Search results for "Neurologic"
showing 10 items of 473 documents
Study on the transient characteristic in the human visual system using masking experiments
1979
In this paper the visual masking effect is interpreted on the basic of the transient characteristic in two dimensional neuronal networks. The study investigates the suitability of the effect for use as a measurement method. It is shown that the stimulus distribution in space can be scanned at different points in time and that various dynamic characteristic values of the system can be measured.
Model predictions of the ionic mechanisms underlying the beating and bursting pacemaker characteristics of molluscan neurons
1976
The general properties of the excitable membrane on molluscan pacemaker neurons can be described on the basis of a fair amount of experimental evidence available in the literature. The neuronal membrane exhibits under voltage clamp an initial inward current carried by both Na+ and Ca2+ ions, the time- and voltage-dependent characteristics of which are similar to that of other excitable structures. The conductance mechanism for the two ion species and the transport kinetics appear to be closely similar. The time course and amplitude of the delayed outward current carried by K+ ions shows a marked dependence on the membrane potential. Characteristic for the molluscan neurons is the existence …
Analysis of a spatial orientation memory in Drosophila.
2008
Flexible goal-driven orientation requires that the position of a target be stored, especially in case the target moves out of sight. The capability to retain, recall and integrate such positional information into guiding behaviour has been summarized under the term spatial working memory. This kind of memory contains specific details of the presence that are not necessarily part of a long-term memory. Neurophysiological studies in primates indicate that sustained activity of neurons encodes the sensory information even though the object is no longer present. Furthermore they suggest that dopamine transmits the respective input to the prefrontal cortex, and simultaneous suppression by GABA s…
Neuronal network characteristics in the cat superior colliculus
1977
The system theoretical description of the superficial layers of neurons in the cat's superior colliculus is based on homogeneous linear space-time filters. The most important neurophysiological findings on the superior colliculus are simulated on the digital computer by generating suitable coupling functions and matching the space and time parameters. It is shown that the neurophysiological measurements can be interpreted by varying a few system parameters. The curves of velocity dependent responses, direction specificity and the effects of the colliculus specific surround are examined in particular. Computer simulation shows that such a surround can evaluate small moving stimuli differentl…
Parameters analysis of FitzHugh-Nagumo model for a reliable simulation
2014
International audience; Derived from the pioneer ionic Hodgkin-Huxley model and due to its simplicity and richness from a point view of nonlinear dynamics, the FitzHugh-Nagumo model has been one of the most successful neuron / cardiac cell model. It exists many variations of the original FHN model. Though these FHN type models help to enrich the dynamics of the FHN model. The parameters used in these models are often in biased conditions. The related results would be questionable. So, in this study, the aim is to find the parameter thresholds for one of the commonly used FHN model in order to pride a better simulation environment. The results showed at first that inappropriate time step and…
Imūnsupresīvās terapijas radītās neiroloģiskās blaknes pacientiem pēc nieru transplantācijas
2017
Mērķis: Neiroloģiskas blaknes dažādām imūnsupresīvām zālem nav daudz pētītas un iespējamo blakņu incidences un smaguma atšķirību identifikācia var palīdzēt optimizēt terapiju, lai palīdzētu uzlabot pacientu dzīves kvalitāti pēc transplatācijas. Šī pētījuma mērķis ir salīdzināt incidenci un smagumu neiroloģiskām blaknēm pacientiem, kuri saņem dažāda veida imūnsupresīvu terapiju pēc nieres pārstādīšanas un izvērtēt blakņu incidenci starp sieviešu un vīriešu dzimumiem. Metodes: Pētījums tika viekts Rīgas Paula Stradiņa Klīniskajā Universitātes Slimnīcā ambulatorajā nieru transplantāciju nodaļā. Pētījuma populācija sastāvēja no pacientiem, kuri vismaz sešus mēnešus pēc nieru transplantācijas sa…
Neuropathic pain. Redefinition and a grading system for clinical and research purposes.
2008
Pain usually results from activation of nociceptive afferents by actually or potentially tissue-damaging stimuli. Pain may also arise by activity generated within the nervous system without adequate stimulation of its peripheral sensory endings. For this type of pain, the International Association for the Study of Pain introduced the term neuropathic pain, defined as "pain initiated or caused by a primary lesion or dysfunction in the nervous system." While this definition has been useful in distinguishing some characteristics of neuropathic and nociceptive types of pain, it lacks defined boundaries. Since the sensitivity of the nociceptive system is modulated by its adequate activation (e.g…
Efectos agudos de una sesión de entrenamiento vibratorio sobre la espasticidad en personas con Esclerosis Múltiple: resultados preliminares.
2020
La esclerosis múltiple (EM) es una enfermedad neurológica progresiva, que conduce a un declive de la función física, siendo la espasticidad uno de los síntomas más recurrentes en esta población. En los últimos años, el entrenamiento vibratorio de cuerpo completo (WBVT) ha mostrado beneficios en la capacidad funcional, la función neuromuscular o la calidad de vida en personas con EM. Sin embargo, los efectos agudos de una sesión de WBVT sobre variables como la espasticidad son todavía desconocidos. Por ello, los objetivos principales de este estudio fueron analizar los efectos agudos del WBVT sobre la espasticidad de la rodilla, así como conocer las diferencias en esta variable entre la pier…
Care management in a French cohort with Down syndrome from the AnDDI-Rares/CNSA study.
2021
Down syndrome (DS) is a genetic neurodevelopmental disorder. In individuals with DS, a multidisciplinary approach to care is required to prevent multiple medical complications. The aim of this study was to describe the rehabilitation, medical care, and educational and social support provided to school-aged French DS patients with varying neuropsychological profiles. A mixed study was conducted. Quantitative data were obtained from a French multicentre study that included patients aged 4-20 years with diverse genetic syndromes. Qualitative data were collected by semi-structured face-to-face interviews and focus groups. Ninety-five DS subjects with a mean age of 10.9 years were included. Sixt…
The Utility of BDNF Detection in Assessing Severity of Huntington's Disease.
2021
Brain-derived neurotrophic factor (BDNF) is involved in the survival and maturation of neurons, and also promotes and controls neurogenesis. Its levels are lowered in many neurodegenerative diseases, including Huntington’s disease (HD). Clinical pictures of HD can be very diverse, which makes it difficult to assess its severity