1
|
Martinetti LE, Autio DM, Crandall SR. Motor Control of Distinct Layer 6 Corticothalamic Feedback Circuits. eNeuro 2024; 11:ENEURO.0255-24.2024. [PMID: 38926084 PMCID: PMC11236587 DOI: 10.1523/eneuro.0255-24.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Accepted: 06/20/2024] [Indexed: 06/28/2024] Open
Abstract
Layer 6 corticothalamic (L6 CT) neurons provide massive input to the thalamus, and these feedback connections enable the cortex to influence its own sensory input by modulating thalamic excitability. However, the functional role(s) feedback serves during sensory processing is unclear. One hypothesis is that CT feedback is under the control of extrasensory signals originating from higher-order cortical areas, yet we know nothing about the mechanisms of such control. It is also unclear whether such regulation is specific to CT neurons with distinct thalamic connectivity. Using mice (either sex) combined with in vitro electrophysiology techniques, optogenetics, and retrograde labeling, we describe studies of vibrissal primary motor cortex (vM1) influences on different CT neurons in the vibrissal primary somatosensory cortex (vS1) with distinct intrathalamic axonal projections. We found that vM1 inputs are highly selective, evoking stronger postsynaptic responses in CT neurons projecting to the dual ventral posterior medial nucleus (VPm) and posterior medial nucleus (POm) located in lower L6a than VPm-only-projecting CT cells in upper L6a. A targeted analysis of the specific cells and synapses involved revealed that the greater responsiveness of Dual CT neurons was due to their distinctive intrinsic membrane properties and synaptic mechanisms. These data demonstrate that vS1 has at least two discrete L6 CT subcircuits distinguished by their thalamic projection patterns, intrinsic physiology, and functional connectivity with vM1. Our results also provide insights into how a distinct CT subcircuit may serve specialized roles specific to contextual modulation of tactile-related sensory signals in the somatosensory thalamus during active vibrissa movements.
Collapse
Affiliation(s)
- Luis E Martinetti
- Neuroscience Program, Michigan State University, East Lansing, Michigan 48824
| | - Dawn M Autio
- Department of Physiology, Michigan State University, East Lansing, Michigan 48824
| | - Shane R Crandall
- Neuroscience Program, Michigan State University, East Lansing, Michigan 48824
- Department of Physiology, Michigan State University, East Lansing, Michigan 48824
| |
Collapse
|
2
|
Martinetti LE, Autio DM, Crandall SR. Motor Control of Distinct Layer 6 Corticothalamic Feedback Circuits. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.22.590613. [PMID: 38712153 PMCID: PMC11071411 DOI: 10.1101/2024.04.22.590613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Layer 6 corticothalamic (L6 CT) neurons provide massive input to the thalamus, and these feedback connections enable the cortex to influence its own sensory input by modulating thalamic excitability. However, the functional role(s) feedback serves during sensory processing is unclear. One hypothesis is that CT feedback is under the control of extra-sensory signals originating from higher-order cortical areas, yet we know nothing about the mechanisms of such control. It is also unclear whether such regulation is specific to CT neurons with distinct thalamic connectivity. Using mice (either sex) combined with in vitro electrophysiology techniques, optogenetics, and retrograde labeling, we describe studies of vibrissal primary motor cortex (vM1) influences on different CT neurons in the vibrissal primary somatosensory cortex (vS1) with distinct intrathalamic axonal projections. We found that vM1 inputs are highly selective, evoking stronger postsynaptic responses in Dual ventral posterior medial nucleus (VPm) and posterior medial nucleus (POm) projecting CT neurons located in lower L6a than VPm-only projecting CT cells in upper L6a. A targeted analysis of the specific cells and synapses involved revealed that the greater responsiveness of Dual CT neurons was due to their distinctive intrinsic membrane properties and synaptic mechanisms. These data demonstrate that vS1 has at least two discrete L6 CT subcircuits distinguished by their thalamic projection patterns, intrinsic physiology, and functional connectivity with vM1. Our results also provide insights into how a distinct CT subcircuit may serve specialized roles specific to contextual modulation of tactile-related sensory signals in the somatosensory thalamus during active vibrissa movements.
