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Wheeler DW, Banduri S, Sankararaman S, Vinay S, Ascoli GA. Unsupervised classification of brain-wide axons reveals the presubiculum neuronal projection blueprint. Nat Commun 2024; 15:1555. [PMID: 38378961 PMCID: PMC10879163 DOI: 10.1038/s41467-024-45741-x] [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] [Accepted: 02/01/2024] [Indexed: 02/22/2024] Open
Abstract
We present a quantitative strategy to identify all projection neuron types from a given region with statistically different patterns of anatomical targeting. We first validate the technique with mouse primary motor cortex layer 6 data, yielding two clusters consistent with cortico-thalamic and intra-telencephalic neurons. We next analyze the presubiculum, a less-explored region, identifying five classes of projecting neurons with unique patterns of divergence, convergence, and specificity. We report several findings: individual classes target multiple subregions along defined functions; all hypothalamic regions are exclusively targeted by the same class also invading midbrain and agranular retrosplenial cortex; Cornu Ammonis receives input from a single class of presubicular axons also projecting to granular retrosplenial cortex; path distances from the presubiculum to the same targets differ significantly between classes, as do the path distances to distinct targets within most classes; the identified classes have highly non-uniform abundances; and presubicular somata are topographically segregated among classes. This study thus demonstrates that statistically distinct projections shed light on the functional organization of their circuit.
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Affiliation(s)
- Diek W Wheeler
- Center for Neural Informatics, Krasnow Institute for Advanced Studies and Bioengineering Department, College of Engineering & Computing, George Mason University, Fairfax, VA, USA.
| | - Shaina Banduri
- Center for Neural Informatics, Krasnow Institute for Advanced Studies and Bioengineering Department, College of Engineering & Computing, George Mason University, Fairfax, VA, USA
| | - Sruthi Sankararaman
- Center for Neural Informatics, Krasnow Institute for Advanced Studies and Bioengineering Department, College of Engineering & Computing, George Mason University, Fairfax, VA, USA
| | - Samhita Vinay
- Center for Neural Informatics, Krasnow Institute for Advanced Studies and Bioengineering Department, College of Engineering & Computing, George Mason University, Fairfax, VA, USA
| | - Giorgio A Ascoli
- Center for Neural Informatics, Krasnow Institute for Advanced Studies and Bioengineering Department, College of Engineering & Computing, George Mason University, Fairfax, VA, USA.
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2
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Gonzalo-Martín E, Alonso-Martínez C, Sepúlveda LP, Clasca F. Micropopulation mapping of the mouse parafascicular nucleus connections reveals diverse input-output motifs. Front Neuroanat 2024; 17:1305500. [PMID: 38260117 PMCID: PMC10800635 DOI: 10.3389/fnana.2023.1305500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Accepted: 11/10/2023] [Indexed: 01/24/2024] Open
Abstract
Introduction In primates, including humans, the centromedian/parafascicular (CM-Pf) complex is a key thalamic node of the basal ganglia system. Deep brain stimulation in CM-Pf has been applied for the treatment of motor disorders such as Parkinson's disease or Tourette syndrome. Rodents have become widely used models for the study of the cellular and genetic mechanisms of these and other motor disorders. However, the equivalence between the primate CM-Pf and the nucleus regarded as analogous in rodents (Parafascicular, Pf) remains unclear. Methods Here, we analyzed the neurochemical architecture and carried out a brain-wide mapping of the input-output motifs in the mouse Pf at micropopulation level using anterograde and retrograde labeling methods. Specifically, we mapped and quantified the sources of cortical and subcortical input to different Pf subregions, and mapped and compared the distribution and terminal structure of their axons. Results We found that projections to Pf arise predominantly (>75%) from the cerebral cortex, with an unusually strong (>45%) Layer 5b component, which is, in part, contralateral. The intermediate layers of the superior colliculus are the main subcortical input source to Pf. On its output side, Pf neuron axons predominantly innervate the striatum. In a sparser fashion, they innervate other basal ganglia nuclei, including the subthalamic nucleus (STN), and the cerebral cortex. Differences are evident between the lateral and medial portions of Pf, both in chemoarchitecture and in connectivity. Lateral Pf axons innervate territories of the striatum, STN and cortex involved in the sensorimotor control of different parts of the contralateral hemibody. In contrast, the mediodorsal portion of Pf innervates oculomotor-limbic territories in the above three structures. Discussion Our data thus indicate that the mouse Pf consists of several neurochemically and connectively distinct domains whose global organization bears a marked similarity to that described in the primate CM-Pf complex.
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Affiliation(s)
| | | | | | - Francisco Clasca
- Department of Anatomy and Neuroscience, Autónoma de Madrid University, Madrid, Spain
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3
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Yang H, Shan W, Fan J, Deng J, Luan G, Wang Q, Zhang Y, You H. Mapping the Neural Circuits Responding to Deep Brain Stimulation of the Anterior Nucleus of the Thalamus in the Rat Brain. Epilepsy Res 2022; 187:107027. [DOI: 10.1016/j.eplepsyres.2022.107027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 08/15/2022] [Accepted: 09/24/2022] [Indexed: 11/25/2022]
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4
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Kim S, Nam Y, Kim HS, Jung H, Jeon SG, Hong SB, Moon M. Alteration of Neural Pathways and Its Implications in Alzheimer’s Disease. Biomedicines 2022; 10:biomedicines10040845. [PMID: 35453595 PMCID: PMC9025507 DOI: 10.3390/biomedicines10040845] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/29/2022] [Accepted: 03/31/2022] [Indexed: 02/01/2023] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disease accompanied by cognitive and behavioral symptoms. These AD-related manifestations result from the alteration of neural circuitry by aggregated forms of amyloid-β (Aβ) and hyperphosphorylated tau, which are neurotoxic. From a neuroscience perspective, identifying neural circuits that integrate various inputs and outputs to determine behaviors can provide insight into the principles of behavior. Therefore, it is crucial to understand the alterations in the neural circuits associated with AD-related behavioral and psychological symptoms. Interestingly, it is well known that the alteration of neural circuitry is prominent in the brains of patients with AD. Here, we selected specific regions in the AD brain that are associated with AD-related behavioral and psychological symptoms, and reviewed studies of healthy and altered efferent pathways to the target regions. Moreover, we propose that specific neural circuits that are altered in the AD brain can be potential targets for AD treatment. Furthermore, we provide therapeutic implications for targeting neuronal circuits through various therapeutic approaches and the appropriate timing of treatment for AD.
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Affiliation(s)
- Sujin Kim
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
- Research Institute for Dementia Science, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea
| | - Yunkwon Nam
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
| | - Hyeon soo Kim
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
| | - Haram Jung
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
| | - Seong Gak Jeon
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
| | - Sang Bum Hong
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
| | - Minho Moon
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
- Research Institute for Dementia Science, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea
- Correspondence:
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5
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Kwon DH, Paek SH, Kim YB, Lee H, Cho ZH. In vivo 3D Reconstruction of the Human Pallidothalamic and Nigrothalamic Pathways With Super-Resolution 7T MR Track Density Imaging and Fiber Tractography. Front Neuroanat 2021; 15:739576. [PMID: 34776880 PMCID: PMC8579044 DOI: 10.3389/fnana.2021.739576] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 10/06/2021] [Indexed: 11/13/2022] Open
Abstract
The output network of the basal ganglia plays an important role in motor, associative, and limbic processing and is generally characterized by the pallidothalamic and nigrothalamic pathways. However, these connections in the human brain remain difficult to elucidate because of the resolution limit of current neuroimaging techniques. The present study aimed to investigate the mesoscopic nature of these connections between the thalamus, substantia nigra pars reticulata, and globus pallidus internal segment using 7 Tesla (7T) magnetic resonance imaging (MRI). In this study, track-density imaging (TDI) of the whole human brain was employed to overcome the limitations of observing the pallidothalamic and nigrothalamic tracts. Owing to the super-resolution of the TD images, the substructures of the SN, as well as the associated tracts, were identified. This study demonstrates that 7T MRI and MR tractography can be used to visualize anatomical details, as well as 3D reconstruction, of the output projections of the basal ganglia.
