STATE-RELATED NEURAL DYNAMICS IN THE VISUAL THALAMUS OF FREELY MOVING MICE

To adequately interact with their environment, animals must integrate visual signals from their surroundings together with internal signals from their body. How and where this integration occurs remains unclear, but accumulating evidence indicates that the visual thalamus plays an important role in this process.
Most studies addressing this role have been conducted in subjects whose body movements are highly restricted and who are presented with artificial stimuli on a computer. However, various types of physiological and bodily states cannot be studied under such conditions, which greatly limits the current progress in deciphering the role of the thalamus in shaping ‘real world’ sensory behaviour.
To overcome these limitations, we have performed high-density neural recordings in the primary visual thalamus (dLGN) of freely moving mice while monitoring changes in their physiological and bodily state via videography. Preliminary results from our experiments support previous findings that dLGN neurons strongly encode arousal- and motor movement-related signals. Furthermore, we demonstrate that these signals explain a significant proportion of the neural variance of the average dLGN population activity. Additionally, we identified different clusters of dLGN neurons that differentially encode positional signals of body parts.
Overall, our results lend strong support to the hypothesis that the visual thalamus encodes a diverse array of state-related signals and integrates those together with sensory information to guide behavior.