1
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Vignoud G, Venance L, Touboul JD. Anti-Hebbian plasticity drives sequence learning in striatum. Commun Biol 2024; 7:555. [PMID: 38724614 PMCID: PMC11082161 DOI: 10.1038/s42003-024-06203-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 04/17/2024] [Indexed: 05/12/2024] Open
Abstract
Spatio-temporal activity patterns have been observed in a variety of brain areas in spontaneous activity, prior to or during action, or in response to stimuli. Biological mechanisms endowing neurons with the ability to distinguish between different sequences remain largely unknown. Learning sequences of spikes raises multiple challenges, such as maintaining in memory spike history and discriminating partially overlapping sequences. Here, we show that anti-Hebbian spike-timing dependent plasticity (STDP), as observed at cortico-striatal synapses, can naturally lead to learning spike sequences. We design a spiking model of the striatal output neuron receiving spike patterns defined as sequential input from a fixed set of cortical neurons. We use a simple synaptic plasticity rule that combines anti-Hebbian STDP and non-associative potentiation for a subset of the presented patterns called rewarded patterns. We study the ability of striatal output neurons to discriminate rewarded from non-rewarded patterns by firing only after the presentation of a rewarded pattern. In particular, we show that two biological properties of striatal networks, spiking latency and collateral inhibition, contribute to an increase in accuracy, by allowing a better discrimination of partially overlapping sequences. These results suggest that anti-Hebbian STDP may serve as a biological substrate for learning sequences of spikes.
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Affiliation(s)
- Gaëtan Vignoud
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, Paris, France
| | - Laurent Venance
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, Paris, France.
| | - Jonathan D Touboul
- Department of Mathematics and Volen National Center for Complex Systems, Brandeis University, Waltham, MA, USA.
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2
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Petroccione MA, D'Brant LY, Affinnih N, Wehrle PH, Todd GC, Zahid S, Chesbro HE, Tschang IL, Scimemi A. Neuronal glutamate transporters control reciprocal inhibition and gain modulation in D1 medium spiny neurons. eLife 2023; 12:e81830. [PMID: 37435808 PMCID: PMC10411972 DOI: 10.7554/elife.81830] [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: 07/13/2022] [Accepted: 07/09/2023] [Indexed: 07/13/2023] Open
Abstract
Understanding the function of glutamate transporters has broad implications for explaining how neurons integrate information and relay it through complex neuronal circuits. Most of what is currently known about glutamate transporters, specifically their ability to maintain glutamate homeostasis and limit glutamate diffusion away from the synaptic cleft, is based on studies of glial glutamate transporters. By contrast, little is known about the functional implications of neuronal glutamate transporters. The neuronal glutamate transporter EAAC1 is widely expressed throughout the brain, particularly in the striatum, the primary input nucleus of the basal ganglia, a region implicated with movement execution and reward. Here, we show that EAAC1 limits synaptic excitation onto a population of striatal medium spiny neurons identified for their expression of D1 dopamine receptors (D1-MSNs). In these cells, EAAC1 also contributes to strengthen lateral inhibition from other D1-MSNs. Together, these effects contribute to reduce the gain of the input-output relationship and increase the offset at increasing levels of synaptic inhibition in D1-MSNs. By reducing the sensitivity and dynamic range of action potential firing in D1-MSNs, EAAC1 limits the propensity of mice to rapidly switch between behaviors associated with different reward probabilities. Together, these findings shed light on some important molecular and cellular mechanisms implicated with behavior flexibility in mice.
