Dichotomy of Action-Potential Backpropagation in CA1 Pyramidal Neuron Dendrites

• DOI: 10.1152/jn.2001.86.6.2998
• Publication Date: 2017-12-21T06:06:05Z
• Authors: Nace L. Golding; William L. Kath; Nelson Spruston
• Keywords: Dendritic spike; Apical dendrite; Dendrite (mathematics); Action potential; Pyramidal cell

In hippocampal CA1 pyramidal neurons, action potentials are typically initiated in the axon and backpropagate into dendrites, shaping integration of synaptic activity influencing induction plasticity. Despite previous reports describing action-potential propagation proximal apical extent to which invade distal dendrites neurons remains controversial. Using paired somatic dendritic whole cell recordings, we find that 280 μm from soma, single backpropagating exhibit <50% attenuation their amplitude soma. However, recordings 300 most cells backpropagated either strongly (26–42% attenuation; n = 9/20) or weakly (71–87% 10/20) with only one exhibiting an intermediate value (45% attenuation). experiments combining dual calcium imaging, amount influx triggered by was correlated invasion dendrites. Quantitative morphometric analyses revealed dichotomy backpropagation occurred presence subtle differences diameter primary dendrite branching pattern. addition, not dependent on a number electrophysiological parameters (input resistance, resting potential, voltage sensitivity spike amplitude). There was, however, striking correlation shape potential at soma its dendrite; larger, faster-rising, narrower exhibited more (300–410 soma). Simple compartmental models could be generated response manipulations distribution sodium potassium channels Backpropagation efficacy also influenced local alterations side branches, but these effects were highly sensitive model parameters. Based findings, hypothesize observed is conferred primarily distribution, density, modulatory state voltage-gated along somatodendritic axis.