Event Details:
Continue the conversation: Join the speaker for a complimentary dinner in the Theory Center (second floor of the neurosciences building) after the seminar
Revealing geometry of neuronal population dynamics using cortex-wide volumetric recording of neuroactivity at cellular resolution
Abstract
Understanding how sensory information is represented, processed, and leads to generation of complex behavior is the major goal of systems neuroscience. However, the ability to detect and manipulate such large-scale functional circuits has been hampered by the lack of appropriate tools and methods that allow parallel and spatiotemporally specific manipulation of neuronal population activity while capturing the dynamic activity of the entire network at high spatial and temporal resolutions.
Our lab has consistently pushed the limits on speed, volume size, and depth at which neuronal population activity can be optically recorded at cellular resolution. Amongst others have demonstrated whole-brain recording of neuroactivity at cellular resolution in small model systems as well as more recently near-simultaneous recording from over 1 million neurons distributed across both hemispheres and different layers of the mouse cortex at cellular resolution.
While our capability to record from ever increasing number of neurons has increased over the years the widespread application of dimensionality reduction tools implies that neural dynamics can be approximated by low-dimensional “latent” signals reflecting neural computations. However, what would be the biological utility of such a redundant encoding scheme, and what is the appropriate resolution and scale of recording to understand brain function? Imaging neural activity at cellular resolution and near-simultaneously across mouse cortex, we have recently found unbounded scaling of dimensionality of neuronal population activity with neuron number in populations sizes of up to one million neurons. Our data suggests that while half of the neural variance is contained within about sixteen dimensions that are correlated with behavior, the majority of the reliable dimensions which collectively account for the other half of total neuronal variance do not have any immediate behavioral or sensory correlates. The activity patterns underlying these higher dimensions are fine-grained and cortex-wide, highlighting that large-scale, cellular-resolution recording is required to uncover the full substrates of neuronal computations.
Alipasha Vaziri
The Rockefeller University
Dr. Vaziri is the Founder & Director of the Miller Brain Observatory (MBO) and Professor and the Head of Laboratory of Neurotechnolology and Biophysics at The Rockefeller University. His studies focus on how large-scale dynamics of neuronal networks are related to brain functions and behavior. To do so, his lab has developed new high-speed optical technologies that have consistently pushed the boundaries on spatial and temporal resolution, as well as volume size and depth at which the dynamic interactions of neuronal populations is obtained in behaving animals. He holds a Ph.D. in Physics from the University of Vienna in quantum optics where he worked on the implementation of various quantum information and quantum communication protocols. He completed his postdoctoral training at the National Institute of Standards and Technology and the University of Maryland working on quantum superposition states in Bose Einstein Condensates. He subsequently worked as a research scientist at HHMI Janelia Research Campus.
Hosted by Sabrina Liu (see profile below)
About the Mind, Brain, Computation, and Technology (MBCT) Seminar Series
The Stanford Center for Mind, Brain, Computation and Technology (MBCT) Seminars explore ways in which computational and technical approaches are being used to advance the frontiers of neuroscience.
The series features speakers from other institutions, Stanford faculty, and senior training program trainees. Seminars occur about every other week, and are held at 4:00 pm on Mondays at the Cynthia Fry Gunn Rotunda - Stanford Neurosciences E-241.
Questions? Contact neuroscience@stanford.edu
Sign up to hear about all our upcoming events
Related Event
