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bioRxiv · 10.64898/2026.01.18.700189

A dendrite-resolved, in vivo transfer function from spike patterns to dendritic Ca2+

Wu, X.·Lee, B. H.·Park, P.·Wong-Campos, J. D.·Xu, J.·Plutkis, S. E.·Lavis, L. D.·Cohen, A. E.
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Abstract

Dendrites transform local electrical activity into intracellular Ca2+ signals that drive plasticity1,2, yet the voltage[->]Ca2+ mapping during natural behavior remains poorly defined. Here, we measure this transfer function via simultaneous voltage and Ca2+ imaging throughout the dendritic arbors of hippocampal CA2 pyramidal neurons in behaving mice. Dendritic Ca2+ exhibited a hierarchical activation pattern dominated by back-propagating action potentials: simple spikes primarily drove somatic and proximal Ca2+, whereas complex spikes produced larger somatic Ca2+ signals and propagated farther into distal dendrites, sometimes in a branch-selective manner. Dendrite-restricted co-activation of voltage and Ca2+ without concurrent somatic events was rare. A biophysics-inspired model accurately predicted local Ca2+ transients from local voltage waveforms. Our data and model provide a quantitative understanding of when - and why - dendritic Ca2+ signals in CA2 pyramidal cells arise during behavior.

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Wu, X., Lee, B. H., Park, P., Wong-Campos, J. D., Xu, J., Plutkis, S. E., Lavis, L. D., Cohen, A. E.. 2026-01-21. A dendrite-resolved, in vivo transfer function from spike patterns to dendritic Ca2+. https://doi.org/10.64898/2026.01.18.700189

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