level. Unlike the wild-type motor, however, torque dropped off drastically by slight decrease in external load and then showed a slow exponential decay over a wide range of load by its further reduction. Since it is known that the stator is a mechano-sensor and that the number of active stators changes in a load-dependent manner, we interpreted this unusual torque-speed relationship as anomaly in load-dependent control of the number of active stators. The results suggest that residues 72-100 of MotB is required for proper load-dependent control of the number of active stators around the rotor.

Intricate interplay between astrocytes and motor neurons in ALS

PubMed Central

Phatnani, Hemali P.; Guarnieri, Paolo; Friedman, Brad A.; Carrasco, Monica A.; Muratet, Michael; O’Keeffe, Sean; Nwakeze, Chiamaka; Pauli-Behn, Florencia; Newberry, Kimberly M.; Meadows, Sarah K.; Tapia, Juan Carlos; Myers, Richard M.; Maniatis, Tom

2013-01-01

ALS results from the selective and progressive degeneration of motor neurons. Although the underlying disease mechanisms remain unknown, glial cells have been implicated in ALS disease progression. Here, we examine the effects of glial cell/motor neuron interactions on gene expression using the hSOD1G93A (the G93A allele of the human superoxide dismutase gene) mouse model of ALS. We detect striking cell autonomous and nonautonomous changes in gene expression in cocultured motor neurons and glia, revealing that the two cell types profoundly affect each other. In addition, we found a remarkable concordance between the cell culture data and expression profiles of whole spinal cords and acutely isolated spinal cord cells during disease progression in the G93A mouse model, providing validation of the cell culture approach. Bioinformatics analyses identified changes in the expression of specific genes and signaling pathways that may contribute to motor neuron degeneration in ALS, among which are TGF-β signaling pathways. PMID:23388633

Transcription termination and RNA processing in the 3'-end spacer of mouse ribosomal RNA genes.

PubMed Central

Miwa, T; Kominami, R; Yoshikura, H; Sudo, K; Muramatsu, M

1987-01-01

The 3' termini of ribosomal RNA precursors from mouse FM3A cultured cells are mapped to eight sites within 625 bp downstream from the 3' terminus of 28 S rRNA. Three additional sites are mapped in liver RNA from C3H/He strain mice. Two of them, the sites at 570 bp and 625 bp are assumed to be termination sites in vivo, because they correspond to in vitro termination sites of RNA polymerase I, and 45 S RNAs having these 3' termini decay with kinetics distinct from others. The amount of 45 S RNA having the 3' terminus at other sites is variable among several mouse strains, despite their having the same DNA sequence in these regions. The ability to produce 3' termini in these sites seems to follow Mendel's law of inheritance. Therefore, we postulate that these nine sites are RNA processing sites which are controlled genetically. Images PMID:3031586

A novel mouse model carrying a human cytoplasmic dynein mutation shows motor behavior deficits consistent with Charcot-Marie-Tooth type 2O disease.

PubMed

Sabblah, Thywill T; Nandini, Swaran; Ledray, Aaron P; Pasos, Julio; Calderon, Jami L Conley; Love, Rachal; King, Linda E; King, Stephen J

2018-01-29

Charcot-Marie-Tooth disease (CMT) is a peripheral neuromuscular disorder in which axonal degeneration causes progressive loss of motor and sensory nerve function. The loss of motor nerve function leads to distal muscle weakness and atrophy, resulting in gait problems and difficulties with walking, running, and balance. A mutation in the cytoplasmic dynein heavy chain (DHC) gene was discovered to cause an autosomal dominant form of the disease designated Charcot-Marie-Tooth type 2 O disease (CMT2O) in 2011. The mutation is a single amino acid change of histidine into arginine at amino acid 306 (H306R) in DHC. In order to understand the onset and progression of CMT2, we generated a knock-in mouse carrying the corresponding CMT2O mutation (H304R/+). We examined H304R/+ mouse cohorts in a 12-month longitudinal study of grip strength, tail suspension, and rotarod assays. H304R/+ mice displayed distal muscle weakness and loss of motor coordination phenotypes consistent with those of individuals with CMT2. Analysis of the gastrocnemius of H304R/+ male mice showed prominent defects in neuromuscular junction (NMJ) morphology including reduced size, branching, and complexity. Based on these results, the H304R/+ mouse will be an important model for uncovering functions of dynein in complex organisms, especially related to CMT onset and progression.

Enhanced striatal dopamine transmission and motor performance with LRRK2 overexpression in mice is eliminated by familial Parkinson's disease mutation G2019S.

PubMed

Li, Xianting; Patel, Jyoti C; Wang, Jing; Avshalumov, Marat V; Nicholson, Charles; Buxbaum, Joseph D; Elder, Gregory A; Rice, Margaret E; Yue, Zhenyu

2010-02-03

PARK8/LRRK2 (leucine-rich repeat kinase 2) was recently identified as a causative gene for autosomal dominant Parkinson's disease (PD), with LRRK2 mutation G2019S linked to the most frequent familial form of PD. Emerging in vitro evidence indicates that aberrant enzymatic activity of LRRK2 protein carrying this mutation can cause neurotoxicity. However, the physiological and pathophysiological functions of LRRK2 in vivo remain elusive. Here we characterize two bacterial artificial chromosome (BAC) transgenic mouse strains overexpressing LRRK2 wild-type (Wt) or mutant G2019S. Transgenic LRRK2-Wt mice had elevated striatal dopamine (DA) release with unaltered DA uptake or tissue content. Consistent with this result, LRRK2-Wt mice were hyperactive and showed enhanced performance in motor function tests. These results suggest a role for LRRK2 in striatal DA transmission and the consequent motor function. In contrast, LRRK2-G2019S mice showed an age-dependent decrease in striatal DA content, as well as decreased striatal DA release and uptake. Despite increased brain kinase activity, LRRK2-G2019S overexpression was not associated with loss of DAergic neurons in substantia nigra or degeneration of nigrostriatal terminals at 12 months. Our results thus reveal a pivotal role for LRRK2 in regulating striatal DA transmission and consequent control of motor function. The PD-associated mutation G2019S may exert pathogenic effects by impairing these functions of LRRK2. Our LRRK2 BAC transgenic mice, therefore, could provide a useful model for understanding early PD pathological events.

Neuroprotective Effect of Non-viral Gene Therapy Treatment Based on Tetanus Toxin C-fragment in a Severe Mouse Model of Spinal Muscular Atrophy.

PubMed

Oliván, Sara; Calvo, Ana C; Rando, Amaya; Herrando-Grabulosa, Mireia; Manzano, Raquel; Zaragoza, Pilar; Tizzano, Eduardo F; Aquilera, Jose; Osta, Rosario

2016-01-01

Spinal muscular atrophy (SMA) is a hereditary childhood disease that causes paralysis and progressive degeneration of skeletal muscles and spinal motor neurons. SMA is associated with reduced levels of full-length Survival of Motor Neuron (SMN) protein, due to mutations in the Survival of Motor Neuron 1 gene. Nowadays there are no effective therapies available to treat patients with SMA, so our aim was to test whether the non-toxic carboxy-terminal fragment of tetanus toxin heavy chain (TTC), which exhibits neurotrophic properties, might have a therapeutic role or benefit in SMA. In this manuscript, we have demonstrated that TTC enhance the SMN expression in motor neurons "in vitro" and evaluated the effect of intramuscular injection of TTC-encoding plasmid in the spinal cord and the skeletal muscle of SMNdelta7 mice. For this purpose, we studied the weight and the survival time, as well as, the survival and cell death pathways and muscular atrophy. Our results showed that TTC treatment reduced the expression of autophagy markers (Becn1, Atg5, Lc3, and p62) and pro-apoptotic genes such as Bax and Casp3 in spinal cord. In skeletal muscle, TTC was able to downregulate the expression of the main marker of autophagy, Lc3, to wild-type levels and the expression of the apoptosis effector protein, Casp3. Regarding the genes related to muscular atrophy (Ankrd1, Calm1, Col19a1, Fbox32, Mt2, Myod1, NogoA, Pax7, Rrad, and Sln), TTC suggest a compensatory effect for muscle damage response, diminished oxidative stress and modulated calcium homeostasis. These preliminary findings suggest the need for further experiments to depth study the effect of TTC in SMA disease.

Spurious-Mode Control of Same-Phase Drive-Type Ultrasonic Motor

NASA Astrophysics Data System (ADS)

Aoyagi, Manabu; Watanabe, Hiroyuki; Tomikawa, Yoshiro; Takano, Takehiro

2002-05-01

A same-phase drive-type ultrasonic motor requires a single power source for its operation. In particular, self-oscillation driving is useful for driving a small ultrasonic motor. This type of ultrasonic motor has a spurious mode close to the operation frequency on its stator vibrator. The spurious vibration mode affects the oscillation frequency of a self-oscillation drive circuit. Hence the spurious vibration mode should be restrained or moved away from the neighborhood of the operation frequency. In this paper, we report that an inductor connected at an electrical control terminal provided on standby electrodes for the reverse rotation operation controls only the spurious vibration mode. The effect of an inductor connected at the control terminal was clarified by the simulation of an equivalent circuit and some experiments.

29. INTERIOR VIEW OF FERRY MOUSE, SOUTH CENTRAL BUILDING, FIRST ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

29. INTERIOR VIEW OF FERRY MOUSE, SOUTH CENTRAL BUILDING, FIRST LEVEL, LOOKING WEST, FERRYMEN'S QUARTERS - Central Railroad of New Jersey, Jersey City Ferry Terminal, Johnson Avenue at Hudson River, Jersey City, Hudson County, NJ

A lightweight electronically commutated dc motor for electric passenger vehicles

NASA Technical Reports Server (NTRS)

Echolds, E. F.; Walla, P. S.

1982-01-01

A functional model breadboard converter and a rare-earth-cobalt, permanent magnet motor; as well as an engineering model converter and PM motor suitable for vehicle installations were developed and tested. The converter and motor achieved an 88% peak efficiency, a maximum output of 26 kW at 26,000 rpm, and a continuous rating of 15 kW. The system also generated power to the source during braking, with a demonstrated peak power available at the converter terminals of approximately 26 kW at 88% efficiency. Major conclusions include: (1) the SAE J227a(D) driving cycle efficiency for the converter/motor is 86% to 88% when energy available for recovery at the converter terminals is included; (2) the converter initial cost is approximately five times that of the permanent magnet motor, but can be reduced by means of LSI logic and integrated liquid cooled semiconductor packages; and (3) an electronically commutated motor with a liquid cooled converter will operate reliably without service or maintenance for the life of a passenger vehicle.

A lightweight electronically commutated dc motor for electric passenger vehicles

NASA Astrophysics Data System (ADS)

Echolds, E. F.; Walla, P. S.

1982-09-01

A functional model breadboard converter and a rare-earth-cobalt, permanent magnet motor; as well as an engineering model converter and PM motor suitable for vehicle installations were developed and tested. The converter and motor achieved an 88% peak efficiency, a maximum output of 26 kW at 26,000 rpm, and a continuous rating of 15 kW. The system also generated power to the source during braking, with a demonstrated peak power available at the converter terminals of approximately 26 kW at 88% efficiency. Major conclusions include: (1) the SAE J227a(D) driving cycle efficiency for the converter/motor is 86% to 88% when energy available for recovery at the converter terminals is included; (2) the converter initial cost is approximately five times that of the permanent magnet motor, but can be reduced by means of LSI logic and integrated liquid cooled semiconductor packages; and (3) an electronically commutated motor with a liquid cooled converter will operate reliably without service or maintenance for the life of a passenger vehicle.

Pyramidal tract stimulation restores normal corticospinal tract connections and visuomotor skill after early postnatal motor cortex activity blockade

PubMed Central

Salimi, I; Friel, KM; Martin, JH

2008-01-01

Motor development depends on forming specific connections between the corticospinal tract (CST) and the spinal cord. Blocking CST activity in kittens during the critical period for establishing connections with spinal motor circuits results in permanent impairments in connectivity and function. The changes in connections are consistent with the hypothesis that the inactive tract is less competitive in developing spinal connections than the active tract. In this study we tested the competition hypothesis by determining if activating CST axons, after prior silencing during the critical period, abrogated development of aberrant corticospinal connections and motor impairments. In kittens, we inactivated motor cortex by muscimol infusion between postnatal weeks 5-7. We next electrically stimulated CST axons in the medullary pyramid 2.5 hours daily, between weeks 7-10. In controls (n=3), CST terminations were densest within the contralateral deeper, premotor, spinal layers. After prior inactivation (n=3), CST terminations were densest within the dorsal, somatic sensory, layers. There were more ipsilateral terminations from the active tract. During visually guided locomotion, there was a movement endpoint impairment. Stimulation after inactivation (n=6) resulted in significantly fewer terminations in the sensory layers and more in the premotor layers, and fewer ipsilateral connections from active cortex. Chronic stimulation reduced the current threshold for evoking contralateral movements by pyramidal stimulation, suggesting strengthening of connections. Importantly, stimulation significantly improved stepping accuracy. These findings show the importance of activity-dependent processes in specifying CST connections. They also provide a strategy for harnessing activity to rescue CST axons at risk of developing aberrant connections after CNS injury. PMID:18632946

Bilateral Activity-Dependent Interactions in the Developing Corticospinal System

PubMed Central

Friel, Kathleen M.; Martin, John H.

2009-01-01

Activity-dependent competition between the corticospinal (CS) systems in each hemisphere drives postnatal development of motor skills and stable CS tract connections with contralateral spinal motor circuits. Unilateral restriction of motor cortex (M1) activity during an early postnatal critical period impairs contralateral visually guided movements later in development and in maturity. Silenced M1 develops aberrant connections with the contralateral spinal cord whereas the initially active M1, in the other hemisphere, develops bilateral connections. In this study, we determined whether the aberrant pattern of CS tract terminations and motor impairments produced by early postnatal M1 activity restriction could be abrogated by reducing activity-dependent synaptic competition from the initially active M1 later in development. We first inactivated M1 unilaterally between postnatal weeks 5–7. We next inactivated M1 on the other side from weeks 7–11 (alternate inactivation), to reduce the competitive advantage that this side may have over the initially inactivated side. Alternate inactivation redirected aberrant contralateral CS tract terminations from the initially silenced M1 to their normal spinal territories and reduced the density of aberrant ipsilateral terminations from the initially active side. Normal movement endpoint control during visually guided locomotion was fully restored. This reorganization of CS terminals reveals an unsuspected late plasticity after the critical period for establishing the pattern of CS terminations in the spinal cord. Our findings show that robust bilateral interactions between the developing CS systems on each side are important for achieving balance between contralateral and ipsilateral CS tract connections and visuomotor control. PMID:17928450

Induction of parkinsonism-related proteins in the spinal motor neurons of transgenic mouse carrying a mutant SOD1 gene.

PubMed

Morimoto, Nobutoshi; Nagai, Makiko; Miyazaki, Kazunori; Ohta, Yasuyuki; Kurata, Tomoko; Takehisa, Yasushi; Ikeda, Yoshio; Matsuura, Tohru; Asanuma, Masato; Abe, Koji

2010-06-01

Amyotrophic lateral sclerosis is a progressive and fatal disease caused by selective death of motor neurons, and a number of these patients carry mutations in the superoxide dismutase 1 (SOD1) gene involved in ameliorating oxidative stress. Recent studies indicate that oxidative stress and disruption of mitochondrial homeostasis is a common mechanism for motor neuron degeneration in amyotrophic lateral sclerosis and the loss of midbrain dopamine neurons in Parkinson's disease. Therefore, the present study investigated the presence and alterations of familial Parkinson's disease-related proteins, PINK1 and DJ-1, in spinal motor neurons of G93ASOD1 transgenic mouse model of amyotrophic lateral sclerosis. Following onset of disease, PINK1 and DJ-1 protein expression increased in the spinal motor neurons. The activated form of p53 also increased and translocated to the nuclei of spinal motor neurons, followed by increased expression of p53-activated gene 608 (PAG608). This is the first report demonstrating that increased expression of PAG608 correlates with activation of phosphorylated p53 in spinal motor neurons of an amyotrophic lateral sclerosis model. These results provide further evidence of the profound correlations between spinal motor neurons of amyotrophic lateral sclerosis and parkinsonism-related proteins.

Role of VGF-derived carboxy-terminal peptides in energy balance and reproduction: analysis of "humanized" knockin mice expressing full-length or truncated VGF.

PubMed

Sadahiro, Masato; Erickson, Connor; Lin, Wei-Jye; Shin, Andrew C; Razzoli, Maria; Jiang, Cheng; Fargali, Samira; Gurney, Allison; Kelley, Kevin A; Buettner, Christoph; Bartolomucci, Alessandro; Salton, Stephen R

2015-05-01

Targeted deletion of VGF, a secreted neuronal and endocrine peptide precursor, produces lean, hypermetabolic, and infertile mice that are resistant to diet-, lesion-, and genetically-induced obesity and diabetes. Previous studies suggest that VGF controls energy expenditure (EE), fat storage, and lipolysis, whereas VGF C-terminal peptides also regulate reproductive behavior and glucose homeostasis. To assess the functional equivalence of human VGF(1-615) (hVGF) and mouse VGF(1-617) (mVGF), and to elucidate the function of the VGF C-terminal region in the regulation of energy balance and susceptibility to obesity, we generated humanized VGF knockin mouse models expressing full-length hVGF or a C-terminally deleted human VGF(1-524) (hSNP), encoded by a single nucleotide polymorphism (rs35400704). We show that homozygous male and female hVGF and hSNP mice are fertile. hVGF female mice had significantly increased body weight compared with wild-type mice, whereas hSNP mice have reduced adiposity, increased activity- and nonactivity-related EE, and improved glucose tolerance, indicating that VGF C-terminal peptides are not required for reproductive function, but 1 or more specific VGF C-terminal peptides are likely to be critical regulators of EE. Taken together, our results suggest that human and mouse VGF proteins are largely functionally conserved but that species-specific differences in VGF peptide function, perhaps a result of known differences in receptor binding affinity, likely alter the metabolic phenotype of hVGF compared with mVGF mice, and in hSNP mice in which several C-terminal VGF peptides are ablated, result in significantly increased activity- and nonactivity-related EE.

Role of VGF-Derived Carboxy-Terminal Peptides in Energy Balance and Reproduction: Analysis of “Humanized” Knockin Mice Expressing Full-Length or Truncated VGF

PubMed Central

Sadahiro, Masato; Erickson, Connor; Lin, Wei-Jye; Shin, Andrew C.; Razzoli, Maria; Jiang, Cheng; Fargali, Samira; Gurney, Allison; Kelley, Kevin A.; Buettner, Christoph

2015-01-01

Targeted deletion of VGF, a secreted neuronal and endocrine peptide precursor, produces lean, hypermetabolic, and infertile mice that are resistant to diet-, lesion-, and genetically-induced obesity and diabetes. Previous studies suggest that VGF controls energy expenditure (EE), fat storage, and lipolysis, whereas VGF C-terminal peptides also regulate reproductive behavior and glucose homeostasis. To assess the functional equivalence of human VGF1–615 (hVGF) and mouse VGF1–617 (mVGF), and to elucidate the function of the VGF C-terminal region in the regulation of energy balance and susceptibility to obesity, we generated humanized VGF knockin mouse models expressing full-length hVGF or a C-terminally deleted human VGF1–524 (hSNP), encoded by a single nucleotide polymorphism (rs35400704). We show that homozygous male and female hVGF and hSNP mice are fertile. hVGF female mice had significantly increased body weight compared with wild-type mice, whereas hSNP mice have reduced adiposity, increased activity- and nonactivity-related EE, and improved glucose tolerance, indicating that VGF C-terminal peptides are not required for reproductive function, but 1 or more specific VGF C-terminal peptides are likely to be critical regulators of EE. Taken together, our results suggest that human and mouse VGF proteins are largely functionally conserved but that species-specific differences in VGF peptide function, perhaps a result of known differences in receptor binding affinity, likely alter the metabolic phenotype of hVGF compared with mVGF mice, and in hSNP mice in which several C-terminal VGF peptides are ablated, result in significantly increased activity- and nonactivity-related EE. PMID:25675362

Development of a terminally sterilised decellularised dermis.

PubMed

Hogg, P; Rooney, P; Leow-Dyke, S; Brown, C; Ingham, E; Kearney, J N

2015-09-01

Many of the decellularised dermis products on the market at present are aspectically produced. NHS Blood and Transplant Tissue Services have developed a method of producing a dCELL human dermis which has been terminally sterilised by gamma irradiation. The terminally sterilised decellularised dermis was compared with cellular tissue and examined for histology, residual DNA content, biomechanical and biochemical properties, in vitro cytotoxicity and in vivo implantation in a mouse model. No alterations in morphology as viewed by light microscopy were observed and DNA removal was 99%. There were no significant changes in ultimate tensile stress or evidence for collagen denaturation or cytotoxicity. The in vivo studies did not indicate any adverse tissue reactions in the mouse model and demonstrated incorporation of dCELL human dermis into the host. Decellularisation, followed by terminal sterilisation with gamma irradiation, is an appropriate method to produce a human dermis allograft material suitable for transplantation.

Glutamic Acid as a Precursor to N-Terminal Pyroglutamic Acid in Mouse Plasmacytoma Protein

PubMed Central

Twardzik, Daniel R.; Peterkofsky, Alan

1972-01-01

Cell suspensions derived from a mouse plasmacytoma (RPC-20) that secretes an immunoglobulin light chain containing N-terminal pyroglutamic acid can synthesize protein in vitro. Chromatographic examination of an enzymatic digest of protein labeled with glutamic acid shows only labeled glutamic acid and pyroglutamic acid; hydrolysis of protein from cells labeled with glutamine, however, yields substantial amounts of glutamic acid in addition to glutamine and pyroglutamic acid. The absence of glutamine synthetase and presence of glutaminase in plasmacytoma homogenates is consistent with these findings. These data indicate that N-terminal pyroglutamic acid can be derived from glutamic acid without prior conversion of glutamic acid to glutamine. Since free or bound forms of glutamine cyclize nonezymatically to pyroglutamate with ease, while glutamic acid does not, the data suggest that N-terminal pyroglutamic acid formation from glutamic acid is enzymatic rather than spontaneous. Images PMID:4400295

Identification of a human synaptotagmin-1 mutation that perturbs synaptic vesicle cycling

PubMed Central

Baker, Kate; Gordon, Sarah L.; Grozeva, Detelina; van Kogelenberg, Margriet; Roberts, Nicola Y.; Pike, Michael; Blair, Edward; Hurles, Matthew E.; Chong, W. Kling; Baldeweg, Torsten; Kurian, Manju A.; Boyd, Stewart G.; Cousin, Michael A.; Raymond, F. Lucy

2015-01-01

Synaptotagmin-1 (SYT1) is a calcium-binding synaptic vesicle protein that is required for both exocytosis and endocytosis. Here, we describe a human condition associated with a rare variant in SYT1. The individual harboring this variant presented with an early onset dyskinetic movement disorder, severe motor delay, and profound cognitive impairment. Structural MRI was normal, but EEG showed extensive neurophysiological disturbances that included the unusual features of low-frequency oscillatory bursts and enhanced paired-pulse depression of visual evoked potentials. Trio analysis of whole-exome sequence identified a de novo SYT1 missense variant (I368T). Expression of rat SYT1 containing the equivalent human variant in WT mouse primary hippocampal cultures revealed that the mutant form of SYT1 correctly localizes to nerve terminals and is expressed at levels that are approximately equal to levels of endogenous WT protein. The presence of the mutant SYT1 slowed synaptic vesicle fusion kinetics, a finding that agrees with the previously demonstrated role for I368 in calcium-dependent membrane penetration. Expression of the I368T variant also altered the kinetics of synaptic vesicle endocytosis. Together, the clinical features, electrophysiological phenotype, and in vitro neuronal phenotype associated with this dominant negative SYT1 mutation highlight presynaptic mechanisms that mediate human motor control and cognitive development. PMID:25705886

GDNF-expressing macrophages mitigate loss of dopamine neurons and improve Parkinsonian symptoms in MitoPark mice.

PubMed

Chen, Cang; Li, Xiuhua; Ge, Guo; Liu, Jingwei; Biju, K C; Laing, Suzette D; Qian, Yusheng; Ballard, Cori; He, Zhixu; Masliah, Eliezer; Clark, Robert A; O'Connor, Jason C; Li, Senlin

2018-04-03

Glial cell line-derived neurotrophic factor (GDNF) is the most potent neuroprotective agent tested in cellular and animal models of Parkinson's disease (PD). However, CNS delivery of GDNF is restricted by the blood-brain barrier (BBB). Using total body irradiation as transplant preconditioning, we previously reported that hematopoietic stem cell (HSC) transplantation (HSCT)-based macrophage-mediated gene therapy could deliver GDNF to the brain to prevent degeneration of nigrostriatal dopamine (DA) neurons in an acute murine neurotoxicity model. Here, we validate this therapeutic approach in a chronic progressive PD model - the MitoPark mouse, with head shielding to avoid inducing neuroinflammation and compromising BBB integrity. Bone marrow HSCs were transduced ex vivo with a lentiviral vector expressing macrophage promoter-driven GDNF and transplanted into MitoPark mice exhibiting well developed PD-like impairments. Transgene-expressing macrophages infiltrated the midbrains of MitoPark mice, but not normal littermates, and delivered GDNF locally. Macrophage GDNF delivery markedly improved both motor and non-motor symptoms, and dramatically mitigated the loss of both DA neurons in the substantia nigra and tyrosine hydroxylase-positive axonal terminals in the striatum. Our data support further development of this HSCT-based macrophage-mediated GDNF delivery approach in order to address the unmet need for a disease-modifying therapy for PD.

Abnormal nuclear envelope in the cerebellar Purkinje cells and impaired motor learning in DYT11 myoclonus-dystonia mouse models

PubMed Central

Yokoi, Fumiaki; Dang, Mai T.; Yang, Guang; Li, JinDong; Doroodchi, Atbin; Zhou, Tong; Li, Yuqing

2011-01-01

Myoclonus-dystonia (M-D) is a movement disorder characterized by myoclonic jerks with dystonia. DYT11 M-D is caused by mutations in SGCE which codes for ε-sarcoglycan. SGCE is maternally imprinted and paternally expressed. Abnormal nuclear envelope has been reported in mouse models of DYT1 generalized torsion dystonia. However, it is not known whether similar alterations occur in DYT11 M-D. We developed a mouse model of DYT11 M-D using paternally-inherited Sgce heterozygous knockout (Sgce KO) mice and reported that they had myoclonus and motor coordination and learning deficits in the beam-walking test. However, the specific brain regions that contribute to these phenotypes have not been identified. Since ε-sarcoglycan is highly expressed in the cerebellar Purkinje cells, here we examined the nuclear envelope in these cells using a transmission electron microscope and found that they are abnormal in Sgce KO mice. Our results put DYT11 M-D in a growing family of nuclear envelopathies. To analyze the effect of loss of ε-sarcoglycan function in the cerebellar Purkinje cells, we produced paternally-inherited cerebellar Purkinje cell-specific Sgce conditional knockout (Sgce pKO) mice. Sgce pKO mice showed motor learning deficits, while they did not show abnormal nuclear envelope in the cerebellar Purkinje cells, robust motor deficits, or myoclonus. The results suggest that ε-sarcoglycan in the cerebellar Purkinje cells contributes to the motor learning, while loss of ε-sarcoglycan in other brain regions may contribute to nuclear envelope abnormality, myoclonus and motor coordination deficits. PMID:22040906

Sema4D/CD100 deficiency leads to superior performance in mouse motor behavior.

PubMed

Yukawa, Kazunori; Tanaka, Tetsuji; Takeuchi, Noriko; Iso, Hiroyuki; Li, Li; Kohsaka, Akira; Waki, Hidefumi; Miyajima, Masayasu; Maeda, Masanobu; Kikutani, Hitoshi; Kumanogoh, Atsushi

2009-05-01

Sema4D/CD100 is a type of class 4 semaphorin, exhibiting crucial roles in growth cone guidance in developing neurons. Sema4D is widely expressed throughout the central nervous system in embryonic mouse brain, and is selectively localized to oligodendrocytes and myelin in the postnatal brain. However, direct evidence of the actual involvement of Sema4D in the neuronal network development crucial for neurobehavioral performance is still lacking. The present study therefore examined whether Sema4D deficiency leads to abnormal behavioral development. Both wild-type and Sema4D-deficient mice were subjected to behavioral analyses including open-field, adhesive tape removal, rotarod tests and a water maze task. Open-field tests revealed increased locomotor activity in Sema4D-deficient mice with less percentage of time spent in the center of the field. In both the adhesive tape removal and rotarod tests, which examine motor coordination and balance, Sema4D-deficient mice showed significantly superior performance, suggesting facilitated motor behavior. Both Sema4D-deficient and wild-type mice successfully learnt the water maze task, locating a hidden escape platform, and also showed precise memory for the platform position in probe tests. However, the swimming speed of Sema4D-deficient mice was significantly faster than that of wild-type mice, providing further evidence of their accelerated motor behavior. Our mouse behavioral analyses revealed enhanced motor activity in Sema4D-deficient mice, suggesting the crucial involvement of Sema4D in the neurodevelopmental processes of the central structures mediating motor behavior in mice.

IGF-1 delivery to CNS attenuates motor neuron cell death but does not improve motor function in type III SMA mice.

PubMed

Tsai, Li-Kai; Chen, Yi-Chun; Cheng, Wei-Cheng; Ting, Chen-Hung; Dodge, James C; Hwu, Wuh-Liang; Cheng, Seng H; Passini, Marco A

2012-01-01

The efficacy of administering a recombinant adeno-associated virus (AAV) vector encoding human IGF-1 (AAV2/1-hIGF-1) into the deep cerebellar nucleus (DCN) of a type III SMA mouse model was evaluated. High levels of IGF-1 transcripts and protein were detected in the spinal cord at 2 months post-injection demonstrating that axonal connections between the cerebellum and spinal cord were able to act as conduits for the viral vector and protein to the spinal cord. Mice treated with AAV2/1-hIGF-1 and analyzed 8 months later showed changes in endogenous Bax and Bcl-xl levels in spinal cord motor neurons that were consistent with IGF-1-mediated anti-apoptotic effects on motor neurons. However, although AAV2/1-hIGF-1 treatment reduced the extent of motor neuron cell death, the majority of rescued motor neurons were non-functional, as they lacked axons that innervated the muscles. Furthermore, treated SMA mice exhibited abnormal muscle fibers, aberrant neuromuscular junction structure, and impaired performance on motor function tests. These data indicate that although CNS-directed expression of IGF-1 could reduce motor neuron cell death, this did not translate to improvements in motor function in an adult mouse model of type III SMA. Copyright © 2011 Elsevier Inc. All rights reserved.

Regulation of Survival Motor Neuron Protein by the Nuclear Factor-Kappa B Pathway in Mouse Spinal Cord Motoneurons.

PubMed

Arumugam, Saravanan; Mincheva-Tasheva, Stefka; Periyakaruppiah, Ambika; de la Fuente, Sandra; Soler, Rosa M; Garcera, Ana

2018-06-01

Survival motor neuron (SMN) protein deficiency causes the genetic neuromuscular disorder spinal muscular atrophy (SMA), characterized by spinal cord motoneuron degeneration. Since SMN protein level is critical to disease onset and severity, analysis of the mechanisms involved in SMN stability is one of the central goals of SMA research. Here, we describe the role of several members of the NF-κB pathway in regulating SMN in motoneurons. NF-κB is one of the main regulators of motoneuron survival and pharmacological inhibition of NF-κB pathway activity also induces mouse survival motor neuron (Smn) protein decrease. Using a lentiviral-based shRNA approach to reduce the expression of several members of NF-κB pathway, we observed that IKK and RelA knockdown caused Smn reduction in mouse-cultured motoneurons whereas IKK or RelB knockdown did not. Moreover, isolated motoneurons obtained from the severe SMA mouse model showed reduced protein levels of several NF-κB members and RelA phosphorylation. We describe the alteration of NF-κB pathway in SMA cells. In the context of recent studies suggesting regulation of altered intracellular pathways as a future pharmacological treatment of SMA, we propose the NF-κB pathway as a candidate in this new therapeutic approach.

Ex vivo delivery of GDNF maintains motor function and prevents neuronal loss in a transgenic mouse model of Huntington's disease.

PubMed

Ebert, Allison D; Barber, Amelia E; Heins, Brittany M; Svendsen, Clive N

2010-07-01

Huntington's disease (HD) is an autosomal dominant disorder caused by expansion of polyglutamine repeats in the huntingtin gene leading to loss of striatal and cortical neurons followed by deficits in cognition and choreic movements. Growth factor delivery to the brain has shown promise in various models of neurodegenerative diseases, including HD, by reducing neuronal death and thus limiting motor impairment. Here we used mouse neural progenitor cells (mNPCs) as growth factor delivery vehicles in the N171-82Q transgenic mouse model of HD. mNPCs derived from the developing mouse striatum were isolated and infected with lentivirus expressing either glial cell line-derived neurotrophic factor (GDNF) or green fluorescent protein (GFP). Next, mNPCs(GDNF) or mNPCs(GFP) were transplanted bilaterally into the striatum of pre-symptomatic N171-82Q mice. We found that mNPCs(GDNF), but not mNPCs(GFP), maintained rotarod function and increased striatal neuron survival out to 3months post-transplantation. Importantly, histological analysis showed GDNF expression through the duration of the experiment. Our data show that mNPCs(GDNF) can survive transplantation, secrete GDNF for several weeks and are able to maintain motor function in this model of HD. Copyright 2010 Elsevier Inc. All rights reserved.

MPP+-Lesioned Mice: an Experimental Model of Motor, Emotional, Memory/Learning, and Striatal Neurochemical Dysfunctions.

PubMed

Cunha, Mauricio P; Pazini, Francis L; Lieberknecht, Vicente; Budni, Josiane; Oliveira, Ágatha; Rosa, Júlia M; Mancini, Gianni; Mazzardo, Leidiane; Colla, André R; Leite, Marina C; Santos, Adair R S; Martins, Daniel F; de Bem, Andreza F; Gonçalves, Carlos Alberto S; Farina, Marcelo; Rodrigues, Ana Lúcia S

2017-10-01

The neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induces motor and nonmotor dysfunctions resembling Parkinson's disease (PD); however, studies investigating the effects of 1-methyl-4-phenylpyridinium (MPP + ), an active oxidative product of MPTP, are scarce. This study investigated the behavioral and striatal neurochemical changes (related to oxidative damage, glial markers, and neurotrophic factors) 24 h after intracerebroventricular administration of MPP + (1.8-18 μg/mouse) in C57BL6 mice. MPP + administration at high dose (18 μg/mouse) altered motor parameters, since it increased the latency to leave the first quadrant and reduced crossing, rearing, and grooming responses in the open-field test and decreased rotarod latency time. MPP + administration at low dose (1.8 μg/mouse) caused specific nonmotor dysfunctions as it produced a depressive-like effect in the forced swim test and tail suspension test, loss of motivational and self-care behavior in the splash test, anxiety-like effect in the elevated plus maze test, and short-term memory deficit in the step-down inhibitory avoidance task, without altering ambulation. MPP + at doses of 1.8-18 μg/mouse increased tyrosine hydroxylase (TH) immunocontent and at 18 μg/mouse increased α-synuclein and decreased parkin immunocontent. The astrocytic calcium-binding protein S100B and glial fibrillary acidic protein (GFAP)/S100B ratio was decreased following MPP + administration (18 μg/mouse). At this highest dose, MPP + increased the ionized calcium-binding adapter molecule 1 (Iba-1) immunocontent, suggesting microglial activation. Also, MPP + at a dose of 18 μg/mouse increased thiobarbituric acid reactive substances (TBARS) and glutathione (GSH) levels and increased glutathione peroxidase (GPx) and hemeoxygenase-1 (HO-1) immunocontent, suggesting a significant role for oxidative stress in the MPP + -induced striatal damage. MPP + (18 μg/mouse) also increased striatal fibroblast growth factor 2 (FGF-2) and brain-derived neurotrophic factor (BDNF) levels. Moreover, MPP + decreased tropomyosin receptor kinase B (TrkB) immunocontent. Finally, MPP + (1.8-18 μg/mouse) increased serum corticosterone levels and did not alter acetylcholinesterase (AChE) activity in the striatum but increased it in cerebral cortex and hippocampus. Collectively, these results indicate that MPP + administration at low doses may be used as a model of emotional and memory/learning behavioral deficit related to PD and that MPP + administration at high dose could be useful for analysis of striatal dysfunctions associated with motor deficits in PD.

Compensatory Limb Use and Behavioral Assessment of Motor Skill Learning Following Sensorimotor Cortex Injury in a Mouse Model of Ischemic Stroke

PubMed Central

Kerr, Abigail L.; Tennant, Kelly A.

2014-01-01

Mouse models have become increasingly popular in the field of behavioral neuroscience, and specifically in studies of experimental stroke. As models advance, it is important to develop sensitive behavioral measures specific to the mouse. The present protocol describes a skilled motor task for use in mouse models of stroke. The Pasta Matrix Reaching Task functions as a versatile and sensitive behavioral assay that permits experimenters to collect accurate outcome data and manipulate limb use to mimic human clinical phenomena including compensatory strategies (i.e., learned non-use) and focused rehabilitative training. When combined with neuroanatomical tools, this task also permits researchers to explore the mechanisms that support behavioral recovery of function (or lack thereof) following stroke. The task is both simple and affordable to set up and conduct, offering a variety of training and testing options for numerous research questions concerning functional outcome following injury. Though the task has been applied to mouse models of stroke, it may also be beneficial in studies of functional outcome in other upper extremity injury models. PMID:25045916

Overexpression of mutant HSP27 causes axonal neuropathy in mice.

PubMed

Lee, Jinho; Jung, Sung-Chul; Joo, Jaesoon; Choi, Yu-Ri; Moon, Hyo Won; Kwak, Geon; Yeo, Ha Kyung; Lee, Ji-Su; Ahn, Hye-Jee; Jung, Namhee; Hwang, Sunhee; Rheey, Jingeun; Woo, So-Youn; Kim, Ji Yon; Hong, Young Bin; Choi, Byung-Ok

2015-06-19

Mutations in heat shock 27 kDa protein 1 (HSP27 or HSPB1) cause distal hereditary motor neuropathy (dHMN) or Charcot-Marie-Tooth disease type 2 F (CMT2F) according to unknown factors. Mutant HSP27 proteins affect axonal transport by reducing acetylated tubulin. We generated a transgenic mouse model overexpressing HSP27-S135F mutant protein driven by Cytomegalovirus (CMV) immediate early promoter. The mouse phenotype was similar to dHMN patients in that they exhibit motor neuropathy. To determine the phenotypic aberration of transgenic mice, behavior test, magnetic resonance imaging (MRI), electrophysiological study, and pathology were performed. Rotarod test showed that founder mice exhibited lowered motor performance. MRI also revealed marked fatty infiltration in the anterior and posterior compartments at calf level. Electrophysiologically, compound muscle action potential (CMAP) but not motor nerve conduction velocity (MNCV) was reduced in the transgenic mice. Toluidine staining with semi-thin section of sciatic nerve showed the ratio of large myelinated axon fiber was reduced, which might cause reduced locomotion in the transgenic mice. Electron microscopy also revealed abundant aberrant myelination. Immunohistochemically, neuronal dysfunctions included elevated level of phosphorylated neurofilament and reduced level of acetylated tubulin in the sural nerve of transgenic mice. There was no additional phenotype besides motor neuronal defects. Overexpression of HSP27-S135F protein causes peripheral neuropathy. The mouse model can be applied to future development of therapeutic strategies for dHMN or CMT2F.

Distinct roles for motor neuron autophagy early and late in the SOD1G93A mouse model of ALS

PubMed Central

Rudnick, Noam D.; Griffey, Christopher J.; Guarnieri, Paolo; Gerbino, Valeria; Wang, Xueyong; Piersaint, Jason A.; Tapia, Juan Carlos; Rich, Mark M.; Maniatis, Tom

2017-01-01

Mutations in autophagy genes can cause familial and sporadic amyotrophic lateral sclerosis (ALS). However, the role of autophagy in ALS pathogenesis is poorly understood, in part due to the lack of cell type-specific manipulations of this pathway in animal models. Using a mouse model of ALS expressing mutant superoxide dismutase 1 (SOD1G93A), we show that motor neurons form large autophagosomes containing ubiquitinated aggregates early in disease progression. To investigate whether this response is protective or detrimental, we generated mice in which the critical autophagy gene Atg7 was specifically disrupted in motor neurons (Atg7 cKO). Atg7 cKO mice were viable but exhibited structural and functional defects at a subset of vulnerable neuromuscular junctions. By crossing Atg7 cKO mice to the SOD1G93A mouse model, we found that autophagy inhibition accelerated early neuromuscular denervation of the tibialis anterior muscle and the onset of hindlimb tremor. Surprisingly, however, lifespan was extended in Atg7 cKO; SOD1G93A double-mutant mice. Autophagy inhibition did not prevent motor neuron cell death, but it reduced glial inflammation and blocked activation of the stress-related transcription factor c-Jun in spinal interneurons. We conclude that motor neuron autophagy is required to maintain neuromuscular innervation early in disease but eventually acts in a non–cell-autonomous manner to promote disease progression. PMID:28904095

Preliminary crystallographic analysis of mouse Elf3 C-terminal DNA-binding domain in complex with type II TGF-[beta] receptor promoter DNA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agarkar, Vinod B.; Babayeva, Nigar D.; Rizzino, Angie

2010-10-08

Ets proteins are transcription factors that activate or repress the expression of genes that are involved in various biological processes, including cellular proliferation, differentiation, development, transformation and apoptosis. Like other Ets-family members, Elf3 functions as a sequence-specific DNA-binding transcriptional factor. A mouse Elf3 C-terminal fragment (amino-acid residues 269-371) containing the DNA-binding domain has been crystallized in complex with mouse type II TGF-{beta} receptor promoter (TR-II) DNA. The crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 42.66, b = 52, c = 99.78 {angstrom}, and diffracted to a resolution of 2.2 {angstrom}.

Facilitatory effects of piracetam on excitability of motor nerve terminals and neuromuscular transmission.

PubMed

Hall, E D; Von Voigtlander, P F

1987-11-01

The possible in vivo facilitatory effects of the pyrrolidine acetamide no-otropic agent piracetam on neuromuscular transmission, were studied based upon reports of enhancement of central cholinergic function. Piracetam was shown to antagonize the lethal effects of the neuromuscular blocking agent hemicholinium-3 (HC-3), in female CF-1 mice when administered in a dose of 100 mg/kg (i.p.) simultaneously with HC-3. A 30 mg/kg (i.p.) dose of piracetam was ineffective by itself, although it potentiated the protective effects of choline (25 mg/kg i.p.). The analogs of piracetam, aniracetam, oxiracetam, pramiracetam and dupracetam also significantly antagonized the lethality of HC-3 at doses over a 30-300 mg/kg range. The acute facilitatory properties of piracetam on neuromuscular transmission were examined in more detail in vivo in the soleus nerve muscle preparation of the cat. A 100 mg/kg (i.v.) dose of piracetam, while having no effect on its own, significantly enhanced the ability of a 200 micrograms/kg (i.v.) dose of edrophonium to produce a potentiation of muscle contraction dependent on repetitive discharges in the soleus motor nerve terminals. In preparations in which the motor nerve terminals of the soleus were in a partially degenerated state as a result of section of the motor axons 48 hr earlier, piracetam acted to restore their sensitivity to edrophonium. Furthermore, in both normal and partially degenerated preparations, piracetam significantly decreased the neuromuscular blocking effects of a 150 micrograms/kg (i.v.) dose of d-tubocurarine. The mechanism of the neuromuscular facilitatory effects of piracetam on neuromuscular transmission is discussed in terms of an enhanced excitability of motor nerve terminals together with an action to increase the synthesis and/or release of acetylcholine.

Central Projections of Antennal and Labial Palp Sensory Neurons in the Migratory Armyworm Mythimna separata

PubMed Central

Ma, Bai-Wei; Zhao, Xin-Cheng; Berg, Bente G.; Xie, Gui-Ying; Tang, Qing-Bo; Wang, Gui-Rong

2017-01-01

The oriental armyworm, Mythimna separata (Walker), is a polyphagous, migratory pest relying on olfactory cues to find mates, locate nectar, and guide long-distance flight behavior. In the present study, a combination of neuroanatomical techniques were utilized on this species, including backfills, confocal microscopy, and three-dimensional reconstructions, to trace the central projections of sensory neurons from the antenna and the labial pit organ, respectively. As previously shown, the axons of the labial sensory neurons project via the ipsilateral labial nerve and terminate in three main areas of the central nervous system: (1) the labial-palp pit organ glomerulus of each antennal lobe, (2) the gnathal ganglion, and (3) the prothoracic ganglion of the ventral nerve cord. Similarly, the antennal sensory axons project to multiple areas of the central nervous system. The ipsilateral antennal nerve targets mainly the antennal lobe, the antennal mechanosensory and motor center, and the prothoracic and mesothoracic ganglia. Specific staining experiments including dye application to each of the three antennal segments indicate that the antennal lobe receives input from flagellar olfactory neurons exclusively, while the antennal mechanosensory and motor center is innervated by mechanosensory neurons from the whole antenna, comprising the flagellum, pedicle, and scape. The terminals in the mechanosensory and motor center are organized in segregated zones relating to the origin of neurons. The flagellar mechanosensory axons target anterior zones, while the pedicular and scapal axons terminate in posterior zones. In the ventral nerve cord, the processes from the antennal sensory neurons terminate in the motor area of the thoracic ganglia, suggesting a close connection with motor neurons. Taken together, the numerous neuropils innervated by axons both from the antenna and labial palp indicate the multiple roles these sensory organs serve in insect behavior. PMID:29209176

Metabolic Reprogramming in Amyotrophic Lateral Sclerosis.

PubMed

Szelechowski, M; Amoedo, N; Obre, E; Léger, C; Allard, L; Bonneu, M; Claverol, S; Lacombe, D; Oliet, S; Chevallier, S; Le Masson, G; Rossignol, R

2018-03-02

Mitochondrial dysfunction in the spinal cord is a hallmark of amyotrophic lateral sclerosis (ALS), but the neurometabolic alterations during early stages of the disease remain unknown. Here, we investigated the bioenergetic and proteomic changes in ALS mouse motor neurons and patients' skin fibroblasts. We first observed that SODG93A mice presymptomatic motor neurons display alterations in the coupling efficiency of oxidative phosphorylation, along with fragmentation of the mitochondrial network. The proteome of presymptomatic ALS mice motor neurons also revealed a peculiar metabolic signature with upregulation of most energy-transducing enzymes, including the fatty acid oxidation (FAO) and the ketogenic components HADHA and ACAT2, respectively. Accordingly, FAO inhibition altered cell viability specifically in ALS mice motor neurons, while uncoupling protein 2 (UCP2) inhibition recovered cellular ATP levels and mitochondrial network morphology. These findings suggest a novel hypothesis of ALS bioenergetics linking FAO and UCP2. Lastly, we provide a unique set of data comparing the molecular alterations found in human ALS patients' skin fibroblasts and SODG93A mouse motor neurons, revealing conserved changes in protein translation, folding and assembly, tRNA aminoacylation and cell adhesion processes.

Comparison of the Effects of Low Volume Prilocaine and Alkalinized Prilocaine for the Regional Intravenous Anesthesia Technique in Hand and Wrist Surgery

PubMed Central

Kapusuz, Ozlem; Argun, Guldeniz; Arikan, Murat; Toğral, Guray; Basarir, Aysun; Kadiogullari, Nihal

2014-01-01

Aim. Comparing the effectivity of prilocaine and prilocaine alkalinized with 8.4% NaHCO3 in terms of sensory and motor block onset and termination durations in RIVA technique considering patients' satisfaction and tolerance with application of tourniquet undergoing hand-wrist surgery. Materials and Methods. 64 patients were randomised into two groups. First group (Group P) was administered prilocaine and second group (Group PN) was administered prilocaine + %8.4 NaHCO3. Sensory and motor block onset and termination times and onset of tourniquet pain were recorded. Results. No significant difference was found between the two groups in terms of onset and termination of sensory block and the onset of motor block. The duration of the motor block was longer in Group PN than in Group P (P < 0.05). Tourniquet pain was more intense in Group P (P = 0.036). In Group PN, the use of additional drugs was recorded at a lower rate and patients' satisfaction was higher than Group P. Conclusion. In the present study, it was established that alkalinization of prilocaine had no effect on the duration of sensory block and it prolonged the duration of motor block, increased patients' satisfaction, and decreased tourniquet pain. It is our suggestion that future studies should be carried out on the issue by using different volumes. PMID:25133177

Abnormal nuclear envelope in the cerebellar Purkinje cells and impaired motor learning in DYT11 myoclonus-dystonia mouse models.

PubMed

Yokoi, Fumiaki; Dang, Mai T; Yang, Guang; Li, Jindong; Doroodchi, Atbin; Zhou, Tong; Li, Yuqing

2012-02-01

Myoclonus-dystonia (M-D) is a movement disorder characterized by myoclonic jerks with dystonia. DYT11 M-D is caused by mutations in SGCE which codes for ɛ-sarcoglycan. SGCE is maternally imprinted and paternally expressed. Abnormal nuclear envelope has been reported in mouse models of DYT1 generalized torsion dystonia. However, it is not known whether similar alterations occur in DYT11 M-D. We developed a mouse model of DYT11 M-D using paternally inherited Sgce heterozygous knockout (Sgce KO) mice and reported that they had myoclonus and motor coordination and learning deficits in the beam-walking test. However, the specific brain regions that contribute to these phenotypes have not been identified. Since ɛ-sarcoglycan is highly expressed in the cerebellar Purkinje cells, here we examined the nuclear envelope in these cells using a transmission electron microscope and found that they are abnormal in Sgce KO mice. Our results put DYT11 M-D in a growing family of nuclear envelopathies. To analyze the effect of loss of ɛ-sarcoglycan function in the cerebellar Purkinje cells, we produced paternally inherited cerebellar Purkinje cell-specific Sgce conditional knockout (Sgce pKO) mice. Sgce pKO mice showed motor learning deficits, while they did not show abnormal nuclear envelope in the cerebellar Purkinje cells, robust motor deficits, or myoclonus. The results suggest that ɛ-sarcoglycan in the cerebellar Purkinje cells contributes to the motor learning, while loss of ɛ-sarcoglycan in other brain regions may contribute to nuclear envelope abnormality, myoclonus and motor coordination deficits. Copyright © 2011 Elsevier B.V. All rights reserved.

Brain BLAQ: Post-hoc thick-section histochemistry for localizing optogenetic constructs in neurons and their distal terminals

PubMed Central

Kupferschmidt, David A.; Cody, Patrick A.; Lovinger, David M.; Davis, Margaret I.

2015-01-01

Optogenetic constructs have revolutionized modern neuroscience, but the ability to accurately and efficiently assess their expression in the brain and associate it with prior functional measures remains a challenge. High-resolution imaging of thick, fixed brain sections would make such post-hoc assessment and association possible; however, thick sections often display autofluorescence that limits their compatibility with fluorescence microscopy. We describe and evaluate a method we call “Brain BLAQ” (Block Lipids and Aldehyde Quench) to rapidly reduce autofluorescence in thick brain sections, enabling efficient axon-level imaging of neurons and their processes in conventional tissue preparations using standard epifluorescence microscopy. Following viral-mediated transduction of optogenetic constructs and fluorescent proteins in mouse cortical pyramidal and dopaminergic neurons, we used BLAQ to assess innervation patterns in the striatum, a region in which autofluorescence often obscures the imaging of fine neural processes. After BLAQ treatment of 250–350 μm-thick brain sections, axons and puncta of labeled afferents were visible throughout the striatum using a standard epifluorescence stereomicroscope. BLAQ histochemistry confirmed that motor cortex (M1) projections preferentially innervated the matrix component of lateral striatum, whereas medial prefrontal cortex projections terminated largely in dorsal striosomes and distinct nucleus accumbens subregions. Ventral tegmental area dopaminergic projections terminated in a similarly heterogeneous pattern within nucleus accumbens and ventral striatum. Using a minimal number of easily manipulated and visualized sections, and microscopes available in most neuroscience laboratories, BLAQ enables simple, high-resolution assessment of virally transduced optogenetic construct expression, and post-hoc association of this expression with molecular markers, physiology and behavior. PMID:25698938

Generation of Combat Power by Insurgents: An Historical Analysis

DTIC Science & Technology

2013-06-13

the concept of operations. Transportation incorporates military, commercial, and multinational assets. Transportation includes motor , rail, air...and water modes. Transportation nodes include motor , rail, air, and water terminal operations. Transportation also includes movement control and

A G542X cystic fibrosis mouse model for examining nonsense mutation directed therapies.

PubMed

McHugh, Daniel R; Steele, Miarasa S; Valerio, Dana M; Miron, Alexander; Mann, Rachel J; LePage, David F; Conlon, Ronald A; Cotton, Calvin U; Drumm, Mitchell L; Hodges, Craig A

2018-01-01

Nonsense mutations are present in 10% of patients with CF, produce a premature termination codon in CFTR mRNA causing early termination of translation, and lead to lack of CFTR function. There are no currently available animal models which contain a nonsense mutation in the endogenous Cftr locus that can be utilized to test nonsense mutation therapies. In this study, we create a CF mouse model carrying the G542X nonsense mutation in Cftr using CRISPR/Cas9 gene editing. The G542X mouse model has reduced Cftr mRNA levels, demonstrates absence of CFTR function, and displays characteristic manifestations of CF mice such as reduced growth and intestinal obstruction. Importantly, CFTR restoration is observed in G542X intestinal organoids treated with G418, an aminoglycoside with translational readthrough capabilities. The G542X mouse model provides an invaluable resource for the identification of potential therapies of CF nonsense mutations as well as the assessment of in vivo effectiveness of these potential therapies targeting nonsense mutations.

The Effect of Self-Regulated and Experimenter-Imposed Practice Schedules on Motor Learning for Tasks of Varying Difficulty

ERIC Educational Resources Information Center

Keetch, Katherine M.; Lee, Timothy D.

2007-01-01

Research suggests that allowing individuals to control their own practice schedule has a positive effect on motor learning. In this experiment we examined the effect of task difficulty and self-regulated practice strategies on motor learning. The task was to move a mouse-operated cursor through pattern arrays that differed in two levels of…

4-aminopyridine reverses ataxia and cerebellar firing deficiency in a mouse model of spinocerebellar ataxia type 6

PubMed Central

Jayabal, Sriram; Chang, Hui Ho Vanessa; Cullen, Kathleen E.; Watt, Alanna J.

2016-01-01

Spinocerebellar ataxia type 6 (SCA6) is a devastating midlife-onset autosomal dominant motor control disease with no known treatment. Using a hyper-expanded polyglutamine (84Q) knock-in mouse, we found that cerebellar Purkinje cell firing precision was degraded in heterozygous (SCA684Q/+) mice at 19 months when motor deficits are observed. Similar alterations in firing precision and motor control were observed at disease onset at 7 months in homozygous (SCA684Q/84Q) mice, as well as a reduction in firing rate. We further found that chronic administration of the FDA-approved drug 4-aminopyridine (4-AP), which targets potassium channels, alleviated motor coordination deficits and restored cerebellar Purkinje cell firing precision to wildtype (WT) levels in SCA684Q/84Q mice both in acute slices and in vivo. These results provide a novel therapeutic approach for treating ataxic symptoms associated with SCA6. PMID:27381005

4-aminopyridine reverses ataxia and cerebellar firing deficiency in a mouse model of spinocerebellar ataxia type 6.

PubMed

Jayabal, Sriram; Chang, Hui Ho Vanessa; Cullen, Kathleen E; Watt, Alanna J

2016-07-06

Spinocerebellar ataxia type 6 (SCA6) is a devastating midlife-onset autosomal dominant motor control disease with no known treatment. Using a hyper-expanded polyglutamine (84Q) knock-in mouse, we found that cerebellar Purkinje cell firing precision was degraded in heterozygous (SCA6(84Q/+)) mice at 19 months when motor deficits are observed. Similar alterations in firing precision and motor control were observed at disease onset at 7 months in homozygous (SCA6(84Q/84Q)) mice, as well as a reduction in firing rate. We further found that chronic administration of the FDA-approved drug 4-aminopyridine (4-AP), which targets potassium channels, alleviated motor coordination deficits and restored cerebellar Purkinje cell firing precision to wildtype (WT) levels in SCA6(84Q/84Q) mice both in acute slices and in vivo. These results provide a novel therapeutic approach for treating ataxic symptoms associated with SCA6.

Closed-loop thrust and pressure profile throttling of a nitrous oxide/hydroxyl-terminated polybutadiene hybrid rocket motor

NASA Astrophysics Data System (ADS)

Peterson, Zachary W.

Hybrid motors that employ non-toxic, non-explosive components with a liquid oxidizer and a solid hydrocarbon fuel grain have inherently safe operating characteristics. The inherent safety of hybrid rocket motors offers the potential to greatly reduce overall operating costs. Another key advantage of hybrid rocket motors is the potential for in-flight shutdown, restart, and throttle by controlling the pressure drop between the oxidizer tank and the injector. This research designed, developed, and ground tested a closed-loop throttle controller for a hybrid rocket motor using nitrous oxide and hydroxyl-terminated polybutadiene as propellants. The research simultaneously developed closed-loop throttle algorithms and lab scale motor hardware to evaluate the fidelity of the throttle simulations and algorithms. Initial open-loop motor tests were performed to better classify system parameters and to validate motor performance values. Deep-throttle open-loop tests evaluated limits of stable thrust that can be achieved on the test hardware. Open-loop tests demonstrated the ability to throttle the motor to less than 10% of maximum thrust with little reduction in effective specific impulse and acoustical stability. Following the open-loop development, closed-loop, hardware-in-the-loop tests were performed. The closed-loop controller successfully tracked prescribed step and ramp command profiles with a high degree of fidelity. Steady-state accuracy was greatly improved over uncontrolled thrust.

Sumoylation of FOXP2 regulates motor function and vocal communication through Purkinje cell development

PubMed Central

Usui, Noriyoshi; Co, Marissa; Harper, Matthew; Rieger, Michael A.; Dougherty, Joseph D.; Konopka, Genevieve

2016-01-01

Background Mutations in the gene encoding the transcription factor forkhead box P2, FOXP2, result in brain developmental abnormalities including reduced gray matter in both human patients and rodent models, and speech and language deficits. However, neither the region-specific function of FOXP2 in the brain, in particular the cerebellum, nor the effects of any post-translational modifications of FOXP2 in the brain and disorders have been explored. Methods We characterized sumoylation of FOXP2 biochemically, and analyzed the region-specific function and sumoylation of FOXP2 in the developing mouse cerebellum. Using in utero electroporation to manipulate the sumoylation-state of Foxp2 as well as Foxp2 expression levels in Purkinje cells (PCs) of the cerebellum in vivo, we reduced Foxp2 expression approximately 40% in the mouse cerebellum. Such a reduction approximates the haploinsufficiency observed in human patients who demonstrate speech and language impairments. Results We identified sumoylation of FOXP2 at K674 (K673 in mouse) in the cerebellum of neonates. In vitro co-immunoprecipitation and in vivo colocalization experiments suggest that PIAS3 acts as the SUMO E3 ligase for FOXP2 sumoylation. This sumoylation modifies transcriptional regulation by FOXP2. We demonstrate that Foxp2 sumoylation is required for regulation of cerebellar motor function and vocal communication, likely through dendritic outgrowth and arborization of PCs in the mouse cerebellum. Conclusions Sumoylation of Foxp2 in neonatal mouse cerebellum regulates PC development as well as motor functions and vocal communication, demonstrating evidence for sumoylation in regulating mammalian behaviors. PMID:27009683

Early Detection of Motor Dysfunction in the SOD1G93A Mouse Model of Amyotrophic Lateral Sclerosis (ALS) Using Home Cage Running Wheels

PubMed Central

Bennett, Ellen J.; Mead, Richard J.; Azzouz, Mimoun; Shaw, Pamela J.; Grierson, Andrew J.

2014-01-01

The SOD1G93A mouse has been used since 1994 for preclinical testing in amyotrophic lateral sclerosis (ALS). Despite recent genetic advances in our understanding of ALS, transgenic mice expressing mutant SOD1 remain the best available, and most widely used, vertebrate model of the disease. We previously described an optimised and rapid approach for preclinical studies in the SOD1G93A mouse. Here we describe improvements to this approach using home cage running wheels to obtain daily measurements of motor function, with minimal intervention. We show that home cage running wheels detect reductions in motor function at a similar time to the rotarod test, and that the data obtained are less variable allowing the use of smaller groups of animals to obtain satisfactory results. This approach refines use of the SOD1G93A model, and reduces the number of animals undergoing procedures of substantial severity, two central principles of the 3Rs (replacement, reduction and refinement of animal use in research). The small group sizes and rapid timescales enable affordable large-scale therapeutic pre-screening in the SOD1G93A mouse, as well as rapid validation of published positive effects in a second laboratory, one of the major stumbling blocks in ALS preclinical therapy development. PMID:25268710

Generation and characterization of a human-mouse chimeric high-affinity antibody that detects the DYKDDDDK FLAG peptide.

PubMed

Ikeda, Koki; Koga, Tomoaki; Sasaki, Fumiyuki; Ueno, Ayumi; Saeki, Kazuko; Okuno, Toshiaki; Yokomizo, Takehiko

2017-05-13

DYKDDDDK peptide (FLAG) is a useful tool for investigating the function and localization of proteins whose antibodies (Abs) are not available. We recently established a high-affinity monoclonal antibody (mAb) for FLAG (clone 2H8). The 2H8 Ab is highly sensitive for detecting FLAG-tagged proteins by flowcytometry and immunoprecipitation, but it can yield nonspecific signals in immunohistochemistry of mouse tissues because it is of mouse origin. In this study, we reduced nonspecific signals by generating a chimeric 2H8 Ab with Fc fragments derived from human immunoglobulin. We fused a 5' terminal cDNA fragments for the Fab region of 2H8 mAb with 3' terminal cDNA fragments for Fc region of human IgG1. We transfected both chimeric plasmids and purified the resulting human-mouse chimeric 2H8. The chimeric 2H8 Ab successfully detected FLAG-tagged proteins in flowcytometry with anti-human IgG secondary Ab with comparable sensitivity to 2H8 mAb. Importantly, chimeric 2H8 detected specific FLAG peptide signals without nonspecific signals in immunohistochemical analysis with mouse tissues. This human-mouse chimeric high-affinity anti-FLAG Ab will prove useful for future immunohistochemical analysis of mouse tissues. Copyright © 2017 Elsevier Inc. All rights reserved.

Post-mortem immunodiagnosis of scrapie and bovine spongiform encephalopathy.

PubMed

Farquhar, C F; Somerville, R A; Ritchie, L A

1989-01-01

Two polyclonal antisera were raised in rabbits against the scrapie-associated fibril protein (PrP) prepared from sheep and mice which were terminally infected with experimental scrapie. The anti-mouse PrP serum identifies the proteins of scrapie-associated fibrils (SAF) from all the host species studied (mouse, hamster, sheep and goat) and bovine spongiform encephalopathy (BSE) fibrils from cow. The anti-sheep PrP serum displays species restricted immunoreactivity. While it identifies several PrP polypeptides from terminally affected sheep, goat and cow material, only the highest molecular weight band is recognised from hamster and there is no detection of mouse PrP. The use of these antisera in routine laboratory testing at post mortem provides a highly sensitive test for scrapie and BSE and may allow the identification of infected animals prior to the onset of clinical signs.

Co-induction of the heat shock response ameliorates disease progression in a mouse model of human spinal and bulbar muscular atrophy: implications for therapy

PubMed Central

Malik, Bilal; Nirmalananthan, Niranjanan; Gray, Anna L.; La Spada, Albert R.; Hanna, Michael G.

