On the Speed of Neuronal Populations
von Tūreiti Keith
Datum der mündl. Prüfung:2017-03-07
Erschienen:2017-10-10
Betreuer:Dr. Andreas Neef
Gutachter:Prof. Dr. Walter Stühmer
Gutachter:Prof. Dr. Fred Wolf
Gutachter:Prof. Dr. Jörg Enderlein
Gutachter:Prof. Dr. Ulrich Parlitz
Gutachter:Prof. Dr. Florentin Wörgötter
Dateien
Name:Thesis_to_publish_v1.pdf
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Zusammenfassung
Englisch
This thesis presents novel results in the areas of closed loop electrophysiology and neuronal population coding. This work begins by presenting the first known attempt to control the spike rate of a neuron or neurons using a feedback controller that drives a stochastic photostimulus. Using this controller, in vitro experiments were performed that look into the response of a population of cortical neurons to subtle changes in the mean of a correlated, stochastic photostimulus. This work then presents a numerical examination of how stimuli targeting specific elements of a neuron's structure, referred to as "subcellular targeting," affect the response speed of the population, the action potential onset of its constituent neurons and their effective passive bandwidth. The results presented here demonstrate that it is indeed possible to regulate the spike rate of a neuron or neurons using a feedback controller that scales the mean and variance of a correlated, stochastic photostimulus. Furthermore, using this controller, trial-based experiments were implemented in the laboratory. These demonstrate that an in vitro population of cortical neurons can provide robust albeit slow responses to subtle changes in the mean of a correlated, stochastic photostimulus. Finally, in numerical experiments, mean modulated, correlated, stochastic photostimuli were applied to either the entire cell, the soma or the basal dendrites of a morphologically realistic constituent neuron. The results show that this subcellular targeting of constituents produces a faster population response when the soma is targeted, followed by the basal dendritic then the global target. Although a strong statistical argument is difficult to make, the results do suggest congruent increases in the response speed of a neuronal population under subcellular targeting, the onset rapidness of its constituent neurons and their passive bandwidths.
Keywords: closed loop; optogenetics; population response; pid; targeted stimulus