The role of higher order thalamus during learning and correct performance in goal-directed behavior
- University of Melbourne, Australia
- Trinity College Dublin, Ireland
Abstract
The thalamus is a gateway to the cortex. Cortical encoding of complex behavior can therefore only be understood by considering the thalamic processing of sensory and internally-generated information. Here, we use two-photon Ca2+ imaging and optogenetics to investigate the role of axonal projections from the posteromedial nucleus of the thalamus (POm) to the forepaw area of the mouse primary somatosensory cortex (forepaw S1). By recording the activity of POm axonal projections within forepaw S1 during expert and chance performance in two tactile goal-directed tasks, we demonstrate that POm axons increase activity in the response and, to a lesser extent, reward epochs specifically during correct HIT performance. When performing at chance level during learning of a new behavior, POm axonal activity was decreased to naïve rates and did not correlate with task performance. However, once evoked, the Ca2+ transients were larger than during expert performance, suggesting POm input to S1 differentially encodes chance and expert performance. Furthermore, the POm influences goal-directed behavior, as photo-inactivation of archaerhodopsin-expressing neurons in the POm decreased the learning rate and overall success in the behavioral task. Taken together, these findings expand the known roles of the higher-thalamic nuclei, illustrating the POm encodes and influences correct action during learning and performance in a sensory-based goal-directed behavior.
Data availability
The source code for the behavioral system can be found online at https://github.com/palmerlab/behaviour_box, as well as additional documentation at https://palmerlab.github.io. Calcium imaging data is available on Dryad doi:10.5061/dryad.1rn8pk0wb.
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Data from: The role of higher order thalamus during learning and correct performance in goal-directed behaviorDryad Digital Repository,doi:10.5061/dryad.1rn8pk0wb.
Article and author information
Author details
Funding
National Health and Medical Research Council (APP1086082)
- Lucy Maree Palmer
National Health and Medical Research Council (APP1063533)
- Lucy Maree Palmer
National Health and Medical Research Council (APP1085708)
- Lucy Maree Palmer
Australian Respiratory Council (DP160103047)
- Lucy Maree Palmer
Sylvia and Charles Viertel Charitable Foundation
- Lucy Maree Palmer
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 procedures were approved by the Florey Institute of Neuroscience and Mental Health Animal Care and Ethics Committee and followed the guidelines of the Australian Code of Practice for the Care and Use of Animals for Scientific Purpose
Copyright
© 2022, La Terra 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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