Search results for "cortical"

Cancer cells can affect behaviour of neighbouring cells by transferring molecules through extracellular vesicles

2017

Most cells release into the extracellular space membrane-bound structures of different sizes, origin and composition, collectively called extracellular vesicles (EVs) [1]. Tumor cells are much more active than normal cells in producing EVs. Because of this property, they are able to transfer both nucleic acids and proteins to the surrounding normal cells, thus inducing in these latter at least some transformed behavior. We previously showed that EVs produced by G26/24 oligodendroglioma cells can horizontally transfer to their neighbours radioactive proteins [2]. In addition, EVs released by these cells contain pro-apoptotic proteins, such as TRAIL and Fas-Ligand, able to induce apoptosis in…

Orally administered indicaxanthin is able to modulate human motor cortical excitability and plasticity

Opuntia Ficus Indica contains Indicaxanthin (IX), an antinflammatory and antioxidant betalaine pigment. This phytochemical is also able to cross the blood brain barrier (BBB) in rats and modulate neuronal activity. Considering these evidence, we aimed at investigating if orally administered IX could affect human brain tissue. 8 healthy and right-handed male subjects were recruited (20-45 years) with no history or clinical signs of neurological diseases, brain trauma or use of drugs acting on neuronal process, as assessed by a clinical neurologist. Non invasive Brain Stimulation and Neuromodulation (NIBS and NIN) instructions were applied in basal condition (T0) and 2 hours after having assu…

Tinnitus: a vision for research

2009

Tinnitus is classically defined as the perception of sound that has no external source. It was assumed to be primarily a disorder of the ear and has been linked to mechanisms equivalent to phantom pain; a pain sensation located to a no longer existing part of the body. Phantom pain is closely correlated with a cortical plasticity and with a reorganization of the somatosensory cortex. The end result is an alteration of neuronal activity, leading to tinnitus. Over the past decade, however, research on brain mechanisms of tinnitus has progressed rapidly, and insights have emerged into the possible neurological origins of tinnitus without any auditory dysfunction. Identification of the neurosci…

A failure of high level verbal response selection in progressive dynamic aphasia.

2005

Different theoretical interpretations have been offered in order to account for a specific language impairment termed dynamic aphasia. We report a patient (CH) who presented with a dynamic aphasia in the context of nonfluent progressive aphasia. CH had the hallmark of reduced spontaneous speech in the context of preserved naming, reading, and single word repetition and comprehension. Articulatory and grammatical difficulties were also present. CH had a very severe verbal generation impairment despite being able to describe pictorial scenes and action sequences well. In the experimental investigations CH was severely impaired in word, phrase, and sentence generation tasks when many competing…

Permeability properties of a three-cell type in vitro model of blood-brain barrier.

2005

We previously found that RBE4.B brain capillary endothelial cells (BCECs) form a layer with blood‐brain barrier (BBB) properties if co‐cultured with neurons for at least one week. As astrocytes are known to modulate BBB functions, we further set a culture system that included RBE4.B BCECs, neurons and astrocytes. In order to test formation of BBB, we measured the amount of (3)H‐sucrose able to cross the BCEC layer in this three‐cell type model of BBB. Herein we report that both neurons and astrocytes induce a decrease in the permeability of the BCEC layer to sucrose. These effects are synergic as if BCECs are cultured with both neurons and astrocytes for 5 days, permeability to sucrose decr…

Architecture in cortical bone and ultrasound transmission velocity

1993

The square of ultrasound transmission velocity in a material is correlated to the modulus of elasticity, which is an indicator of its mechanical properties. This might make the measurement of ultrasound transmission velocity useful in the noninvasive diagnosis of bone diseases. Bone, however, is not an isotropic material but is architecturally structured. The aim of our study was to investigate and especially to quantify the influence of architecture in cortical bone on ultrasound transmission velocity. Twenty-two rectangular, flat specimens of cortical bone were prepared from diaphysis of fresh pig radius. Ultrasound transmission velocity was measured parallel and perpendicular to directio…

Role of extension and compression in the evolution of the eastem margin of Iberia: the ESCI- València Trough seismic profile

1994

Carlos.Santisteban@uv.es The ESCI-València Trough deep seismic reflection profile crosses the eastern margin of Iberia and can be divided into three regions according to crustal structure. From NW to SE they are: a) the Ebro Basin, whit a 33 km thick continental crust wich remained almost undeformed during the Cenozoic and is very reflective in its lower part; b) the Continental Margin, made up of the Catalan-Valencian Domain and the Balearic Promontory with a thin (12 to 30 km thick) continental crust wich was deformed during the Cenozoic, extensional structures predominating the first domain and contractional structures in the second; and c) the Algerian Basin, with a 9 km thick oceanic c…

Role of motor cortex during drop jump: motor cortical excitability assessed with TMS and H-reflex stimulation

2005

Altered processing of sensory stimuli in patients with migraine.

2014

Migraine is a cyclic disorder, in which functional and morphological brain changes fluctuate over time, culminating periodically in an attack. In the migrainous brain, temporal processing of external stimuli and sequential recruitment of neuronal networks are often dysfunctional. These changes reflect complex CNS dysfunction patterns. Assessment of multimodal evoked potentials and nociceptive reflex responses can reveal altered patterns of the brain's electrophysiological activity, thereby aiding our understanding of the pathophysiology of migraine. In this Review, we summarize the most important findings on temporal processing of evoked and reflex responses in migraine. Considering these d…

Neurons and ECM regulate occludin localization in brain endothelial cells

2000

We report that extracellular matrix and neurons modulate the expression of occludin, one of the main components of tight junctions, by rat brain endothelial cells (RBE4.B). Of the three extracellular matrix proteins which we tested (collagen I, collagen IV, and laminin), collagen IV stimulated at the best the expression of occludin mRNA. The corresponding protein, however, was not synthesized. Significant amounts of occludin accumulated only when RBE4.B cells were cultured on collagen IV-coated inserts, in the presence of cortical neurons, plated on laminin-coated companion wells. Finally, occludin segregated at the cell periphery, only when endothelial cells were co- cultured with neurons …