1
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Kubo R, Yoshida T, Yamaoka K, Hashimoto K. The indirect corticopontine pathway relays perioral sensory signals to the cerebellum via the mesodiencephalic junction. iScience 2023; 26:107301. [PMID: 37539042 PMCID: PMC10393762 DOI: 10.1016/j.isci.2023.107301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 05/26/2023] [Accepted: 07/03/2023] [Indexed: 08/05/2023] Open
Abstract
In the cerebro-cerebellar loop, outputs from the cerebral cortex are thought to be transmitted via monosynaptic corticopontine gray (PG) pathways and subsequently relayed to the cerebellum. However, it is unclear whether this pathway is used constitutively for cerebro-cerebellar transduction. We examined perioral sensory pathways by unit recording from Purkinje cells in ketamine/xylazine-anesthetized mice. Infraorbital nerve stimulations enhanced simple spikes (SSs) with short and long latencies (first and second peaks), followed by SS inhibition. The second peak and SS inhibition were suppressed by muscimol (a GABAA agonist) injections into not only the PG but also the mesodiencephalic junction (MDJ). The pathway from the secondary somatosensory area (SII) to the MDJ, but not the cortico-PG pathway, transmitted the second peak signals. SS inhibition was processed in the SII and primary motor area. Thus, the indirect cortico-PG pathway, via the MDJ, is recruited for perioral sensory transduction.
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Affiliation(s)
- Reika Kubo
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Takayuki Yoshida
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Kenji Yamaoka
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Kouichi Hashimoto
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
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2
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Wu X, Sarpong GA, Zhang J, Sugihara I. Divergent topographic projection of cerebral cortical areas to overlapping cerebellar lobules through distinct regions of the pontine nuclei. Heliyon 2023; 9:e14352. [PMID: 37025843 PMCID: PMC10070096 DOI: 10.1016/j.heliyon.2023.e14352] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 02/09/2023] [Accepted: 03/01/2023] [Indexed: 03/11/2023] Open
Abstract
The massive axonal projection from the cerebrum to the cerebellum through the pontine nuclei supports the cerebrocerebellar coordination of motor and nonmotor functions. However, the cerebrum and cerebellum have distinct patterns of functional localization in their cortices. We addressed this issue by bidirectional neuronal tracing from 22 various locations of the pontine nuclei in the mouse in a comprehensive manner. Cluster analyses of the distribution patterns of labeled cortical pyramidal cells and cerebellar mossy fiber terminals classified all cases into six groups located in six different subareas of the pontine nuclei. The lateral (insular), mediorostral (cingulate and prefrontal), and caudal (visual and auditory) cortical areas of the cerebrum projected to the medial, rostral, and lateral subareas of the pontine nuclei, respectively. These pontine subareas then projected mainly to the crus I, central vermis, and paraflocculus divergently. The central (motor and somatosensory) cortical areas projected to the centrorostral, centrocaudal and caudal subareas of the pontine nuclei, which then projected mainly to the rostral and caudal lobules with a somatotopic arrangement. The results indicate a new pontine nuclei-centric view of the corticopontocerebellar projection: the generally parallel corticopontine projection to pontine nuclei subareas is relayed to the highly divergent pontocerebellar projection terminating in overlapping specific lobules of the cerebellum. Consequently, the mode of the pontine nuclei relay underlies the cerebellar functional organization.
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3
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Tocco C, Øvsthus M, Bjaalie JG, Leergaard TB, Studer M. The topography of corticopontine projections is controlled by postmitotic expression of the area-mapping gene Nr2f1. Development 2022; 149:274658. [PMID: 35262177 PMCID: PMC8959144 DOI: 10.1242/dev.200026] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 12/20/2021] [Indexed: 12/27/2022]
Abstract
Axonal projections from layer V neurons of distinct neocortical areas are topographically organized into discrete clusters within the pontine nuclei during the establishment of voluntary movements. However, the molecular determinants controlling corticopontine connectivity are insufficiently understood. Here, we show that an intrinsic cortical genetic program driven by Nr2f1 graded expression is directly implicated in the organization of corticopontine topographic mapping. Transgenic mice lacking cortical expression of Nr2f1 and exhibiting areal organization defects were used as model systems to investigate the arrangement of corticopontine projections. By combining three-dimensional digital brain atlas tools, Cre-dependent mouse lines and axonal tracing, we show that Nr2f1 expression in postmitotic neurons spatially and temporally controls somatosensory topographic projections, whereas expression in progenitor cells influences the ratio between corticopontine and corticospinal fibres passing the pontine nuclei. We conclude that cortical gradients of area-patterning genes are directly implicated in the establishment of a topographic somatotopic mapping from the cortex onto pontine nuclei. Summary: Cortical gradient expression of the area patterning gene Nr2f1 spatially and temporally controls corticopontine topographic connectivity in layer V projection neurons.
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Affiliation(s)
- Chiara Tocco
- University Côte d'Azur, CNRS, Inserm, iBV, Nice 06108, France
| | - Martin Øvsthus
- Institute of Basic Medical Sciences, University of Oslo, Oslo N-0317, Norway
| | - Jan G Bjaalie
- Institute of Basic Medical Sciences, University of Oslo, Oslo N-0317, Norway
| | - Trygve B Leergaard
- Institute of Basic Medical Sciences, University of Oslo, Oslo N-0317, Norway
| | - Michèle Studer
- University Côte d'Azur, CNRS, Inserm, iBV, Nice 06108, France
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4
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Badea A, Schmalzigaug R, Kim W, Bonner P, Ahmed U, Johnson GA, Cofer G, Foster M, Anderson RJ, Badea C, Premont RT. Microcephaly with altered cortical layering in GIT1 deficiency revealed by quantitative neuroimaging. Magn Reson Imaging 2021; 76:26-38. [PMID: 33010377 PMCID: PMC7802083 DOI: 10.1016/j.mri.2020.09.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/25/2020] [Accepted: 09/25/2020] [Indexed: 01/06/2023]
Abstract
G Protein-Coupled Receptor Kinase-Interacting Protein-1 (GIT1) regulates neuronal functions, including cell and axon migration and synapse formation and maintenance, and GIT1 knockout (KO) mice exhibit learning and memory deficits. We noted that male and female GIT1-KO mice exhibit neuroimaging phenotypes including microcephaly, and altered cortical layering, with a decrease in neuron density in cortical layer V. Micro-CT and magnetic resonance microscopy (MRM) were used to identify morphometric phenotypes for the skulls and throughout the GIT1-KO brains. High field MRM of actively-stained mouse brains from GIT1-KO and wild type (WT) controls (n = 6 per group) allowed segmenting 37 regions, based on co-registration to the Waxholm Space atlas. Overall brain size in GIT1-KO mice was ~32% smaller compared to WT controls. After correcting for brain size, several regions were significantly different in GIT1-KO mice relative to WT, including the gray matter of the ventral thalamic nuclei and the rest of the thalamus, the inferior colliculus, and pontine nuclei. GIT1-KO mice had reduced volume of white matter tracts, most notably in the anterior commissure (~26% smaller), but also in the cerebral peduncle, fornix, and spinal trigeminal tract. On the other hand, the basal ganglia appeared enlarged in GIT1-KO mice, including the globus pallidus, caudate putamen, and particularly the accumbens - supporting a possible vulnerability to addiction. Volume based morphometry based on high-resolution MRM (21.5 μm isotropic voxels) was effective in detecting overall, and local differences in brain volumes in GIT1-KO mice, including in white matter tracts. The reduced relative volume of specific brain regions suggests a critical, but not uniform, role for GIT1 in brain development, conducive to brain microcephaly, and aberrant connectivity.
