Cortical circuits for whisker sensory perception-From barrel columns to brain-wide interactions.

The sense of touch provides spatial and textural information but how tactile input is integrated with motor signals and selectively processed for adaptive behavior remain incompletely understood. Here, I review neuronal circuits contributing to whisker sensation in rodents at three different levels. First, I point to the columnar architecture of the primary somatosensory cortex in which whiskers are individually represented by barrel columns with intricate microcircuits, likely important for processing tactile information from individual whiskers. Next, I highlight the importance of lateral interactions within the barrel cortex, which likely underlie shape perception as multiple whiskers sample an object surface. Finally, I consider the growing body of research implicating brain-wide interactions to support adaptive behavior, specifically focusing on roles of long-range projection neurons from the barrel cortex to a large number of downstream brain regions. Such brain-wide communication poses important challenges for experimental, computational and theoretical neuroscience necessitating new technical and conceptual advances.