The active properties of dendrites can support local nonlinear operations, but previous imaging and electrophysiological measurements have produced conflicting views regarding the prevalence and selectivity of local nonlinearities in vivo. We imaged calcium signals in pyramidal cell dendrites in the motor cortex of mice performing a tactile decision task. A custom microscope allowed us to image the soma and up to 300 μm of contiguous dendrite at 15 Hz, while resolving individual spines. New analysis methods were used to estimate the frequency and spatial scales of activity in dendritic branches and spines. The majority of dendritic calcium transients were coincident with global events. However, task-associated calcium signals in dendrites and spines were compartmentalized by dendritic branching and clustered within branches over approximately 10 μm. Diverse behavior-related signals were intermingled and distributed throughout the dendritic arbor, potentially supporting a large learning capacity in individual neurons.
Bibliographical noteFunding Information:
We would like to thank Na Ji and Rongwen Lu for advice and assistance on microscopy; Charles Ger-fen for the Syt17-NO14-Cre and Chrna2-OE25-Cre mice; Mark Johnson, Tara Srirangarajan, and Rinat Mohar for mouse training and surgery; Jeremy Freeman and Jason Wittenbach for help with parallel computing; Jinyao Yan and Srini Turaga for useful discussions; Jeffrey Magee, Kaspar Podg-orski, and Hod Dana for comments on the manuscript. This work was funded by Howard Hughes Medical Institute.
© Kerlin et al.