title: Branch specific and spike-order specific action potential invasion in basal, oblique, and apical dendrites of cortical pyramidal neurons.
abstract: In neocortical pyramidal neurons, action potentials (APs) propagate from the axon into the dendritic tree to influence distal synapses. Traditionally, AP backpropagation was studied in the thick apical trunk. Here, we used the principles of optical imaging developed by Cohen to investigate AP invasion into thin dendritic branches (basal, oblique, and tuft) of prefrontal cortical L5 pyramidal neurons. Multisite optical recordings from neighboring dendrites revealed a clear dichotomy between two seemingly equal dendritic branches belonging to the same cell ("sister branches"). We documented the variable efficacy of AP invasion in basal and oblique branches by revealing their AP voltage waveforms. Using fast multisite calcium imaging, we found that trains of APs are filtered differently between two apical tuft branches. Although one dendritic branch passes all spikes in an AP train, another branch belonging to the same neuron, same cortical layer, and same path distance from the cell body, experiences only one spike. Our data indicate that the vast differences in dendritic voltage and calcium transients, detected in dendrites of pyramidal neurons, arise from a nonuniform distribution of A-type [Formula: see text] conductance, an aggregate number of branch points in the path of the AP propagation and minute differences in dendritic diameter.
authors.affiliation: University of Connecticut , Stem Cell Institute, Institute for Systems Genomics, UConn Health, Department of Neuroscience, 263 Farmington Avenue, Farmington, Connecticut 06030-3401, United States.
authors.forename: Wen-Liang
authors.initials: WL
authors.lastname: Zhou
authors.affiliation: University of Connecticut , Stem Cell Institute, Institute for Systems Genomics, UConn Health, Department of Neuroscience, 263 Farmington Avenue, Farmington, Connecticut 06030-3401, United States.
authors.forename: Shaina M
authors.initials: SM
authors.lastname: Short
authors.affiliation: University of Connecticut , Stem Cell Institute, Institute for Systems Genomics, UConn Health, Department of Neuroscience, 263 Farmington Avenue, Farmington, Connecticut 06030-3401, United States.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Rich
authors.affiliation: University of Connecticut , Stem Cell Institute, Institute for Systems Genomics, UConn Health, Department of Neuroscience, 263 Farmington Avenue, Farmington, Connecticut 06030-3401, United States.
authors.forename: Katerina D
authors.initials: KD
authors.lastname: Oikonomou
authors.affiliation: University of Connecticut , Stem Cell Institute, Institute for Systems Genomics, UConn Health, Department of Neuroscience, 263 Farmington Avenue, Farmington, Connecticut 06030-3401, United States.
authors.forename: Mandakini B
authors.initials: MB
authors.lastname: Singh
authors.affiliation: University of Connecticut , Stem Cell Institute, Institute for Systems Genomics, UConn Health, Department of Neuroscience, 263 Farmington Avenue, Farmington, Connecticut 06030-3401, United States.
authors.forename: Enas V
authors.initials: EV
authors.lastname: Sterjanaj
authors.affiliation: University of Connecticut , Stem Cell Institute, Institute for Systems Genomics, UConn Health, Department of Neuroscience, 263 Farmington Avenue, Farmington, Connecticut 06030-3401, United States.
authors.forename: Srdjan D
authors.initials: SD
authors.lastname: Antic
keywords: calcium imaging; dendritic integration; long term potentiation; prefrontal cortex; voltage imaging; voltage-sensitive dye