2015 — 2020 |
Raman, Baranidharan |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Career: Neural Dynamics, Olfactory Coding and Behavior
This project focuses on how neural activity in relatively simple invertebrates encodes information about an odorant?s identity and intensity, in a manner that is robust to variations in the intensities and background contexts in which sensory stimuli can be encountered. Electrophysiological, computational and behavioral approaches are combined in this effort to determine the basic principles of olfactory information processing. The identified biological olfaction principles will also lead to development of novel signal-processing algorithms for artificial olfaction, i.e. for electronic noses used in many non-invasive chemical-sensing applications.
The technical goals of the project are to determine how response dynamics at the single neuron and population levels maintain/alter olfactory invariance and examine correlations between physiology and odor-driven behavior. An integrative approach will take advantage of the rich repertoire of genetic tools available in the fruit fly (Drosophila melanogaster) to study single neuron dynamics, and combine it with multi-unit electrophysiological approaches that are well established in locusts (Schistocerca americana) to examine neural circuit dynamics. The biological data will be used to develop experimentally constrained models of olfactory signal processing to gain mechanistic insights and facilitate development of bio-inspired algorithms for an electronic nose. This research will reveal how dynamic patterns of neural activity allow the olfactory system to represent odorants in a background- and concentration-invariant manner. Examination of the interactions between an external stimulus and intrinsic neural dynamics is also expected to inform a better general understanding of dynamical neuronal networks. Data and analytical approaches obtained from the proposed work will be used to develop new neural engineering modules for undergraduate and graduate courses and thereby enhance the existing biomedical engineering curriculum. Furthermore, a K-12 teachers professional development workshop: ?Where biology meets engineering? will be created to provide middle- and high-school teachers with content and tools to offer their students a meaningful exposure to the interdisciplinary nature of science education.
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2017 — 2020 |
Raman, Baranidharan Ching, Shinung [⬀] |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Crcns Research Proposal: Collaborative Research: Studying Competitive Neural Network Dynamics Elicited by Attractive and Aversive Stimuli and Their Mixtures
This award supports basic research regarding the question of how networks in the brain allow odors to be detected and perceived. Such a question is of fundamental interest in neuroscience because responding to odors or scents is one of the most basic ecological abilities exhibited across different animal species. Further, responses to odors are highly dependent on context. For example, certain smells may create both attractive and repulsive reactions, depending on small differences in dilution or whether they are encountered alone or as components in a cocktail. Thus, studying how the brain processes odors can provide important clues regarding how animals and humans sense and perceive in complex environments. In seeking such understanding, this project uses a unique combination of methods from neuroscience, mathematics, and engineering. Brain activity from two different animal species are recorded during experiments in which odors are presented in isolation and in mixtures. Subsequently, data analysis and mathematical modeling is used to identify brain activity patterns that distinguish the reaction of the animals to the odors in question. Hence, the project uncovers how particular brain networks transform and transmit odor information in a way that is central to the sense of smell. To broaden the impact of these studies, the project includes the development of a summer internship in sensory neural engineering, intended to allow undergraduate and high school students to learn about and experience how different academic disciplines contribute to future brain science.
The extent to which sensory networks amplify or suppress perceived differences in odor valence remains a fundamental, unanswered question in sensory neuroscience. The overarching hypothesis of this project is that indeed, there exists a well-defined set of transformations, governed by neuronal dynamics, which map sensory network activity to behavior. Specifically, the project will determine: (a) How neural networks enable the formation of time-varying neural activation patterns, or, trajectories, in response to sensory stimuli, (b) The mapping from trajectories to behavioral outcome, and (c) The commonality of this mapping across species. The research goals use an interdisciplinary approach combining sensory systems neuroscience in two species, locusts (Schistocerca americana) and round worms (C. elegans), with computational modeling and dynamical systems theory. Neural and behavioral responses are recorded from animals receiving nominally attractive and aversive odors, and these data inform computational models of the sensory networks and ensuing behaviors. The models generate predictions on how behavioral responses might be modulated by a change in selectivity, or background state. The latter is tested through a paradigm wherein animals are systematically fed or starved, thus shifting their response dynamics on the aversive-attractive spectrum. Subsequently, model-based sensitivity analyses is used to predict mixture response curves and paradoxical mixtures (e.g., two aversive stimuli that when mixed, elicit an attractive response). These predictions are tested by delivering component stimuli in systematic ratios. Thus, the overall methodology combines physiological experiments with new systems-level analysis in an integrated, multidisciplinary modeling-theory loop.
