1,721,106 research outputs found

    Canti popolari Monferrini, raccolti ed annotati del Dr Giuseppe Ferraro, 1870

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    P. G. Canti popolari Monferrini, raccolti ed annotati del Dr Giuseppe Ferraro, 1870. In: Romania, tome 1 n°2, 1872. pp. 255-257

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Microtubule Dynamics and Neuronal Excitability: Advances on Cytoskeletal Components Implicated in Epileptic Phenomena

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    Extensive researches have deepened knowledge on the role of synaptic components in epileptogenesis, but limited attention has been devoted to the potential implication of the cytoskeleton. The study of the development of epilepsy and hyperexcitability states involves molecular, synaptic, and structural alterations of neuronal bioelectric activity. In this paper we aim to explore the neurobiological targets involved in microtubule functioning and cytoskeletal transport, i.e. how dynamic scaffolding of microtubules can influence neuronal morphology and excitability, in order to suggest a potential role for microtubule dynamics in the processes turning a normal neuronal network in a hyperexcited one. Pathophysiological alterations of microtubule dynamics inducing neurodegeneration, network remodeling and relative impairment on synaptic transmission were overviewed. Recent researches were reported on the phosphorylation state of microtubule-associated proteins such as tau in neurodegenerative diseases and epileptic states, but also on the effect of microtubule-active agents influencing cytoskeleton destabilization in epilepsy models. The manipulation of microtubule polymerization was found effective in the modulation of hyperexcitability. In addition, it was considered the importance of microtubules and related neurotrophic factors during neural development since they are essential for the formation of a properly functional neuronal network. Otherwise, this can lead to cognitive deficits, hyperexcitability phenomena and neurodevelopmental disorders. Lastly, we evaluated the role of microtubule dynamics on neuronal efficiency considering their importance in the transport of mitochondria, cellular elements fulfilling energy requirements for neuronal activity, and a putative influence on cannabinoid-mediated neuroprotection. This review provides novel perspectives for the implication of microtubule dynamics in the development of epileptic phenomena

    3D Printing Neuron Equivalent Circuits: An Undergraduate Laboratory Exercise

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    The electrical equivalent circuit for a neuron is composed of common electrical components in a configuration that replicates the passive electrical properties and behaviors of the neural membrane. It is a powerful tool used to derive such fundamental neurophysiological equations as the Hodgkin-Huxley equations, and it is also the basis for well-known exercises that help students to model the passive (Ohmic) properties of the neuronal membrane. Unfortunately, as these exercises require basic knowledge of electronics, they are generally not physically conducted in biomedical courses, but remain merely conceptual exercises in a book or simulations on a computer. In such manifestations, they lack the “hands-on” appeal for students and teachers afforded by laboratory experimentations. Here, we propose a new approach to these experiments in which a desktop 3D printer and conductive paint are used to build the circuit and the popular programmable microcontroller the Arduino UNO is used as a graphical oscilloscope when connected to a standard computer. This set-up has the advantage to be very easy to build and less clumsy than a circuit in a prototyping board or connected with alligator clips, with the added benefit of being conveniently portable for classroom demonstrations. Most importantly, this method allows the monitoring of real-time changes in the current flowing through the circuit by means of a graphical display (by way of the Arduino) at a fraction of the cost of commercially available oscilloscopes

    Cannabinoids, TRPV and nitric oxide: the three ring circus of neuronal excitability

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    Endocannabinoid system is considered a relevant player in the regulation of neuronal excitability, since it contributes to maintaining the balance of the synaptic ionic milieu. Perturbations to bioelectric conductances have been implicated in the pathophysiological processes leading to hyperexcitability and epileptic seizures. Cannabinoid influence on neurosignalling is exerted on classic receptor-mediated mechanisms or on further molecular targets. Among these, transient receptor potential vanilloid (TRPV) are ionic channels modulated by cannabinoids that are involved in the transduction of a plethora of stimuli and trigger fundamental downstream pathways in the post-synaptic site. In this review, we aim at providing a brief summary of the most recent data about the cross-talk between cannabinoid system and TRPV channels, drawing attention on their role on neuronal hyperexcitability. Then, we aim to unveil a plausible point of interaction between these neural signalling systems taking into consideration nitric oxide, a gaseous molecule inducing profound modifications to neural performances. From this novel perspective, we struggle to propose innovative cellular mechanisms in the regulation of hyperexcitability phenomena, with the goal of exploring plausible CB-related mechanisms underpinning epileptic seizures
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