Neuronal signal transmission in living systems is mostly realized via repetitive generation of so-called action potentials. An action potential is characterized by a fast de- and repolarization of the cellular membrane potential – an all-or-none principle - which gets propagated along nerve fibers.
Trains of action potentials build the neuronal code of the nervous system. In between nerve cells synapses convert action potentials from an input cell into analog signals and pass them to an output cell which again generates one or multiple action potentials.
Cells in the mouse retina
In the classical view, neuronal output is determined by the input a cell receives. However, the intrinsic, biophysical properties of nerve cells that shape neuronal function are quite under-explored. The capability of generating action potentials is variable in different types of nerve cells. While some cells are able to create long duration, high-frequency trains of action potentials, others can only generate single action potentials to sustained input. The biophysical properties of nerve cells that allow action potential generation are not well understood, especially whether these properties are correlated to the received inputs.
This project aims to reveal:
- The cellular properties that shape the specific output of single nerve cells in the retina
- Whether the cellular properties are optimized to the synaptic inputs these cells receive
The project ‘Biophysical diversity in retinal ganglion cells' will make use of multiple experimental techniques that allow us to measure the response of single cells in the mouse retina. We will also investigate the anatomy of retinal ganglion cells and how it contributes to the observed response patterns. Detailed computer simulations will support our analysis and will enable us to study the influence of single features of retinal ganglion cells on elicited responses.
Small difference with great significance
Potential findings of this project are not specific to retinal ganglion cells as all nerve cells follow the same all-or-none principle. Therefore, our findings will have broad implications on neuroscience in general and our understanding of neuronal signal transmission.
- P. Werginz, V. Raghuram, S.I. Fried, Tailoring of the axon initial segment shapes the conversion of synaptic inputs into spiking output in OFF-α T retinal ganglion cells. Science Advances 6 (2020).
- P. Werginz, V. Raghuram, S.I. Fried, The relationship between morphological properties and thresholds to extracellular electric stimulation in α RGCs. Journal of Neural Engineering 17 (2020).
- V. Raghuram, P. Werginz, S.I. Fried, Scaling of the AIS and somatodendritic compartments in α S RGCs. Frontiers in Cellular Neuroscience 13 (2019).