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Affiliation(s)
- Dae-Hyuk Kwon
- Neuroscience Convergence Center, Green Manufacturing Research Center (GMRC), Korea University, Seoul, South Korea
| | - Sun Ha Paek
- Neurosurgery, Movement Disorder Center, Seoul National University College of Medicine, Advanced Institute of Convergence Technology (AICT), Seoul National University, Seoul, South Korea
| | - Young-Bo Kim
- Department of Neurosurgery, College of Medicine, Gachon University, Incheon, South Korea
| | - Haigun Lee
- Department of Materials Science and Engineering, Korea University, Seoul, South Korea
| | - Zang-Hee Cho
- Neuroscience Convergence Center, Green Manufacturing Research Center (GMRC), Korea University, Seoul, South Korea
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6
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Phillips JM, Kambi NA, Redinbaugh MJ, Mohanta S, Saalmann YB. Disentangling the influences of multiple thalamic nuclei on prefrontal cortex and cognitive control. Neurosci Biobehav Rev 2021; 128:487-510. [PMID: 34216654 DOI: 10.1016/j.neubiorev.2021.06.042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 04/13/2021] [Accepted: 06/09/2021] [Indexed: 10/21/2022]
Abstract
The prefrontal cortex (PFC) has a complex relationship with the thalamus, involving many nuclei which occupy predominantly medial zones along its anterior-to-posterior extent. Thalamocortical neurons in most of these nuclei are modulated by the affective and cognitive signals which funnel through the basal ganglia. We review how PFC-connected thalamic nuclei likely contribute to all aspects of cognitive control: from the processing of information on internal states and goals, facilitating its interactions with mnemonic information and learned values of stimuli and actions, to their influence on high-level cognitive processes, attentional allocation and goal-directed behavior. This includes contributions to transformations such as rule-to-choice (parvocellular mediodorsal nucleus), value-to-choice (magnocellular mediodorsal nucleus), mnemonic-to-choice (anteromedial nucleus) and sensory-to-choice (medial pulvinar). Common mechanisms appear to be thalamic modulation of cortical gain and cortico-cortical functional connectivity. The anatomy also implies a unique role for medial PFC in modulating processing in thalamocortical circuits involving other orbital and lateral PFC regions. We further discuss how cortico-basal ganglia circuits may provide a mechanism through which PFC controls cortico-cortical functional connectivity.
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Affiliation(s)
- Jessica M Phillips
- Department of Psychology, University of Wisconsin-Madison, 1202 W Johnson St., Madison, WI 53706, United States.
| | - Niranjan A Kambi
- Department of Psychology, University of Wisconsin-Madison, 1202 W Johnson St., Madison, WI 53706, United States
| | - Michelle J Redinbaugh
- Department of Psychology, University of Wisconsin-Madison, 1202 W Johnson St., Madison, WI 53706, United States
| | - Sounak Mohanta
- Department of Psychology, University of Wisconsin-Madison, 1202 W Johnson St., Madison, WI 53706, United States
| | - Yuri B Saalmann
- Department of Psychology, University of Wisconsin-Madison, 1202 W Johnson St., Madison, WI 53706, United States; Wisconsin National Primate Research Center, University of Wisconsin-Madison, 1202 Capitol Ct., Madison, WI 53715, United States.
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7
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Crunelli V, Lőrincz ML, McCafferty C, Lambert RC, Leresche N, Di Giovanni G, David F. Clinical and experimental insight into pathophysiology, comorbidity and therapy of absence seizures. Brain 2020; 143:2341-2368. [PMID: 32437558 PMCID: PMC7447525 DOI: 10.1093/brain/awaa072] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 12/19/2019] [Accepted: 01/31/2020] [Indexed: 12/24/2022] Open
Abstract
Absence seizures in children and teenagers are generally considered relatively benign because of their non-convulsive nature and the large incidence of remittance in early adulthood. Recent studies, however, show that 30% of children with absence seizures are pharmaco-resistant and 60% are affected by severe neuropsychiatric comorbid conditions, including impairments in attention, cognition, memory and mood. In particular, attention deficits can be detected before the epilepsy diagnosis, may persist even when seizures are pharmacologically controlled and are aggravated by valproic acid monotherapy. New functional MRI-magnetoencephalography and functional MRI-EEG studies provide conclusive evidence that changes in blood oxygenation level-dependent signal amplitude and frequency in children with absence seizures can be detected in specific cortical networks at least 1 min before the start of a seizure, spike-wave discharges are not generalized at seizure onset and abnormal cortical network states remain during interictal periods. From a neurobiological perspective, recent electrical recordings and imaging of large neuronal ensembles with single-cell resolution in non-anaesthetized models show that, in contrast to the predominant opinion, cortical mechanisms, rather than an exclusively thalamic rhythmogenesis, are key in driving seizure ictogenesis and determining spike-wave frequency. Though synchronous ictal firing characterizes cortical and thalamic activity at the population level, individual cortico-thalamic and thalamocortical neurons are sparsely recruited to successive seizures and consecutive paroxysmal cycles within a seizure. New evidence strengthens previous findings on the essential role for basal ganglia networks in absence seizures, in particular the ictal increase in firing of substantia nigra GABAergic neurons. Thus, a key feature of thalamic ictogenesis is the powerful increase in the inhibition of thalamocortical neurons that originates at least from two sources, substantia nigra and thalamic reticular nucleus. This undoubtedly provides a major contribution to the ictal decrease in total firing and the ictal increase of T-type calcium channel-mediated burst firing of thalamocortical neurons, though the latter is not essential for seizure expression. Moreover, in some children and animal models with absence seizures, the ictal increase in thalamic inhibition is enhanced by the loss-of-function of the astrocytic GABA transporter GAT-1 that does not necessarily derive from a mutation in its gene. Together, these novel clinical and experimental findings bring about paradigm-shifting views of our understanding of absence seizures and demand careful choice of initial monotherapy and continuous neuropsychiatric evaluation of affected children. These issues are discussed here to focus future clinical and experimental research and help to identify novel therapeutic targets for treating both absence seizures and their comorbidities.
