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 Wordeman

High 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 (i) One story describes unpublished ultrasensitive Hessian structured illumination microscopy that enables ultrafast and long-term super-resolution (SR) live-cell imaging.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.

“Of Mice and Men: Intrinsic Membrane Properties of Human Cortical Pyramidal Neurons” Brian Kalmbach, Ph.D. Allen Institute for Brain Science host: Nikolai Dembrow

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 Froehner

Title: TBA Nikolai Dembrow, PhD host: Stan Froehner

“Cognitive manifolds and their dynamics across states and areas” Rishidev Chaudhuri, PhD. Center for Learning & Memory The University of Texas at Austin Host: Stanley C. Froehner

“Randomness and structure in neural representations for learning” Ashok Litwin-Kumar, PhD Center for Theoretical Neuroscience Columbia University Host: Stanley C. Froehner

Canceled

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 Tuthill  

Organizing principles in developing networks and sensory populations Julijana Gjorgieva, PhD Research Group Leader, Max Planck Institute for Brain Research Assistant Professor for Computational Neuroscience, Technical University of Munich Host: Stanley C. Froehner

“Curious Intersection Between DNA Repair and Microtubule Dynamics” Linda Wordeman, Ph.D Professor Physiology & Biophysics, UW Dr. Linda Wordeman, Ph.D. uses high resolution live imaging to discover how changes in microtubule dynamics influence chromosome segregation and Chromosome INstability (CIN) in cancer cells. Dr. Wordeman will describe, mechanistically, how small changes in microtubule assembly dynamics promote CIN and reveal evidence for unexpected pathways, such as DNA damage repair, that may directly impact cellular mictrotubule dynamics.

Discovering 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. Froehner  

How 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 Froehner

Distinguished Science in Medicine Lecture Bertil Hille Thurs., April 26, 2018 NOON Hogness Auditorium.

Faces: a neural Rosetta stone Objects constitute the fundamental currency of the brain: they are things that we perceive, remember, and think about.  One of the most important objects for a primate is a face. Research on the macaque face patch system in recent years has given us a remarkable window into the detailed processes underlying object recognition. I will discuss recent findings from our lab elucidating the code for facial identity used by cells in face patches. I will then discuss how this code is used by downstream areas, as well as how the brain computes what constitutes an object in the first place. Doris Tsao Professor of Biology HHMI Investigator California Institute of Technology time: 4:00pm location: T-747, HSB host: Stan Froehner

“Elements of visual form perception” J. Anthony Movshon, PhD

Professor, Department of Ophthalmology

New Cortex.  Who dis(inhibition)?

  Brent Doiron, PhD Professor Department of Mathematics University of Pittsburgh host: Adrienne Fairhall seminar abstract: New Cortex.  Who dis(inhibition)?   It is now clear that the inhibitory circuitry within cortical networks is very complex, with multiple cell types interacting with one another and pyramidal neurons in complicated and cell specific ways.  The theoretical community has been slow to adapt to this new circuit reality, and much of our results are obtained from analysis of simpler recurrent excitatory-inhibitory circuits. Two often cited functional roles of inhibition is to: 1) stabilize the dynamics of recurrently coupled excitatory networks, and 2) enact gain control of excitatory neuron responses to a driving stimulus.  In classic excitatory-inhibitory networks mechanisms that place the network in a high gain state necessarily flirt with network instability.  We analyze how recurrent networks of pyramidal neurons (PN), parvalbumin-expressing (PV), somatostatin-expressing (SOM), and vasoactive intestinal polypeptide-expressing (VIP) interneurons compartmentalize stability and gain control through distinct inhibitory and disinhibitory pathways.  This permits a disassociation of stability and gain control in the circuit.  We further show how PC to SOM connections can be crucial in state dependent gain amplification with a simultaneous decrease of shared variability (noise correlations).  In sum, by expanding the complexity of inhibitory architecture cortical circuits can navigate distinct functional roles of inhibition through a “division of labor” with the inhibitory circuit.  This imparts a robustness to the functional operations of the circuit that is absent in the often fine-tuned reduced excitatory-inhibitory framework.

seminar: T.B.A. Ariel Rokem, PhD Senior Data Scientist eScience Institute, University of Washington host: Fairhall

Simvastatin: unexpected or logical therapy for muscular dystrophy? Nicholas P Whitehead, Ph.D. University of Washington host: Stanley C. Froehner

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 Tuthill

David L. Tirschwell, MD Attending, Neurology University of Washington

Ali Samii, MD, Professor Department of Neurology Co-Director, Movement Disorder Fellowship University of Washington

Christina J. Jones Department of Pharmacology Advisor: Dr. Randall Moon

Professor Christopher I. Petkov Laboratory of Comparative Neuropsychology Newcastle University, U.K.

David Margolis, PhD Department of Cell Biology & Neuroscience Rutgers University New Brunswick, NJ

Randall M. Chesnut, MD, FCCM, FACS, FAANS Integra Endowed Professor of Neurotrauma Department of Neurological Surgery and Orthopaedic Surgery University of Washington

Paola Betancur, Ph.D. Postdoctoral Fellow/Instructor Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine

David Ivanick, MD Resident, Neurology University of Washington

David A. Elliott, PhD Tem Leader; Cardiac Regeneration Murdoch Children’s Research Institute

Lucio G. Costa, Professor Department of Env. and Occ. Health Sciences University of Washington

Elizabeth Boyd, PhD Vice President for Research Administration Fred Hutchinson Cancer Research Center