PT  - JOURNAL ARTICLE
AU  - Valerio Francioni
AU  - Nathalie L. Rochefort
TI  - High and asymmetric somato-dendritic coupling of V1 layer 5 neurons independent of behavioural state and visual stimulation
AID  - 10.1101/664177
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 664177
4099  - http://biorxiv.org/content/early/2019/07/02/664177.short
4100  - http://biorxiv.org/content/early/2019/07/02/664177.full
AB  - Active dendritic conductances impact the integration of synaptic inputs. However, the extent to which dendrites act as independent computational subunits in vivo, remains unclear. We imaged semi-simultaneously calcium signals in the soma, trunk and distal tuft dendrites of individual layer 5 pyramidal neurons in the awake primary visual cortex. We found highly correlated calcium transients throughout the whole apical tuft: branch-specific activity was rare and limited to the smallest calcium transients. While apical tuft calcium transients were highly correlated to trunk and somatic transients, the frequency of calcium transients was found to decrease in a distance- and amplitude-dependent manner from soma to apical tuft. Visual stimulation and locomotion increased global apical tuft activity but did not alter the coupling between soma and apical tuft. These results suggest that the apical tuft acts as a single computational unit and that its coupling to somatic signals is strong and asymmetric.