Collapse
Affiliation(s)
| | - Dawn M. Autio
- Department of Physiology, Michigan State University, East Lansing, MI 48824
| | - Shane R. Crandall
- Neuroscience Program, Michigan State University, East Lansing, MI 48824
- Department of Physiology, Michigan State University, East Lansing, MI 48824
| |
Collapse
|
3
|
Dimwamwa ED, Pala A, Chundru V, Wright NC, Stanley GB. Dynamic corticothalamic modulation of the somatosensory thalamocortical circuit during wakefulness. Nat Commun 2024; 15:3529. [PMID: 38664415 PMCID: PMC11045850 DOI: 10.1038/s41467-024-47863-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 04/10/2024] [Indexed: 04/28/2024] Open
Abstract
The feedback projections from cortical layer 6 (L6CT) to the sensory thalamus have long been implicated in playing a primary role in gating sensory signaling but remain poorly understood. To causally elucidate the full range of effects of these projections, we targeted silicon probe recordings to the whisker thalamocortical circuit of awake mice selectively expressing Channelrhodopsin-2 in L6CT neurons. Through optogenetic manipulation of L6CT neurons, multi-site electrophysiological recordings, and modeling of L6CT circuitry, we establish L6CT neurons as dynamic modulators of ongoing spiking in the ventral posteromedial nucleus of the thalamus (VPm), either suppressing or enhancing VPm spiking depending on L6CT neurons' firing rate and synchrony. Differential effects across the cortical excitatory and inhibitory sub-populations point to an overall influence of L6CT feedback on cortical excitability that could have profound implications for regulating sensory signaling across a range of ethologically relevant conditions.
Collapse
Affiliation(s)
- Elaida D Dimwamwa
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Aurélie Pala
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
- Department of Biology, Emory University, Atlanta, GA, USA
| | - Vivek Chundru
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Nathaniel C Wright
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Garrett B Stanley
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
| |
Collapse
|
4
|
Dimwamwa E, Pala A, Chundru V, Wright NC, Stanley GB. Dynamic corticothalamic modulation of the somatosensory thalamocortical circuit during wakefulness. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.07.18.549491. [PMID: 37503253 PMCID: PMC10370106 DOI: 10.1101/2023.07.18.549491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
The feedback projections from cortical layer 6 (L6CT) to sensory thalamus have long been implicated in playing a primary role in gating sensory signaling but remain poorly understood. To causally elucidate the full range of effects of these projections, we targeted silicon probe recordings to the whisker thalamocortical circuit of awake mice selectively expressing Channelrhodopsin-2 in L6CT neurons. Through optogenetic manipulation of L6CT neurons, multi-site electrophysiological recordings, and modeling of L6CT circuitry, we establish L6CT neurons as dynamic modulators of ongoing spiking in the ventro-posterior-medial nucleus of thalamus (VPm), either suppressing or enhancing VPm spiking depending on L6CT neurons' firing rate and synchrony. Differential effects across the cortical excitatory and inhibitory sub-populations point to an overall influence of L6CT feedback on cortical excitability that could have profound implications for regulating sensory signaling across a range of ethologically relevant conditions.
