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Identifier 000426283
Title Anti-coincidence detection in the dendrites of human layer 2/3 neocortical neurons
Alternative Title Ανίχνευση αντισύμπτωσης στους δενδρίτες των ανθρωπίνων νευρώνων επιπέδου 2/3 του νεοφλοιού
Author Σούρσου, Γεωργία
Thesis advisor Ποϊράζη, Παναγιώτα
Reviewer Σιδηροπούλου, Κυριακή
Τσαμαρδινός, Ιωάννης
Abstract The purpose of this thesis is to implement a biophysical detailed single neuron model to investigate the active properties that underlie the dendritic computations in human layer 2 and 3 (L2/3) cortical neurons with the usage of Boolean Algebra. Due to evolutionary pressure, the human cortex over periods of years gained two major properties. First, it is extraordinary thick, especially the L2/3 supragranular layers, and, second, it has vast dendritic trees receiving numerous synaptic inputs. The experimental data to fit the model were produced by dual somato-dendritic patch clamp and two-photon imaging from Dr. Albert Gidon (Larkum Lab, Humboldt Universität, Berlin). They observed a fast dendritic calcium action potential (dCaAP), with previously unknown active properties. This dendritic action potential contributes to the repertoire of transformations from synaptic inputs to action potentials (APs) in human L2/3 neurons. The dendritic activation function, namely, the amplitude of those dCaAPs’ as a function of the intensity of the current injection in the dendrite, was sharply tuned to an optimal input and progressively suppressed for stronger inputs. This indicated that dendrites of human L2/3 neurons are intrinsically capable of computing anti-coincidence functions like the XOR. To expand this computational modeling approach, it was investigated under which conditions (such as number and type of synaptic inputs) other activations functions from Boolean Algebra can be implemented. When implementing the coupled mode, meaning that dendritic response initiated somatic spikes, the latter was able to reproduce all logical operations except the negative ones. Interestingly, when implementing the uncoupled one with only the dendritic response, all logical operations including the negative ones were reproduced. These suggest that dendrites in human cortical neurons expand the computational power of neurons even to perform negative computations and provide evidence for a dendrite-centered theory of neuronal function. Thus, is important to investigate the capacity of these dendritic computations. The model also investigates what is the contribution of apical and basal dendrites of the L2/3 single neuron when only the basal sub-region is stimulated and under specific conditions of N- methyl-D-aspartate receptor (NMDA) spiking activity. Future work involves further investigation of the computation and cellular substrate, e.g. spines and morphological features of the human cortical neurons, towards a more thorough functional application of this novel dendritic activation mechanism to human cognition.
Language English
Subject Ανίχνευση αντισύμπτωσεις
Ανθρώπινοι φλοιώδεις νευρώνες επιπέδου 2/3
Ισχύ δενδριτικού υπολογισμού
Κορυφαίοι κ βασικοί δενδρίτες
Λογικές πύλες
Υποδοχέας Ν-μεθυλο-D-ασπαρτικού οξέος
Issue date 2019-12-11
Collection   Faculty/Department--School of Medicine--Department of Medicine--Post-graduate theses
  Type of Work--Post-graduate theses
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