Search results for "Neurosciences. Biological psychiatry. Neuropsychiatry"
showing 10 items of 652 documents
Spontaneous spinal discitis and spondylodiscitis: Clinicotherapeutic remarks
2017
Spinal infections are rare (their incidence is estimated in about the 5% of all osteomyelitis) and severe pathologies. They are usually identified with different names, as disk space infection, spondylodiscitis, and vertebral osteomyelitis. Spondylodiscitis is the most frequent among spinal infections. The etiology might be due to bacteria, fungi, and parasites and might affect many anatomical structures. The reported incidence is increased in the last years.[1,2] The disease can be classified according to the involved anatomical structure: Vertebral osteomyelitis Discitis and spondylodiscitis Spinal canal infections Adjacent soft tissue infections. In adult patients, the terms osteomyeliti…
An investigation of the neural circuits underlying reaching and reach-to-grasp movements: from planning to execution
2014
Experimental evidence suggests the existence of a sophisticated brain circuit specifically dedicated to reach-to-grasp planning and execution, both in human and non-human primates (Castiello, 2005). Studies accomplished by means of neuroimaging techniques suggest the hypothesis of a dichotomy between a "reach-to-grasp" circuit, involving the anterior intraparietal area, the dorsal and ventral premotor cortices (PMd and PMv - Castiello and Begliomini, 2008; Filimon, 2010) and a "reaching" circuit involving the medial intraparietal area and the superior parieto-occipital cortex (Culham et al., 2006). However, the time course characterizing the involvement of these regions during the planning …
In praise of artifice reloaded: Caution with natural image databases in modeling vision
2019
Subjective image quality databases are a major source of raw data on how the visual system works in naturalistic environments. These databases describe the sensitivity of many observers to a wide range of distortions of different nature and intensity seen on top of a variety of natural images. Data of this kind seems to open a number of possibilities for the vision scientist to check the models in realistic scenarios. However, while these natural databases are great benchmarks for models developed in some other way (e.g., by using the well-controlled artificial stimuli of traditional psychophysics), they should be carefully used when trying to fit vision models. Given the high dimensionalit…
Boosting working memory with accelerated clocks
2021
Our perception of time varies with the degree of cognitive engagement in tasks. The perceived passage of time accelerates while working on demanding tasks, whereas time appears to drag during boring situations. Our experiment aimed at investigating whether this relationship is mutual: Can manipulated announcements of elapsed time systematically affect the attentional resources applied to a cognitive task? We measured behavioral performance and the EEG in a whole report working memory paradigm with six items of different colors that each had to be reported after a short delay period. The 32 participants were informed about the current time after each 20 trials, while the clock was running at…
Near- and Far-Surround Suppression in Human Motion Discrimination.
2018
The spatial context has strong effects on visual processing. Psychophysics and modeling studies have provided evidence that the surround context can systematically modulate the perception of center stimuli. For motion direction, these center-surround interactions are considered to come from spatio-directional interactions between direction of motion tuned neurons, which are attributed to the middle temporal (MT) area. Here, we investigated through psychophysics experiments on human subjects changes with spatial separation in center-surround inhibition and motion direction interactions. Center-surround motion repulsion effects were measured under near-and far-surround conditions. Using a sim…
Vulnerability of peripheral catecholaminergic neurons to MPTP is not regulated by alpha-synuclein.
2010
Although generally considered a prototypical movement disorder, Parkinson's disease is commonly associated with a broad-spectrum of non-motor symptoms, including autonomic dysfunctions caused by significant alterations in catecholaminergic neurons of the peripheral sympathetic nervous system. Here we present evidence that alpha-synuclein is highly expressed by sympathetic ganglion neurons throughout embryonic and postnatal life and that it is found in tyrosine hydroxylase-positive sympathetic fibers innervating the heart of adult mice. However, mice deficient in alpha-synuclein do not exhibit any apparent alterations in sympathetic development. Sympathetic neurons isolated from mouse embryo…
WNK3 Maintains the GABAergic Inhibitory Tone, Synaptic Excitation and Neuronal Excitability via Regulation of KCC2 Cotransporter in Mature Neurons
2021
The activation of chloride (Cl-)permeable gamma (γ)-aminobutyric acid type A(GABAA) receptors induces synaptic inhibition in mature and excitation in immature neurons. This developmental "switch" in GABA function controlled by its polarity depends on the postnatal decrease in intraneuronal Cl- concentration mediated by KCC2, a member of cation-chloride cotransporters (CCCs). The serine-threonine kinase WNK3 (With No Lysine [K]), is a potent regulator of all CCCs and is expressed in neurons. Here, we characterized the functions of WNK3 and its role in GABAergic signaling in cultured embryonic day 18 (E18) hippocampal neurons. We observed a decrease in WNK3 expression as neurons mature. Knock…
Motor imagery
2015
International audience; Before participating in a space mission, astronauts undergo parabolic-flight and underwater training to facilitate their subsequent adaptation to weightlessness. Unfortunately, similar training methods can't be used to prepare re adaptation to planetary gravity. Here, we propose a quick, simple and inexpensive approach that could be used to prepare astronauts both for the absence and for the renewed presence of gravity. This approach is based on motor imagery (MI), a process in which actions are produced in working memory without any overt output. Training protocols based on MI have repeatedly been shown to modify brain circuitry and to improve motor performance in h…
The Role of the Cerebellum in Social and Non-Social Action Sequences: A Preliminary LF-rTMS Study
2021
An increasing number of studies demonstrated the involvement of the cerebellum in (social) sequence processing. The current preliminary study is the first to investigate the causal involvement of the cerebellum in sequence generation, using low-frequency repetitive transcranial magnetic stimulation (LF-rTMS). By targeting the posterior cerebellum, we hypothesized that the induced neuro-excitability modulation would lead to altered performance on a Picture and Story sequencing task, which involve the generation of the correct chronological order of various social and non-social stories depicted in cartoons or sentences. Our results indicate that participants receiving LF-rTMS over the cerebe…
Improving neglect by TMS.
2006
Hemispatial neglect refers to the defective ability of patients to explore or act upon the side of space contralateral to the lesion and to attend to stimuli presented in that portion of space. Evidence from animal models suggests that many of the behavioural sequelae associated with visual neglect may result not solely from the size of the lesion, but also from a pathological state of increased inhibition exerted on the damaged hemisphere by the contralesional hemisphere. On the basis of these potential mechanisms underlying neglect, in this review we discuss therapeutic approaches, focusing particularly on recent research using transcranial magnetic stimulation (TMS). This technique, besi…