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Cavelli M.,University of the Republic of Uruguay | Castro S.,University of the Republic of Uruguay | Schwarzkopf N.,University of the Republic of Uruguay | Chase M.H.,Websciences International | And 3 more authors.
Behavioural Brain Research | Year: 2015

Higher cognitive functions require the integration and coordination of large populations of neurons in cortical and subcortical regions. Oscillations in the high frequency band (30-100. Hz) of the electroencephalogram (EEG), that have been postulated to be a product of this interaction, are involved in the binding of spatially separated but temporally correlated neural events, which results in a unified perceptual experience. The extent of this functional connectivity can be examined by means of the mathematical algorithm called "coherence", which is correlated with the "strength" of functional interactions between cortical areas. As a continuation of previous studies in the cat [6,7], the present study was conducted to analyze EEG coherence in the gamma band of the rat during wakefulness (W), non-REM (NREM) sleep and REM sleep.Rats were implanted with electrodes in different cortical areas to record EEG activity, and the magnitude squared coherence values within the gamma frequency band of EEG (30-48 and 52-100. Hz) were determined.Coherence between all cortical regions in the low and high gamma frequency bands was greater during W compared with sleep. Remarkably, EEG coherence in the low and high gamma bands was smallest during REM sleep.We conclude that high frequency interactions between cortical areas are radically different during sleep and wakefulness in the rat. Since this feature is conserved in other mammals, including humans, we suggest that the uncoupling of gamma frequency activity during REM sleep is a defining trait of REM sleep in mammals. © 2015 Elsevier B.V. Source


Castro S.,University of the Republic of Uruguay | Cavelli M.,University of the Republic of Uruguay | Vollono P.,University of the Republic of Uruguay | Chase M.H.,Websciences International | And 3 more authors.
Neuroscience Letters | Year: 2014

Oscillations in the gamma frequency band (mainly ≈40. Hz) of the electroencephalogram (EEG) have been involved in the binding of spatially separated but temporally correlated neural events that result in a unified perceptual experience. The extent of these interactions can be examined by means of a mathematical algorithm called "coherence", which reflects the "strength" of functional interactions between cortical areas. As a continuation of a previous study of our group, the present study was conducted to analyze the inter-hemispheric coherence of the EEG gamma frequency band in the cat during alert wakefulness (AW), quiet wakefulness (QW), non-REM (NREM) sleep and REM sleep. Cats were implanted with electrodes in the frontal, parietal and occipital cortices to monitor EEG activity. The degree of coherence in the low (30-45. Hz) and high (60-100. Hz) gamma frequency bands from pairs of EEG recordings was analyzed. A large increase in coherence between all inter-hemispheric cortical regions in the low gamma bands during AW was present compared to the other behavioral states. Furthermore, both low and high gamma coherence between inter-hemispheric heterotopic cortices (different cortical areas of both hemispheres) decreased during REM sleep; this is a pattern that we previously reported between the cortical areas of the same hemisphere (intrahemispheric coherence). In the high gamma band, coherence during REM sleep also decreased compared to the other behavioral states. In contrast, between most of the inter-hemispheric homotopic cortical areas (equivalent or mirror areas of both hemispheres), low gamma coherence was similar during NREM compared to REM sleep. We conclude that in spite of subtle differences between homotopic and heterotopic inter-hemispheric cortices, functional interactions at high frequency decrease during REM sleep. © 2014 Elsevier Ireland Ltd. Source


Grant
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 0.00 | Year: 2002

We propose to utilize the multimedia and hypertext capabilities of the World Wide Web to develop a complete, comprehensive set of resources to facilitate multi- university, interdisciplinary collaborative research dealing with any of the Complex Genetic Disorders. In order to develop these resources, a virtual private research network will be developed for one representative complex genetic disorder, namely, autism. Accordingly, this application encompasses the development of a Web-based Virtual Private Research Network for Genetic Studies of Autism (VPRN-GA) that will represent the collaborative endeavors of WebSciences and the currently constituted multi-institutional Collaborative Linkage Study of Autism (CLSA) which includes investigators at Tufts, Vanderbilt, the University of Iowa and Duke. Further expansion of the network may include eight other funded groups who are just beginning a collaboration on autism genetics via an R-13 Conference Grant (two via NIMH, and others via NINDS, NICHD, a private foundation, the Canadian MRC, a French/Swedish organization, and the British MRC and NICHD). This Phase I application focuses on developing static Web page templates for the organization and flow of information dealing with the online submission, review, discussion, evaluation, manipulation, etc., of data and documents (manuscripts); in addition, online communication and bibliographic services for the VPRN-GA will be developed. The VPRN-GA will be evaluated originally by the CLSA investigators, who will function as users/beta-testers. On the basis of the preceding, the accompanying Fast- Track Phase II application will provide for the transformation of static Web pages to a database-driven, fully functional VPRN-GA on the World Wide Web. Also included in the Phase II application is a comprehensive plan for commercialization of the software responsible for the VPRN-GA. PROPOSED COMMERCIAL APPLICATION: We anticipate that the primary commercial contribution to sustain the VPRN-GA will arise from the sale of the software that provides for an integrated set of functionalities for collaborative research on autism, complex genetic disorders, molecular biology, etc. Certain of these functionalities will be marketed as individual components, for example, the submission, review and evaluation of molecular biological images on the Web and collaborative interactions associated with these images. Additional revenue will come from sponsorships and advertising. A description of the potential sources of funding support are presented in the Phase II Appendix: Product Development Plan.


