READING THE NEURAL CODE

In reading out the neural code, our laboratory has focused on signal processing and computational strategies used by the brain in sensory signaling. We have a large body of work devoted to coding by neuronal populations in the thalamocortical circuit

Adaptative coding. One major challenge in understanding how the brain encodes information is that the signal processing is adaptive – that is that it changes as the sensory world changes (Whitmire & Stanley, 2016). In past work, we have published extensively on this topic in the visual and somatosensory pathways.  Most recently, we have explored this in the context of thalamocortical signaling during wakefulness in the somatosensory pathway, finding that rapid sensory adaptation in the cortex largely reflects adaptive changes in synchronous thalamic firing combined with the robust engagement of feedforward inhibition (Wright et al., 2021). In parallel behavioral studies, we have explored adaptation at different time scales, during the course of learning in sensory-driven behaviors. We recently showed that animals adapt their behavior to maintain reward expectations when challenged with a changing tactile landscape (Waiblinger et al., 2019), and that the primary sensory cortex plays an increasingly critical role in this kind of adaptive behavior while gaining expertise (Waiblinger et al., 2022).

Thalamic gating.  The thalamus is a deep brain structure that plays a pivotal role in connecting peripheral sensors to cortical circuits that are thought to underlie perception, cognition, decision-making, etc.  We have previously shown that changes in thalamic synchrony trade-off between signaling processing regimes that favor either detection or discrimination (Wang et al., 2010), and that this is reflected in trained behavior (Ollerenshaw et al., 2014).  In recent work, we used an array of experimental and computational approaches to determine the role of thalamic bursting in gating sensory signaling during wakefulness (Borden et al., 2022), showing that the cortical representation of sensory signaling is strongly gated by burst/tonic mediated changes in precise thalamic timing/synchrony.   In an ongoing study, we are further exploring the role of corticothalamic feedback in gating sensory signaling using a transgenic mouse line that enables us to precisely target the feedback pathway (Dimwamwa et al., 2022).