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2017 — 2020 |
Robinson, Gene Duncan, Ian Ben-Shahar, Yehuda [⬀] Raman, Baranidharan |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Neuronex Technology Hub: Advancing Neuronal and Genetic Approaches to Animal Behavior Research
Neuroscience is one of the most prominent areas of modern biomedical research, but its impact on other fields, particularly those related to environmental and organismal biology, has been limited. This is because an increasing proportion of neuroscience research has been concentrated on just a few "model" animal species, such as the mouse and fruit fly, for which powerful genetic tools have been developed to manipulate their genomes. This focus stands in stark contrast to the early days of neuroscience research, in which a broader sampling of biodiversity led to important discoveries. Prominent examples include the discovery of how neurons become activated in the squid and how long-term memory is established in a marine slug. The primary goal of this proposal is to increase the diversity of animal species that can be used to advance neuroscience research by developing and applying modern neurogenetic tools for observing and manipulating neuronal activity in any animal species. As a proof-of-principle, state-of-the-art tools are developed for the honey bee and the American grasshopper. In addition to having immediate impact on basic neuroscience, the project has impact on applied research, as these two selected species are important pests and pollinators, respectively. The new tools and research findings from the proposed work is disseminated to the research community via NSF-funded initiatives to increase species diversity in genetic studies, and national and international workshops. The dissemination efforts include the development of an annual intensive summer course at Washington University that entails both lectures and hands-on experiences for organismal biologists who are interested in incorporating modern neuroscience and genetic tools into their research programs. Additional educational and training opportunities served by the project include public neuroscience outreach efforts in the St. Louis region, training of postdoctoral fellows, as well as mentoring of graduate, undergraduate, and high school students in hypothesis-driven neuroscience research.
The lack of species diversity in modern neuroscience research restricts the applicability and interpretations of general neurobiological principles in the context of organismal, ecological, and evolutionary questions. Therefore, the primary goal of this proposal is to increase animal species diversity in systems and behavioral neuroscience research by enabling easy adoption of universal genetic and transgenic tools for monitoring and manipulating neuronal activity in any animal species, with a specific emphasis on insects. The proposed approach is comprised of two steps. First, Cas9/CRISPR-dependent genome editing is used to replace the non-essential gene white with a DNA cassette that includes an eye-specific red fluorescent protein (RFP) flanked by two directional phiC31-integrase attP sites, enabling rapid screening of both white eye-color and RFP expression as markers of successful germline transformation. Second, the efficient phiC31-Integrase reaction is used to replace the RFP cassette with a transgene of choice. As a proof-of-principle, transgenic lines that express the Ca2+ reporter GCaMP6 in defined neuronal populations in the honey bee Apis mellifera and the American grasshopper Schistocerca americana are generated and tested for feasibility. By enabling the use of modern genetic tools to enhance neuroscience research in these two economically important insect species, which also serve as important models for basic organismal biological research, the proposed project is likely to have broad impact relevant to diverse research fields, including agriculture, neuroethology, animal behavior, pest ecology, and behavioral neuroscience. This NeuroTechnology Hub award is part of the BRAIN Initiative and NSF's Understanding the Brain activities.
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2022 — 2023 |
Raman, Baranidharan |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Conference: Chemical Sensing Innovation: Harnessing Recent Advances in Biological, Physical, Chemical and Data Sciences For Engineering Next Generation Electronic Noses
This project will organize and host a workshop to identify the parameters and sub-elements for a potential Convergence Accelerator track related to chemical sensing. The core of this effort is to engage and bring together scientists and user communities together to envision how best to leverage the advances in chemical science sensing research, focusing especially on the convergence between areas related to biological olfaction, material science, bioelectronics and manufacturing, genetic engineering, AI/ML/Data Science, to define use inspired approaches that could lead to development of sensors for several applications. including diagnosis of diseases, homeland security, environmental monitoring. The proposed workshop is expected to help identify pilot efforts for a track in that it can facilitate development of several applications, including diagnosis of diseases, homeland security, environmental monitoring. These insights, if implemented in a track, could have transformative impacts on the translation of scientific research related to olfactory circuits into portable detectors/sensors with high selectivity and sensitivity. <br/><br/>This workshop effort plans include online ideation, virtual meetings of stakeholders, and in-person synthesis. A particular focus will be on bringing together researchers and user communities from different segments including climate change and environmental monitoring, homeland security, agriculture. Representatives from different federal agencies as well as industry will also be part of the workshop organizing teams. This will bring in perspectives from experts in disparate fields and user communities and this, in turn, will lead to identification of key areas where opportunities for translational research exists at the intersection of many fields such as biological olfaction, neuromorphic computing, and materials sciences.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
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