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bioRxiv · 10.1101/2023.06.02.543490

Dendritic voltage imaging reveals biophysical basis of associative plasticity rules

Park, P.·Wong-Campos, J. D.·Itkis, D.·Qi, Y.·Davis, H. C.·Grimm, J. B.·Plutkis, S. E.·Lavis, L.·Cohen, A. E.
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Abstract

Dendrites on neurons support nonlinear electrical excitations, but the computational significance of these events is not well understood. We developed molecular, optical, and analytical tools to map sub-millisecond voltage dynamics throughout the dendritic trees of CA1 pyramidal neurons under diverse optogenetic and synaptic stimulus patterns, in acute brain slices. We observed history-dependent spike back-propagation in distal dendrites, driven by locally generated Na+ spikes (dSpikes). Dendritic depolarization created a transient window for dSpike propagation, opened by A-type KV channel inactivation, and closed by slow NaV inactivation. Collisions of dSpikes with synaptic inputs triggered calcium channel and N-methyl-D-aspartate receptor (NMDAR)-dependent plateau potentials, with accompanying complex spikes at the soma. This hierarchical ion channel network acts as a spike-rate accelerometer, providing an intuitive picture of how dendritic excitations shape associative plasticity rules.

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Park, P., Wong-Campos, J. D., Itkis, D., Qi, Y., Davis, H. C., Grimm, J. B., Plutkis, S. E., Lavis, L., Cohen, A. E.. 2023-06-02. Dendritic voltage imaging reveals biophysical basis of associative plasticity rules. https://doi.org/10.1101/2023.06.02.543490

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