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Affiliation(s)
- Vincenzo Crunelli
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta.,Neuroscience Division, School of Bioscience, Cardiff University, Museum Avenue, Cardiff, UK
| | - Magor L Lőrincz
- Neuroscience Division, School of Bioscience, Cardiff University, Museum Avenue, Cardiff, UK.,Department of Physiology, Faculty of Medicine, University of Szeged, Szeged, Hungary.,Department of Physiology, Anatomy and Neuroscience, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Cian McCafferty
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Régis C Lambert
- Sorbonne Université, CNRS, INSERM, Neuroscience Paris Seine and Institut de Biologie Paris Seine (NPS - IBPS), Paris, France
| | - Nathalie Leresche
- Sorbonne Université, CNRS, INSERM, Neuroscience Paris Seine and Institut de Biologie Paris Seine (NPS - IBPS), Paris, France
| | - Giuseppe Di Giovanni
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta.,Neuroscience Division, School of Bioscience, Cardiff University, Museum Avenue, Cardiff, UK
| | - François David
- Cerebral dynamics, learning and plasticity, Integrative Neuroscience and Cognition Center - UMR 8002, Paris, France
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8
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Rizzi G, Tan KR. Synergistic Nigral Output Pathways Shape Movement. Cell Rep 2020; 27:2184-2198.e4. [PMID: 31091455 DOI: 10.1016/j.celrep.2019.04.068] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 03/15/2019] [Accepted: 04/15/2019] [Indexed: 01/26/2023] Open
Abstract
Locomotion relies on the activity of basal ganglia networks, where, as the output, the substantia nigra pars reticulata (SNr) integrates incoming signals and relays them to downstream areas. The cellular and circuit substrates of such a complex function remain unclear. We hypothesized that the SNr controls different aspects of locomotion through coordinated cell-type-specific sub-circuits. Using anatomical mapping, single-cell qPCR, and electrophysiological techniques, we identified two SNr sub-populations: the centromedial-thalamo projectors (CMps) and the SN compacta projectors (SNcps), which are genetically targeted based on vesicular transporter for gamma-aminobutyric acid (VGAT) or parvalbumin (PV) expression, respectively. Optogenetic manipulation of these two sub-types across a series of motor tests provided evidence that they govern different aspects of motor behavior. While CMp activity supports the continuity of motor patterns, SNcp modulates the immediate motor drive behind them. Collectively, our data suggest that at least two different sub-circuits arise from the SNr, engage different behavioral motor components, and collaborate to produce correct locomotion.
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Affiliation(s)
- Giorgio Rizzi
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | - Kelly R Tan
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland.
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9
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Unbalanced Inhibitory/Excitatory Responses in the Substantia Nigra Pars Reticulata Underlie Cannabinoid-Related Slowness of Movements. J Neurosci 2020; 40:5769-5784. [PMID: 32532888 DOI: 10.1523/jneurosci.0045-20.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 06/02/2020] [Accepted: 06/04/2020] [Indexed: 11/21/2022] Open
Abstract
The substantia nigra pars reticulata (SNr), where the basal ganglia (BG) direct and indirect pathways converge, contains among the highest expression of cannabinoid receptor type 1 (CB1r) in the brain. Hence, SNr is an ideal locus to study pathway interactions and cannabinergic modulations. The objective of this study was to characterize the effects of systemic injections of the CB1r agonist (CP55940) on the balanced activity of the direct/indirect pathways in the SNr and its associated behaviors. To this aim, we recorded somatosensory and pathway-specific representations in the spiking activity of the SNr of male rats under CP55940. CB1r activation mainly decreased the inhibitory, potentially direct pathway component while sparing the excitatory, potentially indirect pathway component of somatosensory responses. As a result, cutaneous stimulation produced unbalanced responses favoring increased SNr firing rates, suggesting a potential locus for cannabinergic motor-related effects. To test this hypothesis, we implemented an ad hoc behavioral protocol for rats in which systemic administration of CP55940 produced kinematic impairments that were completely reverted by nigral injections of the CB1r antagonist (AM251). Our data suggest that cannabinoid-related motor effects are associated with unbalanced direct/indirect pathway activations that may be reverted by CB1r manipulation at the SNr.SIGNIFICANCE STATEMENT The cannabinergic system has been the target of multiple studies to master its potential use as a therapeutic agent. However, significant advances have been precluded by the lack of mechanistic explanations for the variety of its desirable/undesirable effects. Here, we have combined electrophysiological recordings, pharmacological and optogenetic manipulations, and an ad hoc behavioral protocol to understand how basal ganglia (BG) is affected by cannabinoids. We found that cannabinoids principally affect inhibitory inputs, potentially from the direct pathway, resulting in unbalanced responses in the substantia nigra pars reticulata (SNr) and suggesting a mechanism for the cannabinoid-related slowness of movements. This possibility was confirmed by behavioral experiments in which cannabinoid-related slowness of purposeful movements was reverted by cannabinoid receptor type 1 (CB1r) manipulations directly into the SNr.
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10
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Oishi K, Mori S, Troncoso JC, Lenz FA. Mapping tracts in the human subthalamic area by 11.7T ex vivo diffusion tensor imaging. Brain Struct Funct 2020; 225:1293-1312. [PMID: 32303844 DOI: 10.1007/s00429-020-02066-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 04/03/2020] [Indexed: 02/07/2023]
Abstract
The cortico-basal ganglia-thalamo-cortical feedback loops that consist of distinct white matter pathways are important for understanding in vivo imaging studies of functional and anatomical connectivity, and for localizing subthalamic white matter structures in surgical approaches for movement disorders, such as Parkinson's disease. Connectomic analysis in animals has identified fiber connections between the basal ganglia and thalamus, which pass through the fields of Forel, where other fiber pathways related to motor, sensory, and cognitive functions co-exist. We now report these pathways in the human brain on ex vivo mesoscopic (250 μm) diffusion tensor imaging and on tractography. The locations of the tracts were identified relative to the adjacent gray matter structures, such as the internal and external segments of the globus pallidus; the zona incerta; the subthalamic nucleus; the substantia nigra pars reticulata and compacta; and the thalamus. The connectome atlas of the human subthalamic region may serve as a resource for imaging studies and for neurosurgical planning.
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Affiliation(s)
- Kenichi Oishi
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 208 Traylor Building, 720 Rutland Ave., Baltimore, MD, 21205, USA.
| | - Susumu Mori
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 208 Traylor Building, 720 Rutland Ave., Baltimore, MD, 21205, USA.,Kennedy Krieger Institute, Baltimore, MD, USA
| | - Juan C Troncoso
- Division of Neuropathology, Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Frederick A Lenz
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Meyer 8181 Neurosurgery, 600 North Wolfe Street, Baltimore, MD, 21287, USA.
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11
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Yasuda M, Hikosaka O. Medial thalamus in the territory of oculomotor basal ganglia represents stable object value. Eur J Neurosci 2018; 49:672-686. [PMID: 30307646 PMCID: PMC6426671 DOI: 10.1111/ejn.14202] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 09/11/2018] [Accepted: 10/04/2018] [Indexed: 12/15/2022]
Abstract
Many visual objects are attached with values which were created by our long rewarding history. Such stable object values attract gaze. We previously found that the output pathway of basal ganglia from caudal‐dorsal‐lateral portion of substantia nigra pars reticulata (cdlSNr) to superior colliculus (SC) carries robust stable value signal to execute the automatic choice of valuable objects. An important question here is whether stable value signal in basal ganglia can influence on other inner processing such as perception, attention, emotion, or arousal than motor execution. The key brain circuit is another output path of basal ganglia: the pathway from SNr to temporal and frontal lobes through thalamus. To examine the existence of stable value signal in this pathway, we explored thalamus in a wide range. We found that many neurons in the medial thalamus represented stable value. Histological examination showed that the recorded sites of those neurons included ventral anterior nucleus, pars magnocellularis (VAmc) which is the main target of nigrothalamic projection. Consistent with the SNr GABArgic projection, the latency of value signal in the medial thalamus was later than cdlSNr, and the sign of value coding in the medial thalamus was opposite to cdlSNr. As is the case with cdlSNr neurons, the medial thalamus neurons showed no sensitivity to frequently updated value (flexible value). These results suggest that the pathway from cdlSNr to the medial thalamus influences on various aspects of cognitive processing by propagating stable value signal to the wide cortical area.
