CBR Seminar: Encoding of virtual reality locomotion kinematics in cerebellar neural activity Event as iCalendar

01 September 2016

10 - 11:30am

Venue: CBR Seminar Room 501-505

Location: FMHS

Host: Dr Suresh Muthukumaraswamy

Contact info: Frankie Favero

Contact email: f.favero@auckland.ac.nz

Simon Schultz


Abstract

Encoding of virtual reality locomotion kinematics in cerebellar neural activity
 
Simon R Schultz, Centre for Neurotechnology & Dept of Bioengineering, Imperial College London
 
The cerebellum has a well-established role in the control of balance and locomotion, and “walking ataxia” is a key characteristic of cerebellar damage. The cerebellar cortical circuit has also been described in great detail. How this circuit supports locomotor behaviour, however, is not yet well understood.
 
Much of our knowledge of the cerebellar role in locomotion comes from seminal papers in which the activity of cerebellar neurons in the cat was recorded while cats were walking on a treadmill. While increases of firing rate during locomotion were observed, and many cells fired in phase with the stepping cycle, little to no tuning to speed of locomotion was observed.

Given the prevalence of locomotor speed tuning elsewhere in the brain (entorhinal and visual cortex being two documented examples), we found this surprising. We therefore recorded cerebellar neuronal activity using silicon multi-electrode arrays, in head-fixed mice performing a locomotion task in “virtual reality” on an air-levitated polystyrene ball. 

To complete the study, the team built an optimal linear decoder, which weights the output of individual neurons, and passes them through a rectifying nonlinearity. This decoder was able to reconstruct the time course of the locomotor speed using a simple, biophysically plausible mechanism, and needed surprisingly few cells to do so – locomotor speed can be accurately decoded from any five typical randomly chosen neurons in our recorded ensemble.

In the talk Dr Schultz will describe the rich response characteristics, including prevalent tuning to locomotion speed, yaw and step phase that were observed across all cell types.


About the speaker

Dr Simon R Schultz is Reader in Neurotechnology, and Director of the Centre for Neurotechnology at Imperial College London.


He trained in physics and electrical engineering (at Monash and Sydney Universities), before completing a DPhil in computational neuroscience at Oxford University in 1998. This was followed by postdoctoral stints in experimental neuroscience with Tony Movshon at New York University, and Michael Häusser at UCL. He joined Imperial College in 2004, and has led the development of Imperial’s critical mass in the area of Neurotechnology. 

Simon is widely known for work on neural coding. He has been amongst the pioneers in the use of two-photon imaging to study neural coding and has also worked on large-scale computational models of cortical circuits. 

Dr Schultz has been the PI or Co-PI of grants totalling over £20M, including being the PI for Imperial College of the EU FP7 Marie-Curie Training Network “NETT - Neural Engineering Transformative Technologies”, and PI of the £10M EPSRC Centre for Doctoral Training in Neurotechnology for Life and Health. 

A Fellow of the Institute of Engineering and Technology (FIET), Simon also acts as Associate Editor for the Journal of Computational Neuroscience.


RSVP is essential for catering. Please confirm your attendance here.


CBR Seminars are supported by the Neurological Foundation of New Zealand.