Grant
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 769.44K | Year: 2002

We propose to utilize the multimedia and hypertext capabilities of the World Wide Web to develop a complete, comprehensive set of resources to facilitate multi- university, interdisciplinary collaborative research dealing with any of the Complex Genetic Disorders. In order to develop these resources, a virtual private research network will be developed for one representative complex genetic disorder, namely, autism. Accordingly, this application encompasses the development of a Web-based Virtual Private Research Network for Genetic Studies of Autism (VPRN-GA) that will represent the collaborative endeavors of WebSciences and the currently constituted multi-institutional Collaborative Linkage Study of Autism (CLSA) which includes investigators at Tufts, Vanderbilt, the University of Iowa and Duke. Further expansion of the network may include eight other funded groups who are just beginning a collaboration on autism genetics via an R-13 Conference Grant (two via NIMH, and others via NINDS, NICHD, a private foundation, the Canadian MRC, a French/Swedish organization, and the British MRC and NICHD). This Phase I application focuses on developing static Web page templates for the organization and flow of information dealing with the online submission, review, discussion, evaluation, manipulation, etc., of data and documents (manuscripts); in addition, online communication and bibliographic services for the VPRN-GA will be developed. The VPRN-GA will be evaluated originally by the CLSA investigators, who will function as users/beta-testers. On the basis of the preceding, the accompanying Fast- Track Phase II application will provide for the transformation of static Web pages to a database-driven, fully functional VPRN-GA on the World Wide Web. Also included in the Phase II application is a comprehensive plan for commercialization of the software responsible for the VPRN-GA. PROPOSED COMMERCIAL APPLICATION: We anticipate that the primary commercial contribution to sustain the VPRN-GA will arise from the sale of the software that provides for an integrated set of functionalities for collaborative research on autism, complex genetic disorders, molecular biology, etc. Certain of these functionalities will be marketed as individual components, for example, the submission, review and evaluation of molecular biological images on the Web and collaborative interactions associated with these images. Additional revenue will come from sponsorships and advertising. A description of the potential sources of funding support are presented in the Phase II Appendix: Product Development Plan.


Xi M.,Websciences International | Chase M.H.,Websciences International | Chase M.H.,University of California at Los Angeles
Sleep | Year: 2010

Study Objectives: We previously reported that the microinjection of hypocretin (orexin) into the nucleus pontis oralis (NPO) induces a behavioral state that is comparable to naturally occurring active (rapid eye movement) sleep. However, other laboratories have found that wakefulness occurs following injections of hypocretin into the NPO. The present study tested the hypothesis that the discrepancy in behavioral state responses to hypocretin injections is due to the fact that hypocretin was not administered during the same states of sleep or wakefulness. Design: Adult cats were implanted with electrodes to record sleep and waking states. Hypocretin-1 (0.25 μL, 500μM) was microinjected into the NPO while the animals were awake or in quiet (non-rapid eye movement) sleep. Measurements and Results: When hyprocretin-1 was microinjected into the NPO during quiet sleep, active sleep occurred with a short latency. In addition, there was a significant increase in the time spent in active sleep and in the number of episodes of this state. On the other hand, the injection of hyprocretin-1 during wakefulness resulted not only in a significant increase in wakefulness, but also in a decrease in the percentage and frequency of episodes of active sleep. Conclusions: The present data demonstrate that the behavioral state of the animal dictates whether active sleep or wakefulness is induced following the injection of hypocretin. Therefore, we suggest that hypocretin-1 enhances ongoing states of wakefulness and their accompanying patterns of physiologic activity and that hypocretin-1 is also capable of promoting active sleep and the changes in various processes that occur during this state. Source

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