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Sugawara SK, Nishimura Y. The Mesocortical System Encodes the Strength of Subsequent Force Generation. Neurosci Insights 2024; 19:26331055241256948. [PMID: 38827248 PMCID: PMC11141215 DOI: 10.1177/26331055241256948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Accepted: 05/08/2024] [Indexed: 06/04/2024] Open
Abstract
Our minds impact motor outputs. Such mind-motor interactions are critical for understanding motor control mechanisms and optimizing motor performance. In particular, incentive motivation strongly enhances motor performance. Dopaminergic neurons located in the ventral midbrain (VM) are believed to be the center of incentive motivation. Direct projections from the VM to the primary motor cortex constitute a mesocortical pathway. However, the functional role of this pathway in humans remains unclear. Recently, we demonstrated the functional role of the mesocortical pathway in human motor control in the context of incentive motivation by using functional magnetic resonance imaging (fMRI). Incentive motivation remarkably improved not only reaction times but also the peak grip force in subsequent grip responses. Although the reaction time has been used as a proxy for incentive motivation mediated by dopaminergic midbrain activity, the premovement activity of the mesocortical pathway is involved in controlling the force strength rather than the initiation of subsequent force generation. In this commentary, we review our recent findings and discuss remaining questions regarding the functional role of the mesocortical pathway in mind-motor interactions.
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Affiliation(s)
- Sho K Sugawara
- Neural Prosthetics Project, Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo, Japan
| | - Yukio Nishimura
- Neural Prosthetics Project, Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo, Japan
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Boschen SL, Seethaler J, Wang S, Lujan WD, Silvernail JL, Carter RE, Chang SY, Lujan JL. Midbrain dopaminergic degeneration differentially modulates primary motor cortex activity and motor behavior in hemi-parkinsonian rats. RESEARCH SQUARE 2024:rs.3.rs-4365911. [PMID: 38798359 PMCID: PMC11118689 DOI: 10.21203/rs.3.rs-4365911/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Parkinson's disease (PD) is marked by degeneration in the nigrostriatal dopaminergic pathway, affecting motor control via complex changes in the cortico-basal ganglia-thalamic motor network, including the primary motor cortex (M1). The modulation of M1 neuronal activity by dopaminergic inputs, particularly from the ventral tegmental area (VTA) and substantia nigra pars compacta (SNc), plays a crucial role in PD pathophysiology. This study investigates how nigrostriatal dopaminergic degeneration influences M1 neuronal activity in rats using in vivo calcium imaging. Histological analysis confirmed dopaminergic lesion severity, with high lesion level rats showing significant motor deficits. Levodopa treatment improved fine motor abilities, particularly in high lesion level rats. Analysis of M1 calcium signals based on dopaminergic lesion severity revealed distinct M1 activity patterns. Animals with low dopaminergic lesion showed increased calcium events, while high lesion level rats exhibited decreased activity, partially restored by levodopa. These findings suggest that M1 activity is more sensitive to transient fluctuations in dopaminergic transmission, rather than to chronic high or low dopaminergic signaling. This study underscores the complex interplay between dopaminergic signaling and M1 neuronal activity in PD symptoms development. Further research integrating behavioral and calcium imaging data can elucidate mechanisms underlying motor deficits and therapeutic responses in PD.
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Affiliation(s)
| | | | - Shaohua Wang
- National Institute of Environmental Health Sciences
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3
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Plateau V, Baufreton J, Le Bon-Jégo M. Age-Dependent Modulation of Layer V Pyramidal Neuron Excitability in the Mouse Primary Motor Cortex by D1 Receptor Agonists and Antagonists. Neuroscience 2024; 536:21-35. [PMID: 37952579 DOI: 10.1016/j.neuroscience.2023.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 10/31/2023] [Accepted: 11/07/2023] [Indexed: 11/14/2023]
Abstract
The primary motor cortex (M1) receives dopaminergic (DAergic) projections from the midbrain which play a key role in modulating motor and cognitive processes, such as motor skill learning. However, little is known at the level of individual neurons about how dopamine (DA) and its receptors modulate the intrinsic properties of the different neuronal subpopulations in M1 and if this modulation depends on age. Using immunohistochemistry, we first mapped the cells expressing the DA D1 receptor across the different layers in M1, and quantified the number of pyramidal neurons (PNs) expressing the D1 receptor in the different layers, in young and adult mice. This work reveals that the spatial distribution and the molecular profile of D1 receptor-expressing neurons (D1+) across M1 layers do not change with age. Then, combining whole-cell patch-clamp recordings and pharmacology, we explored ex vivo in young and adult mice the impact of activation or blockade of D1 receptors on D1+ PN intrinsic properties. While the bath application of the D1 receptor agonist induced an increase in the excitability of layer V PNs both in young and adult, we identified a distinct modulation of intrinsic electrical properties of layer V D1+ PNs by D1 receptor antagonist depending on the age of the animal.
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Affiliation(s)
- Valentin Plateau
- Université de Bordeaux, Institut des Maladies Neurodégénératives, 33076 Bordeaux, France; CNRS UMR 5293, Institut des Maladies Neurodégénératives, 33076 Bordeaux, France
| | - Jérôme Baufreton
- Université de Bordeaux, Institut des Maladies Neurodégénératives, 33076 Bordeaux, France; CNRS UMR 5293, Institut des Maladies Neurodégénératives, 33076 Bordeaux, France
| | - Morgane Le Bon-Jégo
- Université de Bordeaux, Institut des Maladies Neurodégénératives, 33076 Bordeaux, France; CNRS UMR 5293, Institut des Maladies Neurodégénératives, 33076 Bordeaux, France.
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4
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Braine A, Georges F. Emotion in action: When emotions meet motor circuits. Neurosci Biobehav Rev 2023; 155:105475. [PMID: 37996047 DOI: 10.1016/j.neubiorev.2023.105475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 11/15/2023] [Accepted: 11/17/2023] [Indexed: 11/25/2023]
Abstract
The brain is a remarkably complex organ responsible for a wide range of functions, including the modulation of emotional states and movement. Neuronal circuits are believed to play a crucial role in integrating sensory, cognitive, and emotional information to ultimately guide motor behavior. Over the years, numerous studies employing diverse techniques such as electrophysiology, imaging, and optogenetics have revealed a complex network of neural circuits involved in the regulation of emotional or motor processes. Emotions can exert a substantial influence on motor performance, encompassing both everyday activities and pathological conditions. The aim of this review is to explore how emotional states can shape movements by connecting the neural circuits for emotional processing to motor neural circuits. We first provide a comprehensive overview of the impact of different emotional states on motor control in humans and rodents. In line with behavioral studies, we set out to identify emotion-related structures capable of modulating motor output, behaviorally and anatomically. Neuronal circuits involved in emotional processing are extensively connected to the motor system. These circuits can drive emotional behavior, essential for survival, but can also continuously shape ongoing movement. In summary, the investigation of the intricate relationship between emotion and movement offers valuable insights into human behavior, including opportunities to enhance performance, and holds promise for improving mental and physical health. This review integrates findings from multiple scientific approaches, including anatomical tracing, circuit-based dissection, and behavioral studies, conducted in both animal and human subjects. By incorporating these different methodologies, we aim to present a comprehensive overview of the current understanding of the emotional modulation of movement in both physiological and pathological conditions.