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Affiliation(s)
| | | | | | | | | | - Shergil Zahid
- SUNY Albany, Department of BiologyAlbanyUnited States
| | | | - Ian L Tschang
- SUNY Albany, Department of BiologyAlbanyUnited States
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3
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Perez S, Cui Y, Vignoud G, Perrin E, Mendes A, Zheng Z, Touboul J, Venance L. Striatum expresses region-specific plasticity consistent with distinct memory abilities. Cell Rep 2022; 38:110521. [PMID: 35294877 DOI: 10.1016/j.celrep.2022.110521] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 12/23/2021] [Accepted: 02/21/2022] [Indexed: 11/24/2022] Open
Abstract
The striatum mediates two learning modalities: goal-directed behavior in dorsomedial (DMS) and habits in dorsolateral (DLS) striata. The synaptic bases of these learnings are still elusive. Indeed, while ample research has described DLS plasticity, little remains known about DMS plasticity and its involvement in procedural learning. Here, we find symmetric and asymmetric anti-Hebbian spike-timing-dependent plasticity (STDP) in DMS and DLS, respectively, with opposite plasticity dominance upon increasing corticostriatal activity. During motor-skill learning, plasticity is engaged in DMS and striatonigral DLS neurons only during early learning stages, whereas striatopallidal DLS neurons are mobilized only during late phases. With a mathematical modeling approach, we find that symmetric anti-Hebbian STDP favors memory flexibility, while asymmetric anti-Hebbian STDP favors memory maintenance, consistent with memory processes at play in procedural learning.
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Affiliation(s)
- Sylvie Perez
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, Paris, France
| | - Yihui Cui
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, Paris, France; Department of Neurobiology, Department of Neurology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Gaëtan Vignoud
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, Paris, France; MAMBA-Modelling and Analysis for Medical and Biological Applications, Inria Paris, LJLL (UMR-7598) -Laboratory Jacques-Louis Lions, Paris, France
| | - Elodie Perrin
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, Paris, France
| | - Alexandre Mendes
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, Paris, France
| | - Zhiwei Zheng
- Department of Neurobiology, Department of Neurology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Jonathan Touboul
- Department of Mathematics and Volen National Center for Complex Systems, Brandeis University, Waltham, MA, USA
| | - Laurent Venance
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, Paris, France.
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4
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Lepping RJ, McKinney WS, Magnon GC, Keedy SK, Wang Z, Coombes SA, Vaillancourt DE, Sweeney JA, Mosconi MW. Visuomotor brain network activation and functional connectivity among individuals with autism spectrum disorder. Hum Brain Mapp 2021; 43:844-859. [PMID: 34716740 PMCID: PMC8720186 DOI: 10.1002/hbm.25692] [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: 04/05/2021] [Revised: 09/08/2021] [Accepted: 10/12/2021] [Indexed: 12/26/2022] Open
Abstract
Sensorimotor abnormalities are common in autism spectrum disorder (ASD) and predictive of functional outcomes, though their neural underpinnings remain poorly understood. Using functional magnetic resonance imaging, we examined both brain activation and functional connectivity during visuomotor behavior in 27 individuals with ASD and 30 typically developing (TD) controls (ages 9–35 years). Participants maintained a constant grip force while receiving visual feedback at three different visual gain levels. Relative to controls, ASD participants showed increased force variability, especially at high gain, and reduced entropy. Brain activation was greater in individuals with ASD than controls in supplementary motor area, bilateral superior parietal lobules, and contralateral middle frontal gyrus at high gain. During motor action, functional connectivity was reduced between parietal‐premotor and parietal‐putamen in individuals with ASD compared to controls. Individuals with ASD also showed greater age‐associated increases in functional connectivity between cerebellum and visual, motor, and prefrontal cortical areas relative to controls. These results indicate that visuomotor deficits in ASD are associated with atypical activation and functional connectivity of posterior parietal, premotor, and striatal circuits involved in translating sensory feedback information into precision motor behaviors, and that functional connectivity of cerebellar–cortical sensorimotor and nonsensorimotor networks show delayed maturation.