2013-01-01

Spinal and bulbar muscular atrophy, also known as Kennedy’s disease, is an adult-onset hereditary neurodegenerative disorder caused by an expansion of the polyglutamine repeat in the first exon in the androgen receptor gene. Pathologically, the disease is defined by selective loss of spinal and bulbar motor neurons causing bulbar, facial and limb weakness. Although the precise disease pathophysiology is largely unknown, it appears to be related to abnormal accumulation of the pathogenic androgen receptor protein within the nucleus, leading to disruption of cellular processes. Using a mouse model of spinal and bulbar muscular atrophy that exhibits many of the characteristic features of the human disease, in vivo physiological assessment of muscle function revealed that mice with the pathogenic expansion of the androgen receptor develop a motor deficit characterized by a reduction in muscle force, abnormal muscle contractile characteristics, loss of functional motor units and motor neuron degeneration. We have previously shown that treatment with arimoclomol, a co-inducer of the heat shock stress response, delays disease progression in the mutant superoxide dismutase 1 mouse model of amyotrophic lateral sclerosis, a fatal motor neuron disease. We therefore evaluated the therapeutic potential of arimoclomol in mice with spinal and bulbar muscular atrophy. Arimoclomol was administered orally, in drinking water, from symptom onset and the effects established at 18 months of age, a late stage of disease. Arimoclomol significantly improved hindlimb muscle force and contractile characteristics, rescued motor units and, importantly, improved motor neuron survival and upregulated the expression of the vascular endothelial growth factor which possess neurotrophic activity. These results provide evidence that upregulation of the heat shock response by treatment with arimoclomol may have therapeutic potential in the treatment of spinal and bulbar muscular atrophy and may also be a possible approach for the treatment of other neurodegenerative diseases. PMID:23393146

Treadmill exercise delays the onset of non-motor behaviors and striatal pathology in the CAG140 knock-in mouse model of Huntington's disease.

PubMed

Stefanko, D P; Shah, V D; Yamasaki, W K; Petzinger, G M; Jakowec, M W

2017-09-01

Depression, cognitive impairments, and other neuropsychiatric disturbances are common during the prodromal phase of Huntington's disease (HD) well before the onset of classical motor symptoms of this degenerative disorder. The purpose of this study was to examine the potential impact of physical activity in the form of exercise on a motorized treadmill on non-motor behavioral features including depression-like behavior and cognition in the CAG 140 knock-in (KI) mouse model of HD. The CAG 140 KI mouse model has a long lifespan compared to other HD rodent models with HD motor deficits emerging after 12months of age and thus provides the opportunity to investigate early life interventions such as exercise on disease progression. Motorized treadmill running was initiated at 4weeks of age (1h per session, 3 times per week) and continued for 6months. Non-motor behaviors were assessed up to 6months of age and included analysis of depression-like behavior (using the tail-suspension and forced-swim tests) and cognition (using the T-maze and object recognition tests). At both 4 and 6months of age, CAG 140 KI mice displayed significant depression-like behavior in the forced swim and tail suspension tests and cognitive impairment by deficits in reversal relearning in the T-maze test. These deficits were not evident in mice engaged in treadmill running. In addition, exercise restored striatal dopamine D2 receptor expression and dopamine neurotransmitter levels both reduced in sedentary HD mice. Finally, we examined the pattern of striatal expression of mutant huntingtin (mHTT) protein and showed that the number and intensity of immunohistochemical staining patterns of intranuclear aggregates were significantly reduced with exercise. Altogether these findings begin to address the potential impact of lifestyle and early intervention such as exercise on modifying HD progression. Copyright © 2017 Elsevier Inc. All rights reserved.

A new mouse model of ARX dup24 recapitulates the patients' behavioral and fine motor alterations.

PubMed

Dubos, Aline; Meziane, Hamid; Iacono, Giovanni; Curie, Aurore; Riet, Fabrice; Martin, Christelle; Loaëc, Nadège; Birling, Marie-Christine; Selloum, Mohammed; Normand, Elisabeth; Pavlovic, Guillaume; Sorg, Tania; Stunnenberg, Henk G; Chelly, Jamel; Humeau, Yann; Friocourt, Gaëlle; Hérault, Yann

2018-06-15

The aristaless-related homeobox (ARX) transcription factor is involved in the development of GABAergic and cholinergic neurons in the forebrain. ARX mutations have been associated with a wide spectrum of neurodevelopmental disorders in humans, among which the most frequent, a 24 bp duplication in the polyalanine tract 2 (c.428_451dup24), gives rise to intellectual disability, fine motor defects with or without epilepsy. To understand the functional consequences of this mutation, we generated a partially humanized mouse model carrying the c.428_451dup24 duplication (Arxdup24/0) that we characterized at the behavior, neurological and molecular level. Arxdup24/0 males presented with hyperactivity, enhanced stereotypies and altered contextual fear memory. In addition, Arxdup24/0 males had fine motor defects with alteration of reaching and grasping abilities. Transcriptome analysis of Arxdup24/0 forebrains at E15.5 showed a down-regulation of genes specific to interneurons and an up-regulation of genes normally not expressed in this cell type, suggesting abnormal interneuron development. Accordingly, interneuron migration was altered in the cortex and striatum between E15.5 and P0 with consequences in adults, illustrated by the defect in the inhibitory/excitatory balance in Arxdup24/0 basolateral amygdala. Altogether, we showed that the c.428_451dup24 mutation disrupts Arx function with a direct consequence on interneuron development, leading to hyperactivity and defects in precise motor movement control and associative memory. Interestingly, we highlighted striking similarities between the mouse phenotype and a cohort of 33 male patients with ARX c.428_451dup24, suggesting that this new mutant mouse line is a good model for understanding the pathophysiology and evaluation of treatment.

A new mouse model of ARX dup24 recapitulates the patients’ behavioral and fine motor alterations

PubMed Central

Dubos, Aline; Meziane, Hamid; Iacono, Giovanni; Curie, Aurore; Riet, Fabrice; Martin, Christelle; Loaëc, Nadège; Birling, Marie-Christine; Selloum, Mohammed; Normand, Elisabeth; Pavlovic, Guillaume; Sorg, Tania; Stunnenberg, Henk G; Chelly, Jamel; Humeau, Yann; Friocourt, Gaëlle; Hérault, Yann

2018-01-01

Abstract The aristaless-related homeobox (ARX) transcription factor is involved in the development of GABAergic and cholinergic neurons in the forebrain. ARX mutations have been associated with a wide spectrum of neurodevelopmental disorders in humans, among which the most frequent, a 24 bp duplication in the polyalanine tract 2 (c.428_451dup24), gives rise to intellectual disability, fine motor defects with or without epilepsy. To understand the functional consequences of this mutation, we generated a partially humanized mouse model carrying the c.428_451dup24 duplication (Arxdup24/0) that we characterized at the behavior, neurological and molecular level. Arxdup24/0 males presented with hyperactivity, enhanced stereotypies and altered contextual fear memory. In addition, Arxdup24/0 males had fine motor defects with alteration of reaching and grasping abilities. Transcriptome analysis of Arxdup24/0 forebrains at E15.5 showed a down-regulation of genes specific to interneurons and an up-regulation of genes normally not expressed in this cell type, suggesting abnormal interneuron development. Accordingly, interneuron migration was altered in the cortex and striatum between E15.5 and P0 with consequences in adults, illustrated by the defect in the inhibitory/excitatory balance in Arxdup24/0 basolateral amygdala. Altogether, we showed that the c.428_451dup24 mutation disrupts Arx function with a direct consequence on interneuron development, leading to hyperactivity and defects in precise motor movement control and associative memory. Interestingly, we highlighted striking similarities between the mouse phenotype and a cohort of 33 male patients with ARX c.428_451dup24, suggesting that this new mutant mouse line is a good model for understanding the pathophysiology and evaluation of treatment. PMID:29659809

Time-Restricted Feeding Improves Circadian Dysfunction as well as Motor Symptoms in the Q175 Mouse Model of Huntington's Disease.

PubMed

Wang, Huei-Bin; Loh, Dawn H; Whittaker, Daniel S; Cutler, Tamara; Howland, David; Colwell, Christopher S

2018-01-01

Huntington's disease (HD) patients suffer from a progressive neurodegeneration that results in cognitive, psychiatric, cardiovascular, and motor dysfunction. Disturbances in sleep/wake cycles are common among HD patients with reports of delayed sleep onset, frequent bedtime awakenings, and fatigue during the day. The heterozygous Q175 mouse model of HD has been shown to phenocopy many HD core symptoms including circadian dysfunctions. Because circadian dysfunction manifests early in the disease in both patients and mouse models, we sought to determine if early intervention that improve circadian rhythmicity can benefit HD and delay disease progression. We determined the effects of time-restricted feeding (TRF) on the Q175 mouse model. At six months of age, the animals were divided into two groups: ad libitum (ad lib) and TRF. The TRF-treated Q175 mice were exposed to a 6-h feeding/18-h fasting regimen that was designed to be aligned with the middle of the time when mice are normally active. After three months of treatment (when mice reached the early disease stage), the TRF-treated Q175 mice showed improvements in their locomotor activity rhythm and sleep awakening time. Furthermore, we found improved heart rate variability (HRV), suggesting that their autonomic nervous system dysfunction was improved. Importantly, treated Q175 mice exhibited improved motor performance compared to untreated Q175 controls, and the motor improvements were correlated with improved circadian output. Finally, we found that the expression of several HD-relevant markers was restored to WT levels in the striatum of the treated mice using NanoString gene expression assays.

Motor Deficits and Decreased Striatal Dopamine Receptor 2 Binding Activity in the Striatum-Specific Dyt1 Conditional Knockout Mice

PubMed Central

Yokoi, Fumiaki; Dang, Mai Tu; Li, Jianyong; Standaert, David G.; Li, Yuqing

2011-01-01

DYT1 early-onset generalized dystonia is a hyperkinetic movement disorder caused by mutations in DYT1 (TOR1A), which codes for torsinA. Recently, significant progress has been made in studying pathophysiology of DYT1 dystonia using targeted mouse models. Dyt1 ΔGAG heterozygous knock-in (KI) and Dyt1 knock-down (KD) mice exhibit motor deficits and alterations of striatal dopamine metabolisms, while Dyt1 knockout (KO) and Dyt1 ΔGAG homozygous KI mice show abnormal nuclear envelopes and neonatal lethality. However, it has not been clear whether motor deficits and striatal abnormality are caused by Dyt1 mutation in the striatum itself or the end results of abnormal signals from other brain regions. To identify the brain region that contributes to these phenotypes, we made a striatum-specific Dyt1 conditional knockout (Dyt1 sKO) mouse. Dyt1 sKO mice exhibited motor deficits and reduced striatal dopamine receptor 2 (D2R) binding activity, whereas they did not exhibit significant alteration of striatal monoamine contents. Furthermore, we also found normal nuclear envelope structure in striatal medium spiny neurons (MSNs) of an adult Dyt1 sKO mouse and cerebral cortical neurons in cerebral cortex-specific Dyt1 conditional knockout (Dyt1 cKO) mice. The results suggest that the loss of striatal torsinA alone is sufficient to produce motor deficits, and that this effect may be mediated, at least in part, through changes in D2R function in the basal ganglia circuit. PMID:21931745

Electroacupuncture remediates glial dysfunction and ameliorates neurodegeneration in the astrocytic α-synuclein mutant mouse model.

PubMed

Deng, Jiahui; Lv, E; Yang, Jian; Gong, Xiaoli; Zhang, Wenzhong; Liang, Xibin; Wang, Jiazeng; Jia, Jun; Wang, Xiaomin

2015-05-28

The acupuncture or electroacupuncture (EA) shows the therapeutic effect on various neurodegenerative diseases. This effect was thought to be partially achieved by its ability to alleviate existing neuroinflammation and glial dysfunction. In this study, we systematically investigated the effect of EA on abnormal neurochemical changes and motor symptoms in a mouse neurodegenerative disease model. The transgenic mouse which expresses a mutant α-synuclein (α-syn) protein, A53T α-syn, in brain astrocytic cells was used. These mice exhibit extensive neuroinflammatory and motor phenotypes of neurodegenerative disorders. In this study, the effects of EA on these phenotypic changes were examined in these mice. EA improved the movement detected in multiple motor tests in A53T mutant mice. At the cellular level, EA significantly reduced the activation of microglia and prevented the loss of dopaminergic neurons in the midbrain and motor neurons in the spinal cord. At the molecular level, EA suppressed the abnormal elevation of proinflammatory factors (tumor necrosis factor-α and interleukin-1β) in the striatum and midbrain of A53T mice. In contrast, EA increased striatal and midbrain expression of a transcription factor, nuclear factor E2-related factor 2, and its downstream antioxidants (heme oxygenase-1 and glutamate-cysteine ligase modifier subunits). These results suggest that EA possesses the ability to ameliorate mutant α-syn-induced motor abnormalities. This ability may be due to that EA enhances both anti-inflammatory and antioxidant activities and suppresses aberrant glial activation in the diseased sites of brains.

Promoter-proximal rDNA terminator augments initiation by preventing disruption of the stable transcription complex caused by polymerase read-in

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henderson, S.L.; Ryan, K.; Sollner-Webb, B.

1989-02-01

We have examined the mechanism by which transcriptional initiation at the mouse rDNA promoter is augmented by the RNA polymerase I terminator element that resides just upstream of it. Using templates in which terminator elements are instead positioned at the opposite side of the plasmid rather than proximal to the promoter, or conditions where transcription is terminated elsewhere in the plasmid by UV-induced lesions, we show that the terminator's stimulatory effect is not position dependent. Mouse terminator elements therefore do not stimulate via the previously postulated 'read-through enhancement' model in which terminated polymerases are handed off to an adjacent promotermore » in a concerted reaction. The position independence and orientation dependence of the terminator also makes it unlikely that the terminator functions as a promoter element or as an enhancer. Instead, terminators serve to augment initiation by preventing polymerases from reading completely around the plasmid and through the promoter from upstream, an event which we show interferes with subsequent rounds of initiation. Notably, this transcriptional interference arises because polymerase passage across a promoter disrupts the otherwise stable transcription complex, specifically releasing the bound transcription factor D. These liberated D molecules can then bind to other templates and activate their expression. The rDNA transcriptional interference is not due to a steric impediment to the binding of new polymerase molecules, and it does not similarly liberate the initiation-competent polymerase (factor C). These studies have also convincingly demonstrated that multiple rounds of transcription are obtained from rDNA template molecules in vitro.« less

(14)C METHANOL INCORPORATION INTO DNA AND SPECIFIC PROTEINS OF ORGANOGENESIS STAGE MOUSE EMBRYOS IN VITRO

EPA Science Inventory

Methanol (MeOH), a widely used industrial solvent and alternative motor fuel, has been shown to be mutagenic and teratogenic. We have demonstrated that methanol is teratogenic in mice in vivo and causes dysmorphogenesis in cultured organogenesis stage mouse embryos. Methanol is ...

Contribution of trimeric autotransporter C-terminal domains of oligomeric coiled-coil adhesin (Oca) family members YadA, UspA1, EibA, and Hia to translocation of the YadA passenger domain and virulence of Yersinia enterocolitica.

PubMed

Ackermann, Nikolaus; Tiller, Maximilian; Anding, Gisela; Roggenkamp, Andreas; Heesemann, Jürgen

2008-07-01

The Oca family is a novel class of autotransporter-adhesins with highest structural similarity in their C-terminal transmembrane region, which supposedly builds a beta-barrel pore in the outer membrane (OM). The prototype of the Oca family is YadA, an adhesin of Yersinia enterocolitica and Yersinia pseudotuberculosis. YadA forms a homotrimeric lollipop-like structure on the bacterial surface. The C-terminal regions of three YadA monomers form a barrel in the OM and translocate the trimeric N-terminal passenger domain, consisting of stalk, neck, and head region to the exterior. To elucidate the structural and functional role of the C-terminal translocator domain (TLD) and to assess its promiscuous capability with respect to transport of related passenger domains, we constructed chimeric YadA proteins, which consist of the N-terminal YadA passenger domain and C-terminal TLDs of Oca family members UspA1 (Moraxella catarrhalis), EibA (Escherichia coli), and Hia (Haemophilus influenzae). These constructs were expressed in Y. enterocolitica and compared for OM localization, surface exposure, oligomerization, adhesion properties, serum resistance, and mouse virulence. We demonstrate that all chimeric YadA proteins translocated the YadA passenger domain across the OM. Y. enterocolitica strains producing YadA chimeras or wild-type YadA showed comparable binding to collagen and epithelial cells. However, strains producing YadA chimeras were attenuated in serum resistance and mouse virulence. These results demonstrate for the first time that TLDs of Oca proteins of different origin are efficient translocators of the YadA passenger domain and that the cognate TLD of YadA is essential for bacterial survival in human serum and mouse virulence.

Isl1 Is required for multiple aspects of motor neuron development

PubMed Central

Liang, Xingqun; Song, Mi-Ryoung; Xu, ZengGuang; Lanuza, Guillermo M.; Liu, Yali; Zhuang, Tao; Chen, Yihan; Pfaff, Samuel L.; Evans, Sylvia M.; Sun, Yunfu

2011-01-01

The LIM homeodomain transcription factor Islet1 (Isl1) is expressed in multiple organs and plays essential roles during embryogenesis. Isl1 is required for the survival and specification of spinal cord motor neurons. Due to early embryonic lethality and loss of motor neurons, the role of Isl1 in other aspects of motor neuron development remains unclear. In this study, we generated Isl1 mutant mouse lines expressing graded doses of Isl1. Our study has revealed essential roles of Isl1 in multiple aspects of motor neuron development, including motor neuron cell body localization, motor column formation and axon growth. In addition, Isl1 is required for survival of cranial ganglia neurons. PMID:21569850

Abnormal nuclear envelopes in the striatum and motor deficits in DYT11 myoclonus-dystonia mouse models.

PubMed

Yokoi, Fumiaki; Dang, Mai T; Zhou, Tong; Li, Yuqing

2012-02-15

DYT11 myoclonus-dystonia (M-D) is a movement disorder characterized by myoclonic jerks with dystonic symptoms and caused by mutations in paternally expressed SGCE, which codes for ε-sarcoglycan. Paternally inherited Sgce heterozygous knock-out (KO) mice exhibit motor deficits and spontaneous myoclonus. Abnormal nuclear envelopes have been reported in cellular and mouse models of early-onset DYT1 generalized torsion dystonia; however, the relationship between the abnormal nuclear envelopes and motor symptoms are not clear. Furthermore, it is not known whether abnormal nuclear envelope exists in non-DYT1 dystonia. In the present study, abnormal nuclear envelopes in the striatal medium spiny neurons (MSNs) were found in Sgce KO mice. To analyze whether the loss of ε-sarcoglycan in the striatum alone causes abnormal nuclear envelopes, motor deficits or myoclonus, we produced paternally inherited striatum-specific Sgce conditional KO (Sgce sKO) mice and analyzed their phenotypes. Sgce sKO mice exhibited motor deficits in both beam-walking and accelerated rotarod tests, while they did not exhibit abnormal nuclear envelopes, alteration in locomotion, or myoclonus. The results suggest that the loss of ε-sarcoglycan in the striatum contributes to motor deficits, while it alone does not produce abnormal nuclear envelopes or myoclonus. Development of therapies targeting the striatum to compensate for the loss of ε-sarcoglycan function may rescue the motor deficits in DYT11 M-D patients.

Dysfunction in endoplasmic reticulum-mitochondria crosstalk underlies SIGMAR1 loss of function mediated motor neuron degeneration.

PubMed

Bernard-Marissal, Nathalie; Médard, Jean-Jacques; Azzedine, Hamid; Chrast, Roman

2015-04-01

Mutations in Sigma 1 receptor (SIGMAR1) have been previously identified in patients with amyotrophic lateral sclerosis and disruption of Sigmar1 in mouse leads to locomotor deficits. However, cellular mechanisms underlying motor phenotypes in human and mouse with disturbed SIGMAR1 function have not been described so far. Here we used a combination of in vivo and in vitro approaches to investigate the role of SIGMAR1 in motor neuron biology. Characterization of Sigmar1(-/-) mice revealed that affected animals display locomotor deficits associated with muscle weakness, axonal degeneration and motor neuron loss. Using primary motor neuron cultures, we observed that pharmacological or genetic inactivation of SIGMAR1 led to motor neuron axonal degeneration followed by cell death. Disruption of SIGMAR1 function in motor neurons disturbed endoplasmic reticulum-mitochondria contacts, affected intracellular calcium signalling and was accompanied by activation of endoplasmic reticulum stress and defects in mitochondrial dynamics and transport. These defects were not observed in cultured sensory neurons, highlighting the exacerbated sensitivity of motor neurons to SIGMAR1 function. Interestingly, the inhibition of mitochondrial fission was sufficient to induce mitochondria axonal transport defects as well as axonal degeneration similar to the changes observed after SIGMAR1 inactivation or loss. Intracellular calcium scavenging and endoplasmic reticulum stress inhibition were able to restore mitochondrial function and consequently prevent motor neuron degeneration. These results uncover the cellular mechanisms underlying motor neuron degeneration mediated by loss of SIGMAR1 function and provide therapeutically relevant insight into motor neuronal diseases. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

78 FR 14963 - Foreign-Trade Subzone 38A; Termination of Review of Application for Expansion; BMW Manufacturing...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-08

... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Docket 43-2011] Foreign-Trade Subzone 38A; Termination of Review of Application for Expansion; BMW Manufacturing Co., LLC (Motor Vehicles); Greer, South Carolina Notice is hereby given of termination of review of an application submitted by the South Carolina State Ports Authority, grantee of FTZ...

Novel test of motor and other dysfunctions in mouse neurological disease models.

PubMed

Barth, Albert M I; Mody, Istvan

2014-01-15

Just like human neurological disorders, corresponding mouse models present multiple deficiencies. Estimating disease progression or potential treatment effectiveness in such models necessitates the use of time consuming and multiple tests usually requiring a large number of scarcely available genetically modified animals. Here we present a novel and simple single camera arrangement and analysis software for detailed motor function evaluation in mice walking on a wire mesh that provides complex 3D information (instantaneous position, speed, distance traveled, foot fault depth, duration, location, relationship to speed of movement, etc.). We investigated 3 groups of mice with various neurological deficits: (1) unilateral motor cortical stroke; (2) effects of moderate ethanol doses; and (3) aging (96-99 weeks old). We show that post stroke recovery can be divided into separate stages based on strikingly different characteristics of motor function deficits, some resembling the human motor neglect syndrome. Mice treated with moderate dose of alcohol and aged mice showed specific motor and exploratory deficits. Other tests rely either partially or entirely on manual video analysis introducing a significant subjective component into the analysis, and analyze a single aspect of motor function. Our novel experimental approach provides qualitatively new, complex information about motor impairments and locomotor/exploratory activity. It should be useful for the detailed characterization of a broad range of human neurological disease models in mice, and for the more accurate assessment of disease progression or treatment effectiveness. Copyright © 2013 Elsevier B.V. All rights reserved.

Effects of Antiepileptic Drugs on Spontaneous Recurrent Seizures in a Novel Model of Extended Hippocampal Kindling in Mice.

PubMed

Song, Hongmei; Tufa, Uilki; Chow, Jonathan; Sivanenthiran, Nila; Cheng, Chloe; Lim, Stellar; Wu, Chiping; Feng, Jiachun; Eubanks, James H; Zhang, Liang

2018-01-01

Epilepsy is a common neurological disorder characterized by naturally-occurring spontaneous recurrent seizures and comorbidities. Kindling has long been used to model epileptogenic mechanisms and to assess antiepileptic drugs. In particular, extended kindling can induce spontaneous recurrent seizures without gross brain lesions, as seen clinically. To date, the development of spontaneous recurrent seizures following extended kindling, and the effect of the antiepileptic drugs on these seizures are not well understood. In the present study we aim to develop a mouse model of extended hippocampal kindling for the first time. Once established, we plan to evaluate the effect of three different antiepileptic drugs on the development of the extended-hippocampal-kindled-induced spontaneous recurrent seizures. Male C57 black mice were used for chronic hippocampal stimulations or handling manipulations (twice daily for up to 70 days). Subsequently, animals underwent continuous video/EEG monitoring for seizure detection. Spontaneous recurrent seizures were consistently observed in extended kindled mice but no seizures were detected in the control animals. The aforementioned seizures were generalized events characterized by hippocampal ictal discharges and concurrent motor seizures. Incidence and severity of the seizures was relatively stable while monitored over a few months after termination of the hippocampal stimulation. Three antiepileptic drugs with distinct action mechanisms were tested: phenytoin, lorazepam and levetiracetam. They were applied via intra-peritoneal injections at anticonvulsive doses and their effects on the spontaneous recurrent seizures were analyzed 10-12 h post-injection. Phenytoin (25 mg/kg) and levetiracetam (400 mg/kg) abolished the spontaneous recurrent seizures. Lorazepam (1.5 mg/kg) decreased motor seizure severity but did not reduce the incidence and duration of corresponding hippocampal discharges, implicating its inhibitory effects on seizure spread. No gross brain lesions were observed in a set of extended hippocampal kindled mice submitted to histological evaluation. All these data suggests that our model could be considered as a novel mouse model of extended hippocampal kindling. Some limitations remain to be considered.

Expression of Terminal Effector Genes in Mammalian Neurons Is Maintained by a Dynamic Relay of Transient Enhancers.

PubMed

Rhee, Ho Sung; Closser, Michael; Guo, Yuchun; Bashkirova, Elizaveta V; Tan, G Christopher; Gifford, David K; Wichterle, Hynek

2016-12-21

Generic spinal motor neuron identity is established by cooperative binding of programming transcription factors (TFs), Isl1 and Lhx3, to motor-neuron-specific enhancers. How expression of effector genes is maintained following downregulation of programming TFs in maturing neurons remains unknown. High-resolution exonuclease (ChIP-exo) mapping revealed that the majority of enhancers established by programming TFs are rapidly deactivated following Lhx3 downregulation in stem-cell-derived hypaxial motor neurons. Isl1 is released from nascent motor neuron enhancers and recruited to new enhancers bound by clusters of Onecut1 in maturing neurons. Synthetic enhancer reporter assays revealed that Isl1 operates as an integrator factor, translating the density of Lhx3 or Onecut1 binding sites into transient enhancer activity. Importantly, independent Isl1/Lhx3- and Isl1/Onecut1-bound enhancers contribute to sustained expression of motor neuron effector genes, demonstrating that outwardly stable expression of terminal effector genes in postmitotic neurons is controlled by a dynamic relay of stage-specific enhancers. Copyright © 2016 Elsevier Inc. All rights reserved.

Specific induction of Akt3 in spinal cord motor neurons is neuroprotective in a mouse model of familial amyotrophic lateral sclerosis.

PubMed

Peviani, Marco; Tortarolo, Massimo; Battaglia, Elisa; Piva, Roberto; Bendotti, Caterina

2014-02-01

Evidence is accumulating that an imbalance between pathways for degeneration or survival in motor neurons may play a central role in mechanisms that lead to neurodegeneration in amyotrophic lateral sclerosis (ALS). We and other groups have observed that downregulation, or lack of induction, of the PI3K/Akt prosurvival pathway may be responsible for defective response of motor neurons to injury and their consequent cellular demise. Some of the neuroprotective effects mediated by growth factors may involve activation of Akt, but a proof of concept of Akt as a target for therapy is lacking. We demonstrate that specific expression of constitutively activated Akt3 in motor neurons through the use of the promoter of homeobox gene Hb9 prevents neuronal loss induced by SOD1.G93A both in vitro (in mixed neuron/astrocyte cocultures) and in vivo (in a mouse model of ALS). Inhibition of ASK1 and GSK3beta was involved in the neuroprotective effects of activated Akt3, further supporting the hypothesis that induction of Akt3 may be a key step in activation of pathways for survival in the attempt to counteract motor neuronal degeneration in ALS.

Rapid Onset of Motor Deficits in a Mouse Model of Spinocerebellar Ataxia Type 6 Precedes Late Cerebellar Degeneration1,2,3

PubMed Central

Ljungberg, Lovisa; Cormier, Alexander; Quilez, Sabrina

2015-01-01

Abstract Spinocerebellar ataxia type 6 (SCA6) is an autosomal-dominant cerebellar ataxia that has been associated with loss of cerebellar Purkinje cells. Disease onset is typically at midlife, although it can vary widely from late teens to old age in SCA6 patients. Our study focused on an SCA6 knock-in mouse model with a hyper-expanded (84X) CAG repeat expansion that displays midlife-onset motor deficits at ∼7 months old, reminiscent of midlife-onset symptoms in SCA6 patients, although a detailed phenotypic analysis of these mice has not yet been reported. Here, we characterize the onset of motor deficits in SCA684Q mice using a battery of behavioral assays to test for impairments in motor coordination, balance, and gait. We found that these mice performed normally on these assays up to and including at 6 months, but motor impairment was detected at 7 months with all motor coordination assays used, suggesting that motor deficits emerge rapidly during a narrow age window in SCA684Q mice. In contrast to what is seen in SCA6 patients, the decrease in motor coordination was observed without alterations in gait. No loss of cerebellar Purkinje cells or striatal neurons were observed at 7 months, the age at which motor deficits were first detected, but significant Purkinje cell loss was observed in 2-year-old SCA684Q mice, arguing that Purkinje cell death does not significantly contribute to the early stages of SCA6. PMID:26730403

Striatal Synaptic Dysfunction and Hippocampal Plasticity Deficits in the Hu97/18 Mouse Model of Huntington Disease

PubMed Central

Kolodziejczyk, Karolina; Parsons, Matthew P.; Southwell, Amber L.; Hayden, Michael R.; Raymond, Lynn A.

2014-01-01

Huntington disease (HD) is a fatal neurodegenerative disorder caused by a CAG repeat expansion in the gene (HTT) encoding the huntingtin protein (HTT). This mutation leads to multiple cellular and synaptic alterations that are mimicked in many current HD animal models. However, the most commonly used, well-characterized HD models do not accurately reproduce the genetics of human disease. Recently, a new ‘humanized’ mouse model, termed Hu97/18, has been developed that genetically recapitulates human HD, including two human HTT alleles, no mouse Hdh alleles and heterozygosity of the HD mutation. Previously, behavioral and neuropathological testing in Hu97/18 mice revealed many features of HD, yet no electrophysiological measures were employed to investigate possible synaptic alterations. Here, we describe electrophysiological changes in the striatum and hippocampus of the Hu97/18 mice. At 9 months of age, a stage when cognitive deficits are fully developed and motor dysfunction is also evident, Hu97/18 striatal spiny projection neurons (SPNs) exhibited small changes in membrane properties and lower amplitude and frequency of spontaneous excitatory postsynaptic currents (sEPSCs); however, release probability from presynaptic terminals was unaltered. Strikingly, these mice also exhibited a profound deficiency in long-term potentiation (LTP) at CA3-to-CA1 synapses. In contrast, at 6 months of age we found only subtle alterations in SPN synaptic transmission, while 3-month old animals did not display any electrophysiologically detectable changes in the striatum and CA1 LTP was intact. Together, these data reveal robust, progressive deficits in synaptic function and plasticity in Hu97/18 mice, consistent with previously reported behavioral abnormalities, and suggest an optimal age (9 months) for future electrophysiological assessment in preclinical studies of HD. PMID:24728353

Terminal Distribution of the Corticospinal Projection from the Hand/Arm Region of the Primary Motor Cortex to the Cervical Enlargement in Rhesus Monkey

PubMed Central

Morecraft, Robert J.; Ge, Jizhi; Stilwell-Morecraft, Kimberly S.; McNeal, David W.; Pizzimenti, Marc A.; Darling, Warren G.

2013-01-01

To further our understanding of the corticospinal projection (CSP) from the hand/arm representation of the primary motor cortex (M1), high-resolution anterograde tracing methodology and stereology were used to investigate the terminal distribution of this connection at spinal levels C5 to T1. The highest number of labeled terminal boutons occurred contralaterally (98%) with few ipsilaterally (2%). Contralaterally, labeled boutons were located within laminae I – X, with the densest distribution found in lamina VII and, to a lesser extent, laminae IX and VI. Fewer terminals were found in other contralateral laminae. Within lamina VII, terminal boutons were most prominent in the dorsomedial, dorsolateral and ventrolateral subsectors. Within lamina IX, the heaviest terminal labeling was distributed dorsally. Ipsilaterally, boutons were found in laminae V – X. The most pronounced distribution occurred in the dorsomedial and ventromedial sectors of lamina VII and fewer labeled boutons were located in other ipsilateral laminae. Segmentally, contralateral lamina VII labeling was highest at levels C5-C7. In contrast, lamina IX labeling was highest at C7-T1 and more widely dispersed amongst the quadrants at C8-T1. Our findings suggest dominant contralateral influence of the M1 hand/arm CSP, a contralateral innervation pattern in lamina VII supporting Kuypers (1982) conceptual framework of a “lateral motor system”, and a projection to lamina IX indicating significant influence on motoneurons innervating flexors acting on the shoulder and elbow rostrally (C5-C7), along with flexors, extensors, abductors and adductors acting on the digits, hand and wrist caudally (C8-T1). PMID:23840034

Structure and inhibition analysis of the mouse SAD-B C-terminal fragment.

PubMed

Ma, Hui; Wu, Jing-Xiang; Wang, Jue; Wang, Zhi-Xin; Wu, Jia-Wei

2016-10-01

The SAD (synapses of amphids defective) kinases, including SAD-A and SAD-B, play important roles in the regulation of neuronal development, cell cycle, and energy metabolism. Our recent study of mouse SAD-A identified a unique autoinhibitory sequence (AIS), which binds at the junction of the kinase domain (KD) and the ubiquitin-associated (UBA) domain and exerts autoregulation in cooperation with UBA. Here, we report the crystal structure of the mouse SAD-B C-terminal fragment including the AIS and the kinase-associated domain 1 (KA1) at 2.8 Å resolution. The KA1 domain is structurally conserved, while the isolated AIS sequence is highly flexible and solvent-accessible. Our biochemical studies indicated that the SAD-B AIS exerts the same autoinhibitory role as that in SAD-A. We believe that the flexible isolated AIS sequence is readily available for interaction with KD-UBA and thus inhibits SAD-B activity.

Do Curved Reaching Movements Emerge from Competing Perceptions? A Reply to van der Wel et al. (2009)

ERIC Educational Resources Information Center

Spivey, Michael J.; Dale, Rick; Knoblich, Guenther; Grosjean, Marc

2010-01-01

Spivey, Grosjean, and Knoblich (2005) reported smoothly curved reaching movements, via computer-mouse tracking, which suggested a continuously evolving flow of distributed lexical activation patterns into motor movement during a phonological competitor task. For example, when instructed to click the "candy," participants' mouse-cursor trajectories…

C9orf72 BAC Mouse Model with Motor Deficits and Neurodegenerative Features of ALS/FTD.

PubMed

Liu, Yuanjing; Pattamatta, Amrutha; Zu, Tao; Reid, Tammy; Bardhi, Olgert; Borchelt, David R; Yachnis, Anthony T; Ranum, Laura P W

2016-05-04

To define how the C9orf72 GGGGCC expansion mutation causes ALS/FTD and to facilitate therapy development, a mouse model that recapitulates the molecular and phenotypic features of the disease is urgently needed. Two groups recently reported BAC mouse models that produce RNA foci and RAN proteins but, surprisingly, do not develop the neurodegenerative or behavioral features of ALS/FTD. We now report a BAC mouse model of C9orf72 ALS/FTD that shows decreased survival, paralysis, muscle denervation, motor neuron loss, anxiety-like behavior, and cortical and hippocampal neurodegeneration. These mice express C9orf72 sense transcripts and upregulated antisense transcripts. In contrast to sense RNA foci, antisense foci preferentially accumulate in ALS/FTD-vulnerable cell populations. RAN protein accumulation increases with age and disease, and TDP-43 inclusions are found in degenerating brain regions in end-stage animals. The ALS/FTD phenotypes in our mice provide a unique tool that will facilitate developing therapies targeting pathways that prevent neurodegeneration and increase survival. Copyright © 2016 Elsevier Inc. All rights reserved.

Chimeric elk/mouse prion proteins in transgenic mice.

PubMed

Tamgüney, Gültekin; Giles, Kurt; Oehler, Abby; Johnson, Natrina L; DeArmond, Stephen J; Prusiner, Stanley B

2013-02-01

Chronic wasting disease (CWD) of deer and elk is a highly communicable neurodegenerative disorder caused by prions. Investigations of CWD are hampered by slow bioassays in transgenic (Tg) mice. Towards the development of Tg mice that will be more susceptible to CWD prions, we created a series of chimeric elk/mouse transgenes that encode the N terminus of elk PrP (ElkPrP) up to residue Y168 and the C terminus of mouse PrP (MoPrP) beyond residue 169 (mouse numbering), designated Elk3M(SNIVVK). Between codons 169 and 219, six residues distinguish ElkPrP from MoPrP: N169S, T173N, V183I, I202V, I214V and R219K. Using chimeric elk/mouse PrP constructs, we generated 12 Tg mouse lines and determined incubation times after intracerebral inoculation with the mouse-passaged RML scrapie or Elk1P CWD prions. Unexpectedly, one Tg mouse line expressing Elk3M(SNIVVK) exhibited incubation times of <70 days when inoculated with RML prions; a second line had incubation times of <90 days. In contrast, mice expressing full-length ElkPrP had incubation periods of >250 days for RML prions. Tg(Elk3M,SNIVVK) mice were less susceptible to CWD prions than Tg(ElkPrP) mice. Changing three C-terminal mouse residues (202, 214 and 219) to those of elk doubled the incubation time for mouse RML prions and rendered the mice resistant to Elk1P CWD prions. Mutating an additional two residues from mouse to elk at codons 169 and 173 increased the incubation times for mouse prions to >300 days, but made the mice susceptible to CWD prions. Our findings highlight the role of C-terminal residues in PrP that control the susceptibility and replication of prions.

49 CFR 543.9 - Terminating or modifying an exemption.

Code of Federal Regulations, 2010 CFR

2010-10-01

... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EXEMPTION FROM VEHICLE THEFT PREVENTION... compliance with the parts-marking requirements of part 541 in reducing and deterring motor vehicle theft... exemption has not been as effective as parts-marking in reducing and deterring motor vehicle theft. (2...

Diversification of C. elegans Motor Neuron Identity via Selective Effector Gene Repression.

PubMed

Kerk, Sze Yen; Kratsios, Paschalis; Hart, Michael; Mourao, Romulo; Hobert, Oliver

2017-01-04

A common organizational feature of nervous systems is the existence of groups of neurons that share common traits but can be divided into individual subtypes based on anatomical or molecular features. We elucidate the mechanistic basis of neuronal diversification processes in the context of C.elegans ventral cord motor neurons that share common traits that are directly activated by the terminal selector UNC-3. Diversification of motor neurons into different classes, each characterized by unique patterns of effector gene expression, is controlled by distinct combinations of phylogenetically conserved, class-specific transcriptional repressors. These repressors are continuously required in postmitotic neurons to prevent UNC-3, which is active in all neuron classes, from activating class-specific effector genes in specific motor neuron subsets via discrete cis-regulatory elements. The strategy of antagonizing the activity of broadly acting terminal selectors of neuron identity in a subtype-specific fashion may constitute a general principle of neuron subtype diversification. Copyright © 2017 Elsevier Inc. All rights reserved.

Distribution of vesicular glutamate transporter 1 (VGLUT1) in the mouse esophagus.

PubMed

Kraus, T; Neuhuber, W L; Raab, M

2007-08-01

In rat and mouse esophagus, vesicular glutamate transporter 2 (VGLUT2) has been demonstrated to identify vagal intraganglionic laminar endings (IGLEs); this has recently also been shown for VGLUT1 in rat esophagus. In this study, we have investigated the distribution of VGLUT1 in the mouse esophagus and compared these results with the recently published data from the rat esophagus. Unexpectedly, we have discovered that VGLUT1 mostly fails to identify IGLEs in the mouse esophagus. This is surprising, since the distribution of VGLUT2 shows comparable results in both species. Confocal imaging has revealed substantial colocalization of VGLUT1 immunoreactivity (-ir) with cholinergic and nitrergic/peptidergic markers within the myenteric neuropil and in both cholinergic and nitrergic myenteric neuronal cell bodies. VGLUT1 and cholinergic markers have also been colocalized in fibers of the muscularis mucosae, whereas VGLUT1 and nitrergic markers have never been colocalized in fibers of the muscularis mucosae, although this does occur in fibers of the muscularis running to motor endplates. Thus, VGLUT1 is contained in the nitrergic innervation of mouse esophageal motor endplates, another difference from the rat esophagus. VGLUT1-ir is therefore present in extrinsic and intrinsic innervation of the mouse esophagus, but the significant differences from the rat indicate species variations concerning the distribution of VGLUTs in the peripheral nervous system.

Isl1 is required for multiple aspects of motor neuron development.

PubMed

Liang, Xingqun; Song, Mi-Ryoung; Xu, ZengGuang; Lanuza, Guillermo M; Liu, Yali; Zhuang, Tao; Chen, Yihan; Pfaff, Samuel L; Evans, Sylvia M; Sun, Yunfu

2011-07-01

The LIM homeodomain transcription factor Islet1 (Isl1) is expressed in multiple organs and plays essential roles during embryogenesis. Isl1 is required for the survival and specification of spinal cord motor neurons. Due to early embryonic lethality and loss of motor neurons, the role of Isl1 in other aspects of motor neuron development remains unclear. In this study, we generated Isl1 mutant mouse lines expressing graded doses of Isl1. Our study has revealed essential roles of Isl1 in multiple aspects of motor neuron development, including motor neuron cell body localization, motor column formation and axon growth. In addition, Isl1 is required for survival of cranial ganglia neurons. Copyright © 2011 Elsevier Inc. All rights reserved.

Kinematic markers dissociate error correction from sensorimotor realignment during prism adaptation.

PubMed

O'Shea, Jacinta; Gaveau, Valérie; Kandel, Matthieu; Koga, Kazuo; Susami, Kenji; Prablanc, Claude; Rossetti, Yves

2014-03-01

This study investigated the motor control mechanisms that enable healthy individuals to adapt their pointing movements during prism exposure to a rightward optical shift. In the prism adaptation literature, two processes are typically distinguished. Strategic motor adjustments are thought to drive the pattern of rapid endpoint error correction typically observed during the early stage of prism exposure. This is distinguished from so-called 'true sensorimotor realignment', normally measured with a different pointing task, at the end of prism exposure, which reveals a compensatory leftward 'prism after-effect'. Here, we tested whether each mode of motor compensation - strategic adjustments versus 'true sensorimotor realignment' - could be distinguished, by analyzing patterns of kinematic change during prism exposure. We hypothesized that fast feedforward versus slower feedback error corrective processes would map onto two distinct phases of the reach trajectory. Specifically, we predicted that feedforward adjustments would drive rapid compensation of the initial (acceleration) phase of the reach, resulting in the rapid reduction of endpoint errors typically observed early during prism exposure. By contrast, we expected visual-proprioceptive realignment to unfold more slowly and to reflect feedback influences during the terminal (deceleration) phase of the reach. The results confirmed these hypotheses. Rapid error reduction during the early stage of prism exposure was achieved by trial-by-trial adjustments of the motor plan, which were proportional to the endpoint error feedback from the previous trial. By contrast, compensation of the terminal reach phase unfolded slowly across the duration of prism exposure. Even after 100 trials of pointing through prisms, adaptation was incomplete, with participants continuing to exhibit a small rightward shift in both the reach endpoints and in the terminal phase of reach trajectories. Individual differences in the degree of adaptation of the terminal reach phase predicted the magnitude of prism after-effects. In summary, this study identifies distinct kinematic signatures of fast strategic versus slow sensorimotor realignment processes, which combine to adjust motor performance to compensate for a prismatic shift. © 2013 Elsevier Ltd. All rights reserved.

Comparison of independent screens on differentially vulnerable motor neurons reveals alpha-synuclein as a common modifier in motor neuron diseases

PubMed Central

Kaifer, Kevin A.; Osman, Erkan Y.; Carella, Francesco; Tiberi, Ariana; Ross, Jolill; Pennetta, Giuseppa; Lorson, Christian L.

2017-01-01

The term “motor neuron disease” encompasses a spectrum of disorders in which motor neurons are the primary pathological target. However, in both patients and animal models of these diseases, not all motor neurons are equally vulnerable, in that while some motor neurons are lost very early in disease, others remain comparatively intact, even at late stages. This creates a valuable system to investigate the factors that regulate motor neuron vulnerability. In this study, we aim to use this experimental paradigm to identify potential transcriptional modifiers. We have compared the transcriptome of motor neurons from healthy wild-type mice, which are differentially vulnerable in the childhood motor neuron disease Spinal Muscular Atrophy (SMA), and have identified 910 transcriptional changes. We have compared this data set with published microarray data sets on other differentially vulnerable motor neurons. These neurons were differentially vulnerable in the adult onset motor neuron disease Amyotrophic Lateral Sclerosis (ALS), but the screen was performed on the equivalent population of neurons from neurologically normal human, rat and mouse. This cross species comparison has generated a refined list of differentially expressed genes, including CELF5, Col5a2, PGEMN1, SNCA, Stmn1 and HOXa5, alongside a further enrichment for synaptic and axonal transcripts. As an in vivo validation, we demonstrate that the manipulation of a significant number of these transcripts can modify the neurodegenerative phenotype observed in a Drosophila line carrying an ALS causing mutation. Finally, we demonstrate that vector-mediated expression of alpha-synuclein (SNCA), a transcript decreased in selectively vulnerable motor neurons in all four screens, can extend life span, increase weight and decrease neuromuscular junction pathology in a mouse model of SMA. In summary, we have combined multiple data sets to identify transcripts, which are strong candidates for being phenotypic modifiers, and demonstrated SNCA is a modifier of pathology in motor neuron disease. PMID:28362802

Comparison of independent screens on differentially vulnerable motor neurons reveals alpha-synuclein as a common modifier in motor neuron diseases.

PubMed

Kline, Rachel A; Kaifer, Kevin A; Osman, Erkan Y; Carella, Francesco; Tiberi, Ariana; Ross, Jolill; Pennetta, Giuseppa; Lorson, Christian L; Murray, Lyndsay M

2017-03-01

The term "motor neuron disease" encompasses a spectrum of disorders in which motor neurons are the primary pathological target. However, in both patients and animal models of these diseases, not all motor neurons are equally vulnerable, in that while some motor neurons are lost very early in disease, others remain comparatively intact, even at late stages. This creates a valuable system to investigate the factors that regulate motor neuron vulnerability. In this study, we aim to use this experimental paradigm to identify potential transcriptional modifiers. We have compared the transcriptome of motor neurons from healthy wild-type mice, which are differentially vulnerable in the childhood motor neuron disease Spinal Muscular Atrophy (SMA), and have identified 910 transcriptional changes. We have compared this data set with published microarray data sets on other differentially vulnerable motor neurons. These neurons were differentially vulnerable in the adult onset motor neuron disease Amyotrophic Lateral Sclerosis (ALS), but the screen was performed on the equivalent population of neurons from neurologically normal human, rat and mouse. This cross species comparison has generated a refined list of differentially expressed genes, including CELF5, Col5a2, PGEMN1, SNCA, Stmn1 and HOXa5, alongside a further enrichment for synaptic and axonal transcripts. As an in vivo validation, we demonstrate that the manipulation of a significant number of these transcripts can modify the neurodegenerative phenotype observed in a Drosophila line carrying an ALS causing mutation. Finally, we demonstrate that vector-mediated expression of alpha-synuclein (SNCA), a transcript decreased in selectively vulnerable motor neurons in all four screens, can extend life span, increase weight and decrease neuromuscular junction pathology in a mouse model of SMA. In summary, we have combined multiple data sets to identify transcripts, which are strong candidates for being phenotypic modifiers, and demonstrated SNCA is a modifier of pathology in motor neuron disease.

Early functional impairment of sensory-motor connectivity in a mouse model of spinal muscular atrophy

PubMed Central

Mentis, George Z.; Blivis, Dvir; Liu, Wenfang; Drobac, Estelle; Crowder, Melissa E.; Kong, Lingling; Alvarez, Francisco J.; Sumner, Charlotte J.; O'Donovan, Michael J.

2011-01-01

SUMMARY To define alterations of neuronal connectivity that occur during motor neuron degeneration, we characterized the function and structure of spinal circuitry in spinal muscular atrophy (SMA) model mice. SMA motor neurons show reduced proprioceptive reflexes that correlate with decreased number and function of synapses on motor neuron somata and proximal dendrites. These abnormalities occur at an early stage of disease in motor neurons innervating proximal hindlimb muscles and medial motor neurons innervating axial muscles, but only at end-stage disease in motor neurons innervating distal hindlimb muscles. Motor neuron loss follows afferent synapse loss with the same temporal and topographical pattern. Trichostatin A, which improves motor behavior and survival of SMA mice, partially restores spinal reflexes illustrating the reversibility of these synaptic defects. De-afferentation of motor neurons is an early event in SMA and may be a primary cause of motor dysfunction that is amenable to therapeutic intervention. PMID:21315257

MND2: A new mouse model of inherited motor neuron disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, J.M.; Albin, R.L.; Feldman, E.L.

1993-06-01

The autosomal recessive mutation mnd2 results in early onset motor neuron disease with rapidly progressive paralysis, severe muscle wasting, regression of thymus and spleen, and death before 40 days of age. mnd2 has been mapped to mouse chromosome 6 with the gene order: centromere-Tcrb-Ly-2-Sftp-3-D6Mit4-mnd2-D6Mit6, D6Mit9-D6Rck132-Raf-1, D6Mit11-D6Mit12-D6Mit14. mnd2 is located within a conserved linkage group with homologs on human chromosome 2p12-p13. Spinal motor neurons of homozygous affected animals are swollen and stain weakly, and electromyography revealed spontaneous activity characteristic of muscle denervation. Myelin staining was normal throughout the neuraxis. The clinical observations are consistent with a primary abnormality of lower motormore » neuron function. This new animal model will be of value for identification of a genetic defect responsible for motor neuron disease and for evaluation of new therapies. 36 refs., 7 figs., 2 tabs.« less

Deficits in working memory and motor performance in the APP/PS1ki mouse model for Alzheimer's disease.

PubMed

Wirths, Oliver; Breyhan, Henning; Schäfer, Stephanie; Roth, Christian; Bayer, Thomas A

2008-06-01

The APP/PS1ki mouse model for Alzheimer's disease (AD) exhibits robust brain and spinal cord axonal degeneration and hippocampal CA1 neuron loss starting at 6 months of age. It expresses human mutant APP751 with the Swedish and London mutations together with two FAD-linked knocked-in mutations (PS1 M233T and PS1 L235P) in the murine PS1 gene. The present report covers a phenotypical analysis of this model using either behavioral tests for working memory and motor performance, as well as an analysis of weight development and body shape. At the age of 6 months, a dramatic, age-dependent change in all of these properties and characteristics was observed, accompanied by a significantly reduced ability to perform working memory and motor tasks. The APP/PS1ki mice were smaller and showed development of a thoracolumbar kyphosis, together with an incremental loss of body weight. While 2-month-old APP/PS1ki mice were inconspicuous in all of these tasks and properties, there is a massive age-related impairment in all tested behavioral paradigms. We have previously reported robust axonal degeneration in brain and spinal cord, as well as abundant hippocampal CA1 neuron loss starting at 6 months of age in the APP/PS1ki mouse model, which coincides with the onset of motor and memory deficits described in the present report.

Amelogenin-Ameloblastin Spatial Interaction around Maturing Enamel Rods.

PubMed

Mazumder, P; Prajapati, S; Bapat, R; Moradian-Oldak, J

2016-08-01

Amelogenin and ameloblastin are 2 extracellular matrix proteins that are essential for the proper development of enamel. We recently reported that amelogenin and ameloblastin colocalized during the secretory stage of enamel formation when nucleation of enamel crystallites occurs. Direct interactions between the 2 proteins have been also demonstrated in our in vitro studies. Here, we explore interactions between their fragments during enamel maturation. We applied in vivo immunofluorescence imaging, quantitative co-localization analysis, and a new FRET (fluorescence resonance energy transfer) technique to demonstrate ameloblastin and amelogenin interaction in the maturing mouse enamel. Using immunochemical analysis of protein samples extracted from 8-d-old (P8) first molars from mice as a model for maturation-stage enamel, we identified the ~17-kDa ameloblastin (Ambn-N) and the TRAP (tyrosine-rich amelogenin peptide) fragments. We used Ambn-N18 and Ambn-M300 antibodies raised against the N-terminal and C-terminal segments of ameloblastin, as well as Amel-FL and Amel-C19 antibodies against full-length recombinant mouse amelogenin (rM179) and C-terminal amelogenin, respectively. In transverse sections, co-localization images of N-terminal fragments of amelogenin and ameloblastin around the prism boundary revealed the "fish net" pattern of the enamel matrix. Using in vivo FRET microscopy, we further demonstrated spatial interactions between amelogenin and ameloblastin N-terminal fragments. In the maturing mouse enamel, the association of these residual protein fragments created a discontinuity between enamel rods, which we suggest is important for support and maintenance of enamel rods and eventual contribution to unique enamel mechanical properties. We present data that support cooperative functions of enamel matrix proteins in mediating the structural hierarchy of enamel and that contribute to our efforts to design and develop enamel biomimetic material. © International & American Associations for Dental Research 2016.

Abnormal nuclear envelopes in the striatum and motor deficits in DYT11 myoclonus-dystonia mouse models

PubMed Central

Yokoi, Fumiaki; Dang, Mai T.; Zhou, Tong; Li, Yuqing

2012-01-01

DYT11 myoclonus-dystonia (M-D) is a movement disorder characterized by myoclonic jerks with dystonic symptoms and caused by mutations in paternally expressed SGCE, which codes for ɛ-sarcoglycan. Paternally inherited Sgce heterozygous knock-out (KO) mice exhibit motor deficits and spontaneous myoclonus. Abnormal nuclear envelopes have been reported in cellular and mouse models of early-onset DYT1 generalized torsion dystonia; however, the relationship between the abnormal nuclear envelopes and motor symptoms are not clear. Furthermore, it is not known whether abnormal nuclear envelope exists in non-DYT1 dystonia. In the present study, abnormal nuclear envelopes in the striatal medium spiny neurons (MSNs) were found in Sgce KO mice. To analyze whether the loss of ɛ-sarcoglycan in the striatum alone causes abnormal nuclear envelopes, motor deficits or myoclonus, we produced paternally inherited striatum-specific Sgce conditional KO (Sgce sKO) mice and analyzed their phenotypes. Sgce sKO mice exhibited motor deficits in both beam-walking and accelerated rotarod tests, while they did not exhibit abnormal nuclear envelopes, alteration in locomotion, or myoclonus. The results suggest that the loss of ɛ-sarcoglycan in the striatum contributes to motor deficits, while it alone does not produce abnormal nuclear envelopes or myoclonus. Development of therapies targeting the striatum to compensate for the loss of ɛ-sarcoglycan function may rescue the motor deficits in DYT11 M-D patients. PMID:22080833

Therapeutic effects of dl-3-n-butylphthalide in a transgenic mouse model of amyotrophic lateral sclerosis.

PubMed

Feng, Xin-Hong; Yuan, Wei; Peng, Ying; Liu, Ming-Sheng; Cui, Li-Ying

2012-05-01

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by progressive death of the upper and lower motor neurons. Transgenic mice over-expressing a mutant form of the human SOD1 gene develop an ALS-like phenotype. Currently, there is no effective treatment or drug for the fatal disease. Previous studies reported potent efficacy of dl-3-n-butylphthalide (DL-NBP) for several neurodegenerative disorders and cerebral ischemia. SOD1-G93A mice are a mouse model of ALS. In this study, we investigated the efficacy of DL-NBP on this ALS mouse model. Sixty SOD1-G93A female mice were divided into four groups. The vehicle control group received 0 mg×kg(-1)×d(-1) DL-NBP. The experimental groups received DL-NBP with doses of 30, 60 or 120 mg×kg(-1)×d(-1), respectively. For measurement of motor activity, the hanging wire test and rotarod test were performed. Survival statistics were analyzed by Kaplan-Meier survival curves. The body weight of each mouse was recorded twice per week. The statistical motor unit number estimation (MUNE) technique was used to estimate the number of functioning motor units in gastrocnemius muscle. Muscle morphology was evaluated by hematoxylin and eosin staining. Motor neuron quantitation was performed by Nissl staining and microglia activation was observed by immunohistochemistry. Oral administration of 60 mg×kg(-1)×d(-1)1 DL-NBP significantly prolonged survival ((164.78 ± 16.67) days) of SOD1-G93A mice compared with vehicle control ((140.00 ± 16.89) days). Treating mice with DL-NBP (60 mg×kg(-1)×d(-1)) significantly decreased the progression rate of motor deficits and suppressed body weight reduction. Furthermore, we found that treating SOD1-G93A mice with DL-NBP (60 mg×kg(-1)×d(-1)) slowed the rate of MUNE reduction (P < 0.01). Motor neurons were remarkably preserved in the anterior horns in mice treated with DL-NBP (60 mg×kg(-1)×d(-1)) at the stage of 19 weeks (P < 0.01). Treating mice with DL-NBP (60 mg×kg(-1)×d(-1)) significantly reduced CD11b immunoreactivity compared with vehicle control mice (P < 0.05). No significant effect was observed in mice treated with DL-NBP of 30 or 120 mg×kg(-1)×d(-1). The post-disease-onset administration of DL-NBP significantly prolonged survival and improved motor performance in SOD1-G93A mice. DL-NBP may be a potential therapeutic agent for ALS.

Gamma-aminobutyric acid (GABA) and neuropeptides in neural areas mediating motion-induced emesis

NASA Technical Reports Server (NTRS)

Damelio, F.; Daunton, Nancy G.; Fox, Robert A.

1991-01-01

Immunocytochemical methods were employed to localize the neurotransmitter amino acid gamma-aminobutyric acid and the neuropeptides substance P and Met-enkephalin in the area postrema (AP), area subpostrema (ASP), nucleus of the tractus solitarius (NTS), dorsal motor nucleus of the vagus nerve (DMNV), and lateral vestibular nucleus (LVN). Glutamic acid decarboxylase immunoreactive (GAD-IR) terminals and fibers were observed in the AP and particularly in the ASP. A gradual decrease in the density of terminals was seen towards the solitary complex. The DMNV revealed irregularly scattered GAD-IR terminals within the neuropil or closely surrounding neuronal cell bodies. The LVN, particularly the dorsal division, showed numerous axon terminals which were mostly localize around large neurons and their proximal dendrites. Substance P immunoreactive (SP-IR) terminals and fibers showed high density in the solitary complex, in particular within the lateral division. The ASP showed medium to low density of SP-IR fibers and terminals. The AP exhibited a small number of fibers and terminals irregularly distributed. The DMNV revealed a high density of SP-IR terminals and fibers that were mainly concentrated in the periphery. Very few terminals were detected in the LVN. Met-enkephalin immunoreactive (Met-Enk-IR) fibers and terminals showed high density and uniform distribution in the DMNV. Scattered terminals and fibers were observed in the AP, ASP, and NTS (particularly the lateral division). The very few fibers were observed in the LVN surrounded the neuronal cell bodies. The present report is part of a study designed to investigate the interaction between neuropeptides and conventional neurotransmitters under conditions producing motion sickness and in the process of sensory-motor adaptation.

Altered vesicular glutamate transporter distributions in the mouse cochlear nucleus following cochlear insult

PubMed Central

Heeringa, Amarins N.; Stefanescu, Roxana A.; Raphael, Yehoash; Shore, Susan E.

2015-01-01

Vesicular glutamate transporters 1 and 2 (VGLUT1 and VGLUT2) have distinct distributions in the cochlear nucleus that correspond to the sources of the labeled terminals. VGLUT1 is mainly associated with terminals of auditory nerve fibers, whereas VGLUT2 is mainly associated with glutamatergic terminals deriving from other sources that project to the cochlear nucleus (CN), including somatosensory and vestibular terminals. Previous studies in guinea pig have shown that cochlear damage results in a decrease of VGLUT1-labeled puncta and an increase in VGLUT2-labeled puncta. This indicates cross-modal compensation that is of potential importance in somatic tinnitus. To examine whether this effect is consistent across species and to provide a background for future studies, using transgenesis, the current study examines VGLUT expression profiles upon cochlear insult by intracochlear kanamycin injections in the mouse. Intracochlear kanamycin injections abolished ipsilateral ABR responses in all animals and reduced ipsilateral spiral ganglion neuron densities in animals that were sacrificed after four weeks, but not in animals that were sacrificed after three weeks. In all unilaterally deafened animals, VGLUT1 density was decreased in CN regions that receive auditory nerve fiber terminals, i.e. in the deep layer of the dorsal cochlear nucleus (DCN), in the interstitial region where the auditory nerve enters the CN, and in the magnocellular region of the antero- and posteroventral CN. In contrast, density of VGLUT2 expression was upregulated in the fusiform cell layer of the DCN and in the granule cell lamina, which are known to receive somatosensory and vestibular terminals. These results show that a cochlear insult induces cross-modal compensation in the cochlear nucleus of the mouse, confirming previous findings in guinea pig, and that these changes are not dependent on the occurrence of spiral ganglion neuron degeneration. PMID:26705736

Altered vesicular glutamate transporter distributions in the mouse cochlear nucleus following cochlear insult.

PubMed

Heeringa, A N; Stefanescu, R A; Raphael, Y; Shore, S E

2016-02-19

Vesicular glutamate transporters 1 and 2 (VGLUT1 and VGLUT2) have distinct distributions in the cochlear nucleus that correspond to sources of the labeled terminals. VGLUT1 is mainly associated with terminals of auditory nerve fibers, whereas VGLUT2 is mainly associated with glutamatergic terminals deriving from other sources that project to the cochlear nucleus (CN), including somatosensory and vestibular terminals. Previous studies in guinea pig have shown that cochlear damage results in a decrease of VGLUT1-labeled puncta and an increase in VGLUT2-labeled puncta. This indicates cross-modal compensation that is of potential importance in somatic tinnitus. To examine whether this effect is consistent across species and to provide a background for future studies, using transgenesis, the current study examines VGLUT expression profiles upon cochlear insult by intracochlear kanamycin injections in the mouse. Intracochlear kanamycin injections abolished ipsilateral ABR responses in all animals and reduced ipsilateral spiral ganglion neuron densities in animals that were sacrificed after four weeks, but not in animals that were sacrificed after three weeks. In all unilaterally deafened animals, VGLUT1 density was decreased in CN regions that receive auditory nerve fiber terminals, i.e., in the deep layer of the dorsal cochlear nucleus (DCN), in the interstitial region where the auditory nerve enters the CN, and in the magnocellular region of the antero- and posteroventral CN. In contrast, density of VGLUT2 expression was upregulated in the fusiform cell layer of the DCN and in the granule cell lamina, which are known to receive somatosensory and vestibular terminals. These results show that a cochlear insult induces cross-modal compensation in the cochlear nucleus of the mouse, confirming previous findings in guinea pig, and that these changes are not dependent on the occurrence of spiral ganglion neuron degeneration. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Anthocyanin-rich acai (Euterpe oleracea mart.) fruit pulp fractions attenuate inflammatory stress signaling in mouse brain BV-2 microglial cells

USDA-ARS?s Scientific Manuscript database

Age-related increases in oxidative stress and inflammation are associated with loss of cognitive and motor functions. Previous research has shown that supplementation with berry fruits can modulate signaling in primary hippocampal neurons or BV-2 mouse microglial cells. Because of the high polypheno...

Amino terminus of substance P potentiates kainic acid-induced activity in the mouse spinal cord.

PubMed

Larson, A A; Sun, X

1992-12-01

Sensitization to the behavioral effects produced by repeated injections of kainic acid (KA) into the mouse spinal cord area has been previously shown to be abolished by pretreatment with capsaicin, a neurotoxin of substance P (SP)-containing primary afferent C-fibers. While SP has a variety of well characterized biological actions that are mediated by interactions of its COOH terminus with neurokinin receptors, more recently we have characterized an amino-terminally directed SP binding site. The present studies were initiated to determine whether behavioral sensitization to repeated injections of intrathecally administered KA is mediated by the COOH or NH2 terminal of SP. In the present studies, pretreatment with SP(1-7), an NH2-terminal fragment of SP, but not SP(5-11), a COOH-terminal fragment, potentiated KA-induced behavioral activity in mice. Pretreatment with [D-Pro2,D-Phe7]SP(1-7), an inhibitor of SP NH2-terminal binding, blocked the potentiative effect of SP(1-7) as well as the sensitization to repeated injections of KA. In contrast, [D-Pro2,D-Trp7,9]SP, a neurokinin antagonist, had little effect on behavioral sensitization to KA. The present study suggests that SP has an important modulatory role on excitatory amino acid activity in the spinal cord that is mediated by an action of the NH2 terminal of SP at a non-neurokinin receptor.

Regulation of presynaptic Ca2+, synaptic plasticity and contextual fear conditioning by a N-terminal β-amyloid fragment.

