1,721,139 research outputs found
Temporal Modulation of Spatial Borders in Rat Barrel Cortex
No full text Sheth, Bhavin R., Christopher I. Moore, and Mriganka Sur. Temporal modulation of spatial borders in rat barrel cortex. J. Neurophysiol. 79: 464–470, 1998. We examined the effects of varying vibrissa stimulation frequency on intrinsic signal and neuronal responses in rat barrel cortex. Optical imaging of intrinsic signals demonstrated that the region of cortex activated by deflection of a single vibrissa at 1 Hz is more diffuse and more widespread than the territory activated at 5 or 10 Hz. With the use of two different paradigms, constant time of stimulation and constant number of vibrissa deflections, we showed that the optically imaged spread of activity is more discrete at higher stimulation frequencies. We combined optical imaging with multiple electrode recording and confirmed that the neuronal response to individual vibrissa stimulation at the optically imaged center of activity is greater than the response away from the imaged center. Consistent with the imaging data, these recordings also showed no response to a second vibrissa deflection at 5 Hz at a peripheral recording site, though there was a significant response to a second vibrissa deflection at 1 Hz at the same peripheral site. These findings demonstrate that vibrissa stimulation at higher frequencies leads to more focused physiological responses in cortex. Thus the spread of activation in rat barrel cortex is modulated in a dynamic fashion by the frequency of vibrissa stimulation. </jats:p
The potential commercialization of neuronal replacement therapy using smart polymers
Get PDFThesis (S.M.M.O.T.)--Massachusetts Institute of Technology, Sloan School of Management, Management of Technology Program, 2005.Includes bibliographical references (leaves 108-122).NeuroBioChip Device is a programmable, biocompatible, biodegradable, polymer matrix which allows the growth and programming of donor neurons. It creates a microenvironment conducive for neuronal outgrowth and promises a novel cure for neurological disorders caused by localized sites of brain damage, such as Parkinson's disease, stroke, and spinal injury. This chip is being researched in the MIT laboratories of Drs. Robert Langer and Mriganka Sur. My thesis addresses the challenges and possible strategies in commercializing this technology. The need for this treatment was evaluated in the context of current therapies available for the treatment of relevant neurological disorders. Extensive field interviews were conducted. Among other factors, the varying clockspeeds between different components of the device, the unsustainable cost structure and the emerging status of complementary technologies suggested that the development of the therapy is best pursued in collaboration with a large biopharmaceutical or medical device firm.by Anindita Dutt.S.M.M.O.T
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
ISDN2012_0279: Cortical plasticity: Cell‐specific circuits and disorders of brain development
No full textVariations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Visual Plasticity in the Auditory Pathway: Visual Inputs Induced into Auditory Thalamus and Cortex Illustrate Principles of Adaptive Organization in Sensory Systems
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