Seminars
How plants conquer the space: the cell’s flying plates
Plant cytokinesis is orchestrated by a specialized structure, the phragmoplast. The phragmoplast first occurred in representatives of Charophyte algae and then became the main division apparatus in land plants. Major cellular activities, including cytoskeletal dynamics, vesicle trafficking, membrane assembly, and cell wall biosynthesis, cooperate in the phragmoplast under the guidance of a complex signaling network. My research focuses on the self-organization processes that govern phragmoplast functions. I will give a general overview of plant cytokinesis, and present our recent data on the gamma-tubulin independent microtubule nucleation by the plant-specific protein MACERATOR and a conserved member of TPX2 protein family.
Andrei Smertenko, Ph.D. Assistant Professor, Molecular Plant Sciences Washington State University host: Linda WordemanHigh spatiotemporal resolution, three-dimension fluorescence imaging of biological samples in vivo
Dr. Liangyi Chen Professor Laboratory of Cell Secretion and Metabolism Institute of Molecular Medicine, Peking University, Beijing, China Host: Bertil Hille Abstract: I will give two stories. (i) One story describes unpublished ultrasensitive Hessian structured illumination microscopy that enables ultrafast and long-term super-resolution (SR) live-cell imaging. At a photon dose one order less than point-scanning microscopy, Hessian-SIM has achieved 88-nm and 188-Hz spatial-temporal resolution for live cells imaging and lasted thousands of images without artifacts. Operating at 1 Hz, Hessian-SIM enables hour-long, time-lapse SR imaging with mitigatable photobleaching, highlighting the possibility of achieving SR imaging with commonly used fluorophores for an unlimited period of time. (ii) The second story is our recent Nature Methods paper, our invention of the fast high-resolution miniature two-photon microscope for brain imaging in freely-behaving mice at the single-spine level. With a headpiece weighing 2.15 g and a new type of hollow-core photonic crystal fiber to deliver 920-nm femtosecond laser pulses, the mini-microscope is capable of imaging commonly used biosensors at high spatiotemporal resolution (0.64 μm laterally and 3.35 μm axially, 40 Hz at 256 × 256 pixels). It compares favorably with benchtop two-photon microscopy and miniature wide-field fluorescence microscopy in the structural and functional imaging of Thy1-GFP- or GCaMP6f-labeled neurons. Further, we demonstrate its unique application and robustness with hour-long recording of neuronal activities down to the level of spines in mice experiencing vigorous body and head movements or engaging in social interaction.Evolution and brain computation
I will introduce our work towards identifying principles of brain function and computation, focused on using comparative approaches and exploiting unusual model systems (reptiles, cephalopods) to study sleep, texture perception and cerebral cortex evolution. Gilles Laurent, PhD, DVM Director Max Planck Institute for Brain Research http://www.brain.mpg.de/home/ 4:00 PM Location: T-739, HSB host: Stan FroehnerCanceled
Dr. Bastian’s seminar will be rescheduled for a later date.
Learning and Relearning Movement
Human motor learning depends on a suite of brain mechanisms that are driven by different signals and operate on timescales ranging from minutes to years. Understanding these processes requires identifying how new movement patterns are normally acquired, retained, and generalized, as well as the effects of distinct brain lesions. The lecture focuses on normal and abnormal motor learning and how we can use this information to improve rehabilitation for individuals with neurological damage Amy Bastian, Ph.D. Professor of Neuroscience Johns Hopkins University Host: John TuthillDiscovering Structure in Neural and Behavioral Data
Scott Linderman, PhD Department of Statistics Columbia University Abstract: New recording technologies are transforming neuroscience, allowing us to precisely quantify neural activity, sensory stimuli, and natural behavior. How can we discover simplifying structure in these high-dimensional data and relate these domains to one another? I will present my work on developing statistical tools and machine learning methods to answer this question. With two examples, I will show how we can leverage prior knowledge and theories to build models that are flexible enough to capture complex data yet interpretable enough to provide new insight. Alongside these examples, I will discuss the Bayesian inference algorithms I have developed to fit such models at the scales required by modern neuroscience. First, I will develop models to study global brain states and recurrent dynamics in the neural activity of C. elegans. Then, I will show how similar ideas apply to data that, on the surface, seem very different: movies of freely behaving larval zebrafish. In both cases, these models reveal how complex patterns may arise by switching between simple states, and how state changes may be influenced by internal and external factors. These examples illustrate a framework for harnessing recent advances in machine learning, statistics, and neuroscience. Prior knowledge and theory serve as the main ingredients for interpretable models, machine learning methods lend additional flexibility for complex data, and new statistical inference algorithms provide the means to fit these models and discover structure in neural and behavioral data. Host: Stanley C. FroehnerHow and why are the currents of CaV1.1 calicum channels curtailied in skeletal muscle?
The presentation will include structure-function studies on CaV1 channels and analyses of the role of the calcium current in muscle fiber type specification and neuro-muscular junction formation using various mouse models. Bernhard Flucher, PhD Professor Department of Physiology and Medical Physics Medizinische Universität Innsbruck host: Stan FroehnerProfessor, Department of Ophthalmology
Professor, Department of Neuroscience and Physiology
Thursday, May 10, 2018 2:00 p.m. T-639 HSB