Computing Informatics Research Seminar Series

The Dynamical Response Properties of Cortical Neurons

open book on table
Seminars

As part of the School of Science and Technology's Computing Informatics Research Seminar Series, Professor Michele Giugliano, University of Antwerp presents: The Dynamical Response Properties of Cortical Neurons.

  • From: Wednesday 28 November 2018, 1 pm
  • To: Wednesday 28 November 2018, 2 pm
  • Location: Nottingham Trent University, Clifton Campus, Clifton Lane, Nottingham, NG11 8NS

Event details

As part of the School of Science and Technology's Computing Informatics Research Seminar Series, Professor Michele Giugliano, University of Antwerp presents: The Dynamical Response Properties of Cortical Neurons.

Abstract

My lab has been the first to experimentally explore and test such a hypothesis. We designed a stimulation protocol to directly probe the (dynamical) response properties of pyramidal cells of the rat neocortex in vitro, by means of patch-clamp recordings. This identifies the linear transfer function of neurons, linking (recreated) synaptic inputs to the firing probability. In the Fourier domain, this correspond to magnitude and phase of the response for progressively more rapid oscillating inputs. Interestingly, such a novel characterisation offers a deeper access to the biophysics of information processing (e.g. relevant to predict correlations) than (stationary) frequency-current curves, which are widely used to classify neuronal phenotypes.
To our surprise, not only we confirmed that pyramidal neurons can track and relay inputs varying in time faster the cut-off imposed by membrane electrical passive properties (~50 cycles/s), but we found that they do it substantially faster (up to ~200 cycles/s) than explained by their ensemble mean firing rates (~10 spikes/s). In addition, above 200 cycles/s neurons attenuate their response with a power-law relationship and a linear phase lag.
Such an unexpectedly broad bandwidth of neuronal dynamics could be qualitatively related to the dynamics of the initiation of the action potential. Interested to explore and test such a possibility, we found a first indirect confirmation of it in terms of correlation between the action potentials rapidness at onset and the neuronal bandwidth, over a large set of experiments.
A second more direct confirmation - which will conclude the presentation - came from our recent study where we applied the same protocols to in vitro human cortical (healthy) tissue, exceptionally obtained from therapeutic resective brain surgery. We found that human L2/3 cortical neurons fire much “steeper” action potentials than in rodent neurons of the same layer, and have a much more extended bandwidth reaching 1000 cycles/s, violating the predictions of existing models and opening intriguing new directions for the phylogenetics of neuronal dynamics.

All Welcome

For any enquires please contact  Mufti Mahmud and Omprakash Kaiwartya

Location details

Address:

Nottingham Trent University
Clifton Campus
Clifton Lane
Nottingham
NG11 8NS

Still need help?

+44 (0)115 941 8418