PubMed

Lawrence, James L M; Tong, Mei; Alfulaij, Naghum; Sherrin, Tessi; Contarino, Mark; White, Michael M; Bellinger, Frederick P; Todorovic, Cedomir; Nichols, Robert A

2014-10-22

Soluble β-amyloid has been shown to regulate presynaptic Ca(2+) and synaptic plasticity. In particular, picomolar β-amyloid was found to have an agonist-like action on presynaptic nicotinic receptors and to augment long-term potentiation (LTP) in a manner dependent upon nicotinic receptors. Here, we report that a functional N-terminal domain exists within β-amyloid for its agonist-like activity. This sequence corresponds to a N-terminal fragment generated by the combined action of α- and β-secretases, and resident carboxypeptidase. The N-terminal β-amyloid fragment is present in the brains and CSF of healthy adults as well as in Alzheimer's patients. Unlike full-length β-amyloid, the N-terminal β-amyloid fragment is monomeric and nontoxic. In Ca(2+) imaging studies using a model reconstituted rodent neuroblastoma cell line and isolated mouse nerve terminals, the N-terminal β-amyloid fragment proved to be highly potent and more effective than full-length β-amyloid in its agonist-like action on nicotinic receptors. In addition, the N-terminal β-amyloid fragment augmented theta burst-induced post-tetanic potentiation and LTP in mouse hippocampal slices. The N-terminal fragment also rescued LTP inhibited by elevated levels of full-length β-amyloid. Contextual fear conditioning was also strongly augmented following bilateral injection of N-terminal β-amyloid fragment into the dorsal hippocampi of intact mice. The fragment-induced augmentation of fear conditioning was attenuated by coadministration of nicotinic antagonist. The activity of the N-terminal β-amyloid fragment appears to reside largely in a sequence surrounding a putative metal binding site, YEVHHQ. These findings suggest that the N-terminal β-amyloid fragment may serve as a potent and effective endogenous neuromodulator. Copyright © 2014 the authors 0270-6474/14/3414210-09$15.00/0.

Genes Altered by Intracisternal A Particles in Mouse Mammary Tumorigenesis

DTIC Science & Technology

1997-07-01

mouse Mus musculus as well as most other rodents (1). They are defective retroviruses which contain 3’ and 5’ long terminal repeat (LTR) sequences and... musculus (C57BL/6J) X Mus spretus backcross was obtained for The Jackson Laboratory (Bar Harbor, Maine) and used for localization of the pl7b(kokopelli...understand the nature of the potential mutation found in the tumors I decided to localize pl7b within the mouse genome. I screened a Mus musculus musculus X

The Molecular Basis of Muscular Dystrophy in the mdx Mouse: A Point Mutation

NASA Astrophysics Data System (ADS)

Sicinski, Piotr; Geng, Yan; Ryder-Cook, Allan S.; Barnard, Eric A.; Darlison, Mark G.; Barnard, Pene J.

1989-06-01

The mdx mouse is an X-linked myopathic mutant, an animal model for human Duchenne muscular dystrophy. In both mouse and man the mutations lie within the dystrophin gene, but the phenotypic differences of the disease in the two species confer much interest on the molecular basis of the mdx mutation. The complementary DNA for mouse dystrophin has been cloned, and the sequence has been used in the polymerase chain reaction to amplify normal and mdx dystrophin transcripts in the area of the mdx mutation. Sequence analysis of the amplification products showed that the mdx mouse has a single base substitution within an exon, which causes premature termination of the polypeptide chain.

GIRK Channels Modulate Opioid-Induced Motor Activity in a Cell Type- and Subunit-Dependent Manner

PubMed Central

Kotecki, Lydia; Hearing, Matthew; McCall, Nora M.; Marron Fernandez de Velasco, Ezequiel; Pravetoni, Marco; Arora, Devinder; Victoria, Nicole C.; Munoz, Michaelanne B.; Xia, Zhilian; Slesinger, Paul A.; Weaver, C. David

2015-01-01

G-protein-gated inwardly rectifying K+ (GIRK/Kir3) channel activation underlies key physiological effects of opioids, including analgesia and dependence. GIRK channel activation has also been implicated in the opioid-induced inhibition of midbrain GABA neurons and consequent disinhibition of dopamine (DA) neurons in the ventral tegmental area (VTA). Drug-induced disinhibition of VTA DA neurons has been linked to reward-related behaviors and underlies opioid-induced motor activation. Here, we demonstrate that mouse VTA GABA neurons express a GIRK channel formed by GIRK1 and GIRK2 subunits. Nevertheless, neither constitutive genetic ablation of Girk1 or Girk2, nor the selective ablation of GIRK channels in GABA neurons, diminished morphine-induced motor activity in mice. Moreover, direct activation of GIRK channels in midbrain GABA neurons did not enhance motor activity. In contrast, genetic manipulations that selectively enhanced or suppressed GIRK channel function in midbrain DA neurons correlated with decreased and increased sensitivity, respectively, to the motor-stimulatory effect of systemic morphine. Collectively, these data support the contention that the unique GIRK channel subtype in VTA DA neurons, the GIRK2/GIRK3 heteromer, regulates the sensitivity of the mouse mesolimbic DA system to drugs with addictive potential. PMID:25948263

Expression of a serine protease (motopsin PRSS12) mRNA in the mouse brain: in situ hybridization histochemical study.

PubMed

Iijima, N; Tanaka, M; Mitsui, S; Yamamura, Y; Yamaguchi, N; Ibata, Y

1999-03-20

Serine proteases are considered to play several important roles in the brain. In an attempt to find novel brain-specific serine proteases (BSSPs), motopsin (PRSS-12) was cloned from a mouse brain cDNA library by polymerase chain reaction (PCR). Northern blot analysis demonstrated that the postnatal 10-day mouse brain contained the most amount of motopsin mRNA. At this developmental stage, in situ hybridization histochemistry showed that motopsin mRNA was specifically expressed in the following regions: cerebral cortical layers II/III, V and VIb, endopiriform cortex and the limbic system, particularly in the CA1 region of the hippocampal formation. In addition, in the brainstem, the oculomotor nucleus, trochlear nucleus, mecencephalic and motor nuclei of trigeminal nerve (N), abducens nucleus, facial nucleus, nucleus of the raphe pontis, dorsoral motor nucleus of vagal N, hypoglossal nucleus and ambiguus nucleus showed motopsin mRNA expression. Expression was also found in the anterior horn of the spinal cord. The above findings strongly suggest that neurons in almost all motor nuclei, particularly in the brainstem and spinal cord, express motopsin mRNA, and that motopsin seems to have a close relation to the functional role of efferent neurons. Copyright 1999 Elsevier Science B.V.

Androgens affect muscle, motor neuron, and survival in a mouse model of SOD1-related amyotrophic lateral sclerosis.

PubMed

Aggarwal, Tanya; Polanco, Maria J; Scaramuzzino, Chiara; Rocchi, Anna; Milioto, Carmelo; Emionite, Laura; Ognio, Emanuela; Sambataro, Fabio; Galbiati, Mariarita; Poletti, Angelo; Pennuto, Maria

2014-08-01

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by selective loss of upper and lower motor neurons and skeletal muscle atrophy. Epidemiologic and experimental evidence suggest the involvement of androgens in ALS pathogenesis, but the mechanism through which androgens modify the ALS phenotype is unknown. Here, we show that androgen ablation by surgical castration extends survival and disease duration of a transgenic mouse model of ALS expressing mutant human SOD1 (hSOD1-G93A). Furthermore, long-term treatment of orchiectomized hSOD1-G93A mice with nandrolone decanoate (ND), an anabolic androgenic steroid, worsened disease manifestations. ND treatment induced muscle fiber hypertrophy but caused motor neuron death. ND negatively affected survival, thereby dissociating skeletal muscle pathology from life span in this ALS mouse model. Interestingly, orchiectomy decreased androgen receptor levels in the spinal cord and muscle, whereas ND treatment had the opposite effect. Notably, stimulation with ND promoted the recruitment of endogenous androgen receptor into biochemical complexes that were insoluble in sodium dodecyl sulfate, a finding consistent with protein aggregation. Overall, our results shed light on the role of androgens as modifiers of ALS pathogenesis via dysregulation of androgen receptor homeostasis. Copyright © 2014 Elsevier Inc. All rights reserved.

A novel intermediate in processing of murine leukemia virus envelope glycoproteins. Proteolytic cleavage in the late Golgi region.

PubMed

Bedgood, R M; Stallcup, M R

1992-04-05

The intracellular processing of the murine leukemia virus envelope glycoprotein precursor Pr85 to the mature products gp70 and p15e was analyzed in the mouse T-lymphoma cell line W7MG1. Kinetic (pulse-chase) analysis of synthesis and processing, coupled with endoglycosidase (endo H) and neuraminidase digestions revealed the existence of a novel high molecular weight processing intermediate, gp95, containing endo H-resistant terminally glycosylated oligosaccharide chains. In contrast to previously published conclusions, our data indicate that proteolytic cleavage of the envelope precursor occurs after the acquisition of endo H-resistant chains and terminal glycosylation and thus after the mannosidase II step. In the same W7MG1 cell line, the type and order of murine leukemia virus envelope protein processing events was identical to that for the mouse mammary tumor virus envelope protein. Interestingly, complete mouse mammary tumor virus envelope protein processing requires the addition of glucocorticoid hormone, whereas murine leukemia virus envelope protein processing occurs constitutively in these W7MG1 cells. We propose that all retroviral envelope proteins share a common processing pathway in which proteolytic processing is a late event that follows acquisition of endo H resistance and terminal glycosylation.

Processing of the precursor of protamine P2 in mouse. Peptide mapping and N-terminal sequence analysis of intermediates.

PubMed Central

Carré-Eusèbe, D; Lederer, F; Lê, K H; Elsevier, S M

1991-01-01

Protamine P2, the major basic chromosomal protein of mouse spermatozoa, is synthesized as a precursor almost twice as long as the mature protein, its extra length arising from an N-terminal extension of 44 amino acid residues. This precursor is integrated into chromatin of spermatids, and the extension is processed during chromatin condensation in the haploid cells. We have studied processing in the mouse and have identified two intermediates generated by proteolytic cleavage of the precursor. H.p.l.c. separated protamine P2 from four other spermatid proteins, including the precursor and three proteins known to possess physiological characteristics expected of processing intermediates. Peptide mapping indicated that all of these proteins were structurally similar. Two major proteins were further purified by PAGE, transferred to poly(vinylidene difluoride) membranes and submitted to automated N-terminal sequence analysis. Both sequences were found within the deduced sequence of the precursor extension. The N-terminus of the larger intermediate, PP2C, was Gly-12, whereas the N-terminus of the smaller, PP2D, was His-21. Both processing sites involved a peptide bond in which the carbonyl function was contributed by an acidic amino acid. Images Fig. 1. Fig. 3. Fig. 4. PMID:1854346

A Complete NMR Spectral Assignment of the Lipid-free Mouse Apolipoprotein A-I (ApoAI) C-terminal Truncation Mutant, ApoAI(1-216)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Yunhuang; Hoyt, David W.; Wang, Jianjun

2007-07-28

Apolipoprotein A-I (apoAI) is the major protein component of the high-density lipoprotein (HDL) that has been a hot subject of interests because of its anti-atherogenic properties. Upon lipid-binding, apoAI undergoes conformational changes from lipid-free to several different HDL-associated states (1). These different conformational states regulate HDL formation, maturation and transportation. Recent crystal structure of lipid-free human apoAI represents a major progress of structural study of lipid-free apoAI (2). However, no structural is available for lipid-free mouse apoAI (240-residues). Since mouse HDL is homogenous with only HDL2-like size, whereas human HDL is heterogeneous, containing HDL2/HDL3 as its main species, a structuralmore » comparison between human and mouse apoAI may allow us to identify structure basis of HDL size distribution difference between human and mouse. We carried out an NMR structure determination of lipid-free mouse apoAI (1-216) and completely assigned backbone atoms (except backbone amide proton and nitrogen atoms for residues D1, N48, W107, K108, K132, E135, F147, R148, M169 and K203). Secondary structure prediction using backbone NMR parameters indicates that lipid-free mouse apoAI consists of a four helical segments in the N-terminal domain, residues 1-180. In addition, two short helices are also observed between residues 190-195 and 210-215. The helix locations are significantly different from those in the crystal structure of human apoAI, suggesting that mouse apoAI may have a different conformational adaptation upon lipid-binding. BMRB deposit with accession number: 15091.« less

Induction motor speed control using varied duty cycle terminal voltage via PI controller

NASA Astrophysics Data System (ADS)

Azwin, A.; Ahmed, S.

2018-03-01

This paper deals with the PI speed controller for the three-phase induction motor using PWM technique. The PWM generated signal is utilized for voltage source inverter with an optimal duty cycle on a simplified induction motor model. A control algorithm for generating PWM control signal is developed. Obtained results shows that the steady state error and overshoot of the developed system is in the limit under different speed and load condition. The robustness of the control performance would be potential for induction motor performance improvement.

Rocket nozzle thermal shock tests in an arc heater facility

NASA Technical Reports Server (NTRS)

Painter, James H.; Williamson, Ronald A.

1986-01-01

A rocket motor nozzle thermal structural test technique that utilizes arc heated nitrogen to simulate a motor burn was developed. The technique was used to test four heavily instrumented full-scale Star 48 rocket motor 2D carbon/carbon segments at conditions simulating the predicted thermal-structural environment. All four nozzles survived the tests without catastrophic or other structural failures. The test technique demonstrated promise as a low cost, controllable alternative to rocket motor firing. The technique includes the capability of rapid termination in the event of failure, allowing post-test analysis.

Study on Enhanceing Mechanisim and Policy on Energy Efficiency of Electrical Motor System in China

NASA Astrophysics Data System (ADS)

Liu, Ren; Zhao, Yuejin; Liu, Meng; Chen, Lili; Yang, Ming

2017-12-01

Motor is a kind of terminal energy-consumption equipment with the maximum power consumption in China every year; compared with international advanced level, the technical innovation of motor equipment, speed regulating system, drive system and automatic intelligent control technique in China still lag behind relatively; the standard technical service support system of motor system is not complete, the energy conserving transformation mode needs to be innovated, and the market development mechanism of motor industry is not perfect, etc. This paper analyzes the promotion mechanism and policy on energy efficiency of the motor system in China in recent years, studies the demonstration cases of successful promotion of high-efficiency motor, standard labeling, financial finance and tax policy, and puts forward suggestions on promotion of high-efficiency motor in China.

Position and speed control of brushless DC motors using sensorless techniques and application trends.

PubMed

Gamazo-Real, José Carlos; Vázquez-Sánchez, Ernesto; Gómez-Gil, Jaime

2010-01-01

This paper provides a technical review of position and speed sensorless methods for controlling Brushless Direct Current (BLDC) motor drives, including the background analysis using sensors, limitations and advances. The performance and reliability of BLDC motor drivers have been improved because the conventional control and sensing techniques have been improved through sensorless technology. Then, in this paper sensorless advances are reviewed and recent developments in this area are introduced with their inherent advantages and drawbacks, including the analysis of practical implementation issues and applications. The study includes a deep overview of state-of-the-art back-EMF sensing methods, which includes Terminal Voltage Sensing, Third Harmonic Voltage Integration, Terminal Current Sensing, Back-EMF Integration and PWM strategies. Also, the most relevant techniques based on estimation and models are briefly analysed, such as Sliding-mode Observer, Extended Kalman Filter, Model Reference Adaptive System, Adaptive observers (Full-order and Pseudoreduced-order) and Artificial Neural Networks.

Shuttle Rocket Motor Program: NASA should delay awarding some construction contracts. Report to the Chair, Subcommittee on Government Activities and Transportation, Committee on Government Operations, House of Representatives

NASA Technical Reports Server (NTRS)

1992-01-01

Even though the executive branch has proposed terminating the Advanced Solid Rocket Motor (ASRM) program, NASA is proceeding with all construction activity planned for FY 1992 to avoid schedule slippage if the program is reinstated by Congress. However, NASA could delay some construction activities for at least a few months without affecting the current launch data schedule. For example, NASA could delay Yellow Creek's motor storage and dock projects, Stennis' dock project, and Kennedy's rotation processing and surge facility and dock projects. Starting all construction activities as originally planned could result in unnecessarily incurring additional costs and termination liability if the funding for FY 1993 is not provided. If Congress decides to continue the program, construction could still be completed in time to avoid schedule slippage.

Increased cholecystokinin labeling in the hippocampus of a mouse model of epilepsy maps to spines and glutamatergic terminals

PubMed Central

Wyeth, Megan S.; Zhang, Nianhui; Houser, Carolyn R.

2011-01-01

The neuropeptide cholecystokinin (CCK) is abundant in the central nervous system and expressed in a subset of inhibitory interneurons, particularly in their axon terminals. The expression profile of CCK undergoes numerous changes in several models of temporal lobe epilepsy. Previous studies in the pilocarpine model of epilepsy have shown that CCK immunohistochemical labeling is substantially reduced in several regions of the hippocampal formation, consistent with decreased CCK expression as well as selective neuronal degeneration. However, in a mouse pilocarpine model of recurrent seizures, increases in CCK-labeling also occur and are especially striking in the hippocampal dendritic layers of strata oriens and radiatum. Characterizing these changes and determining the cellular basis of the increased labeling were the major goals of the current study. One possibility was that the enhanced CCK labeling could be associated with an increase in GABAergic terminals within these regions. However, in contrast to the marked increase in CCK-labeled structures, labeling of GABAergic axon terminals was decreased in the dendritic layers. Likewise, cannabinoid receptor 1-labeled axon terminals, many of which are CCK-containing GABAergic terminals, were also decreased. These findings suggested that the enhanced CCK labeling was not due to an increase in GABAergic axon terminals. The subcellular localization of CCK immunoreactivity was then examined using electron microscopy, and the identities of the structures that formed synaptic contacts were determined. In pilocarpine-treated mice, CCK was observed in dendritic spines and these were proportionally increased relative to controls, whereas the proportion of CCK-labeled terminals forming symmetric synapses was decreased. In addition, CCK-positive axon terminals forming asymmetric synapses were readily observed in these mice. Double labeling with vesicular glutamate transporter 1 and CCK revealed co-localization in numerous terminals forming asymmetric synapses, confirming the glutamatergic identity of these terminals. These data raise the possibility that expression of CCK is increased in hippocampal pyramidal cells in mice with recurrent, spontaneous seizures. PMID:22155653

Fraser syndrome and mouse blebbed phenotype caused by mutations in FRAS1/Fras1 encoding a putative extracellular matrix protein.

PubMed

McGregor, Lesley; Makela, Ville; Darling, Susan M; Vrontou, Sofia; Chalepakis, Georges; Roberts, Catherine; Smart, Nicola; Rutland, Paul; Prescott, Natalie; Hopkins, Jason; Bentley, Elizabeth; Shaw, Alison; Roberts, Emma; Mueller, Robert; Jadeja, Shalini; Philip, Nicole; Nelson, John; Francannet, Christine; Perez-Aytes, Antonio; Megarbane, Andre; Kerr, Bronwyn; Wainwright, Brandon; Woolf, Adrian S; Winter, Robin M; Scambler, Peter J

2003-06-01

Fraser syndrome (OMIM 219000) is a multisystem malformation usually comprising cryptophthalmos, syndactyly and renal defects. Here we report autozygosity mapping and show that the locus FS1 at chromosome 4q21 is associated with Fraser syndrome, although the condition is genetically heterogeneous. Mutation analysis identified five frameshift mutations in FRAS1, which encodes one member of a family of novel proteins related to an extracellular matrix (ECM) blastocoelar protein found in sea urchin. The FRAS1 protein contains a series of N-terminal cysteine-rich repeat motifs previously implicated in BMP metabolism, suggesting that it has a role in both structure and signal propagation in the ECM. It has been speculated that Fraser syndrome is a human equivalent of the blebbed phenotype in the mouse, which has been associated with mutations in at least five loci including bl. As mapping data were consistent with homology of FRAS1 and bl, we screened DNA from bl/bl mice and identified a premature termination of mouse Fras1. Thus, the bl mouse is a model for Fraser syndrome in humans, a disorder caused by disrupted epithelial integrity in utero.

The Peptide Near the C Terminus Regulates Receptor CAR Nuclear Translocation Induced by Xenochemicals in Mouse Liver

PubMed Central

Zelko, Igor; Sueyoshi, Tatsuya; Kawamoto, Takeshi; Moore, Rick; Negishi, Masahiko

2001-01-01

In response to phenobarbital (PB) and other PB-type inducers, the nuclear receptor CAR translocates to the mouse liver nucleus (T. Kawamoto et al., Mol. Cell. Biol. 19:6318–6322, 1999). To define the translocation mechanism, fluorescent protein-tagged human CAR (hCAR) was expressed in the mouse livers using the in situ DNA injection and gene delivery systems. As in the wild-type hCAR, the truncated receptor lacking the C-terminal 10 residues (i.e., AF2 domain) translocated to the nucleus, indicating that the PB-inducible translocation is AF2 independent. Deletion of the 30 C-terminal residues abolished the receptor translocation, and subsequent site-directed mutagenesis delineated the PB-inducible translocation activity of the receptor to the peptide L313GLL316AEL319. Ala mutations of Leu313, Leu316, or Leu319 abrogated the translocation of CAR in the livers, while those of Leu312 or Leu315 did not affect the nuclear translocation. The leucine-rich peptide dictates the nuclear translocation of hCAR in response to various PB-type inducers and appears to be conserved in the mouse and rat receptors. PMID:11283262

GATA1 and PU.1 Bind to Ribosomal Protein Genes in Erythroid Cells: Implications for Ribosomopathies

PubMed Central

Amanatiadou, Elsa P.; Papadopoulos, Giorgio L.; Strouboulis, John; Vizirianakis, Ioannis S.

2015-01-01

The clear connection between ribosome biogenesis dysfunction and specific hematopoiesis-related disorders prompted us to examine the role of critical lineage-specific transcription factors in the transcriptional regulation of ribosomal protein (RP) genes during terminal erythroid differentiation. By applying EMSA and ChIP methodologies in mouse erythroleukemia cells we show that GATA1 and PU.1 bind in vitro and in vivo the proximal promoter region of the RPS19 gene which is frequently mutated in Diamond-Blackfan Anemia. Moreover, ChIPseq data analysis also demonstrates that several RP genes are enriched as potential GATA1 and PU.1 gene targets in mouse and human erythroid cells, with GATA1 binding showing an association with higher ribosomal protein gene expression levels during terminal erythroid differentiation in human and mouse. Our results suggest that RP gene expression and hence balanced ribosome biosynthesis may be specifically and selectively regulated by lineage specific transcription factors during hematopoiesis, a finding which may be clinically relevant to ribosomopathies. PMID:26447946

Hypoexcitability precedes denervation in the large fast-contracting motor units in two unrelated mouse models of ALS

PubMed Central

Martínez-Silva, María de Lourdes; Imhoff-Manuel, Rebecca D; Sharma, Aarti; Heckman, CJ; Shneider, Neil A; Roselli, Francesco; Zytnicki, Daniel

2018-01-01

Hyperexcitability has been suggested to contribute to motoneuron degeneration in amyotrophic lateral sclerosis (ALS). If this is so, and given that the physiological type of a motor unit determines the relative susceptibility of its motoneuron in ALS, then one would expect the most vulnerable motoneurons to display the strongest hyperexcitability prior to their degeneration, whereas the less vulnerable should display a moderate hyperexcitability, if any. We tested this hypothesis in vivo in two unrelated ALS mouse models by correlating the electrical properties of motoneurons with their physiological types, identified based on their motor unit contractile properties. We found that, far from being hyperexcitable, the most vulnerable motoneurons become unable to fire repetitively despite the fact that their neuromuscular junctions were still functional. Disease markers confirm that this loss of function is an early sign of degeneration. Our results indicate that intrinsic hyperexcitability is unlikely to be the cause of motoneuron degeneration. PMID:29580378

Transformation of Cortex-wide Emergent Properties during Motor Learning.

PubMed

Makino, Hiroshi; Ren, Chi; Liu, Haixin; Kim, An Na; Kondapaneni, Neehar; Liu, Xin; Kuzum, Duygu; Komiyama, Takaki

2017-05-17

Learning involves a transformation of brain-wide operation dynamics. However, our understanding of learning-related changes in macroscopic dynamics is limited. Here, we monitored cortex-wide activity of the mouse brain using wide-field calcium imaging while the mouse learned a motor task over weeks. Over learning, the sequential activity across cortical modules became temporally more compressed, and its trial-by-trial variability decreased. Moreover, a new flow of activity emerged during learning, originating from premotor cortex (M2), and M2 became predictive of the activity of many other modules. Inactivation experiments showed that M2 is critical for the post-learning dynamics in the cortex-wide activity. Furthermore, two-photon calcium imaging revealed that M2 ensemble activity also showed earlier activity onset and reduced variability with learning, which was accompanied by changes in the activity-movement relationship. These results reveal newly emergent properties of macroscopic cortical dynamics during motor learning and highlight the importance of M2 in controlling learned movements. Copyright © 2017 Elsevier Inc. All rights reserved.

Suppression of the motor deficit in a mucolipidosis type IV mouse model by bone marrow transplantation

PubMed Central

Walker, Marquis T.; Montell, Craig

2016-01-01

Mucolipidosis IV (MLIV) is a severe lysosomal storage disorder, which results from loss of the TRPML1 channel. MLIV causes multiple impairments in young children, including severe motor deficits. Currently, there is no effective treatment. Using a Drosophila MLIV model, we showed previously that introduction of trpml+ in phagocytic glia rescued the locomotor deficit by removing early dying neurons, thereby preventing amplification of neuronal death from cytotoxicity. Because microglia, which are phagocytic cells in the mammalian brain, are bone marrow derived, and cross the blood–brain barrier, we used a mouse MLIV model to test the efficacy of bone marrow transplantation (BMT). We found that BMT suppressed the reduced myelination and the increased caspase-3 activity due to loss of TRPML1. Using a rotarod test, we demonstrated that early BMT greatly delayed the motor impairment in the mutant mice. These data offer the possibility that BMT might provide the first therapy for MLIV. PMID:27270598

Discovery of a Novel Class of Survival Motor Neuron 2 Splicing Modifiers for the Treatment of Spinal Muscular Atrophy.

PubMed

Pinard, Emmanuel; Green, Luke; Reutlinger, Michael; Weetall, Marla; Naryshkin, Nikolai A; Baird, John; Chen, Karen S; Paushkin, Sergey V; Metzger, Friedrich; Ratni, Hasane

2017-05-25

Spinal muscular atrophy (SMA) is caused by mutation or deletion of the survival motor neuron 1 (SMN1) gene, resulting in low levels of functional SMN protein. We have reported recently the identification of small molecules (coumarins, iso-coumarins and pyrido-pyrimidinones) that modify the alternative splicing of SMN2, a paralogous gene to SMN1, restoring the survival motor neuron (SMN) protein level in mouse models of SMA. Herein, we report our efforts to identify a novel chemotype as one strategy to potentially circumvent safety concerns from earlier derivatives such as in vitro phototoxicity and in vitro mutagenicity associated with compounds 1 and 2 or the in vivo retinal findings observed in a long-term chronic tox study with 3 at high exposures only. Optimized representative compounds modify the alternative splicing of SMN2, increase the production of full length SMN2 mRNA, and therefore levels of full length SMN protein upon oral administration in two mouse models of SMA.

Axon terminals expressing vesicular glutamate transporter VGLUT1 or VGLUT2 within the trigeminal motor nucleus of the rat: origins and distribution patterns.

PubMed

Pang, You-Wang; Ge, Shun-Nan; Nakamura, Kouichi C; Li, Jin-Lian; Xiong, Kang-Hui; Kaneko, Takeshi; Mizuno, Noboru

2009-02-10

Little is known about the significance of the two types of glutamatergic neurons (those expressing vesicular glutamate transporter VGLUT1 or VGLUT2) in the control of jaw movements. We thus examined the origin and distribution of axon terminals with VGLUT1 or VGLUT2 immunoreactivity within the trigeminal motor nucleus (Vm) in the rat. The Vm was divided into the dorsolateral division (Vm.dl; jaw-closing motoneuron pool) and the ventromedial division (Vm.vm; jaw-opening motoneuron pool). VGLUT1-immunopositive terminals were seen within the Vm.dl only, whereas VGLUT2-immunopositive ones were distributed to both the Vm.dl and the Vm.vm. Transection of the motor root eliminated almost all VGLUT1-immunopositive axons in the Vm.dl, with no changes of VGLUT2 immunoreactivity in the two divisions, indicating that the VGLUT1- and VGLUT2-immunopositive axons came from primary afferents in the mesencephalic trigeminal nucleus and premotor neurons for the Vm, respectively. In situ hybridization histochemistry revealed that VGLUT2 neurons were much more numerous than VGLUT1 neurons in the regions corresponding to the reported premotoneuron pool for the Vm. The results of immunofluorescence labeling combined with anterograde tract tracing further indicated that premotor neurons with VGLUT2 in the trigeminal sensory nuclei, the supratrigeminal region, and the reticular region ventral to the Vm sent axon terminals contacting trigeminal motoneurons and that some of the VGLUT1-expressing premotor neurons in the reticular region ventral to the Vm sent axon terminals to jaw-closing motoneurons. The present results suggested that the roles played by glutamatergic neurons in controlling jaw movements might be different between VGLUT1- and VGLUT2-expressing neurons.

Mouse Models of Autism: Testing Hypotheses About Molecular Mechanisms

PubMed Central

2012-01-01

Autism is a neurodevelopmental disorder that is currently diagnosed by the presence of three behavioral criteria (1) qualitative impairments in reciprocal social interactions, (2) deficits in communication, including delayed language and noninteractive conversation, and (3) motor stereotypies, repetitive behaviors, insistence on sameness, and restricted interests. This chapter describes analogous behavioral assays that have been developed for mice, including tests for social approach, reciprocal social interactions, olfactory communication, ultrasonic vocalizations, repetitive and perseverative behaviors, and motor stereotypies. Examples of assay applications to genetic mouse models of autism are provided. Robust endophenotypes that are highly relevant to the core symptoms of autism are enabling the search for the genetic and environmental causes of autism, and the discovery of effective treatments. PMID:21225409

Bayesian analysis of the kinetics of quantal transmitter secretion at the neuromuscular junction.

PubMed

Saveliev, Anatoly; Khuzakhmetova, Venera; Samigullin, Dmitry; Skorinkin, Andrey; Kovyazina, Irina; Nikolsky, Eugeny; Bukharaeva, Ellya

2015-10-01

The timing of transmitter release from nerve endings is considered nowadays as one of the factors determining the plasticity and efficacy of synaptic transmission. In the neuromuscular junction, the moments of release of individual acetylcholine quanta are related to the synaptic delays of uniquantal endplate currents recorded under conditions of lowered extracellular calcium. Using Bayesian modelling, we performed a statistical analysis of synaptic delays in mouse neuromuscular junction with different patterns of rhythmic nerve stimulation and when the entry of calcium ions into the nerve terminal was modified. We have obtained a statistical model of the release timing which is represented as the summation of two independent statistical distributions. The first of these is the exponentially modified Gaussian distribution. The mixture of normal and exponential components in this distribution can be interpreted as a two-stage mechanism of early and late periods of phasic synchronous secretion. The parameters of this distribution depend on both the stimulation frequency of the motor nerve and the calcium ions' entry conditions. The second distribution was modelled as quasi-uniform, with parameters independent of nerve stimulation frequency and calcium entry. Two different probability density functions for the distribution of synaptic delays suggest at least two independent processes controlling the time course of secretion, one of them potentially involving two stages. The relative contribution of these processes to the total number of mediator quanta released depends differently on the motor nerve stimulation pattern and on calcium ion entry into nerve endings.

How does environmental enrichment reduce repetitive motor behaviors? Neuronal activation and dendritic morphology in the indirect basal ganglia pathway of a mouse model

PubMed Central

Bechard, Allison R.; Cacodcar, Nadia; King, Michael A.; Lewis, Mark H.

2015-01-01

Repetitive motor behaviors are observed in many neurodevelopmental and neurological disorders (e.g. autism spectrum disorders, Tourette syndrome, fronto-temporal dementia). Despite their clinical importance, the neurobiology underlying these highly stereotyped, apparently functionless behaviors is poorly understood. Identification of mechanisms that mediate the development of repetitive behaviors will aid in the discovery of new therapeutic targets and treatment development. Using a deer mouse model, we have shown that decreased indirect basal ganglia pathway activity is associated with high levels of repetitive behavior. Environmental enrichment (EE) markedly attenuates the development of such aberrant behaviors in mice, although mechanisms driving this effect are unknown. We hypothesized that EE would reduce repetitive motor behaviors by increasing indirect basal ganglia pathway function. We assessed neuronal activation and dendritic spine density in basal ganglia of adult deer mice reared in EE and standard housing. Significant increases in neuronal activation and dendritic spine densities were observed only in the subthalamic nucleus (STN) and globus pallidus (GP), and only for those mice that exhibited an EE-induced decrease in repetitive motor behavior. As the STN and GP lie within the indirect pathway, these data suggest that EE-induced attenuation of repetitive motor behaviors is associated with increased functional activation of the indirect basal ganglia pathway. These results are consistent with our other findings highlighting the importance of the indirect pathway in mediating repetitive motor behaviors. PMID:26620495

Nuclear Condensation during Mouse Erythropoiesis Requires Caspase-3-Mediated Nuclear Opening.

PubMed

Zhao, Baobing; Mei, Yang; Schipma, Matthew J; Roth, Eric Wayne; Bleher, Reiner; Rappoport, Joshua Z; Wickrema, Amittha; Yang, Jing; Ji, Peng

2016-03-07

Mammalian erythropoiesis involves chromatin condensation that is initiated in the early stage of terminal differentiation. The mechanisms of chromatin condensation during erythropoiesis are unclear. Here, we show that the mouse erythroblast forms large, transient, and recurrent nuclear openings that coincide with the condensation process. The opening lacks nuclear lamina, nuclear pore complexes, and nuclear membrane, but it is distinct from nuclear envelope changes that occur during apoptosis and mitosis. A fraction of the major histones are released from the nuclear opening and degraded in the cytoplasm. We demonstrate that caspase-3 is required for the nuclear opening formation throughout terminal erythropoiesis. Loss of caspase-3 or ectopic expression of a caspase-3 non-cleavable lamin B mutant blocks nuclear opening formation, histone release, chromatin condensation, and terminal erythroid differentiation. We conclude that caspase-3-mediated nuclear opening formation accompanied by histone release from the opening is a critical step toward chromatin condensation during erythropoiesis in mice. Copyright © 2016 Elsevier Inc. All rights reserved.

Nuclear condensation during mouse erythropoiesis requires caspase-3-mediated nuclear opening

PubMed Central

Zhao, Baobing; Mei, Yang; Schipma, Matthew J; Roth, Eric Wayne; Bleher, Reiner; Rappoport, Joshua Z.; Wickrema, Amittha; Yang, Jing; Ji, Peng

2016-01-01

SUMMARY Mammalian erythropoiesis involves chromatin condensation that is initiated in the early stage of terminal differentiation. The mechanisms of chromatin condensation during erythropoiesis are unclear. Here, we show that the mouse erythroblast forms large, transient, and recurrent nuclear openings that coincide with the condensation process. The opening lacks nuclear lamina, nuclear pore complexes, and nuclear membrane, but it is distinct from nuclear envelope changes that occur during apoptosis and mitosis. A fraction of the major histones are released from the nuclear opening and degraded in the cytoplasm. We demonstrate that caspase-3 is required for the nuclear opening formation throughout terminal erythropoiesis. Loss of caspase-3 or ectopic expression of a caspase-3 non-cleavable lamin B mutant blocks nuclear opening formation, histone release, chromatin condensation, and terminal erythroid differentiation. We conclude that caspase-3-mediated nuclear opening formation accompanied by histone release from the opening is a critical step towards chromatin condensation during erythropoiesis in mice. PMID:26954545

The neuropathology observed in wild-type mice inoculated with human poliovirus mirrors human paralytic poliomyelitis.

PubMed

Ford, Dayton J; Ropka, Stacie L; Collins, George H; Jubelt, Burk

2002-09-01

Human paralytic poliomyelitis results from the destruction of spinal cord anterior horn motor neurons by human poliovirus (PV). CNS disease pathology similar to human poliomyelitis has been observed in experimentally infected chimpanzees, monkeys and wild-type mice. In this study we present a detailed examination of the clinical and histopathological features in the wild-type mouse after intracranial (i.c.) and novel intramuscular (i.m.) injection of poliovirus. Either route of poliovirus administration results in a clinical disease characterized predominately by flaccid paralysis. The observed histopathological features are compared with the histopathology reported for human paralytic poliomyelitis, experimentally infected chimpanzees, monkeys and transgenic mice expressing the human poliovirus receptor (hPVR). The observation of flaccid paralysis and anterior horn motor neuron destruction mirrors what is observed in human paralytic poliomyelitis. Our results suggest that the neuropathology observed in the wild-type mouse model is similar to what has been observed in both the human disease and in other experimental animal models, with the possible exception of the transgenic mouse model. The observed neuropathology of the wild-type mouse model more closely reflects what has been observed in human poliomyelitis, as well as in experimentally infected chimpanzees and monkeys, than does the hPVR transgenic mouse model. The previously reported poliovirus-induced white matter demyelinating disease was not observed.

Homopolar Transformer for Conversion of Electrical Energy

DTIC Science & Technology

1998-10-13

electrical current Hows through a conductor situated in a magnetic field during rotation of the machine rotor. In L the case of a homopolar motor ...10, incorporated within a homopolar machine 12 corresponding for example to the motor or generator disclosed in U.S. Pat. No. 3,657,580 to Doyle. The...During operation of the homopolar machine 12 as a motor , a voltage source 16 connected to the stator terminals 26 and 28 causes a current to flow

Homopolar Transformer for Conversion of Electrical Energy

DTIC Science & Technology

1997-08-14

machine rotor. In the case of a 14 homopolar motor , the current will develop a force perpendicular to the direction of its flow 15 through the conductor...reference numeral 10, incorporated within a homopolar 14 machine 12 corresponding for example to the motor or generator disclosed in U.S. Patent No...current flow. During 3 operation of the homopolar machine 12 as a motor , a voltage source 16 connected to the stator 5 terminals 26 and 28 causes a

Mouse Hepatitis Virus Strain A59 and Blocking Antireceptor Monoclonal Antibody Bind to the N-Terminal Domain of Cellular Receptor

NASA Astrophysics Data System (ADS)

Dveksler, Gabriela S.; Pensiero, Michael N.; Dieffenbach, Carl W.; Cardellichio, Christine B.; Basile, Alexis A.; Elia, Patrick E.; Holmes, Kathryn V.

1993-03-01

Mouse hepatitis virus (MHV) strain A59 uses as cellular receptors members of the carcinoembryonic antigen family in the immunoglobulin superfamily. Recombinant receptor proteins with deletions of whole or partial immunoglobulin domains were used to identify the regions of receptor glycoprotein recognized by virus and by antireceptor monoclonal antibody CC1, which blocks infection of murine cells. Monoclonal antibody CC1 and MHV-A59 virions bound only to recombinant proteins containing the entire first domain of MHV receptor. To determine which of the proteins could serve as functional virus receptors, receptor-negative hamster cells were transfected with recombinant deletion clones and then challenged with MHV-A59 virions. Receptor activity required the entire N-terminal domain with either the second or the fourth domain and the transmembrane and cytoplasmic domains. Recombinant proteins lacking the first domain or its C-terminal portion did not serve as viral receptors. Thus, like other virus receptors in the immunoglobulin superfamily, including CD4, poliovirus receptor, and intercellular adhesion molecule 1, the N-terminal domain of MHV receptor is recognized by the virus and the blocking monoclonal antibody.

Miro's N-Terminal GTPase Domain Is Required for Transport of Mitochondria into Axons and Dendrites

PubMed Central

Babic, Milos; Russo, Gary J.; Wellington, Andrea J.; Sangston, Ryan M.; Gonzalez, Migdalia

2015-01-01

Mitochondria are dynamically transported in and out of neuronal processes to maintain neuronal excitability and synaptic function. In higher eukaryotes, the mitochondrial GTPase Miro binds Milton/TRAK adaptor proteins linking microtubule motors to mitochondria. Here we show that Drosophila Miro (dMiro), which has previously been shown to be required for kinesin-driven axonal transport, is also critically required for the dynein-driven distribution of mitochondria into dendrites. In addition, we used the loss-of-function mutations dMiroT25N and dMiroT460N to determine the significance of dMiro's N-terminal and C-terminal GTPase domains, respectively. Expression of dMiroT25N in the absence of endogenous dMiro caused premature lethality and arrested development at a pupal stage. dMiroT25N accumulated mitochondria in the soma of larval motor and sensory neurons, and prevented their kinesin-dependent and dynein-dependent distribution into axons and dendrites, respectively. dMiroT25N mutant mitochondria also were severely fragmented and exhibited reduced kinesin and dynein motility in axons. In contrast, dMiroT460N did not impair viability, mitochondrial size, or the distribution of mitochondria. However, dMiroT460N reduced dynein motility during retrograde mitochondrial transport in axons. Finally, we show that substitutions analogous to the constitutively active Ras-G12V mutation in dMiro's N-terminal and C-terminal GTPase domains cause neomorphic phenotypic effects that are likely unrelated to the normal function of each GTPase domain. Overall, our analysis indicates that dMiro's N-terminal GTPase domain is critically required for viability, mitochondrial size, and the distribution of mitochondria out of the neuronal soma regardless of the employed motor, likely by promoting the transition from a stationary to a motile state. PMID:25855186

C-terminal sequence of amyloid-resistant type F apolipoprotein A-II inhibits amyloid fibril formation of apolipoprotein A-II in mice

PubMed Central

Sawashita, Jinko; Zhang, Beiru; Hasegawa, Kazuhiro; Mori, Masayuki; Naiki, Hironobu; Kametani, Fuyuki; Higuchi, Keiichi

2015-01-01

In murine senile amyloidosis, misfolded serum apolipoprotein (apo) A-II deposits as amyloid fibrils (AApoAII) in a process associated with aging. Mouse strains carrying type C apoA-II (APOA2C) protein exhibit a high incidence of severe systemic amyloidosis. Previously, we showed that N- and C-terminal sequences of apoA-II protein are critical for polymerization into amyloid fibrils in vitro. Here, we demonstrate that congenic mouse strains carrying type F apoA-II (APOA2F) protein, which contains four amino acid substitutions in the amyloidogenic regions of APOA2C, were absolutely resistant to amyloidosis, even after induction of amyloidosis by injection of AApoAII. In vitro fibril formation tests showed that N- and C-terminal APOA2F peptides did not polymerize into amyloid fibrils. Moreover, a C-terminal APOA2F peptide was a strong inhibitor of nucleation and extension of amyloid fibrils during polymerization. Importantly, after the induction of amyloidosis, we succeeded in suppressing amyloid deposition in senile amyloidosis-susceptible mice by treatment with the C-terminal APOA2F peptide. We suggest that the C-terminal APOA2F peptide might inhibit further extension of amyloid fibrils by blocking the active ends of nuclei (seeds). We present a previously unidentified model system for investigating inhibitory mechanisms against amyloidosis in vivo and in vitro and believe that this system will be useful for the development of novel therapies. PMID:25675489

Blocking of proteolytic processing and deletion of glycosaminoglycan side chain of mouse DMP1 by substituting critical amino acid residues.

PubMed

Peng, Tao; Huang, Bingzhen; Sun, Yao; Lu, Yongbo; Bonewald, Lynda; Chen, Shuo; Butler, William T; Feng, Jerry Q; D'Souza, Rena N; Qin, Chunlin

2009-01-01

Dentin matrix protein 1 (DMP1) is present in the extracellular matrix (ECM) of dentin and bone as processed NH(2)- and COOH-terminal fragments, resulting from proteolytic cleavage at the NH(2) termini of 4 aspartic acid residues during rat DMP1 processing. One cleavage site residue, Asp(181) (corresponding to Asp(197) of mouse DMP1), and its flanking region are highly conserved across species. We speculate that cleavage at the NH(2) terminus of Asp(197) of mouse DMP1 represents an initial, first-step scission in the whole cascade of proteolytic processing. To test if Asp(197) is critical for initiating the proteolytic processing of mouse DMP1, we substituted Asp(197) with Ala(197) by mutating the corresponding nucleotides of mouse cDNA that encode this amino acid residue. This mutant DMP1 cDNA was cloned into a pcDNA3.1 vector. Data from transfection experiments indicated that this single substitution blocked the proteolytic processing of mouse DMP1 in HEK-293 cells, indicating that cleavage at the NH(2) terminus of Asp(197) is essential for exposing other cleavage sites for the conversion of DMP1 to its fragments. The NH(2)-terminal fragment of DMP1 occurs as a proteoglycan form (DMP1-PG) that contains a glycosaminoglycan (GAG) chain. Previously, we showed that a GAG chain is linked to Ser(74) in rat DMP1 (Ser(89) in mouse DMP1). To confirm that mouse DMP1-PG possesses a single GAG chain attached to Ser(89), we substituted Ser(89) by Gly(89). Data from transfection analysis indicated that this substitution completely prevented formation of the GAG-containing form, confirming that DMP1-PG contains a single GAG chain attached to Ser(89) in mouse DMP1. Copyright 2008 S. Karger AG, Basel.

The Smn-Independent Beneficial Effects of Trichostatin A on an Intermediate Mouse Model of Spinal Muscular Atrophy

PubMed Central

Murray, Lyndsay M.; Beauvais, Ariane; Kothary, Rashmi

2014-01-01

Spinal muscular atrophy is an autosomal recessive neuromuscular disease characterized by the progressive loss of alpha motor neurons in the spinal cord. Trichostatin A (TSA) is a histone deacetylase inhibitor with beneficial effects in spinal muscular atrophy mouse models that carry the human SMN2 transgene. It is currently unclear whether TSA specifically targets the SMN2 gene or whether other genes respond to TSA and in turn provide neuroprotection in SMA mice. We have taken advantage of the Smn2B/- mouse model that does not harbor the human SMN2 transgene, to test the hypothesis that TSA has its beneficial effects through a non-SMN mediated pathway. TSA increased the median lifespan of Smn2B/- mice from twenty days to eight weeks. As well, there was a significant attenuation of weight loss and improved motor behavior. Pen test and righting reflex both showed significant improvement, and motor neurons in the spinal cord of Smn2B/- mice were protected from degeneration. Both the size and maturity of neuromuscular junctions were significantly improved in TSA treated Smn2B/- mice. Of interest, TSA treatment did not increase the levels of Smn protein in mouse embryonic fibroblasts or myoblasts obtained from the Smn2B/- mice. In addition, no change in the level of Smn transcripts or protein in the brain or spinal cord of TSA-treated SMA model mice was observed. Furthermore, TSA did not increase Smn protein levels in the hind limb muscle, heart, or liver of Smn2B/- mice. We therefore conclude that TSA likely exerts its effects independent of the endogenous mouse Smn gene. As such, identification of the pathways regulated by TSA in the Smn2B/- mice could lead to the development of novel therapeutics for treating SMA. PMID:24984019

A novel instrumented multipeg running wheel system, Step-Wheel, for monitoring and controlling complex sequential stepping in mice

PubMed Central

Nagata, Masatoshi; Yanagihara, Dai; Tomioka, Ryohei; Utsumi, Hideko; Kubota, Yasuo; Yagi, Takeshi; Graybiel, Ann M.; Yamamori, Tetsuo

2011-01-01

Motor control is critical in daily life as well as in artistic and athletic performance and thus is the subject of intense interest in neuroscience. Mouse models of movement disorders have proven valuable for many aspects of investigation, but adequate methods for analyzing complex motor control in mouse models have not been fully established. Here, we report the development of a novel running-wheel system that can be used to evoke simple and complex stepping patterns in mice. The stepping patterns are controlled by spatially organized pegs, which serve as footholds that can be arranged in adjustable, ladder-like configurations. The mice run as they drink water from a spout, providing reward, while the wheel turns at a constant speed. The stepping patterns of the mice can thus be controlled not only spatially, but also temporally. A voltage sensor to detect paw touches is attached to each peg, allowing precise registration of footfalls. We show that this device can be used to analyze patterns of complex motor coordination in mice. We further demonstrate that it is possible to measure patterns of neural activity with chronically implanted tetrodes as the mice engage in vigorous running bouts. We suggest that this instrumented multipeg running wheel (which we name the Step-Wheel System) can serve as an important tool in analyzing motor control and motor learning in mice. PMID:21525375

A novel instrumented multipeg running wheel system, Step-Wheel, for monitoring and controlling complex sequential stepping in mice.

PubMed

Kitsukawa, Takashi; Nagata, Masatoshi; Yanagihara, Dai; Tomioka, Ryohei; Utsumi, Hideko; Kubota, Yasuo; Yagi, Takeshi; Graybiel, Ann M; Yamamori, Tetsuo

2011-07-01

Motor control is critical in daily life as well as in artistic and athletic performance and thus is the subject of intense interest in neuroscience. Mouse models of movement disorders have proven valuable for many aspects of investigation, but adequate methods for analyzing complex motor control in mouse models have not been fully established. Here, we report the development of a novel running-wheel system that can be used to evoke simple and complex stepping patterns in mice. The stepping patterns are controlled by spatially organized pegs, which serve as footholds that can be arranged in adjustable, ladder-like configurations. The mice run as they drink water from a spout, providing reward, while the wheel turns at a constant speed. The stepping patterns of the mice can thus be controlled not only spatially, but also temporally. A voltage sensor to detect paw touches is attached to each peg, allowing precise registration of footfalls. We show that this device can be used to analyze patterns of complex motor coordination in mice. We further demonstrate that it is possible to measure patterns of neural activity with chronically implanted tetrodes as the mice engage in vigorous running bouts. We suggest that this instrumented multipeg running wheel (which we name the Step-Wheel System) can serve as an important tool in analyzing motor control and motor learning in mice.

Age dependent regulation of bone-mass and renal function by the MEPE ASARM-motif

PubMed Central

Zelenchuk, Lesya V; Hedge, Anne-Marie; Rowe, Peter S N

2015-01-01

Context Mice with null mutations in Matrix Extracellular Phosphoglycoprotein (MEPE) have increased bone mass, increased trabecular density and abnormal cancellous bone (MN-mice). These defects worsen with age and MEPE over expression induces opposite effects. Also, Genome Wide Association studies show MEPE plays a major role in bone mass. We hypothesized the conserved C-terminal MEPE ASARM-motif is chiefly responsible for regulating bone mass and trabecular structure. Design To test our theory we over expressed C-terminal ASARM-peptide in MN-mice using the Col1α1 promoter (MNAt-mice). We then compared the bone and renal phenotypes of the MNAt-mouse with the MN-mouse and the X-linked hypophosphatemic rickets mouse (HYP). The HYP mouse over expresses ASARM-peptides and is defective for the PHEX gene. Results The MN-mouse developed increased bone mass, bone strength and trabecular abnormalities that worsened markedly with age. Defects in bone formation were chiefly responsible with suppressed sclerostin and increased active β-catenin. Increased uric acid levels also suggested abnormalities in purine-metabolism and a reduced fractional excretion of uric acid signaled additional renal transport changes. The MN mouse developed a worsening hyperphosphatemia and reduced FGF23 with age. An increase in the fractional excretion of phosphate (FEP) despite the hyperphosphatemia confirms an imbalance in kidney-intestinal phosphate regulation. Also, the MN mice showed an increased creatinine clearance suggesting hyperfiltration. A reversal of the MN bone-renal phenotype changes occurred with the MNAt mice including the apparent hyperfiltration. The MNAt mice also developed localized hypomineralization, hypophosphatemia and increased FGF23. Conclusions The C-terminal ASARM-motif plays a major role in regulating bone–mass and cancellous structure as mice age. In healthy mice, the processing and release of free ASARM-peptide is chiefly responsible for preserving normal bone and renal function. Free ASARM-peptide also effects renal mineral phosphate handling by influencing FGF23 expression. These findings have implications for understanding age-dependent osteoporosis, unraveling drug-targets and developing treatments. PMID:26051469

The HIV-1 viral protein Tat increases glutamate and decreases GABA exocytosis from human and mouse neocortical nerve endings.

PubMed

Musante, Veronica; Summa, Maria; Neri, Elisa; Puliti, Aldamaria; Godowicz, Tomasz T; Severi, Paolo; Battaglia, Giuseppe; Raiteri, Maurizio; Pittaluga, Anna

2010-08-01

Human immunodeficiency virus-1 (HIV-1)-encoded transactivator of transcription (Tat) potentiated the depolarization-evoked exocytosis of [(3)H]D-aspartate ([(3)H]D-ASP) from human neocortical terminals. The metabotropic glutamate (mGlu) 1 receptor antagonist 7-(hydroxyimino)cyclopropa[b]chromen-1a-carboxylate ethyl ester (CPCCOEt) prevented this effect, whereas the mGlu5 receptor antagonist 2-methyl-6-(phenylethynyl) pyridine hydrochloride (MPEP) was ineffective. Western blot analysis showed that human neocortex synaptosomes possess mGlu1 and mGlu5 receptors. Tat potentiated the K(+)-evoked release of [(3)H]D-ASP or of endogenous glutamate from mouse neocortical synaptosomes in a CPCCOEt-sensitive and MPEP-insensitive manner. Deletion of mGlu1 receptors (crv4/crv4 mice) or mGlu5 receptors (mGlu5(-/-)mouse) silenced Tat effects. Tat enhanced inositol 1,4,5-trisphosphate production in human and mouse neocortical synaptosomes, consistent with the involvement of group I mGlu receptors. Tat inhibited the K(+)-evoked release of [(3)H]gamma-aminobutyric acid ([(3)H]GABA) from human synaptosomes and that of endogenous GABA or [(3)H]GABA from mouse nerve terminals; the inhibition was insensitive to CPCCOEt or MPEP. Tat-induced effects were retained by Tat(37-72) but not by Tat(48-85). In mouse neocortical slices, Tat facilitated the K(+)- and the veratridine-induced release of [(3)H]D-ASP in a CPCCOEt-sensitive manner and was ineffective in crv4/crv4 mouse slices. These observations are relevant to the comprehension of the pathophysiological effects of Tat in central nervous system and may suggest new potential therapeutic approaches to the cure of HIV-1-associated dementia.

The serotonergic system in Parkinson's patients with dyskinesia: evidence from imaging studies.

PubMed

Pagano, Gennaro; Niccolini, Flavia; Politis, Marios

2017-12-20

The purpose of review is to review the current status of positron emission tomography (PET) molecular imaging of serotonergic system in Parkinson's patients who experience levodopa-induced (LIDs) and graft-induced dyskinesias (GIDs). PET imaging studies have shown that Parkinson's disease is characterized by progressive loss of dopaminergic and serotonergic neurons. Parkinson's patients who experienced LIDs and GIDs have an aberrant spreading of serotonergic terminals, which lead to an increased serotonergic/dopaminergic terminals ratio within the putamen. Serotonergic terminals convert exogenous levodopa into dopamine in a non-physiological manner and release an abnormal amount of dopamine without an auto-regulatory feedback. This results in higher swings in synaptic levels of dopamine, which leads to the development of LIDs and GIDs. The modulation of serotonergic terminals with 5-HT 1A and 5-HT 1B receptors agonists partially reduced these motor complications. In vivo PET studies confirmed that abnormal spreading of serotonergic terminals within the putamen has a pivotal role in the development of LIDs and GIDs. However, glutamatergic, adenosinergic, opioid systems, and phosphodiesterases 10A may also play a role in the development of these motor complications. An integrative multimodal imaging approach combining PET and MRI imaging techniques is needed to fully understand the mechanisms underlying the development of LIDs and GIDs.

Induction of motor neuron differentiation by transduction of Olig2 protein.

PubMed

Mie, Masayasu; Kaneko, Mami; Henmi, Fumiaki; Kobatake, Eiry

2012-10-26

Olig2 protein, a member of the basic helix-loop-helix transcription factor family, was introduced into the mouse embryonic carcinoma cell line P19 for induction of motor neuron differentiation. We show that Olig2 protein has the ability to permeate the cell membrane without the addition of a protein transduction domain (PTD), similar to other basic helix-loop-helix transcription factors such as MyoD and NeuroD2. Motor neuron differentiation was evaluated for the elongation of neurites and the expression of choline acetyltransferase (ChAT) mRNA, a differentiation marker of motor neurons. By addition of Olig2 protein, motor neuron differentiation was induced in P19 cells. Copyright © 2012 Elsevier Inc. All rights reserved.

40 CFR 86.1336-84 - Engine starting, restarting, and shutdown.

Code of Federal Regulations, 2010 CFR

2010-07-01

... dynamometer shall be equal (nominal ±0.5 seconds) to the time required with a starter motor. Motoring by the dynamometer shall be terminated not more than one second after the engine starts. The 24 ±1-second free idle... after 15 seconds of cranking, cranking shall cease and the reason for failure to start shall be...

40 CFR 80.583 - What alternative sampling and testing requirements apply to importers who transport motor vehicle...

Code of Federal Regulations, 2010 CFR

2010-07-01

... applicable. (b) Quality assurance program. The importer must conduct a quality assurance program, as specified in this paragraph (b), for each truck or rail car loading terminal. (1) Quality assurance samples... an independent laboratory, and the terminal operator must not know in advance when samples are to be...

Functional Analysis of Dopaminergic Systems in a DYT1 Knock-in Mouse Model of Dystonia

PubMed Central

Song, Chang-Hyun; Fan, Xueliang; Exeter, Cicely J.; Hess, Ellen J.; Jinnah, H. A.

2012-01-01

The dystonias are a group of disorders characterized by involuntary twisting movements and abnormal posturing. The most common of the inherited dystonias is DYT1 dystonia, which is due to deletion of a single GAG codon (ΔE) in the TOR1A gene that encodes torsinA. Since some forms of dystonia have been linked with dysfunction of brain dopamine pathways, the integrity of these pathways was explored in a knock-in mouse model of DYT1 dystonia. In DYT1(ΔE) knock-in mice, neurochemical measures revealed only small changes in the content of dopamine or its metabolites in tissue homogenates from caudoputamen or midbrain, but microdialysis studies revealed robust decreases in baseline and amphetamine-stimulated extracellular dopamine in the caudoputamen. Quantitative stereological methods revealed no evidence for striatal or midbrain atrophy, but substantia nigra neurons immunopositive for tyrosine hydroxylase were slightly reduced in numbers and enlarged in size. Behavioral studies revealed subtle abnormalities in gross motor activity and motor coordination without overt dystonia. Neuropharmacological challenges of dopamine systems revealed normal behavioral responses to amphetamine and a minor increase in sensitivity to haloperidol. These results demonstrate that this DYT1(ΔE) knock-in mouse model of dystonia harbors neurochemical and structural changes of the dopamine pathways, as well as motor abnormalities. PMID:22659308

Light microscopic detection of sugar residues in glycoconjugates of salivary glands and the pancreas with lectin-horseradish peroxidase conjugates. I. Mouse.

PubMed

Schulte, B A; Spicer, S S

1983-12-01

Mouse salivary glands and pancreases were stained with a battery of ten horseradish peroxidase-conjugated lectins. Lectin staining revealed striking differences in the structure of oligosaccharides of stored intracellular secretory glycoproteins and glycoconjugates associated with the surface of epithelial cells lining excretory ducts. The percentage of acinar cells containing terminal alpha-N-acetylgalactosamine residues varied greatly in submandibular glands of 30 male mice, but all submandibular acinar cells contained oligosaccharides with terminal sialic acid and penultimate beta-galactose residues. The last named dimer was abundant in secretory glycoprotein of all mucous acinar cells in murine sublingual glands and an additional 20-50% of these cells in all glands contained terminal N-acetylglucosamine residues. In contrast, terminal alpha-N-acetylgalactosamine was abundant in sublingual serous demilune secretions. Serous acinar cells in the exorbital lacrimal gland, posterior lingual gland, parotid gland and pancreas exhibited a staining pattern unique to each organ. In contrast, the apical cytoplasm and surface of striated duct epithelial cells in the submandibular, sublingual, parotid and exorbital lacrimal gland stained similarly. A comparison of staining with conjugated lectins reported biochemically to have very similar carbohydrate binding specificity has revealed some remarkable differences in their reactivity, suggesting different binding specificity for the same terminal sugars having different glycosidic linkages or with different penultimate sugar residues.

The Processed Amino-Terminal Fragment of Human TLR7 Acts as a Chaperone To Direct Human TLR7 into Endosomes

PubMed Central

Shepherd, Dawn; Booth, Sarah; Waithe, Dominic; Reis e Sousa, Caetano

2015-01-01

TLR7 mediates innate immune responses to viral RNA in endocytic compartments. Mouse and human (h)TLR7 undergo proteolytic cleavage, resulting in the generation of a C-terminal fragment that accumulates in endosomes and associates with the signaling adaptor MyD88 upon receptor triggering by TLR7 agonists. Although mouse TLR7 is cleaved in endosomes by acidic proteases, hTLR7 processing can occur at neutral pH throughout the secretory pathway through the activity of furin-like proprotein convertases. However, the mechanisms by which cleaved hTLR7 reaches the endosomal compartment remain unclear. In this study, we demonstrate that, after hTLR7 proteolytic processing, the liberated amino (N)-terminal fragment remains bound to the C terminus through disulfide bonds and provides key trafficking information that ensures correct delivery of the complex to endosomal compartments. In the absence of the N-terminal fragment, the C-terminal fragment is redirected to the cell surface, where it is functionally inactive. Our data reveal a novel role for the N terminus of hTLR7 as a molecular chaperone that provides processed hTLR7 with the correct targeting instructions to reach the endosomal compartment, hence ensuring its biological activity and preventing inadvertent cell surface responses to self-RNA. PMID:25917086

Structure, function and tissue forms of the C-terminal globular domain of collagen XVIII containing the angiogenesis inhibitor endostatin.

PubMed Central

Sasaki, T; Fukai, N; Mann, K; Göhring, W; Olsen, B R; Timpl, R

1998-01-01

The C-terminal domain NC1 of mouse collagen XVIII (38 kDa) and the shorter mouse and human endostatins (22 kDa) were prepared in recombinant form from transfected mammalian cells. The NC1 domain aggregated non-covalently into a globular trimer which was partially cleaved by endogenous proteolysis into several monomers (25-32 kDa) related to endostatin. Endostatins were obtained in a highly soluble, monomeric form and showed a single N-terminal sequence which, together with other data, indicated a compact folding. Endostatins and NC1 showed a comparable binding activity for the microfibrillar fibulin-1 and fibulin-2, and for heparin. Domain NC1, however, was a distinctly stronger ligand than endostatin for sulfatides and the basement membrane proteins laminin-1 and perlecan. Immunological assays demonstrated endostatin epitopes on several tissue components (22-38 kDa) and in serum (120-300 ng/ml), the latter representing the smaller variants. The data indicated that the NC1 domain consists of an N-terminal association region (approximately 50 residues), a central protease-sensitive hinge region (approximately 70 residues) and a C-terminal stable endostatin domain (approximately 180 residues). They also demonstrated that proteolytic release of endostatin can occur through several pathways, which may lead to a switch from a matrix-associated to a more soluble endocrine form. PMID:9687493

Insights from zebrafish and mouse models on the activity and safety of ar-turmerone as a potential drug candidate for the treatment of epilepsy.

PubMed

Orellana-Paucar, Adriana Monserrath; Afrikanova, Tatiana; Thomas, Joice; Aibuldinov, Yelaman K; Dehaen, Wim; de Witte, Peter A M; Esguerra, Camila V

2013-01-01

In a previous study, we uncovered the anticonvulsant properties of turmeric oil and its sesquiterpenoids (ar-turmerone, α-, β-turmerone and α-atlantone) in both zebrafish and mouse models of chemically-induced seizures using pentylenetetrazole (PTZ). In this follow-up study, we aimed at evaluating the anticonvulsant activity of ar-turmerone further. A more in-depth anticonvulsant evaluation of ar-turmerone was therefore carried out in the i.v. PTZ and 6-Hz mouse models. The potential toxic effects of ar-turmerone were evaluated using the beam walking test to assess mouse motor function and balance. In addition, determination of the concentration-time profile of ar-turmerone was carried out for a more extended evaluation of its bioavailability in the mouse brain. Ar-turmerone displayed anticonvulsant properties in both acute seizure models in mice and modulated the expression patterns of two seizure-related genes (c-fos and brain-derived neurotrophic factor [bdnf]) in zebrafish. Importantly, no effects on motor function and balance were observed in mice after treatment with ar-turmerone even after administering a dose 500-fold higher than the effective dose in the 6-Hz model. In addition, quantification of its concentration in mouse brains revealed rapid absorption after i.p. administration, capacity to cross the BBB and long-term brain residence. Hence, our results provide additional information on the anticonvulsant properties of ar-turmerone and support further evaluation towards elucidating its mechanism of action, bioavailability, toxicity and potential clinical application.

Insights from Zebrafish and Mouse Models on the Activity and Safety of Ar-Turmerone as a Potential Drug Candidate for the Treatment of Epilepsy

PubMed Central

Orellana-Paucar, Adriana Monserrath; Afrikanova, Tatiana; Thomas, Joice; Aibuldinov, Yelaman K.; Dehaen, Wim; de Witte, Peter A. M.; Esguerra, Camila V.