Collapse
|
5
|
Kawatani M, Horio K, Ohkuma M, Li WR, Yamashita T. Interareal Synaptic Inputs Underlying Whisking-Related Activity in the Primary Somatosensory Barrel Cortex. J Neurosci 2024; 44:e1148232023. [PMID: 38050130 PMCID: PMC10860602 DOI: 10.1523/jneurosci.1148-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 11/22/2023] [Accepted: 11/24/2023] [Indexed: 12/06/2023] Open
Abstract
Body movements influence brain-wide neuronal activities. In the sensory cortex, thalamocortical bottom-up inputs and motor-sensory top-down inputs are thought to affect the dynamics of membrane potentials (Vm ) of neurons and change their processing of sensory information during movements. However, direct perturbation of the axons projecting to the sensory cortex from other remote areas during movements has remained unassessed, and therefore the interareal circuits generating motor-related signals in sensory cortices remain unclear. Using a Gi/o -coupled opsin, eOPN3, we here inhibited interareal signals incoming to the whisker primary somatosensory barrel cortex (wS1) of awake male mice and tested their effects on whisking-related changes in neuronal activities in wS1. Spontaneous whisking in air induced the changes in spike rates of a subset of wS1 neurons, which were accompanied by depolarization and substantial reduction of slow-wave oscillatory fluctuations of Vm Despite an extensive innervation, inhibition of inputs from the whisker primary motor cortex (wM1) to wS1 did not alter the spike rates and Vm dynamics of wS1 neurons during whisking. In contrast, inhibition of axons from the whisker-related thalamus (wTLM) and the whisker secondary somatosensory cortex (wS2) to wS1 largely attenuated the whisking-related supra- and sub-threshold Vm dynamics of wS1 neurons. Notably, silencing inputs from wTLM markedly decreased the modulation depth of whisking phase-tuned neurons in wS1, while inhibiting wS2 inputs did not impact the whisking variable tuning of wS1 neurons. Thus, sensorimotor integration in wS1 during spontaneous whisking is predominantly facilitated by direct synaptic inputs from wTLM and wS2 rather than from wM1.
Collapse
Affiliation(s)
- Masahiro Kawatani
- Department of Physiology, Fujita Health University School of Medicine, Toyoake, 470-1192, Japan
- Department of Functional Anatomy and Neuroscience, Graduate School of Medicine, Nagoya University, Nagoya, 466-8550, Japan
| | - Kayo Horio
- Department of Physiology, Fujita Health University School of Medicine, Toyoake, 470-1192, Japan
| | - Mahito Ohkuma
- Department of Physiology, Fujita Health University School of Medicine, Toyoake, 470-1192, Japan
| | - Wan-Ru Li
- Department of Physiology, Fujita Health University School of Medicine, Toyoake, 470-1192, Japan
- Department of Functional Anatomy and Neuroscience, Graduate School of Medicine, Nagoya University, Nagoya, 466-8550, Japan
| | - Takayuki Yamashita
- Department of Physiology, Fujita Health University School of Medicine, Toyoake, 470-1192, Japan
- International Center for Brain Science (ICBS), Fujita Health University, Toyoake, 470-1192, Japan
| |
Collapse
|
6
|
Soplata AE, Adam E, Brown EN, Purdon PL, McCarthy MM, Kopell N. Rapid thalamocortical network switching mediated by cortical synchronization underlies propofol-induced EEG signatures: a biophysical model. J Neurophysiol 2023; 130:86-103. [PMID: 37314079 PMCID: PMC10312318 DOI: 10.1152/jn.00068.2022] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 06/08/2023] [Accepted: 06/08/2023] [Indexed: 06/15/2023] Open
Abstract
Propofol-mediated unconsciousness elicits strong alpha/low-beta and slow oscillations in the electroencephalogram (EEG) of patients. As anesthetic dose increases, the EEG signal changes in ways that give clues to the level of unconsciousness; the network mechanisms of these changes are only partially understood. Here, we construct a biophysical thalamocortical network involving brain stem influences that reproduces transitions in dynamics seen in the EEG involving the evolution of the power and frequency of alpha/low-beta and slow rhythm, as well as their interactions. Our model suggests that propofol engages thalamic spindle and cortical sleep mechanisms to elicit persistent alpha/low-beta and slow rhythms, respectively. The thalamocortical network fluctuates between two mutually exclusive states on the timescale of seconds. One state is characterized by continuous alpha/low-beta-frequency spiking in thalamus (C-state), whereas in the other, thalamic alpha spiking is interrupted by periods of co-occurring thalamic and cortical silence (I-state). In the I-state, alpha colocalizes to the peak of the slow oscillation; in the C-state, there is a variable relationship between an alpha/beta rhythm and the slow oscillation. The C-state predominates near loss of consciousness; with increasing dose, the proportion of time spent in the I-state increases, recapitulating EEG phenomenology. Cortical synchrony drives the switch to the I-state by changing the nature of the thalamocortical feedback. Brain stem influence on the strength of thalamocortical feedback mediates the amount of cortical synchrony. Our model implicates loss of low-beta, cortical synchrony, and coordinated thalamocortical silent periods as contributing to the unconscious state.NEW & NOTEWORTHY GABAergic anesthetics induce alpha/low-beta and slow oscillations in the EEG, which interact in dose-dependent ways. We constructed a thalamocortical model to investigate how these interdependent oscillations change with propofol dose. We find two dynamic states of thalamocortical coordination, which change on the timescale of seconds and dose-dependently mirror known changes in EEG. Thalamocortical feedback determines the oscillatory coupling and power seen in each state, and this is primarily driven by cortical synchrony and brain stem neuromodulation.
