The progress of neuroscientific research is linked to the development of technologies able to interface with the complexity of neural circuitry. Remarkable advances in this direction have been achieved in the past decades and it is now possible to optically control the neural activity of genetically targeted cells with techniques known as optogenetic stimulation. The combination of optogenetic stimulation methods with electrophysiological recordings and advanced optical imaging is leading to promising approaches aiming at obtaining information on spiking activity, morphology and genetic identity of the many constituents of neural networks.This PhD research project focussed on the development of an experimental tool to exploit this possibility combining micro-electrode array (MEA) electrophysiological recordings with a custom two-photon microscope and optogenetic stimulation system based on a μLED array. This thesis reports on the construction, validation and application of this tool, that was employed in retinal recordings to link the precisely-timed spike signals detected by the MEA with the anatomical and genetic identity of the spiking neurons.The combination of large-scale MEA recordings with spatio-temporal μLED optogenetic stimulation led to a novel method to link anatomy to functional and genetic identity in genetically-targeted retinal ganglion cells (RGCs) with a large scale approach. This method is a versatile approach that can be applied to characterise the many molecular types of RGCs. The integration of two-photon imaging and MEA recordings proved to be more arduous, yet applicable. Retinal ganglion cells were imaged in two-photon mode while mounted on the MEA and electrophysiological identification of spiking units was demonstrated notwithstanding large laser-induced artifacts.Optimisation of the system will allow to fully exploit the advantages offered by non-linear excitation.
|Date of Award||10 Feb 2017|
- University Of Strathclyde
|Sponsors||EPSRC (Engineering and Physical Sciences Research Council)|
|Supervisor||Keith Mathieson (Supervisor) & Erling Riis (Supervisor)|