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Affiliation(s)
- Masaharu Yasuda
- Laboratory of Sensorimotor Research, National Eye Institute, National Institutes of Health, Bethesda, MD, USA.,Department of Physiology, Kansai Medical University, 2-5-1 Shin-machi, Hirakata City, Osaka, 573-0101, Japan
| | - Okihide Hikosaka
- Laboratory of Sensorimotor Research, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
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12
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Neudorfer C, Maarouf M. Neuroanatomical background and functional considerations for stereotactic interventions in the H fields of Forel. Brain Struct Funct 2017; 223:17-30. [DOI: 10.1007/s00429-017-1570-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 11/13/2017] [Indexed: 11/29/2022]
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13
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Greene JG. Causes and consequences of degeneration of the dorsal motor nucleus of the vagus nerve in Parkinson's disease. Antioxid Redox Signal 2014; 21:649-67. [PMID: 24597973 DOI: 10.1089/ars.2014.5859] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
SIGNIFICANCE Parkinson's disease (PD) is no longer considered merely a movement disorder caused by degeneration of dopamine neurons in the midbrain. It is now recognized as a widespread neuropathological syndrome accompanied by a variety of motor and nonmotor clinical symptoms. As such, any hypothesis concerning PD pathogenesis and pathophysiology must account for the entire spectrum of disease and not solely focus on the dopamine system. RECENT ADVANCES Based on its anatomy and the intrinsic properties of its neurons, the dorsal motor nucleus of the vagus nerve (DMV) is uniquely vulnerable to damage from PD. Fibers in the vagus nerve course throughout the gastrointestinal (GI) tract to and from the brainstem forming a close link between the peripheral and central nervous systems and a point of proximal contact between the environment and areas where PD pathology is believed to start. In addition, DMV neurons are under high levels of oxidative stress due to their high level of α-synuclein expression, fragile axons, and specific neuronal physiology. Moreover, several consequences of DMV damage, namely, GI dysfunction and unrestrained inflammation, may propagate a vicious cycle of injury affecting vulnerable brain regions. CRITICAL ISSUES Current evidence to suggest the vagal system plays a pivotal role in PD pathogenesis is circumstantial, but given the current state of the field, the time is ripe to obtain direct experimental evidence to better delineate it. FUTURE DIRECTIONS Better understanding of the DMV and vagus nerve may provide insight into PD pathogenesis and a neural highway with direct brain access that could be harnessed for novel therapeutic interventions.
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Affiliation(s)
- James G Greene
- Department of Neurology, Emory University , Atlanta, Georgia
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14
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The substantia nigra conveys target-dependent excitatory and inhibitory outputs from the basal ganglia to the thalamus. J Neurosci 2014; 34:8032-42. [PMID: 24899724 DOI: 10.1523/jneurosci.0236-14.2014] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The basal ganglia (BG), which influence cortical activity via the thalamus, play a major role in motor activity, learning and memory, sensory processing, and many aspects of behavior. The substantia nigra (SN) consists of GABAergic neurons of the pars reticulata that inhibit thalamic neurons and provide the primary output of the BG, and dopaminergic neurons of the pars compacta that modulate thalamic excitability. Little is known about the functional properties of the SN→thalamus synapses, and anatomical characterization has been controversial. Here we use a combination of anatomical, electrophysiological, genetic, and optogenetic approaches to re-examine these synaptic connections in mice. We find that neurons in the SN inhibit neurons in the ventroposterolateral nucleus of the thalamus via GABAergic synapses, excite neurons in the thalamic nucleus reticularis, and both excite and inhibit neurons within the posterior nucleus group. Glutamatergic SN neurons express the vesicular glutamate receptor transporter vGluT2 and receive inhibitory synapses from striatal neurons, and many also express tyrosine hydroxylase, a marker of dopaminergic neurons. Thus, in addition to providing inhibitory outputs, which is consistent with the canonical circuit, the SN provides glutamatergic outputs that differentially target thalamic nuclei. This suggests that an increase in the activity of glutamatergic neurons in the SN allows the BG to directly excite neurons in specific thalamic nuclei. Elucidating an excitatory connection between the BG and the thalamus provides new insights into how the BG regulate thalamic activity, and has important implications for understanding BG function in health and disease.
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15
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Barbas H, García-Cabezas MÁ, Zikopoulos B. Frontal-thalamic circuits associated with language. BRAIN AND LANGUAGE 2013; 126:49-61. [PMID: 23211411 PMCID: PMC3615046 DOI: 10.1016/j.bandl.2012.10.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2011] [Revised: 09/20/2012] [Accepted: 10/18/2012] [Indexed: 05/20/2023]
Abstract
Thalamic nuclei associated with language including the ventral lateral, ventral anterior, intralaminar and mediodorsal form a hub that uniquely receives the output of the basal ganglia and cerebellum, and is connected with frontal (premotor and prefrontal) cortices through two parallel circuits: a thalamic pathway targets the middle frontal cortical layers focally, and the other innervates widely cortical layer 1, poised to recruit other cortices and thalamic nuclei for complex cognitive operations. Return frontal pathways to the thalamus originate from cortical layers 6 and 5. Information through this integrated thalamo-cortical system is gated by the inhibitory thalamic reticular nucleus and modulated by dopamine, representing a specialization in primates. The intricate dialogue of distinct thalamic nuclei with the basal ganglia, cerebellum, and specific dorsolateral prefrontal and premotor cortices associated with language, suggests synergistic roles in the complex but seemingly effortless sequential transformation of cognitive operations for speech production in humans.
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Affiliation(s)
- Helen Barbas
- Neural Systems Laboratory, Boston University, Boston, MA 02215, USA.
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16
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Sutton AC, Yu W, Calos ME, Smith AB, Ramirez-Zamora A, Molho ES, Pilitsis JG, Brotchie JM, Shin DS. Deep brain stimulation of the substantia nigra pars reticulata improves forelimb akinesia in the hemiparkinsonian rat. J Neurophysiol 2012; 109:363-74. [PMID: 23076106 DOI: 10.1152/jn.00311.2012] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Deep brain stimulation (DBS) employing high-frequency stimulation (HFS) is commonly used in the globus pallidus interna (GPi) and the subthalamic nucleus (STN) for treating motor symptoms of patients with Parkinson's disease (PD). Although DBS improves motor function in most PD patients, disease progression and stimulation-induced nonmotor complications limit DBS in these areas. In this study, we assessed whether stimulation of the substantia nigra pars reticulata (SNr) improved motor function. Hemiparkinsonian rats predominantly touched with their unimpaired forepaw >90% of the time in the stepping and limb-use asymmetry tests. After SNr-HFS (150 Hz), rats touched equally with both forepaws, similar to naive and sham-lesioned rats. In vivo, SNr-HFS decreased beta oscillations (12-30 Hz) in the SNr of freely moving hemiparkinsonian rats and decreased SNr neuronal spiking activity from 28 ± 1.9 Hz before stimulation to 0.8 ± 1.9 Hz during DBS in anesthetized animals; also, neuronal spiking activity increased from 7 ± 1.6 to 18 ± 1.6 Hz in the ventromedial portion of the thalamus (VM), the primary SNr efferent. In addition, HFS of the SNr in brain slices from normal and reserpine-treated rat pups resulted in a depolarization block of SNr neuronal activity. We demonstrate improvement of forelimb akinesia with SNr-HFS and suggest that this motor effect may have resulted from the attenuation of SNr neuronal activity, decreased SNr beta oscillations, and increased activity of VM thalamic neurons, suggesting that the SNr may be a plausible DBS target for treating motor symptoms of DBS.
