Daniel Denman, Allen Institute for Brain Science

Trial-by-trial spike time coordination within the mouse early visual system

Due primarily to technical limitations, little is known about the structure of spike timing across large populations of functionally-related single neurons during sensory responses. In this talk, I will discuss the development high-density extracellular electrophysiology arrays (Neuropixels) that permit such recordings across V1 and lateral geniculate (LGN) of awake, behaving mice. Using Neuropixels, we measure the reproducibility and timing variability of spike trains across repeated presentations of several types of visual stimuli – flicker, static images, and naturalistic movies. In addition to measuring single neuron spike train variability, we make a novel measurement of correlated spike time variability.We find that spike time variability is highly correlated within but not across LGN and V1 populations – consistent with the notion of dynamic local temporal reference frames. By accounting for these local correlations in timing variability, decoding of image identity from only first spike times can rival that of spike counts in V1. We also find above-chance occurrence of synchronous ensembles within V1, further supporting dynamic coordination of spike times within V1 networks at the sub-2 msec timescale.  

 

Organized by

Jens Kremkow/Margret Franke

Location

BCCN Berlin, lecture hall, Philippstr. 13 Haus 6, 10115 Berlin