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Affiliation(s)
- Alexandra Badea
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, United States of America; Department of Neurology, Duke University Medical Center, Durham, NC 27710, United States of America; Departments of Biomedical Engineering, Duke University Medical Center, Durham, NC 27710, United States of America; Brain Imaging and Analysis Center, Duke University Medical Center, Durham, NC 27710, United States of America.
| | - Robert Schmalzigaug
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, United States of America
| | - Woojoo Kim
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, United States of America
| | - Pamela Bonner
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, United States of America
| | - Umer Ahmed
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, United States of America
| | - G Allan Johnson
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, United States of America; Departments of Biomedical Engineering, Duke University Medical Center, Durham, NC 27710, United States of America
| | - Gary Cofer
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, United States of America
| | - Mark Foster
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, United States of America
| | - Robert J Anderson
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, United States of America
| | - Cristian Badea
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, United States of America; Departments of Biomedical Engineering, Duke University Medical Center, Durham, NC 27710, United States of America
| | - Richard T Premont
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, United States of America.
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5
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Chabrol FP, Blot A, Mrsic-Flogel TD. Cerebellar Contribution to Preparatory Activity in Motor Neocortex. Neuron 2019; 103:506-519.e4. [PMID: 31201123 PMCID: PMC6693889 DOI: 10.1016/j.neuron.2019.05.022] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 03/07/2019] [Accepted: 05/12/2019] [Indexed: 12/24/2022]
Abstract
In motor neocortex, preparatory activity predictive of specific movements is maintained by a positive feedback loop with the thalamus. Motor thalamus receives excitatory input from the cerebellum, which learns to generate predictive signals for motor control. The contribution of this pathway to neocortical preparatory signals remains poorly understood. Here, we show that, in a virtual reality conditioning task, cerebellar output neurons in the dentate nucleus exhibit preparatory activity similar to that in anterolateral motor cortex prior to reward acquisition. Silencing activity in dentate nucleus by photoactivating inhibitory Purkinje cells in the cerebellar cortex caused robust, short-latency suppression of preparatory activity in anterolateral motor cortex. Our results suggest that preparatory activity is controlled by a learned decrease of Purkinje cell firing in advance of reward under supervision of climbing fiber inputs signaling reward delivery. Thus, cerebellar computations exert a powerful influence on preparatory activity in motor neocortex. Similar activity in dentate nucleus (DN) and ALM cortex prior to reward acquisition Silencing DN activity selectively suppresses preparatory activity in ALM Preparatory activity likely controlled by learned decrease in Purkinje cell firing Dynamics of preparatory activity imply reward time prediction from external cues
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Affiliation(s)
- Francois P Chabrol
- Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland; Sainsbury Wellcome Center, University College London, 25 Howland Street, London W1T 4JG, UK
| | - Antonin Blot
- Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland; Sainsbury Wellcome Center, University College London, 25 Howland Street, London W1T 4JG, UK
| | - Thomas D Mrsic-Flogel
- Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland; Sainsbury Wellcome Center, University College London, 25 Howland Street, London W1T 4JG, UK.
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6
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Na J, Sugihara I, Shinoda Y. The entire trajectories of single pontocerebellar axons and their lobular and longitudinal terminal distribution patterns in multiple aldolase C-positive compartments of the rat cerebellar cortex. J Comp Neurol 2019; 527:2488-2511. [PMID: 30887503 DOI: 10.1002/cne.24685] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 03/12/2019] [Accepted: 03/12/2019] [Indexed: 11/06/2022]
Abstract
The mammalian cerebellar cortex is compartmentalized, both anatomically and histochemically, into multiple parasagittal bands. To characterize the multiple zonal patterns of pontocerebellar mossy fiber projection, single neurons in the basilar pontine nucleus (BPN) were labeled by injecting biotinylated dextran amine into the BPN, and the entire axonal trajectory of single labeled neurons (n = 25) was reconstructed in relation to aldolase C compartments of Purkinje cells in rats. Single pontocerebellar axons, after passing through the contralateral middle cerebellar peduncle, ran transversely in the deep cerebellar white matter toward and often across the midline, and on their ways, gave rise to 2-10 primary collaterals at almost right angles in specific lobules only contralaterally or bilaterally with contralateral predominance. Each primary collateral further branched in a parasagittal plane to form a strip-shaped longitudinal termination zone with rosette-type swellings clustered in aldolase C-positive compartments in a single or multiple lobules, mainly in compartment 4+//5+, 5+//6+, and 6+//7+. Axons arising from the central, rostral, and lateral part of the BPN projected with multiple branches, mainly to simple lobule, crus II and paramedian lobule, to crus I and dorsal paraflocculus, and to ventral paraflocculus and lobule IXc, respectively. The results showed the pontocerebellar projection is closely related to lobular and compartmental organization of the cerebellum. A comparison of single axon morphologies of different mossy fiber systems indicates that the projection pattern of single pontocerebellar neurons with multiple collaterals innervating different longitudinal compartments arranged in a mediolateral direction represents a general feature of mossy fiber projection.