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Affiliation(s)
- Alexander C Sutton
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, NY 12208, USA
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17
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Kusnoor SV, Bubser M, Deutch AY. The effects of nigrostriatal dopamine depletion on the thalamic parafascicular nucleus. Brain Res 2012; 1446:46-55. [PMID: 22353754 DOI: 10.1016/j.brainres.2012.01.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 12/22/2011] [Accepted: 01/18/2012] [Indexed: 10/14/2022]
Abstract
Neuronal loss in Parkinson's disease (PD) is seen in a number of brain regions in addition to the substantia nigra (SN). Among these is the thalamic parafascicular nucleus (PF), which sends glutamatergic projections to the striatum and receives GABAergic inputs from the SN. Recent data suggest that lesions of nigrostriatal dopamine axons cause a loss of PF neurons, which has been interpreted to suggest that the PF cell loss seen in PD is secondary to dopamine denervation. However, the extent of a PF dopamine innervation in the rat is unclear, and it is possible that PF cell loss in parkinsonism is independent of nigrostriatal dopamine degeneration. We characterized the dopamine innervation of the PF in the rat and determined if 6-hydroxydopamine SN lesions cause PF neuron degeneration. Dual-label immunohistochemistry revealed that almost all tyrosine hydroxylase-immunoreactive (TH-ir) axons in the PF also expressed dopamine-beta-hydroxylase and were therefore noradrenergic or adrenergic. Moreover, an antibody directed against dopamine revealed only very rare PF dopaminergic axons. Retrograde-tract tracing-immunohistochemistry did not uncover an innervation of the PF from midbrain dopamine neurons. Nigrostriatal dopamine neuron lesions did not elicit degeneration of PF cells, as reflected by a lack of FluoroJade C staining. Similarly, neither unilateral 6-OHDA lesions of nigrostriatal axons nor the dorsal noradrenergic bundle decreased the number of PF neurons or the number of PF neurons retrogradely-labeled from the striatum. These data suggest that the loss of thalamostriatal PF neurons in Parkinson's Disease is a primary event rather than secondary to nigrostriatal dopamine degeneration.
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Affiliation(s)
- Sheila V Kusnoor
- Department of Psychiatry, Vanderbilt University Medical Center, Nashville, TN 37212, USA
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18
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Solari SVH, Stoner R. Cognitive consilience: primate non-primary neuroanatomical circuits underlying cognition. Front Neuroanat 2011; 5:65. [PMID: 22194717 PMCID: PMC3243081 DOI: 10.3389/fnana.2011.00065] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 12/01/2011] [Indexed: 11/16/2022] Open
Abstract
Interactions between the cerebral cortex, thalamus, and basal ganglia form the basis of cognitive information processing in the mammalian brain. Understanding the principles of neuroanatomical organization in these structures is critical to understanding the functions they perform and ultimately how the human brain works. We have manually distilled and synthesized hundreds of primate neuroanatomy facts into a single interactive visualization. The resulting picture represents the fundamental neuroanatomical blueprint upon which cognitive functions must be implemented. Within this framework we hypothesize and detail 7 functional circuits corresponding to psychological perspectives on the brain: consolidated long-term declarative memory, short-term declarative memory, working memory/information processing, behavioral memory selection, behavioral memory output, cognitive control, and cortical information flow regulation. Each circuit is described in terms of distinguishable neuronal groups including the cerebral isocortex (9 pyramidal neuronal groups), parahippocampal gyrus and hippocampus, thalamus (4 neuronal groups), basal ganglia (7 neuronal groups), metencephalon, basal forebrain, and other subcortical nuclei. We focus on neuroanatomy related to primate non-primary cortical systems to elucidate the basis underlying the distinct homotypical cognitive architecture. To display the breadth of this review, we introduce a novel method of integrating and presenting data in multiple independent visualizations: an interactive website (http://www.frontiersin.org/files/cognitiveconsilience/index.html) and standalone iPhone and iPad applications. With these tools we present a unique, annotated view of neuroanatomical consilience (integration of knowledge).
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Zhou FM, Lee CR. Intrinsic and integrative properties of substantia nigra pars reticulata neurons. Neuroscience 2011; 198:69-94. [PMID: 21839148 PMCID: PMC3221915 DOI: 10.1016/j.neuroscience.2011.07.061] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 07/07/2011] [Accepted: 07/14/2011] [Indexed: 11/27/2022]
Abstract
The GABA projection neurons of the substantia nigra pars reticulata (SNr) are output neurons for the basal ganglia and thus critical for movement control. Their most striking neurophysiological feature is sustained, spontaneous high frequency spike firing. A fundamental question is: what are the key ion channels supporting the remarkable firing capability in these neurons? Recent studies indicate that these neurons express tonically active type 3 transient receptor potential (TRPC3) channels that conduct a Na-dependent inward current even at hyperpolarized membrane potentials. When the membrane potential reaches -60 mV, a voltage-gated persistent sodium current (I(NaP)) starts to activate, further depolarizing the membrane potential. At or slightly below -50 mV, the large transient voltage-activated sodium current (I(NaT)) starts to activate and eventually triggers the rapid rising phase of action potentials. SNr GABA neurons have a higher density of I(NaT), contributing to the faster rise and larger amplitude of action potentials, compared with the slow-spiking dopamine neurons. I(NaT) also recovers from inactivation more quickly in SNr GABA neurons than in nigral dopamine neurons. In SNr GABA neurons, the rising phase of the action potential triggers the activation of high-threshold, inactivation-resistant Kv3-like channels that can rapidly repolarize the membrane. These intrinsic ion channels provide SNr GABA neurons with the ability to fire spontaneous and sustained high frequency spikes. Additionally, robust GABA inputs from direct pathway medium spiny neurons in the striatum and GABA neurons in the globus pallidus may inhibit and silence SNr GABA neurons, whereas glutamate synaptic input from the subthalamic nucleus may induce burst firing in SNr GABA neurons. Thus, afferent GABA and glutamate synaptic inputs sculpt the tonic high frequency firing of SNr GABA neurons and the consequent inhibition of their targets into an integrated motor control signal that is further fine-tuned by neuromodulators including dopamine, serotonin, endocannabinoids, and H₂O₂.
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Affiliation(s)
- F-M Zhou
- Department of Pharmacology, University of Tennessee College of Medicine, Memphis, TN 38163, USA.