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Affiliation(s)
- Anaelle Braine
- Univ. Bordeaux, CNRS, IMN, UMR 5293, F-33000 Bordeaux, France
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Sugawara SK, Yamamoto T, Nakayama Y, Hamano YH, Fukunaga M, Sadato N, Nishimura Y. Premovement activity in the mesocortical system links peak force but not initiation of force generation under incentive motivation. Cereb Cortex 2023; 33:11408-11419. [PMID: 37814358 PMCID: PMC10690858 DOI: 10.1093/cercor/bhad376] [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: 04/01/2023] [Revised: 09/22/2023] [Accepted: 09/22/2023] [Indexed: 10/11/2023] Open
Abstract
Motivation facilitates motor performance; however, the neural substrates of the psychological effects on motor performance remain unclear. We conducted a functional magnetic resonance imaging experiment while human subjects performed a ready-set-go task with monetary incentives. Although subjects were only motivated to respond quickly, increasing the incentives improved not only reaction time but also peak grip force. However, the trial-by-trial correlation between reaction time and peak grip force was weak. Extensive areas in the mesocortical system, including the ventral midbrain (VM) and cortical motor-related areas, exhibited motivation-dependent activity in the premovement "Ready" period when the anticipated monetary reward was displayed. This premovement activity in the mesocortical system correlated only with subsequent peak grip force, whereas the activity in motor-related areas alone was associated with subsequent reaction time and peak grip force. These findings suggest that the mesocortical system linking the VM and motor-related regions plays a role in controlling the peak of force generation indirectly associated with incentives but not the initiation of force generation.
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Affiliation(s)
- Sho K Sugawara
- Neural Prosthetics Project, Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo 156-8506, Japan
- Section of Brain Function Information, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
- The Graduate University for Advanced Studies, SOKENDAI, Hayama, Kanagawa 340-0193, Japan
| | - Tetsuya Yamamoto
- Section of Brain Function Information, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
| | - Yoshihisa Nakayama
- Neural Prosthetics Project, Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo 156-8506, Japan
| | - Yuki H Hamano
- Section of Brain Function Information, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
| | - Masaki Fukunaga
- Section of Brain Function Information, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
- The Graduate University for Advanced Studies, SOKENDAI, Hayama, Kanagawa 340-0193, Japan
| | - Norihiro Sadato
- Section of Brain Function Information, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
- The Graduate University for Advanced Studies, SOKENDAI, Hayama, Kanagawa 340-0193, Japan
- Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Yukio Nishimura
- Neural Prosthetics Project, Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo 156-8506, Japan
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Frase S, Steddin J, Paschen E, Lenz M, Conforti P, Haas CA, Vlachos A, Schachtrup C, Hosp JA. Dense dopaminergic innervation of the peri-infarct cortex despite dopaminergic cell loss after a pure motor-cortical stroke in rats. J Neurochem 2023; 167:427-440. [PMID: 37735852 DOI: 10.1111/jnc.15970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 08/28/2023] [Accepted: 09/12/2023] [Indexed: 09/23/2023]
Abstract
After ischemic stroke, the cortex directly adjacent to the ischemic core (i.e., the peri-infarct cortex, PIC) undergoes plastic changes that facilitate motor recovery. Dopaminergic signaling is thought to support this process. However, ischemic stroke also leads to the remote degeneration of dopaminergic midbrain neurons, possibly interfering with this beneficial effect. In this study, we assessed the reorganization of dopaminergic innervation of the PIC in a rat model of focal cortical stroke. Adult Sprague-Dawley rats either received a photothrombotic stroke (PTS) in the primary motor cortex (M1) or a sham operation. 30 days after PTS or sham procedure, the retrograde tracer Micro Ruby (MR) was injected into the PIC of stroke animals or into homotopic cortical areas of matched sham rats. Thus, dopaminergic midbrain neurons projecting into the PIC were identified based on MR signal and immunoreactivity against tyrosine hydroxylase (TH), a marker for dopaminergic neurons. The density of dopaminergic innervation within the PIC was assessed by quantification of dopaminergic boutons indicated by TH-immunoreactivity. Regarding postsynaptic processes, expression of dopamine receptors (D1- and D2) and a marker of the functional signal cascade (DARPP-32) were visualized histologically. Despite a 25% ipsilesional loss of dopaminergic midbrain neurons after PTS, the number and spatial distribution of dopaminergic neurons projecting to the PIC was not different compared to sham controls. Moreover, the density of dopaminergic innervation in the PIC was significantly higher than in homotopic cortical areas of the sham group. Within the PIC, D1-receptors were expressed in neurons, whereas D2-receptors were confined to astrocytes. The intensity of D1- and DARPP-32 expression appeared to be higher in the PIC compared to the contralesional homotopic cortex. Our data suggest a sprouting of dopaminergic fibers into the PIC and point to a role for dopaminergic signaling in reparative mechanisms post-stroke, potentially related to recovery.
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Affiliation(s)
- Sibylle Frase
- Department of Neurology and Neuroscience, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Julius Steddin
- Department of Neurology and Neuroscience, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Enya Paschen
- Experimental Epilepsy Research, Department of Neurosurgery, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Maximilian Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Pasquale Conforti
- Department of Molecular Embryology, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Carola A Haas
- Experimental Epilepsy Research, Department of Neurosurgery, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Christian Schachtrup
- Department of Molecular Embryology, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jonas A Hosp
- Department of Neurology and Neuroscience, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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Chen L, Daniels S, Dvorak R, Chu HY. Reduced thalamic excitation to motor cortical pyramidal tract neurons in parkinsonism. SCIENCE ADVANCES 2023; 9:eadg3038. [PMID: 37611096 PMCID: PMC10446482 DOI: 10.1126/sciadv.adg3038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 07/21/2023] [Indexed: 08/25/2023]
Abstract
Degeneration of midbrain dopaminergic (DA) neurons alters the connectivity and functionality of the basal ganglia-thalamocortical circuits in Parkinson's disease (PD). Particularly, the aberrant outputs of the primary motor cortex (M1) contribute to parkinsonian motor deficits. However, cortical adaptations at cellular and synaptic levels in parkinsonism remain poorly understood. Using multidisciplinary approaches, we found that DA degeneration induces cell subtype- and input-specific reduction of thalamic excitation to M1 pyramidal tract (PT) neurons. At molecular level, we identified that N-methyl-d-aspartate (NMDA) receptors play a key role in mediating the reduced thalamocortical excitation to PT neurons. At circuit level, we showed that the reduced thalamocortical transmission in parkinsonian mice can be rescued by chemogenetically suppressing basal ganglia outputs. Together, our data suggest that cell subtype- and synapse-specific adaptations in M1 contribute to altered cortical outputs in parkinsonism and are important aspects of PD pathophysiology.
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Affiliation(s)
- Liqiang Chen
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, MI 49503 USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD, 20815
| | - Samuel Daniels
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, MI 49503 USA
| | - Rachel Dvorak
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, MI 49503 USA
| | - Hong-Yuan Chu
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, MI 49503 USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD, 20815
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Scott DN, Frank MJ. Adaptive control of synaptic plasticity integrates micro- and macroscopic network function. Neuropsychopharmacology 2023; 48:121-144. [PMID: 36038780 PMCID: PMC9700774 DOI: 10.1038/s41386-022-01374-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 06/23/2022] [Accepted: 06/24/2022] [Indexed: 11/09/2022]
Abstract
Synaptic plasticity configures interactions between neurons and is therefore likely to be a primary driver of behavioral learning and development. How this microscopic-macroscopic interaction occurs is poorly understood, as researchers frequently examine models within particular ranges of abstraction and scale. Computational neuroscience and machine learning models offer theoretically powerful analyses of plasticity in neural networks, but results are often siloed and only coarsely linked to biology. In this review, we examine connections between these areas, asking how network computations change as a function of diverse features of plasticity and vice versa. We review how plasticity can be controlled at synapses by calcium dynamics and neuromodulatory signals, the manifestation of these changes in networks, and their impacts in specialized circuits. We conclude that metaplasticity-defined broadly as the adaptive control of plasticity-forges connections across scales by governing what groups of synapses can and can't learn about, when, and to what ends. The metaplasticity we discuss acts by co-opting Hebbian mechanisms, shifting network properties, and routing activity within and across brain systems. Asking how these operations can go awry should also be useful for understanding pathology, which we address in the context of autism, schizophrenia and Parkinson's disease.