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Affiliation(s)
- Jie Na
- Department of Systems Neurophysiology, Tokyo Medical and Dental University Graduate School of Medicine, Tokyo, Japan.,Laboratory of Brain and Cognitive Science, Shenyang Normal University, Shenyang, China
| | - Izumi Sugihara
- Department of Systems Neurophysiology, Tokyo Medical and Dental University Graduate School of Medicine, Tokyo, Japan
| | - Yoshikazu Shinoda
- Department of Systems Neurophysiology, Tokyo Medical and Dental University Graduate School of Medicine, Tokyo, Japan
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7
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Wolpaw JR. The negotiated equilibrium model of spinal cord function. J Physiol 2018; 596:3469-3491. [PMID: 29663410 PMCID: PMC6092289 DOI: 10.1113/jp275532] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 04/05/2018] [Indexed: 12/25/2022] Open
Abstract
The belief that the spinal cord is hardwired is no longer tenable. Like the rest of the CNS, the spinal cord changes during growth and ageing, when new motor behaviours are acquired, and in response to trauma and disease. This paper describes a new model of spinal cord function that reconciles its recently appreciated plasticity with its long-recognized reliability as the final common pathway for behaviour. According to this model, the substrate of each motor behaviour comprises brain and spinal plasticity: the plasticity in the brain induces and maintains the plasticity in the spinal cord. Each time a behaviour occurs, the spinal cord provides the brain with performance information that guides changes in the substrate of the behaviour. All the behaviours in the repertoire undergo this process concurrently; each repeatedly induces plasticity to preserve its key features despite the plasticity induced by other behaviours. The aggregate process is a negotiation among the behaviours: they negotiate the properties of the spinal neurons and synapses that they all use. The ongoing negotiation maintains the spinal cord in an equilibrium - a negotiated equilibrium - that serves all the behaviours. This new model of spinal cord function is supported by laboratory and clinical data, makes predictions borne out by experiment, and underlies a new approach to restoring function to people with neuromuscular disorders. Further studies are needed to test its generality, to determine whether it may apply to other CNS areas such as the cerebral cortex, and to develop its therapeutic implications.
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Affiliation(s)
- Jonathan R. Wolpaw
- National Center for Adaptive Neurotechnologies, Wadsworth CenterNYS Department of HealthAlbanyNYUSA
- Department of NeurologyStratton VA Medical CenterAlbanyNYUSA
- Department of Biomedical SciencesSchool of Public HealthSUNY AlbanyNYUSA
- Department of Neurology, Neurological InstituteColumbia UniversityNew YorkNYUSA
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8
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Kratochwil CF, Maheshwari U, Rijli FM. The Long Journey of Pontine Nuclei Neurons: From Rhombic Lip to Cortico-Ponto-Cerebellar Circuitry. Front Neural Circuits 2017; 11:33. [PMID: 28567005 PMCID: PMC5434118 DOI: 10.3389/fncir.2017.00033] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 04/28/2017] [Indexed: 01/26/2023] Open
Abstract
The pontine nuclei (PN) are the largest of the precerebellar nuclei, neuronal assemblies in the hindbrain providing principal input to the cerebellum. The PN are predominantly innervated by the cerebral cortex and project as mossy fibers to the cerebellar hemispheres. Here, we comprehensively review the development of the PN from specification to migration, nucleogenesis and circuit formation. PN neurons originate at the posterior rhombic lip and migrate tangentially crossing several rhombomere derived territories to reach their final position in ventral part of the pons. The developing PN provide a classical example of tangential neuronal migration and a study system for understanding its molecular underpinnings. We anticipate that understanding the mechanisms of PN migration and assembly will also permit a deeper understanding of the molecular and cellular basis of cortico-cerebellar circuit formation and function.
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Affiliation(s)
- Claudius F Kratochwil
- Chair in Zoology and Evolutionary Biology, Department of Biology, University of KonstanzKonstanz, Germany.,Zukunftskolleg, University of KonstanzKonstanz, Germany
| | - Upasana Maheshwari
- Friedrich Miescher Institute for Biomedical ResearchBasel, Switzerland.,University of BaselBasel, Switzerland
| | - Filippo M Rijli
- Friedrich Miescher Institute for Biomedical ResearchBasel, Switzerland.,University of BaselBasel, Switzerland
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9
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Chen XY, Wang Y, Chen Y, Chen L, Wolpaw JR. The inferior olive is essential for long-term maintenance of a simple motor skill. J Neurophysiol 2016; 116:1946-1955. [PMID: 27535367 PMCID: PMC5144694 DOI: 10.1152/jn.00085.2016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 07/29/2016] [Indexed: 11/22/2022] Open
Abstract
The inferior olive (IO) is essential for operant down-conditioning of the rat soleus H-reflex, a simple motor skill. To evaluate the role of the IO in long-term maintenance of this skill, the H-reflex was down-conditioned over 50 days, the IO was chemically ablated, and down-conditioning continued for up to 102 more days. H-reflex size just before IO ablation averaged 62(±2 SE)% of its initial value (P < 0.001 vs. initial). After IO ablation, H-reflex size rose to 75-80% over ∼10 days, remained there for ∼30 days, rose over 10 days to above its initial value, and averaged 140(±14)% for the final 10 days of study (P < 0.01 vs. initial). This two-stage loss of down-conditioning maintenance correlated with IO neuronal loss (r = 0.75, P < 0.01) and was similar to the loss of down-conditioning that follows ablation of the cerebellar output nuclei dentate and interpositus. In control (i.e., unconditioned) rats, IO ablation has no long-term effect on H-reflex size. These results indicate that the IO is essential for long-term maintenance of a down-conditioned H-reflex. With previous data, they support the hypothesis that IO and cortical inputs to cerebellum combine to produce cerebellar plasticity that produces sensorimotor cortex plasticity that produces spinal cord plasticity that produces the smaller H-reflex. H-reflex down-conditioning appears to depend on a hierarchy of plasticity that may be guided by the IO and begin in the cerebellum. Similar hierarchies may underlie other motor learning.
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Affiliation(s)
- Xiang Yang Chen
- National Center for Adaptive Neurotechnologies, Wadsworth Center, New York State Department of Health, Albany, New York; .,Department of Biomedical Sciences, State University of New York, Albany, New York.,Albany Stratton Department of Veterans Affairs Medical Center, Albany, New York; and
| | - Yu Wang
- National Center for Adaptive Neurotechnologies, Wadsworth Center, New York State Department of Health, Albany, New York.,Albany Stratton Department of Veterans Affairs Medical Center, Albany, New York; and
| | - Yi Chen
- National Center for Adaptive Neurotechnologies, Wadsworth Center, New York State Department of Health, Albany, New York.,Albany Stratton Department of Veterans Affairs Medical Center, Albany, New York; and
| | - Lu Chen
- National Center for Adaptive Neurotechnologies, Wadsworth Center, New York State Department of Health, Albany, New York.,Albany Stratton Department of Veterans Affairs Medical Center, Albany, New York; and
| | - Jonathan R Wolpaw
- National Center for Adaptive Neurotechnologies, Wadsworth Center, New York State Department of Health, Albany, New York.,Department of Biomedical Sciences, State University of New York, Albany, New York.,Albany Stratton Department of Veterans Affairs Medical Center, Albany, New York; and.,Department of Neurology, Columbia University, College of Physicians and Surgeons, New York, New York
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10
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Papp EA, Leergaard TB, Csucs G, Bjaalie JG. Brain-Wide Mapping of Axonal Connections: Workflow for Automated Detection and Spatial Analysis of Labeling in Microscopic Sections. Front Neuroinform 2016; 10:11. [PMID: 27148038 PMCID: PMC4835481 DOI: 10.3389/fninf.2016.00011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 02/26/2016] [Indexed: 01/11/2023] Open
Abstract
Axonal tracing techniques are powerful tools for exploring the structural organization of neuronal connections. Tracers such as biotinylated dextran amine (BDA) and Phaseolus vulgaris leucoagglutinin (Pha-L) allow brain-wide mapping of connections through analysis of large series of histological section images. We present a workflow for efficient collection and analysis of tract-tracing datasets with a focus on newly developed modules for image processing and assignment of anatomical location to tracing data. New functionality includes automatic detection of neuronal labeling in large image series, alignment of images to a volumetric brain atlas, and analytical tools for measuring the position and extent of labeling. To evaluate the workflow, we used high-resolution microscopic images from axonal tracing experiments in which different parts of the rat primary somatosensory cortex had been injected with BDA or Pha-L. Parameters from a set of representative images were used to automate detection of labeling in image series covering the entire brain, resulting in binary maps of the distribution of labeling. For high to medium labeling densities, automatic detection was found to provide reliable results when compared to manual analysis, whereas weak labeling required manual curation for optimal detection. To identify brain regions corresponding to labeled areas, section images were aligned to the Waxholm Space (WHS) atlas of the Sprague Dawley rat brain (v2) by custom-angle slicing of the MRI template to match individual sections. Based on the alignment, WHS coordinates were obtained for labeled elements and transformed to stereotaxic coordinates. The new workflow modules increase the efficiency and reliability of labeling detection in large series of images from histological sections, and enable anchoring to anatomical atlases for further spatial analysis and comparison with other data.