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20
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Gulcebi MI, Ketenci S, Linke R, Hacıoğlu H, Yanalı H, Veliskova J, Moshé SL, Onat F, Çavdar S. Topographical connections of the substantia nigra pars reticulata to higher-order thalamic nuclei in the rat. Brain Res Bull 2011; 87:312-8. [PMID: 22108631 DOI: 10.1016/j.brainresbull.2011.11.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 11/04/2011] [Accepted: 11/08/2011] [Indexed: 11/27/2022]
Abstract
The substantia nigra pars reticulata (SNR) is the ventral subdivision of the substantia nigra and contains mostly GABAergic neurons. The present study explores whether the SNR relates to all dorsal thalamic nuclei equally or just to a particular group of nuclei, such as first or higher-order nuclei. Injections of biotinylated dextran amine (BDA) were made into the SNR of 10 male adult rats. The distribution of anterogradely labelled axon terminals in the thalamic nuclei was documented. The projections of the SNR to the thalamic nuclei were exclusively to some motor higher-order, but not to first-order thalamic relays. There were bilateral projections to the ventromedial (VM), parafascicular (PF), centromedian (CM) and paracentral (PC) nuclei and unilateral projections to the centrolateral (CL), mediodorsal (MD) and thalamic reticular nucleus (Rt). Labelled axon terminals in the thalamic nuclei ranged from numerous to sparse in VM, PF, CM, CL, PC, MD and Rt. Further, injections into the SNR along its rostral-caudal axis showed specific topographical connections with the thalamic nuclei. The rostral SNR injections showed labelled axon terminals of VM, PF, CL, PC, CM, MD and Rt. Caudal SNR injections showed labelling of VM, PF, PC, CM and MD. All injections showed labelled axons and terminals in the zona incerta. The nigrothalamic GABAergic neurons can be regarded as an important system for the regulation of motor activities. The SNR is in a position to influence large areas of the neocortex by modulating some of the motor higher-order thalamic nuclei directly or indirectly via Rt.
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21
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Abstract
The substantia nigra pars reticulata (SNr) is a key basal ganglia output nucleus critical for movement control. A hallmark of the SNr gamma-aminobutyric acid (GABA)-containing projection neurons is their depolarized membrane potential, accompanied by rapid spontaneous spikes. Parkinsonian movement disorders are often associated with abnormalities in SNr GABA neuron firing intensity and/or pattern. A fundamental question is the molecular identity of the ion channels that drive these neurons to a depolarized membrane potential. Recent data show that SNr GABA projection neurons selectively express type 3 canonical transient receptor potential (TRPC3) channels. Such channels are tonically active and mediate an inward, Na(+)-dependent current, leading to a substantial depolarization and ensuring appropriate firing intensity and pattern in SNr GABA projection neurons. Equally important, TRPC3 channels in SNr GABA neurons are up-regulated by dopamine (DA) released from neighboring nigral DA neuron dendrites. Co-activation of D1 and D5 DA receptors leads to a TRPC3 channel-mediated inward current and increased firing in SNr GABA neurons, whereas D1-like receptor blockade reduces SNr GABA neuron firing frequency and increases their firing irregularity. TRPC3 channels serve as the effector channels mediating an ultra-short SNc-->SNr DA pathway that regulates the firing intensity and pattern of the basal ganglia output neurons.
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Affiliation(s)
- Fu-Ming Zhou
- Department of Pharmacology, University of Tennessee College of Medicine, Memphis TN 38163, USA.
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22
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Tanibuchi I, Kitano H, Jinnai K. Substantia Nigra Output to Prefrontal Cortex Via Thalamus in Monkeys. I. Electrophysiological Identification of Thalamic Relay Neurons. J Neurophysiol 2009; 102:2933-45. [DOI: 10.1152/jn.91287.2008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A few studies have been performed in primate basal ganglia–thalamo–prefrontal pathways. Nevertheless, their electrophysiological properties and anatomical arrangements remain obscure. This study examined them in nigro-thalamo-cortical pathways from the substantia nigra pars reticulata (SNr) to the frontal cortex (FRC) via the mediodorsal (MD) and ventral anterior (VA) thalamus in monkeys. First, single thalamocortical neurons with SNr input were identified by antidromic responses to FRC stimulation and by inhibitory orthodromic responses with short latencies (<5 ms) to SNr stimulation. Second, single nigrothalamic neurons were found by antidromic responses to stimulation of the portions of the MD and VA where the thalamocortical neurons were recorded. The inhibitory orthodromic responses in the thalamocortical neurons were considered to be monosynaptically induced by nigral stimulation because the latency distribution of the orthodromic responses in the thalamocortical neurons was similar to that of the antidromic responses in the nigrothalamic neurons. Almost all relay neurons in the rostrolateral MD received inhibitory afferents from the caudolateral SNr and projected to the prefrontal area ventral to the principal sulcus, which constituted the densest nigro-thalamo-cortical projections. Meanwhile, neurons in the VA received inhibitory signals from the whole rostrocaudal extent of the SNr and projected to wide regions of the FRC; neurons in its pars magnocellularis mostly projected to different prefrontal areas, while those in its pars parvocellularis projected to motor areas. This report substantiated the topography of thalamocortical neurons monosynaptically receiving inhibitory SNr input and projecting to the FRC in the primate MD and VA at the single-neuron level.
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Affiliation(s)
| | - Hiroyuki Kitano
- Departments of Physiology and
- Neurosurgery, Shiga University of Medical Science, Ohtsu, Japan
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23
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Benedetti F, Lanotte M, Colloca L, Ducati A, Zibetti M, Lopiano L. Electrophysiological properties of thalamic, subthalamic and nigral neurons during the anti-parkinsonian placebo response. J Physiol 2009; 587:3869-83. [PMID: 19546163 DOI: 10.1113/jphysiol.2009.169425] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Placebo administration to Parkinson patients is known to induce dopamine release in the striatum and to affect the activity of subthalamic nucleus (STN) neurons. By using intraoperative single-neuron recording techniques in awake patients, here we extend our previous study on STN recording, and characterize part of the neuronal circuit which is affected by placebos. In those patients who showed a clinical placebo response, there was a decrease in firing rate in STN neurons that was associated with a decrease in the substantia nigra pars reticulata (SNr) and an increase in the ventral anterior (VA) and anterior ventral lateral (VLa) thalamus. These data show that placebo decreases STN and SNr activity whereas it increases VA/VLa activity. By contrast, placebo non-responders showed either a lack of changes in this circuit or partial changes in the STN only. Thus, changes in activity in the whole basal ganglia-VA/VLa circuit appear to be important in order to observe a clinical placebo improvement, although the involvement of other circuits, such as the direct pathway bypassing the STN, cannot be ruled out. The circuit we describe in the present study is likely to be a part of a more complex circuitry, including the striatum and the internal globus pallidus (GPi), that is modified by placebo administration. These findings indicate that a placebo treatment, which is basically characterized by verbal suggestions of benefit, can reverse the malfunction of a complex neuronal circuit, although these placebo-associated neuronal changes are short-lasting and occur only in some patients but not in others.
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Affiliation(s)
- Fabrizio Benedetti
- Department of Neuroscience, University of Turin Medical School, Turin, Italy.
