RT Journal Article
SR Electronic
T1 Dendritic integration of sensory and reward information facilitates learning
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.12.28.474360
DO 10.1101/2021.12.28.474360
A1 Gwendolin Schoenfeld
A1 Sepp Kollmorgen
A1 Christopher Lewis
A1 Philipp Bethge
A1 Anna Maria Reuss
A1 Adriano Aguzzi
A1 Valerio Mante
A1 Fritjof Helmchen
YR 2021
UL http://biorxiv.org/content/early/2021/12/28/2021.12.28.474360.abstract
AB Learning goal-directed behaviours requires integration of separate information streams representing context, relevant stimuli and reward. Dendrites of pyramidal neurons are suitable sites for such integration, but it remains elusive how their responses adapt when an animal learns a new task. Here, we identify two distinct classes of dendritic responses that represent either contextual/sensory information or reward information and that differ in their task- and learning-related dynamics. Using longitudinal calcium imaging of apical dendritic tufts of L5 pyramidal neurons in mouse barrel cortex, we tracked dendritic activity across learning and analyzed both local dendritic branch signals and global apical tuft activity. During texture discrimination learning, sensory representations (including contextual and touch information) strengthened and converged on the reward-predicting tactile stimulus when mice became experts. In contrast, reward-associated responses were particularly strong in the naïve condition and became less pronounced upon learning. When we blocked the representation of unexpected reward in naïve animals with optogenetic inhibition, animals failed to learn until we released the block and learning proceeded normally. Our results suggest that reward signals in dendrites are essential for adjusting neuronal integration of converging inputs to facilitate adaptive behaviour.Competing Interest StatementThe authors have declared no competing interest.