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Affiliation(s)
- Eszter A Papp
- Institute of Basic Medical Sciences, University of Oslo Oslo, Norway
| | | | - Gergely Csucs
- Institute of Basic Medical Sciences, University of Oslo Oslo, Norway
| | - Jan G Bjaalie
- Institute of Basic Medical Sciences, University of Oslo Oslo, Norway
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11
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Chen XY, Wang Y, Chen Y, Chen L, Wolpaw JR. Ablation of the inferior olive prevents H-reflex down-conditioning in rats. J Neurophysiol 2016; 115:1630-6. [PMID: 26792888 DOI: 10.1152/jn.01069.2015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 01/16/2016] [Indexed: 01/01/2023] Open
Abstract
We evaluated the role of the inferior olive (IO) in acquisition of the spinal cord plasticity that underlies H-reflex down-conditioning, a simple motor skill. The IO was chemically ablated before a 50-day exposure to an operant conditioning protocol that rewarded a smaller soleus H-reflex. In normal rats, down-conditioning succeeds (i.e., H-reflex size decreases at least 20%) in 80% of animals. Down-conditioning failed in every IO-ablated rat (P< 0.001 vs. normal rats). IO ablation itself had no long-term effect on H-reflex size. These results indicate that the IO is essential for acquisition of a down-conditioned H-reflex. With previous data, they support the hypothesis that IO and cortical inputs to cerebellum enable the cerebellum to guide sensorimotor cortex plasticity that produces and maintains the spinal cord plasticity that underlies the down-conditioned H-reflex. They help to further define H-reflex conditioning as a model for understanding motor learning and as a new approach to enhancing functional recovery after trauma or disease.
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Affiliation(s)
- Xiang Yang Chen
- National Center for Adaptive Neurotechnologies, Wadsworth Center, New York State Department of Health, Albany, New York; Department of Biomedical Sciences, State University of New York, Albany, New York;
| | - Yu Wang
- National Center for Adaptive Neurotechnologies, Wadsworth Center, New York State Department of Health, Albany, New York
| | - Yi Chen
- National Center for Adaptive Neurotechnologies, Wadsworth Center, New York State Department of Health, Albany, New York
| | - Lu Chen
- National Center for Adaptive Neurotechnologies, Wadsworth Center, New York State Department of Health, Albany, New York
| | - Jonathan R Wolpaw
- National Center for Adaptive Neurotechnologies, Wadsworth Center, New York State Department of Health, Albany, New York; Department of Biomedical Sciences, State University of New York, Albany, New York; Department of Neurology, Albany Stratton Department of Veterans Affairs Medical Center, Albany, New York; and Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York
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12
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Chronic In Vivo Imaging of Ponto-Cerebellar Mossy Fibers Reveals Morphological Stability during Whisker Sensory Manipulation in the Adult Rat. eNeuro 2015; 2:eN-NWR-0075-15. [PMID: 26693178 PMCID: PMC4676200 DOI: 10.1523/eneuro.0075-15.2015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 09/04/2015] [Accepted: 09/28/2015] [Indexed: 11/29/2022] Open
Abstract
The cerebellum receives extensive disynaptic input from the neocortex via the basal pontine nuclei, the neurons of which send mossy fiber (MF) axons to the granule cell layer of the contralateral cerebellar hemisphere. Although this cortico-cerebellar circuit has been implicated in tasks such as sensory discrimination and motor learning, little is known about the potential role of MF morphological plasticity in the function of the cerebellar granule cell layer. To address this issue, we labeled MFs with EGFP via viral infection of the basal pons in adult rats and performed in vivo two-photon imaging of MFs in Crus I/II of the cerebellar hemisphere over a period of several weeks. Following the acquisition of baseline images, animals were housed in control, enriched, or deprived sensory environments. Morphological dynamics were assessed by tracing MF axons and their terminals, and by tracking the stability of filopodia arising from MF terminal rosettes. MF axons and terminals were found to be remarkably stable. Parameters derived neither from measurements of axonal arbor geometry nor from the morphology of individual rosettes and their filopodial extensions significantly changed under control conditions over 4 weeks of imaging. Increasing whisker stimulation by manipulating the sensory environment or decreasing such stimulation by whisker trimming also failed to alter MF structure. Our studies indicate that pontine MF axons projecting to Crus I/II in adult rats do not undergo significant structural rearrangements over the course of weeks, and that this stability is not altered by the sustained manipulation of whisker sensorimotor experience.