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24
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Schmahmann JD, Pandya DN. Disconnection syndromes of basal ganglia, thalamus, and cerebrocerebellar systems. Cortex 2008; 44:1037-66. [PMID: 18614161 DOI: 10.1016/j.cortex.2008.04.004] [Citation(s) in RCA: 188] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2008] [Revised: 04/13/2008] [Accepted: 04/14/2008] [Indexed: 10/22/2022]
Abstract
Disconnection syndromes were originally conceptualized as a disruption of communication between different cerebral cortical areas. Two developments mandate a re-evaluation of this notion. First, we present a synopsis of our anatomical studies in monkey elucidating principles of organization of cerebral cortex. Efferent fibers emanate from every cortical area, and are directed with topographic precision via association fibers to ipsilateral cortical areas, commissural fibers to contralateral cerebral regions, striatal fibers to basal ganglia, and projection subcortical bundles to thalamus, brainstem and/or pontocerebellar system. We note that cortical areas can be defined by their patterns of subcortical and cortical connections. Second, we consider motor, cognitive and neuropsychiatric disorders in patients with lesions restricted to basal ganglia, thalamus, or cerebellum, and recognize that these lesions mimic deficits resulting from cortical lesions, with qualitative differences between the manifestations of lesions in functionally related areas of cortical and subcortical nodes. We consider these findings on the basis of anatomical observations from tract tracing studies in monkey, viewing them as disconnection syndromes reflecting loss of the contribution of subcortical nodes to the distributed neural circuits. We introduce a new theoretical framework for the distributed neural circuits, based on general, and specific, principles of anatomical organization, and on the architecture of the nodes that comprise these systems. We propose that neural architecture determines function, i.e., each architectonically distinct cortical and subcortical area contributes a unique transform, or computation, to information processing; anatomically precise and segregated connections between nodes define behavior; and association fiber tracts that link cerebral cortical areas with each other enable the cross-modal integration required for evolved complex behaviors. This model enables the formulation and testing of future hypotheses in investigations using evolving magnetic resonance imaging techniques in humans, and in clinical studies in patients with cortical and subcortical lesions.
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Affiliation(s)
- Jeremy D Schmahmann
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
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25
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Gallay MN, Jeanmonod D, Liu J, Morel A. Human pallidothalamic and cerebellothalamic tracts: anatomical basis for functional stereotactic neurosurgery. Brain Struct Funct 2008; 212:443-63. [PMID: 18193279 PMCID: PMC2494572 DOI: 10.1007/s00429-007-0170-0] [Citation(s) in RCA: 164] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Accepted: 12/20/2007] [Indexed: 11/26/2022]
Abstract
Anatomical knowledge of the structures to be targeted and of the circuitry involved is crucial in stereotactic functional neurosurgery. The present study was undertaken in the context of surgical treatment of motor disorders such as essential tremor (ET) and Parkinson's disease (PD) to precisely determine the course and three-dimensional stereotactic localisation of the cerebellothalamic and pallidothalamic tracts in the human brain. The course of the fibre tracts to the thalamus was traced in the subthalamic region using multiple staining procedures and their entrance into the thalamus determined according to our atlas of the human thalamus and basal ganglia [Morel (2007) Stereotactic atlas of the human thalamus and basal ganglia. Informa Healthcare Inc., New York]. Stereotactic three-dimensional coordinates were determined by sectioning thalamic and basal ganglia blocks parallel to stereotactic planes and, in two cases, by correlation with magnetic resonance images (MRI) from the same brains prior to sectioning. The major contributions of this study are to provide: (1) evidence that the bulks of the cerebellothalamic and pallidothalamic tracts are clearly separated up to their thalamic entrance, (2) stereotactic maps of the two tracts in the subthalamic region, (3) the possibility to discriminate between different subthalamic fibre tracts on the basis of immunohistochemical stainings, (4) correlations of histologically identified fibre tracts with high-resolution MRI, and (5) evaluation of the interindividual variability of the fibre systems in the subthalamic region. This study should provide an important basis for accurate stereotactic neurosurgical targeting of the subthalamic region in motor disorders such as PD and ET.
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Affiliation(s)
- Marc N. Gallay
- Laboratory for Functional Neurosurgery, Neurosurgery Clinic, University Hospital Zürich, Sternwartstrasse 6, 8091 Zurich, Switzerland
| | - Daniel Jeanmonod
- Laboratory for Functional Neurosurgery, Neurosurgery Clinic, University Hospital Zürich, Sternwartstrasse 6, 8091 Zurich, Switzerland
| | - Jian Liu
- Laboratory for Functional Neurosurgery, Neurosurgery Clinic, University Hospital Zürich, Sternwartstrasse 6, 8091 Zurich, Switzerland
- Present Address: Department of Physiology and Pathophysiology, School of Medicine, Xi’an Jiaotong University, 710061 Xian
, People’s Republic of China
| | - Anne Morel
- Laboratory for Functional Neurosurgery, Neurosurgery Clinic, University Hospital Zürich, Sternwartstrasse 6, 8091 Zurich, Switzerland
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26
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Mallet L, Schüpbach M, N'Diaye K, Remy P, Bardinet E, Czernecki V, Welter ML, Pelissolo A, Ruberg M, Agid Y, Yelnik J. Stimulation of subterritories of the subthalamic nucleus reveals its role in the integration of the emotional and motor aspects of behavior. Proc Natl Acad Sci U S A 2007; 104:10661-6. [PMID: 17556546 PMCID: PMC1965569 DOI: 10.1073/pnas.0610849104] [Citation(s) in RCA: 338] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two parkinsonian patients who experienced transient hypomanic states when the subthalamic nucleus (STN) was stimulated during postoperative adjustment of the electrical parameters for antiparkinsonian therapy agreed to have the mood disorder reproduced, in conjunction with motor, cognitive, and behavioral evaluations and concomitant functional neuroimaging. During the experiment, STN stimulation again induced a hypomanic state concomitant with activation of cortical and thalamic regions known to process limbic and associative information. This observation suggests that the STN plays a role in the control of a complex behavior that includes emotional as well as cognitive and motor components. The localization of the four contacts of the quadripolar electrode was determined precisely with an interactive brain atlas. The results showed that (i) the hypomanic state was caused only by stimulation through one contact localized in the anteromedial STN; (ii) both this contact and the contact immediately dorsal to it improved the parkinsonian motor state; (iii) the most dorsal and ventral contacts, located at the boundaries of the STN, neither induced the behavioral disorder nor improved motor performance. Detailed analysis of these data led us to consider a model in which the three functional modalities, emotional, cognitive, and motor, are not processed in a segregated manner but can be subtly combined in the small volume of the STN. This nucleus would thus serve as a nexus that integrates the motor, cognitive, and emotional components of behavior and might consequently be an effective target for the treatment of behavioral disorders that combine emotional, cognitive, and motor impairment.
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Affiliation(s)
- Luc Mallet
- Institut National de la Santé et de la Recherche Médicale AVENIR Group, Behavior, Emotion, and Basal Ganglia, 75013 Paris, France.
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27
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Meissner W, Guigoni C, Cirilli L, Garret M, Bioulac BH, Gross CE, Bezard E, Benazzouz A. Impact of chronic subthalamic high-frequency stimulation on metabolic basal ganglia activity: a 2-deoxyglucose uptake and cytochrome oxidase mRNA study in a macaque model of Parkinson's disease. Eur J Neurosci 2007; 25:1492-500. [PMID: 17425575 DOI: 10.1111/j.1460-9568.2007.05406.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The mechanisms of action of high-frequency stimulation (HFS) of the subthalamic nucleus (STN) remain only partially understood. Hitherto, experimental studies have suggested that STN-HFS reduces the activity of STN neurons. However, some recent reports have challenged this view, showing that STN-HFS might also increase the activity of globus pallidus internalis (GPi) neurons that are under strong excitatory drive of the STN. In addition, most results emanate from studies applying acute STN-HFS, while parkinsonian patients receive chronic stimulation. Thus, the present study was designed to assess the effect of chronic (10 days) STN-HFS in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated nonhuman primate. For this purpose, 2-deoxyglucose (2-DG) uptake, a measure of global synaptic activity, was assessed in the basal ganglia and the motor thalamus after chronic unilateral STN-HFS. Cytochrome oxidase subunit 1 (COI) mRNA expression, a marker of efferent metabolic activity, was additionally assessed in the globus pallidus. Chronic STN-HFS (i) reversed abnormally decreased 2-DG uptake in the STN of parkinsonian nonhuman primates, (ii) reversed abnormally increased 2-DG accumulation in the GPi while COI mRNA expression was increased, suggesting global activation of GPi neurons, and (iii) reversed abnormally increased 2-DG uptake in the ventrolateral motor thalamus nucleus. The simultaneous decrease in 2-DG uptake and increase in COI mRNA expression are difficult to reconcile with the current model of basal ganglia function and suggest that the mechanisms by which STN-HFS exerts its clinical benefits are more complex than a simple reversal of abnormal activity in the STN and its targets.