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Affiliation(s)
- Daniel N Scott
- Cognitive Linguistic, and Psychological Sciences, Brown University, Providence, RI, USA.
- Carney Institute for Brain Science, Brown University, Providence, RI, USA.
| | - Michael J Frank
- Cognitive Linguistic, and Psychological Sciences, Brown University, Providence, RI, USA.
- Carney Institute for Brain Science, Brown University, Providence, RI, USA.
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Vitrac C, Nallet-Khosrofian L, Iijima M, Rioult-Pedotti MS, Luft A. Endogenous dopamine transmission is crucial for motor skill recovery after stroke. IBRO Neurosci Rep 2022; 13:15-21. [PMID: 35707766 PMCID: PMC9189999 DOI: 10.1016/j.ibneur.2022.05.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 05/31/2022] [Indexed: 11/30/2022] Open
Affiliation(s)
- Clément Vitrac
- Vascular Neurology and Rehabilitation, Department of Neurology, University of Zürich, Switzerland
- Correspondence to: Universitätspital Zürich, Vascular Neurology and Rehabilitation, Rämistrasse 100, 8091 Zürich, Switzerland.
| | | | - Maiko Iijima
- Vascular Neurology and Rehabilitation, Department of Neurology, University of Zürich, Switzerland
| | - Mengia-Seraina Rioult-Pedotti
- Vascular Neurology and Rehabilitation, Department of Neurology, University of Zürich, Switzerland
- Department of MCB, Brown University, Providence, RI, USA
| | - Andreas Luft
- Center for Neurology and Rehabilitation, Vitznau, Switzerland
- Department of Neurology, University Hospital Zürich, Zürich, Switzerland
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Cousineau J, Plateau V, Baufreton J, Le Bon-Jégo M. Dopaminergic modulation of primary motor cortex: From cellular and synaptic mechanisms underlying motor learning to cognitive symptoms in Parkinson's disease. Neurobiol Dis 2022; 167:105674. [PMID: 35245676 DOI: 10.1016/j.nbd.2022.105674] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 02/23/2022] [Accepted: 02/25/2022] [Indexed: 11/16/2022] Open
Abstract
The primary motor cortex (M1) is crucial for movement execution, especially dexterous ones, but also for cognitive functions like motor learning. The acquisition of motor skills to execute dexterous movements requires dopamine-dependent and -independent plasticity mechanisms within M1. In addition to the basal ganglia, M1 is disturbed in Parkinson's disease (PD). However, little is known about how the lack of dopamine (DA), characteristic of PD, directly or indirectly impacts M1 circuitry. Here we review data from studies of PD patients and the substantial research in non-human primate and rodent models of DA depletion. These models enable us to understand the importance of DA in M1 physiology at the behavioral, network, cellular, and synaptic levels. We first summarize M1 functions and neuronal populations in mammals. We then look at the origin of M1 DA and the cellular location of its receptors and explore the impact of DA loss on M1 physiology, motor, and executive functions. Finally, we discuss how PD treatments impact M1 functions.
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11
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Suzuki M, Inoue KI, Nakagawa H, Ishida H, Kobayashi K, Isa T, Takada M, Nishimura Y. A multisynaptic pathway from the ventral midbrain toward spinal motoneurons in monkeys. J Physiol 2022; 600:1731-1752. [PMID: 35122444 PMCID: PMC9306604 DOI: 10.1113/jp282429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 01/10/2022] [Indexed: 12/02/2022] Open
Abstract
Abstract Motivation boosts motor performance. Activity of the ventral midbrain (VM), consisting of the ventral tegmental area (VTA), the substantia nigra pars compacta (SNc) and the retrorubral field (RRF), plays an important role in processing motivation. However, little is known about the neural substrate bridging the VM and the spinal motor output. We hypothesized that the VM might exert a modulatory influence over the descending motor pathways. By retrograde transneuronal labelling with rabies virus, we demonstrated the existence of multisynaptic projections from the VM to the cervical enlargement in monkeys. The distribution pattern of spinal projection neurons in the VM exhibited a caudorostral gradient, in that the RRF and the caudal part of the SNc contained more retrogradely labelled neurons than the VTA and the rostral part of the SNc. Electrical stimulation of the VM induced muscle responses in the contralateral forelimb with a delay of a few milliseconds following the responses of the ipsilateral primary motor cortex (M1). The magnitude and number of evoked muscle responses were associated with the stimulus intensity and number of pulses. The muscle responses were diminished during M1 inactivation. Thus, the present study has identified a multisynaptic VM–spinal pathway that is mediated, at least in part, by the M1 and might play a pivotal role in modulatory control of the spinal motor output. Key points Motivation to obtain reward is thought to boost motor performance, and activity in the ventral midbrain is important to the motivational process. Little is known about a neural substrate bridging the ventral midbrain and the spinal motor output. Retrograde trans‐synaptic experiments revealed that the ventral midbrain projects multisynaptically to the spinal cord in macaque monkeys. Ventral midbrain activation by electrical stimulation generated cortical activity in the motor cortex and forelimb muscle activity. A multisynaptic ventral midbrain–spinal pathway most probably plays a pivotal role in modulatory control of the spinal motor output.