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13
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Zakiewicz IM, Majka P, Wójcik DK, Bjaalie JG, Leergaard TB. Three-Dimensional Histology Volume Reconstruction of Axonal Tract Tracing Data: Exploring Topographical Organization in Subcortical Projections from Rat Barrel Cortex. PLoS One 2015; 10:e0137571. [PMID: 26398192 PMCID: PMC4580429 DOI: 10.1371/journal.pone.0137571] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 08/18/2015] [Indexed: 11/18/2022] Open
Abstract
Topographical organization is a hallmark of the mammalian brain, and the spatial organization of axonal connections in different brain regions provides a structural framework accommodating specific patterns of neural activity. The presence, amount, and spatial distribution of axonal connections are typically studied in tract tracing experiments in which axons or neurons are labeled and examined in histological sections. Three-dimensional (3-D) reconstruction techniques are used to achieve more complete visualization and improved understanding of complex topographical relationships. 3-D reconstruction approaches based on manually or semi-automatically recorded spatial points representing axonal labeling have been successfully applied for investigation of smaller brain regions, but are not practically feasible for whole-brain analysis of multiple regions. We here reconstruct serial histological images from four whole brains (originally acquired for conventional microscopic analysis) into volumetric images that are spatially registered to a 3-D atlas template. The aims were firstly to evaluate the quality of the 3-D reconstructions and the usefulness of the approach, and secondly to investigate axonal projection patterns and topographical organization in rat corticostriatal and corticothalamic pathways. We demonstrate that even with the limitations of the original routine histological material, the 3-D reconstructed volumetric images allow efficient visualization of tracer injection sites and axonal labeling, facilitating detection of spatial distributions and across-case comparisons. Our results further show that clusters of S1 corticostriatal and corticothalamic projections are distributed within narrow, elongated or spherical subspaces extending across the entire striatum / thalamus. We conclude that histology volume reconstructions facilitate mapping of spatial distribution patterns and topographical organization. The reconstructed image volumes are shared via the Rodent Brain Workbench (www.rbwb.org).
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Affiliation(s)
- Izabela M. Zakiewicz
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
- Department of Neurophysiology, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Piotr Majka
- Department of Neurophysiology, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Daniel K. Wójcik
- Department of Neurophysiology, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Jan G. Bjaalie
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Trygve B. Leergaard
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
- * E-mail:
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14
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Ackerley R, Kavounoudias A. The role of tactile afference in shaping motor behaviour and implications for prosthetic innovation. Neuropsychologia 2015; 79:192-205. [PMID: 26102191 DOI: 10.1016/j.neuropsychologia.2015.06.024] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Revised: 06/02/2015] [Accepted: 06/17/2015] [Indexed: 10/23/2022]
Abstract
The present review focusses on how tactile somatosensory afference is encoded and processed, and how this information is interpreted and acted upon in terms of motor control. We relate the fundamental workings of the sensorimotor system to the rehabilitation of amputees using modern prosthetic interventions. Our sense of touch is central to our everyday lives, from allowing us to manipulate objects accurately to giving us a sense of self-embodiment. There are a variety of specialised cutaneous mechanoreceptive afferents, which differ in terms of type and density according to the skin site. In humans, there is a dense innervation of our hands, which is reflected in their vast over-representation in somatosensory and motor cortical areas. We review the accumulated evidence from animal and human studies about the precise interplay between the somatosensory and motor systems, which is highly integrated in many brain areas and often not separable. The glabrous hand skin provides exquisite, discriminative detail about touch, which is useful for refining movements. When these signals are disrupted, such as through injury or amputation, the consequences are considerable. The development of sensory feedback in prosthetics offers a promising avenue for the full integration of a missing body part. Real-time touch feedback from motor intentions aids in grip control and the ability to distinguish different surfaces, even introducing the possibility of pleasure in artificial touch. Thus, our knowledge from fundamental research into sensorimotor interactions should be used to develop more realistic and integrative prostheses.
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Affiliation(s)
- Rochelle Ackerley
- Department of Physiology, University of Gothenburg, Göteborg, Sweden; Laboratoire Neurosciences Intégratives et Adaptatives (UMR 7260), Aix Marseille Université - CNRS, Marseille, France.
| | - Anne Kavounoudias
- Laboratoire Neurosciences Intégratives et Adaptatives (UMR 7260), Aix Marseille Université - CNRS, Marseille, France
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15
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Abstract
Despite the attention attracted by “connectomics”, one can lose sight of the very real questions concerning “What are connections?” In the neuroimaging community, “structural” connectivity is ground truth and underlying constraint on “functional” or “effective” connectivity. It is referenced to underlying anatomy; but, as increasingly remarked, there is a large gap between the wealth of human brain mapping and the relatively scant data on actual anatomical connectivity. Moreover, connections have typically been discussed as “pairwise”, point x projecting to point y (or: to points y and z), or more recently, in graph theoretical terms, as “nodes” or regions and the interconnecting “edges”. This is a convenient shorthand, but tends not to capture the richness and nuance of basic anatomical properties as identified in the classic tradition of tracer studies. The present short review accordingly revisits connectional weights, heterogeneity, reciprocity, topography, and hierarchical organization, drawing on concrete examples. The emphasis is on presynaptic long-distance connections, motivated by the intention to probe current assumptions and promote discussions about further progress and synthesis.
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Affiliation(s)
- Kathleen S Rockland
- Department of Anatomy and Neurobiology, Boston University School of Medicine Boston, MA, USA ; Cold Spring Harbor Laboratory, Cold Spring Harbor NY, USA
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16
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Baizer JS. Unique features of the human brainstem and cerebellum. Front Hum Neurosci 2014; 8:202. [PMID: 24778611 PMCID: PMC3985031 DOI: 10.3389/fnhum.2014.00202] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Accepted: 03/21/2014] [Indexed: 12/28/2022] Open
Abstract
The cerebral cortex is greatly expanded in the human brain. There is a parallel expansion of the cerebellum, which is interconnected with the cerebral cortex. We have asked if there are accompanying changes in the organization of pre-cerebellar brainstem structures. We have examined the cytoarchitectonic and neurochemical organization of the human medulla and pons. We studied human cases from the Witelson Normal Brain Collection, analyzing Nissl sections and sections processed for immunohistochemistry for multiple markers including the calcium-binding proteins calbindin, calretinin, and parvalbumin, non-phosphorylated neurofilament protein, and the synthetic enzyme for nitric oxide, nitric oxide synthase. We have also compared the neurochemical organization of the human brainstem to that of several other species including the chimpanzee, macaque and squirrel monkey, cat, and rodent, again using Nissl staining and immunohistochemistry. We found that there are major differences in the human brainstem, ranging from relatively subtle differences in the neurochemical organization of structures found in each of the species studied to the emergence of altogether new structures in the human brainstem. Two aspects of human cortical organization, individual differences and left–right asymmetry, are also seen in the brainstem (principal nucleus of the inferior olive) and the cerebellum (the dentate nucleus). We suggest that uniquely human motor and cognitive abilities derive from changes at all levels of the central nervous system, including the cerebellum and brainstem, and not just the cerebral cortex.
