Park, J., Papoutsi, A., Ash, R. T., Marin, M. A., Poirazi, P., & Smirnakis, S. M. (2019).
Contribution of apical and basal dendrites to orientation encoding in mouse V1 L2/3 pyramidal
neurons. Nature communications, 10(1), 1-11. https://www.nature.com/articles/s41467-019-13029-0
2-photon dendritic micro-dissection of dendritic branches, calcium imaging
Mouse V1 L2/3 pyramidal neurons
Uses 2-photon dendritic micro-dissection to precisely cut off dendritic branches and see the
effect (after 1-5 days) on the cell’s orientation tuning. Pre- and post-dissection tuning are determined via
calcium imaging of soma while mouse views moving gratings. Result: “Loss of apical input does not alter
orientation preference”, “Orientation tuning is robust to loss of multiple basal dendrites.” Authors create a
range of models whose apical and basal synapses sample from different orientation preference
distributions. They compare these models to their micro-dissection results. This comparison suggests that
each basal dendrite has an orientation tuning that is offset from the soma’s, implying that they learn
somewhat independently. Authors suggest this is evidence of local dendritic learning: “ Such
heterogeneity may arise from dendrite-specific forms of plasticity potentially mediated by spatially
restricted biochemical signaling and/or dendritic spikes.”
“[T]he remarkable robustness of orientation preference under dendritic micro-dissection
hints at the extraordinary ability of sensory cortical neurons to maintain functional selectivity
following input loss. Our approach emphasizes the importance of applying causal manipulations
to study the contribution of dendritic arbors to sensory encoding. Dendritic microdissection is a
powerful method for probing causal relations between dendritic structure/function and somatic
properties that can be applied to several key questions in systems neuroscience research.”