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Affiliation(s)
- Michiaki Suzuki
- Neural Prosthetics Project, Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo, 156-8506, Japan.,Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8585, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa, 240-0193, Japan
| | - Ken-Ichi Inoue
- Systems Neuroscience Section, Primate Research Institute, Kyoto University, Inuyama, Aichi, 484-8506, Japan
| | - Hiroshi Nakagawa
- Systems Neuroscience Section, Primate Research Institute, Kyoto University, Inuyama, Aichi, 484-8506, Japan.,Present address: Department of Molecular Neuroscience, World Premier International Immunology Frontier Research Center, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Hiroaki Ishida
- Neural Prosthetics Project, Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo, 156-8506, Japan.,Present address: Schizophrenia Research Project, Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo, 156-8506, Japan
| | - Kenta Kobayashi
- Section of Viral Vector Development, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8585, Japan
| | - Tadashi Isa
- Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8585, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa, 240-0193, Japan.,Section of Viral Vector Development, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8585, Japan.,Department of Neuroscience, Graduate School of Medicine, Kyoto University, Sakyo, Kyoto, 606-8501, Japan.,Institute for the Advanced Study of Human Biology (WPI-ASHBi), Kyoto University, Sakyo, Kyoto, 606-8501, Japan
| | - Masahiko Takada
- Systems Neuroscience Section, Primate Research Institute, Kyoto University, Inuyama, Aichi, 484-8506, Japan
| | - Yukio Nishimura
- Neural Prosthetics Project, Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo, 156-8506, Japan.,Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8585, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa, 240-0193, Japan
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12
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Gugula A, Trenk A, Celary A, Cizio K, Tylko G, Blasiak A, Hess G. Early-life stress modifies the reactivity of neurons in the ventral tegmental area and lateral hypothalamus to acute stress in female rats. Neuroscience 2022; 490:49-65. [DOI: 10.1016/j.neuroscience.2022.02.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 01/29/2022] [Accepted: 02/14/2022] [Indexed: 10/19/2022]
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13
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Macedo-Lima M, Remage-Healey L. Dopamine Modulation of Motor and Sensory Cortical Plasticity among Vertebrates. Integr Comp Biol 2021; 61:316-336. [PMID: 33822047 PMCID: PMC8600016 DOI: 10.1093/icb/icab019] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Goal-directed learning is a key contributor to evolutionary fitness in animals. The neural mechanisms that mediate learning often involve the neuromodulator dopamine. In higher order cortical regions, most of what is known about dopamine's role is derived from brain regions involved in motivation and decision-making, while significantly less is known about dopamine's potential role in motor and/or sensory brain regions to guide performance. Research on rodents and primates represents over 95% of publications in the field, while little beyond basic anatomy is known in other vertebrate groups. This significantly limits our general understanding of how dopamine signaling systems have evolved as organisms adapt to their environments. This review takes a pan-vertebrate view of the literature on the role of dopamine in motor/sensory cortical regions, highlighting, when available, research on non-mammalian vertebrates. We provide a broad perspective on dopamine function and emphasize that dopamine-induced plasticity mechanisms are widespread across all cortical systems and associated with motor and sensory adaptations. The available evidence illustrates that there is a strong anatomical basis-dopamine fibers and receptor distributions-to hypothesize that pallial dopamine effects are widespread among vertebrates. Continued research progress in non-mammalian species will be crucial to further our understanding of how the dopamine system evolved to shape the diverse array of brain structures and behaviors among the vertebrate lineage.
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Affiliation(s)
- Matheus Macedo-Lima
- Neuroscience and Behavior Program, Center for Neuroendocrine Studies, University of Massachusetts Amherst, Amherst, MA 01003, USA
- CAPES Foundation, Ministry of Education of Brazil, 70040-031 Brasília, Brazil
| | - Luke Remage-Healey
- Neuroscience and Behavior Program, Center for Neuroendocrine Studies, University of Massachusetts Amherst, Amherst, MA 01003, USA
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14
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Chen L, Daniels S, Kim Y, Chu HY. Cell Type-Specific Decrease of the Intrinsic Excitability of Motor Cortical Pyramidal Neurons in Parkinsonism. J Neurosci 2021; 41:5553-5565. [PMID: 34006589 PMCID: PMC8221604 DOI: 10.1523/jneurosci.2694-20.2021] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 05/03/2021] [Accepted: 05/05/2021] [Indexed: 11/21/2022] Open
Abstract
The hypokinetic motor symptoms of Parkinson's disease (PD) are closely linked with a decreased motor cortical output as a consequence of elevated basal ganglia inhibition. However, whether and how the loss of dopamine (DA) alters the cellular properties of motor cortical neurons in PD remains undefined. We induced parkinsonism in adult C57BL/6 mice of both sexes by injecting neurotoxin, 6-hydroxydopamine (6-OHDA), into the medial forebrain bundle. By using ex vivo patch-clamp recording and retrograde tracing approach, we found that the intrinsic excitability of pyramidal tract neurons (PTNs) in the primary motor cortical (M1) layer (L)5b was greatly decreased in parkinsonism; but the intratelencephalic neurons (ITNs) were not affected. The cell type-specific intrinsic adaptations were associated with a depolarized threshold and broadened width of action potentials (APs) in PTNs. Moreover, the loss of midbrain dopaminergic neurons impaired the capability of M1 PTNs to sustain high-frequency firing, which could underlie their abnormal pattern of activity in the parkinsonian state. We also showed that the decreased excitability in parkinsonism was caused by an impaired function of both persistent sodium channels and the large conductance, Ca2+-activated K+ channels. Acute activation of dopaminergic receptors failed to rescue the impaired intrinsic excitability of M1 PTNs in parkinsonian mice. Altogether, our data demonstrated a cell type-specific decrease of the excitability of M1 pyramidal neurons in parkinsonism. Thus, intrinsic adaptations in the motor cortex provide novel insight in our understanding of the pathophysiology of motor deficits in PD.SIGNIFICANCE STATEMENT The degeneration of midbrain dopaminergic neurons in Parkinson's disease (PD) remodels the connectivity and function of cortico-basal ganglia-thalamocortical network. However, whether and how dopaminergic degeneration and the associated basal ganglia dysfunction alter motor cortical circuitry remain undefined. We found that pyramidal neurons in the layer (L)5b of the primary motor cortex (M1) exhibit distinct adaptations in response to the loss of midbrain dopaminergic neurons, depending on their long-range projections. Besides the decreased thalamocortical synaptic excitation as proposed by the classical model of Parkinson's pathophysiology, these results, for the first time, show novel cellular and molecular mechanisms underlying the abnormal motor cortical output in parkinsonism.
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Affiliation(s)
- Liqiang Chen
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, Michigan 49503
| | - Samuel Daniels
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, Michigan 49503
| | - Yerim Kim
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, Michigan 49503
| | - Hong-Yuan Chu
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, Michigan 49503
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15
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Primary motor cortex in Parkinson's disease: Functional changes and opportunities for neurostimulation. Neurobiol Dis 2020; 147:105159. [PMID: 33152506 DOI: 10.1016/j.nbd.2020.105159] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 10/30/2020] [Accepted: 10/31/2020] [Indexed: 02/07/2023] Open
Abstract
Movement abnormalities of Parkinson's disease (PD) arise from disordered neural activity in multiple interconnected brain structures. The planning and execution of movement requires recruitment of a heterogeneous collection of pyramidal projection neurons in the primary motor cortex (M1). The neural representations of movement in M1 single-cell and field potential recordings are directly and indirectly influenced by the midbrain dopaminergic neurons that degenerate in PD. This review examines M1 functional alterations in PD as uncovered by electrophysiological recordings and neurostimulation studies in patients and experimental animal models. Dysfunction of the parkinsonian M1 depends on the severity and/or duration of dopamine-depletion and the species examined, and is expressed as alterations in movement-related firing dynamics; functional reorganisation of local circuits; and changes in field potential beta oscillations. Neurostimulation methods that modulate M1 activity directly (e.g., transcranial magnetic stimulation) or indirectly (subthalamic nucleus deep brain stimulation) improve motor function in PD patients, showing that targeted neuromodulation of M1 is a realistic therapy. We argue that the therapeutic profile of M1 neurostimulation is likely to be greatly enhanced with alternative technologies that permit cell-type specific control and incorporate feedback from electrophysiological biomarkers measured locally.