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Affiliation(s)
- Wassilios Meissner
- CNRS UMR 5227, Université Victor Segalen, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France.
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28
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Deniau JM, Mailly P, Maurice N, Charpier S. The pars reticulata of the substantia nigra: a window to basal ganglia output. PROGRESS IN BRAIN RESEARCH 2007; 160:151-72. [PMID: 17499113 DOI: 10.1016/s0079-6123(06)60009-5] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Together with the internal segment of the globus pallidus (GP(i)), the pars reticulata of the substantia nigra (SNr) provides a main output nucleus of the basal ganglia (BG) where the final stage of information processing within this system takes place. In the last decade, progress on the anatomical organization and functional properties of BG output neurons have shed some light on the mechanisms of integration taking place in these nuclei and leading to normal and pathological BG outflow. In this review focused on the SNr, after describing how the anatomical arrangement of nigral cells and their afferents determines specific input-output registers, we examine how the basic electrophysiological properties of the cells and their interaction with synaptic inputs contribute to the spatio-temporal shaping of BG output. The reported data show that the intrinsic membrane properties of the neurons subserves a tonic discharge allowing BG to gate the transmission of information to motor and cognitive systems thereby contributing to appropriate selection of behavior.
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Affiliation(s)
- J M Deniau
- Dynamique et Physiopathologie des Réseaux Neuronaux, INSERM U667, UPMC, Collège de France, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05, France.
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Tandé D, Féger J, Hirsch EC, François C. Parafascicular nucleus projection to the extrastriatal basal ganglia in monkeys. Neuroreport 2006; 17:277-80. [PMID: 16462597 DOI: 10.1097/01.wnr.0000201508.46126.de] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We have analyzed the parafascicular thalamic projection to extrastriatal structures of the basal ganglia using anterograde and retrograde tracing in monkeys. We identified (1) retrogradely labeled neurons in the parafascicular nucleus projecting to the anteromedial, limbic part of the external and internal pallidum, the substantia nigra and the subthalamic nucleus, (2) labeled terminals scattered in all these structures after anterograde tracer injection into the medial part of the parafascicular nucleus and (3) individual parafascicular terminals that arborized rather poorly in a large portion of each basal ganglia structure. Our study provides evidence that the parafascicular nucleus, and especially its medial part, can relay emotional and motivational information back to all basal ganglia components in primates.
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Affiliation(s)
- Dominique Tandé
- INSERM U679, Neurology and Experimental Therapeutics, Pierre and Marie Curie University, Paris, France
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Abstract
Abstract
THE MOTOR THALAMUS is an important target for the treatment of tremor. It receives afferents from the cerebellum, globus pallidus internus, and substantia nigra and projects mainly to the motor cortex, premotor cortex, and supplementary motor area. Various nomenclatures have been proposed to subdivide the motor thalamus, none of which are universally accepted. Both thalamic lesions and high-frequency stimulation ameliorate tremor in diverse pathological conditions. Modern neurophysiological techniques have allowed the recording of the activity of thalamic neurons in patients with different clinical conditions. This has provided a better understanding of the functions of the motor thalamus in humans. The aim of the present article is to briefly review the major anatomic and physiological aspects of the motor thalamus as well as the electrophysiological findings described in humans undergoing surgical procedures.
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Affiliation(s)
- Clement Hamani
- Division of Neurosurgery, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada
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Bar-Gad I, Morris G, Bergman H. Information processing, dimensionality reduction and reinforcement learning in the basal ganglia. Prog Neurobiol 2003; 71:439-73. [PMID: 15013228 DOI: 10.1016/j.pneurobio.2003.12.001] [Citation(s) in RCA: 247] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2003] [Accepted: 12/01/2003] [Indexed: 11/17/2022]
Abstract
Modeling of the basal ganglia has played a major role in our understanding of this elusive group of nuclei. Models of the basal ganglia have undergone evolutionary and revolutionary changes over the last 20 years, as new research in the fields of anatomy, physiology and biochemistry of these nuclei has yielded new information. Early models dealt with a single pathway through the nuclei and focused on the nature of the processing performed within it, convergence of information versus parallel processing of information. Later, the Albin-DeLong "box-and-arrow" model characterized the inter-nuclei interaction as multiple pathways while maintaining a simplistic scalar representation of the nuclei themselves. This model made a breakthrough by providing key insights into the behavior of these nuclei in hypo- and hyper-kinetic movement disorders. The next generation of models elaborated the intra-nuclei interactions and focused on the role of the basal ganglia in action selection and sequence generation which form the most current consensus regarding basal ganglia function in both normal and pathological conditions. However, new findings challenge these models and point to a different neural network approach to information processing in the basal ganglia. Here, we take an in-depth look at the reinforcement driven dimensionality reduction (RDDR) model which postulates that the basal ganglia compress cortical information according to a reinforcement signal using optimal extraction methods. The model provides new insights and experimental predictions on the computational capacity of the basal ganglia and their role in health and disease.
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Affiliation(s)
- Izhar Bar-Gad
- Center for Neural Computation, The Hebrew University, Jerusalem, Israel.
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Abstract
BACKGROUND This article reviews the anatomy, connections, and functions of the thalamic nuclei, their vascular supply, and the clinical syndromes that result from thalamic infarction. SUMMARY OF REVIEW Thalamic nuclei are composed of 5 major functional classes: reticular and intralaminar nuclei that subserve arousal and nociception; sensory nuclei in all major domains; effector nuclei concerned with motor function and aspects of language; associative nuclei that participate in high-level cognitive functions; and limbic nuclei concerned with mood and motivation. Vascular lesions destroy these nuclei in different combinations and produce sensorimotor and behavioral syndromes depending on which nuclei are involved. Tuberothalamic territory strokes produce impairments of arousal and orientation, learning and memory, personality, and executive function; superimposition of temporally unrelated information; and emotional facial paresis. Paramedian infarcts cause decreased arousal, particularly if the lesion is bilateral, and impaired learning and memory. Autobiographical memory impairment and executive failure result from lesions in either of these vascular territories. Language deficits result from left paramedian lesions and from left tuberothalamic lesions that include the ventrolateral nucleus. Right thalamic lesions in both these vascular territories produce visual-spatial deficits, including hemispatial neglect. Inferolateral territory strokes produce contralateral hemisensory loss, hemiparesis and hemiataxia, and pain syndromes that are more common after right thalamic lesions. Posterior choroidal lesions result in visual field deficits, variable sensory loss, weakness, dystonia, tremors, and occasionally amnesia and language impairment. CONCLUSIONS These vascular syndromes reflect the reciprocal cerebral cortical-thalamic connections that have been interrupted and provide insights into the functional properties of the thalamus.
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Affiliation(s)
- Jeremy D Schmahmann
- Department of Neurology, VBK 915, Massachusetts General Hospital, Fruit St, Boston, MA 02114, USA.
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