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Affiliation(s)
- Joan S Baizer
- Department of Physiology and Biophysics, School of Medicine and Biomedical Sciences, University at Buffalo , Buffalo, NY , USA
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17
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Tonic inhibition enhances fidelity of sensory information transmission in the cerebellar cortex. J Neurosci 2012; 32:11132-43. [PMID: 22875944 DOI: 10.1523/jneurosci.0460-12.2012] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Tonic inhibition is a key regulator of neuronal excitability and network function in the brain, but its role in sensory information processing remains poorly understood. The cerebellum is a favorable model system for addressing this question as granule cells, which form the input layer of the cerebellar cortex, permit high-resolution patch-clamp recordings in vivo, and are the only neurons in the cerebellar cortex that express the α6δ-containing GABA(A) receptors mediating tonic inhibition. We investigated how tonic inhibition regulates sensory information transmission in the rat cerebellum by using a combination of intracellular recordings from granule cells and molecular layer interneurons in vivo, selective pharmacology, and in vitro dynamic clamp experiments. We show that blocking tonic inhibition significantly increases the spontaneous firing rate of granule cells while only moderately increasing sensory-evoked spike output. In contrast, enhancing tonic inhibition reduces the spike probability in response to sensory stimulation with minimal effect on the spontaneous spike rate. Both manipulations result in a reduction in the signal-to-noise ratio of sensory transmission in granule cells and of parallel fiber synaptic input to downstream molecular layer interneurons. These results suggest that under basal conditions the level of tonic inhibition in vivo enhances the fidelity of sensory information transmission through the input layer of the cerebellar cortex.
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18
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An internal model architecture for novelty detection: implications for cerebellar and collicular roles in sensory processing. PLoS One 2012; 7:e44560. [PMID: 22957083 PMCID: PMC3434152 DOI: 10.1371/journal.pone.0044560] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 08/06/2012] [Indexed: 11/20/2022] Open
Abstract
The cerebellum is thought to implement internal models for sensory prediction, but details of the underlying circuitry are currently obscure. We therefore investigated a specific example of internal-model based sensory prediction, namely detection of whisker contacts during whisking. Inputs from the vibrissae in rats can be affected by signals generated by whisker movement, a phenomenon also observable in whisking robots. Robot novelty-detection can be improved by adaptive noise-cancellation, in which an adaptive filter learns a forward model of the whisker plant that allows the sensory effects of whisking to be predicted and thus subtracted from the noisy sensory input. However, the forward model only uses information from an efference copy of the whisking commands. Here we show that the addition of sensory information from the whiskers allows the adaptive filter to learn a more complex internal model that performs more robustly than the forward model, particularly when the whisking-induced interference has a periodic structure. We then propose a neural equivalent of the circuitry required for adaptive novelty-detection in the robot, in which the role of the adaptive filter is carried out by the cerebellum, with the comparison of its output (an estimate of the self-induced interference) and the original vibrissal signal occurring in the superior colliculus, a structure noted for its central role in novelty detection. This proposal makes a specific prediction concerning the whisker-related functions of a region in cerebellar cortical zone A2 that in rats receives climbing fibre input from the superior colliculus (via the inferior olive). This region has not been observed in non-whisking animals such as cats and primates, and its functional role in vibrissal processing has hitherto remained mysterious. Further investigation of this system may throw light on how cerebellar-based internal models could be used in broader sensory, motor and cognitive contexts.
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Suzuki L, Coulon P, Sabel-Goedknegt EH, Ruigrok TJH. Organization of cerebral projections to identified cerebellar zones in the posterior cerebellum of the rat. J Neurosci 2012; 32:10854-69. [PMID: 22875920 PMCID: PMC6621006 DOI: 10.1523/jneurosci.0857-12.2012] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 06/18/2012] [Accepted: 06/19/2012] [Indexed: 12/25/2022] Open
Abstract
The cerebrocerebellar connection makes use of two of the largest fiber tracts in the mammalian brain, i.e., the cerebral and medial cerebellar peduncles. Neuroanatomical approaches aimed to elucidate the organization of this important connection have been hindered by its multisynaptic nature, the complex organization of its components, and the dependency of conventional tracers on precisely placed injections. To overcome these problems, we used rabies virus (RV) as a retrograde transneuronal tracer. RV was injected simultaneously with cholera toxin β subunit (CTb) into selected areas of the cerebellar cortex of 18 male Wistar rats. A survival time of 48-50 h resulted in first- and second-order labeling of RV in combination with first-order labeling of CTb. The distribution of CTb-labeled neurons in the inferior olive established the zonal identity of the injection site. In this way, it was possible to examine the cortical distribution of neurons from which disynaptic cerebrocerebellar projections to specific cerebellar loci originate. The results show that this distribution covaries with the identity of the injected cerebellar lobule. More subtle changes were present when different zones of the same lobule were injected. The C1 zone of lobule VIII receives a more prominent projection from the somatosensory cortex compared with the C2/D zones. The laterally positioned D zones receive information from more rostral regions of the cerebral cortex. The vermis of lobule VII receives a prominent input from the retrosplenial and orbitofrontal cortices. Different injection sites also result in differences in laterality of the connections.
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Affiliation(s)
- Lucia Suzuki
- Department of Neuroscience, Erasmus University Medical Center Rotterdam, 3000CA Rotterdam, The Netherlands, and
| | - Patrice Coulon
- Institut des Neurosciences de la Timone, CNRS and Aix-Marseille Université, 13385 Marseille Cedex 05, France
| | - Erika H. Sabel-Goedknegt
- Department of Neuroscience, Erasmus University Medical Center Rotterdam, 3000CA Rotterdam, The Netherlands, and
| | - Tom J. H. Ruigrok
- Department of Neuroscience, Erasmus University Medical Center Rotterdam, 3000CA Rotterdam, The Netherlands, and
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20
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Bosman LWJ, Houweling AR, Owens CB, Tanke N, Shevchouk OT, Rahmati N, Teunissen WHT, Ju C, Gong W, Koekkoek SKE, De Zeeuw CI. Anatomical pathways involved in generating and sensing rhythmic whisker movements. Front Integr Neurosci 2011; 5:53. [PMID: 22065951 PMCID: PMC3207327 DOI: 10.3389/fnint.2011.00053] [Citation(s) in RCA: 158] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 08/26/2011] [Indexed: 11/29/2022] Open
Abstract
The rodent whisker system is widely used as a model system for investigating sensorimotor integration, neural mechanisms of complex cognitive tasks, neural development, and robotics. The whisker pathways to the barrel cortex have received considerable attention. However, many subcortical structures are paramount to the whisker system. They contribute to important processes, like filtering out salient features, integration with other senses, and adaptation of the whisker system to the general behavioral state of the animal. We present here an overview of the brain regions and their connections involved in the whisker system. We do not only describe the anatomy and functional roles of the cerebral cortex, but also those of subcortical structures like the striatum, superior colliculus, cerebellum, pontomedullary reticular formation, zona incerta, and anterior pretectal nucleus as well as those of level setting systems like the cholinergic, histaminergic, serotonergic, and noradrenergic pathways. We conclude by discussing how these brain regions may affect each other and how they together may control the precise timing of whisker movements and coordinate whisker perception.