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16
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Dopamine D2-Like Receptors Modulate Intrinsic Properties and Synaptic Transmission of Parvalbumin Interneurons in the Mouse Primary Motor Cortex. eNeuro 2020; 7:ENEURO.0081-20.2020. [PMID: 32321772 PMCID: PMC7240291 DOI: 10.1523/eneuro.0081-20.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 03/10/2020] [Indexed: 02/07/2023] Open
Abstract
Dopamine (DA) plays a crucial role in the control of motor and higher cognitive functions such as learning, working memory, and decision making. The primary motor cortex (M1), which is essential for motor control and the acquisition of motor skills, receives dopaminergic inputs in its superficial and deep layers from the midbrain. However, the precise action of DA and DA receptor subtypes on the cortical microcircuits of M1 remains poorly understood. The aim of this work was to investigate in mice how DA, through the activation of D2-like receptors (D2Rs), modulates the cellular and synaptic activity of M1 parvalbumin-expressing interneurons (PVINs) which are crucial to regulate the spike output of pyramidal neurons (PNs). By combining immunofluorescence, ex vivo electrophysiology, pharmacology and optogenetics approaches, we show that D2R activation increases neuronal excitability of PVINs and GABAergic synaptic transmission between PVINs and PNs in Layer V of M1. Our data reveal how cortical DA modulates M1 microcircuitry, which could be important in the acquisition of motor skills.
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17
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Hosp JA, Greiner KL, Martinez Arellano L, Roth F, Löffler F, Reis J, Fritsch B. Progressive secondary exo-focal dopaminergic neurodegeneration occurs in not directly connected midbrain nuclei after pure motor-cortical stroke. Exp Neurol 2020; 327:113211. [PMID: 31987834 DOI: 10.1016/j.expneurol.2020.113211] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 01/20/2020] [Accepted: 01/24/2020] [Indexed: 10/25/2022]
Abstract
Transsynaptic anterograde and retrograde degeneration of neurons and neural fibers are assumed to trigger local excitotoxicity and inflammatory processes. These processes in turn are thought to drive exo-focal neurodegeneration in remote areas connected to the infarcted tissue after ischemic stroke. In the case of middle cerebral artery occlusion (MCAO), in which striato-nigral connections are affected, the hypothesis of inflammation-induced remote neurodegeneration is based on the temporal dynamics of an early appearance of inflammatory markers in midbrain followed by dopaminergic neuronal loss. To test the hypothesis of a direct transsynaptic mediation of secondary exo-focal post-ischemic neurodegeneration, we used a photochemical induction of a stroke (PTS) in Sprague-Dawley rats restricted to motor cortex (MC), thereby sparing the striatal connections to dopaminergic midbrain nuclei. To dissect the temporal dynamics of post-ischemic neurodegeneration, we analyzed brain sections harvested at day 7 and 14 post stroke. Here, an unexpectedly pronounced and widespread loss of dopaminergic neurons occurred 14 days after stroke also affecting dopaminergic nuclei that are not directly coupled to MC. Since the pattern of neurodegeneration in case of a pure motor stroke is similar to a major stroke including the striatum, it is unlikely that direct synaptic coupling is a prerequisite for delayed secondary exo-focal post ischemic neurodegeneration. Furthermore, dopaminergic neurodegeneration was already detected by Fluoro-Jade C staining at day 7, coinciding with a solely slight inflammatory response. Thus, inflammation cannot be assumed to be the primary driver of exo-focal post-ischemic cell death. Moreover, nigral substance P (SP) expression indicated intact striato-nigral innervation after PTS, whereas opposing effects on SP expression after striatal infarcts argue against a critical role of SP in neurodegenerative or inflammatory processes during exo-focal neurodegeneration.
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Affiliation(s)
- J A Hosp
- Department of Neurology and Neuroscience, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
| | - K L Greiner
- Department of Neurology and Neuroscience, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - L Martinez Arellano
- Department of Neurology and Neuroscience, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - F Roth
- Department of Neurology and Neuroscience, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - F Löffler
- Department of Neurology and Neuroscience, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - J Reis
- Department of Neurology and Neuroscience, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - B Fritsch
- Department of Neurology and Neuroscience, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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18
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Hosp JA, Coenen VA, Rijntjes M, Egger K, Urbach H, Weiller C, Reisert M. Ventral tegmental area connections to motor and sensory cortical fields in humans. Brain Struct Funct 2019; 224:2839-2855. [PMID: 31440906 PMCID: PMC6778584 DOI: 10.1007/s00429-019-01939-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Accepted: 08/10/2019] [Indexed: 12/13/2022]
Abstract
In humans, sensorimotor cortical areas receive relevant dopaminergic innervation—although an anatomic description of the underlying fiber projections is lacking so far. In general, dopaminergic projections towards the cortex originate within the ventral tegmental area (VTA) and are organized in a meso-cortico-limbic system. Using a DTI-based global tractography approach, we recently characterized the superolateral branch of the medial forebrain bundle (slMFB), a prominent pathway providing dopaminergic (and other transmitters) innervation for the pre-frontal cortex (Coenen et al., NeuroImage Clin 18:770–783, 2018). To define the connections between VTA and sensory–motor cortical fields that should contain dopaminergic fibers, we use the slMFB as a key structure to lead our fiber selection procedure: using a similar tracking-seed and tractography algorithm, we describe a dorsal extension of this slMFB that covers sensorimotor fields that are dorsally appended to pre-frontal cortical areas. This “motorMFB”, that connects the VTA to sensorimotor cortical fields, can be further segregated into three sub-bundles with a seed-based fiber-selection strategy: A PFC bundle that is attendant to the pre-frontal cortex, passes the lateral VTA, runs through the border zone between the posterior and lateral ventral thalamic nucleus, and involves the pre- and postcentral gyrus. An MB bundle that is attendant to the mammillary bodies runs directly through the medial VTA, passes the lateral ventral thalamic nucleus, and involves the pre- and postcentral gyrus as well as the supplementary motor area (SMA) and the dorsal premotor cortex (dPMC). Finally, a BC bundle that is attendant to the brainstem and cerebellum runs through the lateral VTA, passes the anterior ventral thalamic nucleus, and covers the SMA, pre-SMA, and the dPMC. We, furthermore, included a fiber tracking of the well-defined dentato-rubro-thalamic tract (DRT) that is known to lie in close proximity with respect to fiber orientation and projection areas. As expected, the tract is characterized by a decussation at the ponto-mesencephal level and a projection covering the superior-frontal and precentral cortex. In addition to the physiological role of these particular bundles, the physiological and pathophysiological impact of dopaminergic signaling within sensorimotor cortical fields becomes discussed. However, some limitations have to be taken into account in consequence of the method: the transmitter content, the directionality, and the occurrence of interposed synaptic contacts cannot be specified.
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Affiliation(s)
- Jonas A Hosp
- Department of Neurology and Neuroscience, Freiburg University Medical Center, Breisacher Str. 64, 79106, Freiburg, Germany. .,Faculty of Medicine, University of Freiburg, Freiburg, Germany.
