Tuft dendrites in frontal motor cortex enable flexible learning
Summary
Flexible learning relies on integrating sensory and contextual information to adjust behavioral output in different environments. The anterolateral motor cortex (ALM) is a frontal area critical for action selection in rodents. We found that inputs critical to decision-making converge on the apical tuft dendrites of layer 5b pyramidal neurons in ALM. We therefore investigated the role of these dendrites in a rule-switching paradigm. Activation of dendrite-inhibiting layer 1 interneurons imp
Content
# Tuft dendrites in frontal motor cortex enable flexible learning
*Published: 2026 May 7*
Flexible learning relies on integrating sensory and contextual information to
adjust behavioral output in different environments. The anterolateral motor
cortex (ALM) is a frontal area critical for action selection in rodents. We
found that inputs critical to decision-making converge on the apical tuft
dendrites of layer 5b pyramidal neurons in ALM. We therefore investigated the
role of these dendrites in a rule-switching paradigm. Activation of
dendrite-inhibiting layer 1 interneurons impaired relearning, without affecting
previously learned behavior. This inhibition profoundly suppressed global
calcium activity in dendritic shafts but not local transients in spines, while
additionally reducing burst firing. Moreover, excitatory synaptic inputs to tuft
dendrites exhibited rule-dependent clustering. We conclude that dendritic
calcium signaling is a key computational component of flexible learning.
DOI: 10.1126/science.adx4358