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Affiliation(s)
- Rebecca J Lepping
- Hoglund Biomedical Imaging Center, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Walker S McKinney
- Schiefelbusch Institute for Life Span Studies, Clinical Child Psychology Program, and Kansas Center for Autism Research and Training (K-CART), University of Kansas, Lawrence, Kansas, USA
| | - Grant C Magnon
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Sarah K Keedy
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, Illinois, USA
| | - Zheng Wang
- Department of Occupational Therapy, University of Florida, Gainesville, Florida, USA.,Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
| | - Stephen A Coombes
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
| | - David E Vaillancourt
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
| | - John A Sweeney
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Matthew W Mosconi
- Schiefelbusch Institute for Life Span Studies, Clinical Child Psychology Program, and Kansas Center for Autism Research and Training (K-CART), University of Kansas, Lawrence, Kansas, USA
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5
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Humphries MD, Gurney K. Making decisions in the dark basement of the brain: A look back at the GPR model of action selection and the basal ganglia. BIOLOGICAL CYBERNETICS 2021; 115:323-329. [PMID: 34272969 DOI: 10.1007/s00422-021-00887-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 07/06/2021] [Indexed: 06/13/2023]
Abstract
How does your brain decide what you will do next? Over the past few decades compelling evidence has emerged that the basal ganglia, a collection of nuclei in the fore- and mid-brain of all vertebrates, are vital to action selection. Gurney, Prescott, and Redgrave published an influential computational account of this idea in Biological Cybernetics in 2001. Here we take a look back at this pair of papers, outlining the "GPR" model contained therein, the context of that model's development, and the influence it has had over the past twenty years. Tracing its lineage into models and theories still emerging now, we are encouraged that the GPR model is that rare thing, a computational model of a brain circuit whose advances were directly built on by others.
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6
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Comhair J, Devoght J, Morelli G, Harvey RJ, Briz V, Borrie SC, Bagni C, Rigo JM, Schiffmann SN, Gall D, Brône B, Molchanova SM. Alpha2-Containing Glycine Receptors Promote Neonatal Spontaneous Activity of Striatal Medium Spiny Neurons and Support Maturation of Glutamatergic Inputs. Front Mol Neurosci 2018; 11:380. [PMID: 30374290 PMCID: PMC6196267 DOI: 10.3389/fnmol.2018.00380] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 09/24/2018] [Indexed: 12/16/2022] Open
Abstract
Glycine receptors (GlyRs) containing the α2 subunit are highly expressed in the developing brain, where they regulate neuronal migration and maturation, promote spontaneous network activity and subsequent development of synaptic connections. Mutations in GLRA2 are associated with autism spectrum disorder, but the underlying pathophysiology is not described yet. Here, using Glra2-knockout mice, we found a GlyR-dependent effect on neonatal spontaneous activity of dorsal striatum medium spiny neurons (MSNs) and maturation of the incoming glutamatergic innervation. Our data demonstrate that functional GlyRs are highly expressed in MSNs of one-week-old mice, but they do not generate endogenous chloride-mediated tonic or phasic current. Despite of that, knocking out the Glra2 severely affects the shape of action potentials and impairs spontaneous activity and the frequency of miniature AMPA receptor-mediated currents in MSNs. This reduction in spontaneous activity and glutamatergic signaling can attribute to the observed changes in neonatal behavioral phenotypes as seen in ultrasonic vocalizations and righting reflex. In adult Glra2-knockout animals, the glutamatergic synapses in MSNs remain functionally underdeveloped. The number of glutamatergic synapses and release probability at presynaptic site remain unaffected, but the amount of postsynaptic AMPA receptors is decreased. This deficit is a consequence of impaired development of the neuronal circuitry since acute inhibition of GlyRs by strychnine in adult MSNs does not affect the properties of glutamatergic synapses. Altogether, these results demonstrate that GlyR-mediated signaling supports neonatal spontaneous MSN activity and, in consequence, promotes the functional maturation of glutamatergic synapses on MSNs. The described mechanism might shed light on the pathophysiological mechanisms in GLRA2-linked autism spectrum disorder cases.