| | - V A Coenen
- Department of Stereotactic and Functional Neurosurgery, Freiburg University Medical Center, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Basics in Neuromodulation, University of Freiburg, Freiburg, Germany
| | - M Rijntjes
- Department of Neurology and Neuroscience, Freiburg University Medical Center, Breisacher Str. 64, 79106, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - K Egger
- Department of Neuroradiology, Freiburg University Medical Center, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - H Urbach
- Department of Neuroradiology, Freiburg University Medical Center, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - C Weiller
- Department of Neurology and Neuroscience, Freiburg University Medical Center, Breisacher Str. 64, 79106, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - M Reisert
- Department of Stereotactic and Functional Neurosurgery, Freiburg University Medical Center, Freiburg, Germany.,Department of Medical Physics, Freiburg University Medical Center, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
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19
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Enhanced CRFR1-Dependent Regulation of a Ventral Tegmental Area to Prelimbic Cortex Projection Establishes Susceptibility to Stress-Induced Cocaine Seeking. J Neurosci 2018; 38:10657-10671. [PMID: 30355627 DOI: 10.1523/jneurosci.2080-18.2018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 09/28/2018] [Accepted: 10/15/2018] [Indexed: 11/21/2022] Open
Abstract
The ability of stress to trigger cocaine seeking in humans and rodents is variable and is determined by the amount and pattern of prior drug use. This study examined the role of a corticotropin releasing factor (CRF)-regulated dopaminergic projection from the ventral tegmental area (VTA) to the prelimbic cortex in shock-induced cocaine seeking and its recruitment under self-administration conditions that establish relapse vulnerability. Male rats with a history of daily long-access (LgA; 14 × 6 h/d) but not short-access (ShA; 14 × 2 h/d) self-administration showed robust shock-induced cocaine seeking. This was associated with a heightened shock-induced prelimbic cortex Fos response and activation of cholera toxin b retro-labeled VTA neurons that project to the prelimbic cortex. Chemogenetic inhibition of this pathway using a dual virus intersectional hM4Di DREADD (designer receptor exclusively activated by designer drug) based approach prevented shock-induced cocaine seeking. Both shock-induced reinstatement and the prelimbic cortex Fos response were prevented by bilateral intra-VTA injections of the CRF receptor 1 (CRFR1) antagonist, antalarmin. Moreover, pharmacological disconnection of the CRF-regulated dopaminergic projection to the prelimbic cortex by injection of antalarmin into the VTA in one hemisphere and the D1 receptor antagonist, SCH23390, into the prelimbic cortex of the contralateral hemisphere prevented shock-induced cocaine seeking. Finally, LgA, but not ShA, cocaine self-administration resulted in increased VTA CRFR1 mRNA levels as measured using in situ hybridization. Altogether, these findings suggest that excessive cocaine use may establish susceptibility to stress-induced relapse by recruiting CRF regulation of a stressor-responsive mesocortical dopaminergic pathway.SIGNIFICANCE STATEMENT Understanding the neural pathways and mechanisms through which stress triggers relapse to cocaine use is critical for the development of more effective treatment approaches. Prior work has demonstrated a critical role for the neuropeptide corticotropin releasing factor (CRF) in stress-induced cocaine seeking. Here we provide evidence that stress-induced reinstatement in a rat model of relapse is mediated by a CRF-regulated dopaminergic projection from the ventral tegmental area (VTA) that activates dopamine D1 receptors in the prelimbic cortex. Moreover, we report that this pathway may be recruited as a result of daily cocaine self-administration under conditions of extended drug access/heightened drug intake, likely as a result of increased CRFR1 expression in the VTA, thereby promoting susceptibility to stress-induced cocaine seeking.
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20
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Leemburg S, Canonica T, Luft A. Motor skill learning and reward consumption differentially affect VTA activation. Sci Rep 2018; 8:687. [PMID: 29330488 PMCID: PMC5766527 DOI: 10.1038/s41598-017-18716-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 12/15/2017] [Indexed: 11/16/2022] Open
Abstract
Dopamine release from the ventral tegmental area (VTA) terminals in the primary motor cortex (M1) enables motor skill acquisition. Here, we test the hypothesis that dopaminergic VTA neurons projecting to M1 are activated when rewards are obtained during motor skill acquisition, but not during task execution at plateau performance, or by rewards obtained without performing skilled movements. Rats were trained to perform a skilled reaching task for 3 days (acquisition) or 7 days (plateau). In combination with retrograde labelling of VTA-to-M1 projection neurons, double immunofluorescence for c-fos and tyrosine hydroxylase (TH) was used to assess activation of dopaminergic and non-dopaminergic VTA neurons. Dopaminergic VTA-to-M1 projection neurons were indeed activated during successful motor skill acquisition, but not when rats failed to learn or had reached plateau performance, nor by food rewards alone. By contrast, dopaminergic VTA neurons that did not project to M1 were activated by both skilled reaching and food rewards. Non-dopaminergic neurons were found to be activated by motor task performance at plateau, but not during skill acquisition. These results indicate that distinct populations of VTA neurons are activated by motor skill acquisition and task performance. Moreover, this activation is not merely related to consumption of food rewards.
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Affiliation(s)
- Susan Leemburg
- Division of Vascular Neurology and Rehabilitation, Department of Neurology, University Hospital Zurich, Zurich, Switzerland
| | - Tara Canonica
- Division of Vascular Neurology and Rehabilitation, Department of Neurology, University Hospital Zurich, Zurich, Switzerland.,College of Biomedical and Life Sciences, School of Psychology, Cardiff University, Cardiff, United Kingdom
| | - Andreas Luft
- Division of Vascular Neurology and Rehabilitation, Department of Neurology, University Hospital Zurich, Zurich, Switzerland. .,Cereneo Center for Neurology and Rehabilitation, Vitznau, Switzerland.
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21
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Substance P signalling in primary motor cortex facilitates motor learning in rats. PLoS One 2017; 12:e0189812. [PMID: 29281692 PMCID: PMC5744944 DOI: 10.1371/journal.pone.0189812] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 12/01/2017] [Indexed: 01/17/2023] Open
Abstract
Among the genes that are up-regulated in response to a reaching training in rats, Tachykinin 1 (Tac1)-a gene that encodes the neuropeptide Substance P (Sub P)-shows an especially strong expression. Using Real-Time RT-PCR, a detailed time-course of Tac1 expression could be defined: a significant peak occurs 7 hours after training ended at the first and second training session, whereas no up-regulation could be detected at a later time-point (sixth training session). To assess the physiological role of Sub P during movement acquisition, microinjections into the primary motor cortex (M1) contralateral to the trained paw were performed. When Sub P was injected before the first three sessions of a reaching training, effectiveness of motor learning became significantly increased. Injections at a time-point when rats already knew the task (i.e. training session ten and eleven) had no effect on reaching performance. Sub P injections did not influence the improvement of performance within a single training session, but retention of performance between sessions became strengthened at a very early stage (i.e. between baseline-training and first training session). Thus, Sub P facilitates motor learning in the very early phase of skill acquisition by supporting memory consolidation. In line with these findings, learning related expression of the precursor Tac1 occurs at early but not at later time-points during reaching training.
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22
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Vitrac C, Benoit-Marand M. Monoaminergic Modulation of Motor Cortex Function. Front Neural Circuits 2017; 11:72. [PMID: 29062274 PMCID: PMC5640772 DOI: 10.3389/fncir.2017.00072] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Accepted: 09/19/2017] [Indexed: 01/09/2023] Open
Abstract
Elaboration of appropriate responses to behavioral situations rests on the ability of selecting appropriate motor outcomes in accordance to specific environmental inputs. To this end, the primary motor cortex (M1) is a key structure for the control of voluntary movements and motor skills learning. Subcortical loops regulate the activity of the motor cortex and thus contribute to the selection of appropriate motor plans. Monoamines are key mediators of arousal, attention and motivation. Their firing pattern enables a direct encoding of different states thus promoting or repressing the selection of actions adapted to the behavioral context. Monoaminergic modulation of motor systems has been extensively studied in subcortical circuits. Despite evidence of converging projections of multiple neurotransmitters systems in the motor cortex pointing to a direct modulation of local circuits, their contribution to the execution and learning of motor skills is still poorly understood. Monoaminergic dysregulation leads to impaired plasticity and motor function in several neurological and psychiatric conditions, thus it is critical to better understand how monoamines modulate neural activity in the motor cortex. This review aims to provide an update of our current understanding on the monoaminergic modulation of the motor cortex with an emphasis on motor skill learning and execution under physiological conditions.