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Affiliation(s)
- Laurens W. J. Bosman
- Department of Neuroscience, Erasmus MCRotterdam, Netherlands
- Netherlands Institute for Neuroscience, Royal Academy of Arts and SciencesAmsterdam, Netherlands
| | | | - Cullen B. Owens
- Department of Neuroscience, Erasmus MCRotterdam, Netherlands
| | - Nouk Tanke
- Department of Neuroscience, Erasmus MCRotterdam, Netherlands
| | | | - Negah Rahmati
- Department of Neuroscience, Erasmus MCRotterdam, Netherlands
| | | | - Chiheng Ju
- Department of Neuroscience, Erasmus MCRotterdam, Netherlands
| | - Wei Gong
- Department of Neuroscience, Erasmus MCRotterdam, Netherlands
| | | | - Chris I. De Zeeuw
- Department of Neuroscience, Erasmus MCRotterdam, Netherlands
- Netherlands Institute for Neuroscience, Royal Academy of Arts and SciencesAmsterdam, Netherlands
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21
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Jung SH, Lee ST, Chu K, Park JE, Lee SU, Han TR, Kim M. Cell proliferation and synaptogenesis in the cerebellum after focal cerebral ischemia. Brain Res 2009; 1284:180-90. [DOI: 10.1016/j.brainres.2009.05.051] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Revised: 05/18/2009] [Accepted: 05/20/2009] [Indexed: 10/20/2022]
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22
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Chen YI, Wang FN, Nelson AJ, Xu H, Kim Y, Rosen BR, Kwong KK. Electrical stimulation modulates the amphetamine-induced hemodynamic changes: an fMRI study to compare the effect of stimulating locations and frequencies on rats. Neurosci Lett 2008; 444:117-21. [PMID: 18722508 DOI: 10.1016/j.neulet.2008.08.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2008] [Revised: 08/08/2008] [Accepted: 08/11/2008] [Indexed: 10/21/2022]
Abstract
UNLABELLED Our previous fMRI and microdialysis measurements showed that electroacupuncture (EA) at LI4 was effective in alleviating excessive cerebral dopamine release induced by d-amphetamine (AMPH) in rats. We now compare the effect of EA in adjusting excess dopamine release at two stimulating frequencies (2 Hz versus 100 Hz at LI4) and at two acupoints (forepaw (LI4) versus hindpaw (ST36), at 2 Hz). fMRI measurements of relative cerebral blood volume (rCBV) were used to monitor the brain activity of "rest", followed by AMPH challenge, 10 min "rest", and then 20 min of EA. RESULTS EA at LI4 and ST36 significantly attenuated the AMPH-induced rCBV increases in the striatum, S1 cortex, and thalamus. Frequency: EA at 100 Hz induced greater attenuation of rCBV than EA at 2 Hz in the S1, insula, anterior cingulate cortices, dorsolateral striatum, and thalamus. Acupoints: EA at LI4 modulated a broader area in the medial anterior striatum while EA at ST36 modulated a more site-specific area in the dorsolateral striatum. In the thalamus, EA at LI4 showed greater attenuating effect than EA at ST36 did. However, in the insular cortex, EA at ST36 showed stronger attenuation. CONCLUSION EA at both LI4 and ST36 was effective in restoring dopamine homeostasis from an excess state, with the most effective response at LI4 with 100 Hz, while the responses to 2Hz EA at LI4 and ST36 showed slightly different spatial distribution of MR signal. This therefore provided insight into the neurophysiological basis of electroacupuncture effects in cortical and subcortical circuits.
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Affiliation(s)
- Y Iris Chen
- Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.
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23
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Canals S, Beyerlein M, Keller AL, Murayama Y, Logothetis NK. Magnetic resonance imaging of cortical connectivity in vivo. Neuroimage 2008; 40:458-472. [PMID: 18222710 DOI: 10.1016/j.neuroimage.2007.12.007] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2007] [Revised: 11/22/2007] [Accepted: 12/03/2007] [Indexed: 11/26/2022] Open
Abstract
Magnetic resonance imaging of neuronal connectivity in vivo opens up the possibility of performing longitudinal investigations on neuronal networks. This is one main reason for the attention that paramagnetic ion manganese (Mn2+) has attracted as a potential anterograde neuronal tracer for MRI experiments. However, the correct and possibly repeated use of this tracer--or of any tracer for that matter, including heavy metals--requires the development of an administration strategy that minimizes its toxic effects. Here we first investigated the conditions that maximize the tracing efficiency of Mn2+ and preserve viability and tissue architectonics in combined MRI and histology experiments in rats. We demonstrate that most common protocols for neuronal tract tracing using Mn2+ result in large neuronal and glial lesions. The toxicity of manganese is distinct during intracortical injections and blocks the transfer of the tracer. After optimizing the technique, we could show that extensive cortical connectivity maps can be generated, with no sign of neuronal damage. Importantly, preservation of tissue viability improves the efficiency of Mn2+ in tracing neuronal connections. We have successfully used this technique to trace corticofugal somatosensory and motor pathways in individual animals and describe a connectivity index (CnI) based on Mn2+ transport that quantitatively reveals cortical heterogeneities in interhemispheric communication. Finally, we have significantly improved the resolution of the technique by continuously infusing very low concentrations of Mn2+ into the target area using osmotic pumps coupled to chronically implanted brain cannulae. The specific, nontoxic and quantitative nature of the neuronal tracings described here indicates the value of this tracer for chronic studies of development and plasticity as well as for studies of brain pathology.
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Affiliation(s)
- S Canals
- Max Planck Institute for Biological Cybernetics, 72076 Tübingen, Germany.
| | - M Beyerlein
- Max Planck Institute for Biological Cybernetics, 72076 Tübingen, Germany
| | - A L Keller
- Max Planck Institute for Biological Cybernetics, 72076 Tübingen, Germany
| | - Y Murayama
- Max Planck Institute for Biological Cybernetics, 72076 Tübingen, Germany
| | - N K Logothetis
- Max Planck Institute for Biological Cybernetics, 72076 Tübingen, Germany; Imaging Science and Biomedical Engineering University of Manchester, Manchester, UK.
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24
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Leergaard TB, Bjaalie JG. Topography of the complete corticopontine projection: from experiments to principal Maps. Front Neurosci 2007; 1:211-23. [PMID: 18982130 PMCID: PMC2518056 DOI: 10.3389/neuro.01.1.1.016.2007] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2007] [Accepted: 09/01/2007] [Indexed: 11/13/2022] Open
Abstract
The mammalian brain is characterized by orderly spatial distribution of its cellular components, commonly referred to as topographical organization. The topography of cortical and subcortical maps is thought to represent functional or computational properties. In the present investigation, we have studied map transformations and organizing principles in the projections from the cerebral cortex to the pontine nuclei, with emphasis on the mapping of the cortex as a whole onto the pontine nuclei. Following single or multiple axonal tracer injections into different cortical regions, three-dimensional (3-D) distributions of anterogradely labeled axons in the pontine nuclei were mapped. All 3-D reconstructed data sets were normalized to a standardized local coordinate system for the pontine nuclei and uploaded in a database application (FACCS, Functional Anatomy of the Cerebro-Cerebellar System, available via The Rodent Brain Workbench, http://www.rbwb.org). The database application allowed flexible use of the data in novel combinations, and use of a previously published data sets. Visualization of different combinations of data was used to explore alternative principles of organization. As a result of these analyses, a principal map of the topography of corticopontine projections was developed. This map followed the organization of early spatiotemporal gradients present in the cerebral cortex and the pontine nuclei. With the principal map for corticopontine projections, a fairly accurate prediction of pontine target area can be made for any site of origin in the cerebral cortex. The map and the underlying shared data sets represent a basis for modeling of topographical organization and structure-function relationships in this system.