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Affiliation(s)
- Joris Comhair
- Laboratory of Neurophysiology, ULB-Neuroscience Institute, Université Libre de Bruxelles, Brussels, Belgium.,BIOMED Research Institute, University of Hasselt, Hasselt, Belgium
| | - Jens Devoght
- BIOMED Research Institute, University of Hasselt, Hasselt, Belgium
| | - Giovanni Morelli
- BIOMED Research Institute, University of Hasselt, Hasselt, Belgium
| | - Robert J Harvey
- School of Health and Sport Sciences, University of the Sunshine Coast, Sippy Downs, QLD, Australia.,Sunshine Coast Health Institute, Birtinya, QLD, Australia
| | - Victor Briz
- Center for Human Genetics and Leuven Research Institute for Neuroscience and Disease, KU Leuven, Leuven, Belgium.,VIB Center for the Biology of Disease, Leuven, Belgium
| | - Sarah C Borrie
- Center for Human Genetics and Leuven Research Institute for Neuroscience and Disease, KU Leuven, Leuven, Belgium.,VIB Center for the Biology of Disease, Leuven, Belgium
| | - Claudia Bagni
- Center for Human Genetics and Leuven Research Institute for Neuroscience and Disease, KU Leuven, Leuven, Belgium.,VIB Center for the Biology of Disease, Leuven, Belgium
| | - Jean-Michel Rigo
- BIOMED Research Institute, University of Hasselt, Hasselt, Belgium
| | - Serge N Schiffmann
- Laboratory of Neurophysiology, ULB-Neuroscience Institute, Université Libre de Bruxelles, Brussels, Belgium
| | - David Gall
- Laboratory of Neurophysiology, ULB-Neuroscience Institute, Université Libre de Bruxelles, Brussels, Belgium
| | - Bert Brône
- BIOMED Research Institute, University of Hasselt, Hasselt, Belgium
| | - Svetlana M Molchanova
- Laboratory of Neurophysiology, ULB-Neuroscience Institute, Université Libre de Bruxelles, Brussels, Belgium
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7
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Bahuguna J, Weidel P, Morrison A. Exploring the role of striatal D1 and D2 medium spiny neurons in action selection using a virtual robotic framework. Eur J Neurosci 2018; 49:737-753. [PMID: 29917291 PMCID: PMC6585768 DOI: 10.1111/ejn.14021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 05/15/2018] [Accepted: 06/06/2018] [Indexed: 11/30/2022]
Abstract
The basal ganglia have been hypothesized to be involved in action selection, i.e. resolving competition between simultaneously activated motor programs. It has been shown that the direct pathway facilitates action execution whereas the indirect pathway inhibits it. However, as the pathways are both active during an action, it remains unclear whether their role is co-operative or competitive. In order to investigate this issue, we developed a striatal model consisting of D1 and D2 medium spiny neurons (MSNs) and interfaced it to a simulated robot moving in an environment. We demonstrate that this model is able to reproduce key behavioral features of several experiments involving optogenetic manipulation of the striatum, such as freezing and ambulation. We then investigate the interaction of D1- and D2-MSNs. We find that their fundamental relationship is co-operative within a channel and competitive between channels; this turns out to be crucial for action selection. However, individual pairs of D1- and D2-MSNs may exhibit predominantly competition or co-operation depending on their distance, and D1- and D2-MSNs population activity can alternate between co-operation and competition modes during a stimulation. Additionally, our results show that D2-D2 connectivity between channels is necessary for effective resolution of competition; in its absence, a conflict of two motor programs typically results in neither being selected.
