Morpho-electric and computational properties of three types of human hippocampal CA1 pyramidal neurons

Abstract

ABSTRACTHippocampal pyramidal neuron activity underlies episodic memory and spatial navigation. Although extensively studied in rodents, extremely little is known about human hippocampal pyramidal neurons, even though human hippocampus underwent strong evolutionary reorganization and shows lower theta rhythm frequencies. To test whether biophysical and computational properties of humanCA1pyramidal neurons can explain observed rhythms, we map the morpho-electric and computational properties of individualCA1pyramidal neurons in human, non-pathological hippocampal slices from neurosurgery. HumanCA1pyramidal neurons have extensive dendrites and resonate at 2.9 Hz, optimally tuned to human theta frequencies. Morphological and biophysical properties reveal three cell types with distinct dendrite bifurcations and physiology. Data-driven biophysical models show that humanCA1pyramidal neurons use i) computationally independent dendritic compartments, ii) preferential routing of electrical activity towards soma or dendritic tree and iii) non-linear input-output transformations. Across cell types, morpho-electric properties consistently increase computational richness in humanCA1pyramidal neurons.TeaserHumanCA1pyramidal neurons have large and intricate morphologies, which translates to complex computational properties.