Synapsins are synaptic-vesicle-associated phosphoproteins implicated in the regulation of neurotransmitter release and excitability of neuronal networks. Mutation of synapsin genes in mouse and human causes epilepsy. To understand the role of the highly conserved synapsin domain E in the dynamics of release from mammalian inhibitory neurons, we generated mice that selectively overexpress the most conserved part of this domain in cerebellar Purkinje cells.
View Article and Find Full Text PDFDynamic modulation of the actin cytoskeleton is critical for synaptic plasticity, abnormalities of which are thought to contribute to mental illness and addiction. Here we report that mice lacking Eps8, a regulator of actin dynamics, are resistant to some acute intoxicating effects of ethanol and show increased ethanol consumption. In the brain, the N-methyl-D-aspartate (NMDA) receptor is a major target of ethanol.
View Article and Find Full Text PDFTo evaluate the role of pulmonary surfactant in the prevention of lung injury caused by mechanical ventilation (MV) at low end-expiratory volumes, lung mechanics and morphometry were assessed in three groups of eight normal, open-chest rabbits ventilated for 3-4 h at zero end-expiratory pressure (ZEEP) with physiological tidal volumes (Vt = 10 ml/kg). One group was left untreated (group A); the other two received surfactant intratracheally (group B) or aerosolized dioctylsodiumsulfosuccinate (group C) before MV on ZEEP. Relative to initial MV on positive end-expiratory pressure (PEEP; 2.
View Article and Find Full Text PDFQuality of life (QoL) assessment in children with coagulation disorders is a relatively unstudied area. While hemophilia-specific questionnaires (such as Haemo-QoL) are available, no instrument for children with idiopathic thrombocytopenic purpura (ITP) has been validated yet. A disease-specific questionnaire for children with ITP was therefore developed (ITP-QoL) in three phases: (a) a preparatory phase; (b) a developmental phase; (c) a pilot testing phase.
View Article and Find Full Text PDFgamma-Aminobutyric acid (GABA)(B) receptors are known to enhance activation of Kir3 channels generating G-protein-dependent inward rectifier K(+)-currents (GIRK). In some neurons, GABA(B) receptors either cause a tonic GIRK activation or generate a late K(+)-dependent inhibitory postsynaptic current component. However, other neurons express Kir2 channels, which generate a constitutive inward rectifier K(+)-current (CIRK) without requiring G-protein activation.
View Article and Find Full Text PDFAlthough Golgi cells (GoCs), the main type of inhibitory interneuron in the cerebellar granular layer (GL), are thought to play a central role in cerebellar network function, their excitable properties have remained unexplored. GoCs fire rhythmically in vivo and in slices, but it was unclear whether this activity originated from pacemaker ionic mechanisms. We explored this issue in acute cerebellar slices from 3-week-old rats by combining loose cell-attached (LCA) and whole-cell (WC) recordings.
View Article and Find Full Text PDFCerebellar neurones show complex and differentiated mechanisms of action potential generation that have been proposed to depend on peculiar properties of their voltage-dependent Na+ currents. In this study we analysed voltage-dependent Na(+) currents of rat cerebellar granule cells (GCs) by performing whole-cell, patch-clamp experiments in acute rat cerebellar slices. A transient Na+ current (I(NaT)) was always present and had the properties of a typical fast-activating/inactivating Na+ current.
View Article and Find Full Text PDFPsychotherapy (Chic)
October 2012
The Culturally Competent Relaxation Intervention (CCRI) was developed and assessed with 25 Latino adults. In contrast to traditional psychotherapeutic and relaxation interventions, which are highly influenced by individualistic/idiocentric (the tendency to define oneself in isolation from others) assumptions, the CCRI was designed according to an allocentric self-orientation (the tendency to define oneself in relationship with others), which is prevalent among Latinos. This pilot study found preliminary evidence suggesting that participants who were more allocentric had higher levels of treatment adherence and, contrary to what was expected, idiocentric levels were not inversely related with treatment adherence.