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Affiliation(s)
- Jyotika Bahuguna
- Institute for Advanced Simulation (IAS-6), Institute of Neuroscience and Medicine (INM-6) and JARA Institute Brain Structure-Function Relationships (JBI-1/INM-10), Jülich Research Centre, Jülich, 52428, Germany
| | - Philipp Weidel
- Institute for Advanced Simulation (IAS-6), Institute of Neuroscience and Medicine (INM-6) and JARA Institute Brain Structure-Function Relationships (JBI-1/INM-10), Jülich Research Centre, Jülich, 52428, Germany
| | - Abigail Morrison
- Institute for Advanced Simulation (IAS-6), Institute of Neuroscience and Medicine (INM-6) and JARA Institute Brain Structure-Function Relationships (JBI-1/INM-10), Jülich Research Centre, Jülich, 52428, Germany.,Institute for Cognitive Neurosciences, Ruhr University, Bochum, Germany
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8
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Lindroos R, Dorst MC, Du K, Filipović M, Keller D, Ketzef M, Kozlov AK, Kumar A, Lindahl M, Nair AG, Pérez-Fernández J, Grillner S, Silberberg G, Hellgren Kotaleski J. Basal Ganglia Neuromodulation Over Multiple Temporal and Structural Scales-Simulations of Direct Pathway MSNs Investigate the Fast Onset of Dopaminergic Effects and Predict the Role of Kv4.2. Front Neural Circuits 2018; 12:3. [PMID: 29467627 PMCID: PMC5808142 DOI: 10.3389/fncir.2018.00003] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 01/09/2018] [Indexed: 12/16/2022] Open
Abstract
The basal ganglia are involved in the motivational and habitual control of motor and cognitive behaviors. Striatum, the largest basal ganglia input stage, integrates cortical and thalamic inputs in functionally segregated cortico-basal ganglia-thalamic loops, and in addition the basal ganglia output nuclei control targets in the brainstem. Striatal function depends on the balance between the direct pathway medium spiny neurons (D1-MSNs) that express D1 dopamine receptors and the indirect pathway MSNs that express D2 dopamine receptors. The striatal microstructure is also divided into striosomes and matrix compartments, based on the differential expression of several proteins. Dopaminergic afferents from the midbrain and local cholinergic interneurons play crucial roles for basal ganglia function, and striatal signaling via the striosomes in turn regulates the midbrain dopaminergic system directly and via the lateral habenula. Consequently, abnormal functions of the basal ganglia neuromodulatory system underlie many neurological and psychiatric disorders. Neuromodulation acts on multiple structural levels, ranging from the subcellular level to behavior, both in health and disease. For example, neuromodulation affects membrane excitability and controls synaptic plasticity and thus learning in the basal ganglia. However, it is not clear on what time scales these different effects are implemented. Phosphorylation of ion channels and the resulting membrane effects are typically studied over minutes while it has been shown that neuromodulation can affect behavior within a few hundred milliseconds. So how do these seemingly contradictory effects fit together? Here we first briefly review neuromodulation of the basal ganglia, with a focus on dopamine. We furthermore use biophysically detailed multi-compartmental models to integrate experimental data regarding dopaminergic effects on individual membrane conductances with the aim to explain the resulting cellular level dopaminergic effects. In particular we predict dopaminergic effects on Kv4.2 in D1-MSNs. Finally, we also explore dynamical aspects of the onset of neuromodulation effects in multi-scale computational models combining biochemical signaling cascades and multi-compartmental neuron models.