2013-01-01

In a previous study, we uncovered the anticonvulsant properties of turmeric oil and its sesquiterpenoids (ar-turmerone, α-, β-turmerone and α-atlantone) in both zebrafish and mouse models of chemically-induced seizures using pentylenetetrazole (PTZ). In this follow-up study, we aimed at evaluating the anticonvulsant activity of ar-turmerone further. A more in-depth anticonvulsant evaluation of ar-turmerone was therefore carried out in the i.v. PTZ and 6-Hz mouse models. The potential toxic effects of ar-turmerone were evaluated using the beam walking test to assess mouse motor function and balance. In addition, determination of the concentration-time profile of ar-turmerone was carried out for a more extended evaluation of its bioavailability in the mouse brain. Ar-turmerone displayed anticonvulsant properties in both acute seizure models in mice and modulated the expression patterns of two seizure-related genes (c-fos and brain-derived neurotrophic factor [bdnf]) in zebrafish. Importantly, no effects on motor function and balance were observed in mice after treatment with ar-turmerone even after administering a dose 500-fold higher than the effective dose in the 6-Hz model. In addition, quantification of its concentration in mouse brains revealed rapid absorption after i.p. administration, capacity to cross the BBB and long-term brain residence. Hence, our results provide additional information on the anticonvulsant properties of ar-turmerone and support further evaluation towards elucidating its mechanism of action, bioavailability, toxicity and potential clinical application. PMID:24349101

Protective B-cell epitopes of Francisella tularensis O-polysaccharide in a mouse model of respiratory tularaemia.

PubMed

Lu, Zhaohua; Madico, Guillermo; Roche, Marly I; Wang, Qi; Hui, Julia H; Perkins, Hillary M; Zaia, Joseph; Costello, Catherine E; Sharon, Jacqueline

2012-07-01

Antibodies to the lipopolysaccharide (LPS) of Francisella tularensis have been shown to be protective against respiratory tularaemia in mouse models, and we have previously described mouse monoclonal antibodies (mAbs) to non-overlapping terminal and internal epitopes of the F. tularensis LPS O-polysaccharide (OAg). In the current study, we used F. tularensis LPS oligosaccharides of defined OAg repeat length as molecular rulers in competition ELISA to demonstrate that the epitope targeted by the terminal OAg-binding mAb FB11 is contained within one tetrasaccharide repeat whereas the epitope targeted by the internal OAg-binding mAb Ab52 spans two tetrasaccharide repeats. Both mAbs conferred survival to BALB/c mice infected intranasally with the F. tularensis type B live vaccine strain and prolonged survival of BALB/c mice infected intranasally with the highly virulent F. tularensis type A strain SchuS4. The protective effects correlated with reduced bacterial burden in mAb-treated infected mice. These results indicate that an oligosaccharide with two OAg tetrasaccharide repeats covers both terminal and internal protective OAg epitopes, which may inform the design of vaccines for tularaemia. Furthermore, the FB11 and Ab52 mAbs could serve as reporters to monitor the response of vaccine recipients to protective B-cell epitopes of F. tularensis OAg. © 2012 The Authors. Immunology © 2012 Blackwell Publishing Ltd.

No consistent bioenergetic defects in presynaptic nerve terminals isolated from mouse models of Alzheimer’s disease

PubMed Central

Choi, Sung W.; Gerencser, Akos A.; Ng, Ryan; Flynn, James M.; Melov, Simon; Danielson, Steven R.; Gibson, Bradford W.; Nicholls, David G.; Bredesen, Dale E.; Brand, Martin D.

2012-01-01

Depressed cortical energy supply and impaired synaptic function are predominant associations of Alzheimer’s disease (AD). To test the hypothesis that presynaptic bioenergetic deficits are associated with the progression of AD pathogenesis, we compared bioenergetic variables of cortical and hippocampal presynaptic nerve terminals (synaptosomes) from commonly used mouse models with AD-like phenotypes (J20 age 6 months, Tg2576 age 16 months and APP/PS age 9 and 14 months) to age-matched controls. No consistent bioenergetic deficiencies were detected in synaptosomes from the three models, only APP/PS cortical synaptosomes from 14 month old mice showed an increase in respiration associated with proton leak. J20 mice were chosen for a highly stringent investigation of mitochondrial function and content. There were no significant differences in the quality of the synaptosomal preparations or the mitochondrial volume fraction. Furthermore, respiratory variables, calcium handling, and membrane potentials of synaptosomes from symptomatic J20 mice under calcium-imposed stress were not consistently impaired. The recovery of marker proteins during synaptosome preparation was the same, ruling out the possibility that the lack of functional bioenergetic defects in synaptosomes from J20 mice was due to the selective loss of damaged synaptosomes during sample preparation. Our results support the conclusion that the intrinsic bioenergetic capacities of presynaptic nerve terminals are maintained in these symptomatic AD mouse models. PMID:23175831

Motor Neuron Rescue in Spinal Muscular Atrophy Mice Demonstrates That Sensory-Motor Defects Are a Consequence, Not a Cause, of Motor Neuron Dysfunction

PubMed Central

Gogliotti, Rocky G.; Quinlan, Katharina A.; Barlow, Courtenay B.; Heier, Christopher R.; Heckman, C. J.

2012-01-01

The loss of motor neurons (MNs) is a hallmark of the neuromuscular disease spinal muscular atrophy (SMA); however, it is unclear whether this phenotype autonomously originates within the MN. To address this question, we developed an inducible mouse model of severe SMA that has perinatal lethality, decreased motor function, motor unit pathology, and hyperexcitable MNs. Using an Hb9-Cre allele, we increased Smn levels autonomously within MNs and demonstrate that MN rescue significantly improves all phenotypes and pathologies commonly described in SMA mice. MN rescue also corrects hyperexcitability in SMA motor neurons and prevents sensory-motor synaptic stripping. Survival in MN-rescued SMA mice is extended by only 5 d, due in part to failed autonomic innervation of the heart. Collectively, this work demonstrates that the SMA phenotype autonomously originates in MNs and that sensory-motor synapse loss is a consequence, not a cause, of MN dysfunction. PMID:22423102

Sumoylation of FOXP2 Regulates Motor Function and Vocal Communication Through Purkinje Cell Development.

PubMed

Usui, Noriyoshi; Co, Marissa; Harper, Matthew; Rieger, Michael A; Dougherty, Joseph D; Konopka, Genevieve

2017-02-01

Mutations in the gene encoding the transcription factor forkhead box P2 (FOXP2) result in brain developmental abnormalities, including reduced gray matter in both human patients and rodent models and speech and language deficits. However, neither the region-specific function of FOXP2 in the brain, in particular the cerebellum, nor the effects of any posttranslational modifications of FOXP2 in the brain and disorders have been explored. We characterized sumoylation of FOXP2 biochemically and analyzed the region-specific function and sumoylation of FOXP2 in the developing mouse cerebellum. Using in utero electroporation to manipulate the sumoylation state of FOXP2 as well as Foxp2 expression levels in Purkinje cells of the cerebellum in vivo, we reduced Foxp2 expression approximately 40% in the mouse cerebellum. Such a reduction approximates the haploinsufficiency observed in human patients who demonstrate speech and language impairments. We identified sumoylation of FOXP2 at K674 (K673 in mice) in the cerebellum of neonates. In vitro co-immunoprecipitation and in vivo colocalization experiments suggest that PIAS3 acts as the small ubiquitin-like modifier E3 ligase for FOXP2 sumoylation. This sumoylation modifies transcriptional regulation by FOXP2. We demonstrated that FOXP2 sumoylation is required for regulation of cerebellar motor function and vocal communication, likely through dendritic outgrowth and arborization of Purkinje cells in the mouse cerebellum. Sumoylation of FOXP2 in neonatal mouse cerebellum regulates Purkinje cell development and motor functions and vocal communication, demonstrating evidence for sumoylation in regulating mammalian behaviors. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Novel object exploration in the C58/J mouse model of autistic-like behavior.

PubMed

Blick, Mikkal G; Puchalski, Breann H; Bolanos, Veronica J; Wolfe, Kaitlin M; Green, Matthew C; Ryan, Bryce C

2015-04-01

Mouse models of autistic like behaviors are a valuable tool to use when studying the causes, symptoms, and potential treatments for autism. The inbred C58/J strain is a strain of interest for this model and has previously been shown to possess face validity for some of the core traits of autism, including low social behavior and elevated motor stereotypies. Higher order repetitive behaviors have not been extensively studied in this strain, or in mice in general. In this study, we looked for evidence of higher-order repetitive behaviors in the C58/J strain using a novel object assay. This assay utilized a mouse's natural exploratory behavior among unfamiliar objects to identify potential sequencing patterns in motor activity. The motor stereotypies displayed by the C58/J strain during testing were consistent with past studies. The C58/J strain also displayed a high preference for a single object in the round arena assays and the females demonstrating elevated sequencing patterns in the round arena. Although the C58/J strain did not show pervasive evidence of higher-order repetitive behaviors across all measures, there was evidence of higher order repetitive behaviors in certain situations. This study further demonstrates the potential of the C58/J mouse strains as a model for lower-order and potentially, higher-order repetitive behaviors. This study also demonstrates that the shape of the novel object arena can change the behavior displayed by the test animals. Further studies utilizing the C58/J strain and further validation of the novel object assay are warranted. Copyright © 2014 Elsevier B.V. All rights reserved.

Distinct projection targets define subpopulations of mouse brainstem vagal neurons that express the autism-associated MET receptor tyrosine kinase.

PubMed

Kamitakahara, Anna; Wu, Hsiao-Huei; Levitt, Pat

2017-12-15

Detailed anatomical tracing and mapping of the viscerotopic organization of the vagal motor nuclei has provided insight into autonomic function in health and disease. To further define specific cellular identities, we paired information based on visceral connectivity with a cell-type specific marker of a subpopulation of neurons in the dorsal motor nucleus of the vagus (DMV) and nucleus ambiguus (nAmb) that express the autism-associated MET receptor tyrosine kinase. As gastrointestinal disturbances are common in children with autism spectrum disorder (ASD), we sought to define the relationship between MET-expressing (MET+) neurons in the DMV and nAmb, and the gastrointestinal tract. Using wholemount tissue staining and clearing, or retrograde tracing in a MET EGFP transgenic mouse, we identify three novel subpopulations of EGFP+ vagal brainstem neurons: (a) EGFP+ neurons in the nAmb projecting to the esophagus or laryngeal muscles, (b) EGFP+ neurons in the medial DMV projecting to the stomach, and (b) EGFP+ neurons in the lateral DMV projecting to the cecum and/or proximal colon. Expression of the MET ligand, hepatocyte growth factor (HGF), by tissues innervated by vagal motor neurons during fetal development reveal potential sites of HGF-MET interaction. Furthermore, similar cellular expression patterns of MET in the brainstem of both the mouse and nonhuman primate suggests that MET expression at these sites is evolutionarily conserved. Together, the data suggest that MET+ neurons in the brainstem vagal motor nuclei are anatomically positioned to regulate distinct portions of the gastrointestinal tract, with implications for the pathophysiology of gastrointestinal comorbidities of ASD. © 2017 Wiley Periodicals, Inc.

Identification of age-dependent motor and neuropsychological behavioural abnormalities in a mouse model of Mucopolysaccharidosis Type II

PubMed Central

Gleitz, Hélène F. E.; O’Leary, Claire; Holley, Rebecca J.

2017-01-01

Severe mucopolysaccharidosis type II (MPS II) is a progressive lysosomal storage disease caused by mutations in the IDS gene, leading to a deficiency in the iduronate-2-sulfatase enzyme that is involved in heparan sulphate and dermatan sulphate catabolism. In constitutive form, MPS II is a multi-system disease characterised by progressive neurocognitive decline, severe skeletal abnormalities and hepatosplenomegaly. Although enzyme replacement therapy has been approved for treatment of peripheral organs, no therapy effectively treats the cognitive symptoms of the disease and novel therapies are in development to remediate this. Therapeutic efficacy and subsequent validation can be assessed using a variety of outcome measures that are translatable to clinical practice, such as behavioural measures. We sought to consolidate current knowledge of the cognitive, skeletal and motor abnormalities present in the MPS II mouse model by performing time course behavioural examinations of working memory, anxiety, activity levels, sociability and coordination and balance, up to 8 months of age. Cognitive decline associated with alterations in spatial working memory is detectable at 8 months of age in MPS II mice using spontaneous alternation, together with an altered response to novel environments and anxiolytic behaviour in the open-field. Coordination and balance on the accelerating rotarod were also significantly worse at 8 months, and may be associated with skeletal changes seen in MPS II mice. We demonstrate that the progressive nature of MPS II disease is also seen in the mouse model, and that cognitive and motor differences are detectable at 8 months of age using spontaneous alternation, the accelerating rotarod and the open-field tests. This study establishes neurological, motor and skeletal measures for use in pre-clinical studies to develop therapeutic approaches in MPS II. PMID:28207863

A Motor-Gradient and Clustering Model of the Centripetal Motility of MTOCs in Meiosis I of Mouse Oocytes

PubMed Central

2016-01-01

Asters nucleated by Microtubule (MT) organizing centers (MTOCs) converge on chromosomes during spindle assembly in mouse oocytes undergoing meiosis I. Time-lapse imaging suggests that this centripetal motion is driven by a biased ‘search-and-capture’ mechanism. Here, we develop a model of a random walk in a drift field to test the nature of the bias and the spatio-temporal dynamics of the search process. The model is used to optimize the spatial field of drift in simulations, by comparison to experimental motility statistics. In a second step, this optimized gradient is used to determine the location of immobilized dynein motors and MT polymerization parameters, since these are hypothesized to generate the gradient of forces needed to move MTOCs. We compare these scenarios to self-organized mechanisms by which asters have been hypothesized to find the cell-center- MT pushing at the cell-boundary and clustering motor complexes. By minimizing the error between simulation outputs and experiments, we find a model of “pulling” by a gradient of dynein motors alone can drive the centripetal motility. Interestingly, models of passive MT based “pushing” at the cortex, clustering by cross-linking motors and MT-dynamic instability gradients alone, by themselves do not result in the observed motility. The model predicts the sensitivity of the results to motor density and stall force, but not MTs per aster. A hybrid model combining a chromatin-centered immobilized dynein gradient, diffusible minus-end directed clustering motors and pushing at the cell cortex, is required to comprehensively explain the available data. The model makes experimentally testable predictions of a spatial bias and self-organized mechanisms by which MT asters can find the center of a large cell. PMID:27706163

Not GABA but glycine mediates segmental, propriospinal, and bulbospinal postsynaptic inhibition in adult mouse spinal forelimb motor neurons.

PubMed

Jiang, Juan; Alstermark, Bror

2015-02-04

The general view is that both glycine (Eccles, 1964) and GABA (Curtis and Felix, 1971) evoke postsynaptic inhibition in spinal motor neurons. In newborn or juvenile animals, there are conflicting results showing postsynaptic inhibition in motor neurons by corelease of GABA and glycine (Jonas et al., 1998) or by glycine alone (Bhumbra et al., 2012). To resolve the relative contributions of GABA and glycine to postsynaptic inhibition, we performed in vivo intracellular recordings from forelimb motor neurons in adult mice. Postsynaptic potentials evoked from segmental, propriospinal, and bulbospinal systems in motor neurons were compared across four different conditions: control, after gabazine, gabazine followed by strychnine, and strychnine alone. No significant differences were observed in the proportion of IPSPs and EPSPs between control and gabazine conditions. In contrast, EPSPs but not IPSPs were recorded after adding strychnine with gabazine or administering strychnine alone, suggesting an exclusive role for glycine in postsynaptic inhibition. To test whether the injected (intraperitoneal) dose of gabazine blocked GABAergic inhibitory transmission, we evoked GABAA receptor-mediated monosynaptic IPSPs in deep cerebellar nuclei neurons by stimulation of Purkinje cell fibers. No monosynaptic IPSPs could be recorded in the presence of gabazine, showing the efficacy of gabazine treatment. Our results demonstrate that, in the intact adult mouse, the postsynaptic inhibitory effects in spinal motor neurons exerted by three different systems, intrasegmental and intersegmental as well as supraspinal, are exclusively glycinergic. These findings emphasize the importance of glycinergic postsynaptic inhibition in motor neurons and challenge the view that GABA also contributes. Copyright © 2015 the authors 0270-6474/15/351991-08$15.00/0.

A Motor-Gradient and Clustering Model of the Centripetal Motility of MTOCs in Meiosis I of Mouse Oocytes.

PubMed

Khetan, Neha; Athale, Chaitanya A

2016-10-01

Asters nucleated by Microtubule (MT) organizing centers (MTOCs) converge on chromosomes during spindle assembly in mouse oocytes undergoing meiosis I. Time-lapse imaging suggests that this centripetal motion is driven by a biased 'search-and-capture' mechanism. Here, we develop a model of a random walk in a drift field to test the nature of the bias and the spatio-temporal dynamics of the search process. The model is used to optimize the spatial field of drift in simulations, by comparison to experimental motility statistics. In a second step, this optimized gradient is used to determine the location of immobilized dynein motors and MT polymerization parameters, since these are hypothesized to generate the gradient of forces needed to move MTOCs. We compare these scenarios to self-organized mechanisms by which asters have been hypothesized to find the cell-center- MT pushing at the cell-boundary and clustering motor complexes. By minimizing the error between simulation outputs and experiments, we find a model of "pulling" by a gradient of dynein motors alone can drive the centripetal motility. Interestingly, models of passive MT based "pushing" at the cortex, clustering by cross-linking motors and MT-dynamic instability gradients alone, by themselves do not result in the observed motility. The model predicts the sensitivity of the results to motor density and stall force, but not MTs per aster. A hybrid model combining a chromatin-centered immobilized dynein gradient, diffusible minus-end directed clustering motors and pushing at the cell cortex, is required to comprehensively explain the available data. The model makes experimentally testable predictions of a spatial bias and self-organized mechanisms by which MT asters can find the center of a large cell.

Sex matters: Systemic complement activity of female C57BL/6J and BALB/cJ mice is limited by serum terminal pathway components.

PubMed

Kotimaa, Juha; Klar-Mohammad, Ngaisah; Gueler, Faikah; Schilders, Geurt; Jansen, Aswin; Rutjes, Helma; Daha, Mohamed R; van Kooten, Cees

2016-08-01

Experimental mouse models have been extensively used to elucidate the role of the complement system in different diseases and injuries. Contribution of gender has revealed an intriguing gender specific difference; female mice often show protection against most complement driven injuries such as ischemia/reperfusion injury, graft rejection and sepsis. Interestingly, early studies to the mouse complement system revealed that female mice have very low total complement activity (CH50), which is related to androgen regulation of hepatic complement synthesis. Here, our aim was to understand at which level the female specific differences in mouse complement resides. We have used recently developed complement assays to study the functional activities of female and male mice at the level of C3 and C9 activation, and furthermore assayed key complement factor levels in serum of age-matched female and male C57BL/6 mice. Our results show that the female mice have normal complement cascade functionality at the level of C3 activation, which was supported by determinations of early complement factors. However, all pathways are strongly reduced at the level of C9 activation, suggesting a terminal pathway specific difference. This was in line with C6 and C9 measurements, showing strongly decreased levels in females. Furthermore, similar gender differences were also found in BALB/cJ mice, but not in CD-1 mice. Our results clearly demonstrate that the complement system in females of frequently used mouse strains is restricted by the terminal pathway components and that the perceived female specific protection against experimental disease and injury might be in part explained by the inability promote inflammation through C5b-9. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Organization of projections from the spinal trigeminal subnucleus oralis to the spinal cord in the rat: a neuroanatomical substrate for reciprocal orofacial-cervical interactions.

PubMed

Devoize, Laurent; Doméjean, Sophie; Melin, Céline; Raboisson, Patrick; Artola, Alain; Dallel, Radhouane

2010-07-09

The organization of efferent projections from the spinal trigeminal nucleus oralis (Sp5O) to the spinal cord in the rat was studied using the anterograde tracer Phaseolus vulgaris leucoagglutinin. Sp5O projections to the spinal cord are restricted to the cervical cord. No labeled terminal can be detected in the thoracic and lumbar cord. The organization of these projections happens to critically depend on the dorso-ventral location of the injection site. On the one hand, the dorsal part of the Sp5O projects to the medial part of the dorsal horn (laminae III-V) at the C1 level, on the ipsilateral side, and to the ventral horn, on both sides but mainly on the ipsilateral one. Ipsilateral labeled terminals are distributed throughout laminae VII to IX but tend to cluster around the dorso-medial motor nuclei, especially at C3-C5 levels. Within the contralateral ventral horn, label terminals are found particularly in the region of the ventro-medial motor nucleus. This projection extends as far caudally as C3 or C4 level. On the other hand, the ventral part of the Sp5O projects to the lateral part of the dorsal horn (laminae III-V) at the C1 level, on the ipsilateral side, and to the ventral horn, on both sides but mainly on the contralateral one. Contralateral labeled terminals are distributed within the region of the dorso- and ventro-medial motor nuclei at C1-C4 levels whereas they are restricted to the dorso-medial motor nucleus at C5-C8 levels. These findings suggest that Sp5O is involved in the coordination of neck movements and in the modulation of incoming sensory information at the cervical spinal cord. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Antibodies to Both Terminal and Internal B-Cell Epitopes of Francisella tularensis O-Polysaccharide Produced by Patients with Tularemia

PubMed Central

Lu, Zhaohua; Perkins, Hillary M.

2014-01-01

Francisella tularensis, the Gram-negative bacterium that causes tularemia, is considered a potential bioterrorism threat due to its low infectivity dose and the high morbidity and mortality from respiratory disease. We previously characterized two mouse monoclonal antibodies (MAbs) specific for the O-polysaccharide (O antigen [OAg]) of F. tularensis lipopolysaccharide (LPS): Ab63, which targets a terminal epitope at the nonreducing end of OAg, and Ab52, which targets a repeating internal OAg epitope. These two MAbs were protective in a mouse model of respiratory tularemia. To determine whether these epitope types are also targeted by humans, we tested the ability of each of 18 blood serum samples from 11 tularemia patients to inhibit the binding of Ab63 or Ab52 to F. tularensis LPS in a competition enzyme-linked immunosorbent assay (ELISA). Although all serum samples had Ab63- and Ab52-inhibitory activities, the ratios of Ab63 to Ab52 inhibitory potencies varied 75-fold. However, the variation was only 2.3-fold for sequential serum samples from the same patient, indicating different distributions of terminal- versus internal-binding antibodies in different individuals. Western blot analysis using class-specific anti-human Ig secondary antibodies showed that both terminal- and internal-binding OAg antibodies were of the IgG, IgM, and IgA isotypes. These results support the use of a mouse model to discover protective B-cell epitopes for tularemia vaccines or prophylactic/therapeutic antibodies, and they present a general strategy for interrogating the antibody responses of patients and vaccinees to microbial carbohydrate epitopes that have been characterized in experimental animals. PMID:24351753

Gain in Transcriptional Activity by Primate-specific Coevolution of Melanoma Antigen-A11 and Its Interaction Site in Androgen Receptor*

PubMed Central

Liu, Qiang; Su, Shifeng; Blackwelder, Amanda J.; Minges, John T.; Wilson, Elizabeth M.

2011-01-01

Male sex development and growth occur in response to high affinity androgen binding to the androgen receptor (AR). In contrast to complete amino acid sequence conservation in the AR DNA and ligand binding domains among mammals, a primate-specific difference in the AR NH2-terminal region that regulates the NH2- and carboxyl-terminal (N/C) interaction enables direct binding to melanoma antigen-A11 (MAGE-11), an AR coregulator that is also primate-specific. Human, mouse, and rat AR share the same NH2-terminal 23FQNLF27 sequence that mediates the androgen-dependent N/C interaction. However, the mouse and rat AR FXXLF motif is flanked by Ala33 that evolved to Val33 in primates. Human AR Val33 was required to interact directly with MAGE-11 and for the inhibitory effect of the AR N/C interaction on activation function 2 that was relieved by MAGE-11. The functional importance of MAGE-11 was indicated by decreased human AR regulation of an androgen-dependent endogenous gene using lentivirus short hairpin RNAs and by the greater transcriptional strength of human compared with mouse AR. MAGE-11 increased progesterone and glucocorticoid receptor activity independently of binding an FXXLF motif by interacting with p300 and p160 coactivators. We conclude that the coevolution of the AR NH2-terminal sequence and MAGE-11 expression among primates provides increased regulatory control over activation domain dominance. Primate-specific expression of MAGE-11 results in greater steroid receptor transcriptional activity through direct interactions with the human AR FXXLF motif region and indirectly through steroid receptor-associated p300 and p160 coactivators. PMID:21730049

Oligodendrocyte- and Neuron-Specific Nogo-A Restrict Dendritic Branching and Spine Density in the Adult Mouse Motor Cortex.

PubMed

Zemmar, Ajmal; Chen, Chia-Chien; Weinmann, Oliver; Kast, Brigitt; Vajda, Flora; Bozeman, James; Isaad, Noel; Zuo, Yi; Schwab, Martin E

2018-06-01

Nogo-A has been well described as a myelin-associated inhibitor of neurite outgrowth and functional neuroregeneration after central nervous system (CNS) injury. Recently, a new role of Nogo-A has been identified as a negative regulator of synaptic plasticity in the uninjured adult CNS. Nogo-A is present in neurons and oligodendrocytes. However, it is yet unclear which of these two pools regulate synaptic plasticity. To address this question we used newly generated mouse lines in which Nogo-A is specifically knocked out in (1) oligodendrocytes (oligoNogo-A KO) or (2) neurons (neuroNogo-A KO). We show that both oligodendrocyte- and neuron-specific Nogo-A KO mice have enhanced dendritic branching and spine densities in layer 2/3 cortical pyramidal neurons. These effects are compartmentalized: neuronal Nogo-A affects proximal dendrites whereas oligodendrocytic Nogo-A affects distal regions. Finally, we used two-photon laser scanning microscopy to measure the spine turnover rate of adult mouse motor cortex layer 5 cells and find that both Nogo-A KO mouse lines show enhanced spine remodeling after 4 days. Our results suggest relevant control functions of glial as well as neuronal Nogo-A for synaptic plasticity and open new possibilities for more selective and targeted plasticity enhancing strategies.

Celecoxib increases SMN and survival in a severe spinal muscular atrophy mouse model via p38 pathway activation.

PubMed

Farooq, Faraz; Abadía-Molina, Francisco; MacKenzie, Duncan; Hadwen, Jeremiah; Shamim, Fahad; O'Reilly, Sean; Holcik, Martin; MacKenzie, Alex

2013-09-01

The loss of functional Survival Motor Neuron (SMN) protein due to mutations or deletion in the SMN1 gene causes autosomal recessive neurodegenerative spinal muscle atrophy (SMA). A potential treatment strategy for SMA is to upregulate the amount of SMN protein originating from the highly homologous SMN2 gene, compensating in part for the absence of the functional SMN1 gene. We have previously shown that in vitro activation of the p38 pathway stabilizes and increases SMN mRNA levels leading to increased SMN protein levels. In this report, we explore the impact of the p38 activating, FDA-approved, blood brain barrier permeating compound celecoxib on SMN levels in vitro and in a mouse model of SMA. We demonstrate a significant induction of SMN protein levels in human and mouse neuronal cells upon treatment with celecoxib. We show that activation of the p38 pathway by low doses celecoxib increases SMN protein in a HuR protein-dependent manner. Furthermore, celecoxib treatment induces SMN expression in brain and spinal cord samples of wild-type mice in vivo. Critically, celecoxib treatment increased SMN levels, improved motor function and enhanced survival in a severe SMA mouse model. Our results identify low dose celecoxib as a potential new member of the SMA therapeutic armamentarium.

Effects of Antiepileptic Drugs on Spontaneous Recurrent Seizures in a Novel Model of Extended Hippocampal Kindling in Mice

PubMed Central

Song, Hongmei; Tufa, Uilki; Chow, Jonathan; Sivanenthiran, Nila; Cheng, Chloe; Lim, Stellar; Wu, Chiping; Feng, Jiachun; Eubanks, James H.; Zhang, Liang

2018-01-01

Epilepsy is a common neurological disorder characterized by naturally-occurring spontaneous recurrent seizures and comorbidities. Kindling has long been used to model epileptogenic mechanisms and to assess antiepileptic drugs. In particular, extended kindling can induce spontaneous recurrent seizures without gross brain lesions, as seen clinically. To date, the development of spontaneous recurrent seizures following extended kindling, and the effect of the antiepileptic drugs on these seizures are not well understood. In the present study we aim to develop a mouse model of extended hippocampal kindling for the first time. Once established, we plan to evaluate the effect of three different antiepileptic drugs on the development of the extended-hippocampal-kindled-induced spontaneous recurrent seizures. Male C57 black mice were used for chronic hippocampal stimulations or handling manipulations (twice daily for up to 70 days). Subsequently, animals underwent continuous video/EEG monitoring for seizure detection. Spontaneous recurrent seizures were consistently observed in extended kindled mice but no seizures were detected in the control animals. The aforementioned seizures were generalized events characterized by hippocampal ictal discharges and concurrent motor seizures. Incidence and severity of the seizures was relatively stable while monitored over a few months after termination of the hippocampal stimulation. Three antiepileptic drugs with distinct action mechanisms were tested: phenytoin, lorazepam and levetiracetam. They were applied via intra-peritoneal injections at anticonvulsive doses and their effects on the spontaneous recurrent seizures were analyzed 10–12 h post-injection. Phenytoin (25 mg/kg) and levetiracetam (400 mg/kg) abolished the spontaneous recurrent seizures. Lorazepam (1.5 mg/kg) decreased motor seizure severity but did not reduce the incidence and duration of corresponding hippocampal discharges, implicating its inhibitory effects on seizure spread. No gross brain lesions were observed in a set of extended hippocampal kindled mice submitted to histological evaluation. All these data suggests that our model could be considered as a novel mouse model of extended hippocampal kindling. Some limitations remain to be considered. PMID:29867462

The effects of two phospholipase A2 inhibitors on the neuromuscular blocking activities of homologous phospholipases A2 from the venom of Pseudechis australis, the Australian king brown snake.

PubMed

Fatehi, M; Rowan, E G; Harvey, A L

1995-12-01

Previous studies have shown that homologous phospholipases A2 (PLA2) (Pa-3, Pa-9C, Pa-10F and Pa-11) from the venom of the Australian king brown snake, Pseudechis australis, significantly reduce the resting membrane potentials and quantal contents of endplate potentials recorded from endplate regions of mouse triangularis sterni nerve-muscle preparations. It is not clear whether PLA2 activity is essential for their neuromuscular activities. Therefore, pharmacological studies were carried out to determine whether neuromuscular activity of the toxins changed after treatment with the phospholipase A2 inhibitors 7,7-dimethyl-eicosadienoic acid (DEDA) and manoalide. After incubation of the toxins with manoalide (120 nM), or DEDA (50 microM), no PLA2 activity against 1-stearoyl 2-[3H]arachidonoylglycerophosphocholine was detected. After incubation with manoalide and/or DEDA, the toxins did not depolarize muscle fibre membranes up to 60 min after administration. However, manoalide and DEDA had different influences on the inhibitory effect of these toxic enzymes on acetylcholine release from nerve terminals. Manoalide abolished the inhibitory effect of the toxins on evoked release of acetylcholine. In contrast, DEDA was not able to prevent the reduction of quantal content of endplate potentials induced by the toxins. This study provides evidence that the depolarizing action and the inhibitory effect on release of acetylcholine exerted by these toxic PLA2 from king brown snake are independent phenomena. The evidence for this conclusion was that inhibition of enzymatic activity with an arachidonic acid analogue (DEDA) abolished the depolarizing effect of the toxins but not the effects on the quantal release of acetylcholine from mouse motor nerve terminals. The data suggest that the depolarizing effect of these toxins is probably due to the enzymatic activity. Since manoalide interacts with lysine residues of PLA2 polypeptides, and, as shown here, manoalide prevented inhibition of neurotransmitter release, lysine residues may play an important role in the inhibitory activity of these toxins.

Evidence that the extraocular motor nuclei innervate monkey palisade endings.

PubMed

Zimmermann, Lars; May, Paul J; Pastor, Angel M; Streicher, Johannes; Blumer, Roland

2011-02-04

Palisade endings are found in the extraocular muscles (EOMs) of almost every mammalian species, including primates. These nerve specializations surrounding the muscle fiber insertion have been postulated to be the proprioceptors of the EOMs. However, it was recently demonstrated that palisade endings have a cholinergic nature, which reopened the question of whether palisade endings are motor or sensory structures. In this work, we examined whether the cell bodies of palisade endings lie in EOM motor nuclei by injecting an anterograde tracer, biotinylated dextran amine, into the abducens nucleus of a macaque monkey. Tracer visualization in the lateral rectus muscle was combined with choline acetyltransferase (ChAT) and α-bungarotoxin staining. Analysis of the samples was performed by conventional light microscopy and confocal laser scanning microscopy. About 30% of the nerve fibers innervating the muscle were tracer positive. These were ChAT positive as well. Tracer positive nerve fibers established motor contacts on singly and multiply innervated muscle fibers, which were confirmed by α-bungarotoxin staining. At the transition between muscle and distal tendon, we found palisade endings that contained tracer. Palisade endings exhibited the classic morphology: axons arising from the muscle extend onto the tendon, then turn back 180° and terminate in a cuff of terminals around an individual muscle fiber tip. This finding suggests that the cell bodies of palisade endings lie in the EOM motor nuclei, which complements prior studies demonstrating a cholinergic, and possibly motor, phenotype for palisade endings. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Evidence that the extraocular motor nuclei innervate monkey palisade endings

PubMed Central

Zimmermann, Lars; May, Paul J.; Pastor, Ángel M.; Streicher, Johannes; Blumer, Roland

2011-01-01

Palisade endings are found in the extraocular muscles (EOMs) of almost every mammalian species, including primates. These nerve specializations surrounding the muscle fiber insertion have been postulated to be the proprioceptors of the EOMs. However, it was recently demonstrated that palisade endings have a cholinergic nature, which reopened the question of whether palisade endings are motor or sensory structures. In this work, we examined whether the cell bodies of palisade endings lie in EOM motor nuclei by injecting an anterograde tracer, biotinylated dextran amine, into the abducens nucleus of a macaque monkey. Tracer visualization in the lateral rectus muscle was combined with choline acetyltransferase (ChAT) and α-bungarotoxin staining. Analysis of the samples was performed by conventional light microscopy and confocal laser scanning microscopy. About 30% of the nerve fibers innervating the muscle were tracer positive. These were ChAT positive as well. Tracer positive nerve fibers established motor contacts on singly and multiply innervated muscle fibers, which were confirmed by α-bungarotoxin staining. At the transition between muscle and distal tendon, we found palisade endings that contained tracer. Palisade endings exhibited the classic morphology: axons arising from the muscle extend onto the tendon, then turn back 180° and terminate in a cuff of terminals around an individual muscle fiber tip. This finding suggests that the cell bodies of palisade endings lie in the EOM motor nuclei, which complements prior studies demonstrating a cholinergic, and possibly motor, phenotype for palisade endings. PMID:21138754

49 CFR 1.73 - Delegation to the Administrator of the Federal Motor Carrier Safety Administration.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 14504a relating to Federal-State relations, and section 14506 relating to identification of vehicles; (8... Termination Act of 1995, Public Law 104-88, 109 Stat. 803, relating to miscellaneous motor carrier provisions... warranting denial of the license; and (2) Section 4123(c), (d) and (e) of Public Law 109-59, 119 Stat. 1735...

78 FR 49982 - Airworthiness Directives; Saab AB, Saab Aerosystems Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-16

...) Replacement Except as provided by paragraph (k) of this AD: Using the hour reading on the A/C compressor hour... accordance with paragraph (k)(1) of this AD until the conditions listed in paragraphs (j)(1)(i) through (j)(1... ducts to gain access to the drive motor. (4) Disconnect power leads from motor terminals (1/4-28). Tag...

Position and Speed Control of Brushless DC Motors Using Sensorless Techniques and Application Trends

PubMed Central

Gamazo-Real, José Carlos; Vázquez-Sánchez, Ernesto; Gómez-Gil, Jaime

2010-01-01

This paper provides a technical review of position and speed sensorless methods for controlling Brushless Direct Current (BLDC) motor drives, including the background analysis using sensors, limitations and advances. The performance and reliability of BLDC motor drivers have been improved because the conventional control and sensing techniques have been improved through sensorless technology. Then, in this paper sensorless advances are reviewed and recent developments in this area are introduced with their inherent advantages and drawbacks, including the analysis of practical implementation issues and applications. The study includes a deep overview of state-of-the-art back-EMF sensing methods, which includes Terminal Voltage Sensing, Third Harmonic Voltage Integration, Terminal Current Sensing, Back-EMF Integration and PWM strategies. Also, the most relevant techniques based on estimation and models are briefly analysed, such as Sliding-mode Observer, Extended Kalman Filter, Model Reference Adaptive System, Adaptive observers (Full-order and Pseudoreduced-order) and Artificial Neural Networks. PMID:22163582

Expansion and concatenation of nonmuscle myosin IIA filaments drive cellular contractile system formation during interphase and mitosis

PubMed Central

Fenix, Aidan M.; Taneja, Nilay; Buttler, Carmen A.; Lewis, John; Van Engelenburg, Schuyler B.; Ohi, Ryoma; Burnette, Dylan T.

2016-01-01

Cell movement and cytokinesis are facilitated by contractile forces generated by the molecular motor, nonmuscle myosin II (NMII). NMII molecules form a filament (NMII-F) through interactions of their C-terminal rod domains, positioning groups of N-terminal motor domains on opposite sides. The NMII motors then bind and pull actin filaments toward the NMII-F, thus driving contraction. Inside of crawling cells, NMIIA-Fs form large macromolecular ensembles (i.e., NMIIA-F stacks), but how this occurs is unknown. Here we show NMIIA-F stacks are formed through two non–mutually exclusive mechanisms: expansion and concatenation. During expansion, NMIIA molecules within the NMIIA-F spread out concurrent with addition of new NMIIA molecules. Concatenation occurs when multiple NMIIA-Fs/NMIIA-F stacks move together and align. We found that NMIIA-F stack formation was regulated by both motor activity and the availability of surrounding actin filaments. Furthermore, our data showed expansion and concatenation also formed the contractile ring in dividing cells. Thus interphase and mitotic cells share similar mechanisms for creating large contractile units, and these are likely to underlie how other myosin II–based contractile systems are assembled. PMID:26960797

Terminal changes in hereditary sensory and autonomic neuropathy: a long-term follow-up of a sporadic case.

PubMed

Lee, Sang-Soo; Lee, Sung-Hyun; Han, Seol-Heui

2003-07-01

We describe terminal changes in a long-term follow-up of a 51-year-old man with sporadic hereditary sensory and autonomic neuropathy (HSAN). From the age of 15 years onwards, he suffered from multiple painless ulcers of his feet and fingers, necessitating amputation. Neurological studies revealed almost complete sensory loss affecting all modalities in the upper and lower limbs, minimal involvement of motor fibers, and areflexia. A neurophysiological abnormality involved an absence of sensory action potentials with relatively normal motor nerve conduction velocities. Biopsy of the sural nerve showed almost total loss of myelinated fibers with a mild decrease in unmyelinated fibers. Despite the late onset of the disease, the progressive course, and the lancinating pain, the terminal features of this patient, which involved a selective loss of myelinated fibers and widespread sensory loss, seem to be symptomatic of HSAN II, the progressive form of autosomal recessive sensory neuropathy, and emphasize the clinical heterogeneity of HSAN.

Early white matter abnormalities, progressive brain pathology and motor deficits in a novel knock-in mouse model of Huntington's disease

PubMed Central

Jin, Jing; Peng, Qi; Hou, Zhipeng; Jiang, Mali; Wang, Xin; Langseth, Abraham J.; Tao, Michael; Barker, Peter B.; Mori, Susumu; Bergles, Dwight E.; Ross, Christopher A.; Detloff, Peter J.; Zhang, Jiangyang; Duan, Wenzhen

2015-01-01

White matter abnormalities have been reported in premanifest Huntington's disease (HD) subjects before overt striatal neuronal loss, but whether the white matter changes represent a necessary step towards further pathology and the underlying mechanism of these changes remains unknown. Here, we characterized a novel knock-in mouse model that expresses mouse HD gene homolog (Hdh) with extended CAG repeat- HdhQ250, which was derived from the selective breeding of HdhQ150 mice. HdhQ250 mice manifest an accelerated and robust phenotype compared with its parent line. HdhQ250 mice exhibit progressive motor deficits, reduction in striatal and cortical volume, accumulation of mutant huntingtin aggregation, decreased levels of DARPP32 and BDNF and altered striatal metabolites. The abnormalities detected in this mouse model are reminiscent of several aspects of human HD. In addition, disturbed myelination was evident in postnatal Day 14 HdhQ250 mouse brain, including reduced levels of myelin regulatory factor and myelin basic protein, and decreased numbers of myelinated axons in the corpus callosum. Thinner myelin sheaths, indicated by increased G-ratio of myelin, were also detected in the corpus callosum of adult HdhQ250 mice. Moreover, proliferation of oligodendrocyte precursor cells is altered by mutant huntingtin both in vitro and in vivo. Our data indicate that this model is suitable for understanding comprehensive pathogenesis of HD in white matter and gray matter as well as developing therapeutics for HD. PMID:25609071

Effects of the synthetic neurosteroid ganaxolone on seizure activity and behavioral deficits in an Angelman syndrome mouse model.

PubMed

Ciarlone, Stephanie L; Wang, Xinming; Rogawski, Michael A; Weeber, Edwin J

2017-04-01

Angelman syndrome (AS) is a rare neurogenetic disorder characterized by severe developmental delay, motor impairments, and epilepsy. GABAergic dysfunction is believed to contribute to many of the phenotypic deficits seen in AS. We hypothesized that restoration of inhibitory tone mediated by extrasynaptic GABA A receptors could provide therapeutic benefit. Here, we report that ganaxolone, a synthetic neurosteroid that acts as a positive allosteric modulator of synaptic and extrasynaptic GABA A receptors, was anxiolytic, anticonvulsant, and improved motor deficits in the Ube3a-deficient mouse model of AS when administered by implanted mini-pump for 3 days or 4 weeks. Treatment for 4 weeks also led to recovery of spatial working memory and hippocampal synaptic plasticity deficits. This study demonstrates that ganaxolone ameliorates many of the behavioral abnormalities in the adult AS mouse, and tolerance did not occur to the therapeutic effects of the drug. The results support clinical studies to investigate ganaxolone as a symptomatic treatment for AS. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quantifying Morphological Parameters of the Terminal Branching Units in a Mouse Lung by Phase Contrast Synchrotron Radiation Computed Tomography

PubMed Central

Hwang, Jeongeun; Kim, Miju; Kim, Seunghwan; Lee, Jinwon

2013-01-01

An effective technique of phase contrast synchrotron radiation computed tomography was established for the quantitative analysis of the microstructures in the respiratory zone of a mouse lung. Heitzman’s method was adopted for the whole-lung sample preparation, and Canny’s edge detector was used for locating the air-tissue boundaries. This technique revealed detailed morphology of the respiratory zone components, including terminal bronchioles and alveolar sacs, with sufficiently high resolution of 1.74 µm isotropic voxel size. The technique enabled visual inspection of the respiratory zone components and comprehension of their relative positions in three dimensions. To check the method’s feasibility for quantitative imaging, morphological parameters such as diameter, surface area and volume were measured and analyzed for sixteen randomly selected terminal branching units, each consisting of a terminal bronchiole and a pair of succeeding alveolar sacs. The four types of asymmetry ratios concerning alveolar sac mouth diameter, alveolar sac surface area, and alveolar sac volume are measured. This is the first ever finding of the asymmetry ratio for the terminal bronchioles and alveolar sacs, and it is noteworthy that an appreciable degree of branching asymmetry was observed among the alveolar sacs at the terminal end of the airway tree, despite the number of samples was small yet. The series of efficient techniques developed and confirmed in this study, from sample preparation to quantification, is expected to contribute to a wider and exacter application of phase contrast synchrotron radiation computed tomography to a variety of studies. PMID:23704918

Prejunctional and postjunctional actions of heptanol and 18 beta-glycyrretinic acid in the rodent vas deferens.

PubMed

Rahman, Faisal; Manchanda, Rohit; Brain, Keith L

2009-06-15

Heptanol and 18 beta-glycyrrhetinic acid (18 beta GA) block gap junctions, but have other actions on transmitter release that have not been characterised. This study investigates the prejunctional and postjunctional effects of these compounds in guinea pig and mouse vas deferens using intracellular electrophysiological recording and confocal Ca(2+) imaging of sympathetic nerve terminals. In mice, heptanol (2 mM) reversibly decreased the amplitude of purinergic excitatory junction potentials (EJPs; 52+/-5%, P<0.05) while having little effect on spontaneous excitatory junction potentials (sEJPs). Heptanol (2 mM) reversibly abolished the nerve terminal Ca(2+) transient in 52% of terminals. 18 beta GA (10 microM) decreased the mean EJP amplitude, and increased input resistance in both mouse (137+/-17%, P<0.05) and guinea pig (354+/-50%, P<0.001) vas deferens indicating gap junction blockade. Further, 18 beta GA increased the sEJP frequency significantly in guinea pigs (by 71+/-25%, P<0.05) and in 5 out of 6 tissues in mice (19+/-3%, P<0.05). Moreover, 18 beta GA depolarised cells from both mice (11+/-1%, P<0.01) and guinea pigs (8+/-1%, P<0.005). Therefore, we conclude that heptanol (2 mM) decreases neurotransmitter release (given the decrease in EJP amplitude) by abolishing the nerve terminal action potential in a proportion of nerve terminals. 18 betaGA (10 microM) effectively blocks the gap junctions, but the increase in sEJP frequency suggests an additional prejunctional effect, which might involve the induction of spontaneous nerve terminal action potentials.

An anticholinergic reverses motor control and corticostriatal LTD deficits in Dyt1 ΔGAG knock-in mice

PubMed Central

Dang, Mai T.; Yokoi, Fumiaki; Cheetham, Chad C.; Lu, Jun; Vo, Viet; Lovinger, David M.; Li, Yuqing

2011-01-01

DYT1 early-onset generalized torsion dystonia is an inherited movement disorder associated with mutations in DYT1 that codes for torsinA protein. The most common mutation seen in this gene is a trinucleotide deletion of GAG. We previously reported a motor control deficit on a beam-walking task in our Dyt1 ΔGAG knock-in heterozygous mice. In this report we show the reversal of this motor deficit with the anticholinergic trihexyphenidyl (THP), a drug commonly used to treat movement problems in dystonia patients. THP also restored the reduced corticostriatal long-term depression (LTD) observed in these mice. Corticostriatal LTD has long been known to be dependent on D2 receptor activation. In this mouse model, striatal D2 receptors were expressed at lower quantities in comparison to wild-type mice. Furthermore, the mice were also partially resistant to FPL64176, an agonist of L-type calcium channels that have been previously reported to cause severe dystonic-like symptoms in wild-type mice. Our findings collectively suggest that altered communication between cholinergic interneurons and medium spiny neurons is responsible for the LTD deficit and that this synaptic plasticity modification may be involved in the striatal motor control abnormalities in our mouse model of DYT1 dystonia. PMID:21995941

Resveratrol Ameliorates Motor Neuron Degeneration and Improves Survival in SOD1G93A Mouse Model of Amyotrophic Lateral Sclerosis

PubMed Central

Song, Lin; Zhang, Xiaojie; Li, Jia; Le, Weidong

2014-01-01

Resveratrol has recently been used as a supplemental treatment for several neurological and nonneurological diseases. It is not known whether resveratrol has neuroprotective effect on amyotrophic lateral sclerosis (ALS). To assess the effect of resveratrol on the disease, we tested this agent on an ALS model of SOD1G93A transgenic mouse. Rotarod measurement was performed to measure the motor function of the ALS mice. Nissl staining and SMI-32 immunofluorescent staining were used to determine motor neurons survival in the spinal cord of the ALS mice. Hematoxylin-eosin (H&E), succinic dehydrogenase (SDH), and cytochrome oxidase (COX) staining were applied to pathologically analyze the skeletal muscles of the ALS mice. We found that resveratrol treatment significantly delayed the disease onset and prolonged the lifespan of the ALS mice. Furthermore, resveratrol treatment attenuated motor neuron loss, relieved muscle atrophy, and improved mitochondrial function of muscle fibers in the ALS mice. In addition, we demonstrated that resveratrol exerted these neuroprotective effects mainly through increasing the expression of Sirt1, consequently suppressing oxidative stress and downregulating p53 and its related apoptotic pathway. Collectively, our findings suggest that resveratrol might provide a promising therapeutic intervention for ALS. PMID:25057490

Mice deficient in carbonic anhydrase type 8 exhibit motor dysfunctions and abnormal calcium dynamics in the somatic region of cerebellar granule cells.

PubMed

Lamont, Matthew G; Weber, John T

2015-06-01

The waddles (wdl) mouse is characterized by a namesake "side-to-side" waddling gait due to a homozygous mutation of the Car8 gene. This mutation results in non-functional copies of the protein carbonic anhydrase type 8. Rota-rod testing was conducted to characterize the wdl mutations' effect on motor output. Results indicated that younger homozygotes outperformed their older cohorts, an effect not seen in previous studies. Heterozygotes, which were thought to be free of motor impairment, displayed motor learning deficiencies when compared with wild type performance. Acute cerebellar slices were then utilized for fluorescent calcium imaging experiments, which revealed significant alterations in cerebellar granule cell somatic calcium signaling when exposed to glutamate. The contribution of GABAergic signaling to these alterations was also verified using bath application of bicuculline. Changes in somatic calcium signals were found to be applicable to an in vivo scenario by comparing group responses to electrical stimulation of afferent mossy fiber projections. Finally, intracellular calcium store function was also found to be altered by the wdl mutation when slices were treated with thapsigargin. These findings, taken together with previous work on the wdl mouse, indicate a widespread disruption in cerebellar circuitry hampering proper neuronal communication. Copyright © 2015 Elsevier B.V. All rights reserved.

J Genes for Heavy Chain Immunoglobulins of Mouse

NASA Astrophysics Data System (ADS)

Newell, Nanette; Richards, Julia E.; Tucker, Philip W.; Blattner, Frederick R.

1980-09-01

A 15.8-kilobase pair fragment of BALB/c mouse liver DNA, cloned in the Charon 4Aλ phage vector system, was shown to contain the μ heavy chain constant region (CHμ ) gene for the mouse immunoglobulin M. In addition, this fragment of DNA contains at least two J genes, used to code for the carboxyl terminal portion of heavy chain variable regions. These genes are located in genomic DNA about eight kilobase pairs to the 5' side of the CHμ gene. The complete nucleotide sequence of a 1120-base pair stretch of DNA that includes the two J genes has been determined.

Equipment & New Products.

ERIC Educational Resources Information Center

Poitras, Adrian W., Ed.

1979-01-01

Reviews new science equipment and products for the laboratory. Includes hand-held calculators, fiberglass fume hoods, motorized microtomy, disposable mouse cages, and electric timers. Describes 11 products total. Provides manufacturer name, address, and price. (MA)

Human sperm bind to the N-terminal domain of ZP2 in humanized zonae pellucidae in transgenic mice

PubMed Central

Baibakov, Boris; Boggs, Nathan A.; Yauger, Belinda; Baibakov, Galina

2012-01-01

Fertilization requires taxon-specific gamete recognition, and human sperm do not bind to zonae pellucidae (ZP1–3) surrounding mouse eggs. Using transgenesis to replace endogenous mouse proteins with human homologues, gain-of-function sperm-binding assays were established to evaluate human gamete recognition. Human sperm bound only to zonae pellucidae containing human ZP2, either alone or coexpressed with other human zona proteins. Binding to the humanized matrix was a dominant effect that resulted in human sperm penetration of the zona pellucida and accumulation in the perivitelline space, where they were unable to fuse with mouse eggs. Using recombinant peptides, the site of gamete recognition was located to a defined domain in the N terminus of ZP2. These results provide experimental evidence for the role of ZP2 in mediating sperm binding to the zona pellucida and support a model in which human sperm–egg recognition is dependent on an N-terminal domain of ZP2, which is degraded after fertilization to provide a definitive block to polyspermy. PMID:22734000

The retrograde delivery of adenovirus vector carrying the gene for brain-derived neurotrophic factor protects neurons and oligodendrocytes from apoptosis in the chronically compressed spinal cord of twy/twy mice.

PubMed

Uchida, Kenzo; Nakajima, Hideaki; Hirai, Takayuki; Yayama, Takafumi; Chen, Kebing; Guerrero, Alexander Rodriguez; Johnson, William Eustace; Baba, Hisatoshi

2012-12-15

The twy/twy mouse undergoes spontaneous chronic mechanical compression of the spinal cord; this in vivo model system was used to examine the effects of retrograde adenovirus (adenoviral vector [AdV])-mediated brain-derived neurotrophic factor (BDNF) gene delivery to spinal neural cells. To investigate the targeting and potential neuroprotective effect of retrograde AdV-mediated BDNF gene transfection in the chronically compressed spinal cord in terms of prevention of apoptosis of neurons and oligodendrocytes. Several studies have investigated the neuroprotective effects of neurotrophins, including BDNF, in spinal cord injury. However, no report has described the effects of retrograde neurotrophic factor gene delivery in compressed spinal cords, including gene targeting and the potential to prevent neural cell apoptosis. AdV-BDNF or AdV-LacZ (as a control gene) was injected into the bilateral sternomastoid muscles of 18-week old twy/twy mice for retrograde gene delivery via the spinal accessory motor neurons. Heterozygous Institute of Cancer Research mice (+/twy), which do not undergo spontaneous spinal compression, were used as a control for the effects of such compression on gene delivery. The localization and cell specificity of β-galactosidase expression (produced by LacZ gene transfection) and BDNF expression in the spinal cord were examined by coimmunofluorescence staining for neural cell markers (NeuN, neurons; reactive immunology protein, oligodendrocytes; glial fibrillary acidic protein, astrocytes; OX-42, microglia) 4 weeks after gene injection. The possible neuroprotection afforded by retrograde AdV-BDNF gene delivery versus AdV-LacZ-transfected control mice was assessed by scoring the prevalence of apoptotic cells (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling-positive cells) and immunoreactivity to active caspases -3, -8, and -9, p75, neurofilament 200 kD (NF), and for the oligodendroglial progenitor marker, NG2. RESULTS.: Four weeks after injection, the retrograde delivery of the LacZ marker gene was identified in cervical spinal neurons and some glial cells, including oligodendrocytes in the white matter of the spinal cord, in both the twy/twy mouse and the heterozygous Institute of Cancer Research mouse (+/twy). In the compressed spinal cord of twy/twy mouse, AdV-BDNF gene transfection resulted in a significant decrease in the number of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling-positive cells present in the spinal cord and a downregulation in the caspase apoptotic pathway compared with AdV-LacZ (control) gene transfection. There was a marked and significant increase in the areas of the spinal cord of AdV-BDNF-injected mice that were NF- and NG2-immunopositive compared with AdV-LacZ-injected mice, indicating the increased presence of neurons and oligodendrocytes in response to BDNF transfection. Our results demonstrate that targeted retrograde BDNF gene delivery suppresses apoptosis in neurons and oligodendrocytes in the chronically compressed spinal cord of twy/twy mouse. Further work is required to establish whether this method of gene delivery may provide neuroprotective effects in other situations of compressive spinal cord injury.

Gamma motor neurons survive and exacerbate alpha motor neuron degeneration in ALS.

PubMed

Lalancette-Hebert, Melanie; Sharma, Aarti; Lyashchenko, Alexander K; Shneider, Neil A

2016-12-20

The molecular and cellular basis of selective motor neuron (MN) vulnerability in amyotrophic lateral sclerosis (ALS) is not known. In genetically distinct mouse models of familial ALS expressing mutant superoxide dismutase-1 (SOD1), TAR DNA-binding protein 43 (TDP-43), and fused in sarcoma (FUS), we demonstrate selective degeneration of alpha MNs (α-MNs) and complete sparing of gamma MNs (γ-MNs), which selectively innervate muscle spindles. Resistant γ-MNs are distinct from vulnerable α-MNs in that they lack synaptic contacts from primary afferent (I A ) fibers. Elimination of these synapses protects α-MNs in the SOD1 mutant, implicating this excitatory input in MN degeneration. Moreover, reduced I A activation by targeted reduction of γ-MNs in SOD1 G93A mutants delays symptom onset and prolongs lifespan, demonstrating a pathogenic role of surviving γ-MNs in ALS. This study establishes the resistance of γ-MNs as a general feature of ALS mouse models and demonstrates that synaptic excitation of MNs within a complex circuit is an important determinant of relative vulnerability in ALS.

Gamma motor neurons survive and exacerbate alpha motor neuron degeneration in ALS

PubMed Central

Lalancette-Hebert, Melanie; Sharma, Aarti; Lyashchenko, Alexander K.; Shneider, Neil A.

2016-01-01

The molecular and cellular basis of selective motor neuron (MN) vulnerability in amyotrophic lateral sclerosis (ALS) is not known. In genetically distinct mouse models of familial ALS expressing mutant superoxide dismutase-1 (SOD1), TAR DNA-binding protein 43 (TDP-43), and fused in sarcoma (FUS), we demonstrate selective degeneration of alpha MNs (α-MNs) and complete sparing of gamma MNs (γ-MNs), which selectively innervate muscle spindles. Resistant γ-MNs are distinct from vulnerable α-MNs in that they lack synaptic contacts from primary afferent (IA) fibers. Elimination of these synapses protects α-MNs in the SOD1 mutant, implicating this excitatory input in MN degeneration. Moreover, reduced IA activation by targeted reduction of γ-MNs in SOD1G93A mutants delays symptom onset and prolongs lifespan, demonstrating a pathogenic role of surviving γ-MNs in ALS. This study establishes the resistance of γ-MNs as a general feature of ALS mouse models and demonstrates that synaptic excitation of MNs within a complex circuit is an important determinant of relative vulnerability in ALS. PMID:27930290

A mouse model of DEPDC5-related epilepsy: Neuronal loss of Depdc5 causes dysplastic and ectopic neurons, increased mTOR signaling, and seizure susceptibility.

PubMed

Yuskaitis, Christopher J; Jones, Brandon M; Wolfson, Rachel L; Super, Chloe E; Dhamne, Sameer C; Rotenberg, Alexander; Sabatini, David M; Sahin, Mustafa; Poduri, Annapurna

2018-03-01

DEPDC5 is a newly identified epilepsy-related gene implicated in focal epilepsy, brain malformations, and Sudden Unexplained Death in Epilepsy (SUDEP). In vitro, DEPDC5 negatively regulates amino acid sensing by the mTOR complex 1 (mTORC1) pathway, but the role of DEPDC5 in neurodevelopment and epilepsy has not been described. No animal model of DEPDC5-related epilepsy has recapitulated the neurological phenotypes seen in patients, and germline knockout rodent models are embryonic lethal. Here, we establish a neuron-specific Depdc5 conditional knockout mouse by cre-recombination under the Synapsin1 promotor. Depdc5 flox/flox -Syn1 Cre (Depdc5cc+) mice survive to adulthood with a progressive neurologic phenotype that includes motor abnormalities (i.e., hind limb clasping) and reduced survival compared to littermate control mice. Depdc5cc+ mice have larger brains with increased cortical neuron size and dysplastic neurons throughout the cortex, comparable to the abnormal neurons seen in human focal cortical dysplasia specimens. Depdc5 results in constitutive mTORC1 hyperactivation exclusively in neurons as measured by the increased phosphorylation of the downstream ribosomal protein S6. Despite a lack of increased mTORC1 signaling within astrocytes, Depdc5cc+ brains show reactive astrogliosis. We observed two Depdc5cc+ mice to have spontaneous seizures, including a terminal seizure. We demonstrate that as a group Depdc5cc+ mice have lowered seizure thresholds, as evidenced by decreased latency to seizures after chemoconvulsant injection and increased mortality from pentylenetetrazole-induced seizures. In summary, our neuron-specific Depdc5 knockout mouse model recapitulates clinical, pathological, and biochemical features of human DEPDC5-related epilepsy and brain malformations. We thereby present an important model in which to study targeted therapeutic strategies for DEPDC5-related conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

The effect of the DcpS inhibitor D156844 on the protective action of follistatin in mice with spinal muscular atrophy

PubMed Central

Harris, Ashlee W.; Butchbach, Matthew E. R.

2015-01-01

Spinal muscular atrophy (SMA), a leading genetic cause of pediatric death in the world, is an early-onset disease affecting the motor neurons in the anterior horn of the spinal cord. This degeneration of motor neurons leads to loss of muscle function. At the molecular level, SMA results from the loss of or mutation in the survival motor neuron 1 (SMN1) gene. The number of copies of the nearly duplicated gene SMN2 modulates the disease severity in humans as well as in transgenic mouse models for SMA. Most preclinical therapeutics trials focus on identifying ways to increase SMN2 expression and to alter its splicing. Other therapeutic strategies have investigated compounds which protect affected motor neurons and their target muscles in a SMN-independent manner. In the present study, the effect of a combination regimen of the SMN2 inducer D156844 and the protectant follistatin on the disease progression and survival was measured in the SMNΔ7 SMA mouse model. The D156844/follistatin combination treatment improved the survival of, delayed the endstage of disease in and ameliorated the growth rate of SMNΔ7 SMA mice better than follistatin treatment alone. The D156844/follistatin combination treatment, however, did not provide additional benefit over D156844 alone with respect to survival and disease endstage even though it provided some additional therapeutic benefit over D156844 alone with respect to motor phenotype. PMID:26055638

Differentiated NSC-34 cells as an in vitro Cell Model for VX

DTIC Science & Technology

2014-09-11

potential candidate drugs/antidotes. The development of an in vitro cellular model to aid in discovering new NA therapeutics would be highly beneficial...principally as potent cholinesterase inhibitors. The toxicity of these compounds and their mode of action are attributed to the inhibition of the enzyme ...of motor neuron- enriched, embryonic mouse spinal cord cells with mouse neuroblastoma as a potential neuronal model (Durham et al., 1993). This cell

Network properties of interstitial cells of Cajal affect intestinal pacemaker activity and motor patterns, according to a mathematical model of weakly coupled oscillators.

PubMed

Wei, Ruihan; Parsons, Sean P; Huizinga, Jan D

2017-03-01

What is the central question of this study? What are the effects of interstitial cells of Cajal (ICC) network perturbations on intestinal pacemaker activity and motor patterns? What is the main finding and its importance? Two-dimensional modelling of the ICC pacemaker activity according to a phase model of weakly coupled oscillators showed that network properties (coupling strength between oscillators, frequency gradient and frequency noise) strongly influence pacemaker network activity and subsequent motor patterns. The model explains motor patterns observed in physiological conditions and provides predictions and testable hypotheses for effects of ICC loss and frequency modulation on the motor patterns. Interstitial cells of Cajal (ICC) are the pacemaker cells of gut motility and are associated with motility disorders. Interstitial cells of Cajal form a network, but the contributions of its network properties to gut physiology and dysfunction are poorly understood. We modelled an ICC network as a two-dimensional network of weakly coupled oscillators with a frequency gradient and showed changes over time in video and graphical formats. Model parameters were obtained from slow-wave-driven contraction patterns in the mouse intestine and pacemaker slow-wave activities from the cat intestine. Marked changes in propagating oscillation patterns (including changes from propagation to non-propagating) were observed by changing network parameters (coupling strength between oscillators, the frequency gradient and frequency noise), which affected synchronization, propagation velocity and occurrence of dislocations (termination of an oscillation). Complete uncoupling of a circumferential ring of oscillators caused the proximal and distal section to desynchronize, but complete synchronization was maintained with only a single oscillator connecting the sections with high enough coupling. The network of oscillators could withstand loss; even with 40% of oscillators lost randomly within the network, significant synchronization and anterograde propagation remained. A local increase in pacemaker frequency diminished anterograde propagation; the effects were strongly dependent on location, frequency gradient and coupling strength. In summary, the model puts forth the hypothesis that fundamental changes in oscillation patterns (ICC slow-wave activity or circular muscle contractions) can occur through physiological modulation of network properties. Strong evidence is provided to accept the ICC network as a system of coupled oscillators. © 2016 The Authors. Experimental Physiology © 2016 The Physiological Society.

