Effects of arousal and movement on secondary somatosensory and visual thalamus
Abstract
Neocortical sensory areas have associated primary and secondary thalamic nuclei. While primary nuclei transmit sensory information to cortex, secondary nuclei remain poorly understood. We recorded juxtasomally from secondary somatosensory (POm) and visual (LP) nuclei of awake mice while tracking whisking and pupil size. POm activity correlated with whisking, but not precise whisker kinematics. This coarse movement modulation persisted after facial paralysis and thus was not due to sensory reafference. This phenomenon also continued during optogenetic silencing of somatosensory and motor cortex and after lesion of superior colliculus, ruling out a motor efference copy mechanism. Whisking and pupil dilation were strongly correlated, possibly reflecting arousal. Indeed LP, which is not part of the whisker system, tracked whisking equally well, further indicating that POm activity does not encode whisker movement per se. The semblance of movement-related activity is likely instead a global effect of arousal on both nuclei. We conclude that secondary thalamus monitors behavioral state, rather than movement, and may exist to alter cortical activity accordingly.
Data availability
Data have been deposited in Dryad.
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Data from: Effects of arousal and movement on secondary somatosensory and visual thalamusDryad Digital Repository, doi:10.5061/dryad.280gb5mr4.
Article and author information
Author details
Funding
National Institute of Neurological Disorders and Stroke (R01 NS094659)
- Randy M Bruno
National Institute of Neurological Disorders and Stroke (R01 NS069679)
- Randy M Bruno
National Eye Institute (T32 EY013933)
- Gordon H Petty
- Amanda K Kinnischtzke
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: All experiments complied with the NIH Guide for the Care and Use of Laboratory Animals and were approved by the Institutional Animal Care and Use Committee of Columbia University (protocol AC-AAAY8462).
Copyright
© 2021, Petty et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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