News & Events / BME Seminar Series / Current Speakers / 2020-21Lea Duncker, PhD
BME Seminar Series Spring 2021
Thursday, May 27th, 2021, 4:15-5:15 pm
This event will be held via Zoom
Host: Professor Matt Tresch
Postdoctoral Researcher
Stanford University
The Dynamics of Robustness in Motor Cortex
Genetically or anatomically targeted perturbations can provide invaluable insight into the functional role of subpopulations within neural circuits, yet their effects may be difficult to interpret. In this talk, I'll present analyses of neural population activity recorded during optogenetic excitation of cells in M1 and PMd of macaques engaged in an instructed-delay reaching task. Optical stimulation drove large changes in neural firing rates, which resulted in a large displacement of the neural state along the leading principal components of non-stimulated task activity. Although latent dynamical systems models fit to low-dimensional task activity would predict a slow decay of this perturbation, empirically, any displacement of the neural state decayed rapidly following perturbation. We hypothesized that circuit level features such as E/I balance and low-dimensional structure of the recurrent dynamics may contribute crucially to this apparent robustness to the optogenetic stimulation. To investigate this, we constructed a balanced E/I network model that expressed the low-dimensional and smooth dynamics observed in the recorded population responses during normal task-related activity. We show that stimulation of excitatory cells in the network reproduces the stimulation response features observed in neural data. Through analysis of the network model, we reveal the underlying mechanisms explaining the observed robustness. Collectively, this work offers insights into the constraints under which computation is embedded within neural populations and how modern tools for targeted manipulation of neural activity engage with neural population dynamics.
Learn more about Dr. Lea Duncker and their research here.