Collapse
Affiliation(s)
- Austin E Soplata
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
- Department of Mathematics and Statistics, Boston University, Boston, Massachusetts, United States
| | - Elie Adam
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
| | - Emery N Brown
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
| | - Patrick L Purdon
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Michelle M McCarthy
- Department of Mathematics and Statistics, Boston University, Boston, Massachusetts, United States
| | - Nancy Kopell
- Department of Mathematics and Statistics, Boston University, Boston, Massachusetts, United States
| |
Collapse
|
7
|
Ziegler K, Folkard R, Gonzalez AJ, Burghardt J, Antharvedi-Goda S, Martin-Cortecero J, Isaías-Camacho E, Kaushalya S, Tan LL, Kuner T, Acuna C, Kuner R, Mease RA, Groh A. Primary somatosensory cortex bidirectionally modulates sensory gain and nociceptive behavior in a layer-specific manner. Nat Commun 2023; 14:2999. [PMID: 37225702 DOI: 10.1038/s41467-023-38798-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 05/16/2023] [Indexed: 05/26/2023] Open
Abstract
The primary somatosensory cortex (S1) is a hub for body sensation of both innocuous and noxious signals, yet its role in somatosensation versus pain is debated. Despite known contributions of S1 to sensory gain modulation, its causal involvement in subjective sensory experiences remains elusive. Here, in mouse S1, we reveal the involvement of cortical output neurons in layers 5 (L5) and 6 (L6) in the perception of innocuous and noxious somatosensory signals. We find that L6 activation can drive aversive hypersensitivity and spontaneous nocifensive behavior. Linking behavior to neuronal mechanisms, we find that L6 enhances thalamic somatosensory responses, and in parallel, strongly suppresses L5 neurons. Directly suppressing L5 reproduced the pronociceptive phenotype induced by L6 activation, suggesting an anti-nociceptive function for L5 output. Indeed, L5 activation reduced sensory sensitivity and reversed inflammatory allodynia. Together, these findings reveal a layer-specific and bidirectional role for S1 in modulating subjective sensory experiences.
Collapse
Affiliation(s)
- Katharina Ziegler
- Medical Biophysics, Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Ross Folkard
- Medical Biophysics, Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Antonio J Gonzalez
- Medical Biophysics, Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Jan Burghardt
- Medical Biophysics, Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Sailaja Antharvedi-Goda
- Medical Biophysics, Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Jesus Martin-Cortecero
- Medical Biophysics, Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Emilio Isaías-Camacho
- Medical Biophysics, Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Sanjeev Kaushalya
- Department of Molecular Pharmacology, Institute for Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Linette Liqi Tan
- Department of Molecular Pharmacology, Institute for Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Thomas Kuner
- Institute for Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany
| | - Claudio Acuna
- Chica and Heinz Schaller Research Group, Institute for Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany
| | - Rohini Kuner
- Department of Molecular Pharmacology, Institute for Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Rebecca Audrey Mease
- Medical Biophysics, Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany.
| | - Alexander Groh
- Medical Biophysics, Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany.
| |
Collapse
|