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121.
Evaluation of motor coordination and motor learning in mice remains a challenge as many factors may interact with the different tests used. Among these factors, genetic background has been reported to be a major determinant of mice performances in motor coordination tests. However, it is not known if the strain dependence of motor coordination and motor learning remains constant through life. In order to assess this point, we tested during 5 days male and female mice of three different strains (NMRI, C57BL/6J, and C57BL/6J x 129OlaHsd) in runway, rotarod, and thin rod tests at juvenile (first day of testing = postnatal day 19) and adult (3 months) age. We found a strong strain effect on motor performances and motor learning at juvenile age (C57BL/6J performing more poorly than the two other strains), whatever the tests used. Interestingly, the C57BL/6J mice were the best performing mice at the adult age. These strain rankings were observed either in male and female groups. These results demonstrate that the strain determinant on mice performances and motor learning is highly age dependent. 相似文献
122.
Jordi Bonaventura Gemma Navarro Verònica Casadó-Anguera Karima Azdad William Rea Estefanía Moreno Marc Brugarolas Josefa Mallol Enric I. Canela Carme Lluís Antoni Cortés Nora D. Volkow Serge N. Schiffmann Sergi Ferré Vicent Casadó 《Proceedings of the National Academy of Sciences of the United States of America》2015,112(27):E3609-E3618
Adenosine A2A receptor (A2AR)-dopamine D2 receptor (D2R) heteromers are key modulators of striatal neuronal function. It has been suggested that the psychostimulant effects of caffeine depend on its ability to block an allosteric modulation within the A2AR-D2R heteromer, by which adenosine decreases the affinity and intrinsic efficacy of dopamine at the D2R. We describe novel unsuspected allosteric mechanisms within the heteromer by which not only A2AR agonists, but also A2AR antagonists, decrease the affinity and intrinsic efficacy of D2R agonists and the affinity of D2R antagonists. Strikingly, these allosteric modulations disappear on agonist and antagonist coadministration. This can be explained by a model that considers A2AR-D2R heteromers as heterotetramers, constituted by A2AR and D2R homodimers, as demonstrated by experiments with bioluminescence resonance energy transfer and bimolecular fluorescence and bioluminescence complementation. As predicted by the model, high concentrations of A2AR antagonists behaved as A2AR agonists and decreased D2R function in the brain.Most evidence indicates that G protein-coupled receptors (GPCRs) form homodimers and heteromers. Homodimers seem to be a predominant species, and oligomeric entities can be viewed as multiples of dimers (1). It has been proposed that GPCR heteromers are constituted mainly by heteromers of homodimers (1, 2). Allosteric mechanisms determine a multiplicity of unique pharmacologic properties of GPCR homodimers and heteromers (1, 3). First, binding of a ligand to one of the receptors in the heteromer can modify the affinity of ligands for the other receptor (1, 3, 4). The most widely reproduced allosteric modulation of ligand-binding properties in a GPCR heteromer is the ability of adenosine A2A receptor (A2AR) agonists to decrease the affinity of dopamine D2 receptor (D2R) agonists in the A2AR-D2R heteromer (5). A2AR-D2R heteromers have been revealed both in transfected cells (6, 7), striatal neurons in culture (6, 8) and in situ, in mammalian striatum (9, 10), where they play an important role in the modulation of GABAergic striatopallidal neuronal function (9, 11).In addition to ligand-binding properties, unique properties for each GPCR oligomer emerge in relation to the varying intrinsic efficacy of ligands for different signaling pathways (1–3). Intrinsic efficacy refers to the power of the agonist to induce a functional response, independent of its affinity for the receptor. Thus, allosteric modulation of an agonist can potentially involve changes in affinity and/or intrinsic efficacy (1, 3). This principle can be observed in the A2AR-D2R heteromer, where a decrease in D2R agonist affinity cannot alone explain the ability of an A2AR agonist to abolish the decreased excitability of GABAergic striatopallidal neurons induced by high concentration of a D2R agonist (9), which should overcome the decrease in affinity. Furthermore, a differential effect of allosteric modulations of different agonist-mediated signaling responses (i.e., functional selectivity) can occur within GPCR heteromers (1, 2, 8). Again, the A2AR-D2R heteromer provides a valuable example. A recent study has shown that different levels of intracellular Ca2+ exert different modulations of A2AR-D2R heteromer signaling (8). This depends on the ability of low and high Ca2+ to promote a selective interaction of the heteromer with different Ca2+-binding proteins, which differentially modulate allosteric interactions in the heteromer (8).It has been hypothesized that the allosteric interactions between A2AR and D2R agonists within the A2AR-D2R heteromer provide a mechanism responsible not only for the depressant effects of A2AR agonists, but also for the psychostimulant effects of adenosine A2AR antagonists and the nonselective adenosine receptor antagonist caffeine (9, 11, 12), with implications for several neuropsychiatric disorders (13). In fact, the same mechanism has provided the rationale for the use of A2AR antagonists in patients with Parkinson’s disease (13, 14). The initial aim of the present study was to study in detail the ability of caffeine to counteract allosteric modulations between A2AR and D2R agonists (affinity and intrinsic efficacy) within the A2AR-D2R heteromer. Unexpectedly, when performing control radioligand-binding experiments, not only an A2AR agonist, but also caffeine, significantly decreased D2R agonist binding. However, when coadministered, the A2AR agonist and caffeine co-counteracted their ability to modulate D2R agonist binding. By exploring the molecular mechanisms behind these apparent inconsistencies, the present study provides new insight into the quaternary structure and function of A2AR-D2R heteromers. 相似文献
123.
