CONTEXTUAL ENCODING IN VIBRISSAL SENSORIMOTOR CORTICAL AND THALAMIC CIRCUITS

How cortical and thalamic circuits flexibly transform sensory and contextual information into behavior remains incompletely understood. In particular, it is unclear how overlapping neural signals such as activation of the primary somatosensory cortex (S1bf) are interpreted differently to drive distinct actions across behavioral contexts. To address this mice (n = 8) were trained in two whisker-based sensorimotor tasks. In one task, mice actively moved a whisker to touch an object within a 2s response window; in the other, they responded to an air puff delivered to a whisker by licking. These tasks were rewarded from separate reward tubes. During task performance, orofacial and postural behaviors were tracked while neural activity was recorded from S1bf, primary motor cortex (M1), and posteromedial thalamus (VPM/PoM) using Neuropixels probes. In a subset of trials on recording days, S1bf was electrically stimulated with a platinum-iridium microprobe. Preliminary results indicate that individual neurons in posteromedial thalamus were active across multiple contexts, consistent with multiplexed encoding, whereas M1 neurons exhibited strong context dependence, responding differentially during whisker movement, active touch, air-puff stimulation, or direct cortical activation. Ongoing analyses are examining whether activity in S1bf, M1, or thalamus predicts orofacial behavior, whether direct activation of S1bf preferentially evokes whisking or directional licking, and whether activity in S1bf and thalamus predicts the patterns of context-dependent activity observed in M1.