title: Action potential initiation in a two-compartment model of pyramidal neuron mediated by dendritic Ca2+spike.
abstract: Dendritic Ca2+spike endows cortical pyramidal cell with powerful ability of synaptic integration, which is critical for neuronal computation. Here we propose a two-compartment conductance-based model to investigate how the Ca2+activity of apical dendrite participates in the action potential (AP) initiation to affect the firing properties of pyramidal neurons. We have shown that the apical input with sufficient intensity triggers a dendritic Ca2+spike, which significantly boosts dendritic inputs as it propagates to soma. Such event instantaneously shifts the limit cycle attractor of the neuron and results in a burst of APs, which makes its firing rate reach a plateau steady-state level. Delivering current to two chambers simultaneously increases the level of neuronal excitability and decreases the threshold of input-output relation. Here the back-propagating APs facilitate the initiation of dendritic Ca2+spike and evoke BAC firing. These findings indicate that the proposed model is capable of reproducing in vitro experimental observations. By determining spike initiating dynamics, we have provided a fundamental link between dendritic Ca2+spike and output APs, which could contribute to mechanically interpreting how dendritic Ca2+activity participates in the simple computations of pyramidal neuron.
authors.affiliation: School of Electrical and Information Engineering, Tianjin University, Tianjin 300072, China.
authors.forename: Guosheng
authors.initials: G
authors.lastname: Yi
authors.affiliation: School of Electrical and Information Engineering, Tianjin University, Tianjin 300072, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Wang
authors.affiliation: School of Electrical and Information Engineering, Tianjin University, Tianjin 300072, China.
authors.forename: Xile
authors.initials: X
authors.lastname: Wei
authors.affiliation: School of Electrical and Information Engineering, Tianjin University, Tianjin 300072, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Deng
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000465:Algorithms; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000502:physiology; D003712:Dendrites / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D015640:Ion Channel Gating / Q000502:physiology; D008959:Models, Neurological; D017966:Pyramidal Cells / Q000378:metabolism / Q000502:physiology*
chemical_list: D015220:Calcium Channels; D002118:Calcium