Expression of Sex Steroid Hormone Receptors in Vagal Motor Neurons Innervating the Trachea and Esophagus in Mouse

PubMed Central

Mukudai, Shigeyuki; Ichi Matsuda, Ken; Bando, Hideki; Takanami, Keiko; Nishio, Takeshi; Sugiyama, Yoichiro; Hisa, Yasuo; Kawata, Mitsuhiro

2016-01-01

The medullary vagal motor nuclei, the nucleus ambiguus (NA) and dorsal motor nucleus of the vagus (DMV), innervate the respiratory and gastrointestinal tracts. We conducted immunohistochemical analysis of expression of the androgen receptor (AR) and estrogen receptor α (ERα), in relation to innervation of the trachea and esophagus via vagal motor nuclei in mice. AR and ERα were expressed in the rostral NA and in part of the DMV. Tracing experiments using cholera toxin B subunit demonstrated that neurons of vagal motor nuclei that innervate the trachea and esophagus express AR and ERα. There was no difference in expression of sex steroid hormone receptors between trachea- and esophagus-innervating neurons. These results suggest that sex steroid hormones may act on vagal motor nuclei via their receptors, thereby regulating functions of the trachea and esophagus. PMID:27006520

Differential effects of myostatin deficiency on motor and sensory axons.

PubMed

Jones, Maria R; Villalón, Eric; Northcutt, Adam J; Calcutt, Nigel A; Garcia, Michael L

2017-12-01

Deletion of myostatin in mice (MSTN -/- ) alters structural properties of peripheral axons. However, properties like axon diameter and myelin thickness were analyzed in mixed nerves, so it is unclear whether loss of myostatin affects motor, sensory, or both types of axons. Using the MSTN -/- mouse model, we analyzed the effects of increasing the number of muscle fibers on axon diameter, myelin thickness, and internode length in motor and sensory axons. Axon diameter and myelin thickness were increased in motor axons of MSTN -/- mice without affecting internode length or axon number. The number of sensory axons was increased without affecting their structural properties. These results suggest that motor and sensory axons establish structural properties by independent mechanisms. Moreover, in motor axons, instructive cues from the neuromuscular junction may play a role in co-regulating axon diameter and myelin thickness, whereas internode length is established independently. Muscle Nerve 56: E100-E107, 2017. © 2017 Wiley Periodicals, Inc.

Touchscreen learning deficits in Ube3a, Ts65Dn and Mecp2 mouse models of neurodevelopmental disorders with intellectual disabilities.

PubMed

Leach, P T; Crawley, J N

2017-12-20

Mutant mouse models of neurodevelopmental disorders with intellectual disabilities provide useful translational research tools, especially in cases where robust cognitive deficits are reproducibly detected. However, motor, sensory and/or health issues consequent to the mutation may introduce artifacts that preclude testing in some standard cognitive assays. Touchscreen learning and memory tasks in small operant chambers have the potential to circumvent these confounds. Here we use touchscreen visual discrimination learning to evaluate performance in the maternally derived Ube3a mouse model of Angelman syndrome, the Ts65Dn trisomy mouse model of Down syndrome, and the Mecp2 Bird mouse model of Rett syndrome. Significant deficits in acquisition of a 2-choice visual discrimination task were detected in both Ube3a and Ts65Dn mice. Procedural control measures showed no genotype differences during pretraining phases or during acquisition. Mecp2 males did not survive long enough for touchscreen training, consistent with previous reports. Most Mecp2 females failed on pretraining criteria. Significant impairments on Morris water maze spatial learning were detected in both Ube3a and Ts65Dn, replicating previous findings. Abnormalities on rotarod in Ube3a, and on open field in Ts65Dn, replicating previous findings, may have contributed to the observed acquisition deficits and swim speed abnormalities during water maze performance. In contrast, these motor phenotypes do not appear to have affected touchscreen procedural abilities during pretraining or visual discrimination training. Our findings of slower touchscreen learning in 2 mouse models of neurodevelopmental disorders with intellectual disabilities indicate that operant tasks offer promising outcome measures for the preclinical discovery of effective pharmacological therapeutics. © 2017 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Evidence for an electrostatic mechanism of force generation by the bacteriophage T4 DNA packaging motor.

PubMed

Migliori, Amy D; Keller, Nicholas; Alam, Tanfis I; Mahalingam, Marthandan; Rao, Venigalla B; Arya, Gaurav; Smith, Douglas E

2014-06-17

How viral packaging motors generate enormous forces to translocate DNA into viral capsids remains unknown. Recent structural studies of the bacteriophage T4 packaging motor have led to a proposed mechanism wherein the gp17 motor protein translocates DNA by transitioning between extended and compact states, orchestrated by electrostatic interactions between complimentarily charged residues across the interface between the N- and C-terminal subdomains. Here we show that site-directed alterations in these residues cause force dependent impairments of motor function including lower translocation velocity, lower stall force and higher frequency of pauses and slips. We further show that the measured impairments correlate with computed changes in free-energy differences between the two states. These findings support the proposed structural mechanism and further suggest an energy landscape model of motor activity that couples the free-energy profile of motor conformational states with that of the ATP hydrolysis cycle.

Evidence for an electrostatic mechanism of force generation by the bacteriophage T4 DNA packaging motor

NASA Astrophysics Data System (ADS)

Migliori, Amy D.; Keller, Nicholas; Alam, Tanfis I.; Mahalingam, Marthandan; Rao, Venigalla B.; Arya, Gaurav; Smith, Douglas E.

2014-06-01

How viral packaging motors generate enormous forces to translocate DNA into viral capsids remains unknown. Recent structural studies of the bacteriophage T4 packaging motor have led to a proposed mechanism wherein the gp17 motor protein translocates DNA by transitioning between extended and compact states, orchestrated by electrostatic interactions between complimentarily charged residues across the interface between the N- and C-terminal subdomains. Here we show that site-directed alterations in these residues cause force dependent impairments of motor function including lower translocation velocity, lower stall force and higher frequency of pauses and slips. We further show that the measured impairments correlate with computed changes in free-energy differences between the two states. These findings support the proposed structural mechanism and further suggest an energy landscape model of motor activity that couples the free-energy profile of motor conformational states with that of the ATP hydrolysis cycle.

Evidence for an electrostatic mechanism of force generation by the bacteriophage T4 DNA packaging motor

PubMed Central

Migliori, Amy D.; Keller, Nicholas; Alam, Tanfis I.; Mahalingam, Marthandan; Rao, Venigalla B.; Arya, Gaurav; Smith, Douglas E

2014-01-01

How viral packaging motors generate enormous forces to translocate DNA into viral capsids remains unknown. Recent structural studies of the bacteriophage T4 packaging motor have led to a proposed mechanism wherein the gp17 motor protein translocates DNA by transitioning between extended and compact states, orchestrated by electrostatic interactions between complimentarily charged residues across the interface between the N- and C-terminal subdomains. Here, we show that site-directed alterations in these residues cause force dependent impairments of motor function including lower translocation velocity, lower stall force, and higher frequency of pauses and slips. We further show that the measured impairments correlate with computed changes in free energy differences between the two states. These findings support the proposed structural mechanism and further suggest an energy landscape model of motor activity that couples the free energy profile of motor conformational states with that of the ATP hydrolysis cycle. PMID:24937091

Crypto-rhombomeres of the mouse medulla oblongata, defined by molecular and morphological features.

PubMed

Tomás-Roca, Laura; Corral-San-Miguel, Rubén; Aroca, Pilar; Puelles, Luis; Marín, Faustino

2016-03-01

The medulla oblongata is the caudal portion of the vertebrate hindbrain. It contains major ascending and descending fiber tracts as well as several motor and interneuron populations, including neural centers that regulate the visceral functions and the maintenance of bodily homeostasis. In the avian embryo, it has been proposed that the primordium of this region is subdivided into five segments or crypto-rhombomeres (r7-r11), which were defined according to either their parameric position relative to intersomitic boundaries (Cambronero and Puelles, in J Comp Neurol 427:522-545, 2000) or a stepped expression of Hox genes (Marín et al., in Dev Biol 323:230-247, 2008). In the present work, we examine the implied similar segmental organization of the mouse medulla oblongata. To this end, we analyze the expression pattern of Hox genes from groups 3 to 8, comparing them to the expression of given cytoarchitectonic and molecular markers, from mid-gestational to perinatal stages. As a result of this approach, we conclude that the mouse medulla oblongata is segmentally organized, similarly as in avian embryos. Longitudinal structures such as the nucleus of the solitary tract, the dorsal vagal motor nucleus, the hypoglossal motor nucleus, the descending trigeminal and vestibular columns, or the reticular formation appear subdivided into discrete segmental units. Additionally, our analysis identified an internal molecular organization of the migrated pontine nuclei that reflects a differential segmental origin of their neurons as assessed by Hox gene expression.

Neuron-specific antioxidant OXR1 extends survival of a mouse model of amyotrophic lateral sclerosis.

PubMed

Liu, Kevin X; Edwards, Benjamin; Lee, Sheena; Finelli, Mattéa J; Davies, Ben; Davies, Kay E; Oliver, Peter L

2015-05-01

Amyotrophic lateral sclerosis is a devastating neurodegenerative disorder characterized by the progressive loss of spinal motor neurons. While the aetiological mechanisms underlying the disease remain poorly understood, oxidative stress is a central component of amyotrophic lateral sclerosis and contributes to motor neuron injury. Recently, oxidation resistance 1 (OXR1) has emerged as a critical regulator of neuronal survival in response to oxidative stress, and is upregulated in the spinal cord of patients with amyotrophic lateral sclerosis. Here, we tested the hypothesis that OXR1 is a key neuroprotective factor during amyotrophic lateral sclerosis pathogenesis by crossing a new transgenic mouse line that overexpresses OXR1 in neurons with the SOD1(G93A) mouse model of amyotrophic lateral sclerosis. Interestingly, we report that overexpression of OXR1 significantly extends survival, improves motor deficits, and delays pathology in the spinal cord and in muscles of SOD1(G93A) mice. Furthermore, we find that overexpression of OXR1 in neurons significantly delays non-cell-autonomous neuroinflammatory response, classic complement system activation, and STAT3 activation through transcriptomic analysis of spinal cords of SOD1(G93A) mice. Taken together, these data identify OXR1 as the first neuron-specific antioxidant modulator of pathogenesis and disease progression in SOD1-mediated amyotrophic lateral sclerosis, and suggest that OXR1 may serve as a novel target for future therapeutic strategies. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain.

Gait bradykinesia in Parkinson's disease: a change in the motor program which controls the synergy of gait.

PubMed

Warabi, Tateo; Furuyama, Hiroyasu; Sugai, Eri; Kato, Masamichi; Yanagisawa, Nobuo

2018-01-01

This study examined how gait bradykinesia is changed by the motor programming in Parkinson's disease. Thirty-five idiopathic Parkinson's disease patients and nine age-matched healthy subjects participated in this study. After the patients fixated on a visual-fixation target (conditioning-stimulus), the voluntary-gait was triggered by a visual on-stimulus. While the subject walked on a level floor, soleus, tibialis anterior EMG latencies, and the y-axis-vector of the sole-floor reaction force were examined. Three paradigms were used to distinguish between the off-/on-latencies. The gap-task: the visual-fixation target was turned off; 200 ms before the on-stimulus was engaged (resulting in a 200 ms-gap). EMG latency was not influenced by the visual-fixation target. The overlap-task: the on-stimulus was turned on during the visual-fixation target presentation (200 ms-overlap). The no-gap-task: the fixation target was turned off and the on-stimulus was turned on simultaneously. The onset of EMG pause following the tonic soleus EMG was defined as the off-latency of posture (termination). The onset of the tibialis anterior EMG burst was defined as the on-latency of gait (initiation). In the gap-task, the on-latency was unchanged in all of the subjects. In Parkinson's disease, the visual-fixation target prolonged both the off-/on-latencies in the overlap-task. In all tasks, the off-latency was prolonged and the off-/on-latencies were unsynchronized, which changed the synergic movement to a slow, short-step-gait. The synergy of gait was regulated by two independent sensory-motor programs of the off- and on-latency levels. In Parkinson's disease, the delayed gait initiation was due to the difficulty in terminating the sensory-motor program which controls the subject's fixation. The dynamic gait bradykinesia was involved in the difficulty (long off-latency) in terminating the motor program of the prior posture/movement.

Cloning, Characterization, and Expression Analysis of the Novel Acetyltransferase Retrogene Ard1b in the Mouse1

PubMed Central

Pang, Alan Lap-Yin; Peacock, Stephanie; Johnson, Warren; Bear, Deborah H.; Rennert, Owen M.; Chan, Wai-Yee

2009-01-01

N-alpha-terminal acetylation is a modification process that occurs cotranslationally on most eukaryotic proteins. The major enzyme responsible for this process, N-alpha-terminal acetyltransferase, is composed of the catalytic subunit ARD1A and the auxiliary subunit NAT1. We cloned, characterized, and studied the expression pattern of Ard1b (also known as Ard2), a novel homolog of the mouse Ard1a. Comparison of the genomic structures suggests that the autosomal Ard1b is a retroposed copy of the X-linked Ard1a. Expression analyses demonstrated a testis predominance of Ard1b. A reciprocal expression pattern between Ard1a and Ard1b is also observed during spermatogenesis, suggesting that Ard1b is expressed to compensate for the loss of Ard1a starting from meiosis. Both ARD1A and ARD1B can interact with NAT1 to constitute a functional N-alpha-terminal acetyltransferase in vitro. The expression of ARD1B protein can be detected in mouse testes but is delayed until the first appearance of round spermatids. In a cell culture model, the inclusion of the long 3′ untranslated region of Ard1b leads to reduction of luciferase reporter activity, which implicates its role in translational repression of Ard1b during spermatogenesis. Our results suggest that ARD1B may have an important role in the later course of the spermatogenic process. PMID:19246321

Cloning, characterization, and expression analysis of the novel acetyltransferase retrogene Ard1b in the mouse.

PubMed

Pang, Alan Lap-Yin; Peacock, Stephanie; Johnson, Warren; Bear, Deborah H; Rennert, Owen M; Chan, Wai-Yee

2009-08-01

N-alpha-terminal acetylation is a modification process that occurs cotranslationally on most eukaryotic proteins. The major enzyme responsible for this process, N-alpha-terminal acetyltransferase, is composed of the catalytic subunit ARD1A and the auxiliary subunit NAT1. We cloned, characterized, and studied the expression pattern of Ard1b (also known as Ard2), a novel homolog of the mouse Ard1a. Comparison of the genomic structures suggests that the autosomal Ard1b is a retroposed copy of the X-linked Ard1a. Expression analyses demonstrated a testis predominance of Ard1b. A reciprocal expression pattern between Ard1a and Ard1b is also observed during spermatogenesis, suggesting that Ard1b is expressed to compensate for the loss of Ard1a starting from meiosis. Both ARD1A and ARD1B can interact with NAT1 to constitute a functional N-alpha-terminal acetyltransferase in vitro. The expression of ARD1B protein can be detected in mouse testes but is delayed until the first appearance of round spermatids. In a cell culture model, the inclusion of the long 3' untranslated region of Ard1b leads to reduction of luciferase reporter activity, which implicates its role in translational repression of Ard1b during spermatogenesis. Our results suggest that ARD1B may have an important role in the later course of the spermatogenic process.

Presynaptic Proteins as Markers of the Neurotoxic Activity of BmjeTX-I and BmjeTX-II Toxins from Bothrops marajoensis (Marajó Lancehead) Snake Venom.

PubMed

Lisboa, Antonio; Melaré, Rodolfo; Franco, Junia R B; Bis, Carolina V; Gracia, Marta; Ponce-Soto, Luis A; Marangoni, Sérgio; Rodrigues-Simioni, Léa; da Cruz-Höfling, Maria Alice; Rocha, Thalita

2016-01-01

Neuromuscular preparations exposed to B. marajoensis venom show increases in the frequency of miniature end-plate potentials and twitch tension facilitation followed by presynaptic neuromuscular paralysis, without evidences of muscle damage. Considering that presynaptic toxins interfere into the machinery involved in neurotransmitter release (synaptophysin, synaptobrevin, and SNAP25 proteins), the main objective of this communication is to analyze, by immunofluorescence and western blotting, the expression of the synaptic proteins, synaptophysin, synaptobrevin, and SNAP25 and by myography, light, and transmission electron microscopy the pathology of motor nerve terminals and skeletal muscle fibres of chick biventer cervicis preparations (CBC) exposed in vitro to BmjeTX-I and BmjeTX-II toxins from B. marajoensis venom. CBC incubated with toxins showed irreversible twitch tension blockade and unaffected KCl- and ACh-evoked contractures, and the positive colabelling of acetylcholine receptors confirmed that their action was primarily at the motor nerve terminal. Hypercontraction and loose myofilaments and synaptic vesicle depletion and motor nerve damage indicated that the toxins displayed both myotoxic and neurotoxic effect. The blockade resulted from interference on synaptophysin, synaptobrevin, and SNAP25 proteins leading to the conclusion that BmjeTX-I and BmjeTX-II affected neurotransmitter release machinery by preventing the docking of synaptic vesicles to the axolemma of the nerve terminal.

Stimuli of Sensory-Motor Nerves Terminate Arterial Contractile Effects of Endothelin-1 by CGRP and Dissociation of ET-1/ETA-Receptor Complexes

PubMed Central

Meens, Merlijn J. P. M. T.; Compeer, Matthijs G.; Hackeng, Tilman M.; van Zandvoort, Marc A.; Janssen, Ben J. A.; De Mey, Jo G. R.

2010-01-01

Background Endothelin-1 (ET-1), a long-acting paracrine mediator, is implicated in cardiovascular diseases but clinical trials with ET-receptor antagonists were not successful in some areas. We tested whether the quasi-irreversible receptor-binding of ET-1 (i) limits reversing effects of the antagonists and (ii) can be selectively dissociated by an endogenous counterbalancing mechanism. Methodology/Principal findings In isolated rat mesenteric resistance arteries, ETA-antagonists, endothelium-derived relaxing factors and synthetic vasodilators transiently reduced contractile effects of ET-1 but did not prevent persistent effects of the peptide. Stimuli of peri-vascular vasodilator sensory-motor nerves such as capsaicin not only reduced but also terminated long-lasting effects of ET-1. This was prevented by CGRP-receptor antagonists and was mimicked by exogenous calcitonin gene-related peptide (CGRP). Using 2-photon laser scanning microscopy in vital intact arteries, capsaicin and CGRP, but not ETA-antagonism, were observed to promote dissociation of pre-existing ET-1/ETA-receptor complexes. Conclusions Irreversible binding and activation of ETA-receptors by ET-1 (i) occur at an antagonist-insensitive site of the receptor and (ii) are selectively terminated by endogenously released CGRP. Hence, natural stimuli of sensory-motor nerves that stimulate release of endogenous CGRP can be considered for therapy of diseases involving ET-1. PMID:20532232

Pharmacologic antagonism of dopamine receptor D3 attenuates neurodegeneration and motor impairment in a mouse model of Parkinson's disease.

PubMed

Elgueta, Daniela; Aymerich, María S; Contreras, Francisco; Montoya, Andro; Celorrio, Marta; Rojo-Bustamante, Estefanía; Riquelme, Eduardo; González, Hugo; Vásquez, Mónica; Franco, Rafael; Pacheco, Rodrigo

2017-02-01

Neuroinflammation involves the activation of glial cells, which is associated to the progression of neurodegeneration in Parkinson's disease. Recently, we and other researchers demonstrated that dopamine receptor D3 (D3R)-deficient mice are completely refractory to neuroinflammation and consequent neurodegeneration associated to the acute intoxication with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). In this study we examined the therapeutic potential and underlying mechanism of a D3R-selective antagonist, PG01037, in mice intoxicated with a chronic regime of administration of MPTP and probenecid (MPTPp). Biodistribution analysis indicated that intraperitoneally administered PG01037 crosses the blood-brain barrier and reaches the highest concentration in the brain 40 min after the injection. Furthermore, the drug was preferentially distributed to the brain in comparison to the plasma. Treatment of MPTPp-intoxicated mice with PG01037 (30 mg/kg, administrated twice a week for five weeks) attenuated the loss of dopaminergic neurons in the substantia nigra pars compacta, as evaluated by stereological analysis, and the loss of striatal dopaminergic terminals, as determined by densitometric analyses of tyrosine hydroxylase and dopamine transporter immunoreactivities. Accordingly, the treatment resulted in significant improvement of motor performance of injured animals. Interestingly, the therapeutic dose of PG01037 exacerbated astrogliosis and resulted in increased ramification density of microglial cells in the striatum of MPTPp-intoxicated mice. Further analyses suggested that D3R expressed in astrocytes favours a beneficial astrogliosis with anti-inflammatory consequences on microglia. Our findings indicate that D3R-antagonism exerts a therapeutic effect in parkinsonian animals by reducing the loss of dopaminergic neurons in the nigrostriatal pathway, alleviating motor impairments and modifying the pro-inflammatory phenotype of glial cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sensory neurons do not induce motor neuron loss in a human stem cell model of spinal muscular atrophy.

PubMed

Schwab, Andrew J; Ebert, Allison D

2014-01-01

Spinal muscular atrophy (SMA) is an autosomal recessive disorder leading to paralysis and early death due to reduced SMN protein. It is unclear why there is such a profound motor neuron loss, but recent evidence from fly and mouse studies indicate that cells comprising the whole sensory-motor circuit may contribute to motor neuron dysfunction and loss. Here, we used induced pluripotent stem cells derived from SMA patients to test whether sensory neurons directly contribute to motor neuron loss. We generated sensory neurons from SMA induced pluripotent stem cells and found no difference in neuron generation or survival, although there was a reduced calcium response to depolarizing stimuli. Using co-culture of SMA induced pluripotent stem cell derived sensory neurons with control induced pluripotent stem cell derived motor neurons, we found no significant reduction in motor neuron number or glutamate transporter boutons on motor neuron cell bodies or neurites. We conclude that SMA sensory neurons do not overtly contribute to motor neuron loss in this human stem cell system.

Endomicroscopy and electromyography of neuromuscular junctions in situ

PubMed Central

Brown, Rosalind; Dissanayake, Kosala N; Skehel, Paul A; Ribchester, Richard R

2014-01-01

Objective Electromyography (EMG) is used routinely to diagnose neuromuscular dysfunction in a wide range of peripheral neuropathies, myopathies, and neuromuscular degenerative diseases including motor neuron diseases such as amyotrophic lateral sclerosis (ALS). Definitive neurological diagnosis may also be indicated by the analysis of pathological neuromuscular innervation in motor-point biopsies. Our objective in this study was to preempt motor-point biopsy by combining live imaging with electrophysiological analysis of slow degeneration of neuromuscular junctions (NMJs) in vivo. Methods We combined conventional needle electromyography with fiber-optic confocal endomicroscopy (CEM), using an integrated hand-held, 1.5-mm-diameter probe. We utilized as a test bed, various axotomized muscles in the hind limbs of anaesthetized, double-homozygous thy1.2YFP16: WldS mice, which coexpress the Wallerian-degeneration Slow (WldS) protein and yellow fluorescent protein (YFP) in motor neurons. We also tested exogenous vital stains, including Alexa488-α-bungarotoxin; the styryl pyridinium dye 4-Di-2-Asp; and a GFP conjugate of botulinum toxin Type A heavy chain (GFP-HcBoNT/A). Results We show that an integrated EMG/CEM probe is effective in longitudinal evaluation of functional and morphological changes that take place over a 7-day period during axotomy-induced, slow neuromuscular synaptic degeneration. EMG amplitude declined in parallel with overt degeneration of motor nerve terminals. EMG/CEM was safe and effective when nerve terminals and motor endplates were selectively stained with vital dyes. Interpretation Our findings constitute proof-of-concept, based on live imaging in an animal model, that combining EMG/CEM may be useful as a minimally invasive precursor or alternative to motor-point biopsy in neurological diagnosis and for monitoring local administration of potential therapeutics. PMID:25540801

Reduced sensory synaptic excitation impairs motor neuron function via Kv2.1 in spinal muscular atrophy.

PubMed

Fletcher, Emily V; Simon, Christian M; Pagiazitis, John G; Chalif, Joshua I; Vukojicic, Aleksandra; Drobac, Estelle; Wang, Xiaojian; Mentis, George Z

2017-07-01

Behavioral deficits in neurodegenerative diseases are often attributed to the selective dysfunction of vulnerable neurons via cell-autonomous mechanisms. Although vulnerable neurons are embedded in neuronal circuits, the contributions of their synaptic partners to disease process are largely unknown. Here we show that, in a mouse model of spinal muscular atrophy (SMA), a reduction in proprioceptive synaptic drive leads to motor neuron dysfunction and motor behavior impairments. In SMA mice or after the blockade of proprioceptive synaptic transmission, we observed a decrease in the motor neuron firing that could be explained by the reduction in the expression of the potassium channel Kv2.1 at the surface of motor neurons. Chronically increasing neuronal activity pharmacologically in vivo led to a normalization of Kv2.1 expression and an improvement in motor function. Our results demonstrate a key role of excitatory synaptic drive in shaping the function of motor neurons during development and the contribution of its disruption to a neurodegenerative disease.

Reduced sensory synaptic excitation impairs motor neuron function via Kv2.1 in spinal muscular atrophy

PubMed Central

Fletcher, Emily V.; Simon, Christian M.; Pagiazitis, John G.; Chalif, Joshua I.; Vukojicic, Aleksandra; Drobac, Estelle; Wang, Xiaojian; Mentis, George Z.

2017-01-01

Behavioral deficits in neurodegenerative diseases are often attributed to the selective dysfunction of vulnerable neurons via cell-autonomous mechanisms. Although vulnerable neurons are embedded in neuronal circuits, the contribution of their synaptic partners to the disease process is largely unknown. Here, we show that in a mouse model of spinal muscular atrophy (SMA), a reduction in proprioceptive synaptic drive leads to motor neuron dysfunction and motor behavior impairments. In SMA mice or after the blockade of proprioceptive synaptic transmission we observed a decrease in the motor neuron firing which could be explained by the reduction in the expression of the potassium channel Kv2.1 at the surface of motor neurons. Increasing neuronal activity pharmacologically by chronic exposure in vivo led to a normalization of Kv2.1 expression and an improvement in motor function. Our results demonstrate a key role of excitatory synaptic drive in shaping the function of motor neurons during development and the contribution of its disruption to a neurodegenerative disease. PMID:28504671

A novel ALS-associated variant in UBQLN4 regulates motor axon morphogenesis.

PubMed

Edens, Brittany M; Yan, Jianhua; Miller, Nimrod; Deng, Han-Xiang; Siddique, Teepu; Ma, Yongchao C

2017-05-02

The etiological underpinnings of amyotrophic lateral sclerosis (ALS) are complex and incompletely understood, although contributions to pathogenesis by regulators of proteolytic pathways have become increasingly apparent. Here, we present a novel variant in UBQLN4 that is associated with ALS and show that its expression compromises motor axon morphogenesis in mouse motor neurons and in zebrafish. We further demonstrate that the ALS-associated UBQLN4 variant impairs proteasomal function, and identify the Wnt signaling pathway effector beta-catenin as a UBQLN4 substrate. Inhibition of beta-catenin function rescues the UBQLN4 variant-induced motor axon phenotypes. These findings provide a strong link between the regulation of axonal morphogenesis and a new ALS-associated gene variant mediated by protein degradation pathways.

Degeneration of Phrenic Motor Neurons Induces Long-Term Diaphragm Deficits following Mid-Cervical Spinal Contusion in Mice

PubMed Central

Nicaise, Charles; Putatunda, Rajarshi; Hala, Tamara J.; Regan, Kathleen A.; Frank, David M.; Brion, Jean-Pierre; Leroy, Karelle; Pochet, Roland; Wright, Megan C.

2012-01-01

Abstract A primary cause of morbidity and mortality following cervical spinal cord injury (SCI) is respiratory compromise, regardless of the level of trauma. In particular, SCI at mid-cervical regions targets degeneration of both descending bulbospinal respiratory axons and cell bodies of phrenic motor neurons, resulting in deficits in the function of the diaphragm, the primary muscle of inspiration. Contusion-type trauma to the cervical spinal cord is one of the most common forms of human SCI; however, few studies have evaluated mid-cervical contusion in animal models or characterized consequent histopathological and functional effects of degeneration of phrenic motor neuron–diaphragm circuitry. We have generated a mouse model of cervical contusion SCI that unilaterally targets both C4 and C5 levels, the location of the phrenic motor neuron pool, and have examined histological and functional outcomes for up to 6 weeks post-injury. We report that phrenic motor neuron loss in cervical spinal cord, phrenic nerve axonal degeneration, and denervation at diaphragm neuromuscular junctions (NMJ) resulted in compromised ipsilateral diaphragm function, as demonstrated by persistent reduction in diaphragm compound muscle action potential amplitudes following phrenic nerve stimulation and abnormalities in spontaneous diaphragm electromyography (EMG) recordings. This injury paradigm is reproducible, does not require ventilatory assistance, and provides proof-of-principle that generation of unilateral cervical contusion is a feasible strategy for modeling diaphragmatic/respiratory deficits in mice. This study and its accompanying analyses pave the way for using transgenic mouse technology to explore the function of specific genes in the pathophysiology of phrenic motor neuron degeneration and respiratory dysfunction following cervical SCI. PMID:23176637

Alpha-Synuclein Pathology in Sensory Nerve Terminals of the Upper Aerodigestive Tract of Parkinson’s Disease Patients

PubMed Central

Mu, Liancai; Chen, Jingming; Sobotka, Stanislaw; Nyirenda, Themba; Benson, Brian; Gupta, Fiona; Sanders, Ira; Adler, Charles H.; Caviness, John N.; Shill, Holly A.; Sabbagh, Marwan; Samanta, Johan E.; Sue, Lucia I.; Beach, Thomas G.

2015-01-01

Dysphagia is common in Parkinson’s disease (PD) and causes significant morbidity and mortality. PD dysphagia has usually been explained as dysfunction of central motor control, much like other motor symptoms that are characteristic of the disease. However, PD dysphagia does not correlate with severity of motor symptoms nor does it respond to motor therapies. It is known that PD patients have sensory deficits in the pharynx, and that impaired sensation may contribute to dysphagia. However, the underlying cause of the pharyngeal sensory deficits in PD is not known. We hypothesized that PD dysphagia with sensory deficits may be due to degeneration of the sensory nerve terminals in the upper aerodigestive tract (UAT). We have previously shown that Lewy-type synucleinopathy (LTS) is present in the main pharyngeal sensory nerves of PD patients, but not in controls. In this study, the sensory terminals in UAT mucosa were studied to discern the presence and distribution of LTS. Whole-mount specimens (tongue-pharynx-larynx-upper esophagus) were obtained from 10 deceased human subjects with clinically diagnosed and neuropathologically confirmed PD (five with dysphagia and five without) and four age-matched healthy controls. Samples were taken from six sites and immunostained for phosphorylated α-synuclein (PAS). The results showed the presence of PAS-immunoreactive (PAS-ir) axons in all the PD subjects and in none of the controls. Notably, PD patients with dysphagia had more PAS-ir axons in the regions that are critical for initiating the swallowing reflex. These findings suggest that Lewy pathology affects mucosal sensory axons in specific regions of the UAT and may be related to PD dysphagia. PMID:26041249

Alpha-Synuclein Pathology in Sensory Nerve Terminals of the Upper Aerodigestive Tract of Parkinson's Disease Patients.

PubMed

Mu, Liancai; Chen, Jingming; Sobotka, Stanislaw; Nyirenda, Themba; Benson, Brian; Gupta, Fiona; Sanders, Ira; Adler, Charles H; Caviness, John N; Shill, Holly A; Sabbagh, Marwan; Samanta, Johan E; Sue, Lucia I; Beach, Thomas G

2015-08-01

Dysphagia is common in Parkinson's disease (PD) and causes significant morbidity and mortality. PD dysphagia has usually been explained as dysfunction of central motor control, much like other motor symptoms that are characteristic of the disease. However, PD dysphagia does not correlate with severity of motor symptoms nor does it respond to motor therapies. It is known that PD patients have sensory deficits in the pharynx, and that impaired sensation may contribute to dysphagia. However, the underlying cause of the pharyngeal sensory deficits in PD is not known. We hypothesized that PD dysphagia with sensory deficits may be due to degeneration of the sensory nerve terminals in the upper aerodigestive tract (UAT). We have previously shown that Lewy-type synucleinopathy (LTS) is present in the main pharyngeal sensory nerves of PD patients, but not in controls. In this study, the sensory terminals in UAT mucosa were studied to discern the presence and distribution of LTS. Whole-mount specimens (tongue-pharynx-larynx-upper esophagus) were obtained from 10 deceased human subjects with clinically diagnosed and neuropathologically confirmed PD (five with dysphagia and five without) and four age-matched healthy controls. Samples were taken from six sites and immunostained for phosphorylated α-synuclein (PAS). The results showed the presence of PAS-immunoreactive (PAS-ir) axons in all the PD subjects and in none of the controls. Notably, PD patients with dysphagia had more PAS-ir axons in the regions that are critical for initiating the swallowing reflex. These findings suggest that Lewy pathology affects mucosal sensory axons in specific regions of the UAT and may be related to PD dysphagia.

Ultrastructural and molecular biologic comparison of classic proprioceptors and palisade endings in sheep extraocular muscles.

PubMed

Rungaldier, Stefanie; Heiligenbrunner, Stefan; Mayer, Regina; Hanefl-Krivanek, Christiane; Lipowec, Marietta; Streicher, Johannes; Blumer, Roland

2009-12-01

To analyze and compare the structural and molecular features of classic proprioceptors like muscle spindles and Golgi tendon organs (GTOs) and putative proprioceptors (palisade endings) in sheep extraocular muscle (EOMs). The EOMs of four sheep were analyzed. Frozen sections or wholemount preparations of the samples were immunohistochemically labeled and analyzed by confocal laser scanning microscopy. Triple labeling with different combinations of antibodies against neurofilament, synaptophysin, and choline acetyltransferase (ChAT), as well as alpha-bungarotoxin and phalloidin, was performed. Microscopic anatomy of the nerve end organs was analyzed by transmission electron microscopy. The microscopic anatomy demonstrated that muscle spindles and GTOs had a perineural capsule and palisade endings a connective tissue capsule. Sensory nerve terminals in muscle spindles and GTOs contained only a few vesicles, whereas palisade nerve terminals were full of clear vesicles. Likewise, motor terminals in the muscle spindles' polar regions were full of clear vesicles. Immunohistochemistry showed that sensory nerve fibers as well as their sensory nerve terminals in muscle spindles and GTOs were ChAT-negative. Palisade endings were supplied by ChAT-positive nerve fibers, and the palisade complexes including palisade nerve terminals were also ChAT-immunoreactive. Motor terminals in muscle spindles were ChAT and alpha-bungarotoxin positive. The present study demonstrated in sheep EOMs that palisade endings are innervated by cholinergic axons exhibiting characteristics typical of motoneurons, whereas muscle spindles (except the polar regions) and GTOs are supplied by noncholinergic axons. These results raise the question of whether palisade endings are candidates for proprioceptors in EOMs.

Ultrastructural and molecular biologic comparison of classical proprioceptors and palisade endings in sheep extraocular muscles

PubMed Central

RUNGALDIER, Stefanie; HEILIGENBRUNNER, Stefan; MAYER, Regina; HANEFL-KRIVANEK, Christiane; LIPOWEC, Marietta; STREICHER, Johannes; BLUMER, Roland

2016-01-01

Purpose To analyze and compare the structural and molecular features of classical proprioceptors like muscle spindles and Golgi tendon organs (GTOs) and putative proprioceptors (palisade endings) in sheep extraocular muscle (EOMs). Methods The EOMs of four sheep were analyzed. Frozen sections or whole mount preparations of the samples were immunohistochemically labeled and analyzed by confocal laser scanning microscopy. Triple labeling with different combinations of antibodies against neurofilament, synaptophysin and choline acetyltransferase (ChAT) as well as α-bungarotoxin and phalloidin was performed. Microscopic anatomy of the nerve end organs was analyzed by transmission electron microscopy. Results The microscopic anatomy demonstrated that muscle spindles and GTOs had a perineural capsule and palisade endings a connective tissue capsule. Sensory nerve terminals in muscle spindles and GTOs contained only few vesicles whereas palisade nerve terminals were full of clear vesicles. Likewise, motor terminals in the muscle spindles’ polar regions were full of clear vesicles. Immunohistochemistry showed that sensory nerve fibers as well as their sensory nerve terminals in muscle spindles and GTOs were ChAT-negative. Palisade endings were supplied by ChAT-positive nerve fibers and the palisade complexes including palisade nerve terminals were also ChAT-immunoreactive. Motor terminals in muscle spindles were ChAT and α-bungarotoxin -positive. Conclusions The present study demonstrated in sheep EOMs that palisade endings are innervated by cholinergic axons exhibiting characteristics typical for motoneurons whereas muscle spindles (except the polar regions) and GTOs are supplied by non-cholinergic axons. These results question whether palisade endings are candidates for proprioceptors in EOMs. PMID:19553627

Cytoarchitecture of the spinal cord of the postnatal (P4) mouse.

PubMed

Sengul, Gulgun; Puchalski, Ralph B; Watson, Charles

2012-05-01

Interpretation of the new wealth of gene expression and molecular mechanisms in the developing mouse spinal cord requires an accurate anatomical base on which data can be mapped. Therefore, we have assembled a spinal cord atlas of the P4 mouse to facilitate direct comparison with the adult specimens and to contribute to studies of the development of the mouse spinal cord. This study presents the anatomy of the spinal cord of the P4 C57Bl/6J mouse using Nissl and acetyl cholinesterase-stained sections. It includes a detailed map of the laminar organization of selected spinal cord segments and a description of named cell groups of the spinal cord such as the central cervical (CeCv), lateral spinal nucleus, lateral cervical, and dorsal nuclei. The motor neuron groups have also been identified according to the muscle groups they are likely to supply. General features of Rexed's laminae of the P4 spinal cord showed similarities to that of the adult (P56). However, certain differences were observed with regard to the extent of laminae and location of certain cell groups, such as the dorsal nucleus having a more dispersed structure and a more ventral and medial position or the CeCv being located in the medial part of lamina 5 in contrast to the adult where it is located in lamina 7. Motor neuron pools appeared to be more tightly packed in the P4 spinal cord. The dorsal horn was relatively larger and there was more white matter in the P56 spinal cord. Copyright © 2012 Wiley Periodicals, Inc.

Expression and purification of active mouse and human NEIL3 proteins

PubMed Central

Liu, Minmin; Bandaru, Viswanath; Holmes, Alicia; Averill, April M.; Cannan, Wendy

2012-01-01

Endonuclease VIII-like 3 (Neil3) is one of the five DNA glycosylases found in mammals that recognize and remove oxidized bases, and initiate the Base Excision Repair (BER) pathway. Previous attempts to express and purify the mouse and human orthologs of Neil3 in their active form have not been successful. Here we report the construction of bicistronic expression vectors for expressing in Escherichia coli the full-length mouse Neil3 (MmuNeil3), its glycosylase domain (MmuNeil3Δ324), as well as the glycosylase domain of human Neil3 (NEIL3Δ324). The purified Neil3 proteins are all active, and NEIL3Δ324 exhibits similar glycosylase/lyase activity as MmuNeil3Δ324 on both single-stranded and double-stranded substrates containing thymine glycol (Tg), spiroiminodihydantoin (Sp) or an abasic site (AP). We show that N-terminal initiator methionine processing is critical for the activity of both mouse and human Neil3 proteins. Co-expressing an E. coli methionine aminopeptidase (EcoMap) Y168A variant with MmuNeil3, MmuNeil3Δ324 and NEIL3Δ324 improves the N-terminal methionine processing and increases the percentage of active Neil3 proteins in the preparation. The purified Neil3 proteins are suitable for biochemical, structural and functional studies. PMID:22569481

Comprehensive Identification of Krüppel-Like Factor Family Members Contributing to the Self-Renewal of Mouse Embryonic Stem Cells and Cellular Reprogramming.

PubMed

Jeon, Hyojung; Waku, Tsuyoshi; Azami, Takuya; Khoa, Le Tran Phuc; Yanagisawa, Jun; Takahashi, Satoru; Ema, Masatsugu

2016-01-01

Pluripotency is maintained in mouse embryonic stem (ES) cells and is induced from somatic cells by the activation of appropriate transcriptional regulatory networks. Krüppel-like factor gene family members, such as Klf2, Klf4 and Klf5, have important roles in maintaining the undifferentiated state of mouse ES cells as well as in cellular reprogramming, yet it is not known whether other Klf family members exert self-renewal and reprogramming functions when overexpressed. In this study, we examined whether overexpression of any representative Klf family member, such as Klf1-Klf10, would be sufficient for the self-renewal of mouse ES cells. We found that only Klf2, Klf4, and Klf5 produced leukemia inhibitory factor (LIF)-independent self-renewal, although most KLF proteins, if not all, have the ability to occupy the regulatory regions of Nanog, a critical Klf target gene. We also examined whether overexpression of any of Klf1-Klf10 would be sufficient to convert epiblast stem cells into a naïve pluripotent state and found that Klf5 had such reprogramming ability, in addition to Klf2 and Klf4. We also delineated the functional domains of the Klf2 protein for LIF-independent self-renewal and reprogramming. Interestingly, we found that both the N-terminal transcriptional activation and C-terminal zinc finger domains were indispensable for this activity. Taken together, our comprehensive analysis provides new insight into the contribution of Klf family members to mouse ES self-renewal and cellular reprogramming.

Detectability of Delaminations in Solid Rocket Motors with Embedded Stress Sensors

DTIC Science & Technology

2011-10-14

composite grain of hydroxyl-terminated polybutadiene/ammonium perchlorate (HTPB/AP). The insulation layer is ethylene propylene diene monomer ( EPDM ...The temperature-dependent mechanical properties of HTPB/AP and EPDM were obtained from in-house testing at AFRL/RZSM (Edwards AFB). The motor case is...temperature (DBST) sensors and Greg Yandek of AFRL/RZSM for the data collection of EPDM insulation material. Distribution A: Approved for public

Kinesin Mutations Cause Motor Neuron Disease Phenotypes by Disrupting Fast Axonal Transport in Drosophila

PubMed Central

Hurd, D. D.; Saxton, W. M.

1996-01-01

Previous work has shown that mutation of the gene that encodes the microtubule motor subunit kinesin heavy chain (Khc) in Drosophila inhibits neuronal sodium channel activity, action potentials and neurotransmitter secretion. These physiological defects cause progressive distal paralysis in larvae. To identify the cellular defects that cause these phenotypes, larval nerves were studied by light and electron microscopy. The axons of Khc mutants develop dramatic focal swellings along their lengths. The swellings are packed with fast axonal transport cargoes including vesicles, synaptic membrane proteins, mitochondria and prelysosomal organelles, but not with slow axonal transport cargoes such as cytoskeletal elements. Khc mutations also impair the development of larval motor axon terminals, causing dystrophic morphology and marked reductions in synaptic bouton numbers. These observations suggest that as the concentration of maternally provided wild-type KHC decreases, axonal organelles transported by kinesin periodically stall. This causes organelle jams that disrupt retrograde as well as anterograde fast axonal transport, leading to defective action potentials, dystrophic terminals, reduced transmitter secretion and progressive distal paralysis. These phenotypes parallel the pathologies of some vertebrate motor neuron diseases, including some forms of amyotrophic lateral sclerosis (ALS), and suggest that impaired fast axonal transport is a key element in those diseases. PMID:8913751

Dissociation between behavior and motor cortical excitability before and during ballistic wrist flexion and extension in young and old adults.

PubMed

Hortobágyi, Tibor; Mieras, Adinda; Rothwell, John; Del Olmo, Miguel Fernandez

2017-01-01

Aging is associated with slow reactive movement generation and poor termination. We examined the hypothesis that the build-up of excitability in the primary motor cortex in the agonist muscle to generate ballistic wrist flexion and extension and in the antagonist to stop the movement, is lower and slower in old compared with young adults. We measured the size of the motor potentials evoked (MEP) produced by transcranial magnetic stimulation (TMS), background integrated EMG (iEMG), and the MEP:iEMG ratio in healthy young (23 y, n = 14) and old adults' (73 y, n = 14) wrist flexors and extensors as they rapidly flexed or extended the wrist in response to an auditory cue. TMS was delivered at 80% of resting motor threshold randomly in 20 ms increments between 130 and 430 ms after the tone. Even though old compared to young adults executed the two wrist movements with ~23% longer movement duration and ~15% longer reaction time (both p < 0.05), the rise in MEP:iEMG ratio before the main similar in the two age groups. These data suggest that an adjustment of current models might be needed to better understand how and if age affects the build-up excitability accompanying movement generation and termination.

Early motor deficits in mouse disease models are reliably uncovered using an automated home-cage wheel-running system: a cross-laboratory validation.

PubMed

Mandillo, Silvia; Heise, Ines; Garbugino, Luciana; Tocchini-Valentini, Glauco P; Giuliani, Alessandro; Wells, Sara; Nolan, Patrick M

2014-03-01

Deficits in motor function are debilitating features in disorders affecting neurological, neuromuscular and musculoskeletal systems. Although these disorders can vary greatly with respect to age of onset, symptomatic presentation, rate of progression and severity, the study of these disease models in mice is confined to the use of a small number of tests, most commonly the rotarod test. To expand the repertoire of meaningful motor function tests in mice, we tested, optimised and validated an automated home-cage-based running-wheel system, incorporating a conventional wheel with evenly spaced rungs and a complex wheel with particular rungs absent. The system enables automated assessment of motor function without handler interference, which is desirable in longitudinal studies involving continuous monitoring of motor performance. In baseline studies at two test centres, consistently significant differences in performance on both wheels were detectable among four commonly used inbred strains. As further validation, we studied performance in mutant models of progressive neurodegenerative diseases--Huntington's disease [TgN(HD82Gln)81Dbo; referred to as HD mice] and amyotrophic lateral sclerosis [Tg(SOD1G93A)(dl)1/GurJ; referred to as SOD1 mice]--and in a mutant strain with subtle gait abnormalities, C-Snap25(Bdr)/H (Blind-drunk, Bdr). In both models of progressive disease, as with the third mutant, we could reliably and consistently detect specific motor function deficits at ages far earlier than any previously recorded symptoms in vivo: 7-8 weeks for the HD mice and 12 weeks for the SOD1 mice. We also conducted longitudinal analysis of rotarod and grip strength performance, for which deficits were still not detectable at 12 weeks and 23 weeks, respectively. Several new parameters of motor behaviour were uncovered using principal component analysis, indicating that the wheel-running assay could record features of motor function that are independent of rotarod performance. This represents a powerful new method to detect motor deficits at pre-symptomatic stages in mouse disease models and should be considered as a valid tool to investigate the efficacy of therapeutic agents.

Early motor deficits in mouse disease models are reliably uncovered using an automated home-cage wheel-running system: a cross-laboratory validation

PubMed Central

Mandillo, Silvia; Heise, Ines; Garbugino, Luciana; Tocchini-Valentini, Glauco P.; Giuliani, Alessandro; Wells, Sara; Nolan, Patrick M.

2014-01-01

Deficits in motor function are debilitating features in disorders affecting neurological, neuromuscular and musculoskeletal systems. Although these disorders can vary greatly with respect to age of onset, symptomatic presentation, rate of progression and severity, the study of these disease models in mice is confined to the use of a small number of tests, most commonly the rotarod test. To expand the repertoire of meaningful motor function tests in mice, we tested, optimised and validated an automated home-cage-based running-wheel system, incorporating a conventional wheel with evenly spaced rungs and a complex wheel with particular rungs absent. The system enables automated assessment of motor function without handler interference, which is desirable in longitudinal studies involving continuous monitoring of motor performance. In baseline studies at two test centres, consistently significant differences in performance on both wheels were detectable among four commonly used inbred strains. As further validation, we studied performance in mutant models of progressive neurodegenerative diseases – Huntington’s disease [TgN(HD82Gln)81Dbo; referred to as HD mice] and amyotrophic lateral sclerosis [Tg(SOD1G93A)dl1/GurJ; referred to as SOD1 mice] – and in a mutant strain with subtle gait abnormalities, C-Snap25Bdr/H (Blind-drunk, Bdr). In both models of progressive disease, as with the third mutant, we could reliably and consistently detect specific motor function deficits at ages far earlier than any previously recorded symptoms in vivo: 7–8 weeks for the HD mice and 12 weeks for the SOD1 mice. We also conducted longitudinal analysis of rotarod and grip strength performance, for which deficits were still not detectable at 12 weeks and 23 weeks, respectively. Several new parameters of motor behaviour were uncovered using principal component analysis, indicating that the wheel-running assay could record features of motor function that are independent of rotarod performance. This represents a powerful new method to detect motor deficits at pre-symptomatic stages in mouse disease models and should be considered as a valid tool to investigate the efficacy of therapeutic agents. PMID:24423792

Of Mice, Birds, and Men: The Mouse Ultrasonic Song System Has Some Features Similar to Humans and Song-Learning Birds

PubMed Central

Arriaga, Gustavo; Zhou, Eric P.; Jarvis, Erich D.

2012-01-01

Humans and song-learning birds communicate acoustically using learned vocalizations. The characteristic features of this social communication behavior include vocal control by forebrain motor areas, a direct cortical projection to brainstem vocal motor neurons, and dependence on auditory feedback to develop and maintain learned vocalizations. These features have so far not been found in closely related primate and avian species that do not learn vocalizations. Male mice produce courtship ultrasonic vocalizations with acoustic features similar to songs of song-learning birds. However, it is assumed that mice lack a forebrain system for vocal modification and that their ultrasonic vocalizations are innate. Here we investigated the mouse song system and discovered that it includes a motor cortex region active during singing, that projects directly to brainstem vocal motor neurons and is necessary for keeping song more stereotyped and on pitch. We also discovered that male mice depend on auditory feedback to maintain some ultrasonic song features, and that sub-strains with differences in their songs can match each other's pitch when cross-housed under competitive social conditions. We conclude that male mice have some limited vocal modification abilities with at least some neuroanatomical features thought to be unique to humans and song-learning birds. To explain our findings, we propose a continuum hypothesis of vocal learning. PMID:23071596

An anticholinergic reverses motor control and corticostriatal LTD deficits in Dyt1 ΔGAG knock-in mice.

PubMed

Dang, Mai T; Yokoi, Fumiaki; Cheetham, Chad C; Lu, Jun; Vo, Viet; Lovinger, David M; Li, Yuqing

2012-01-15

DYT1 early-onset generalized torsion dystonia is an inherited movement disorder associated with mutations in DYT1 that codes for torsinA protein. The most common mutation seen in this gene is a trinucleotide deletion of GAG. We previously reported a motor control deficit on a beam-walking task in our Dyt1 ΔGAG knock-in heterozygous mice. In this report we show the reversal of this motor deficit with the anticholinergic trihexyphenidyl (THP), a drug commonly used to treat movement problems in dystonia patients. THP also restored the reduced corticostriatal long-term depression (LTD) observed in these mice. Corticostriatal LTD has long been known to be dependent on D2 receptor activation. In this mouse model, striatal D2 receptors were expressed at lower quantities in comparison to wild-type mice. Furthermore, the mice were also partially resistant to FPL64176, an agonist of L-type calcium channels that have been previously reported to cause severe dystonic-like symptoms in wild-type mice. Our findings collectively suggest that altered communication between cholinergic interneurons and medium spiny neurons is responsible for the LTD deficit and that this synaptic plasticity modification may be involved in the striatal motor control abnormalities in our mouse model of DYT1 dystonia. Copyright © 2011 Elsevier B.V. All rights reserved.

Loss of Mitochondrial Ndufs4 in Striatal Medium Spiny Neurons Mediates Progressive Motor Impairment in a Mouse Model of Leigh Syndrome.

PubMed

Chen, Byron; Hui, Jessica; Montgomery, Kelsey S; Gella, Alejandro; Bolea, Irene; Sanz, Elisenda; Palmiter, Richard D; Quintana, Albert

2017-01-01

Inability of mitochondria to generate energy leads to severe and often fatal myoencephalopathies. Among these, Leigh syndrome (LS) is one of the most common childhood mitochondrial diseases; it is characterized by hypotonia, failure to thrive, respiratory insufficiency and progressive mental and motor dysfunction, leading to early death. Basal ganglia nuclei, including the striatum, are affected in LS patients. However, neither the identity of the affected cell types in the striatum nor their contribution to the disease has been established. Here, we used a mouse model of LS lacking Ndufs4 , a mitochondrial complex I subunit, to confirm that loss of complex I, but not complex II, alters respiration in the striatum. To assess the role of striatal dysfunction in the pathology, we selectively inactivated Ndufs4 in the striatal medium spiny neurons (MSNs), which account for over 95% of striatal neurons. Our results show that lack of Ndufs4 in MSNs causes a non-fatal progressive motor impairment without affecting the cognitive function of mice. Furthermore, no inflammatory responses or neuronal loss were observed up to 6 months of age. Hence, complex I deficiency in MSNs contributes to the motor deficits observed in LS, but not to the neural degeneration, suggesting that other neuronal populations drive the plethora of clinical signs in LS.

The C-terminal heavy-chain domain of botulinum neurotoxin a is not the only site that binds neurons, as the N-terminal heavy-chain domain also plays a very active role in toxin-cell binding and interactions.

PubMed

Ayyar, B Vijayalakshmi; Aoki, K Roger; Atassi, M Zouhair

2015-04-01

Botulinum neurotoxins (BoNTs) possess unique specificity for nerve terminals. They bind to the presynaptic membrane and then translocate intracellularly, where the light-chain endopeptidase cleaves the SNARE complex proteins, subverting the synaptic exocytosis responsible for acetylcholine release to the synaptic cleft. This inhibits acetylcholine binding to its receptor, causing paralysis. Binding, an obligate event for cell intoxication, is believed to occur through the heavy-chain C-terminal (HC) domain. It is followed by toxin translocation and entry into the cell cytoplasm, which is thought to be mediated by the heavy-chain N-terminal (HN) domain. Submolecular mapping analysis by using synthetic peptides spanning BoNT serotype A (BoNT/A) and mouse brain synaptosomes (SNPs) and protective antibodies against toxin from mice and cervical dystonia patients undergoing BoNT/A treatment revealed that not only regions of the HC domain but also regions of the HN domain are involved in the toxin binding process. Based on these findings, we expressed a peptide corresponding to the BoNT/A region comprising HN domain residues 729 to 845 (HN729-845). HN729-845 bound directly to mouse brain SNPs and substantially inhibited BoNT/A binding to SNPs. The binding involved gangliosides GT1b and GD1a and a few membrane lipids. The peptide bound to human or mouse neuroblastoma cells within 1 min. Peptide HN729-845 protected mice completely against a lethal BoNT/A dose (1.05 times the 100% lethal dose). This protective activity was obtained at a dose comparable to that of the peptide from positions 967 to 1296 in the HC domain. These findings strongly indicate that HN729-845 and, by extension, the HN domain are fully programmed and equipped to bind to neuronal cells and in the free state can even inhibit the binding of the toxin. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Selective Deletion of Sodium Salt Taste during Development Leads to Expanded Terminal Fields of Gustatory Nerves in the Adult Mouse Nucleus of the Solitary Tract.

PubMed

Sun, Chengsan; Hummler, Edith; Hill, David L

2017-01-18

Neuronal activity plays a key role in the development of sensory circuits in the mammalian brain. In the gustatory system, experimental manipulations now exist, through genetic manipulations of specific taste transduction processes, to examine how specific taste qualities (i.e., basic tastes) impact the functional and structural development of gustatory circuits. Here, we used a mouse knock-out model in which the transduction component used to discriminate sodium salts from other taste stimuli was deleted in taste bud cells throughout development. We used this model to test the hypothesis that the lack of activity elicited by sodium salt taste impacts the terminal field organization of nerves that carry taste information from taste buds to the nucleus of the solitary tract (NST) in the medulla. The glossopharyngeal, chorda tympani, and greater superficial petrosal nerves were labeled to examine their terminal fields in adult control mice and in adult mice in which the α-subunit of the epithelial sodium channel was conditionally deleted in taste buds (αENaC knockout). The terminal fields of all three nerves in the NST were up to 2.7 times greater in αENaC knock-out mice compared with the respective field volumes in control mice. The shapes of the fields were similar between the two groups; however, the density and spread of labels were greater in αENaC knock-out mice. Overall, our results show that disruption of the afferent taste signal to sodium salts disrupts the normal age-dependent "pruning" of all terminal fields, which could lead to alterations in sensory coding and taste-related behaviors. Neural activity plays a major role in the development of sensory circuits in the mammalian brain. To date, there has been no direct test of whether taste-elicited neural activity has a role in shaping central gustatory circuits. However, recently developed genetic tools now allow an assessment of how specific taste stimuli, in this case sodium salt taste, play a role in the maturation of the terminal fields in the mouse brainstem. We found that the specific deletion of sodium salt taste during development produced terminal fields in adults that were dramatically larger than in control mice, demonstrating for the first time that sodium salt taste-elicited activity is necessary for the normal maturation of gustatory inputs into the brain. Copyright © 2017 the authors 0270-6474/17/370660-13$15.00/0.

Selective Deletion of Sodium Salt Taste during Development Leads to Expanded Terminal Fields of Gustatory Nerves in the Adult Mouse Nucleus of the Solitary Tract

PubMed Central

Sun, Chengsan; Hummler, Edith

2017-01-01

Neuronal activity plays a key role in the development of sensory circuits in the mammalian brain. In the gustatory system, experimental manipulations now exist, through genetic manipulations of specific taste transduction processes, to examine how specific taste qualities (i.e., basic tastes) impact the functional and structural development of gustatory circuits. Here, we used a mouse knock-out model in which the transduction component used to discriminate sodium salts from other taste stimuli was deleted in taste bud cells throughout development. We used this model to test the hypothesis that the lack of activity elicited by sodium salt taste impacts the terminal field organization of nerves that carry taste information from taste buds to the nucleus of the solitary tract (NST) in the medulla. The glossopharyngeal, chorda tympani, and greater superficial petrosal nerves were labeled to examine their terminal fields in adult control mice and in adult mice in which the α-subunit of the epithelial sodium channel was conditionally deleted in taste buds (αENaC knockout). The terminal fields of all three nerves in the NST were up to 2.7 times greater in αENaC knock-out mice compared with the respective field volumes in control mice. The shapes of the fields were similar between the two groups; however, the density and spread of labels were greater in αENaC knock-out mice. Overall, our results show that disruption of the afferent taste signal to sodium salts disrupts the normal age-dependent “pruning” of all terminal fields, which could lead to alterations in sensory coding and taste-related behaviors. SIGNIFICANCE STATEMENT Neural activity plays a major role in the development of sensory circuits in the mammalian brain. To date, there has been no direct test of whether taste-elicited neural activity has a role in shaping central gustatory circuits. However, recently developed genetic tools now allow an assessment of how specific taste stimuli, in this case sodium salt taste, play a role in the maturation of the terminal fields in the mouse brainstem. We found that the specific deletion of sodium salt taste during development produced terminal fields in adults that were dramatically larger than in control mice, demonstrating for the first time that sodium salt taste-elicited activity is necessary for the normal maturation of gustatory inputs into the brain. PMID:28100747

A C-terminal HSP90 inhibitor restores glucocorticoid sensitivity and relieves a mouse allograft model of Cushing disease.

PubMed

Riebold, Mathias; Kozany, Christian; Freiburger, Lee; Sattler, Michael; Buchfelder, Michael; Hausch, Felix; Stalla, Günter K; Paez-Pereda, Marcelo

2015-03-01

One function of the glucocorticoid receptor (GR) in corticotroph cells is to suppress the transcription of the gene encoding proopiomelanocortin (POMC), the precursor of the stress hormone adrenocorticotropin (ACTH). Cushing disease is a neuroendocrine condition caused by partially glucocorticoid-resistant corticotroph adenomas that excessively secrete ACTH, which leads to hypercortisolism. Mutations that impair GR function explain glucocorticoid resistance only in sporadic cases. However, the proper folding of GR depends on direct interactions with the chaperone heat shock protein 90 (HSP90, refs. 7,8). We show here that corticotroph adenomas overexpress HSP90 compared to the normal pituitary. N- and C-terminal HSP90 inhibitors act at different steps of the HSP90 catalytic cycle to regulate corticotroph cell proliferation and GR transcriptional activity. C-terminal inhibitors cause the release of mature GR from HSP90, which promotes its exit from the chaperone cycle and potentiates its transcriptional activity in a corticotroph cell line and in primary cultures of human corticotroph adenomas. In an allograft mouse model, the C-terminal HSP90 inhibitor silibinin showed anti-tumorigenic effects, partially reverted hormonal alterations, and alleviated symptoms of Cushing disease. These results suggest that the pathogenesis of Cushing disease caused by overexpression of heat shock proteins and consequently misregulated GR sensitivity may be overcome pharmacologically with an appropriate HSP90 inhibitor.

The 'glial' glutamate transporter, EAAT2 (Glt-1) accounts for high affinity glutamate uptake into adult rodent nerve endings.

PubMed

Suchak, Sachin K; Baloyianni, Nicoletta V; Perkinton, Michael S; Williams, Robert J; Meldrum, Brian S; Rattray, Marcus

2003-02-01

The excitatory amino acid transporters (EAAT) removes neurotransmitters glutamate and aspartate from the synaptic cleft. Most CNS glutamate uptake is mediated by EAAT2 into glia, though nerve terminals show evidence for uptake, through an unknown transporter. Reverse-transcriptase PCR identified the expression of EAAT1, EAAT2, EAAT3 and EAAT4 mRNAs in primary cultures of mouse cortical or striatal neurones. We have used synaptosomes and glial plasmalemmal vesicles (GPV) from adult mouse and rat CNS to identify the nerve terminal transporter. Western blotting showed detectable levels of the transporters EAAT1 (GLAST) and EAAT2 (Glt-1) in both synaptosomes and GPVs. Uptake of [3H]D-aspartate or [3H]L-glutamate into these preparations revealed sodium-dependent uptake in GPV and synaptosomes which was inhibited by a range of EAAT blockers: dihydrokainate, serine-o-sulfate, l-trans-2,4-pyrrolidine dicarboxylate (PDC) (+/-)-threo-3-methylglutamate and (2S,4R )-4-methylglutamate. The IC50 values found for these compounds suggested functional expression of the 'glial, transporter, EAAT2 in nerve terminals. Additionally blockade of the majority EAAT2 uptake sites with 100 micro m dihydrokainate, failed to unmask any functional non-EAAT2 uptake sites. The data presented in this study indicate that EAAT2 is the predominant nerve terminal glutamate transporter in the adult rodent CNS.

Dual interaction of scaffold protein Tim44 of mitochondrial import motor with channel-forming translocase subunit Tim23

PubMed Central

Ting, See-Yeun; Yan, Nicholas L; Schilke, Brenda A; Craig, Elizabeth A

2017-01-01

Proteins destined for the mitochondrial matrix are targeted to the inner membrane Tim17/23 translocon by their presequences. Inward movement is driven by the matrix-localized, Hsp70-based motor. The scaffold Tim44, interacting with the matrix face of the translocon, recruits other motor subunits and binds incoming presequence. The basis of these interactions and their functional relationships remains unclear. Using site-specific in vivo crosslinking and genetic approaches in Saccharomyces cerevisiae, we found that both domains of Tim44 interact with the major matrix-exposed loop of Tim23, with the C-terminal domain (CTD) binding Tim17 as well. Results of in vitro experiments showed that the N-terminal domain (NTD) is intrinsically disordered and binds presequence near a region important for interaction with Hsp70 and Tim23. Our data suggest a model in which the CTD serves primarily to anchor Tim44 to the translocon, whereas the NTD is a dynamic arm, interacting with multiple components to drive efficient translocation. DOI: http://dx.doi.org/10.7554/eLife.23609.001 PMID:28440746

Development and testing of 11- and 24-inch hybrid motors under the joint government/industry IR&D program

NASA Technical Reports Server (NTRS)

Boardman, T. A.; Carpenter, R. L.; Goldberg, B. E.; Shaeffer, C. W.

1993-01-01

Establishment of a test facility and associated 11-in.-diameter motor for hybrid propulsion technology development at NASA's George C. Marshall Space Flight Center is discussed in this paper. Results of twenty 11-in.-diameter motor tests with a UTF-29901 (60 percent polycyclopentadiene, 40 percent hydroxyl-terminated polybutadiene)/gaseous oxygen propellant system are presented. Tests at this scale have developed fuel regression correlations for comparison with results of yet-to-be-completed, 24-in.-diameter motor tests; demonstrated combustion efficiency levels in the 95 percent range for both single- and multiple-port grain configurations; have shown smooth and stable throttling characteristics over flight-type throttle ranges; and have begun to establish criteria for stable combustion in hybrid motors. The testing of 24-in. motors has not as yet been initiated and is not addressed.