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Affiliation(s)
- Trygve B Leergaard
- Centre for Molecular Biology and Neuroscience & Institute of Basic Medical Sciences, University of Oslo Norway
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25
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Helmstaedter M, de Kock CPJ, Feldmeyer D, Bruno RM, Sakmann B. Reconstruction of an average cortical column in silico. ACTA ACUST UNITED AC 2007; 55:193-203. [PMID: 17822776 DOI: 10.1016/j.brainresrev.2007.07.011] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2007] [Revised: 07/06/2007] [Accepted: 07/06/2007] [Indexed: 11/28/2022]
Abstract
The characterization of individual neurons by Golgi and Cajal has been the basis of neuroanatomy for a century. A new challenge is to anatomically describe, at cellular resolution, complete local circuits that can drive behavior. In this essay, we review the possibilities to obtain a model cortical column by using in vitro and in vivo pair recordings, followed by anatomical reconstructions of the projecting and target cells. These pairs establish connection modules that eventually may be useful to synthesize an average cortical column in silico. Together with data on sensory evoked neuronal activity measured in vivo, this will allow to model the anatomical and functional cellular basis of behavior based on more realistic assumptions than previously attempted.
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Affiliation(s)
- M Helmstaedter
- Department of Cell Physiology, Max-Planck-Institut für Medizinische Forschung, Jahnstrasse 29, Heidelberg, Germany
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26
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Bolstad I, Leergaard TB, Bjaalie JG. Branching of individual somatosensory cerebropontine axons in rat: evidence of divergence. Brain Struct Funct 2007; 212:85-93. [PMID: 17717700 DOI: 10.1007/s00429-007-0145-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2006] [Accepted: 05/09/2007] [Indexed: 12/21/2022]
Abstract
The cerebral cortex conveys major input to the granule cell layer of the cerebellar hemispheres by way of the pontine nuclei. Cerebrocortical projections terminate in multiple, widely distributed clusters in the pontine nuclei. This clustered organization is thought to provide the transition between the different organizational principles of the cerebrum and cerebellum, and indicates that parallel processing occurs at multiple sites in the pontine nuclei. At a cellular level, however, it is unknown whether individual cerebropontine neurons target pontocerebellar cells located in different clusters or not. We have employed anterograde axonal tracing and 3D computerized reconstruction techniques to characterize the branching pattern and morphology of individual cerebropontine axons from the primary somatosensory cortex (SI). Our findings show that 43% of the cerebrobulbar fibers arising from SI whisker representations provide two or three fibers entering the pontine nuclei, whereas 39% have only one fiber, and the remaining 18% do not project to the pontine nuclei. Thus, it appears that a majority of cerebropontine axons originating in SI whisker representations diverge to contact multiple, separated pontocerebellar cells. Further, 84% of the somatosensory cerebropontine fibers are collateral branches from cerebrobulbar and/or cerebrospinal parent fibers, while 16% are direct cerebropontine projections without a further descending projection. A range of thicknesses of the fibers entering the pontine nuclei were observed, with collaterals of corticobulbar fibers having the smallest diameter. Taken together, these findings may be related to previously described separate cerebropontine transmission lines with different properties.
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Affiliation(s)
- Ingeborg Bolstad
- Centre for Molecular Biology and Neuroscience, Institute of Basic Medical Sciences, University of Oslo, P.O Box 1105, Blindern, 0317 Oslo, Norway
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27
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Ioannides AA. Dynamic functional connectivity. Curr Opin Neurobiol 2007; 17:161-70. [PMID: 17379500 DOI: 10.1016/j.conb.2007.03.008] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Accepted: 03/13/2007] [Indexed: 12/31/2022]
Abstract
Recent studies show that anatomical and functional brain networks exhibit similar small-world properties. However, the networks that are compared often differ in what the nodes represent (e.g. sensors or brain areas), what kind of connectivity is measured, and what temporal and spatial scales are probed. Here, I review studies of large-scale connectivity and recent results from a variety of real-time recording techniques, which together suggest that an adequate description of brain organization requires a hierarchy of networks rather than the single, binary networks that are currently in vogue. Pattern analysis methods now offer a principled way for constructing such network hierarchies. As shown at the end of this review, a correspondence principle can be formulated to guide the interpretation across network levels and to relate nodes to well defined anatomical entities.
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Affiliation(s)
- Andreas A Ioannides
- Laboratory for Human Brain Dynamics, RIKEN Brain Science Institute, 2-1 Hirosawa, Wakoshi, Saitama, Japan 351-0198.
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28
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Moene IA, Subramaniam S, Darin D, Leergaard TB, Bjaalie JG. Toward a workbench for rodent brain image data systems architecture and design. Neuroinformatics 2007; 5:35-58. [PMID: 17426352 DOI: 10.1385/ni:5:1:35] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 11/11/2022]
Abstract
We present a novel system for storing and manipulating microscopic images from sections through the brain and higher-level data extracted from such images. The system is designed and built on a three-tier paradigm and provides the research community with a web-based interface for facile use in neuroscience research. The Oracle relational database management system provides the ability to store a variety of objects relevant to the images and provides the framework for complex querying of data stored in the system. Further, the suite of applications intimately tied into the infrastructure in the application layer provide the user the ability not only to query and visualize the data, but also to perform analysis operations based on the tools embedded into the system. The presentation layer uses extant protocols of the modern web browser and this provides ease of use of the system. The present release, named Functional Anatomy of the Cerebro-Cerebellar System (FACCS), available through The Rodent Brain Workbench (http:// rbwb.org/), is targeted at the functional anatomy of the cerebro-cerebellar system in rats, and holds axonal tracing data from these projections. The system is extensible to other circuits and projections and to other categories of image data and provides a unique environment for analysis of rodent brain maps in the context of anatomical data. The FACCS application assumes standard animal brain atlas models and can be extended to future models. The system is available both for interactive use from a remote web-browser client as well as for download to a local server machine.
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Affiliation(s)
- Ivar A Moene
- Neural Systems and Graphics Computing Laboratory, Centre for Molecular Biology and Neuroscience & Institute of Basic Medical Sciences, University of Oslo, PO Box 1105 Blindern, N-0317 Oslo, Norway
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