TY - JOUR
T1 - The synaptic inputs and thalamic projections of two classes of layer 6 corticothalamic neurons in primary somatosensory cortex of the mouse
AU - Whilden, Courtney Michelle
AU - Chevée, Maxime
AU - An, Seong Yeol
AU - Brown, Solange Pezon
N1 - Funding Information:
The authors thank Su‐Jeong Kim, Alina Spiegel and Alan Wei for comments on the manuscript. We also thank the Stanford Neuroscience Gene Vector and Virus Core, the Janelia Viral Tools Facility, and the UNC Vector Core for viral vectors. This work was supported by the National Institutes of Health (RO1 NS085121; P30NS050274; RF1 MH121539) and the National Science Foundation (NSF 1656592). This work was also supported by the GT3 Core Facility of the Salk Institute with funding from NIH‐NCI CCSG: P30 014195, an NINDS R24 Core Grant and funding from NEI. Courtney Michelle Whilden was supported by a Johns Hopkins Provost's Undergraduate Research Award. Maxime Chevée was supported by a Boehringer Ingelheim Fonds Fellowship. Solange Pezon Brown was supported by a Klingenstein‐Simons Fellowship in the Neurosciences.
Funding Information:
The authors thank Su-Jeong Kim, Alina Spiegel and Alan Wei for comments on the manuscript. We also thank the Stanford Neuroscience Gene Vector and Virus Core, the Janelia Viral Tools Facility, and the UNC Vector Core for viral vectors. This work was supported by the National Institutes of Health (RO1 NS085121; P30NS050274; RF1 MH121539) and the National Science Foundation (NSF 1656592). This work was also supported by the GT3 Core Facility of the Salk Institute with funding from NIH-NCI CCSG: P30 014195, an NINDS R24 Core Grant and funding from NEI. Courtney Michelle Whilden was supported by a Johns Hopkins Provost's Undergraduate Research Award. Maxime Chev?e was supported by a Boehringer Ingelheim Fonds Fellowship. Solange Pezon Brown was supported by a Klingenstein-Simons Fellowship in the Neurosciences.
Funding Information:
Boehringer Ingelheim Fonds; Johns Hopkins Provost's Undergraduate Research Award; Klingenstein‐Simons Fellowship in the Neurosciences; National Cancer Institute, Grant/Award Number: P30 014195; National Institute of Mental Health, Grant/Award Number: RF1 MH121539; National Institute of Neurological Disorders and Stroke, Grant/Award Numbers: P30 NS050274, R01 NS085121; National Science Foundation, Grant/Award Number: 1656592 Funding information
Publisher Copyright:
© 2021 The Authors. The Journal of Comparative Neurology published by Wiley Periodicals LLC.
PY - 2021/12
Y1 - 2021/12
N2 - Although corticothalamic neurons (CThNs) represent the largest source of synaptic input to thalamic neurons, their role in regulating thalamocortical interactions remains incompletely understood. CThNs in sensory cortex have historically been divided into two types, those with cell bodies in Layer 6 (L6) that project back to primary sensory thalamic nuclei and those with cell bodies in Layer 5 (L5) that project to higher-order thalamic nuclei and subcortical structures. Recently, diversity among L6 CThNs has increasingly been appreciated. In the rodent somatosensory cortex, two major classes of L6 CThNs have been identified: one projecting to the ventral posterior medial nucleus (VPM-only L6 CThNs) and one projecting to both VPM and the posterior medial nucleus (VPM/POm L6 CThNs). Using rabies-based tracing methods in mice, we asked whether these L6 CThN populations integrate similar synaptic inputs. We found that both types of L6 CThNs received local input from somatosensory cortex and thalamic input from VPM and POm. However, VPM/POm L6 CThNs received significantly more input from a number of additional cortical areas, higher order thalamic nuclei, and subcortical structures. We also found that the two types of L6 CThNs target different functional regions within the thalamic reticular nucleus (TRN). Together, our results indicate that these two types of L6 CThNs represent distinct information streams in the somatosensory cortex and suggest that VPM-only L6 CThNs regulate, via their more restricted circuits, sensory responses related to a cortical column while VPM/POm L6 CThNs, which are integrated into more widespread POm-related circuits, relay contextual information.
AB - Although corticothalamic neurons (CThNs) represent the largest source of synaptic input to thalamic neurons, their role in regulating thalamocortical interactions remains incompletely understood. CThNs in sensory cortex have historically been divided into two types, those with cell bodies in Layer 6 (L6) that project back to primary sensory thalamic nuclei and those with cell bodies in Layer 5 (L5) that project to higher-order thalamic nuclei and subcortical structures. Recently, diversity among L6 CThNs has increasingly been appreciated. In the rodent somatosensory cortex, two major classes of L6 CThNs have been identified: one projecting to the ventral posterior medial nucleus (VPM-only L6 CThNs) and one projecting to both VPM and the posterior medial nucleus (VPM/POm L6 CThNs). Using rabies-based tracing methods in mice, we asked whether these L6 CThN populations integrate similar synaptic inputs. We found that both types of L6 CThNs received local input from somatosensory cortex and thalamic input from VPM and POm. However, VPM/POm L6 CThNs received significantly more input from a number of additional cortical areas, higher order thalamic nuclei, and subcortical structures. We also found that the two types of L6 CThNs target different functional regions within the thalamic reticular nucleus (TRN). Together, our results indicate that these two types of L6 CThNs represent distinct information streams in the somatosensory cortex and suggest that VPM-only L6 CThNs regulate, via their more restricted circuits, sensory responses related to a cortical column while VPM/POm L6 CThNs, which are integrated into more widespread POm-related circuits, relay contextual information.
KW - corticothalamic neurons
KW - layer 6
KW - rabies virus
KW - somatosensory cortex
KW - thalamic reticular nucleus
KW - trans-synaptic tracing
UR - http://www.scopus.com/inward/record.url?scp=85105186479&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85105186479&partnerID=8YFLogxK
U2 - 10.1002/cne.25163
DO - 10.1002/cne.25163
M3 - Article
C2 - 33908623
AN - SCOPUS:85105186479
SN - 0021-9967
VL - 529
SP - 3751
EP - 3771
JO - Journal of Comparative Neurology
JF - Journal of Comparative Neurology
IS - 17
ER -