Coevolved Mutations Reveal Distinct Architectures for Two Core Proteins in the Bacterial Flagellar Motor

PubMed Central

Pandini, Alessandro; Kleinjung, Jens; Rasool, Shafqat; Khan, Shahid

2015-01-01

Switching of bacterial flagellar rotation is caused by large domain movements of the FliG protein triggered by binding of the signal protein CheY to FliM. FliG and FliM form adjacent multi-subunit arrays within the basal body C-ring. The movements alter the interaction of the FliG C-terminal (FliGC) “torque” helix with the stator complexes. Atomic models based on the Salmonella entrovar C-ring electron microscopy reconstruction have implications for switching, but lack consensus on the relative locations of the FliG armadillo (ARM) domains (amino-terminal (FliGN), middle (FliGM) and FliGC) as well as changes during chemotaxis. The generality of the Salmonella model is challenged by the variation in motor morphology and response between species. We studied coevolved residue mutations to determine the unifying elements of switch architecture. Residue interactions, measured by their coevolution, were formalized as a network, guided by structural data. Our measurements reveal a common design with dedicated switch and motor modules. The FliM middle domain (FliMM) has extensive connectivity most simply explained by conserved intra and inter-subunit contacts. In contrast, FliG has patchy, complex architecture. Conserved structural motifs form interacting nodes in the coevolution network that wire FliMM to the FliGC C-terminal, four-helix motor module (C3-6). FliG C3-6 coevolution is organized around the torque helix, differently from other ARM domains. The nodes form separated, surface-proximal patches that are targeted by deleterious mutations as in other allosteric systems. The dominant node is formed by the EHPQ motif at the FliMMFliGM contact interface and adjacent helix residues at a central location within FliGM. The node interacts with nodes in the N-terminal FliGc α-helix triad (ARM-C) and FliGN. ARM-C, separated from C3-6 by the MFVF motif, has poor intra-network connectivity consistent with its variable orientation revealed by structural data. ARM-C could be the convertor element that provides mechanistic and species diversity. PMID:26561852

Transplantation of motoneurons derived from MASH1-transfected mouse ES cells reconstitutes neural networks and improves motor function in hemiplegic mice.

PubMed

Ikeda, Ritsuko; Kurokawa, Manae S; Chiba, Shunmei; Yoshikawa, Hideshi; Hashimoto, Takuo; Tadokoro, Mamoru; Suzuki, Noboru

2004-10-01

Mouse embryonic stem (ES) cells were transfected with a MASH1 expression vector and G418-resistant cells were selected. The MASH1-transfected cells became neuron-like appearance and expressed betaIIItubulin and panNCAM. Glial fibrillary acidic protein (GFAP) and galactocerebroside (GalC)-expressing cells were rarely detected. Half of the neural cells differentiated into the Islet1+ motoneuron lineage. Thus, we obtained motoneuron lineage-enriched neuronal cells by transfection of ES cells with MASH1. A hemiplegic model of mice was developed by cryogenic injury of the motor cortex, and motoneuron lineage-enriched neuronal cells were transplanted underneath the injured motor cortex neighboring the periventricular region. The motor function of the recipients was assessed by a beam walking and rotarod tests, whereby the results gradually improved, but little improvement was observed in vehicle injected control mice. We found that the grafted cells not only remained close to the implantation site, but also exhibited substantial migration, penetrating into the damaged lesion in a directed manner up to the cortical region. Grafted neuronal cells that had migrated into the cortex were elongated axon-positive for neurofilament middle chain (NFM). Synaptophysin immunostaining showed a positive staining pattern around the graft, suggesting that the transplanted neurons interacted with the recipient neurons to form a neural network. Our study suggests that the motoneuron lineage can be induced from ES cells, and grafted cells adapt to the host environment and can reconstitute a neural network to improve motor function of a paralyzed limb.

Progesterone neuroprotection in the Wobbler mouse, a genetic model of spinal cord motor neuron disease.

PubMed

Gonzalez Deniselle, María Claudia; López-Costa, Juan José; Saavedra, Jorge Pecci; Pietranera, Luciana; Gonzalez, Susana L; Garay, Laura; Guennoun, Rachida; Schumacher, Michael; De Nicola, Alejandro F

2002-12-01

Motor neuron degeneration characterizes the spinal cord of patients with amyotrophic lateral sclerosis and the Wobbler mouse mutant. Considering that progesterone (PROG) provides neuroprotection in experimental ischemia and injury, its potential role in neurodegeneration was studied in the murine model. Two-month-old symptomatic Wobbler mice were left untreated or received sc a 20-mg PROG implant for 15 days. Both light and electron microscopy of Wobbler mice spinal cord showed severely affected motor neurons with profuse cytoplasmic vacuolation of the endoplasmic reticulum and/or Golgi apparatus and ruptured mitochondria with damaged cristae, a profile indicative of a type II cytoplasmic form of cell death. In contrast to untreated mice, neuropathology was less severe in Wobbler mice receiving PROG; including a reduction of vacuolation and of the number of vacuolated cells and better conservation of the mitochondrial ultrastructure. In biochemical studies, we determined the mRNA for the alpha3 subunit of Na,K-ATPase, a neuronal enzyme controlling ion fluxes, neurotransmission, membrane potential, and nutrient uptake. In untreated Wobbler mice, mRNA levels in motor neurons were reduced by half compared to controls, whereas PROG treatment of Wobbler mice restored the expression of alpha3 subunit Na,K-ATPase mRNA. Therefore, PROG was able to rescue motor neurons from degeneration, based on recovery of histopathological abnormalities and of mRNA levels of the sodium pump. However, because the gene mutation in Wobbler mice is still unknown, further studies are needed to unveil the action of PROG and the mechanism of neuronal death in this genetic model of neurodegeneration.

Different domains of the murine RNA polymerase I-specific termination factor mTTF-I serve distinct functions in transcription termination.

PubMed

Evers, R; Smid, A; Rudloff, U; Lottspeich, F; Grummt, I

1995-03-15

Termination of mouse ribosomal gene transcription by RNA polymerase I (Pol I) requires the specific interaction of a DNA binding protein, mTTF-I, with an 18 bp sequence element located downstream of the rRNA coding region. Here we describe the molecular cloning and functional characterization of the cDNA encoding this transcription termination factor. Recombinant mTTF-I binds specifically to the murine terminator elements and terminates Pol I transcription in a reconstituted in vitro system. Deletion analysis has defined a modular structure of mTTF-I comprising a dispensable N-terminal half, a large C-terminal DNA binding region and an internal domain which is required for transcription termination. Significantly, the C-terminal region of mTTF-I reveals striking homology to the DNA binding domains of the proto-oncogene c-Myb and the yeast transcription factor Reb1p. Site-directed mutagenesis of one of the tryptophan residues that is conserved in the homology region of c-Myb, Reb1p and mTTF-I abolishes specific DNA binding, a finding which underscores the functional relevance of these residues in DNA-protein interactions.

Different domains of the murine RNA polymerase I-specific termination factor mTTF-I serve distinct functions in transcription termination.

PubMed Central

Evers, R; Smid, A; Rudloff, U; Lottspeich, F; Grummt, I

1995-01-01

Termination of mouse ribosomal gene transcription by RNA polymerase I (Pol I) requires the specific interaction of a DNA binding protein, mTTF-I, with an 18 bp sequence element located downstream of the rRNA coding region. Here we describe the molecular cloning and functional characterization of the cDNA encoding this transcription termination factor. Recombinant mTTF-I binds specifically to the murine terminator elements and terminates Pol I transcription in a reconstituted in vitro system. Deletion analysis has defined a modular structure of mTTF-I comprising a dispensable N-terminal half, a large C-terminal DNA binding region and an internal domain which is required for transcription termination. Significantly, the C-terminal region of mTTF-I reveals striking homology to the DNA binding domains of the proto-oncogene c-Myb and the yeast transcription factor Reb1p. Site-directed mutagenesis of one of the tryptophan residues that is conserved in the homology region of c-Myb, Reb1p and mTTF-I abolishes specific DNA binding, a finding which underscores the functional relevance of these residues in DNA-protein interactions. Images PMID:7720715

Endogenous peptide profile for elucidating biosynthetic processing of the ghrelin precursor.

PubMed

Tsuchiya, Takashi; Iwakura, Hiroshi; Minamino, Naoto; Kangawa, Kenji; Sasaki, Kazuki

2017-09-02

Ghrelin is an orexigenic peptide primarily produced by gastric endocrine cells. The biosynthetic cleavage site of ghrelin has been well documented, but how its downstream region undergoes proteolytic processing remains poorly explored. Here, we provide the first snapshot of endogenous peptides from the ghrelin precursor by profiling the secretopeptidome of cultured mouse ghrelin-producing cells during exocytosis. Mapping of MS/MS sequenced peptides to the precursor highlighted three atypical monobasic processing sites, including the established C-terminus of ghrelin and the N-terminal cleavage site for obestatin, a putative 23-amino-acid C-terminally amidated peptide. However, we found that mouse obestatin does not occur in the form originally reported, but that a different amidation site is used to generate a shorter peptide. These data can be extended to study and characterize the precursor-derived peptides located downstream of ghrelin in different biological contexts. Copyright © 2017 Elsevier Inc. All rights reserved.

Structure of the mouse galectin-4 N-terminal carbohydrate-recognition domain reveals the mechanism of oligosaccharide recognition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krejciríková, Veronika; Pachl, Petr; Fábry, Milan

2011-11-18

Galectin-4, a member of the tandem-repeat subfamily of galectins, participates in cell-membrane interactions and plays an important role in cell adhesion and modulation of immunity and malignity. The oligosaccharide specificity of the mouse galectin-4 carbohydrate-recognition domains (CRDs) has been reported previously. In this work, the structure and binding properties of the N-terminal domain CRD1 were further investigated and the crystal structure of CRD1 in complex with lactose was determined at 2.1 {angstrom} resolution. The lactose-binding affinity was characterized by fluorescence measurements and two lactose-binding sites were identified: a high-affinity site with a K{sub d} value in the micromolar range (K{submore » d1} = 600 {+-} 70 {mu}M) and a low-affinity site with K{sub d2} = 28 {+-} 10 mM.« less

Olivocochlear neuron central anatomy is normal in alpha 9 knockout mice.

PubMed

Brown, M Christian; Vetter, Douglas E

2009-03-01

Olivocochlear (OC) neurons were studied in a transgenic mouse with deletion of the alpha 9 nicotinic acetylcholine receptor subunit. In this alpha 9 knockout mouse, the peripheral effects of OC stimulation are lacking and the peripheral terminals of OC neurons under outer hair cells have abnormal morphology. To account for this mouse's apparently normal hearing, it has been proposed to have central compensation via collateral branches to the cochlear nucleus. We tested this idea by staining OC neurons for acetylcholinesterase and examining their morphology in knockout mice, wild-type mice of the same background strain, and CBA/CaJ mice. Knockout mice had normal OC systems in terms of numbers of OC neurons, dendritic patterns, and numbers of branches to the cochlear nucleus. The branch terminations were mainly to edge regions and to a lesser extent the core of the cochlear nucleus, and were similar among the strains in terms of the distribution and staining density. These data demonstrate that there are no obvious changes in the central morphology of the OC neurons in alpha 9 knockout mice and make less attractive the idea that there is central compensation for deletion of the peripheral receptor in these mice.

Absence of Prenatal Forebrain Defects in the Dp(16)1Yey/+ Mouse Model of Down Syndrome

PubMed Central

Goodliffe, Joseph W.; Olmos-Serrano, Jose Luis; Aziz, Nadine M.; Pennings, Jeroen L.A.; Guedj, Faycal; Bianchi, Diana W.

2016-01-01

Studies in humans with Down syndrome (DS) show that alterations in fetal brain development are followed by postnatal deficits in neuronal numbers, synaptic plasticity, and cognitive and motor function. This same progression is replicated in several mouse models of DS. Dp(16)1Yey/+ (hereafter called Dp16) is a recently developed mouse model of DS in which the entire region of mouse chromosome 16 that is homologous to human chromosome 21 has been triplicated. As such, Dp16 mice may more closely reproduce neurodevelopmental changes occurring in humans with DS. Here, we present the first comprehensive cellular and behavioral study of the Dp16 forebrain from embryonic to adult stages. Unexpectedly, our results demonstrate that Dp16 mice do not have prenatal brain defects previously reported in human fetal neocortex and in the developing forebrains of other mouse models, including microcephaly, reduced neurogenesis, and abnormal cell proliferation. Nevertheless, we found impairments in postnatal developmental milestones, fewer inhibitory forebrain neurons, and deficits in motor and cognitive performance in Dp16 mice. Therefore, although this new model does not express prenatal morphological phenotypes associated with DS, abnormalities in the postnatal period appear sufficient to produce significant cognitive deficits in Dp16. SIGNIFICANCE STATEMENT Down syndrome (DS) leads to intellectual disability. Several mouse models have increased our understanding of the neuropathology of DS and are currently being used to test therapeutic strategies. A new mouse model that contains an expanded number of DS-related genes, known as Dp(16)1Yey/+ (Dp16), has been generated recently. We sought to determine whether the extended triplication creates a better phenocopy of DS-related brain pathologies. We measured embryonic development, forebrain maturation, and perinatal/adult behavior and revealed an absence of prenatal phenotypes in Dp16 fetal brain, but specific cellular and behavioral deficits after the first 2 postnatal weeks. These results uncover important differences in prenatal phenotype between Dp16 animals and humans with DS and other DS mouse models. PMID:26961948

The Overexpression of TDP-43 Protein in the Neuron and Oligodendrocyte Cells Causes the Progressive Motor Neuron Degeneration in the SOD1 G93A Transgenic Mouse Model of Amyotrophic Lateral Sclerosis.

PubMed

Lu, Yi; Tang, Chunyan; Zhu, Lei; Li, Jiao; Liang, Huiting; Zhang, Jie; Xu, Renshi

2016-01-01

The recent investigation suggested that the TDP-43 protein was closely related to the motor neuron degeneration in amyotrophic lateral sclerosis (ALS), but the pathogenesis contributed to motor neuron degeneration largely remained unknown. Therefore, we detected the alteration of TDP-43 expression and distribution in the adult spinal cord of the SOD1 G93A transgenic mouse model for searching the possible pathogenesis of ALS. We examined the TDP-43 expression and distribution in the different anatomic regions, segments and neural cells in the adult spinal cord at the different stages of the SOD1 wild-type and G93A transgenic model by the fluorescent immunohistochemical technology. We revealed that the amount of TDP-43 positive cell was cervical>lumbar>thoracic segment, that in the ventral horn was more than that in the dorsal horn, a few of TDP-43 protein sparsely expressed and distributed in the other regions, the TDP-43 protein weren't detected in the white matter and the central canal. The TDP-43 protein was mostly expressed and distributed in the nuclear of neuron cells and the cytoplasm of oligodendrocyte cells of the gray matter surrounding the central canal of spinal cord by the granular shape in the SOD1 wild-type and G93A transgenic mice. The amount of TDP-43 positive cell significantly increased at the onset and progression stages of ALS following with the increase of neuron death in spinal cord, particularly in the ventral horn of cervical segment at the progression stage. Our results suggested that the overexpression of TDP-43 protein in the neuron and oligodendrocyte cell causes the progressive motor neuron degeneration in the ALS-like mouse model.

ALS-associated mutant FUS induces selective motor neuron degeneration through toxic gain of function

PubMed Central

Sharma, Aarti; Lyashchenko, Alexander K.; Lu, Lei; Nasrabady, Sara Ebrahimi; Elmaleh, Margot; Mendelsohn, Monica; Nemes, Adriana; Tapia, Juan Carlos; Mentis, George Z.; Shneider, Neil A.

2016-01-01

Mutations in FUS cause amyotrophic lateral sclerosis (ALS), including some of the most aggressive, juvenile-onset forms of the disease. FUS loss-of-function and toxic gain-of-function mechanisms have been proposed to explain how mutant FUS leads to motor neuron degeneration, but neither has been firmly established in the pathogenesis of ALS. Here we characterize a series of transgenic FUS mouse lines that manifest progressive, mutant-dependent motor neuron degeneration preceded by early, structural and functional abnormalities at the neuromuscular junction. A novel, conditional FUS knockout mutant reveals that postnatal elimination of FUS has no effect on motor neuron survival or function. Moreover, endogenous FUS does not contribute to the onset of the ALS phenotype induced by mutant FUS. These findings demonstrate that FUS-dependent motor degeneration is not due to loss of FUS function, but to the gain of toxic properties conferred by ALS mutations. PMID:26842965

ALS-associated mutant FUS induces selective motor neuron degeneration through toxic gain of function.

PubMed

Sharma, Aarti; Lyashchenko, Alexander K; Lu, Lei; Nasrabady, Sara Ebrahimi; Elmaleh, Margot; Mendelsohn, Monica; Nemes, Adriana; Tapia, Juan Carlos; Mentis, George Z; Shneider, Neil A

2016-02-04

Mutations in FUS cause amyotrophic lateral sclerosis (ALS), including some of the most aggressive, juvenile-onset forms of the disease. FUS loss-of-function and toxic gain-of-function mechanisms have been proposed to explain how mutant FUS leads to motor neuron degeneration, but neither has been firmly established in the pathogenesis of ALS. Here we characterize a series of transgenic FUS mouse lines that manifest progressive, mutant-dependent motor neuron degeneration preceded by early, structural and functional abnormalities at the neuromuscular junction. A novel, conditional FUS knockout mutant reveals that postnatal elimination of FUS has no effect on motor neuron survival or function. Moreover, endogenous FUS does not contribute to the onset of the ALS phenotype induced by mutant FUS. These findings demonstrate that FUS-dependent motor degeneration is not due to loss of FUS function, but to the gain of toxic properties conferred by ALS mutations.

Correlations of Behavioral Deficits with Brain Pathology Assessed through Longitudinal MRI and Histopathology in the HdhQ150/Q150 Mouse Model of Huntington’s Disease

PubMed Central

Rattray, Ivan; Smith, Edward J.; Crum, William R.; Walker, Thomas A.; Gale, Richard; Bates, Gillian P.

2017-01-01

A variety of mouse models have been developed that express mutant huntingtin (mHTT) leading to aggregates and inclusions that model the molecular pathology observed in Huntington’s disease. Here we show that although homozygous HdhQ150 knock-in mice developed motor impairments (rotarod, locomotor activity, grip strength) by 36 weeks of age, cognitive dysfunction (swimming T maze, fear conditioning, odor discrimination, social interaction) was not evident by 94 weeks. Concomitant to behavioral assessments, T2-weighted MRI volume measurements indicated a slower striatal growth with a significant difference between wild type (WT) and HdhQ150 mice being present even at 15 weeks. Indeed, MRI indicated significant volumetric changes prior to the emergence of the “clinical horizon” of motor impairments at 36 weeks of age. A striatal decrease of 27% was observed over 94 weeks with cortex (12%) and hippocampus (21%) also indicating significant atrophy. A hypothesis-free analysis using tensor-based morphometry highlighted further regions undergoing atrophy by contrasting brain growth and regional neurodegeneration. Histology revealed the widespread presence of mHTT aggregates and cellular inclusions. However, there was little evidence of correlations between these outcome measures, potentially indicating that other factors are important in the causal cascade linking the molecular pathology to the emergence of behavioral impairments. In conclusion, the HdhQ150 mouse model replicates many aspects of the human condition, including an extended pre-manifest period prior to the emergence of motor impairments. PMID:28099507

Transcriptional profiles of supragranular-enriched genes associate with corticocortical network architecture in the human brain

PubMed Central

Krienen, Fenna M.; Yeo, B. T. Thomas; Ge, Tian; Buckner, Randy L.; Sherwood, Chet C.

2016-01-01

The human brain is patterned with disproportionately large, distributed cerebral networks that connect multiple association zones in the frontal, temporal, and parietal lobes. The expansion of the cortical surface, along with the emergence of long-range connectivity networks, may be reflected in changes to the underlying molecular architecture. Using the Allen Institute’s human brain transcriptional atlas, we demonstrate that genes particularly enriched in supragranular layers of the human cerebral cortex relative to mouse distinguish major cortical classes. The topography of transcriptional expression reflects large-scale brain network organization consistent with estimates from functional connectivity MRI and anatomical tracing in nonhuman primates. Microarray expression data for genes preferentially expressed in human upper layers (II/III), but enriched only in lower layers (V/VI) of mouse, were cross-correlated to identify molecular profiles across the cerebral cortex of postmortem human brains (n = 6). Unimodal sensory and motor zones have similar molecular profiles, despite being distributed across the cortical mantle. Sensory/motor profiles were anticorrelated with paralimbic and certain distributed association network profiles. Tests of alternative gene sets did not consistently distinguish sensory and motor regions from paralimbic and association regions: (i) genes enriched in supragranular layers in both humans and mice, (ii) genes cortically enriched in humans relative to nonhuman primates, (iii) genes related to connectivity in rodents, (iv) genes associated with human and mouse connectivity, and (v) 1,454 gene sets curated from known gene ontologies. Molecular innovations of upper cortical layers may be an important component in the evolution of long-range corticocortical projections. PMID:26739559

Deuterium-reinforced linoleic acid lowers lipid peroxidation and mitigates cognitive impairment in the Q140 knock in mouse model of Huntington's disease.

PubMed

Hatami, Asa; Zhu, Chunni; Relaño-Gines, Aroa; Elias, Chris; Galstyan, Arpine; Jun, Michael; Milne, Ginger; Cantor, Charles R; Chesselet, Marie-Francoise; Shchepinov, Mikhail S

2018-06-22

Huntington's disease (HD) is an autosomal dominant neurodegenerative disease which has no effective treatment and is characterized by psychiatric disorders, motor alterations, and dementia, with the cognitive deficits representing a devastating aspect of the disorder. Oxidative stress and elevated levels of lipid peroxidation (LPO) products are found in mouse models and patients with HD, suggesting that strategies to reduce LPO may be beneficial in HD. In contrast to traditional antioxidants, substituting hydrogen with deuterium at bis-allylic sites in polyunsaturated fatty acids (D-PUFA) decreases the rate-limiting initiation step of PUFA autoxidation, a strategy that has shown benefits in other neurodegenerative diseases. Here we investigated the effect of D-PUFA treatment in a knock-in mouse model of HD (Q140) which presents motor deficits and neuropathology from a few months of age, and progressive cognitive decline. Q140 knock-in mice were fed a diet containing either D- or H-PUFAs for 5 months starting at one month of age. D-PUFA treatment significantly decreased F 2 -isoprostanes in the striatum by approximately 80% as compared to H-PUFA treatment and improved performance in novel object recognition tests, without significantly changing motor deficits or huntingtin aggregation. Therefore, D-PUFA administration represents a promising new strategy to broadly reduce rates of LPO, and may be useful in improving a subset of the core deficits in HD. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Mitochondrial Dysfunction and Decrease in Body Weight of a Transgenic Knock-in Mouse Model for TDP-43*

PubMed Central

Stribl, Carola; Samara, Aladin; Trümbach, Dietrich; Peis, Regina; Neumann, Manuela; Fuchs, Helmut; Gailus-Durner, Valerie; Hrabě de Angelis, Martin; Rathkolb, Birgit; Wolf, Eckhard; Beckers, Johannes; Horsch, Marion; Neff, Frauke; Kremmer, Elisabeth; Koob, Sebastian; Reichert, Andreas S.; Hans, Wolfgang; Rozman, Jan; Klingenspor, Martin; Aichler, Michaela; Walch, Axel Karl; Becker, Lore; Klopstock, Thomas; Glasl, Lisa; Hölter, Sabine M.; Wurst, Wolfgang; Floss, Thomas

2014-01-01

The majority of amyotrophic lateral sclerosis (ALS) cases as well as many patients suffering from frontotemporal lobar dementia (FTLD) with ubiquitinated inclusion bodies show TDP-43 pathology, the protein encoded by the TAR DNA-binding protein (Tardbp) gene. We used recombinase-mediated cassette exchange to introduce an ALS patient cDNA into the mouse Tdp-43 locus. Expression levels of human A315T TDP-43 protein were 300% elevated in heterozygotes, whereas the endogenous mouse Tdp-43 was decreased to 20% of wild type levels as a result of disturbed feedback regulation. Heterozygous TDP-43A315TKi mutants lost 10% of their body weight and developed insoluble TDP-43 protein starting as early as 3 months after birth, a pathology that was exacerbated with age. We analyzed the splicing patterns of known Tdp-43 target genes as well as genome-wide gene expression levels in different tissues that indicated mitochondrial dysfunction. In heterozygous mutant animals, we observed a relative decrease in expression of Parkin (Park2) and the fatty acid transporter CD36 along with an increase in fatty acids, HDL cholesterol, and glucose in the blood. As seen in transmission electron microscopy, neuronal cells in motor cortices of TDP-43A315TKi animals had abnormal neuronal mitochondrial cristae formation. Motor neurons were reduced to 90%, but only slight motoric impairment was detected. The observed phenotype was interpreted as a predisease model, which might be valuable for the identification of further environmental or genetic triggers of neurodegeneration. PMID:24515116

Transcriptional profiles of supragranular-enriched genes associate with corticocortical network architecture in the human brain.

PubMed

Krienen, Fenna M; Yeo, B T Thomas; Ge, Tian; Buckner, Randy L; Sherwood, Chet C

2016-01-26

The human brain is patterned with disproportionately large, distributed cerebral networks that connect multiple association zones in the frontal, temporal, and parietal lobes. The expansion of the cortical surface, along with the emergence of long-range connectivity networks, may be reflected in changes to the underlying molecular architecture. Using the Allen Institute's human brain transcriptional atlas, we demonstrate that genes particularly enriched in supragranular layers of the human cerebral cortex relative to mouse distinguish major cortical classes. The topography of transcriptional expression reflects large-scale brain network organization consistent with estimates from functional connectivity MRI and anatomical tracing in nonhuman primates. Microarray expression data for genes preferentially expressed in human upper layers (II/III), but enriched only in lower layers (V/VI) of mouse, were cross-correlated to identify molecular profiles across the cerebral cortex of postmortem human brains (n = 6). Unimodal sensory and motor zones have similar molecular profiles, despite being distributed across the cortical mantle. Sensory/motor profiles were anticorrelated with paralimbic and certain distributed association network profiles. Tests of alternative gene sets did not consistently distinguish sensory and motor regions from paralimbic and association regions: (i) genes enriched in supragranular layers in both humans and mice, (ii) genes cortically enriched in humans relative to nonhuman primates, (iii) genes related to connectivity in rodents, (iv) genes associated with human and mouse connectivity, and (v) 1,454 gene sets curated from known gene ontologies. Molecular innovations of upper cortical layers may be an important component in the evolution of long-range corticocortical projections.

Modulation of [3H]DAGO binding by substance P (SP) and SP fragments in the mouse brain and spinal cord via MU1 interactions.

PubMed

Krumins, S A; Kim, D C; Seybold, V S; Larson, A A

1989-01-01

Binding of [3H]DAGO to fresh, frozen or beta-funaltrexamine (beta-FNA) pretreated membranes of mouse brain and spinal cord was extensively studied using substance P (SP) or SP fragments as potential competitors and/or modulators. The objective was to determine whether SP exerts its analgesic effect by interacting with mu opioid receptors. The affinity of DAGO was reduced and binding capacity was increased in the presence of SP or the N-terminal SP fragments SP(1-9) and SP(1-4) but not the C-terminal SP fragment SP(5-11). Because sub-nanomolar concentrations of SP or N-terminal SP fragments displaced [3H] DAGO binding to a minor but detectable degree, it is suggested that SP interacts with mu 1 sites through its N-terminus portion. The effect of SP on DAGO binding was less in the spinal cord compared to the rest of the brain. Modulation of DAGO binding by SP was enhanced in the brain after pretreatment of membranes with the narcotic antagonist beta-FNA. These results suggest a novel mechanism for the analgesic action of SP.

Hepatocyte nuclear factor 4alpha contributes to thyroid hormone homeostasis by cooperatively regulating the type 1 iodothyronine deiodinase gene with GATA4 and Kruppel-like transcription factor 9.

PubMed

Ohguchi, Hiroto; Tanaka, Toshiya; Uchida, Aoi; Magoori, Kenta; Kudo, Hiromi; Kim, Insook; Daigo, Kenji; Sakakibara, Iori; Okamura, Masashi; Harigae, Hideo; Sasaki, Takeshi; Osborne, Timothy F; Gonzalez, Frank J; Hamakubo, Takao; Kodama, Tatsuhiko; Sakai, Juro

2008-06-01

Type 1 iodothyronine deiodinase (Dio1), a selenoenzyme catalyzing the bioactivation of thyroid hormone, is highly expressed in the liver. Dio1 mRNA and enzyme activity levels are markedly reduced in the livers of hepatocyte nuclear factor 4alpha (HNF4alpha)-null mice, thus accounting for its liver-specific expression. Consistent with this deficiency, serum T4 and rT3 concentrations are elevated in these mice compared with those in HNF4alpha-floxed control littermates; however, serum T3 levels are unchanged. Promoter analysis of the mouse Dio1 gene demonstrated that HNF4alpha plays a key role in the transactivation of the mouse Dio1 gene. Deletion and substitution mutation analyses demonstrated that a proximal HNF4alpha site (direct repeat 1 [TGGACAAAGGTGC]; HNF4alpha-RE) is crucial for transactivation of the mouse Dio1 gene by HNF4alpha. Mouse Dio1 is also stimulated by thyroid hormone signaling, but a direct role for thyroid hormone receptor action has not been reported. We also showed that thyroid hormone-inducible Krüppel-like factor 9 (KLF9) stimulates the mouse Dio1 promoter very efficiently through two CACCC sequences that are located on either side of HNF4alpha-RE. Furthermore, KLF9 functions together with HNF4alpha and GATA4 to synergistically activate the mouse Dio1 promoter, suggesting that Dio1 is regulated by thyroid hormone in the mouse through an indirect mechanism requiring prior KLF9 induction. In addition, we showed that physical interactions between the C-terminal zinc finger domain (Cf) of GATA4 and activation function 2 of HNF4alpha and between the basic domain adjacent to Cf of GATA4 and a C-terminal domain of KLF9 are both required for this synergistic response. Taken together, these results suggest that HNF4alpha regulates thyroid hormone homeostasis through transcriptional regulation of the mouse Dio1 gene with GATA4 and KLF9.

Hepatocyte Nuclear Factor 4α Contributes to Thyroid Hormone Homeostasis by Cooperatively Regulating the Type 1 Iodothyronine Deiodinase Gene with GATA4 and Krüppel-Like Transcription Factor 9▿ †

PubMed Central

Ohguchi, Hiroto; Tanaka, Toshiya; Uchida, Aoi; Magoori, Kenta; Kudo, Hiromi; Kim, Insook; Daigo, Kenji; Sakakibara, Iori; Okamura, Masashi; Harigae, Hideo; Sasaki, Takeshi; Osborne, Timothy F.; Gonzalez, Frank J.; Hamakubo, Takao; Kodama, Tatsuhiko; Sakai, Juro

2008-01-01

Type 1 iodothyronine deiodinase (Dio1), a selenoenzyme catalyzing the bioactivation of thyroid hormone, is highly expressed in the liver. Dio1 mRNA and enzyme activity levels are markedly reduced in the livers of hepatocyte nuclear factor 4α (HNF4α)-null mice, thus accounting for its liver-specific expression. Consistent with this deficiency, serum T4 and rT3 concentrations are elevated in these mice compared with those in HNF4α-floxed control littermates; however, serum T3 levels are unchanged. Promoter analysis of the mouse Dio1 gene demonstrated that HNF4α plays a key role in the transactivation of the mouse Dio1 gene. Deletion and substitution mutation analyses demonstrated that a proximal HNF4α site (direct repeat 1 [TGGACAAAGGTGC]; HNF4α-RE) is crucial for transactivation of the mouse Dio1 gene by HNF4α. Mouse Dio1 is also stimulated by thyroid hormone signaling, but a direct role for thyroid hormone receptor action has not been reported. We also showed that thyroid hormone-inducible Krüppel-like factor 9 (KLF9) stimulates the mouse Dio1 promoter very efficiently through two CACCC sequences that are located on either side of HNF4α-RE. Furthermore, KLF9 functions together with HNF4α and GATA4 to synergistically activate the mouse Dio1 promoter, suggesting that Dio1 is regulated by thyroid hormone in the mouse through an indirect mechanism requiring prior KLF9 induction. In addition, we showed that physical interactions between the C-terminal zinc finger domain (Cf) of GATA4 and activation function 2 of HNF4α and between the basic domain adjacent to Cf of GATA4 and a C-terminal domain of KLF9 are both required for this synergistic response. Taken together, these results suggest that HNF4α regulates thyroid hormone homeostasis through transcriptional regulation of the mouse Dio1 gene with GATA4 and KLF9. PMID:18426912

Dynamic interactions between the promoter and terminator regions of the mammalian BRCA1 gene.

PubMed

Tan-Wong, Sue Mei; French, Juliet D; Proudfoot, Nicholas J; Brown, Melissa A

2008-04-01

The 85-kb breast cancer-associated gene BRCA1 is an established tumor suppressor gene, but its regulation is poorly understood. We demonstrate by gene conformation analysis in both human cell lines and mouse mammary tissue that gene loops are imposed on BRCA1 between the promoter, introns, and terminator region. Significantly, association between the BRCA1 promoter and terminator regions change upon estrogen stimulation and during lactational development. Loop formation is transcription-dependent, suggesting that transcriptional elongation plays an active role in BRCA1 loop formation. We show that the BRCA1 terminator region can suppress estrogen-induced transcription and so may regulate BRCA1 expression. Significantly, BRCA1 promoter and terminator interactions vary in different breast cancer cell lines, indicating that defects in BRCA1 chromatin structure may contribute to dysregulated expression of BRCA1 seen in breast tumors.

Cyclic di-GMP differentially tunes a bacterial flagellar motor through a novel class of CheY-like regulators.

PubMed

Nesper, Jutta; Hug, Isabelle; Kato, Setsu; Hee, Chee-Seng; Habazettl, Judith Maria; Manfredi, Pablo; Grzesiek, Stephan; Schirmer, Tilman; Emonet, Thierry; Jenal, Urs

2017-11-01

The flagellar motor is a sophisticated rotary machine facilitating locomotion and signal transduction. Owing to its important role in bacterial behavior, its assembly and activity are tightly regulated. For example, chemotaxis relies on a sensory pathway coupling chemical information to rotational bias of the motor through phosphorylation of the motor switch protein CheY. Using a chemical proteomics approach, we identified a novel family of CheY-like (Cle) proteins in Caulobacter crescentus , which tune flagellar activity in response to binding of the second messenger c-di-GMP to a C-terminal extension. In their c-di-GMP bound conformation Cle proteins interact with the flagellar switch to control motor activity. We show that individual Cle proteins have adopted discrete cellular functions by interfering with chemotaxis and by promoting rapid surface attachment of motile cells. This study broadens the regulatory versatility of bacterial motors and unfolds mechanisms that tie motor activity to mechanical cues and bacterial surface adaptation.

Motor-circuit communication matrix from spinal cord to brainstem neurons revealed by developmental origin.

PubMed

Pivetta, Chiara; Esposito, Maria Soledad; Sigrist, Markus; Arber, Silvia

2014-01-30

Accurate motor-task execution relies on continuous comparison of planned and performed actions. Motor-output pathways establish internal circuit collaterals for this purpose. Here we focus on motor collateral organization between spinal cord and upstream neurons in the brainstem. We used a newly developed mouse genetic tool intersectionally with viruses to uncover the connectivity rules of these ascending pathways by capturing the transient expression of neuronal subpopulation determinants. We reveal a widespread and diverse network of spinal dual-axon neurons, with coincident input to forelimb motor neurons and the lateral reticular nucleus (LRN) in the brainstem. Spinal information to the LRN is not segregated by motor pool or neurotransmitter identity. Instead, it is organized according to the developmental domain origin of the progenitor cells. Thus, excerpts of most spinal information destined for action are relayed to supraspinal centers through exquisitely organized ascending connectivity modules, enabling precise communication between command and execution centers of movement. Copyright © 2014 Elsevier Inc. All rights reserved.

Direct identification of the site of binding on the chaperone SecB for the amino terminus of the translocon motor SecA.

PubMed

Randall, Linda L; Henzl, Michael T

2010-06-01

Protein export mediated by the general secretory Sec system in Escherichia coli proceeds by a dynamic transfer of a precursor polypeptide from the chaperone SecB to the SecA ATPase motor of the translocon and subsequently into and through the channel of the membrane-embedded SecYEG heterotrimer. The complex between SecA and SecB is stabilized by several separate sites of contact. Here we have demonstrated directly an interaction between the N-terminal residues 2 through 11 of SecA and the C-terminal 13 residues of SecB by isothermal titration calorimetry and analytical sedimentation velocity centrifugation. We discuss the unusual binding properties of SecA and SecB in context of a model for transfer of the precursor along the pathway of export.

The Drosophila Microtubule-Associated Protein Mars Stabilizes Mitotic Spindles by Crosslinking Microtubules through Its N-Terminal Region

PubMed Central

Zhang, Gang; Beati, Hamze; Nilsson, Jakob; Wodarz, Andreas

2013-01-01

Correct segregation of genetic material relies on proper assembly and maintenance of the mitotic spindle. How the highly dynamic microtubules (MTs) are maintained in stable mitotic spindles is a key question to be answered. Motor and non-motor microtubule associated proteins (MAPs) have been reported to stabilize the dynamic spindle through crosslinking adjacent MTs. Mars, a novel MAP, is essential for the early development of Drosophila embryos. Previous studies showed that Mars is required for maintaining an intact mitotic spindle but did not provide a molecular mechanism for this function. Here we show that Mars is able to stabilize the mitotic spindle in vivo. Both in vivo and in vitro data reveal that the N-terminal region of Mars functions in the stabilization of the mitotic spindle by crosslinking adjacent MTs. PMID:23593258

Failures of Perception in the Low-Prevalence Effect: Evidence From Active and Passive Visual Search

PubMed Central

Hout, Michael C.; Walenchok, Stephen C.; Goldinger, Stephen D.; Wolfe, Jeremy M.

2017-01-01

In visual search, rare targets are missed disproportionately often. This low-prevalence effect (LPE) is a robust problem with demonstrable societal consequences. What is the source of the LPE? Is it a perceptual bias against rare targets or a later process, such as premature search termination or motor response errors? In 4 experiments, we examined the LPE using standard visual search (with eye tracking) and 2 variants of rapid serial visual presentation (RSVP) in which observers made present/absent decisions after sequences ended. In all experiments, observers looked for 2 target categories (teddy bear and butterfly) simultaneously. To minimize simple motor errors, caused by repetitive absent responses, we held overall target prevalence at 50%, with 1 low-prevalence and 1 high-prevalence target type. Across conditions, observers either searched for targets among other real-world objects or searched for specific bears or butterflies among within-category distractors. We report 4 main results: (a) In standard search, high-prevalence targets were found more quickly and accurately than low-prevalence targets. (b) The LPE persisted in RSVP search, even though observers never terminated search on their own. (c) Eye-tracking analyses showed that high-prevalence targets elicited better attentional guidance and faster perceptual decisions. And (d) even when observers looked directly at low-prevalence targets, they often (12%–34% of trials) failed to detect them. These results strongly argue that low-prevalence misses represent failures of perception when early search termination or motor errors are controlled. PMID:25915073

Distribution and ultrastructure of dopaminergic neurons in the dorsal motor nucleus of the vagus projecting to the stomach of the rat.

PubMed

Hayakawa, Tetsu; Takanaga, Akinori; Tanaka, Koichi; Maeda, Seishi; Seki, Makoto

2004-04-23

Almost all parasympathetic preganglionic motor neurons contain acetylcholine, whereas quite a few motor neurons in the dorsal motor nucleus of the vagus (DMV) contain dopamine. We determined the distribution and ultrastructure of these dopaminergic neurons with double-labeling immunohistochemistry for tyrosine hydroxylase (TH) and the retrograde tracer cholera toxin subunit b (CTb) following its injection into the stomach. A few TH-immunoreactive (TH-ir) neurons were found in the rostral half of the DMV, while a moderate number of these neurons were found in the caudal half. Most of the TH-ir neurons (78.4%) were double-labeled for CTb in the half of the DMV caudal to the area postrema, but only a few TH-ir neurons (5.5%) were double-labeled in the rostral half. About 20% of gastric motor neurons showed TH-immunoreactivity in the caudal half of the DMV, but only 0.3% were TH-ir in the rostral half. In all gastric motor neurons, 8.1% were double-labeled for TH. The ultrastructure of the TH-ir neurons in the caudal DMV was determined with immuno-gold-silver labeling. The TH-ir neurons were small (20.4 x 12.4 microm), round or oval, and contained numerous mitochondria, many free ribosomes, several Golgi apparatuses, a round nucleus and a few Nissl bodies. The average number of axosomatic terminals per section was 4.0. More than half of them contained round synaptic vesicles and made asymmetric synaptic contacts (Gray's type I). Most of the axodendritic terminals contacting TH-ir dendrites were Gray's type I (90%), but a few contained pleomorphic vesicles and made symmetric synaptic contacts (Gray's type II).

Corticobulbar projections from distinct motor cortical areas to the reticular formation in macaque monkeys.

PubMed

Fregosi, Michela; Contestabile, Alessandro; Hamadjida, Adjia; Rouiller, Eric M

2017-06-01

Corticospinal and corticobulbar descending pathways act in parallel with brainstem systems, such as the reticulospinal tract, to ensure the control of voluntary movements via direct or indirect influences onto spinal motoneurons. The aim of this study was to investigate the corticobulbar projections from distinct motor cortical areas onto different nuclei of the reticular formation. Seven adult macaque monkeys were analysed for the location of corticobulbar axonal boutons, and one monkey for reticulospinal neurons' location. The anterograde tracer BDA was injected in the premotor cortex (PM), in the primary motor cortex (M1) or in the supplementary motor area (SMA), in 3, 3 and 1 monkeys respectively. BDA anterograde labelling of corticobulbar axons were analysed on brainstem histological sections and overlapped with adjacent Nissl-stained sections for cytoarchitecture. One adult monkey was analysed for retrograde CB tracer injected in C5-C8 hemispinal cord to visualise reticulospinal neurons. The corticobulbar axons formed bilateral terminal fields with boutons terminaux and en passant, which were quantified in various nuclei belonging to the Ponto-Medullary Reticular Formation (PMRF). The corticobulbar projections from both PM and SMA tended to end mainly ipsilaterally in PMRF, but contralaterally when originating from M1. Furthermore, the corticobulbar projection was less dense when originating from M1 than from non-primary motor areas (PM, SMA). The main nuclei of bouton terminals corresponded to the regions where reticulospinal neurons were located with CB retrograde tracing. In conclusion, the corticobulbar projection differs according to the motor cortical area of origin in density and laterality. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Preprodynorphin-expressing neurons constitute a large subgroup of somatostatin-expressing GABAergic interneurons in the mouse neocortex.

PubMed

Sohn, Jaerin; Hioki, Hiroyuki; Okamoto, Shinichiro; Kaneko, Takeshi

2014-05-01

Dynorphins, leumorphin, and neoendorphins are preprodynorphin (PPD)-derived peptides and ligands for κ-opioid receptors. Using an antibody to PPD C-terminal, we investigated the chemical and molecular characteristics of PPD-expressing neurons in mouse neocortex. PPD-immunopositive neuronal somata were distributed most frequently in layer 5 and less frequently in layers 2-4 and 6 throughout neocortical regions. Combined labeling of immunofluorescence and fluorescent mRNA signals revealed that almost all PPD-immunopositive neurons expressed glutamic acid decarboxylase but not vesicular glutamate transporter, indicating their γ-aminobutyric acid (GABA)ergic characteristics, and that PPD-immunopositive neurons accounted for 15% of GABAergic interneurons in the primary somatosensory area. As GABAergic interneurons were divided into several groups by specific markers, we further examined the chemical characteristics of PPD-expressing neurons by the double immunofluorescence labeling method. More than 95% of PPD-immunopositive neurons were also somatostatin (SOM)-immunopositive in the primary somatosensory, primary motor, orbitofrontal, and primary visual areas, but only 24% were SOM-immunopositive in the medial prefrontal cortex. In the primary somatosensory area, PPD-immunopositive neurons constituted 50%, 79%, 55%, and 17% of SOM-immunopositive neurons in layers 2-3, 4, 5, and 6, respectively. Although SOM-expressing neurons contained calretinin-, neuropeptide Y-, nitric oxide synthase-, and reelin-expressing neurons as subgroups, only reelin immunoreactivity was detected in many PPD-immunopositive neurons. These results indicate that PPD-expressing neurons constitute a large subgroup of SOM-expressing cortical interneurons, and the PPD/SOM-expressing GABAergic neurons might serve not only as inhibitory elements in the local cortical circuit, but also as modulators for cortical neurons expressing κ-opioid and/or SOM receptors. Copyright © 2013 Wiley Periodicals, Inc.

Small molecule modulator of protein disulfide isomerase attenuates mutant huntingtin toxicity and inhibits endoplasmic reticulum stress in a mouse model of Huntington's disease.

PubMed

Zhou, Xiao; Li, Gang; Kaplan, Anna; Gaschler, Michael M; Zhang, Xiaoyan; Hou, Zhipeng; Jiang, Mali; Zott, Roseann; Cremers, Serge; Stockwell, Brent R; Duan, Wenzhen

2018-05-01

Huntington's disease (HD) is caused by a cytosine-adenine-guanine (CAG) trinucleotide repeat expansion in the huntingtin (HTT) gene encoding an elongated polyglutamine tract within the N-terminal of the huntingtin protein (Htt) and leads to Htt misfolding, aberrant protein aggregation, and progressive appearance of disease symptoms. Chronic activation of endoplasmic reticulum (ER) stress by mutant Htt (mHtt) results in cellular dysfunction and ultimately cell death. Protein disulfide isomerase (PDI) is a chaperone protein located in the ER. Our previous studies demonstrated that mHtt caused PDI to accumulate at mitochondria-associated ER membranes and triggered cell death, and that modulating PDI activity using small molecules protected cells again mHtt toxicity in cell and brain slice models of HD. In this study, we demonstrated that PDI is upregulated in the HD human brain, in cell and mouse models. Chronic administration of a reversible, brain penetrable small molecule PDI modulator, LOC14 (20 mg/kg/day), significantly improved motor function, attenuated brain atrophy and extended survival in the N171-82Q HD mice. Moreover, LOC14 preserved medium spiny neuronal marker dopamine- and cyclic-AMP-regulated phosphoprotein of molecular weight 32 000 (DARPP32) levels in the striatum of HD mice. Mechanistic study revealed that LOC14 suppressed mHtt-induced ER stress, indicated by repressing the abnormally upregulated ER stress proteins in HD models. These findings suggest that LOC14 is promising to be further optimized for clinical trials of HD, and modulation of signaling pathways coping with ER stress may constitute an attractive approach to reduce mHtt toxicity and identify new therapeutic targets for treatment of HD.

Selective rescue of heightened anxiety but not gait ataxia in a premutation 90CGG mouse model of Fragile X-associated tremor/ataxia syndrome.

PubMed

Castro, Hoanna; Kul, Emre; Buijsen, Ronald A M; Severijnen, Lies-Anne W F M; Willemsen, Rob; Hukema, Renate K; Stork, Oliver; Santos, Mónica

2017-06-01

A CGG-repeat expansion in the premutation range in the Fragile X mental retardation 1 gene (FMR1) has been identified as the genetic cause of Fragile X-associated tremor/ataxia syndrome (FXTAS), a late-onset neurodegenerative disorder that manifests with action tremor, gait ataxia and cognitive impairments. In this study, we used a bigenic mouse model, in which expression of a 90CGG premutation tract is activated in neural cells upon doxycycline administration-P90CGG mouse model. We, here, demonstrate the behavioural manifestation of clinically relevant features of FXTAS patients and premutation carrier individuals in this inducible mouse model. P90CGG mice display heightened anxiety, deficits in motor coordination and impaired gait and represent the first FXTAS model that exhibits an ataxia phenotype as observed in patients. The behavioural phenotype is accompanied by the formation of ubiquitin/FMRpolyglycine-positive intranuclear inclusions, as another hallmark of FXTAS, in the cerebellum, hippocampus and amygdala. Strikingly, upon cessation of transgene induction the anxiety phenotype of mice recovers along with a reduction of intranuclear inclusions in dentate gyrus and amygdala. In contrast, motor function deteriorates further and no reduction in intranuclear inclusions can be observed in the cerebellum. Our data thus demonstrate that expression of a 90CGG premutation expansion outside of the FMR1 context is sufficient to evoke an FXTAS-like behavioural phenotype. Brain region-specific neuropathology and (partial) behavioural reversibility make the inducible P90CGG a valuable mouse model for testing pathogenic mechanisms and therapeutic intervention methods. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Utility of Survival Motor Neuron ELISA for Spinal Muscular Atrophy Clinical and Preclinical Analyses

PubMed Central

Kobayashi, Dione T.; Olson, Rory J.; Sly, Laurel; Swanson, Chad J.; Chung, Brett; Naryshkin, Nikolai; Narasimhan, Jana; Bhattacharyya, Anuradha; Mullenix, Michael; Chen, Karen S.

2011-01-01

Objectives Genetic defects leading to the reduction of the survival motor neuron protein (SMN) are a causal factor for Spinal Muscular Atrophy (SMA). While there are a number of therapies under evaluation as potential treatments for SMA, there is a critical lack of a biomarker method for assessing efficacy of therapeutic interventions, particularly those targeting upregulation of SMN protein levels. Towards this end we have engaged in developing an immunoassay capable of accurately measuring SMN protein levels in blood, specifically in peripheral blood mononuclear cells (PBMCs), as a tool for validating SMN protein as a biomarker in SMA. Methods A sandwich enzyme-linked immunosorbent assay (ELISA) was developed and validated for measuring SMN protein in human PBMCs and other cell lysates. Protocols for detection and extraction of SMN from transgenic SMA mouse tissues were also developed. Results The assay sensitivity for human SMN is 50 pg/mL. Initial analysis reveals that PBMCs yield enough SMN to analyze from blood volumes of less than 1 mL, and SMA Type I patients' PBMCs show ∼90% reduction of SMN protein compared to normal adults. The ELISA can reliably quantify SMN protein in human and mouse PBMCs and muscle, as well as brain, and spinal cord from a mouse model of severe SMA. Conclusions This SMN ELISA assay enables the reliable, quantitative and rapid measurement of SMN in healthy human and SMA patient PBMCs, muscle and fibroblasts. SMN was also detected in several tissues in a mouse model of SMA, as well as in wildtype mouse tissues. This SMN ELISA has general translational applicability to both preclinical and clinical research efforts. PMID:21904622

5-HT2A receptor antagonists improve motor impairments in the MPTP mouse model of Parkinson's disease.

PubMed

Ferguson, Marcus C; Nayyar, Tultul; Deutch, Ariel Y; Ansah, Twum A

2010-01-01

Clinical observations have suggested that ritanserin, a 5-HT(2A/C) receptor antagonist may reduce motor deficits in persons with Parkinson's Disease (PD). To better understand the potential antiparkinsonian actions of ritanserin, we compared the effects of ritanserin with the selective 5-HT(2A) receptor antagonist M100907 and the selective 5-HT(2C) receptor antagonist SB 206553 on motor impairments in mice treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). MPTP-treated mice exhibited decreased performance on the beam-walking apparatus. These motor deficits were reversed by acute treatment with L-3,4-dihydroxyphenylalanine (levodopa). Both the mixed 5-HT(2A/C) antagonist ritanserin and the selective 5-HT(2A) antagonist M100907 improved motor performance on the beam-walking apparatus. In contrast, SB 206553 was ineffective in improving the motor deficits in MPTP-treated mice. These data suggest that 5-HT(2A) receptor antagonists may represent a novel approach to ameliorate motor symptoms of Parkinson's disease. Published by Elsevier Ltd.

5-HT2A receptor antagonists improve motor impairments in the MPTP mouse model of Parkinson's disease

PubMed Central

Ferguson, Marcus C.; Nayyar, Tultul; Deutch, Ariel Y.; Ansah, Twum A.

2010-01-01

Clinical observations have suggested that ritanserin, a 5-HT2A/C receptor antagonist may reduce motor deficits in persons with Parkinson's Disease (PD). To better understand the potential antiparkinsonian actions of ritanserin, we compared the effects of ritanserin with the selective 5-HT2A receptor antagonist M100907 and the selective 5-HT2C receptor antagonist SB 206553 on motor impairments in mice treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). MPTP-treated mice exhibited decreased performance on the beam-walking apparatus. These motor deficits were reversed by acute treatment with L-3,4-dihydroxyphenylalanine (levodopa). Both the mixed 5-HT2A/C antagonist ritanserin and the selective 5-HT2A antagonist M100907 improved motor performance on the beam-walking apparatus. In contrast, SB 206553 was ineffective in improving the motor deficits in MPTP-treated mice. These data suggest that 5-HT2A receptor antagonists may represent a novel approach to ameliorate motor symptoms of Parkinson's disease. PMID:20361986

Midbrain stimulation-evoked lumbar spinal activity in the adult decerebrate mouse.

PubMed

Stecina, Katinka

2017-08-15

Genetic techniques rendering murine models a popular choice for neuroscience research has led to important insights on neural networks controlling locomotor function. Using genetically altered mouse models for in vivo, electrophysiological studies in the adult state could validate key principles of locomotor network organization that have been described in neonatal, in vitro preparations. The experimental model presented here describes a decerebrate, in vivo adult mouse preparation in which focal, electrical midbrain stimulation was combined with monitoring lumbar neural activity and motor output after pre-collicular decerebration and neuromuscular blockade. Lumbar cord dorsum potentials (in 9/10 animals) and motoneuron output (in 3/5 animals) including fictive locomotion, was achieved by focal midbrain stimulation. The stimulation electrode locations could be reconstructed (in 6/7 animals) thereby allowing anatomical identification of the stimulated supraspinal regions. This preparation allows for concomitant recording or stimulation in the spinal cord and in the mid/hindbrain of adult mice. It differs from other methods used in the past with adult mice as it does not require pharmacological manipulation of neural excitability in order to generate motor output. Midbrain stimulation can consistently be used for inducing lumbar neural activity in adult mice under neuromuscular blockade. This model is suited for examination of brain-spinal connectivity and it may benefit a wide range of fields depending on the features of the genetically modified mouse models used in combination with the presented methods. Copyright © 2017 Elsevier B.V. All rights reserved.

Computational motor control: feedback and accuracy.

PubMed

Guigon, Emmanuel; Baraduc, Pierre; Desmurget, Michel

2008-02-01

Speed/accuracy trade-off is a ubiquitous phenomenon in motor behaviour, which has been ascribed to the presence of signal-dependent noise (SDN) in motor commands. Although this explanation can provide a quantitative account of many aspects of motor variability, including Fitts' law, the fact that this law is frequently violated, e.g. during the acquisition of new motor skills, remains unexplained. Here, we describe a principled approach to the influence of noise on motor behaviour, in which motor variability results from the interplay between sensory and motor execution noises in an optimal feedback-controlled system. In this framework, we first show that Fitts' law arises due to signal-dependent motor noise (SDN(m)) when sensory (proprioceptive) noise is low, e.g. under visual feedback. Then we show that the terminal variability of non-visually guided movement can be explained by the presence of signal-dependent proprioceptive noise. Finally, we show that movement accuracy can be controlled by opposite changes in signal-dependent sensory (SDN(s)) and SDN(m), a phenomenon that could be ascribed to muscular co-contraction. As the model also explains kinematics, kinetics, muscular and neural characteristics of reaching movements, it provides a unified framework to address motor variability.

Structure-function analysis of mouse Sry reveals dual essential roles of the C-terminal polyglutamine tract in sex determination.

PubMed

Zhao, Liang; Ng, Ee Ting; Davidson, Tara-Lynne; Longmuss, Enya; Urschitz, Johann; Elston, Marlee; Moisyadi, Stefan; Bowles, Josephine; Koopman, Peter

2014-08-12

The mammalian sex-determining factor SRY comprises a conserved high-mobility group (HMG) box DNA-binding domain and poorly conserved regions outside the HMG box. Mouse Sry is unusual in that it includes a C-terminal polyglutamine (polyQ) tract that is absent in nonrodent SRY proteins, and yet, paradoxically, is essential for male sex determination. To dissect the molecular functions of this domain, we generated a series of Sry mutants, and studied their biochemical properties in cell lines and transgenic mouse embryos. Sry protein lacking the polyQ domain was unstable, due to proteasomal degradation. Replacing this domain with irrelevant sequences stabilized the protein but failed to restore Sry's ability to up-regulate its key target gene SRY-box 9 (Sox9) and its sex-determining function in vivo. These functions were restored only when a VP16 transactivation domain was substituted. We conclude that the polyQ domain has important roles in protein stabilization and transcriptional activation, both of which are essential for male sex determination in mice. Our data disprove the hypothesis that the conserved HMG box domain is the only functional domain of Sry, and highlight an evolutionary paradox whereby mouse Sry has evolved a novel bifunctional module to activate Sox9 directly, whereas SRY proteins in other taxa, including humans, seem to lack this ability, presumably making them dependent on partner proteins(s) to provide this function.

Transcriptional profiling and biomarker identification reveal tissue specific effects of expanded ataxin-3 in a spinocerebellar ataxia type 3 mouse model.

PubMed

Toonen, Lodewijk J A; Overzier, Maurice; Evers, Melvin M; Leon, Leticia G; van der Zeeuw, Sander A J; Mei, Hailiang; Kielbasa, Szymon M; Goeman, Jelle J; Hettne, Kristina M; Magnusson, Olafur Th; Poirel, Marion; Seyer, Alexandre; 't Hoen, Peter A C; van Roon-Mom, Willeke M C

2018-06-22

Spinocerebellar ataxia type 3 (SCA3) is a progressive neurodegenerative disorder caused by expansion of the polyglutamine repeat in the ataxin-3 protein. Expression of mutant ataxin-3 is known to result in transcriptional dysregulation, which can contribute to the cellular toxicity and neurodegeneration. Since the exact causative mechanisms underlying this process have not been fully elucidated, gene expression analyses in brains of transgenic SCA3 mouse models may provide useful insights. Here we characterised the MJD84.2 SCA3 mouse model expressing the mutant human ataxin-3 gene using a multi-omics approach on brain and blood. Gene expression changes in brainstem, cerebellum, striatum and cortex were used to study pathological changes in brain, while blood gene expression and metabolites/lipids levels were examined as potential biomarkers for disease. Despite normal motor performance at 17.5 months of age, transcriptional changes in brain tissue of the SCA3 mice were observed. Most transcriptional changes occurred in brainstem and striatum, whilst cerebellum and cortex were only modestly affected. The most significantly altered genes in SCA3 mouse brain were Tmc3, Zfp488, Car2, and Chdh. Based on the transcriptional changes, α-adrenergic and CREB pathways were most consistently altered for combined analysis of the four brain regions. When examining individual brain regions, axon guidance and synaptic transmission pathways were most strongly altered in striatum, whilst brainstem presented with strongest alterations in the pi-3 k cascade and cholesterol biosynthesis pathways. Similar to other neurodegenerative diseases, reduced levels of tryptophan and increased levels of ceramides, di- and triglycerides were observed in SCA3 mouse blood. The observed transcriptional changes in SCA3 mouse brain reveal parallels with previous reported neuropathology in patients, but also shows brain region specific effects as well as involvement of adrenergic signalling and CREB pathway changes in SCA3. Importantly, the transcriptional changes occur prior to onset of motor- and coordination deficits.

Automatic analysis of altered gait in arylsulphatase A-deficient mice in the open field.

PubMed

Leroy, Toon; Stroobants, Stijn; Aerts, Jean-Marie; D'Hooge, Rudi; Berckmans, Daniel

2009-08-01

In current research with laboratory animals, observing their dynamic behavior or locomotion is a labor-intensive task. Automatic continuous monitoring can provide quantitative data on each animal's condition and coordination ability. The objective of the present work is to develop an automated mouse observation system integrated with a conventional open-field test for motor function evaluation. Data were acquired from 86 mice having a targeted disruption of the arylsulphatase A (ASA) gene and having lowered coordinated locomotion abilities as a symptom. The mice used were 36 heterozygotes (12 females) and 50 knockout mice (30 females) at the age of 6 months. The mice were placed one at a time into the test setup, which consisted of a Plexiglas cage (53x34.5x26 cm) and two fluorescent bulbs for proper illumination. The transparent cage allowed images to be captured from underneath the cage, so image information could be obtained about the dynamic variation of the positions of the limbs of the mice for gait reconstruction. Every mouse was recorded for 10 min. Background subtraction and color filtering were used to measure and calculate image features, which are variables that contain crucial information, such as the mouse's position, orientation, body outline, and possible locations for the mouse's paws. A set of heuristic rules was used to prune implausible paw features and label the remaining ones as front/hind and left/right. After we had pruned the implausible paw features, the paw features that were consistent over subsequent images were matched to footprints. Finally, from the measured footprint sequence, eight parameters were calculated in order to quantify the gait of the mouse. This automatic observation technique can be integrated with a regular open-field test, where the trajectory and motor function of a free-moving mouse are measured simultaneously.

Improvement to the Standardization Life-Cycle-Cost Model for Hull, Mechanical, and Electrical Components and Equipments.

DTIC Science & Technology

1980-03-01

APL 061900283, Compressor, Motor , AC, 440 V, Valve, Solenoid Centrifugal, 230 gpm Air 300 hp Each C/E was identified to a distinguishable complexity...Deck and Hull Machinery D Rocket Handling Agitator-Paint Shaker Deck and Hull Machinery B Air Conditioner Refrigeration/Heating C Systems Air Ejector...Terminal Electrical Systems a Brake- Air Deck and Hull Machinery D Brake-Electric, Motor Operated Deck and Hull Machinery D Srake-Electric, Solenoid

Mutant HSPB1 causes loss of translational repression by binding to PCBP1, an RNA binding protein with a possible role in neurodegenerative disease.

PubMed

Geuens, Thomas; De Winter, Vicky; Rajan, Nicholas; Achsel, Tilmann; Mateiu, Ligia; Almeida-Souza, Leonardo; Asselbergh, Bob; Bouhy, Delphine; Auer-Grumbach, Michaela; Bagni, Claudia; Timmerman, Vincent

2017-01-11

The small heat shock protein HSPB1 (Hsp27) is an ubiquitously expressed molecular chaperone able to regulate various cellular functions like actin dynamics, oxidative stress regulation and anti-apoptosis. So far disease causing mutations in HSPB1 have been associated with neurodegenerative diseases such as distal hereditary motor neuropathy, Charcot-Marie-Tooth disease and amyotrophic lateral sclerosis. Most mutations in HSPB1 target its highly conserved α-crystallin domain, while other mutations affect the C- or N-terminal regions or its promotor. Mutations inside the α-crystallin domain have been shown to enhance the chaperone activity of HSPB1 and increase the binding to client proteins. However, the HSPB1-P182L mutation, located outside and downstream of the α-crystallin domain, behaves differently. This specific HSPB1 mutation results in a severe neuropathy phenotype affecting exclusively the motor neurons of the peripheral nervous system. We identified that the HSPB1-P182L mutant protein has a specifically increased interaction with the RNA binding protein poly(C)binding protein 1 (PCBP1) and results in a reduction of its translational repressive activity. RNA immunoprecipitation followed by RNA sequencing on mouse brain lead to the identification of PCBP1 mRNA targets. These targets contain larger 3'- and 5'-UTRs than average and are enriched in an RNA motif consisting of the CTCCTCCTCCTCC consensus sequence. Interestingly, next to the clear presence of neuronal transcripts among the identified PCBP1 targets we identified known genes associated with hereditary peripheral neuropathies and hereditary spastic paraplegias. We therefore conclude that HSPB1 can mediate translational repression through interaction with an RNA binding protein further supporting its role in neurodegenerative disease.

Adeno-Associated Viral Vector Serotype DJ-Mediated Overexpression of N171-82Q-Mutant Huntingtin in the Striatum of Juvenile Mice Is a New Model for Huntington's Disease.

PubMed

Jang, Minhee; Lee, Seung Eun; Cho, Ik-Hyun

2018-01-01

Huntington's disease (HD) is an autosomal-dominant inherited neurodegenerative disorder characterized by motor, psychiatric and cognitive symptoms. HD is caused by an expansion of CAG repeats in the huntingtin ( HTT ) gene in various areas of the brain including striatum. There are few suitable animal models to study the pathogenesis of HD and validate therapeutic strategies. Recombinant adeno-associated viral (AAV) vectors successfully transfer foreign genes to the brain of adult mammalians. In this article, we report a novel mouse model of HD generated by bilateral intrastriatal injection of AAV vector serotype DJ (AAV-DJ) containing N171-82Q mutant HTT (82Q) and N171-18Q wild type HTT (18Q; sham). The AAV-DJ-82Q model displayed motor dysfunctions in pole and rotarod tests beginning 4 weeks after viral infection in juvenile mice (8 weeks after birth). They showed behaviors reflecting neurodegeneration. They also showed increased apoptosis, robust glial activation and upregulated representative inflammatory cytokines (tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6), mediators (cyclooxygenase-2 and inducible nitric oxide synthase) and signaling pathways (nuclear factor kappa B and signal transducer and activator of transcription 3 (STAT3)) in the striatum at 10 weeks after viral infection (14 weeks after birth) via successful transfection of mutant HTT into neurons, microglia, and astrocytes in the striatum. However, little evidence of any of these events was found in mice infected with the AAV-DJ-18Q expressing construct. Intrastriatal injection of AAV-DJ-82Q might be useful as a novel in vivo model to investigate the biology of truncated N-terminal fragment (N171) in the striatum and to explore the efficacy of therapeutic strategies for HD.

