UNIVERSITY OF HERTFORDSHIRE
             COMPUTER SCIENCE RESEARCH COLLOQUIUM

                            presents

     
	         "Strong but sparse inputs determine neuronal
                    output via dendritic spikes"
	

                       Dr. Arnd Roth
                (University College London)

                       22 November 2023 
                        13:00 -14:00 
                          Room 1A161

                  Everyone is Welcome to Attend
				  
				            

                              

Abstract:

The dendrites of neocortical pyramidal neurons are excitable. However, it is unknown how synaptic inputs engage nonlinear dendritic mechanisms during sensory processing in vivo, and how they in turn influence action potential output. We provide a quantitative account of the relationship between synaptic inputs, nonlinear dendritic events, and action potential output. We developed a detailed pyramidal neuron model constrained by in vivo dendritic recordings. We drive this model with realistic input patterns constrained by sensory responses measured in vivo and synaptic connectivity measured in vitro. We show mechanistically that under realistic conditions in vivo, dendritic Na+ and NMDA spikes are the major determinants of neuronal output. We demonstrate that these dendritic spikes can be triggered by a surprisingly small number of strong synaptic inputs, in some cases even by single synapses. We predict that dendritic excitability enables the 1% strongest synaptic inputs of a neuron to control the tuning of its output. Active dendrites therefore allow smaller subcircuits consisting of only a few strongly connected neurons to achieve selectivity for specific sensory features.


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Hertfordshire Computer Science Research Colloquium
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