View Article and Find Full Text PDFLymphedema represents one of the major problem of morbidity in breast cancer therapy. Approximately 15-30% of patients show more or less severe lymphedema of the arm, following cancer therapy. Main pathogenetic mechanisms, risk factors, main grading criteria and scales as LENT-SOMA, CTCv2, CTCAE v3 are presented.
View Article and Find Full Text PDFLong-term potentiation (LTP) is a synaptic change supposed to provide the cellular basis for learning and memory in brain neuronal circuits. Although specific LTP expression mechanisms could be critical to determine the dynamics of repetitive neurotransmission, this important issue remained largely unexplored. In this paper, we have performed whole cell patch-clamp recordings of mossy fiber-granule cell LTP in acute rat cerebellar slices and studied its computational implications with a mathematical model.
View Article and Find Full Text PDFFlooded soils with rooted aquatic macrophytes have adjacent aerobic and anaerobic zones at the soil-water interface and rhizosphere where many common soil constituents undergo sequential oxidation and reduction reactions. To investigate whether pentachlorophenol (PCP) mineralization would also be enhanced under these conditions, a laboratory study was conducted to determine the conversion of [14C]PCP to 14CO2, 14CH4 and [14C]humic substances in soil microcosms with established aerobic-anaerobic zones at the soil-water interface and rice (Oryza sativa) rhizosphere. Contrary to what was expected, PCP was least rapidly degraded in rhizosphere-soil microcosms that contained the most extensive amounts of aerobic-anaerobic interfaces (63% PCP loss in 82 d) and was most rapidly degraded in soil microcosms that lacked redox interfaces in the soil profile (94% PCP loss in 82 d).
View Article and Find Full Text PDFThe mf-GrC relay provides the case of a synapse at which elementary neurotransmission mechanisms are particularly well understood allowing a precise investigation of synaptic plasticity. An interesting consequence is that a presynaptic mechanism of LTP could be precisely documented on the basis of quantal analysis. By being presynaptically expressed, LTP becomes instrumental to regulation of short-term synaptic dynamics thereby controlling time-dependent transformations of the incoming mossy fiber input.
View Article and Find Full Text PDFAm J Respir Crit Care Med
September 2005
Rationale: Anesthesia-induced uncoupling of upper airway dilating and inspiratory pump muscles activation may cause inspiratory flow limitation, thereby mimicking obstructive sleep apnea/hypopnea.
Objectives: Determine whether inspiratory flow limitation occurs in spontaneously breathing anesthetized rabbits and whether this can be reversed by direct hypoglossal nerve stimulation and by the application of continuous positive airway pressure.
Methods: Ten New Zealand White rabbits were anesthetized, instrumented, and studied supine while breathing spontaneously at ambient pressure or during the application of positive or negative airway pressure.
Bioresour Technol
March 2006
Alum is used to reduce environmental pollutants in poultry production. Alum decreases NH3 volatilization and increases total N and NH4+-N compared to untreated poultry manure. Nitrification in poultry wastes could therefore be stimulated due to higher NH4+ concentrations or could be inhibited because the soil environment is acidified.
View Article and Find Full Text PDFVariations in intracellular calcium concentration ([Ca2+]i) provide a critical signal for synaptic plasticity. In accordance with Hebb's postulate (Hebb, 1949), an increase in postsynaptic [Ca2+]i can induce bidirectional changes in synaptic strength depending on activation of specific biochemical pathways (Bienenstock et al., 1982; Lisman, 1989; Stanton and Sejnowski, 1989).
View Article and Find Full Text PDFLung mechanics, exhaled NO (NOe), and TNF-alpha in serum and bronchoalveolar lavage fluid were assessed in eight closed and eight open chest, normal anesthetized rabbits undergoing prolonged (3-4 h) mechanical ventilation (MV) at low volume with physiological tidal volumes (10 ml/kg). Relative to initial MV on positive end-expiratory pressure (PEEP), MV at low volume increased lung quasi-static elastance (+267 and +281%), airway (+471 and +382%) and viscolelastic resistance (+480 and +294%), and decreased NOe (-42 and -25%) in closed and open chest rabbits, respectively. After restoration of PEEP, viscoelastic resistance returned to control, whereas airway resistance remained elevated (+120 and +31%) and NOe low (-25 and -20%) in both groups of rabbits.