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Affiliation(s)
- Robert Lindroos
- Department of Neuroscience, Nobel Institute for Neurophysiology, Stockholm, Sweden
| | - Matthijs C. Dorst
- Department of Neuroscience, Nobel Institute for Neurophysiology, Stockholm, Sweden
| | - Kai Du
- Department of Neuroscience, Nobel Institute for Neurophysiology, Stockholm, Sweden
| | - Marko Filipović
- Bernstein Center Freiburg, University of Freiburg, Freiburg im Breisgau, Germany
| | - Daniel Keller
- Blue Brain Project, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Maya Ketzef
- Department of Neuroscience, Nobel Institute for Neurophysiology, Stockholm, Sweden
| | - Alexander K. Kozlov
- Science for Life Laboratory, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, Solna, Sweden
| | - Arvind Kumar
- Bernstein Center Freiburg, University of Freiburg, Freiburg im Breisgau, Germany
- Department Computational Science and Technology, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Mikael Lindahl
- Science for Life Laboratory, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, Solna, Sweden
| | - Anu G. Nair
- Science for Life Laboratory, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, Solna, Sweden
| | - Juan Pérez-Fernández
- Department of Neuroscience, Nobel Institute for Neurophysiology, Stockholm, Sweden
| | - Sten Grillner
- Department of Neuroscience, Nobel Institute for Neurophysiology, Stockholm, Sweden
| | - Gilad Silberberg
- Department of Neuroscience, Nobel Institute for Neurophysiology, Stockholm, Sweden
| | - Jeanette Hellgren Kotaleski
- Department of Neuroscience, Nobel Institute for Neurophysiology, Stockholm, Sweden
- Science for Life Laboratory, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, Solna, Sweden
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9
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Burke DA, Rotstein HG, Alvarez VA. Striatal Local Circuitry: A New Framework for Lateral Inhibition. Neuron 2017; 96:267-284. [PMID: 29024654 DOI: 10.1016/j.neuron.2017.09.019] [Citation(s) in RCA: 137] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 08/09/2017] [Accepted: 09/12/2017] [Indexed: 12/01/2022]
Abstract
This Perspective will examine the organization of intrastriatal circuitry, review recent findings in this area, and discuss how the pattern of connectivity between striatal neurons might give rise to the behaviorally observed synergism between the direct/indirect pathway neurons. The emphasis of this Perspective is on the underappreciated role of lateral inhibition between striatal projection cells in controlling neuronal firing and shaping the output of this circuit. We review some classic studies in combination with more recent anatomical and functional findings to lay out a framework for an updated model of the intrastriatal lateral inhibition, where we explore its contribution to the formation of functional units of processing and the integration and filtering of inputs to generate motor patterns and learned behaviors.
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Affiliation(s)
- Dennis A Burke
- Laboratory on Neurobiology of Compulsive Behaviors, Intramural Research Program, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD 20892, USA; Department of Neuroscience, Brown University, Providence, Providence, RI 02912, USA
| | - Horacio G Rotstein
- Federated Department of Biological Sciences, New Jersey Institute of Technology and Rutgers University, Newark, NJ 07102, USA; Institute for Brain and Neuroscience Research, New Jersey Institute of Technology, Newark, NJ 07102, USA
| | - Veronica A Alvarez
- Laboratory on Neurobiology of Compulsive Behaviors, Intramural Research Program, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD 20892, USA; Intramural Research Program, National Institute on Drug Abuse, NIH, Baltimore, MD 21224, USA.
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10
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Activity Dynamics and Signal Representation in a Striatal Network Model with Distance-Dependent Connectivity. eNeuro 2017; 4:eN-TNC-0348-16. [PMID: 28840190 PMCID: PMC5566799 DOI: 10.1523/eneuro.0348-16.2017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 07/06/2017] [Accepted: 07/07/2017] [Indexed: 12/04/2022] Open
Abstract
The striatum is the main input nucleus of the basal ganglia. Characterizing striatal activity dynamics is crucial to understanding mechanisms underlying action selection, initiation, and execution. Here, we studied the effects of spatial network connectivity on the spatiotemporal structure of striatal activity. We show that a striatal network with nonmonotonically changing distance-dependent connectivity (according to a gamma distribution) can exhibit a wide repertoire of spatiotemporal dynamics, ranging from spatially homogeneous, asynchronous-irregular (AI) activity to a state with stable, spatially localized activity bumps, as in “winner-take-all” (WTA) dynamics. Among these regimes, the unstable activity bumps [transition activity (TA)] regime closely resembles the experimentally observed spatiotemporal activity dynamics and neuronal assemblies in the striatum. In contrast, striatal networks with monotonically decreasing distance-dependent connectivity (in a Gaussian fashion) can exhibit only an AI state. Thus, given the observation of spatially compact neuronal clusters in the striatum, our model suggests that recurrent connectivity among striatal projection neurons should vary nonmonotonically. In brain disorders such as Parkinson’s disease, increased cortical inputs and high striatal firing rates are associated with a reduction in stimulus sensitivity. Consistent with this, our model suggests that strong cortical inputs drive the striatum to a WTA state, leading to low stimulus sensitivity and high variability. In contrast, the AI and TA states show high stimulus sensitivity and reliability. Thus, based on these results, we propose that in a healthy state the striatum operates in a AI/TA state and that lack of dopamine pushes it into a WTA state.