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Affiliation(s)
- Clément Vitrac
- Laboratoire de Neurosciences Expérimentales et Cliniques, INSERM U1084, Poitiers, France.,Laboratoire de Neurosciences Expérimentales et Cliniques, Université de Poitiers, Poitiers, France
| | - Marianne Benoit-Marand
- Laboratoire de Neurosciences Expérimentales et Cliniques, INSERM U1084, Poitiers, France.,Laboratoire de Neurosciences Expérimentales et Cliniques, Université de Poitiers, Poitiers, France
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23
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Ramakrishnan A, Byun YW, Rand K, Pedersen CE, Lebedev MA, Nicolelis MAL. Cortical neurons multiplex reward-related signals along with sensory and motor information. Proc Natl Acad Sci U S A 2017; 114:E4841-E4850. [PMID: 28559307 PMCID: PMC5474796 DOI: 10.1073/pnas.1703668114] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Rewards are known to influence neural activity associated with both motor preparation and execution. This influence can be exerted directly upon the primary motor (M1) and somatosensory (S1) cortical areas via the projections from reward-sensitive dopaminergic neurons of the midbrain ventral tegmental areas. However, the neurophysiological manifestation of reward-related signals in M1 and S1 are not well understood. Particularly, it is unclear how the neurons in these cortical areas multiplex their traditional functions related to the control of spatial and temporal characteristics of movements with the representation of rewards. To clarify this issue, we trained rhesus monkeys to perform a center-out task in which arm movement direction, reward timing, and magnitude were manipulated independently. Activity of several hundred cortical neurons was simultaneously recorded using chronically implanted microelectrode arrays. Many neurons (9-27%) in both M1 and S1 exhibited activity related to reward anticipation. Additionally, neurons in these areas responded to a mismatch between the reward amount given to the monkeys and the amount they expected: A lower-than-expected reward caused a transient increase in firing rate in 60-80% of the total neuronal sample, whereas a larger-than-expected reward resulted in a decreased firing rate in 20-35% of the neurons. Moreover, responses of M1 and S1 neurons to reward omission depended on the direction of movements that led to those rewards. These observations suggest that sensorimotor cortical neurons corepresent rewards and movement-related activity, presumably to enable reward-based learning.
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Affiliation(s)
- Arjun Ramakrishnan
- Department of Neurobiology, Duke University, Durham, NC 27710
- Duke University Center for Neuroengineering, Duke University, Durham, NC 27710
| | - Yoon Woo Byun
- Duke University Center for Neuroengineering, Duke University, Durham, NC 27710
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
| | - Kyle Rand
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
| | - Christian E Pedersen
- Joint Department of Biomedical Engineering, University of North Carolina-Chapel Hill and North Carolina State University, Raleigh, NC 27695
| | - Mikhail A Lebedev
- Department of Neurobiology, Duke University, Durham, NC 27710
- Duke University Center for Neuroengineering, Duke University, Durham, NC 27710
| | - Miguel A L Nicolelis
- Department of Neurobiology, Duke University, Durham, NC 27710;
- Duke University Center for Neuroengineering, Duke University, Durham, NC 27710
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
- Department of Psychology and Neuroscience, Duke University, Durham, NC 27708
- Department of Neurology, Duke University, Durham, NC 27710
- Edmund and Lily Safra International Institute of Neurosciences, Natal 59066060, Brazil
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24
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de Paiva JPQ, Magalhães SC, do Prado GF, Eckeli AL, Kaelin-Lang A, Conforto AB. The duration of the cortical silent period is not abnormal in Restless Legs Syndrome/Willis-Ekbom Disease. J Neurol Sci 2017; 375:35-42. [PMID: 28320166 DOI: 10.1016/j.jns.2016.12.066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 11/28/2016] [Accepted: 12/28/2016] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To compare the duration of the cortical silent period (CSP) measured in a hand muscle in subjects with primary Restless Legs Syndrome (RLS/WED) and controls, using four different methods of analysis. METHODS The CSP to transcranial magnetic stimulation of the dominant motor cortex was assessed in the abductor digiti minimi of 33 subjects with RLS/WED and 24 controls. CSP duration was measured by an automated and three visually-guided methods. RESULTS There were significant differences between absolute values of CSP duration according to the method of analysis. However, irrespectively of the method used for CSP assessment, no differences were found between measurements performed in subjects with RLS/WED and subjects from the control group. CONCLUSIONS Absolute values of CSP durations analyzed by different methods should not be directly compared, because significantly different results can be obtained from the same data set. SIGNIFICANCE The CSP assessed from a hand muscle is unlikely to be a biomarker of primary RLS/WED. Our results highlight the importance of standardizing the definition of CSP onset and offset, as well as of describing in detail the methodology chosen to record and measure CSP duration, in order to enable comparisons between studies.
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Affiliation(s)
- Joselisa Péres Queiroz de Paiva
- Hospital Israelita Albert Einstein, Edifício Josef Féher (Bloco A), 2° subsolo, Av. Albert Einstein, 627/701, São Paulo, SP, Brazil CEP: 05652-900.
| | - Samir Câmara Magalhães
- Hospital Israelita Albert Einstein, Edifício Josef Féher (Bloco A), 2° subsolo, Av. Albert Einstein, 627/701, São Paulo, SP, Brazil CEP: 05652-900.
| | - Gilmar Fernandes do Prado
- Universidade Federal de São Paulo, Departamento de Neurologia e Neurocirurgia, Rua Claúdio Rossi, 394, São Paulo, SP, Brazil CEP: 01547-000.
| | - Alan Luiz Eckeli
- Hospital das Clínicas da Faculdade de Medicina, Departamento de Neurociências e Ciências do Comportamento, Divisão de Neurologia, Hospital das Clinicas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil CEP: 14.048-900.
| | - Alain Kaelin-Lang
- Neurocenter of Southern Switzerland, LBN - Laboratory for Biomedical Neurosciences, 6900 Lugano, Switzerland.
| | - Adriana Bastos Conforto
- Hospital Israelita Albert Einstein, Edifício Josef Féher (Bloco A), 2° subsolo, Av. Albert Einstein, 627/701, São Paulo, SP, Brazil CEP: 05652-900; Hospital das Clínicas da Faculdade de Medicina, Departamento de Neurologia e Núcleo de Apoio à Pesquisa em Neurociência Aplicada (NAPNA), Universidade de São Paulo, São Paulo, SP, Brazil CEP: 05403-010.