A. Vellodi A. Tylki-Szymanska E. H. Davies E. Kolodny B. Bembi T. Collin-Histed E. Mengel A. Erikson R. Schiffmann 《Journal of inherited metabolic disease》2009,32(5):660-664
The original guidelines drawn up for the management of the neuronopathic forms of Gaucher disease were felt to be in need
of revision; in particular, the role of high-dose enzyme replacement therapy (120 IU/kg of body weight every 2 weeks) in stabilizing
neurological disease. The existing published evidence was analysed; it was concluded that it did not support the role of high-dose
ERT, although this might be required to treat severe visceral disease. 相似文献
124.
Quantitative analysis of epidermal innervation in Fabry disease 总被引:6,自引:0,他引:6
Scott LJ Griffin JW Luciano C Barton NW Banerjee T Crawford T McArthur JC Tournay A Schiffmann R 《Neurology》1999,52(6):1249-1254
OBJECTIVE: To use skin biopsy specimens to quantitate the cutaneous innervation density of Fabry patients who had preserved renal function. BACKGROUND: The small fiber neuropathy of Fabry disease is difficult to detect and quantitate by conventional methods. Because this neuropathy is a common characteristic of Fabry disease, quantitating changes in this parameter would be helpful in demonstrating the effectiveness of enzyme or gene replacement therapy. METHODS: Patients underwent skin biopsy at the thigh and foot. Innervation density was determined by counting free nerve endings in the epidermis. These data were compared with nerve conduction studies, and in selected patients, fiber quantitation of sural nerve biopsy specimens. RESULTS: The Fabry patients had normal results of nerve conduction studies and large fiber quantitation by sural nerve biopsy. However, the involvement of small cutaneous fibers in these patients was easily demonstrable and quantifiable by skin biopsy. All patients showed severe loss of intraepidermal innervation at the ankle, but fiber loss at the distal thigh was proportionately less severe. CONCLUSIONS: The nerve damage in Fabry patients with preserved renal function involves exclusively small myelinated and unmyelinated fibers, and skin biopsy is a useful in detecting and quantitating such damage. Comparison of cutaneous innervation density with quantitation of sural nerve biopsy specimens demonstrated that skin biopsy specimens were as sensitive in detecting the presence of neuropathy as were the nerve specimens. It is speculated that analysis of cutaneous innervation may provide a useful marker of the nervous system's response to specific therapy for Fabry disease. 相似文献
125.
Timothy?ClairEmail author Eunjin?Koh Malgorzata?Ptaszynska Russell?W?Bandle Lance?A?Liotta Elliott?Schiffmann Mary?L?Stracke 《Lipids in health and disease》2005,4(1):5
Background
Autotaxin (ATX, NPP-2), originally purified as a potent tumor cell motility factor, is now known to be the long-sought plasma lysophospholipase D (LPLD). The integrity of the enzymatic active site, including three crucial histidine moieties, is required for motility stimulation, as well as LPLD and 5'nucleotide phosphodiesterase (PDE) activities. Except for relatively non-specific chelation agents, there are no known inhibitors of the ATX LPLD activity. 相似文献126.
Fabry disease is associated with increased risk of premature stroke and presumptive ischemic cerebral lesions. In 57 consecutive patients, 35% of whom had lesions on brain MRI, the authors found that genotypes of polymorphisms G-174C of interleukin-6, G894T of endothelial nitric oxide synthase, factor V G1691A mutation, and the A-13G and G79A of protein Z were all significantly associated with cerebral lesions. These findings suggest that these proteins modulate Fabry cerebral vasculopathy. 相似文献
127.
