Influence of Dendritic Morphology on Single Neuron Arithmetic

Pyramidal cells are the most abundant type of neurons in the cerebral cortex. Their activity has been associated with higher cognitive and emotional functions. Pyramidal cells have a characteristic structure, consisting of a triangularly shaped soma where from two complex dendritic trees and a long bifurcated axon extend. All the morphological components of the pyramidal neurons exhibit significant variability across different brain areas and layers. Pyramidal neurons receive numerous synaptic inputs on the basal, oblique and tuft dendrites, whose integration in space and time can result in the generation of local dendritic spikes. Different modes of the combined subthreshold synaptic effects are observed: linear, when integration is the sum of individual responses, and nonlinear, when synaptic inputs are integrated in a sigmoid or power function. While both experimental and theoretical work has been performed to characterize the arithmetic of synaptic summation in pyramidal neurons, the role of dendritic morphology in this process remains elusive.