title: Synapse distribution suggests a two-stage model of dendritic integration in CA1 pyramidal neurons.
abstract: Competing models have been proposed to explain how neurons integrate the thousands of inputs distributed throughout their dendritic trees. In a simple global integration model, inputs from all locations sum in the axon. In a two-stage integration model, inputs contribute directly to dendritic spikes, and outputs from multiple branches sum in the axon. These two models yield opposite predictions of how synapses at different dendritic locations should be scaled if they are to contribute equally to neuronal output. We used serial-section electron microscopy to reconstruct individual apical oblique dendritic branches of CA1 pyramidal neurons and observe a synapse distribution consistent with the two-stage integration model. Computational modeling suggests that the observed synapse distribution enhances the contribution of each dendritic branch to neuronal output.
authors.affiliation: Department of Neurobiology and Physiology, Northwestern University, Evanston, IL 60208, USA.
authors.forename: Yael
authors.initials: Y
authors.lastname: Katz
authors.forename: Vilas
authors.initials: V
authors.lastname: Menon
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Nicholson
authors.forename: Yuri
authors.initials: Y
authors.lastname: Geinisman
authors.forename: William L
authors.initials: WL
authors.lastname: Kath
authors.forename: Nelson
authors.initials: N
authors.lastname: Spruston
mesh_terms: D000818:Animals; D003712:Dendrites / Q000648:ultrastructure*; D006624:Hippocampus / Q000033:anatomy & histology / Q000166:cytology*; D006801:Humans; D008854:Microscopy, Electron; D008959:Models, Neurological; D016571:Neural Networks, Computer; D009434:Neural Pathways / Q000648:ultrastructure*; D009474:Neurons / Q000648:ultrastructure*; D013569:Synapses / Q000648:ultrastructure*