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Ongoing Projects

Investigating the response of CNS neurons to electric and magnetic stimulation
NIH-Prime Award 1R01NS110575-01, 2019-2023, partner (PI Shelley Fried)

Our long-term goals are to better understand the response of neurons to artificial stimulation, and, to use this knowledge to develop new and more effective strategies for stimulating non- or improperly-functioning neurons of the CNS. The development of models that comprehensively and accurately predict the response of neural populations to electric stimulation has proven challenging, in part because of the significant morphological differences that can exist even between nearby cells, and, a lack of understanding as to how such differences shape each cell’s response to stimulation.

http://friedlab.mgh.harvard.edu/ 

 

Upper threshold phenomenon and its impact on neuroprostheses
Stand-alone project awarded to Frank Rattay, Austrian Science Fund (FWF), 2017-2021

Recently, a biophysical principle was proposed that should explain the inhibition of action potentials observed in the soma of neurons if strong cathodic stimulation is applied with micro-electrodes. It was suggested that the strong electric field causes an outflow of sodium ions, which in turn prevents action potential generation. It is, however, unclear if this effect of current reversal (also Upper threshold phenomenon) is of practical relevance, since there is an alternative well-described biophysical explanation. Within the scope of this project detailed computational models and experimental validation should give deeper insights in the how and why action potential generation is facilitated or prevented during external microstimulation.

Abstract (german)

 

Experimental identification of calcium current reversal in retinal bipolar cell terminals
Erwin Schrödinger Fellowship awarded to Paul Werginz, Austrian Science Fund (FWF), 2017-2020

Electrical stimulation of neurons is employed in the field of neuroprosthetics to artificially generate or block neural activity. Such an activation of retinal neurons in a controlled way is one possibility to restore a rudimentary kind of vision in blind patients. A general approach for coordinated electrical stimulation of retinal neurons, however, has not been found so far. Especially the dynamics of calcium channels in bipolar cells which are necessary for synaptic activity in the retina are not well understood. Therefore, in the course of this project multiple electrophysiological experiments in mammalian retina in-vitro will be performed in order to investigate the detailed properties of these ion channels during electrical stimulation.

Abstract (german) & http://friedlab.mgh.harvard.edu/

Completed Projects (since 2000)

switchBoard - In the eye of the observer: Visual processing at the heart of the retina
EU Innovative Training Networks EU 674901, 2015-2019, partner (PI Thomas Euler)

Selective cell stimulation with retinal implants
FWF 27335, 2014-2017

Augmentation of residual neural control by non-invasive spinal cord stimulation to modify spasticity in spinal cord injured people
Vienna Science and Technology Fund (WWTF), 2011-2015, partner (PI Winfried Mayr)

Human cochlear nerve model
FWF 21848, 2009-2013

Neuromodulation method for improving mobility in paraplegics
FWF L512, 2008-2011

Electrical stimulation of the denervated human thigh
FWF P18848, 2006-2009

Modeling LLPG activity in incomplete SCI subjects
FWF P15469, 2002-2006