Effects of Chronic Sleep Restriction during Early Adolescence on the Adult Pattern of Connectivity of Mouse Secondary Motor Cortex123

PubMed Central

Billeh, Yazan N.; Bernard, Amy; de Vivo, Luisa; Honjoh, Sakiko; Mihalas, Stefan; Ng, Lydia; Koch, Christof

2016-01-01

Abstract Cortical circuits mature in stages, from early synaptogenesis and synaptic pruning to late synaptic refinement, resulting in the adult anatomical connection matrix. Because the mature matrix is largely fixed, genetic or environmental factors interfering with its establishment can have irreversible effects. Sleep disruption is rarely considered among those factors, and previous studies have focused on very young animals and the acute effects of sleep deprivation on neuronal morphology and cortical plasticity. Adolescence is a sensitive time for brain remodeling, yet whether chronic sleep restriction (CSR) during adolescence has long-term effects on brain connectivity remains unclear. We used viral-mediated axonal labeling and serial two-photon tomography to measure brain-wide projections from secondary motor cortex (MOs), a high-order area with diffuse projections. For each MOs target, we calculated the projection fraction, a combined measure of passing fibers and axonal terminals normalized for the size of each target. We found no homogeneous differences in MOs projection fraction between mice subjected to 5 days of CSR during early adolescence (P25–P30, ≥50% decrease in daily sleep, n=14) and siblings that slept undisturbed (n=14). Machine learning algorithms, however, classified animals at significantly above chance levels, indicating that differences between the two groups exist, but are subtle and heterogeneous. Thus, sleep disruption in early adolescence may affect adult brain connectivity. However, because our method relies on a global measure of projection density and was not previously used to measure connectivity changes due to behavioral manipulations, definitive conclusions on the long-term structural effects of early CSR require additional experiments. PMID:27351022

Stimulation of Respiratory Motor Output and Ventilation in a Murine Model of Pompe Disease by Ampakines.

PubMed

ElMallah, Mai K; Pagliardini, Silvia; Turner, Sara M; Cerreta, Anthony J; Falk, Darin J; Byrne, Barry J; Greer, John J; Fuller, David D

2015-09-01

Pompe disease results from a mutation in the acid α-glucosidase gene leading to lysosomal glycogen accumulation. Respiratory insufficiency is common, and the current U.S. Food and Drug Administration-approved treatment, enzyme replacement, has limited effectiveness. Ampakines are drugs that enhance α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor responses and can increase respiratory motor drive. Recent work indicates that respiratory motor drive can be blunted in Pompe disease, and thus pharmacologic stimulation of breathing may be beneficial. Using a murine Pompe model with the most severe clinical genotype (the Gaa(-/-) mouse), our primary objective was to test the hypothesis that ampakines can stimulate respiratory motor output and increase ventilation. Our second objective was to confirm that neuropathology was present in Pompe mouse medullary respiratory control neurons. The impact of ampakine CX717 on breathing was determined via phrenic and hypoglossal nerve recordings in anesthetized mice and whole-body plethysmography in unanesthetized mice. The medulla was examined using standard histological methods coupled with immunochemical markers of respiratory control neurons. Ampakine CX717 robustly increased phrenic and hypoglossal inspiratory bursting and reduced respiratory cycle variability in anesthetized Pompe mice, and it increased inspiratory tidal volume in unanesthetized Pompe mice. CX717 did not significantly alter these variables in wild-type mice. Medullary respiratory neurons showed extensive histopathology in Pompe mice. Ampakines stimulate respiratory neuromotor output and ventilation in Pompe mice, and therefore they have potential as an adjunctive therapy in Pompe disease.

Loss of spatacsin function alters lysosomal lipid clearance leading to upper and lower motor neuron degeneration.

PubMed

Branchu, Julien; Boutry, Maxime; Sourd, Laura; Depp, Marine; Leone, Céline; Corriger, Alexandrine; Vallucci, Maeva; Esteves, Typhaine; Matusiak, Raphaël; Dumont, Magali; Muriel, Marie-Paule; Santorelli, Filippo M; Brice, Alexis; El Hachimi, Khalid Hamid; Stevanin, Giovanni; Darios, Frédéric

2017-06-01

Mutations in SPG11 account for the most common form of autosomal recessive hereditary spastic paraplegia (HSP), characterized by a gait disorder associated with various brain alterations. Mutations in the same gene are also responsible for rare forms of Charcot-Marie-Tooth (CMT) disease and progressive juvenile-onset amyotrophic lateral sclerosis (ALS). To elucidate the physiopathological mechanisms underlying these human pathologies, we disrupted the Spg11 gene in mice by inserting stop codons in exon 32, mimicking the most frequent mutations found in patients. The Spg11 knockout mouse developed early-onset motor impairment and cognitive deficits. These behavioral deficits were associated with progressive brain atrophy with the loss of neurons in the primary motor cortex, cerebellum and hippocampus, as well as with accumulation of dystrophic axons in the corticospinal tract. Spinal motor neurons also degenerated and this was accompanied by fragmentation of neuromuscular junctions and muscle atrophy. This new Spg11 knockout mouse therefore recapitulates the full range of symptoms associated with SPG11 mutations observed in HSP, ALS and CMT patients. Examination of the cellular alterations observed in this model suggests that the loss of spatacsin leads to the accumulation of lipids in lysosomes by perturbing their clearance from these organelles. Altogether, our results link lysosomal dysfunction and lipid metabolism to neurodegeneration and pinpoint a critical role of spatacsin in lipid turnover. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Reducing C-terminal truncation mitigates synucleinopathy and neurodegeneration in a transgenic model of multiple system atrophy

PubMed Central

Bassil, Fares; Fernagut, Pierre-Olivier; Bezard, Erwan; Pruvost, Alain; Leste-Lasserre, Thierry; Hoang, Quyen Q.; Ringe, Dagmar; Petsko, Gregory A.; Meissner, Wassilios G.

2016-01-01

Multiple system atrophy (MSA) is a sporadic orphan neurodegenerative disorder. No treatment is currently available to slow down the aggressive neurodegenerative process, and patients die within a few years after disease onset. The cytopathological hallmark of MSA is the accumulation of alpha-synuclein (α-syn) aggregates in affected oligodendrocytes. Several studies point to α-syn oligomerization and aggregation as a mediator of neurotoxicity in synucleinopathies including MSA. C-terminal truncation by the inflammatory protease caspase-1 has recently been implicated in the mechanisms that promote aggregation of α-syn in vitro and in neuronal cell models of α-syn toxicity. We present here an in vivo proof of concept of the ability of the caspase-1 inhibitor prodrug VX-765 to mitigate α-syn pathology and to mediate neuroprotection in proteolipid protein α-syn (PLP-SYN) mice, a transgenic mouse model of MSA. PLP-SYN and age-matched wild-type mice were treated for a period of 11 wk with VX-765 or placebo. VX-765 prevented motor deficits in PLP-SYN mice compared with placebo controls. More importantly, VX-765 was able to limit the progressive toxicity of α-syn aggregation by reducing its load in the striatum of PLP-SYN mice. Not only did VX-765 reduce truncated α-syn, but it also decreased its monomeric and oligomeric forms. Finally, VX-765 showed neuroprotective effects by preserving tyrosine hydroxylase-positive neurons in the substantia nigra of PLP-SYN mice. In conclusion, our results suggest that VX-765, a drug that was well tolerated in a 6 wk-long phase II trial in patients with epilepsy, is a promising candidate to achieve disease modification in synucleinopathies by limiting α-syn accumulation. PMID:27482103

A multiplicity of factors contributes to selective RNA polymerase III occupancy of a subset of RNA polymerase III genes in mouse liver

PubMed Central

Canella, Donatella; Bernasconi, David; Gilardi, Federica; LeMartelot, Gwendal; Migliavacca, Eugenia; Praz, Viviane; Cousin, Pascal; Delorenzi, Mauro; Hernandez, Nouria; Hernandez, Nouria; Delorenzi, Mauro; Deplancke, Bart; Desvergne, Béatrice; Guex, Nicolas; Herr, Winship; Naef, Felix; Rougemont, Jacques; Schibler, Ueli; Deplancke, Bart; Guex, Nicolas; Herr, Winship; Guex, Nicolas; Andersin, Teemu; Cousin, Pascal; Gilardi, Federica; Gos, Pascal; Le Martelot, Gwendal; Lammers, Fabienne; Canella, Donatella; Gilardi, Federica; Raghav, Sunil; Fabbretti, Roberto; Fortier, Arnaud; Long, Li; Vlegel, Volker; Xenarios, Ioannis; Migliavacca, Eugenia; Praz, Viviane; Guex, Nicolas; Naef, Felix; Rougemont, Jacques; David, Fabrice; Jarosz, Yohan; Kuznetsov, Dmitry; Liechti, Robin; Martin, Olivier; Ross, Frederick; Sinclair, Lucas; Cajan, Julia; Krier, Irina; Leleu, Marion; Migliavacca, Eugenia; Molina, Nacho; Naldi, Aurélien; Rey, Guillaume; Symul, Laura; Guex, Nicolas; Naef, Felix; Rougemont, Jacques; Bernasconi, David; Delorenzi, Mauro; Andersin, Teemu; Canella, Donatella; Gilardi, Federica; Le Martelot, Gwendal; Lammers, Fabienne; Raghav, Sunil

2012-01-01

The genomic loci occupied by RNA polymerase (RNAP) III have been characterized in human culture cells by genome-wide chromatin immunoprecipitations, followed by deep sequencing (ChIP-seq). These studies have shown that only ∼40% of the annotated 622 human tRNA genes and pseudogenes are occupied by RNAP-III, and that these genes are often in open chromatin regions rich in active RNAP-II transcription units. We have used ChIP-seq to characterize RNAP-III-occupied loci in a differentiated tissue, the mouse liver. Our studies define the mouse liver RNAP-III-occupied loci including a conserved mammalian interspersed repeat (MIR) as a potential regulator of an RNAP-III subunit-encoding gene. They reveal that synteny relationships can be established between a number of human and mouse RNAP-III genes, and that the expression levels of these genes are significantly linked. They establish that variations within the A and B promoter boxes, as well as the strength of the terminator sequence, can strongly affect RNAP-III occupancy of tRNA genes. They reveal correlations with various genomic features that explain the observed variation of 81% of tRNA scores. In mouse liver, loci represented in the NCBI37/mm9 genome assembly that are clearly occupied by RNAP-III comprise 50 Rn5s (5S RNA) genes, 14 known non-tRNA RNAP-III genes, nine Rn4.5s (4.5S RNA) genes, and 29 SINEs. Moreover, out of the 433 annotated tRNA genes, half are occupied by RNAP-III. Transfer RNA gene expression levels reflect both an underlying genomic organization conserved in dividing human culture cells and resting mouse liver cells, and the particular promoter and terminator strengths of individual genes. PMID:22287103

Cholestenoic acids regulate motor neuron survival via liver X receptors

PubMed Central

Theofilopoulos, Spyridon; Griffiths, William J.; Crick, Peter J.; Yang, Shanzheng; Meljon, Anna; Ogundare, Michael; Kitambi, Satish Srinivas; Lockhart, Andrew; Tuschl, Karin; Clayton, Peter T.; Morris, Andrew A.; Martinez, Adelaida; Reddy, M. Ashwin; Martinuzzi, Andrea; Bassi, Maria T.; Honda, Akira; Mizuochi, Tatsuki; Kimura, Akihiko; Nittono, Hiroshi; De Michele, Giuseppe; Carbone, Rosa; Criscuolo, Chiara; Yau, Joyce L.; Seckl, Jonathan R.; Schüle, Rebecca; Schöls, Ludger; Sailer, Andreas W.; Kuhle, Jens; Fraidakis, Matthew J.; Gustafsson, Jan-Åke; Steffensen, Knut R.; Björkhem, Ingemar; Ernfors, Patrik; Sjövall, Jan; Arenas, Ernest; Wang, Yuqin

2014-01-01

Cholestenoic acids are formed as intermediates in metabolism of cholesterol to bile acids, and the biosynthetic enzymes that generate cholestenoic acids are expressed in the mammalian CNS. Here, we evaluated the cholestenoic acid profile of mammalian cerebrospinal fluid (CSF) and determined that specific cholestenoic acids activate the liver X receptors (LXRs), enhance islet-1 expression in zebrafish, and increase the number of oculomotor neurons in the developing mouse in vitro and in vivo. While 3β,7α-dihydroxycholest-5-en-26-oic acid (3β,7α-diHCA) promoted motor neuron survival in an LXR-dependent manner, 3β-hydroxy-7-oxocholest-5-en-26-oic acid (3βH,7O-CA) promoted maturation of precursors into islet-1+ cells. Unlike 3β,7α-diHCA and 3βH,7O-CA, 3β-hydroxycholest-5-en-26-oic acid (3β-HCA) caused motor neuron cell loss in mice. Mutations in CYP7B1 or CYP27A1, which encode enzymes involved in cholestenoic acid metabolism, result in different neurological diseases, hereditary spastic paresis type 5 (SPG5) and cerebrotendinous xanthomatosis (CTX), respectively. SPG5 is characterized by spastic paresis, and similar symptoms may occur in CTX. Analysis of CSF and plasma from patients with SPG5 revealed an excess of the toxic LXR ligand, 3β-HCA, while patients with CTX and SPG5 exhibited low levels of the survival-promoting LXR ligand 3β,7α-diHCA. Moreover, 3β,7α-diHCA prevented the loss of motor neurons induced by 3β-HCA in the developing mouse midbrain in vivo.Our results indicate that specific cholestenoic acids selectively work on motor neurons, via LXR, to regulate the balance between survival and death. PMID:25271621

Improvement in motor and exploratory behavior in Rett syndrome mice with restricted ketogenic and standard diets.

PubMed

Mantis, John G; Fritz, Christie L; Marsh, Jeremy; Heinrichs, Stephen C; Seyfried, Thomas N

2009-06-01

Rett syndrome (RTT) is a rare X-linked autistic-spectrum neurological disorder associated with impaired energy metabolism, seizure susceptibility, progressive social behavioral regression, and motor impairment primarily in young girls. The objective of this study was to examine the influence of restricted diets, including a ketogenic diet (KD) and a standard rodent chow diet (SD), on behavior in male Mecp2(308/y) mice, a model of RTT. The KD is a high-fat, low-carbohydrate diet that has anticonvulsant efficacy in children with intractable epilepsy and may be therapeutic in children with RTT. Following an 11-day pretrial period, adult wild-type and mutant Rett mice were separated into groups that were fed either an SD in unrestricted or restricted amounts or a ketogenic diet (KetoCal) in restricted amounts for a total of 30 days. The restricted diets were administered to reduce mouse body weight by 20-23% compared to the body weight of each mouse before the initiation of the diet. All mice were subjected to a battery of behavioral tests to determine the influence of the diet on the RTT phenotype. We found that performance in tests of motor behavior and anxiety was significantly worse in male RTT mice compared to wild-type mice and that restriction of either the KD or the SD improved motor behavior and reduced anxiety. We conclude that although both restricted diets increased the tendency of Rett mice to explore a novel environment, the beneficial effects of the KD were due more to calorie restriction than to the composition of the diet. Our findings suggest that calorically restricted diets could be effective in reducing the anxiety and in improving motor behavior in girls with RTT.

Motor deficits, impaired response inhibition, and blunted response to methylphenidate following neonatal exposure to decabromodiphenyl ether.

PubMed

Markowski, Vincent P; Miller-Rhodes, Patrick; Cheung, Randy; Goeke, Calla; Pecoraro, Vincent; Cohen, Gideon; Small, Deena J

2017-09-01

Decabromodiphenyl ether (decaBDE) is an applied brominated flame retardant that is widely-used in electronic equipment. After decades of use, decaBDE and other members of its polybrominated diphenyl ether class have become globally-distributed environmental contaminants that can be measured in the atmosphere, water bodies, wildlife, food staples and human breastmilk. Although it has been banned in Europe and voluntarily withdrawn from the U.S. market, it is still used in Asian countries. Evidence from epidemiological and animal studies indicate that decaBDE exposure targets brain development and produces behavioral impairments. The current study examined an array of motor and learning behaviors in a C57BL6/J mouse model to determine the breadth of the developmental neurotoxicity produced by decaBDE. Mouse pups were given a single daily oral dose of 0 or 20mg/kg decaBDE from postnatal day 1 to 21 and were tested in adulthood. Exposed male mice had impaired forelimb grip strength, altered motor output in a circadian wheel-running procedure, increased response errors during an operant differential reinforcement of low rates (DRL) procedure and a blunted response to an acute methylphenidate challenge administered before DRL testing. With the exception of altered wheel-running output, exposed females were not affected. Neither sex had altered somatic growth, motor coordination impairments on the Rotarod, gross learning deficits during operant lever-press acquisition, or impaired food motivation. The overall pattern of effects suggests that males are more sensitive to developmental decaBDE exposure, especially when performing behaviors that require effortful motor output or when learning tasks that require sufficient response inhibition for their successful completion. Copyright © 2017 Elsevier Inc. All rights reserved.

A novel ALS-associated variant in UBQLN4 regulates motor axon morphogenesis

PubMed Central

Edens, Brittany M; Yan, Jianhua; Miller, Nimrod; Deng, Han-Xiang; Siddique, Teepu; Ma, Yongchao C

2017-01-01

The etiological underpinnings of amyotrophic lateral sclerosis (ALS) are complex and incompletely understood, although contributions to pathogenesis by regulators of proteolytic pathways have become increasingly apparent. Here, we present a novel variant in UBQLN4 that is associated with ALS and show that its expression compromises motor axon morphogenesis in mouse motor neurons and in zebrafish. We further demonstrate that the ALS-associated UBQLN4 variant impairs proteasomal function, and identify the Wnt signaling pathway effector beta-catenin as a UBQLN4 substrate. Inhibition of beta-catenin function rescues the UBQLN4 variant-induced motor axon phenotypes. These findings provide a strong link between the regulation of axonal morphogenesis and a new ALS-associated gene variant mediated by protein degradation pathways. DOI: http://dx.doi.org/10.7554/eLife.25453.001 PMID:28463112

Effects of anodal transcranial direct current stimulation over the leg motor area on lumbar spinal network excitability in healthy subjects

PubMed Central

Roche, N; Lackmy, A; Achache, V; Bussel, B; Katz, R

2011-01-01

Abstract In recent years, two techniques have become available for the non-invasive stimulation of human motor cortex: transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS). The effects of TMS and tDCS when applied over motor cortex should be considered with regard not only to cortical circuits but also to spinal motor circuits. The different modes of action and specificity of TMS and tDCS suggest that their effects on spinal network excitability may be different from that in the cortex. Until now, the effects of tDCS on lumbar spinal network excitability have never been studied. In this series of experiments, on healthy subjects, we studied the effects of anodal tDCS over the lower limb motor cortex on (i) reciprocal Ia inhibition projecting from the tibialis anterior muscle (TA) to the soleus (SOL), (ii) presynaptic inhibition of SOL Ia terminals, (iii) homonymous SOL recurrent inhibition, and (iv) SOL H-reflex recruitment curves. The results show that anodal tDCS decreases reciprocal Ia inhibition, increases recurrent inhibition and induces no modification of presynaptic inhibition of SOL Ia terminals and of SOL-H reflex recruitment curves. Our results indicate therefore that the effects of tDCS are the opposite of those previously described for TMS on spinal network excitability. They also indicate that anodal tDCS induces effects on spinal network excitability similar to those observed during co-contraction suggesting that anodal tDCS activates descending corticospinal projections mainly involved in co-contractions. PMID:21502292

Effects of hindlimb unloading on neuromuscular development of neonatal rats

NASA Technical Reports Server (NTRS)

Huckstorf, B. L.; Slocum, G. R.; Bain, J. L.; Reiser, P. M.; Sedlak, F. R.; Wong-Riley, M. T.; Riley, D. A.

2000-01-01

We hypothesized that hindlimb suspension unloading of 8-day-old neonatal rats would disrupt the normal development of muscle fiber types and the motor innervation of the antigravity (weightbearing) soleus muscles but not extensor digitorum longus (EDL) muscles. Five rats were suspended 4.5 h and returned 1.5 h to the dam for nursing on a 24 h cycle for 9 days. To control for isolation from the dam, the remaining five littermates were removed on the same schedule but not suspended. Another litter of 10 rats housed in the same room provided a vivarium control. Fibers were typed by myofibrillar ATPase histochemistry and immunostaining for embryonic, slow, fast IIA and fast IIB isomyosins. The percentage of multiple innervation and the complexity of singly-innervated motor terminal endings were assessed in silver/cholinesterase stained sections. Unique to the soleus, unloading accelerated production of fast IIA myosin, delayed expression of slow myosin and retarded increases in standardized muscle weight and fiber size. Loss of multiple innervation was not delayed. However, fewer than normal motor nerve endings achieved complexity. Suspended rats continued unloaded hindlimb movements. These findings suggest that motor neurons resolve multiple innervation through nerve impulse activity, whereas the postsynaptic element (muscle fiber) controls endplate size, which regulates motor terminal arborization. Unexpectedly, in the EDL of unloaded rats, transition from embryonic to fast myosin expression was retarded. Suspension-related foot drop, which stretches and chronically loads EDL, may have prevented fast fiber differentiation. These results demonstrate that neuromuscular development of both weightbearing and non-weightbearing muscles in rats is dependent upon and modulated by hindlimb loading.

Therapeutic effects of autologous lymphocytes activated with trastuzumab for xenograft mouse models of human breast cancer.

PubMed

Nakagawa, Shinichiro; Matsuoka, Yusuke; Ichihara, Hideaki; Yoshida, Hitoji; Yoshida, Kenshi; Ueoka, Ryuichi

2013-01-01

Trastuzumab (TTZ) is molecular targeted drug used for metastatic breast cancer patients overexpressing human epidermal growth factor receptor 2 (HER2). Therapeutic effects of lymphocytes activated with TTZ (TTZ-LAK) using xenograft mouse models of human breast cancer (MDA-MB-453) cells were examined in vivo. Remarkable reduction of tumor volume in a xenograft mouse models intravenously treated with TTZ-LAK cells after the subcutaneously inoculated of MDA-MB-453 cells was verified in vivo. The migration of TTZ-LAK cells in tumor of mouse models subcutaneously inoculated MDA-MB-453 cells was observed on the basis of histological analysis using immunostaining with CD-3. Induction of apoptosis in tumor of xenograft mice treated with TTZ-LAK cells was observed in micrographs using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) method. It was noteworthy that the therapeutic effects of TTZ-LAK cells along with apoptosis were obtained for xenograft mouse models of human breast tumor in vivo.

Embryonic mouse pre-metatarsal development in organ culture

NASA Technical Reports Server (NTRS)

Klement, B. J.; Spooner, B. S.

1993-01-01

Embryonic mouse pre-metatarsals were removed from embryos at 13 days of gestation and cultured in a defined, serum-free medium for up to 15 days. By histological analysis, we observe that the cultured pre-metatarsal tissue undergoes a similar developmental profile as pre-metatarsals growing normally in vivo. The initial mesenchyme condensation regions undergo differentiation and morphogenesis to form distinct rods made up of cartilage tissue. A marker of this differentiation step is the synthesis of type II collagen. Metabolic labelling, pepsin digestion, SDS-PAGE, and autoradiography were used to demonstrate this protein when cartilage tissue is present in the cultures. After additional culture time, terminal chondrocyte differentiation and morphogenesis take place in specific regions of the cartilage rods to form bands of hypertrophied chondrocytes. One marker of this differentiation step is the synthesis of the enzyme alkaline phosphatase. We have measured the activity of this enzyme throughout the culture period and see a substantial increase at the time of terminal chondrocyte differentiation. Another feature of hypertrophied chondrocytes is that the matrix around the cells becomes calcified. Calcified matrix in our cultured pre-metatarsals was visualized by staining with alizarin red. By supplementing the defined culture medium with ITS, we observed that terminal chondrocyte differentiation took place in a shorter culture time. Supplementation of the medium with serum results in a similar acceleration of terminal differentiation, and, with additional culture time, an osteoid-like matrix forms around the central region of the rods.

Solo/Trio8, a membrane-associated short isoform of Trio, modulates endosome dynamics and neurite elongation.

PubMed

Sun, Ying-Jie; Nishikawa, Kaori; Yuda, Hideki; Wang, Yu-Lai; Osaka, Hitoshi; Fukazawa, Nobuna; Naito, Akira; Kudo, Yoshihisa; Wada, Keiji; Aoki, Shunsuke

2006-09-01

With DNA microarrays, we identified a gene, termed Solo, that is downregulated in the cerebellum of Purkinje cell degeneration mutant mice. Solo is a mouse homologue of rat Trio8-one of multiple Trio isoforms recently identified in rat brain. Solo/Trio8 contains N-terminal sec14-like and spectrin-like repeat domains followed by a single guanine nucleotide exchange factor 1 (GEF1) domain, but it lacks the C-terminal GEF2, immunoglobulin-like, and kinase domains that are typical of Trio. Solo/Trio8 is predominantly expressed in Purkinje neurons of the mouse brain, and expression begins following birth and increases during Purkinje neuron maturation. We identified a novel C-terminal membrane-anchoring domain in Solo/Trio8 that is required for enhanced green fluorescent protein-Solo/Trio8 localization to early endosomes (positive for both early-endosome antigen 1 [EEA1] and Rab5) in COS-7 cells and primary cultured neurons. Solo/Trio8 overexpression in COS-7 cells augmented the EEA1-positive early-endosome pool, and this effect was abolished via mutation and inactivation of the GEF domain or deletion of the C-terminal membrane-anchoring domain. Moreover, primary cultured neurons transfected with Solo/Trio8 showed increased neurite elongation that was dependent on these domains. These results suggest that Solo/Trio8 acts as an early-endosome-specific upstream activator of Rho family GTPases for neurite elongation of developing Purkinje neurons.

Design and Fabrication of a 200N Thrust Rocket Motor Based on NH4ClO4+Al+HTPB as Solid Propellant

NASA Astrophysics Data System (ADS)

Wahid, Mastura Ab; Ali, Wan Khairuddin Wan

2010-06-01

The development of rocket motor using potassium nitrate, carbon and sulphur mixture has successfully been developed by researchers and students from UTM and recently a new combination for solid propellant is being created. The new solid propellant will combine a composition of Ammonium perchlorate, NH4ClO4 with aluminium, Al and Hydroxyl Terminated Polybutadiene, HTPB as the binder. It is the aim of this research to design and fabricate a new rocket motor that will produce a thrust of 200N by using this new solid propellant. A static test is done to obtain the thrust produced by the rocket motor and analyses by observation and also calculation will be done. The experiment for the rocket motor is successful but the thrust did not achieve its required thrust.

A Genetic Algorithm Approach to Door Assignment in Breakbulk Terminals

DOT National Transportation Integrated Search

2001-08-23

Commercial vehicle regulation and enforcement is a necessary and important function of state governments. Through regulation, states promote highway safety, ensure that motor carriers have the proper licenses and operating permits, and collect taxes ...

Chromatin condensation during terminal erythropoiesis.

PubMed

Zhao, Baobing; Yang, Jing; Ji, Peng

2016-09-02

Mammalian terminal erythropoiesis involves gradual but dramatic chromatin condensation steps that are essential for cell differentiation. Chromatin and nuclear condensation is followed by a unique enucleation process, which is believed to liberate more spaces for hemoglobin enrichment and enable the generation of a physically flexible mature red blood cell. Although these processes have been known for decades, the mechanisms are still unclear. Our recent study reveals an unexpected nuclear opening formation during mouse terminal erythropoiesis that requires caspase-3 activity. Major histones, except H2AZ, are partially released from the opening, which is important for chromatin condensation. Block of the nuclear opening through caspase inhibitor or knockdown of caspase-3 inhibits chromatin condensation and enucleation. We also demonstrate that nuclear opening and histone release are cell cycle regulated. These studies reveal a novel mechanism for chromatin condensation in mammalia terminal erythropoiesis.

Creation of a Mouse with Stress-Induced Dystonia: Control of an ATPase Chaperone

DTIC Science & Technology

2012-10-01

Mice with mutations in genes known to cause dystonia in humans are so far virtually asymptomatic. Only mild motor deficiencies have been seen, such...identified the gene for one of the subunits of Na,K- ATPase, ATP1A3, as the site of mutations in RDP (de Carvalho Aguiar et al. 2004). Our prior work in...first paper, and to be able to give the mouse line an official name based on the mutated gene . Funding has been applied for from the following

Loss of the E3 ubiquitin ligase LRSAM1 sensitizes peripheral axons to degeneration in a mouse model of Charcot-Marie-Tooth disease.

PubMed

Bogdanik, Laurent P; Sleigh, James N; Tian, Cong; Samuels, Mark E; Bedard, Karen; Seburn, Kevin L; Burgess, Robert W

2013-05-01

Charcot-Marie-Tooth disease (CMT) is a clinically and genetically heterogeneous condition characterized by peripheral axon degeneration with subsequent motor and sensory deficits. Several CMT gene products function in endosomal sorting and trafficking to the lysosome, suggesting that defects in this cellular pathway might present a common pathogenic mechanism for these conditions. LRSAM1 is an E3 ubiquitin ligase that is implicated in this process, and mutations in LRSAM1 have recently been shown to cause CMT. We have generated mouse mutations in Lrsam1 to create an animal model of this form of CMT (CMT2P). Mouse Lrsam1 is abundantly expressed in the motor and sensory neurons of the peripheral nervous system. Both homozygous and heterozygous mice have largely normal neuromuscular performance and only a very mild neuropathy phenotype with age. However, Lrsam1 mutant mice are more sensitive to challenge with acrylamide, a neurotoxic agent that causes axon degeneration, indicating that the axons in the mutant mice are indeed compromised. In transfected cells, LRSAM1 primarily localizes in a perinuclear compartment immediately beyond the Golgi and shows little colocalization with components of the endosome to lysosome trafficking pathway, suggesting that other cellular mechanisms also merit consideration.

Motor and cognitive stereotypies in the BTBR T+tf/J mouse model of autism

PubMed Central

Pearson, BL; Pobbe, RLH; Defensor, EB; Oasay, L; Bolivar, VJ; Blanchard, DC; Blanchard, RJ

2010-01-01

The BTBR T+tf/J inbred mouse strain displays a variety of persistent phenotypic alterations similar to those exhibited in autism spectrum disorders. The unique genetic background of the BTBR strain is thought to underlie its lack of reciprocal social interactions, elevated repetitive self-directed grooming and restricted exploratory behaviors. In order to clarify the existence, range and mechanisms of abnormal repetitive behaviors within BTBR mice, we performed detailed analyses of the microstructure of self-grooming patterns and noted increased overall grooming, higher percentages of interruptions in grooming bouts and a concomitant decrease in the proportion of incorrect sequence transitions compared to C57BL/6J inbred mice. Analyses of active phase home cage behavior also revealed an increase in stereotypic bar-biting behavior in the BTBR strain relative to B6 mice. Finally, in a novel object investigation task, BTBR mice exhibited greater baseline preference for specific unfamiliar objects as well as more patterned sequences of sequential investigations of those items. These results suggest that the repetitive, stereotyped behavior patterns of BTBR mice are relatively pervasive and reflect both motor and cognitive mechanisms. Furthermore, other pre-clinical mouse models of autism spectrum disorders may benefit from these more detailed analyses of stereotypic behavior. PMID:21040460

Transgenic mice overexpressing tyrosine-to-cysteine mutant human alpha-synuclein: a progressive neurodegenerative model of diffuse Lewy body disease.

PubMed

Zhou, Wenbo; Milder, Julie B; Freed, Curt R

2008-04-11

Abnormal aggregation of human alpha-synuclein in Lewy bodies and Lewy neurites is a pathological hallmark of Parkinson disease and dementia with Lewy bodies. Studies have shown that oxidation and nitration of alpha-synuclein lead to the formation of stable dimers and oligomers through dityrosine cross-linking. Previously we have reported that tyrosine-to-cysteine mutations, particularly at the tyrosine 39 residue (Y39C), significantly enhanced alpha-synuclein fibril formation and neurotoxicity. In the current study, we have generated transgenic mice expressing the Y39C mutant human alpha-synuclein gene controlled by the mouse Thy1 promoter. Mutant human alpha-synuclein was widely expressed in transgenic mouse brain, resulting in 150% overexpression relative to endogenous mouse alpha-synuclein. At age 9-12 months, transgenic mice began to display motor dysfunction in rotarod testing. Older animals aged 15-18 months showed progressive accumulation of human alpha-synuclein oligomers, associated with worse motor function and cognitive impairment in the Morris water maze. By age 21-24 months, alpha-synuclein aggregates were further increased, accompanied by severe behavioral deficits. At this age, transgenic mice developed neuropathology, such as Lewy body-like alpha-synuclein and ubiquitin-positive inclusions, phosphorylation at Ser(129) of human alpha-synuclein, and increased apoptotic cell death. In summary, Y39C human alpha-synuclein transgenic mice show age-dependent, progressive neuronal degeneration with motor and cognitive deficits similar to diffuse Lewy body disease. The time course of alpha-synuclein oligomer accumulation coincided with behavioral and pathological changes, indicating that these oligomers may initiate protein aggregation, disrupt cellular function, and eventually lead to neuronal death.

Association of dopamine transporter reduction with psychomotor impairment in methamphetamine abusers.

PubMed

Volkow, N D; Chang, L; Wang, G J; Fowler, J S; Leonido-Yee, M; Franceschi, D; Sedler, M J; Gatley, S J; Hitzemann, R; Ding, Y S; Logan, J; Wong, C; Miller, E N

2001-03-01

Methamphetamine is a popular and highly addictive drug of abuse that has raised concerns because it has been shown in laboratory animals to be neurotoxic to dopamine terminals. The authors evaluated if similar changes occur in humans and assessed if they were functionally significant. Positron emission tomography scans following administration of [(11)C]d-threo-methylphenidate (a dopamine transporter ligand) measured dopamine transporter levels (a marker of dopamine cell terminals) in the brains of 15 detoxified methamphetamine abusers and 18 comparison subjects. Neuropsychological tests were also performed to assess motor and cognitive function. Methamphetamine abusers showed significant dopamine transporter reduction in the striatum (mean differences of 27.8% in the caudate and 21.1% in the putamen) relative to the comparison subjects; this reduction was evident even in abusers who had been detoxified for at least 11 months. Dopamine transporter reduction was associated with motor slowing and memory impairment. These results provide evidence that methamphetamine at dose levels taken by human abusers of the drug leads to dopamine transporter reduction that is associated with motor and cognitive impairment. These results emphasize the urgency of alerting clinicians and the public of the long-term changes that methamphetamine can induce in the human brain.

Nonlinear dynamics of C-terminal tails in cellular microtubules

NASA Astrophysics Data System (ADS)

Sekulic, Dalibor L.; Sataric, Bogdan M.; Zdravkovic, Slobodan; Bugay, Aleksandr N.; Sataric, Miljko V.

2016-07-01

The mechanical and electrical properties, and information processing capabilities of microtubules are the permanent subject of interest for carrying out experiments in vitro and in silico, as well as for theoretical attempts to elucidate the underlying processes. In this paper, we developed a new model of the mechano-electrical waves elicited in the rows of very flexible C-terminal tails which decorate the outer surface of each microtubule. The fact that C-terminal tails play very diverse roles in many cellular functions, such as recruitment of motor proteins and microtubule-associated proteins, motivated us to consider their collective dynamics as the source of localized waves aimed for communication between microtubule and associated proteins. Our approach is based on the ferroelectric liquid crystal model and it leads to the effective asymmetric double-well potential which brings about the conditions for the appearance of kink-waves conducted by intrinsic electric fields embedded in microtubules. These kinks can serve as the signals for control and regulation of intracellular traffic along microtubules performed by processive motions of motor proteins, primarly from kinesin and dynein families. On the other hand, they can be precursors for initiation of dynamical instability of microtubules by recruiting the proper proteins responsible for the depolymerization process.

Complex investigation of the effects of lambertianic acid amide in female mice under conditions of social discomfort.

PubMed

Avgustinovich, D F; Fomina, M K; Sorokina, I V; Tolstikova, T G

2014-09-01

The effects of chronic administration of a new substance lambertianic acid amide and previously synthesized methyl ester of this acid were compared in female mice living under conditions of social discomfort. For modeling social discomfort, female mouse was housed for 30 days in a cage with aggressive male mouse kept behind a transparent perforated partition and observed its confrontations with another male mouse daily placed to the cage. The new agent more effectively than lambertianic acid methyl ester improved communicativeness and motor activity of animals, reduced hypertrophy of the adrenal glands, and enhanced catalase activity in the blood. These changes suggest that lambertianic acid amide produces a pronounced stress-protective effect under conditions of social discomfort.

Acf7 (MACF) is an actin and microtubule linker protein whose expression predominates in neural, muscle, and lung development.

PubMed

Bernier, G; Pool, M; Kilcup, M; Alfoldi, J; De Repentigny, Y; Kothary, R

2000-10-01

Several proteins belonging to the plakin family of cytoskeletal linker proteins have recently been identified, including dystonin/Bpag1 and plectin. These proteins are unique in their abilities to form bridges between different cytoskeletal elements through specialized modular domains. We have previously reported the cloning and partial characterization of Acf7, a novel member of the plakin family. More recently, the full-length cDNA for mouse Acf7 has been reported. Acf7 has a hybrid composition, with extended homology to dystonin/Bpag1 and plectin in the N-terminal half, and to dystrophin in the central and C-terminal half. Recent studies have demonstrated that Acf7 has functional actin and microtubule binding domains. Here, we describe the developmental expression profile for mouse Acf7. RNA in situ hybridization experiments revealed Acf7 transcripts in the dermomyotome and neural fold of day 8.5 mouse embryos. Later in development, Acf7 expression was predominant in neural and muscle tissues and was strongly up-regulated just before birth in type II alveolar cells of the lung. Altogether, our results suggest that Acf7 functions as a versatile cytoskeletal linker protein and plays an important role in neural, muscle, and lung development. Copyright 2000 Wiley-Liss, Inc.

Cloning and sequence analysis of Bufo arenarum oviductin cDNA and detection of its orthologous gene expression in the mouse female reproductive tract.

PubMed

Barrera, Daniel; Valdecantos, Pablo A; García, E Vanesa; Miceli, Dora C

2012-02-01

The glycoprotein envelope surrounding the Bufo arenarum egg exists in different functional forms. Conversion between types involves proteolysis of specific envelope glycoproteins. When the egg is released from the ovary, the envelope cannot be penetrated by sperm. Conversion to a penetrable state occurs during passage through the pars recta portion of the oviduct, where oviductin, a serine protease with trypsin-like substrate specificity, hydrolyzes two kinds of envelope glycoproteins: gp84 and gp55. The nucleotide sequence of a 3203 bp B. arenarum oviductin cDNA was obtained. Deduced amino acid sequence showed a complete open reading frame encoding 980 amino acids. B. arenarum oviductin is a multi-domain protein with a protease domain at the N-terminal region followed by two CUB domains and toward the C-terminal region another protease domain, which lacked an active histidine site, and one CUB domain. Expression of ovochymase 2, the mammalian orthologous of amphibian oviductin, was assayed in mouse female reproductive tract. Ovochymase 2 mRNA was unnoticeable in the mouse oviduct but expression was remarkable in the uterus. Phylogenetic relationship between oviductin and ovochymase 2 opens the possibility to understand the role of this enzyme in mammalian reproduction.

Motor learning in animal models of Parkinson’s Disease: Aberrant synaptic plasticity in the motor cortex

PubMed Central

Xu, Tonghui; Wang, Shaofang; Lalchandani, Rupa R.; Ding, Jun B

2017-01-01

In Parkinson’s disease (PD), dopamine depletion causes dramatic changes in the brain resulting in debilitating cognitive and motor deficits. PD neuropathology has been restricted to postmortem examinations, which are limited to only a single time point of PD progression. Models of PD where dopamine tone in the brain are chemically or physically disrupted are valuable tools in understanding the mechanisms of the disease. The basal ganglia have been well studied in the context of PD, and circuit changes in response to dopamine loss have been linked to the motor dysfunctions in PD. However, the etiology of the cognitive dysfunctions that are comorbid in PD patients has remained unclear until now. In this paper, we review recent studies exploring how dopamine depletion affects the motor cortex at the synaptic level. In particular, we highlight our recent findings on abnormal spine dynamics in the motor cortex of PD mouse models through in vivo, time-lapse imaging and motor-skill behavior assays. In combination with previous studies, a role of the motor cortex in skill-learning, and the impairment of this ability with the loss of dopamine, is becoming more apparent. Taken together, we conclude with a discussion on the potential role for the motor cortex in the motor-skill learning and cognitive impairments of PD, with the possibility of targeting the motor cortex for future PD therapeutics. PMID:28343366

Up to Four Distinct Polypeptides Are Produced from the γ34.5 Open Reading Frame of Herpes Simplex Virus 2

PubMed Central

Korom, Maria; Davis, Katie L.

2014-01-01

ABSTRACT The herpes simplex virus 1 (HSV-1) ICP34.5 protein strongly influences neurovirulence and regulates several cellular antiviral responses. Despite the clinical importance of HSV-2, relatively little is known about its ICP34.5 ortholog. We found that HSV-2 produces up to four distinct forms of ICP34.5 in infected cells: a full-length protein, one shorter form sharing the N terminus, and two shorter forms sharing the C terminus. These forms appeared with similar kinetics and accumulated in cells over much of the replication cycle. We confirmed that the N-terminal form is translated from the primary unspliced transcript to a stop codon within the intron unique to HSV-2 γ34.5. We found that the N-terminal form was produced in a variety of cell types and by 9 of 10 clinical isolates. ICP27 influenced but was not required for expression of the N-terminal form. Western blotting and reverse transcription-PCR indicated the C-terminal forms did not contain the N terminus and were not products of alternative splicing or internal transcript initiation. Expression plasmids encoding methionine at amino acids 56 and 70 generated products that comigrated in SDS-PAGE with the C1 and C2 forms, respectively, and mutation of these sites abolished C1 and C2. Using a recombinant HSV-2 encoding hemagglutinin (HA)-tagged ICP34.5, we demonstrated that the C-terminal forms were also produced during infection of many human and mouse cell types but were not detectable in mouse primary neurons. The protein diversity generated from the HSV-2 γ34.5 open reading frame implies additional layers of cellular regulation through potential independent activities associated with the various forms of ICP34.5. IMPORTANCE The herpes simplex virus 1 (HSV-1) protein ICP34.5, encoded by the γ34.5 gene, interferes with several host defense mechanisms by binding cellular proteins that would otherwise stimulate the cell's autophagic, translational-arrest, and type I interferon responses to virus infection. ICP34.5 also plays a crucial role in determining the severity of nervous system infections with HSV-1 and HSV-2. The HSV-2 γ34.5 gene contains an intron not present in HSV-1 γ34.5. A shorter N-terminal form of HSV-2 ICP34.5 can be translated from the unspliced γ34.5 mRNA. Here, we show that two additional forms consisting of the C-terminal portion of ICP34.5 are generated in infected cells. Production of these N- and C-terminal forms is highly conserved among HSV-2 strains, including many clinical isolates, and they are broadly expressed in several cell types, but not mouse primary neurons. Multiple ICP34.5 polypeptides add additional complexity to potential functional interactions influencing HSV-2 neurovirulence. PMID:25031346

Postnatal changes of vesicular glutamate transporter (VGluT)1 and VGluT2 immunoreactivities and their colocalization in the mouse forebrain.

PubMed

Nakamura, Kouichi; Hioki, Hiroyuki; Fujiyama, Fumino; Kaneko, Takeshi

2005-11-21

Vesicular glutamate transporter 1 (VGluT1) and VGluT2 accumulate neurotransmitter glutamate into synaptic vesicles at presynaptic terminals, and their antibodies are thus considered to be a good marker for glutamatergic axon terminals. In the present study, we investigated the postnatal development and maturation of glutamatergic neuronal systems by single- and double-immunolabelings for VGluT1 and VGluT2 in mouse forebrain including the telencephalon and diencephalon. VGluT2 immunoreactivity was widely distributed in the forebrain, particularly in the diencephalon, from postnatal day 0 (P0) to adulthood, suggesting relatively early maturation of VGluT2-loaded glutamatergic axons. In contrast, VGluT1 immunoreactivity was intense only in the limbic regions at P0, and drastically increased in the other telencephalic and diencephalic regions during three postnatal weeks. Interestingly, VGluT1 immunoreactivity was frequently colocalized with VGluT2 immunoreactivity at single axon terminal-like profiles in layer IV of the primary somatosensory area from P5 to P10 and in the ventral posteromedial thalamic nucleus from P0 to P14. This was in sharp contrast to the finding that almost no colocalization was found in glomeruli of the olfactory bulb, patchy regions of the caudate-putamen, and the ventral posterolateral thalamic nucleus, where moderate to intense immunoreactivities for VGluT1 and VGluT2 were intermingled with each other in neuropil during postnatal development. The present results indicate that VGluT2-loaded glutamatergic axons maturate earlier than VGluT1-laden axons in the mouse telencephalic and diencephalic regions, and suggest that VGluT1 plays a transient developmental role in some glutamatergic systems that mainly use VGluT2 in the adulthood. (c) 2005 Wiley-Liss, Inc.

Cerebellar defects in a mouse model of juvenile neuronal ceroid lipofuscinosis.

PubMed

Weimer, Jill M; Benedict, Jared W; Getty, Amanda L; Pontikis, Charlie C; Lim, Ming J; Cooper, Jonathan D; Pearce, David A

2009-04-17

Juvenile neuronal ceroid lipofuscinosis (JNCL), or Batten disease, is a neurodegenerative disease resulting from a mutation in CLN3, which presents clinically with visual deterioration, seizures, motor impairments, cognitive decline, hallucinations, loss of circadian rhythm, and premature death in the late-twenties to early-thirties. Using a Cln3 null (Cln3(-/-)) mouse, we report here several deficits in the cerebellum in the absence of Cln3, including cell loss and early onset motor deficits. Surprisingly, early onset glial activation and selective neuronal loss within the mature fastigial pathway of the deep cerebellar nuclei (DCN), a region critical for balance and coordination, are seen in many regions of the Cln3(-/-) cerebellum. Additionally, there is a loss of Purkinje cells (PC) in regions of robust Bergmann glia activation in Cln3(-/-) mice and human JNCL post-mortem cerebellum. Moreover, the Cln3(-/-) cerebellum had a mis-regulation in granule cell proliferation and maintenance of PC dendritic arborization and spine density. Overall, this study defines a novel multi-faceted, early-onset cerebellar disruption in the Cln3 null brain, including glial activation, cell loss, and aberrant cell proliferation and differentiation. These early alterations in the maturation of the cerebellum could underlie some of the motor deficits and pathological changes seen in JNCL patients.

Maintenance of Mouse Gustatory Terminal Field Organization Is Disrupted following Selective Removal of Peripheral Sodium Salt Taste Activity at Adulthood

PubMed Central

Sun, Chengsan

2017-01-01

Neural activity plays a critical role in the development of central circuits in sensory systems. However, the maintenance of these circuits at adulthood is usually not dependent on sensory-elicited neural activity. Recent work in the mouse gustatory system showed that selectively deleting the primary transduction channel for sodium taste, the epithelial sodium channel (ENaC), throughout development dramatically impacted the organization of the central terminal fields of three nerves that carry taste information to the nucleus of the solitary tract. More specifically, deleting ENaCs during development prevented the normal maturation of the fields. The present study was designed to extend these findings by testing the hypothesis that the loss of sodium taste activity impacts the maintenance of the normal adult terminal field organization in male and female mice. To do this, we used an inducible Cre-dependent genetic recombination strategy to delete ENaC function after terminal field maturation occurred. We found that removal of sodium taste neural activity at adulthood resulted in significant reorganization of mature gustatory afferent terminal fields in the nucleus of the solitary tract. Specifically, the chorda tympani and greater superficial petrosal nerve terminal fields were 1.4× and 1.6× larger than age-matched controls, respectively. By contrast, the glossopharyngeal nerve, which is not highly sensitive to sodium taste stimulation, did not undergo terminal field reorganization. These surprising results suggest that gustatory nerve terminal fields remain plastic well into adulthood, which likely impacts central coding of taste information and taste-related behaviors with altered taste experience. SIGNIFICANCE STATEMENT Neural activity plays a major role in the development of sensory circuits in the mammalian brain. However, the importance of sensory-driven activity in maintaining these circuits at adulthood, especially in subcortical structures, appears to be much less. Here, we tested whether the loss of sodium taste activity in adult mice impacts the maintenance of how taste nerves project to the first central relay. We found that specific loss of sodium-elicited taste activity at adulthood produced dramatic and selective reorganization of terminal fields in the brainstem. This demonstrates, for the first time, that taste-elicited activity is necessary for the normal maintenance of central gustatory circuits at adulthood and highlights a level of plasticity not seen in other sensory system subcortical circuits. PMID:28676575

Nucleotide Crosslinked Polybutadiene for Replacement of Isocyanate-Cured Hydroxyl-Terminated Polybutadiene (HTPB) Systems (Briefing Charts)

DTIC Science & Technology

2014-08-10

sulfur , nitrate salts, carbon (charcoal) – Unreliable ballistic properties – Could not be used in large diameter, high thrust motors • Consolidation of...a programmed manner – Molten Asphalt • Heated to a fluid melt, mixed with oxidant, cast into motor cavity and allowed to cool • Low solids content...which could be formulated • Poor mechanical properties of highly loaded asphalt – Acrylate monomers • Monomers mixed with oxidizers and curative (divinyl

The C-terminal region of the motor protein MCAK controls its structure and activity through a conformational switch

PubMed Central

Talapatra, Sandeep K; Harker, Bethany; Welburn, Julie PI

2015-01-01

The precise regulation of microtubule dynamics is essential during cell division. The kinesin-13 motor protein MCAK is a potent microtubule depolymerase. The divergent non-motor regions flanking the ATPase domain are critical in regulating its targeting and activity. However, the molecular basis for the function of the non-motor regions within the context of full-length MCAK is unknown. Here, we determine the structure of MCAK motor domain bound to its regulatory C-terminus. Our analysis reveals that the MCAK C-terminus binds to two motor domains in solution and is displaced allosterically upon microtubule binding, which allows its robust accumulation at microtubule ends. These results demonstrate that MCAK undergoes long-range conformational changes involving its C-terminus during the soluble to microtubule-bound transition and that the C-terminus-motor interaction represents a structural intermediate in the MCAK catalytic cycle. Together, our work reveals intrinsic molecular mechanisms underlying the regulation of kinesin-13 activity. DOI: http://dx.doi.org/10.7554/eLife.06421.001 PMID:25915621

Converging Mechanisms of p53 Activation Drive Motor Neuron Degeneration in Spinal Muscular Atrophy.

PubMed

Simon, Christian M; Dai, Ya; Van Alstyne, Meaghan; Koutsioumpa, Charalampia; Pagiazitis, John G; Chalif, Joshua I; Wang, Xiaojian; Rabinowitz, Joseph E; Henderson, Christopher E; Pellizzoni, Livio; Mentis, George Z

2017-12-26

The hallmark of spinal muscular atrophy (SMA), an inherited disease caused by ubiquitous deficiency in the SMN protein, is the selective degeneration of subsets of spinal motor neurons. Here, we show that cell-autonomous activation of p53 occurs in vulnerable but not resistant motor neurons of SMA mice at pre-symptomatic stages. Moreover, pharmacological or genetic inhibition of p53 prevents motor neuron death, demonstrating that induction of p53 signaling drives neurodegeneration. At late disease stages, however, nuclear accumulation of p53 extends to resistant motor neurons and spinal interneurons but is not associated with cell death. Importantly, we identify phosphorylation of serine 18 as a specific post-translational modification of p53 that exclusively marks vulnerable SMA motor neurons and provide evidence that amino-terminal phosphorylation of p53 is required for the neurodegenerative process. Our findings indicate that distinct events induced by SMN deficiency converge on p53 to trigger selective death of vulnerable SMA motor neurons. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Monitoring peripheral nerve degeneration in ALS by label-free stimulated Raman scattering imaging

NASA Astrophysics Data System (ADS)

Tian, Feng; Yang, Wenlong; Mordes, Daniel A.; Wang, Jin-Yuan; Salameh, Johnny S.; Mok, Joanie; Chew, Jeannie; Sharma, Aarti; Leno-Duran, Ester; Suzuki-Uematsu, Satomi; Suzuki, Naoki; Han, Steve S.; Lu, Fa-Ke; Ji, Minbiao; Zhang, Rosanna; Liu, Yue; Strominger, Jack; Shneider, Neil A.; Petrucelli, Leonard; Xie, X. Sunney; Eggan, Kevin

2016-10-01

The study of amyotrophic lateral sclerosis (ALS) and potential interventions would be facilitated if motor axon degeneration could be more readily visualized. Here we demonstrate that stimulated Raman scattering (SRS) microscopy could be used to sensitively monitor peripheral nerve degeneration in ALS mouse models and ALS autopsy materials. Three-dimensional imaging of pre-symptomatic SOD1 mouse models and data processing by a correlation-based algorithm revealed that significant degeneration of peripheral nerves could be detected coincidentally with the earliest detectable signs of muscle denervation and preceded physiologically measurable motor function decline. We also found that peripheral degeneration was an early event in FUS as well as C9ORF72 repeat expansion models of ALS, and that serial imaging allowed long-term observation of disease progression and drug effects in living animals. Our study demonstrates that SRS imaging is a sensitive and quantitative means of measuring disease progression, greatly facilitating future studies of disease mechanisms and candidate therapeutics.

Enhancement of SMN protein levels in a mouse model of spinal muscular atrophy using novel drug-like compounds

PubMed Central

Cherry, Jonathan J; Osman, Erkan Y; Evans, Matthew C; Choi, Sungwoon; Xing, Xuechao; Cuny, Gregory D; Glicksman, Marcie A; Lorson, Christian L; Androphy, Elliot J

2013-01-01

Spinal muscular atrophy (SMA) is a neurodegenerative disease that causes progressive muscle weakness, which primarily targets proximal muscles. About 95% of SMA cases are caused by the loss of both copies of the SMN1 gene. SMN2 is a nearly identical copy of SMN1, which expresses much less functional SMN protein. SMN2 is unable to fully compensate for the loss of SMN1 in motor neurons but does provide an excellent target for therapeutic intervention. Increased expression of functional full-length SMN protein from the endogenous SMN2 gene should lessen disease severity. We have developed and implemented a new high-throughput screening assay to identify small molecules that increase the expression of full-length SMN from a SMN2 reporter gene. Here, we characterize two novel compounds that increased SMN protein levels in both reporter cells and SMA fibroblasts and show that one increases lifespan, motor function, and SMN protein levels in a severe mouse model of SMA. PMID:23740718

N-Terminal Truncated UCH-L1 Prevents Parkinson's Disease Associated Damage

PubMed Central

Kim, Hee-Jung; Kim, Hyun Jung; Jeong, Jae-Eun; Baek, Jeong Yeob; Jeong, Jaeho; Kim, Sun; Kim, Young-Mee; Kim, Youhwa; Nam, Jin Han; Huh, Sue Hee; Seo, Jawon; Jin, Byung Kwan; Lee, Kong-Joo

2014-01-01

Ubiquitin C-terminal hydrolase-L1 (UCH-L1) has been proposed as one of the Parkinson's disease (PD) related genes, but the possible molecular connection between UCH-L1 and PD is not well understood. In this study, we discovered an N-terminal 11 amino acid truncated variant UCH-L1 that we called NT-UCH-L1, in mouse brain tissue as well as in NCI-H157 lung cancer and SH-SY5Y neuroblastoma cell lines. In vivo experiments and hydrogen-deuterium exchange (HDX) with tandem mass spectrometry (MS) studies showed that NT-UCH-L1 is readily aggregated and degraded, and has more flexible structure than UCH-L1. Post-translational modifications including monoubiquitination and disulfide crosslinking regulate the stability and cellular localization of NT-UCH-L1, as confirmed by mutational and proteomic studies. Stable expression of NT-UCH-L1 decreases cellular ROS levels and protects cells from H2O2, rotenone and CCCP-induced cell death. NT-UCH-L1-expressing transgenic mice are less susceptible to degeneration of nigrostriatal dopaminergic neurons seen in the MPTP mouse model of PD, in comparison to control animals. These results suggest that NT-UCH-L1 may have the potential to prevent neural damage in diseases like PD. PMID:24959670

Immunogenicity and protective efficacy of rotavirus VP8* fused to cholera toxin B subunit in a mouse model.

PubMed

Xue, Miaoge; Yu, Linqi; Jia, Lianzhi; Li, Yijian; Zeng, Yuanjun; Li, Tingdong; Ge, Shengxiang; Xia, Ningshao

2016-11-01

In attempts to develop recombinant subunit vaccines against rotavirus disease, it was previously shown that the N-terminal truncated VP8* protein, VP8-1 (aa26-231), is a good vaccine candidate when used for immunization in combination with Freund's adjuvant. However, this protein stimulated only weak immune response when aluminum hydroxide was used as an adjuvant. In this study, the nontoxic B subunit of cholera toxin (CTB) was employed as intra-molecular adjuvant to improve the immunogenicity of VP8-1. Both, the N-terminal and C-terminal fusion proteins, were purified to homogeneity, at which stage they formed pentamers, and showed significantly higher immunogenicity and protective efficacy than a VP8-1/aluminum hydroxide mixture in a mouse model. Compared to VP8-1-CTB, CTB-VP8-1 showed higher binding activity to both, GM1 and the conformation sensitive neutralizing monoclonal antibodies specific to VP8. More importantly, CTB-VP8-1 elicited higher titers of neutralizing antibodies and conferred higher protective efficacy than VP8-1-CTB. Therefore, the protein CTB-VP8-1, with enhanced immunogenicity and immunoprotectivity, could be considered as a viable candidate for further development of an alternative, replication-incompetent, parenterally administered vaccine against rotavirus disease.

Major Histocompatibility Complex I Expression by Motor Neurons and Its Implication in Amyotrophic Lateral Sclerosis

PubMed Central

Nardo, Giovanni; Trolese, Maria Chiara; Bendotti, Caterina

2016-01-01

Neuronal expression of major histocompatibility complex I (MHCI)-related molecules in adults and during CNS diseases is involved in the synaptic plasticity and axonal regeneration with mechanisms either dependent or independent of their immune functions. Motor neurons are highly responsive in triggering the expression of MHCI molecules during normal aging or following insults and diseases, and this has implications in the synaptic controls, axonal regeneration, and neuromuscular junction stability of these neurons. We recently reported that MHCI and immunoproteasome are strongly activated in spinal motor neurons and their peripheral motor axon in a mouse model of familial amyotrophic lateral sclerosis (ALS) during the course of the disease. This response was prominent in ALS mice with slower disease progression in which the axonal structure and function was better preserved than in fast-progressing mice. This review summarizes and discusses our observations in the light of knowledge about the possible role of MHCI in motor neurons providing additional insight into the pathophysiology of ALS. PMID:27379008

Knocking down metabotropic glutamate receptor 1 improves survival and disease progression in the SOD1(G93A) mouse model of amyotrophic lateral sclerosis.

PubMed

Milanese, Marco; Giribaldi, Francesco; Melone, Marcello; Bonifacino, Tiziana; Musante, Ilaria; Carminati, Enrico; Rossi, Pia I A; Vergani, Laura; Voci, Adriana; Conti, Fiorenzo; Puliti, Aldamaria; Bonanno, Giambattista

2014-04-01

Amyotrophic lateral sclerosis (ALS) is a late-onset fatal neurodegenerative disease reflecting degeneration of upper and lower motoneurons (MNs). The cause of ALS and the mechanisms of neuronal death are still largely obscure, thus impairing the establishment of efficacious therapies. Glutamate (Glu)-mediated excitotoxicity plays a major role in MN degeneration in ALS. We recently demonstrated that the activation of Group I metabotropic Glu autoreceptors, belonging to both type 1 and type 5 receptors (mGluR1 and mGluR5), at glutamatergic spinal cord nerve terminals, produces excessive Glu release in mice over-expressing human superoxide-dismutase carrying the G93A point mutation (SOD1(G93A)), a widely used animal model of human ALS. To establish whether these receptors are implicated in ALS, we generated mice expressing half dosage of mGluR1 in the SOD1(G93A) background (SOD1(G93A)Grm1(crv4/+)), by crossing the SOD1(G93A) mutant mouse with the Grm1(crv4/+) mouse, lacking mGluR1 because of a spontaneous recessive mutation. SOD1(G93A)Grm1(crv4/+) mice showed prolonged survival probability, delayed pathology onset, slower disease progression and improved motor performances compared to SOD1(G93A) mice. These effects were associated to reduction of mGluR5 expression, enhanced number of MNs, decreased astrocyte and microglia activation, normalization of metallothionein and catalase mRNA expression, reduced mitochondrial damage, and decrease of abnormal Glu release in spinal cord of SOD1(G93A)Grm1(crv4/+)compared to SOD1(G93A) mice. These results demonstrate that a lower constitutive level of mGluR1 has a significant positive impact on mice with experimental ALS, thus providing the rationale for future pharmacological approaches to ALS by selectively blocking Group I metabotropic Glu receptors. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

The structure and organization of lanceolate mechanosensory complexes at mouse hair follicles

PubMed Central

Li, Lishi; Ginty, David D

2014-01-01

In mouse hairy skin, lanceolate complexes associated with three types of hair follicles, guard, awl/auchene and zigzag, serve as mechanosensory end organs. These structures are formed by unique combinations of low-threshold mechanoreceptors (LTMRs), Aβ RA-LTMRs, Aδ-LTMRs, and C-LTMRs, and their associated terminal Schwann cells (TSCs). In this study, we investigated the organization, ultrastructure, and maintenance of longitudinal lanceolate complexes at each hair follicle subtype. We found that TSC processes at hair follicles are tiled and that individual TSCs host axonal endings of more than one LTMR subtype. Electron microscopic analyses revealed unique ultrastructural features of lanceolate complexes that are proposed to underlie mechanotransduction. Moreover, Schwann cell ablation leads to loss of LTMR terminals at hair follicles while, in contrast, TSCs remain associated with hair follicles following skin denervation in adult mice and, remarkably, become re-associated with newly formed axons, indicating a TSC-dependence of lanceolate complex maintenance and regeneration in adults. DOI: http://dx.doi.org/10.7554/eLife.01901.001 PMID:24569481

The crystal structure of a partial mouse Notch-1 ankyrin domain: Repeats 4 through 7 preserve an ankyrin fold

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lubman, Olga Y.; Kopan, Raphael; Waksman, Gabriel

Folding and stability of proteins containing ankyrin repeats (ARs) is of great interest because they mediate numerous protein-protein interactions involved in a wide range of regulatory cellular processes. Notch, an ankyrin domain containing protein, signals by converting a transcriptional repression complex into an activation complex. The Notch ANK domain is essential for Notch function and contains seven ARs. Here, we present the 2.2 {angstrom} crystal structure of ARs 4-7 from mouse Notch 1 (m1ANK). These C-terminal repeats were resistant to degradation during crystallization, and their secondary and tertiary structures are maintained in the absence of repeats 1-3. The crystallized fragmentmore » adopts a typical ankyrin fold including the poorly conserved seventh AR, as seen in the Drosophila Notch ANK domain (dANK). The structural preservation and stability of the C-terminal repeats shed a new light onto the mechanism of hetero-oligomeric assembly during Notch-mediated transcriptional activation.« less

Conformational switching of the pseudokinase domain promotes human MLKL tetramerization and cell death by necroptosis.

