Convergence of inputs from the basal ganglia with layer 5 of motor cortex and cerebellum in mouse motor thalamus
- University of Chicago, United States
Abstract
A key to motor control is the motor thalamus, where several inputs converge. One excitatory input originates from layer 5 of primary motor cortex (M1L5), while another arises from the deep cerebellar nuclei (Cb). M1L5 terminals distribute throughout the motor thalamus and overlap with GABAergic inputs from the basal ganglia output nuclei, the internal segment of the globus pallidus (GPi) and substantia nigra pars reticulata (SNr). In contrast, it is thought that Cb and basal ganglia inputs are segregated. Therefore, we hypothesized that one potential function of the GABAergic inputs from basal ganglia is to selectively inhibit, or gate, excitatory signals from M1L5 in the motor thalamus. Here, we tested this possibility and determined the circuit organization of mouse (both sexes) motor thalamus using an optogenetic strategy in acute slices. First, we demonstrated the presence of a feedforward transthalamic pathway from M1L5 through motor thalamus. Importantly, we discovered that GABAergic inputs from the GPi and SNr converge onto single motor thalamic cells with excitatory synapses from M1L5. Separately, we also demonstrate that, perhaps unexpectedly, GABAergic GPi and SNr inputs converge with those from the Cb. We interpret these results to indicate that a role of the basal ganglia is to gate the thalamic transmission of M1L5 and Cb information to cortex.
Data availability
All data generated or analyzed during this study are represented in the Figures. Mean values and sample variability are listed in the Results section of the text where applicable. Individual data points are represented on the graphs/Figures. In addition, source data files for all quantitate data are provided.
Article and author information
Author details
Funding
National Institute of Neurological Disorders and Stroke (NS094184)
- S Murray Sherman
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Eunji Cheong, Yonsei University, Republic of Korea
Ethics
Animal experimentation: All experiments were performed in accordance with protocols approved by the Institutional Animal Care and Use Committee at the University of Chicago.
Version history
- Received: March 1, 2024
- Preprint posted: March 14, 2024 (view preprint)
- Accepted: June 6, 2024
- Accepted Manuscript published: June 10, 2024 (version 1)
- Version of Record published: June 26, 2024 (version 2)
Copyright
© 2024, Koster & Sherman
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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Convergence of inputs from the basal ganglia with layer 5 of motor cortex and cerebellum in mouse motor thalamus
eLife 13:e97489.
https://doi.org/10.7554/eLife.97489
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