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25
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Kimura R, Saiki A, Fujiwara-Tsukamoto Y, Sakai Y, Isomura Y. Large-scale analysis reveals populational contributions of cortical spike rate and synchrony to behavioural functions. J Physiol 2016; 595:385-413. [PMID: 27488936 DOI: 10.1113/jp272794] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 08/01/2016] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS There have been few systematic population-wide analyses of relationships between spike synchrony within a period of several milliseconds and behavioural functions. In this study, we obtained a large amount of spike data from > 23,000 neuron pairs by multiple single-unit recording from deep layer neurons in motor cortical areas in rats performing a forelimb movement task. The temporal changes of spike synchrony in the whole neuron pairs were statistically independent of behavioural changes during the task performance, although some neuron pairs exhibited correlated changes in spike synchrony. Mutual information analyses revealed that spike synchrony made a smaller contribution than spike rate to behavioural functions. The strength of spike synchrony between two neurons was statistically independent of the spike rate-based preferences of the pair for behavioural functions. ABSTRACT Spike synchrony within a period of several milliseconds in presynaptic neurons enables effective integration of functional information in the postsynaptic neuron. However, few studies have systematically analysed the population-wide relationships between spike synchrony and behavioural functions. Here we obtained a sufficiently large amount of spike data among regular-spiking (putatively excitatory) and fast-spiking (putatively inhibitory) neuron subtypes (> 23,000 pairs) by multiple single-unit recording from deep layers in motor cortical areas (caudal forelimb area, rostral forelimb area) in rats performing a forelimb movement task. After holding a lever, rats pulled the lever either in response to a cue tone (external-trigger trials) or spontaneously without any cue (internal-trigger trials). Many neurons exhibited functional spike activity in association with forelimb movements, and the preference of regular-spiking neurons in the rostral forelimb area was more biased toward externally triggered movement than that in the caudal forelimb area. We found that a population of neuron pairs with spike synchrony does exist, and that some neuron pairs exhibit a dependence on movement phase during task performance. However, the population-wide analysis revealed that spike synchrony was statistically independent of the movement phase and the spike rate-based preferences of the pair for behavioural functions, whereas spike rates were clearly dependent on the movement phase. In fact, mutual information analyses revealed that the contribution of spike synchrony to the behavioural functions was small relative to the contribution of spike rate. Our large-scale analysis revealed that cortical spike rate, rather than spike synchrony, contributes to population coding for movement.
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Affiliation(s)
- Rie Kimura
- Brain Science Institute, Tamagawa University, Tokyo, Japan.,JST CREST, Tokyo, Japan.,Division of Visual Information Processing, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Japan.,Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan
| | - Akiko Saiki
- Brain Science Institute, Tamagawa University, Tokyo, Japan.,JST CREST, Tokyo, Japan
| | - Yoko Fujiwara-Tsukamoto
- Brain Science Institute, Tamagawa University, Tokyo, Japan.,JST CREST, Tokyo, Japan.,Laboratory of Neural Circuitry, Graduate School of Brain Science, Doshisha University, Kyoto, Japan.,Present address: Faculty of Human Life Studies, Department of Food and Nutrition, Hagoromo University of International Studies, Osaka, Japan
| | - Yutaka Sakai
- Brain Science Institute, Tamagawa University, Tokyo, Japan.,JST CREST, Tokyo, Japan
| | - Yoshikazu Isomura
- Brain Science Institute, Tamagawa University, Tokyo, Japan.,JST CREST, Tokyo, Japan
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Barker DJ, Root DH, Zhang S, Morales M. Multiplexed neurochemical signaling by neurons of the ventral tegmental area. J Chem Neuroanat 2016; 73:33-42. [PMID: 26763116 PMCID: PMC4818729 DOI: 10.1016/j.jchemneu.2015.12.016] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 12/31/2015] [Accepted: 12/31/2015] [Indexed: 12/15/2022]
Abstract
The ventral tegmental area (VTA) is an evolutionarily conserved structure that has roles in reward-seeking, safety-seeking, learning, motivation, and neuropsychiatric disorders such as addiction and depression. The involvement of the VTA in these various behaviors and disorders is paralleled by its diverse signaling mechanisms. Here we review recent advances in our understanding of neuronal diversity in the VTA with a focus on cell phenotypes that participate in 'multiplexed' neurotransmission involving distinct signaling mechanisms. First, we describe the cellular diversity within the VTA, including neurons capable of transmitting dopamine, glutamate or GABA as well as neurons capable of multiplexing combinations of these neurotransmitters. Next, we describe the complex synaptic architecture used by VTA neurons in order to accommodate the transmission of multiple transmitters. We specifically cover recent findings showing that VTA multiplexed neurotransmission may be mediated by either the segregation of dopamine and glutamate into distinct microdomains within a single axon or by the integration of glutamate and GABA into a single axon terminal. In addition, we discuss our current understanding of the functional role that these multiplexed signaling pathways have in the lateral habenula and the nucleus accumbens. Finally, we consider the putative roles of VTA multiplexed neurotransmission in synaptic plasticity and discuss how changes in VTA multiplexed neurons may relate to various psychopathologies including drug addiction and depression.
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Affiliation(s)
- David J Barker
- Neuronal Networks Section, Integrative Neuroscience Research Branch, National Institute on Drug Abuse, 251 Bayview Blvd Suite 200, Baltimore, MD 21224, United States
| | - David H Root
- Neuronal Networks Section, Integrative Neuroscience Research Branch, National Institute on Drug Abuse, 251 Bayview Blvd Suite 200, Baltimore, MD 21224, United States
| | - Shiliang Zhang
- Neuronal Networks Section, Integrative Neuroscience Research Branch, National Institute on Drug Abuse, 251 Bayview Blvd Suite 200, Baltimore, MD 21224, United States
| | - Marisela Morales
- Neuronal Networks Section, Integrative Neuroscience Research Branch, National Institute on Drug Abuse, 251 Bayview Blvd Suite 200, Baltimore, MD 21224, United States.
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Aransay A, Rodríguez-López C, García-Amado M, Clascá F, Prensa L. Long-range projection neurons of the mouse ventral tegmental area: a single-cell axon tracing analysis. Front Neuroanat 2015; 9:59. [PMID: 26042000 PMCID: PMC4436899 DOI: 10.3389/fnana.2015.00059] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 04/24/2015] [Indexed: 11/20/2022] Open
Abstract
Pathways arising from the ventral tegmental area (VTA) release dopamine and other neurotransmitters during the expectation and achievement of reward, and are regarded as central links of the brain networks that create drive, pleasure, and addiction. While the global pattern of VTA projections is well-known, the actual axonal wiring of individual VTA neurons had never been investigated. Here, we labeled and analyzed the axons of 30 VTA single neurons by means of single-cell transfection with the Sindbis-pal-eGFP vector in mice. These observations were complemented with those obtained by labeling the axons of small populations of VTA cells with iontophoretic microdeposits of biotinylated dextran amine. In the single-cell labeling experiments, each entire axonal tree was reconstructed from serial sections, the length of terminal axonal arbors was estimated by stereology, and the dopaminergic phenotype was tested by double-labeling for tyrosine hydroxylase immunofluorescence. We observed two main, markedly different VTA cell morphologies: neurons with a single main axon targeting only forebrain structures (FPN cells), and neurons with multibranched axons targeting both the forebrain and the brainstem (F + BSPN cells). Dopaminergic phenotype was observed in FPN cells. Moreover, four “subtypes” could be distinguished among the FPN cells based on their projection targets: (1) “Mesocorticolimbic” FPN projecting to both neocortex and basal forebrain; (2) “Mesocortical” FPN innervating the neocortex almost exclusively; (3) “Mesolimbic” FPN projecting to the basal forebrain, accumbens and caudateputamen; and (4) “Mesostriatal” FPN targeting only the caudateputamen. While the F + BSPN cells were scattered within VTA, the mesolimbic neurons were abundant in the paranigral nucleus. The observed diversity in wiring architectures is consistent with the notion that different VTA cell subpopulations modulate the activity of specific sets of prosencephalic and brainstem structures.
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Affiliation(s)
- Ana Aransay
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid Madrid, Spain
| | - Claudia Rodríguez-López
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid Madrid, Spain
| | - María García-Amado
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid Madrid, Spain
| | - Francisco Clascá
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid Madrid, Spain
| | - Lucía Prensa
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid Madrid, Spain
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