Tuning Heterogeneity in Barrel Cortex Improves Sensory Acuity in Behaving Mice

Abstract

Though the cortical column is well-studied, the function of cells tuned to adjacent sensors (heterogeneous cells) is unknown, especially regarding sensory spatial acuity in behaving animals. We increased tuning heterogeneity in mice vibrissal primary somatosensory cortex (vS1) by environmental enrichment. Single-neuron activity in vS1 and vibrissal premotor cortex (vM2) was recorded using two-photon calcium imaging while mice performed a two-adjacent-whisker discrimination task. Enriched animals performed better at spatial discrimination, despite increased whisker tuning heterogeneity. Heterogeneous vS1 cells and vM2 cells are strong neural correlates of behavior. Single-column inhibition decreased the animal’s spatial acuity and vM2 cells’ ability to encode the animal’s decision. Our results suggest that the functional overlap between columns in vS1 does not translate to obscured spatial acuity in sensory percept. Rather, heterogeneous vS1 cells play an important role in the animal’s perceptual decision and the neural processes in the frontal cortex underlying such decisions.

Keywords: Tuning heterogeneity, two-whisker discrimination task, enriched environment, single-column inhibition, decision making, vibrissal premotor cortex