PubMed

Petrie, Emma J; Sandow, Jarrod J; Jacobsen, Annette V; Smith, Brian J; Griffin, Michael D W; Lucet, Isabelle S; Dai, Weiwen; Young, Samuel N; Tanzer, Maria C; Wardak, Ahmad; Liang, Lung-Yu; Cowan, Angus D; Hildebrand, Joanne M; Kersten, Wilhelmus J A; Lessene, Guillaume; Silke, John; Czabotar, Peter E; Webb, Andrew I; Murphy, James M

2018-06-21

Necroptotic cell death is mediated by the most terminal known effector of the pathway, MLKL. Precisely how phosphorylation of the MLKL pseudokinase domain activation loop by the upstream kinase, RIPK3, induces unmasking of the N-terminal executioner four-helix bundle (4HB) domain of MLKL, higher-order assemblies, and permeabilization of plasma membranes remains poorly understood. Here, we reveal the existence of a basal monomeric MLKL conformer present in human cells prior to exposure to a necroptotic stimulus. Following activation, toggling within the MLKL pseudokinase domain promotes 4HB domain disengagement from the pseudokinase domain αC helix and pseudocatalytic loop, to enable formation of a necroptosis-inducing tetramer. In contrast to mouse MLKL, substitution of RIPK3 substrate sites in the human MLKL pseudokinase domain completely abrogated necroptotic signaling. Therefore, while the pseudokinase domains of mouse and human MLKL function as molecular switches to control MLKL activation, the underlying mechanism differs between species.

The structure and organization of lanceolate mechanosensory complexes at mouse hair follicles.

PubMed

Li, Lishi; Ginty, David D

2014-02-25

In mouse hairy skin, lanceolate complexes associated with three types of hair follicles, guard, awl/auchene and zigzag, serve as mechanosensory end organs. These structures are formed by unique combinations of low-threshold mechanoreceptors (LTMRs), Aβ RA-LTMRs, Aδ-LTMRs, and C-LTMRs, and their associated terminal Schwann cells (TSCs). In this study, we investigated the organization, ultrastructure, and maintenance of longitudinal lanceolate complexes at each hair follicle subtype. We found that TSC processes at hair follicles are tiled and that individual TSCs host axonal endings of more than one LTMR subtype. Electron microscopic analyses revealed unique ultrastructural features of lanceolate complexes that are proposed to underlie mechanotransduction. Moreover, Schwann cell ablation leads to loss of LTMR terminals at hair follicles while, in contrast, TSCs remain associated with hair follicles following skin denervation in adult mice and, remarkably, become re-associated with newly formed axons, indicating a TSC-dependence of lanceolate complex maintenance and regeneration in adults. DOI: http://dx.doi.org/10.7554/eLife.01901.001.

Structural Basis for the Effective Myostatin Inhibition of the Mouse Myostatin Prodomain-Derived Minimum Peptide.

PubMed

Asari, Tomo; Takayama, Kentaro; Nakamura, Akari; Shimada, Takahiro; Taguchi, Akihiro; Hayashi, Yoshio

2017-01-12

Myostatin inhibition is one of the promising strategies for treating muscle atrophic disorders, including muscular dystrophy. It is well-known that the myostatin prodomain derived from the myostatin precursor acts as an inhibitor of mature myostatin. In our previous study, myostatin inhibitory minimum peptide 1 (WRQNTRYSRIEAIKIQILSKLRL-amide) was discovered from the mouse myostatin prodomain. In the present study, alanine scanning of 1 demonstrated that the key amino acid residues for the effective inhibitory activity are rodent-specific Tyr and C-terminal aliphatic residues, in addition to N-terminal Trp residue. Subsequently, we designed five Pro-substituted peptides and examined the relationship between secondary structure and inhibitory activity. As a result, we found that Pro-substitutions of Ala or Gln residues around the center of 1 significantly decreased both α-helicity and inhibitory activity. These results suggested that an α-helical structure possessing hydrophobic faces formed around the C-terminus is important for inhibitory activity.

ProBDNF and mature BDNF as punishment and reward signals for synapse elimination at mouse neuromuscular junctions.

PubMed

Je, H Shawn; Yang, Feng; Ji, Yuanyuan; Potluri, Srilatha; Fu, Xiu-Qing; Luo, Zhen-Ge; Nagappan, Guhan; Chan, Jia Pei; Hempstead, Barbara; Son, Young-Jin; Lu, Bai

2013-06-12

During development, mammalian neuromuscular junctions (NMJs) transit from multiple-innervation to single-innervation through axonal competition via unknown molecular mechanisms. Previously, using an in vitro model system, we demonstrated that the postsynaptic secretion of pro-brain-derived neurotrophic factor (proBDNF) stabilizes or eliminates presynaptic axon terminals, depending on its proteolytic conversion at synapses. Here, using developing mouse NMJs, we obtained in vivo evidence that proBDNF and mature BDNF (mBDNF) play roles in synapse elimination. We observed that exogenous proBDNF promoted synapse elimination, whereas mBDNF infusion substantially delayed synapse elimination. In addition, pharmacological inhibition of the proteolytic conversion of proBDNF to mBDNF accelerated synapse elimination via activation of p75 neurotrophin receptor (p75(NTR)). Furthermore, the inhibition of both p75(NTR) and sortilin signaling attenuated synapse elimination. We propose a model in which proBDNF and mBDNF serve as potential "punishment" and "reward" signals for inactive and active terminals, respectively, in vivo.

The let-7 microRNA target gene, Mlin41/Trim71 is required for mouse embryonic survival and neural tube closure

PubMed Central

Schulman, Betsy R. Maller; Liang, Xianping; Stahlhut, Carlos; DelConte, Casey; Stefani, Giovanni; Slack, Frank J.

2010-01-01

In the nematode Caenorhabditis elegans, the let-7 microRNA (miRNA) controls the timing of key developmental events and terminal differentiation in part by directly regulating lin-41. C. elegans lin-41 mutants display precocious cell cycle exit and terminal differentiation of epidermal skin cells. lin-41 orthologues are found in more complex organisms including both mice and humans, but their roles are not known. We generated Mlin41 mouse mutants to ascertain a functional role for Mlin41. Strong loss of function Mlin41 gene-trap mutants demonstrated a striking neural tube closure defect during development, and embryonic lethality. Like C. elegans lin-41, Mlin41 also appears to be regulated by the let-7 and mir-125 miRNAs. Since Mlin41 is required for neural tube closure and survival it points to human lin-41 (HLIN41/TRIM71) as a potential human development and disease gene. PMID:19098426

The origin of the post-tetanic hyperpolarization of mammalian motor nerve terminals

PubMed Central

Gage, P. W.; Hubbard, J. I.

1966-01-01

1. Motor nerve terminals in magnesium-poisoned rat hemidiaphragm-phrenic nerve preparations in vitro were stimulated with short depolarizing pulses of approximately threshold strength and the evoked antidromic responses recorded from the phrenic nerve. The percentage of these 1/sec or 0·5/sec stimuli to which there was no antidromic response was used as a quantitative measure of the terminal excitability. After standard tetanic stimulation (1000 impulses at 100/sec) the excitability of the terminals was depressed for an average duration of 60-70 sec, during most of which time no antidromic responses to stimuli of pretetanic intensity were recorded. There was no significant interaction between stimuli to the terminals at rates of 1 or 0·5/sec. 2. Potassium-free solutions at first increased, then decreased, the post-tetanic depression of excitability. Raising [K]o threefold (15 mM) abolished the post-tetanic depression and often converted it to an exaltation of excitability. 3. Polarizing currents were applied to the terminals with a second electrode. Depolarizing currents increased, while hyperpolarizing currents decreased, the post-tetanic depression of excitability. 4. In solutions with 70% of the normal NaCl content replaced by sucrose, the post-tetanic depression of excitability was reversibly prolonged. 5. In the presence of 7·7 × 10-6 M digoxin or 0·42 mM ouabain there was a small reversible reduction of post-tetanic excitability. 6. After exposure to solutions containing no glucose or to solutions containing 3-5 mM sodium azide the excitability of the terminals was not altered by the tetanus. After washing with the control solution, post-tetanic depression of excitability returned. Antimycin-A (1·8 × 10-6 M) had little or no effect upon post-tetanic excitability. 7. It was concluded that the post-tetanic depression of excitability reflected hyperpolarization of the terminals and that this hyperpolarization was caused by a shift of the membrane potential towards the potassium equilibrium potential because of an increase in potassium permeability. ImagesFig. 1 PMID:5921834

Triheptanoin Protects Motor Neurons and Delays the Onset of Motor Symptoms in a Mouse Model of Amyotrophic Lateral Sclerosis

PubMed Central

Barkl-Luke, Mallory E.; Ngo, Shyuan T.; Thomas, Nicola K.; McDonald, Tanya S.; Borges, Karin

2016-01-01

There is increasing evidence that energy metabolism is disturbed in Amyotrophic Lateral Sclerosis (ALS) patients and animal models. Treatment with triheptanoin, the triglyceride of heptanoate, is a promising approach to provide alternative fuel to improve oxidative phosphorylation and aid ATP generation. Heptanoate can be metabolized to propionyl-CoA, which after carboxylation can produce succinyl-CoA and thereby re-fill the tricarboxylic acid (TCA) cycle (anaplerosis). Here we tested the hypothesis that treatment with triheptanoin prevents motor neuron loss and delays the onset of disease symptoms in female mice overexpressing the mutant human SOD1G93A (hSOD1G93A) gene. When oral triheptanoin (35% of caloric content) was initiated at P35, motor neuron loss at 70 days of age was attenuated by 33%. In untreated hSOD1G93A mice, the loss of hind limb grip strength began at 16.7 weeks. Triheptanoin maintained hind limb grip strength for 2.8 weeks longer (p<0.01). Loss of balance on the rotarod and reduction of body weight were delayed by 13 and 11 days respectively (both p<0.01). Improved motor function occurred in parallel with alterations in the expression of genes associated with muscle metabolism. In gastrocnemius muscles, the mRNA levels of pyruvate, 2-oxoglutarate and succinate dehydrogenases and methyl-malonyl mutase were reduced by 24–33% in 10 week old hSOD1G93A mice when compared to wild-type mice, suggesting that TCA cycling in skeletal muscle may be slowed in this ALS mouse model at a stage when muscle strength is still normal. At 25 weeks of age, mRNA levels of succinate dehydrogenases, glutamic pyruvic transaminase 2 and the propionyl carboxylase β subunit were reduced by 69–84% in control, but not in triheptanoin treated hSOD1G93A animals. Taken together, our results suggest that triheptanoin slows motor neuron loss and the onset of motor symptoms in ALS mice by improving TCA cycling. PMID:27564703

Sleep promotes branch-specific formation of dendritic spines after learning

PubMed Central

Yang, Guang; Lai, Cora Sau Wan; Cichon, Joseph; Ma, Lei; Li, Wei; Gan, Wen-Biao

2015-01-01

How sleep helps learning and memory remains unknown. We report in mouse motor cortex that sleep after motor learning promotes the formation of postsynaptic dendritic spines on a subset of branches of individual layer V pyramidal neurons. New spines are formed on different sets of dendritic branches in response to different learning tasks and are protected from being eliminated when multiple tasks are learned. Neurons activated during learning of a motor task are reactivated during subsequent non-rapid eye movement sleep, and disrupting this neuronal reactivation prevents branch-specific spine formation. These findings indicate that sleep has a key role in promoting learning-dependent synapse formation and maintenance on selected dendritic branches, which contribute to memory storage. PMID:24904169

A role of carboxy-terminal region of Toxoplasma gondii-heat shock protein 70 in enhancement of T. gondii infection in mice

PubMed Central

Mun, Hye-Seong; Norose, Kazumi; Aosai, Fumie; Chen, Mei

2000-01-01

We investigated the role of recombinant Toxoplasma gondii heat shock protein (rT.g.HSP) 70-full length, rT.g.HSP70-NH2-terminal region, or rT.g.HSP70-carboxy-terminal region in prophylactic immunity in C57BL/6 mice perorally infected with Fukaya cysts of T. gondii. At 3, 4, 5, and 6 weeks after infection, the number of T. gondii in the brain tissue of each mouse was measured by quantitative competitive-polymerase chain reaction (QC-PCR) targeting the surface antigen (SAG) 1 gene. Immunization with rT.g.HSP70-full length or rT.g.HSP70-carboxy-terminal region increased the number of T.gondii in the brain tissue after T. gondii infection, whereas immunization with rT.g.HSP70-NH2-terminal region did not. These results suggest that T.g.HSP70-carboxy-terminal region as well as T.g.HSP70-full length may induce deleterious effects on the protective immunity of mice infected with a cyst-forming T. gondii strain, Fukaya. PMID:10905074

Sensorimotor assessment of the unilateral 6-hydroxydopamine mouse model of Parkinson’s disease

PubMed Central

Glajch, Kelly E.; Fleming, Sheila M.; Surmeier, D. James; Osten, Pavel

2012-01-01

Parkinson’s disease (PD), the second most common neurodegenerative disorder, is characterized by marked impairments in motor function caused by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta (SNc). Animal models of PD have traditionally been based on toxins, such as 6-hydroxydopamine (6-OHDA) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), that selectively lesion dopaminergic neurons. Motor impairments from 6-OHDA lesions of SNc neurons are well characterized in rats, but much less work has been done in mice. In this study, we compare the effectiveness of a series of drug-free behavioral tests in assessing sensorimotor impairments in the unilateral 6-OHDA mouse model, including six tests used for the first time in this PD mouse model (the automated treadmill “DigiGait” test, the challenging beam test, the adhesive removal test, the pole test, the adjusting steps test, and the test of spontaneous activity) and two tests used previously in 6-OHDA-lesioned mice (the limb-use asymmetry “cylinder” test and the manual gait test). We demonstrate that the limb-use asymmetry, challenging beam, pole, adjusting steps, and spontaneous activity tests are all highly robust assays for detecting sensorimotor impairments in the 6-OHDA mouse model. We also discuss the use of the behavioral tests for specific experimental objectives, such as simple screening for well-lesioned mice in studies of PD cellular pathophysiology or comprehensive behavioral analysis in preclinical therapeutic testing using a battery of sensorimotor tests. PMID:22178078

The PPARgamma agonist pioglitazone is effective in the MPTP mouse model of Parkinson's disease through inhibition of monoamine oxidase B.

PubMed

Quinn, L P; Crook, B; Hows, M E; Vidgeon-Hart, M; Chapman, H; Upton, N; Medhurst, A D; Virley, D J

2008-05-01

The peroxisome proliferator-activated receptor-gamma (PPARgamma) agonist pioglitazone has previously been shown to attenuate dopaminergic cell loss in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson's disease, an effect attributed to its anti-inflammatory properties. In the present investigation, we provide evidence that pioglitazone is effective in the MPTP mouse model, not via an anti-inflammatory action, but through inhibition of MAO-B, the enzyme required to biotransform MPTP to its active neurotoxic metabolite 1-methyl-4-phenylpyridinium (MPP+). Mice were treated with pioglitazone (20 mg kg(-1) b.i.d. (twice a day), p.o., for 7 days), prior and post or post-MPTP (30 mg kg(-1) s.c.) treatment. Mice were then assessed for motor impairments on a beam-walking apparatus and for reductions in TH immunoreactivity in the substantia nigra and depletions in striatal dopamine. The effects of pioglitazone on striatal MPP+ levels and MAO-B activity were also assessed. Mice treated with MPTP showed deficits in motor performance, marked depletions in striatal dopamine levels and a concomitant reduction in TH immunoreactivity in the substantia nigra. Pretreatment with pioglitazone completely prevented these effects of MPTP. However, pretreatment with pioglitazone also significantly inhibited the MPTP-induced production of striatal MPP+ and the activity of MAO-B in the striatum. The neuroprotection observed with pioglitazone pretreatment in the MPTP mouse model was due to the blockade of the conversion of MPTP to its active toxic metabolite MPP+, via inhibition of MAO-B.

Genetic Correction of Human Induced Pluripotent Stem Cells from Patients with Spinal Muscular Atrophy

PubMed Central

Corti, Stefania; Nizzardo, Monica; Simone, Chiara; Falcone, Marianna; Nardini, Martina; Ronchi, Dario; Donadoni, Chiara; Salani, Sabrina; Riboldi, Giulietta; Magri, Francesca; Menozzi, Giorgia; Bonaglia, Clara; Rizzo, Federica; Bresolin, Nereo; Comi, Giacomo P.

2016-01-01

Spinal muscular atrophy (SMA) is among the most common genetic neurological diseases that cause infant mortality. Induced pluripotent stem cells (iPSCs) generated from skin fibroblasts from SMA patients and genetically corrected have been proposed to be useful for autologous cell therapy. We generated iPSCs from SMA patients (SMA-iPSCs) using nonviral, nonintegrating episomal vectors and used a targeted gene correction approach based on single-stranded oligonucleotides to convert the survival motor neuron 2 (SMN2) gene into an SMN1-like gene. Corrected iPSC lines contained no exogenous sequences. Motor neurons formed by differentiation of uncorrected SMA-iPSCs reproduced disease-specific features. These features were ameliorated in motor neurons derived from genetically corrected SMA-iPSCs. The different gene splicing profile in SMA-iPSC motor neurons was rescued after genetic correction. The transplantation of corrected motor neurons derived from SMA-iPSCs into an SMA mouse model extended the life span of the animals and improved the disease phenotype. These results suggest that generating genetically corrected SMA-iPSCs and differentiating them into motor neurons may provide a source of motor neurons for therapeutic transplantation for SMA. PMID:23253609

A Motor-Driven Mechanism for Cell-Length Sensing

PubMed Central

Rishal, Ida; Kam, Naaman; Perry, Rotem Ben-Tov; Shinder, Vera; Fisher, Elizabeth M.C.; Schiavo, Giampietro; Fainzilber, Mike

2012-01-01

Summary Size homeostasis is fundamental in cell biology, but it is not clear how large cells such as neurons can assess their own size or length. We examined a role for molecular motors in intracellular length sensing. Computational simulations suggest that spatial information can be encoded by the frequency of an oscillating retrograde signal arising from a composite negative feedback loop between bidirectional motor-dependent signals. The model predicts that decreasing either or both anterograde or retrograde signals should increase cell length, and this prediction was confirmed upon application of siRNAs for specific kinesin and/or dynein heavy chains in adult sensory neurons. Heterozygous dynein heavy chain 1 mutant sensory neurons also exhibited increased lengths both in vitro and during embryonic development. Moreover, similar length increases were observed in mouse embryonic fibroblasts upon partial downregulation of dynein heavy chain 1. Thus, molecular motors critically influence cell-length sensing and growth control. PMID:22773964

The mouse Pol I terminator is more efficient than the hepatitis delta virus ribozyme in generating influenza-virus-like RNAs with precise 3' ends in a plasmid-only-based virus rescue system.

PubMed

Feng, Liqiang; Li, Feng; Zheng, Xuehua; Pan, Weiqi; Zhou, Kai; Liu, Yichu; He, Hongxuan; Chen, Ling

2009-01-01

Reverse genetics systems for generating recombinant influenza viruses are based on two different mechanisms for obtaining the 3' end of the viral RNA: one uses the self-cleaving hepatitis delta virus ribozyme (HDVR), and the other uses the murine RNA polymerase I (Pol I) terminator. In this study, we employed EGFP and Renilla luciferase reporter constructs to compare the efficiency of both methods. Our results indicate that the murine Pol I terminator was more efficient than the HDVR, which will be helpful in choosing an influenza virus rescue system, as well as in establishing other RNA virus rescue systems.

78 FR 8410 - Thiacloprid; Pesticide Tolerances

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-06

...) were noted in dog, rat, and mouse studies. Increased prostate weight and prostatic hypertrophy were... acetylcholine receptors. In the neurotoxicity studies in rats, there was a reduction in motor and locomotor... uterine tumors in rats, thyroid follicular adenomas in rat and ovarian tumors in mice. A cancer slope...

Genetic inactivation of mGlu5 receptor improves motor coordination in the Grm1crv4 mouse model of SCAR13 ataxia.

PubMed

Bossi, Simone; Musante, Ilaria; Bonfiglio, Tommaso; Bonifacino, Tiziana; Emionite, Laura; Cerminara, Maria; Cervetto, Chiara; Marcoli, Manuela; Bonanno, Giambattista; Ravazzolo, Roberto; Pittaluga, Anna; Puliti, Aldamaria

2018-01-01

Deleterious mutations in the glutamate receptor metabotropic 1 gene (GRM1) cause a recessive form of cerebellar ataxia, SCAR13. GRM1 and GRM5 code for the metabotropic glutamate type 1 (mGlu1) and type 5 (mGlu5) receptors, respectively. Their different expression profiles suggest they could have distinct functional roles. In a previous study, homozygous mice lacking mGlu1 receptors (Grm1 crv4/crv4 ) and exhibiting ataxia presented cerebellar overexpression of mGlu5 receptors, that was proposed to contribute to the mouse phenotype. To test this hypothesis, we here crossed Grm1 crv4 and Grm5 ko mice to generate double mutants (Grm1 crv4/crv4 Grm5 ko/ko ) lacking both mGlu1 and mGlu5 receptors. Double mutants and control mice were analyzed for spontaneous behavior and for motor activity by rotarod and footprint analyses. In the same mice, the release of glutamate from cerebellar nerve endings (synaptosomes) elicited by 12mM KCl or by α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) was also evaluated. Motor coordination resulted improved in double mutants when compared to Grm1 crv4/crv4 mice. Furthermore, in in vitro studies, glutamate release elicited by both KCl depolarization and activation of AMPA autoreceptors resulted reduced in Grm1 crv4/crv4 mice compared to wild type mice, while it presented normal levels in double mutants. Moreover, we found that Grm1 crv4/crv4 mice showed reduced expression of GluA2/3 AMPA receptor subunits in cerebellar synaptosomes, while it resulted restored to wild type level in double mutants. To conclude, blocking of mGlu5 receptor reduced the dysregulation of glutamate transmission and improved motor coordination in the Grm1 crv4 mouse model of SCAR13, thus suggesting the possible usefulness of pharmacological therapies based on modulation of mGlu5 receptor activity for the treatment of this type of ataxia. Copyright © 2017 Elsevier Inc. All rights reserved.

Targeting Extracellular Cyclophilin A Reduces Neuroinflammation and Extends Survival in a Mouse Model of Amyotrophic Lateral Sclerosis.

PubMed

Pasetto, Laura; Pozzi, Silvia; Castelnovo, Mariachiara; Basso, Manuela; Estevez, Alvaro G; Fumagalli, Stefano; De Simoni, Maria Grazia; Castellaneta, Valeria; Bigini, Paolo; Restelli, Elena; Chiesa, Roberto; Trojsi, Francesca; Monsurrò, Maria Rosaria; Callea, Leonardo; Malešević, Miroslav; Fischer, Gunter; Freschi, Mattia; Tortarolo, Massimo; Bendotti, Caterina; Bonetto, Valentina

2017-02-08

Neuroinflammation is a major hallmark of amyotrophic lateral sclerosis (ALS), which is currently untreatable. Several anti-inflammatory compounds have been evaluated in patients and in animal models of ALS, but have been proven disappointing in part because effective targets have not yet been identified. Cyclophilin A, also known as peptidylprolyl cis-/trans-isomerase A (PPIA), as a foldase is beneficial intracellularly, but extracellularly has detrimental functions. We found that extracellular PPIA is a mediator of neuroinflammation in ALS. It is a major inducer of matrix metalloproteinase 9 and is selectively toxic for motor neurons. High levels of PPIA were found in the CSF of SOD1 G93A mice and rats and sporadic ALS patients, suggesting that our findings may be relevant for familial and sporadic cases. A specific inhibitor of extracellular PPIA, MM218, given at symptom onset, rescued motor neurons and extended survival in the SOD1 G93A mouse model of familial ALS by 11 d. The treatment resulted in the polarization of glia toward a prohealing phenotype associated with reduced NF-κB activation, proinflammatory markers, endoplasmic reticulum stress, and insoluble phosphorylated TDP-43. Our results indicates that extracellular PPIA is a promising druggable target for ALS and support further studies to develop a therapy to arrest or slow the progression of the disease in patients. SIGNIFICANCE STATEMENT We provide evidence that extracellular cyclophilin A, also known as peptidylprolyl cis-/trans-isomerase A (PPIA), is a mediator of the neuroinflammatory reaction in amyotrophic lateral sclerosis (ALS) and is toxic for motor neurons. Supporting this, a specific extracellular PPIA inhibitor reduced neuroinflammation, rescued motor neurons, and extended survival in the SOD1 G93A mouse model of familial ALS. Our findings suggest selective pharmacological inhibition of extracellular PPIA as a novel therapeutic strategy, not only for SOD1-linked ALS, but possibly also for sporadic ALS. This approach aims to address the neuroinflammatory reaction that is a major hallmark of ALS. However, given the complexity of the disease, a combination of therapeutic approaches may be necessary. Copyright © 2017 the authors 0270-6474/17/371414-15$15.00/0.

PROGRAMMED CELL DEATH IN EXTRAOCULAR MUSCLE TENDON/SCLERA PRECURSORS

EPA Science Inventory

Abstract

Purpose: This study was designed to examine the occurrence of natural cell death in the periocular mesenchyme of mouse embryos.

Methods: Vital staining with LysoTracker Red and Nile blue sulphate as well as terminal nick end labeling (TUNEL) were utiliz...

INSPECTION MEANS FOR INDUCTION MOTORS

DOEpatents

Williams, A.W.

1959-03-10

an appartus is descripbe for inspcting electric motors and more expecially an appartus for detecting falty end rings inn suqirrel cage inductio motors while the motor is running. In its broua aspects, the mer would around ce of reference tedtor means also itons in the phase ition of the An electronic circuit for conversion of excess-3 binary coded serial decimal numbers to straight binary coded serial decimal numbers is reported. The converter of the invention in its basic form generally coded pulse words of a type having an algebraic sign digit followed serially by a plurality of decimal digits in order of decreasing significance preceding a y algebraic sign digit followed serially by a plurality of decimal digits in order of decreasing significance. A switching martix is coupled to said input circuit and is internally connected to produce serial straight binary coded pulse groups indicative of the excess-3 coded input. A stepping circuit is coupled to the switching matrix and to a synchronous counter having a plurality of x decimal digit and plurality of y decimal digit indicator terminals. The stepping circuit steps the counter in synchornism with the serial binary pulse group output from the switching matrix to successively produce pulses at corresponding ones of the x and y decimal digit indicator terminals. The combinations of straight binary coded pulse groups and corresponding decimal digit indicator signals so produced comprise a basic output suitable for application to a variety of output apparatus.

Vagal gustatory reflex circuits for intraoral food sorting behavior in the goldfish: cellular organization and neurotransmitters.

PubMed

Ikenaga, Takanori; Ogura, Tatsuya; Finger, Thomas E

2009-09-20

The sense of taste is crucial in an animal's determination as to what is edible and what is not. This gustatory function is especially important in goldfish, who utilize a sophisticated oropharyngeal sorting mechanism to separate food from substrate material. The computational aspects of this detection are carried out by the medullary vagal lobe, which is a large, laminated structure combining elements of both the gustatory nucleus of the solitary tract and the nucleus ambiguus. The sensory layers of the vagal lobe are coupled to the motor layers via a simple reflex arc. Details of this reflex circuit were investigated with histology and calcium imaging. Biocytin injections into the motor layer labeled vagal reflex interneurons that have radially directed dendrites ramifying within the layers of primary afferent terminals. Axons of reflex interneurons extend radially inward to terminate onto both vagal motoneurons and small, GABAergic interneurons in the motor layer. Functional imaging shows increases in intracellular Ca++ of vagal motoneurons following electrical stimulation in the sensory layer. These responses were suppressed under Ca(++)-free conditions and by interruption of the axons bridging between the sensory and motor layers. Pharmacological experiments showed that glutamate acting via (+/-)-alpha-amino-3-hydroxy- 5-ethylisoxazole-4-propioinc acid (AMPA)/kainate and N-methyl-D-aspartic acid (NMDA) receptors mediate neurotransmission between reflex interneurons and vagal motoneurons. Thus, the vagal gustatory portion of the viscerosensory complex is linked to branchiomotor neurons of the pharynx via a glutamatergic interneuronal system.

Vagal gustatory reflex circuits for intraoral food sorting behavior in the goldfish Cellular organization and neurotransmitters

PubMed Central

Ikenaga, Takanori; Ogura, Tatsuya; Finger, Thomas E.

2009-01-01

The sense of taste is crucial in an animal’s determination as to what is edible and what is not. This gustatory function is especially important in goldfish who utilize a sophisticated oropharyngeal sorting mechanism to separate food from substrate material. The computational aspects of this detection are carried out by the medullary vagal lobe which is a large, laminated structure combining elements of both the gustatory nucleus of the solitary tract and the nucleus ambiguus. The sensory layers of the vagal lobe are coupled to the motor layers via a simple reflex arc. Details of this reflex circuit were investigated with histology and calcium imaging. Biocytin injections into the motor layer labeled vagal reflex interneurons which have radially-directed dendrites ramifying within the layers of primary afferent terminals. Axons of reflex interneurons extend radially inward to terminate onto both vagal motoneurons and small, GABAergic interneurons in the motor layer. Functional imaging shows increases in intracellular Ca++ of vagal motoneurons following electrical stimulation in the sensory layer. These responses were suppressed under Ca++-free conditions and by interruption of the axons bridging between the sensory and motor layers. Pharmacological experiments showed that glutamate acting via (±)-α-amino-3-hydroxy-5-ethylisoxazole-4-propioinc acid (AMPA)/kainate and N-methyl-D-aspartic acid (NMDA) receptors mediates neurotransmission between reflex interneurons and vagal motoneurons. Thus the vagal gustatory portion of the viscerosensory complex is linked to branchiomotor neurons of the pharynx via a glutamatergic interneuronal system. PMID:19598285

Functional Architecture of the Outer Arm Dynein Conformational Switch*

PubMed Central

King, Stephen M.; Patel-King, Ramila S.

2012-01-01

Dynein light chain 1 (LC1/DNAL1) is one of the most highly conserved components of ciliary axonemal outer arm dyneins, and it associates with both a heavy chain motor unit and tubulin located within the A-tubule of the axonemal outer doublet microtubules. In a variety of model systems, lack of LC1 or expression of mutant forms leads to profound defects in ciliary motility, including the failure of the hydrodynamic coupling needed for ciliary metachronal synchrony, random stalling during the power/recovery stroke transition, an aberrant response to imposed viscous load, and in some cases partial failure of motor assembly. These phenotypes have led to the proposal that LC1 acts as part of a mechanical switch to control motor function in response to alterations in axonemal curvature. Here we have used NMR chemical shift mapping to define the regions perturbed by a series of mutations in the C-terminal domain that yield a range of phenotypic effects on motility. In addition, we have identified the subdomain of LC1 involved in binding microtubules and characterized the consequences of an Asn → Ser alteration within the terminal leucine-rich repeat that in humans causes primary ciliary dyskinesia. Together, these data define a series of functional subdomains within LC1 and allow us to propose a structural model for the organization of the dynein heavy chain-LC1-microtubule ternary complex that is required for the coordinated activity of dynein motors in cilia. PMID:22157010

Therapeutic Effects of Anthocyanins and Environmental Enrichment in R6/1 Huntington's Disease Mice.

PubMed

Kreilaus, Fabian; Spiro, Adena S; Hannan, Anthony J; Garner, Brett; Jenner, Andrew M

2016-10-01

Huntington's disease (HD) is a progressive neurodegenerative disease with no effective treatment or cure. Environmental enrichment has been used to slow processes leading to ageing and neurodegenerative diseases including HD. Phenolic phytochemicals including anthocyanins have also been shown to improve brain function in ageing and neurodegenerative diseases. This study examined the effects of anthocyanin dietary supplementation and environmental enrichment on behavioural phenotypes and brain cholesterol metabolic alterations in the R6/1 mouse model of HD. R6/1 HD mice and their wild-type littermate controls were randomised into the different experimental conditions, involving either environmentally enriched versus standard housing conditions, or anthocyanin versus control diet. Motor dysfunction was assessed from 6 to 26 weeks using the RotaRod and the hind-paw clasping tests. Gas chromatography - tandem mass spectrometry was used to quantify a broad range of sterols in the striatum and cortex of R6/1 HD mice. Anthocyanin dietary supplementation delayed the onset of motor dysfunction in female HD mice. Environmental enrichment improved motor function and the hind paw clasping phenotype in male HD mice only. These mice also had lower levels of cholesterol oxidation products in the cortex compared to standard-housed mice. Both anthocyanin supplementation and environmental enrichment are able to improve the motor dysfunction phenotype of R6/1 mice, however the effectiveness of these interventions was different between the two sexes. The interventions examined did not alter brain cholesterol metabolic deficits that have been reported previously in this mouse model of HD.

Compensatory molecular and functional mechanisms in nervous system of the Grm1(crv4) mouse lacking the mGlu1 receptor: a model for motor coordination deficits.

PubMed

Rossi, Pia Irene Anna; Musante, Ilaria; Summa, Maria; Pittaluga, Anna; Emionite, Laura; Ikehata, Masami; Rastaldi, Maria Pia; Ravazzolo, Roberto; Puliti, Aldamaria

2013-09-01

The metabotropic glutamate type 1 (mGlu1) and type 5 (mGlu5) receptors, the only members of group I mGlu receptors, are implicated in synaptic plasticity and mechanisms of feedback control of glutamate release. They exhibit nearly complementary distributions throughout the central nervous system, well evident in the cerebellum, where mGlu1 receptor is most intensely expressed while mGlu5 receptor is not. Despite their different distribution, they show a similar subcellular localization and use common transducing pathways. We recently described the Grm1(crv4) mouse with motor coordination deficits and renal anomalies caused by a spontaneous mutation inactivating the mGlu1 receptor. To define the neuropathological mechanisms in these mice, we evaluated expression and function of the mGlu5 receptor in cerebral and cerebellar cortices. Western blot and immunofluorescence analyses showed mGlu5 receptor overexpression. Quantitative reverse transcriptase-polymerase chain reaction results indicated that the up-regulation is already evident at RNA level. Functional studies confirmed an enhanced glutamate release from cortical cerebral and cerebellar synaptosomes when compared with wild-type that is abolished by the mGlu5 receptor-specific inhibitor, 2-methyl-6-(phenylethynyl) pyridine hydrochloride (MPEP). Finally, acute MPEP treatment of Grm1(crv4/crv4) mice induced an evident although incomplete improvement of motor coordination, suggesting that mGlu5 receptors enhanced activity worsens, instead of improving, the motor-coordination defects in the Grm1(crv4/crv4) mice.

Alterations in striatal dopamine catabolism precede loss of substantia nigra neurons in a mouse model of Juvenile Neuronal Ceroid Lipofuscinosis

PubMed Central

Weimer, Jill M.; Benedict, Jared W.; Elshatory, Yasser M.; Short, Douglas W.; Ramirez-Montealegre, Denia; Ryan, Deborah A.; Alexander, Noreen A.; Federoff, Howard J.; Cooper, Jonathan D.; Pearce, David A.

2016-01-01

Batten disease, or juvenile neuronal ceroid lipofuscinosis (JNCL), results from mutations in the CLN3 gene. This disorder presents clinically around the age of five years with visual deficits progressing to include seizures, cognitive impairment, motor deterioration, hallucinations, and premature death by the third to forth decade of life. The motor deficits include coordination and gait abnormalities, myoclonic jerks, inability to initiate movements, and spasticity. Previous work from our laboratory has identified an early reduction in catechol-O-methyltransferase (COMT), an enzyme responsible for the efficient degradation of dopamine. Alterations in the kinetics of dopamine metabolism could cause the accumulation of undegraded or unsequestered dopamine leading to the formation of toxic dopamine intermediates. We report an imbalance in the catabolism of dopamine in three month Cln3-/- mice persisting through nine months of age that may be causal to oxidative damage within the striatum at nine months of age. Combined with the previously reported inflammatory changes and loss of post-synaptic D1α receptors, this could facilitate cell loss in striatal projection regions and underlie a general locomotion deficit that becomes apparent at twelve months of age in Cln3-/- mice. This study provides evidence for early changes in the kinetics of COMT in the Cln3-/- mouse striatum, affecting the turnover of dopamine, likely leading to neuron loss and motor deficits. These data provide novel insights into the basis of motor deficits in JNCL and how alterations in dopamine catabolism may result in oxidative damage and localized neuronal loss in this disorder. PMID:17617387

Mouse Myosin-19 Is a Plus-end-directed, High-duty Ratio Molecular Motor*

PubMed Central

Lu, Zekuan; Ma, Xiao-Nan; Zhang, Hai-Man; Ji, Huan-Hong; Ding, Hao; Zhang, Jie; Luo, Dan; Sun, Yujie; Li, Xiang-dong

2014-01-01

Class XIX myosin (Myo19) is a vertebrate-specific unconventional myosin, responsible for the transport of mitochondria. To characterize biochemical properties of Myo19, we prepared recombinant mouse Myo19-truncated constructs containing the motor domain and the IQ motifs using the baculovirus/Sf9 expression system. We identified regulatory light chain (RLC) of smooth muscle/non-muscle myosin-2 as the light chain of Myo19. The actin-activated ATPase activity and the actin-gliding velocity of Myo19-truncated constructs were about one-third and one-sixth as those of myosin-5a, respectively. The apparent affinity of Myo19 to actin was about the same as that of myosin-5a. The RLCs bound to Myo19 could be phosphorylated by myosin light chain kinase, but this phosphorylation had little effect on the actin-activated ATPase activity and the actin-gliding activity of Myo19-truncated constructs. Using dual fluorescence-labeled actin filaments, we determined that Myo19 is a plus-end-directed molecular motor. We found that, similar to that of the high-duty ratio myosin, such as myosin-5a, ADP release rate was comparable with the maximal actin-activated ATPase activity of Myo19, indicating that ADP release is a rate-limiting step for the ATPase cycle of acto-Myo19. ADP strongly inhibited the actin-activated ATPase activity and actin-gliding activity of Myo19-truncated constructs. Based on the above results, we concluded that Myo19 is a high-duty ratio molecular motor moving to the plus-end of the actin filament. PMID:24825904

Protective effects of butyrate-based compounds on a mouse model for spinal muscular atrophy.

PubMed

Butchbach, Matthew E R; Lumpkin, Casey J; Harris, Ashlee W; Saieva, Luciano; Edwards, Jonathan D; Workman, Eileen; Simard, Louise R; Pellizzoni, Livio; Burghes, Arthur H M

2016-05-01

Proximal spinal muscular atrophy (SMA) is a childhood-onset degenerative disease resulting from the selective loss of motor neurons in the spinal cord. SMA is caused by the loss of SMN1 (survival motor neuron 1) but retention of SMN2. The number of copies of SMN2 modifies disease severity in SMA patients as well as in mouse models, making SMN2 a target for therapeutics development. Sodium butyrate (BA) and its analog (4PBA) have been shown to increase SMN2 expression in SMA cultured cells. In this study, we examined the effects of BA, 4PBA as well as two BA prodrugs-glyceryl tributyrate (BA3G) and VX563-on the phenotype of SMNΔ7 SMA mice. Treatment with 4PBA, BA3G and VX563 but not BA beginning at PND04 significantly improved the lifespan and delayed disease end stage, with administration of VX563 also improving the growth rate of these mice. 4PBA and VX563 improved the motor phenotype of SMNΔ7 SMA mice and prevented spinal motor neuron loss. Interestingly, neither 4PBA nor VX563 had an effect on SMN expression in the spinal cords of treated SMNΔ7 SMA mice; however, they inhibited histone deacetylase (HDAC) activity and restored the normal phosphorylation states of Akt and glycogen synthase kinase 3β, both of which are altered by SMN deficiency in vivo. These observations show that BA-based compounds with favorable pharmacokinetics ameliorate SMA pathology possibly by modulating HDAC and Akt signaling. Copyright © 2016 Elsevier Inc. All rights reserved.

Congenital Bone Fractures in Spinal Muscular Atrophy: Functional Role for SMN Protein in Bone Remodeling

PubMed Central

Shanmugarajan, Srinivasan; Swoboda, Kathryn J.; Iannaccone, Susan T.; Ries, William L.; Maria, Bernard L.; Reddy, Sakamuri V.

2009-01-01

Spinal muscular atrophy is the second most common fatal childhood disorder. Core clinical features include muscle weakness caused by degenerating lower motor neurons and a high incidence of bone fractures and hypercalcemia. Fractures further compromise quality of life by progression of joint contractures or additional loss of motor function. Recent observations suggest that bone disease in spinal muscular atrophy may not be attributed entirely to lower motor neuron degeneration. The presence of the spinal muscular atrophy disease-determining survival motor neuron gene (SMN), SMN expression, and differential splicing in bone-resorbing osteoclasts was recently discovered. Its ubiquitous expression and the differential expression of splice variants suggest that SMN has specific roles in bone cell function. SMN protein also interacts with osteoclast stimulatory factor. Mouse models of human spinal muscular atrophy disease suggest a potential role of SMN protein in skeletal development. Dual energy x-ray absorptiometry analysis demonstrated a substantial decrease in total bone area and poorly developed caudal vertebra in the mouse model. These mice also had pelvic bone fractures. Studies delineating SMN signaling mechanisms and gene transcription in a cell-specific manner will provide important molecular insights into the pathogenesis of bone disease in children with spinal muscular atrophy. Moreover, understanding bone remodeling in spinal muscular atrophy may lead to novel therapeutic approaches to enhance skeletal health and quality of life. This article reviews the skeletal complications associated with spinal muscular atrophy and describes a functional role for SMN protein in osteoclast development and bone resorption activity. PMID:17761651

Reduced Activity of AMP-Activated Protein Kinase Protects against Genetic Models of Motor Neuron Disease

PubMed Central

Lim, M. A.; Selak, M. A.; Xiang, Z.; Krainc, D.; Neve, R. L.; Kraemer, B. C.; Watts, J. L.

2012-01-01

A growing body of research indicates that amyotrophic lateral sclerosis (ALS) patients and mouse models of ALS exhibit metabolic dysfunction. A subpopulation of ALS patients possesses higher levels of resting energy expenditure and lower fat-free mass compared to healthy controls. Similarly, two mutant copper zinc superoxide dismutase 1 (mSOD1) mouse models of familial ALS possess a hypermetabolic phenotype. The pathophysiological relevance of the bioenergetic defects observed in ALS remains largely elusive. AMP-activated protein kinase (AMPK) is a key sensor of cellular energy status and thus might be activated in various models of ALS. Here, we report that AMPK activity is increased in spinal cord cultures expressing mSOD1, as well as in spinal cord lysates from mSOD1 mice. Reducing AMPK activity either pharmacologically or genetically prevents mSOD1-induced motor neuron death in vitro. To investigate the role of AMPK in vivo, we used Caenorhabditis elegans models of motor neuron disease. C. elegans engineered to express human mSOD1 (G85R) in neurons develops locomotor dysfunction and severe fecundity defects when compared to transgenic worms expressing human wild-type SOD1. Genetic reduction of aak-2, the ortholog of the AMPK α2 catalytic subunit in nematodes, improved locomotor behavior and fecundity in G85R animals. Similar observations were made with nematodes engineered to express mutant tat-activating regulatory (TAR) DNA-binding protein of 43 kDa molecular weight. Altogether, these data suggest that bioenergetic abnormalities are likely to be pathophysiologically relevant to motor neuron disease. PMID:22262909

Protective Effects of Butyrate-based Compounds on a Mouse Model for Spinal Muscular Atrophy

PubMed Central

Butchbach, Matthew E. R.; Lumpkin, Casey J.; Harris, Ashlee W.; Saieva, Luciano; Edwards, Jonathan D.; Workman, Eileen; Simard, Louise R.; Pellizzoni, Livio; Burghes, Arthur H. M.

2016-01-01

Proximal spinal muscular atrophy (SMA) is a childhood-onset degenerative disease resulting from the selective loss of motor neurons in the spinal cord. SMA is caused by the loss of SMN1 (survival motor neuron 1) but retention of SMN2. The number of copies of SMN2 modifies disease severity in SMA patients as well as in mouse models, making SMN2 a target for therapeutics development. Sodium butyrate (BA) and its analogue (4PBA) have been shown to increase SMN2 expression in SMA cultured cells. In this study, we examined the effects of BA, 4PBA as well as two BA prodrugs—glyceryl tributyrate (BA3G) and VX563—on the phenotype of SMNΔ7 SMA mice. Treatment with 4PBA, BA3G and VX563 but not BA beginning at PND04 significantly improved the lifespan and delayed disease end stage, with administration of VX563 also improving the growth rate of these mice. 4PBA and VX563 improved the motor phenotype of SMNΔ7 SMA mice and prevented spinal motor neuron loss. Interestingly, neither 4PBA nor VX563 had an effect on SMN expression in the spinal cords of treated SMNΔ7 SMA mice; however, they inhibited histone deacetylase (HDAC) activity and restored the normal phosphorylation states of Akt and glycogen synthase kinase 3β, both of which are altered by SMN deficiency in vivo. These observations show that BA-based compounds with favourable pharmacokinetics ameliorate SMA pathology possibly by modulating HDAC and Akt signaling. PMID:26892876

TOP VIEW OF UPPER TRAM TERMINAL, PRIMARY ORE BIN, AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

TOP VIEW OF UPPER TRAM TERMINAL, PRIMARY ORE BIN, AND ORE CHUTE,LOOKING SOUTHWEST. TRAM MACHINERY AND GEARS ARE AT LOWER CENTER. A SMALL ELECTRIC MOTOR AT THE REAR LEFT OF THE TERMINAL PROBABLY WAS ADDED AFTER THE ORIGINAL CONSTRUCTION. THE MOVING CABLE OF THE TRAM WAS DRIVEN BY THESE GEARS AND THE LARGE WHEEL UNDERNEATH (SEE CA-291-31 FOR DETAIL). EMPTY TRAM BUCKETS CAME IN FROM THE LEFT, SWINGING AROUND TO THE CHUTES FROM THE ORE BIN TO BE LOADED FOR THE TRIP DOWN TO THE MILL (SEE CA-291-35 FOR DETAIL). THE BREAK OVER TOWER CAN BE SEEN IN THE DISTANCE AT TOP LEFT. THE SUPPORT TOWER BETWEEN THE UPPER TERMINAL AND THE BREAK OVER TOWER IS COLLAPSED. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

Paired associative stimulation induces change in presynaptic inhibition of Ia terminals in wrist flexors in humans.

PubMed

Lamy, Jean-Charles; Russmann, Heike; Shamim, Ejaz A; Meunier, Sabine; Hallett, Mark

2010-08-01

Enhancements in the strength of corticospinal projections to muscles are induced in conscious humans by paired associative stimulation (PAS) to the motor cortex. Although most of the previous studies support the hypothesis that the increase of the amplitude of motor evoked potentials (MEPs) by PAS involves long-term potentiation (LTP)-like mechanism in cortical synapses, changes in spinal excitability after PAS have been reported, suggestive of parallel modifications in both cortical and spinal excitability. In a first series of experiments (experiment 1), we confirmed that both flexor carpi radialis (FCR) MEPs and FCR H reflex recruitment curves are enhanced by PAS. To elucidate the mechanism responsible for this change in the H reflex amplitude, we tested, using the same subjects, the hypothesis that enhanced H reflexes are caused by a down-regulation of the efficacy of mechanisms controlling Ia afferent discharge, including presynaptic Ia inhibition and postactivation depression. To address this question, amounts of both presynaptic Ia inhibition of FCR Ia terminals (D1 and D2 inhibitions methods; experiment 2) and postactivation depression (experiment 3) were determined before and after PAS. Results showed that PAS induces a significant decrease of presynaptic Ia inhibition of FCR terminals, which was concomitant with the facilitation of the H reflex. Postactivation depression was unaffected by PAS. It is argued that enhancement of segmental excitation by PAS relies on a selective effect of PAS on the interneurons controlling presynaptic inhibition of Ia terminals.

Mesodermal and neuronal retinoids regulate the induction and maintenance of limb innervating spinal motor neurons.

PubMed

Ji, Sheng-Jian; Zhuang, BinQuan; Falco, Crystal; Schneider, André; Schuster-Gossler, Karin; Gossler, Achim; Sockanathan, Shanthini

2006-09-01

During embryonic development, the generation, diversification and maintenance of spinal motor neurons depend upon extrinsic signals that are tightly regulated. Retinoic acid (RA) is necessary for specifying the fates of forelimb-innervating motor neurons of the Lateral Motor Column (LMC), and the specification of LMC neurons into medial and lateral subtypes. Previous studies implicate motor neurons as the relevant source of RA for specifying lateral LMC fates at forelimb levels. However, at the time of LMC diversification, a significant amount of retinoids in the spinal cord originates from the adjacent paraxial mesoderm. Here we employ mouse genetics to show that RA derived from the paraxial mesoderm is required for lateral LMC induction at forelimb and hindlimb levels, demonstrating that mesodermally synthesized RA functions as a second source of signals to specify lateral LMC identity. Furthermore, reduced RA levels in postmitotic motor neurons result in a decrease of medial and lateral LMC neurons, and abnormal axonal projections in the limb; invoking additional roles for neuronally synthesized RA in motor neuron maintenance and survival. These findings suggest that during embryogenesis, mesodermal and neuronal retinoids act coordinately to establish and maintain appropriate cohorts of spinal motor neurons that innervate target muscles in the limb.

Peptides mimicking viral proteins of porcine circovirus type 2 were profiled by the spectrum of mouse anti-PCV2 antibodies.

PubMed

Hung, Ling-Chu; Yang, Cheng-Yao; Cheng, Ivan-Chen

2017-05-15

Porcine circovirus 2 (PCV2) is a small, non-enveloped DNA virus causing swine lymphocyte depletion and severe impact on the swine industry. The aim of this study was to evaluate the antigenicity and immunogenicity of specific peptides, and seeking the potential candidate of PCV2 peptide-based vaccine. It's initiating from peptides reacting with PCV2-infected pig sera and peptide-immunized mouse sera. The data showed that the sera from PCV2-infected pigs could react with the N-terminal (C1), middle region (C2), and C-terminal peptide (C3) of PCV2 capsid protein (CP), ORF3 protein (N1), ORF6 protein (N2) and ORF9 protein (N3). This study demonstrated that anti-PCV2 mouse antisera could be generated by specific synthetic peptides (C3 and N2) and recognized PCV2 viral protein. We found that the tertiary or linear form C-terminal sequence (C3) of PCV2 capsid peptide only appeared a local distribution in the nucleus of PCV2-infected PK cells, virus-like particles of PCV2 major appeared a local distribution in the cytoplasm, and ORF 6 protein of PCV2 were shown unusually in cytoplasm. Furthermore, most residues of the C1 and the C3 were presented on the surface of PCV2 CP, in the view of 3-D structure of the CP. Our data demonstrated that PCV2-infected pigs had higher OD 405 value of anti-C3 IgG on Day 1, Month 3 and Month 6 than in Month 1. These pigs had higher anti-C3 IgM level in Month 3 and Month 6 than on Day 1 (P < 0.01). We demonstrated that the key peptide (C3) mimic the C-terminal of PCV2 capsid protein which were capable of inducing antibodies. The specific antibody against the C3 were confirmed as the serological marker in PCV2-infected pigs.

Zincergic innervation from the anterior olfactory nucleus to the olfactory bulb displays plastic responses after mitral cell loss.

PubMed

Airado, Carmen; Gómez, Carmela; Recio, Javier S; Baltanás, Fernando C; Weruaga, Eduardo; Alonso, José R

2008-12-01

Zinc ions are selectively accumulated in certain neurons (zinc-enriched neurons). The mouse olfactory bulb is richly innervated by zinc-enriched terminals. Here, the plasticity of the zincergic system was studied in the olfactory bulb of the Purkinje Cell Degeneration mutant mouse, an animal with specific postnatal neurodegeneration of the main projection neurons of the olfactory bulb. The analysis focused particularly on the anterior olfactory nucleus since most centrifugal afferents coming to the olfactory bulb arise from this structure. Zinc-enriched terminals in the olfactory bulb and zinc-enriched somata in the anterior olfactory nucleus were visualized after selenite injections. Immunohistochemistry against the vesicular zinc transporter was also carried out to confirm the distribution pattern of zinc-enriched terminals in the olfactory bulb. The mutant mice showed a clear reorganization of zincergic centrifugal projections from the anterior olfactory nucleus to the olfactory bulb. First, all zincergic contralateral neurons projecting to the olfactory bulb were absent in the mutant mice. Second, a significant increase in the number of stained somata was detected in the ipsilateral anterior olfactory nucleus. Since no noticeable changes were observed in the zinc-enriched terminals in the olfactory bulb, it is conceivable that mitral cell loss could induce a reorganization of zinc-enriched projections coming from the anterior olfactory nucleus, probably directed at balancing the global zincergic centrifugal modulation. These results show that zincergic anterior olfactory nucleus cells projecting to the olfactory bulb undergo plastic changes to adapt to the loss of mitral cells in the olfactory bulb of Purkinje Cell Degeneration mutant mice.

Abundant pyroglutamate-modified ABri and ADan peptides in extracellular and vascular amyloid deposits in familial British and Danish dementias.

PubMed

Saul, Anika; Lashley, Tammaryn; Revesz, Tamas; Holton, Janice; Ghiso, Jorge A; Coomaraswamy, Janaky; Wirths, Oliver

2013-05-01

Familial British and familial Danish dementia (FDD) are progressive neurodegenerative disorders characterized by cerebral deposition of the amyloidogenic peptides ABri and ADan, respectively. These amyloid peptides start with an N-terminal glutamate residue, which can be posttranslationally converted into a pyroglutamate (pGlu) modified form, a mechanism which has been extensively described to be relevant for amyloid-beta (Aβ) peptides in Alzheimer's disease. Like pGlu-Aβ peptides, pGlu-ABri peptides have an increased aggregation propensity and show higher toxicity on human neuroblastoma cells as their nonmodified counterparts. We have generated novel N-terminal specific antibodies detecting the pGlu-modified forms of ABri and ADan peptides. With these antibodies we were able to identify abundant extracellular amyloid plaques, vascular, and parenchymal deposits in human familial British dementia and FDD brain tissue, and in a mouse model for FDD. Double-stainings using C-terminal specific antibodies in human samples revealed that highly aggregated pGlu-ABri and pGlu-ADan peptides are mainly present in plaque cores and central vascular deposits, leading to the assumption that these peptides have seeding properties. Furthermore, in an FDD-mouse model ADan peptides were detected in presynaptic terminals of the hippocampus where they might contribute to impaired synaptic transmission. These similarities of ABri and ADan to Aβ in Alzheimer's disease suggest that the posttranslational pGlu-modification of amyloid peptides might represent a general pathological mechanism leading to increased aggregation and toxicity in these forms of degenerative dementias. Copyright © 2013 Elsevier Inc. All rights reserved.

Abundant pyroglutamate-modified ABri and ADan peptides in extracellular and vascular amyloid deposits in familial British and Danish dementias

PubMed Central

Saul, Anika; Lashley, Tammaryn; Revesz, Tamas; Holton, Janice; Ghiso, Jorge A.; Coomaraswamy, Janaky; Wirths, Oliver

2013-01-01

Familial British (FBD) and familial Danish dementia (FDD) are progressive neurodegenerative disorders characterized by cerebral deposition of the amyloidogenic peptides ABri and ADan. These amyloid peptides start with an N-terminal glutamate residue, which can be posttranslationally converted into a pyroglutamate (pGlu-) modified form, a mechanism which has been extensively described to be relevant for Aβ peptides in Alzheimer’s disease (AD). Like pGlu-Aβ peptides, pGlu-ABri peptides have an increased aggregation propensity and show higher toxicity on human neuroblastoma cells as their non-modified counterparts. We have generated novel N-terminal specific antibodies detecting the pGlu-modified forms of ABri and ADan peptides. With these antibodies we were able to identify abundant extracellular amyloid plaques, vascular and parenchymal deposits in human FBD and FDD brain tissue, as well as in a mouse model for FDD. Double-stainings using C-terminal specific antibodies in human samples revealed that highly aggregated pGlu-ABri and pGlu-ADan peptides are mainly present in plaque cores and central vascular deposits, leading to the assumption that these peptides have seeding properties. Furthermore, in an FDD-mouse model ADan peptides were detected in pre-synaptic terminals of the hippocampus where they might contribute to impaired synaptic transmission. These similarities of ABri and ADan to Aβ in AD suggest that the posttranslational pGlu-modification of amyloid peptides might represent a general pathological mechanism leading to increased aggregation and toxicity in these forms of degenerative dementias. PMID:23261769

VAChT overexpression increases acetylcholine at the synaptic cleft and accelerates aging of neuromuscular junctions.

PubMed

Sugita, Satoshi; Fleming, Leland L; Wood, Caleb; Vaughan, Sydney K; Gomes, Matheus P S M; Camargo, Wallace; Naves, Ligia A; Prado, Vania F; Prado, Marco A M; Guatimosim, Cristina; Valdez, Gregorio

2016-01-01

Cholinergic dysfunction occurs during aging and in a variety of diseases, including amyotrophic lateral sclerosis (ALS). However, it remains unknown whether changes in cholinergic transmission contributes to age- and disease-related degeneration of the motor system. Here we investigated the effect of moderately increasing levels of synaptic acetylcholine (ACh) on the neuromuscular junction (NMJ), muscle fibers, and motor neurons during development and aging and in a mouse model for amyotrophic lateral sclerosis (ALS). Chat-ChR2-EYFP (VAChT Hyp ) mice containing multiple copies of the vesicular acetylcholine transporter (VAChT), mutant superoxide dismutase 1 (SOD1 G93A ), and Chat-IRES-Cre and tdTomato transgenic mice were used in this study. NMJs, muscle fibers, and α-motor neurons' somata and their axons were examined using a light microscope. Transcripts for select genes in muscles and spinal cords were assessed using real-time quantitative PCR. Motor function tests were carried out using an inverted wire mesh and a rotarod. Electrophysiological recordings were collected to examine miniature endplate potentials (MEPP) in muscles. We show that VAChT is elevated in the spinal cord and at NMJs of VAChT Hyp mice. We also show that the amplitude of MEPPs is significantly higher in VAChT Hyp muscles, indicating that more ACh is loaded into synaptic vesicles and released into the synaptic cleft at NMJs of VAChT Hyp mice compared to control mice. While the development of NMJs was not affected in VAChT Hyp mice, NMJs prematurely acquired age-related structural alterations in adult VAChT Hyp mice. These structural changes at NMJs were accompanied by motor deficits in VAChT Hyp mice. However, cellular features of muscle fibers and levels of molecules with critical functions at the NMJ and in muscle fibers were largely unchanged in VAChT Hyp mice. In the SOD1 G93A mouse model for ALS, increasing synaptic ACh accelerated degeneration of NMJs caused motor deficits and resulted in premature death specifically in male mice. The data presented in this manuscript demonstrate that increasing levels of ACh at the synaptic cleft promote degeneration of adult NMJs, contributing to age- and disease-related motor deficits. We thus propose that maintaining normal cholinergic signaling in muscles will slow degeneration of NMJs and attenuate loss of motor function caused by aging and neuromuscular diseases.

Peptidomics of Cpefat/fat mouse brain regions: Implications for neuropeptide processing

PubMed Central

Zhang, Xin; Che, Fa-Yun; Berezniuk, Iryna; Sonmez, Kemal; Toll, Lawrence; Fricker, Lloyd D.

2009-01-01

SUMMARY Quantitative peptidomics was used to compare levels of peptides in wild type and Cpefat/fat mice, which lack carboxypeptidase E (CPE) activity due to a point mutation. Six different brain regions were analyzed: amygdala, hippocampus, hypothalamus, prefrontal cortex, striatum, and thalamus. Altogether, 111 neuropeptides or other peptides derived from secretory pathway proteins were identified in wild type mouse brain extracts by tandem mass spectrometry, and another 47 peptides were tentatively identified based on mass and other criteria. Most secretory pathway peptides were much lower in Cpefat/fat mouse brain, relative to wild type mouse brain, indicating that CPE plays a major role in their biosynthesis. Other peptides were only partially reduced in the Cpefat/fat mice, indicating that another enzyme (presumably carboxypeptidase D) contributes to their biosynthesis. Approximately 10% of the secretory pathway peptides were present in the Cpefat/fat mouse brain at levels similar to those in wild type mouse brain. Many peptides were greatly elevated in the Cpefat/fat mice; these peptide processing intermediates with C-terminal Lys and/or Arg were generally not detectable in wild type mice. Taken together, these results indicate that CPE contributes, either directly or indirectly, to the production of the majority of neuropeptides. PMID:19014391

Survival motor neuron protein in motor neurons determines synaptic integrity in spinal muscular atrophy.

PubMed

Martinez, Tara L; Kong, Lingling; Wang, Xueyong; Osborne, Melissa A; Crowder, Melissa E; Van Meerbeke, James P; Xu, Xixi; Davis, Crystal; Wooley, Joe; Goldhamer, David J; Lutz, Cathleen M; Rich, Mark M; Sumner, Charlotte J

2012-06-20

The inherited motor neuron disease spinal muscular atrophy (SMA) is caused by deficient expression of survival motor neuron (SMN) protein and results in severe muscle weakness. In SMA mice, synaptic dysfunction of both neuromuscular junctions (NMJs) and central sensorimotor synapses precedes motor neuron cell death. To address whether this synaptic dysfunction is due to SMN deficiency in motor neurons, muscle, or both, we generated three lines of conditional SMA mice with tissue-specific increases in SMN expression. All three lines of mice showed increased survival, weights, and improved motor behavior. While increased SMN expression in motor neurons prevented synaptic dysfunction at the NMJ and restored motor neuron somal synapses, increased SMN expression in muscle did not affect synaptic function although it did improve myofiber size. Together these data indicate that both peripheral and central synaptic integrity are dependent on motor neurons in SMA, but SMN may have variable roles in the maintenance of these different synapses. At the NMJ, it functions at the presynaptic terminal in a cell-autonomous fashion, but may be necessary for retrograde trophic signaling to presynaptic inputs onto motor neurons. Importantly, SMN also appears to function in muscle growth and/or maintenance independent of motor neurons. Our data suggest that SMN plays distinct roles in muscle, NMJs, and motor neuron somal synapses and that restored function of SMN at all three sites will be necessary for full recovery of muscle power.

75 FR 81637 - Endangered and Threatened Wildlife and Plants; Notice of Availability of the St. Andrew Beach...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-28

... activities associated with development and tourism that weaken and encroach on the dune ecosystem... minimum, address the following: (a) Impact of commercial/residential development and recreational use, including that of pedestrians and motorized vehicles, to beach mouse habitat. (b) Impact of shoreline...

A multivariate prediction model for Rho-dependent termination of transcription.

PubMed

Nadiras, Cédric; Eveno, Eric; Schwartz, Annie; Figueroa-Bossi, Nara; Boudvillain, Marc

2018-06-21

Bacterial transcription termination proceeds via two main mechanisms triggered either by simple, well-conserved (intrinsic) nucleic acid motifs or by the motor protein Rho. Although bacterial genomes can harbor hundreds of termination signals of either type, only intrinsic terminators are reliably predicted. Computational tools to detect the more complex and diversiform Rho-dependent terminators are lacking. To tackle this issue, we devised a prediction method based on Orthogonal Projections to Latent Structures Discriminant Analysis [OPLS-DA] of a large set of in vitro termination data. Using previously uncharacterized genomic sequences for biochemical evaluation and OPLS-DA, we identified new Rho-dependent signals and quantitative sequence descriptors with significant predictive value. Most relevant descriptors specify features of transcript C>G skewness, secondary structure, and richness in regularly-spaced 5'CC/UC dinucleotides that are consistent with known principles for Rho-RNA interaction. Descriptors collectively warrant OPLS-DA predictions of Rho-dependent termination with a ∼85% success rate. Scanning of the Escherichia coli genome with the OPLS-DA model identifies significantly more termination-competent regions than anticipated from transcriptomics and predicts that regions intrinsically refractory to Rho are primarily located in open reading frames. Altogether, this work delineates features important for Rho activity and describes the first method able to predict Rho-dependent terminators in bacterial genomes.

49 CFR 372.221 - Twin Cities.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 5 2013-10-01 2013-10-01 false Twin Cities. 372.221 Section 372.221 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY... ZONES, AND TERMINAL AREAS Commercial Zones § 372.221 Twin Cities. For the purpose of determining...

49 CFR 372.221 - Twin Cities.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 5 2012-10-01 2012-10-01 false Twin Cities. 372.221 Section 372.221 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY... ZONES, AND TERMINAL AREAS Commercial Zones § 372.221 Twin Cities. For the purpose of determining...

49 CFR 372.221 - Twin Cities.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 5 2014-10-01 2014-10-01 false Twin Cities. 372.221 Section 372.221 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY... ZONES, AND TERMINAL AREAS Commercial Zones § 372.221 Twin Cities. For the purpose of determining...

78 FR 35931 - Granting of Request for Early Termination of the Waiting Period Under the Premerger Notification...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-14

..., Inc.; Sage Parent Company, Inc.; Herff Jones, Inc. 20130875 G Eastman Kodak Company; Eastman Kodak Company; Eastman Kodak Company. 05/28/2013 20130871 G Elon Musk; Tesla Motors, Inc.; Elon Musk. 05/29/2013...