Search results for "Cerebellum"

Effects of γ-Butyrobetaine and Mildronate on Nitric Oxide Production in Lipopolysaccharide-Treated Rats

2008

Production of nitric oxide was measured in lipopolysaccharide-treated rats (10 mg/kg, 4 hr) using the electron paramagnetic resonance method. As compared to the control animals, the nitric oxide level in liver of lipopolysaccharide-treated rats increased from 27.6+/-4.7 to 1485+/-129 ng/g tissue, in heart from 4.8+/-0.7 to 271+/-26 ng/g tissue, in blood from 33.6+/-12.4 to 638+/-136 ng/g tissue, in kidney from 3.3+/-0.5 to 356+/-31 ng/g tissue, in brain cortex from 46.0+/-3.4 to 227+/-27 ng/g tissue, in cerebellum from 27.7+/-2.6 to 218+/-30 ng/g tissue, and in testes from 13.8+/-1.1 to 86+/-8 ng/g tissue. Administration of the antiischaemic drug, mildronate (120 mg/kg) caused a significant…

Left but not right temporal involvement in opaque idiom comprehension: a repetitive transcranial magnetic stimulation study

2004

Abstract It has been suggested that figurative language, which includes idioms, is controlled by the right hemisphere. We tested the right hemisphere hypothesis by using repetitive transcranial magnetic stimulation (rTMS) to transiently disrupt the function of the frontal and temporal areas of the right versus left hemisphere in a group of normal participants involved in a task of opaque idiom versus literal sentence comprehension. Forty opaque, nonambiguous idioms were selected. Fifteen young healthy participants underwent rTMS in two sessions. The experiment was run in five blocks, corresponding to the four stimulated scalp positions (left frontal and temporal and right frontal and tempor…

Presynaptic CB1 Receptors Regulate Synaptic Plasticity at Cerebellar Parallel Fiber Synapses

2011

Endocannabinoids are potent regulators of synaptic strength. They are generally thought to modify neurotransmitter release through retrograde activation of presynaptic type 1 cannabinoid receptors (CB1Rs). In the cerebellar cortex, CB1Rs regulate several forms of synaptic plasticity at synapses onto Purkinje cells, including presynaptically expressed short-term plasticity and, somewhat paradoxically, a postsynaptic form of long-term depression (LTD). Here we have generated mice in which CB1Rs were selectively eliminated from cerebellar granule cells, whose axons form parallel fibers. We find that in these mice, endocannabinoid-dependent short-term plasticity is eliminated at parallel fiber…

Differentiation-regulated loss of the polysialylated embryonic form and expression of the different polypeptides of the neural cell adhesion molecule…

1989

The expression of the neural cell adhesion molecule (N-CAM) on cultured murine oligodendrocytes, their precursors, and myelin was examined by indirect immunofluorescence, biosynthetic radiolabeling followed by immunoprecipitation and Western blot analysis, using antibodies specific for various forms of the molecule. In all culture systems studied, whether the oligodendrocytes were cultured as an enriched fraction containing precursor cells or in the presence of astrocytes and neurons, a similar differentiation-stage-related expression of N-CAM was seen. At early developmental stages many tetanus toxin receptor- and A2B5 antigen-positive putative oligodendrocyte precursors with bipolar morph…

Excitotoxin-induced changes in transglutaminase during differentiation of cerebellar granule cells

2002

Excitotoxicity induced by NMDA receptor stimulation is able to increase the activity of many enzymes involved in neuronal cell death. Primary cultures of rat cerebellar granule cells were used to elucidate the role of transglutaminase reaction in the excitotoxic cell response, and to evaluate the role of glutamate receptors in cell survival and degeneration. Granule neurons, maintained in vitro for two weeks, were exposed to NMDA at different stages of differentiation. Following NMDA receptor activation, increases in transglutaminase activity were observed in cell cultures. The levels of enzyme activity were higher in cells at 5 days in vitro than in those at 8-9 or 13-14 days in vitro. Mor…

NEUROPHYSIOLOGICAL AND NEUROCHEMICAL STUDIES WITH THE ISONICOTINOYLHYDRAZONE OF PYRIDOXAL 5-PHOSPHATE.

1964

TALPID3 controls centrosome and cell polarity and the human ortholog KIAA0586 is mutated in Joubert syndrome (JBTS23)

2015

Joubert syndrome (JBTS) is a severe recessive neurodevelopmental ciliopathy which can affect several organ systems. Mutations in known JBTS genes account for approximately half of the cases. By homozygosity mapping and whole-exome sequencing, we identified a novel locus, JBTS23, with a homozygous splice site mutation in KIAA0586 (alias TALPID3), a known lethal ciliopathy locus in model organisms. Truncating KIAA0586 mutations were identified in two additional patients with JBTS. One mutation, c.428delG (p.Arg143Lysfs*4), is unexpectedly common in the general population and may be a major contributor to JBTS. We demonstrate KIAA0586 protein localization at the basal body in human and mouse p…

Integration of Gravitational Torques in Cerebellar Pathways Allows for the Dynamic Inverse Computation of Vertical Pointing Movements of a Robot Arm

2008

BackgroundSeveral authors suggested that gravitational forces are centrally represented in the brain for planning, control and sensorimotor predictions of movements. Furthermore, some studies proposed that the cerebellum computes the inverse dynamics (internal inverse model) whereas others suggested that it computes sensorimotor predictions (internal forward model).Methodology/principal findingsThis study proposes a model of cerebellar pathways deduced from both biological and physical constraints. The model learns the dynamic inverse computation of the effect of gravitational torques from its sensorimotor predictions without calculating an explicit inverse computation. By using supervised …

When the brain goes diving: glial oxidative metabolism may confer hypoxia tolerance to the seal brain.

2009

Deep diving mammals have developed strategies to cope with limited oxygen availability when submerged. These adaptations are associated with an increased neuronal hypoxia tolerance. Brain neurons of the hooded seal Cysto- phora cristata remain much longer active in hypoxic condi- tions than those of mice. To understand the cellular basis of neuronal hypoxia tolerance, we studied neuroglobin and cy- tochrome c in C. cristata brain. Neuroglobin, a respiratory protein typically found in vertebrate neurons, displays three unique amino acid substitutions in hooded seal. However, these substitutions unlikely contribute to a modulation of O2 affinity. Moreover, there is no significant difference i…

Age-related changes in the regulation of transcription factor NF-kappa B in rat brain.

1997

Aging process involves an increase in stress at cellular level. We studied whether aging affects the regulation of stress responsive transcription factor NF-kappa B in brain samples of Wistar rats. Hippocampus, cerebellum, and temporal and frontal lobes of cortex were studied. We observed a significant up-regulation in the constitutive, nucleus-located NF-kappa B binding activity in 30-month-old Wistar rats compared to young and 18-month-old rats. The increase was most prominent in cerebellum and in frontal cortex, but age-related changes did not occur in hippocampus. Inducible, cytoplasmic NF-kappa B binding activity was not affected by aging in any of the samples studied. Western blot ass…