View Article and Find Full Text PDFCalcium binding proteins, such as calretinin, are abundantly expressed in distinctive patterns in the central nervous system but their physiological function remains poorly understood. Calretinin is expressed in cerebellar granule cells which provide the major excitatory input to Purkinje cells through parallel fibers. Calretinin deficient mice exhibit dramatic alterations in motor coordination and in Purkinje cell firing recorded in vivo through unknown mechanisms.
View Article and Find Full Text PDFIn the last decade, the physiology of cerebellar neurons and synapses has been extended to a considerable extent. We have found that the mossy fiber-granule cell relay can generate a complex form of long-term potentiation (mf-GrC LTP) following high-frequency mf discharge. Induction.
View Article and Find Full Text PDFThe frictional behaviour of rabbit's visceral pleura sliding against parietal pleura was assessed in vitro while oscillating at physiological velocities and amplitudes under physiological normal forces. For sliding velocities up to 3 cm s(-1) and normal compressive loads up to 12 cm H2O, the average value of the coefficient of kinetic friction (mu) was constant at 0.019 +/- 0.
View Article and Find Full Text PDFDeferiprone (DFO) at the standard daily dose of 75 mg/kg was given to 13 transfusion-dependent patients with thalassemia in whom conventional desferrioxamine (DFX) therapy had proven ineffective and caused adverse side effects. In six patients, serum ferritin and alanine aminotransferase levels decreased significantly and urinary iron excretion increased. In seven patients in whom DFO administration alone was ineffectual, DFX was added at a daily dose of 40 to 50 mg/kg given subcutaneously for 7 to 10 days following transfusion.
View Article and Find Full Text PDFBackground: and objective: Patients with COPD exhibit increased inspiratory work and dyspnea due to dynamic hyperinflation caused by expiratory flow limitation. Helium-oxygen mixtures (ie, heliox) have been used in treating these patients on the assumption that, by lowering airway resistance, they might be beneficial.
Methods: In 22 patients with COPD, the presence of expiratory flow limitation was assessed with patients in the sitting and supine positions using the negative expiratory pressure technique, and the effects of heliox (80% He, 20% O2) on breathing pattern, expiratory flow limitation, and dynamic hyperinflation, evaluated from the change in inspiratory capacity (IC), were measured at rest and were compared with those due to inhaled salbutamol.
During long-term potentiation (LTP) at mossy fibre-granule cell synapses in rat cerebellum synaptic transmission and granule cell intrinsic excitability are enhanced. Although it is clear that changes in granule cell excitability are mediated postsynaptically, there is as yet no direct evidence for the site and mechanism of changes in transmission. To approach this problem, evoked postsynaptic currents (EPSCs) and miniature synaptic currents (mEPSCs) were recorded by patch-clamp in cerebellar slices obtained from P17-P23 rats.
View Article and Find Full Text PDFLung mechanics and morphometry were assessed in two groups of nine normal open-chest rabbits mechanically ventilated (MV) for 3-4 h at zero end-expiratory pressure (ZEEP) with physiological tidal volumes (Vt; 11 ml/kg) and high (group A) or low (group B) inflation flow (44 and 6.1 ml x kg(-1) x s(-1), respectively). Relative to initial MV on positive end-expiratory pressure (PEEP; 2.
View Article and Find Full Text PDFCalcium-binding proteins such as calretinin are abundantly expressed in distinctive patterns in the CNS, but their physiological function remains poorly understood. Calretinin is expressed in cerebellar granule cells, which provide the major excitatory input to Purkinje cells through parallel fibers. Calretinin-deficient mice exhibit dramatic alterations in motor coordination and Purkinje cell firing recorded in vivo through unknown mechanisms.
View Article and Find Full Text PDFNitric oxide (NO) is a candidate retrograde messenger in long-term potentiation (LTP). The NO metabolic pathway is expressed in the cerebellar granule cell layer but its physiological role remained unknown. In this paper we have investigated the role of NO in cerebellar mossy fiber-granule cell LTP, which has postsynaptic N-methyl-d-aspartate (NMDA) receptor-dependent induction.
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