Regulation of voltage-gated sodium channels is crucial to firing patterns that constitute the output of medium spiny neurons (MSN), projecting neurons of the striatum. This modulation is thus critical for the final integration of information processed within the striatum. It has been shown that the adenylate cyclase pathway reduces sodium currents in MSN through channel phosphorylation by cAMP-dependent protein kinase. However, it is unknown whether a phospholipase C (PLC)-mediated signaling cascade could also modulate voltage-gated sodium channels within MSN. Using the whole-cell patch clamp technique, we investigated the effects of activation of two key components in PLC-mediated signaling cascades: protein kinase C (PKC) and inositol-1,4,5-triphosphate (IP(3)) receptors on voltage-dependent sodium current. Cellular dialysis with phorbol 12-myristate 13-acetate, an activator of PKC, significantly reduced peak sodium current amplitude, while adenophostin A, an activator of IP(3) receptors, significantly increased peak sodium current amplitude. This effect of adenophostin was abolished by calcium chelation or by FK506, an inhibitor of calcineurin. These results suggest an antagonistic role of PKC and IP(3) in the modulation of striatal voltage-gated sodium channels, peak current amplitude being decreased through phosphorylation by PKC and increased through dephosphorylation by calcineurin. 相似文献
128.
We used spontaneously active monolayer networks in vitro, cultured on thin film microelectrode arrays as experimental platforms for the determination of trimethyltin chloride (TMT) toxicity. Two different tissues of the mouse CNS (spinal cord and auditory cortex) exhibited characteristic and dose-dependent changes of their electrophysiological activity patterns after treatment with TMT, a standard neurotoxicant. Spinal cord networks began to respond to TMT at 1-2 microM and shut off activity at 4-7 microM. Auditory cortex cultures started to respond at 2-3 microM and shut off activity at 7-8 microM. Repeated applications of low doses of TMT always influenced the electrical activity in a reversible manner, with no overt cytotoxic effects. The inhibitory concentrations for a 50% reduction of activity (IC ) were 1.5+/-0.5 microM (spinal cord) and 4.3+/-0.9 microM (auditory cortex) indicating a relatively low interculture variability within one tissue type. The non-overlapping IC50 range for cortical and spinal cord cultures may suggest tissue specificity for network responses to TMT. Shut-off concentrations were found to be within a factor of two of the lethal concentrations reported for mice in vivo. Action potential amplitude and shape did not change even when complete cessation of activity was approached, suggesting that acute TMT applications did not affect neuronal metabolism that would lead to a lowering of membrane potentials. Our results suggest that spontaneously active monolayer networks in vitro are suitable for toxicological investigations since network activity can be influenced in a dose-dependent manner. These properties allow the development of neurotoxicity biosensors based on physiological responses of spontaneously active networks. 相似文献
129.
Luciano CA Russell JW Banerjee TK Quirk JM Scott LJ Dambrosia JM Barton NW Schiffmann R 《Muscle & nerve》2002,26(5):622-629
Fabry's disease is commonly associated with a painful, debilitating neuropathy. Characterization of the physiological abnormalities is an important step in evaluating response to specific therapies. Twenty-two patients with Fabry's disease, and with relatively preserved renal function, underwent conventional and near-nerve conduction studies, electromyography, sympathetic skin responses, and quantitative sensory testing (QST). Nerve conduction studies were mostly normal except for an increased frequency of median nerve entrapment at the wrist in 6 (27%) patients. Sympathetic skin responses were preserved in 19 of 20 (95%) of the patients. The QST showed increased or immeasurable cold and warm detection thresholds in patients, significantly different from controls (n = 28) in the hand (P < 0.001, P = 0.04, respectively) and foot (P < 0.001 for both). Cold thresholds were more often abnormal than were warm thresholds. Vibration thresholds were normal in the feet and, in some patients, elevated in the hand only, probably due to frequent median nerve entrapment at the wrist. Our findings suggest that the neuropathy of Fabry's disease is characterized by an increased prevalence of median nerve entrapment at the wrist and by thermal afferent fiber dysfunction in a length-dependent fashion, with greater impairment of cold than warm sensation. 相似文献
130.
Goker-Alpan O Schiffmann R Park JK Stubblefield BK Tayebi N Sidransky E 《The Journal of pediatrics》2003,143(2):273-276
Neuronopathic Gaucher disease, classically divided into two types, can have a continuum of phenotypes, often defying categorization. Nine children had an intermediate phenotype characterized by a delayed age of onset but rapidly progressive neurological disease, including refractory seizures and oculomotor abnormalities. There was genotypic heterogeneity among these patients. 相似文献