Search results for "neuron"
showing 10 items of 2611 documents
The role of synergies within generative models of action execution and recognition: A computational perspective. Comment on "Grasping synergies: A mo…
2015
Controlling the body – given its huge number of degrees of freedom – poses severe computational challenges. Mounting evidence suggests that the brain alleviates this problem by exploiting “synergies”, or patterns of muscle activities (and/or movement dynamics and kinematics) that can be combined to control action, rather than controlling individual muscles of joints [1–10]. D’Ausilio et al. [11] explain how this view of motor organization based on synergies can profoundly change the way we interpret studies of action recognition in humans and monkeys, and in particular the controversy on the “granularity” of the mirror neuron system (MNs): whether it encodes either (lower) kinematic aspects…
Uccidere spazi. Microanalisi della corrida
2013
Che senso ha fare corride oggi? Chi è lo spettatore della corrida nell’Europa contemporanea? Da almeno tre generazioni il Tardo Occidente aspetta una fine che non arriva e recupera spazi in disuso per allestire rifugi di fortuna. La corrida è una di queste camere ambigue, dove sistema e critica al sistema coabitano per necessità come il vecchio e la sua badante. Ma l’arena è anche una parentesi vuota: ogni epoca l’ha riempita di metafore che avevano senso in quel dato momento. Allora quali aporie, quali mancanze lo spettatore della corrida porta con sé oggi nel teatro della tauromachia? Che cosa accade nel corpo-mente di chi guarda uomini e tori che cercano di uccidersi a vicenda? Con quest…
An Original Convolution Model to analyze Graph Network Distribution Features
2022
Modern Graph Theory is a newly emerging field that involves all of those approaches that study graphs differently from Classic Graph Theory. The main difference between Classic and Modern Graph Theory regards the analysis and the use of graph's structures (micro/macro). The former aims to solve tasks hosted on graph nodes, most of the time with no insight into the global graph structure, the latter aims to analyze and discover the most salient features characterizing a whole network of each graph, like degree distributions, hubs, clustering coefficient and network motifs. The activities carried out during the PhD period concerned, after a careful preliminary study on the applications of the…
Rat CNS neurons are not yet programmed to shorten their chromatin repeat length at the end of fetal neurogenesis.
1986
Neurons from rat fetal cerebral hemispheres were grown in a synthetic medium (Maat medium), as previously described, for different periods of time. The repeat length of their chromatin was determined by micrococcal nuclease digestion and compared with that of neurons isolated from postnatal rat brain of corresponding ages. In contrast to the in vivo situation, we found that neurons, dissociated at the 16th gestational day and cultured in vitro, did not undergo the shortening of their chromatin repeat, thus indicating that, at the end of their mitotic cycles, they are not yet programmed to this event. © 1986.
Effects of low frequency electric fields on synaptic integration in hippocampal CA1 pyramidal neurons: implications for power line emissions
2014
The possible cognitive effects of low frequency external electric fields, such as those generated by power lines, are poorly understood. Their functional consequences for mechanisms at the single neuron level are very difficult to study and identify experimentally, especially in vivo. The major open problem is that experimental investigations on humans have given inconsistent or contradictory results, making it difficult to estimate the possible effects of external low frequency electric fields on cognitive functions. Here we investigate this issue with a realistic model of hippocampal CA1 pyramidal neurons. The model suggests how and why external electric fields, with environmentally obser…
Information – theoretic characterization of concurrent activity of neural spike trains
2021
The analysis of massively parallel spike train recordings facilitates investigation of communications and synchronization in neural networks. In this work we develop and evaluate a measure of concurrent neural activity, which is based on intrinsic firing properties of the recorded neural units. An overall single neuron activity is unfolded in time and decomposed into working and non-firing state, providing a coarse, binary representation of the neurons functional state. We propose a modified measure of mutual information to reflect the degree of simultaneous activation and concurrency in neural firing patterns. The measure is shown to be sensitive to both correlations and anti-correlations,…
Clinical manifestations of the anti-IgLON5 disease
2017
Objective:To report the presentation, main syndromes, human leukocyte antigen (HLA) association, and immunoglobulin G (IgG) subclass in the anti-IgLON5 disease: a disorder with parasomnias, sleep apnea, and IgLON5 antibodies.Methods:This was a retrospective clinical analysis of 22 patients. The IgG subclass was determined using reported techniques.Results:Patients' median age was 64 years (range 46–83). Symptoms that led to initial consultation included sleep problems (8 patients; 36%), gait abnormalities (8; 36%), bulbar dysfunction (3; 14%), chorea (2; 9%), and cognitive decline (1; 5%). By the time of diagnosis of the disorder, 4 syndromes were identified: (1) a sleep disorder with paras…
Human awareness and uses of odor cues in everyday life: Results from a questionnaire study in children
2008
The Children's Olfactory Behavior in Everyday Life questionnaire was developed to assess attention to, and uses of, odors in real-life situations, and to evaluate individual variations. The tool comprises 16 items prompting self-reports of active seeking, awareness and affective reactivity to odors of food, people and the environment. Children (102 girls, 113 boys) aged 6–10 years participated in the study. The results revealed that girls were significantly more olfaction-oriented than boys, especially towards the odors of people, self and the environment. An increasing ability of children to describe the odor facets of their perceptual world was found between 6 and 10 years, partly due to …
Reservoir computing model of prefrontal cortex creates novel combinations of previous navigation sequences from hippocampal place-cell replay with sp…
2019
As rats learn to search for multiple sources of food or water in a complex environment, they generate increasingly efficient trajectories between reward sites. Such spatial navigation capacity involves the replay of hippocampal place-cells during awake states, generating small sequences of spatially related place-cell activity that we call “snippets”. These snippets occur primarily during sharp-wave-ripples (SWRs). Here we focus on the role of such replay events, as the animal is learning a traveling salesperson task (TSP) across multiple trials. We hypothesize that snippet replay generates synthetic data that can substantially expand and restructure the experience available and make learni…
Kinetic Properties of Cl−Uptake Mediated by Na+-Dependent K+-2Cl−Cotransport in Immature Rat Neocortical Neurons
2007
GABA, the main inhibitory neurotransmitter in the adult nervous system, evokes depolarizing membrane responses in immature neurons, which are crucial for the generation of early network activity. Although it is well accepted that depolarizing GABA actions are caused by an elevated intracellular Cl−concentration ([Cl−]i), the mechanisms of Cl−accumulation in immature neurons are still a matter of debate. Using patch-clamp, microfluorimetric, immunohistochemical, and molecular biological approaches, we studied the mechanism of Cl−uptake in Cajal-Retzius (CR) cells of immature [postnatal day 0 (P0) to P3] rat neocortex. Gramicidin-perforated patch-clamp and 6-methoxy-N-ethylquinolinium-microfl…