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11
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Pallidostriatal Projections Promote β Oscillations in a Dopamine-Depleted Biophysical Network Model. J Neurosci 2017; 36:5556-71. [PMID: 27194335 DOI: 10.1523/jneurosci.0339-16.2016] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 04/12/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED In the basal ganglia, focused rhythmicity is an important feature of network activity at certain stages of motor processing. In disease, however, the basal ganglia develop amplified rhythmicity. Here, we demonstrate how the cellular architecture and network dynamics of an inhibitory loop in the basal ganglia yield exaggerated synchrony and locking to β oscillations, specifically in the dopamine-depleted state. A key component of this loop is the pallidostriatal pathway, a well-characterized anatomical projection whose function has long remained obscure. We present a synaptic characterization of this pathway in mice and incorporate these data into a computational model that we use to investigate its influence over striatal activity under simulated healthy and dopamine-depleted conditions. Our model predicts that the pallidostriatal pathway influences striatal output preferentially during periods of synchronized activity within GPe. We show that, under dopamine-depleted conditions, this effect becomes a key component of a positive feedback loop between the GPe and striatum that promotes synchronization and rhythmicity. Our results generate novel predictions about the role of the pallidostriatal pathway in shaping basal ganglia activity in health and disease. SIGNIFICANCE STATEMENT This work demonstrates that functional connections from the globus pallidus externa (GPe) to striatum are substantially stronger onto fast-spiking interneurons (FSIs) than onto medium spiny neurons. Our circuit model suggests that when GPe spikes are synchronous, this pallidostriatal pathway causes synchronous FSI activity pauses, which allow a transient window of disinhibition for medium spiny neurons. In simulated dopamine-depletion, this GPe-FSI activity is necessary for the emergence of strong synchronization and the amplification and propagation of β oscillations, which are a hallmark of parkinsonian circuit dysfunction. These results suggest that GPe may play a central role in propagating abnormal circuit activity to striatum, which in turn projects to downstream basal ganglia structures. These findings warrant further exploration of GPe as a target for interventions for Parkinson's disease.
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12
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Belić JJ, Kumar A, Hellgren Kotaleski J. Interplay between periodic stimulation and GABAergic inhibition in striatal network oscillations. PLoS One 2017; 12:e0175135. [PMID: 28384268 PMCID: PMC5383243 DOI: 10.1371/journal.pone.0175135] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 03/21/2017] [Indexed: 11/19/2022] Open
Abstract
Network oscillations are ubiquitous across many brain regions. In the basal ganglia, oscillations are also present at many levels and a wide range of characteristic frequencies have been reported to occur during both health and disease. The striatum, the main input nucleus of the basal ganglia, receives massive glutamatergic inputs from the cortex and is highly susceptible to external oscillations. However, there is limited knowledge about the exact nature of this routing process and therefore, it is of key importance to understand how time-dependent, external stimuli propagate through the striatal circuitry. Using a network model of the striatum and corticostriatal projections, we try to elucidate the importance of specific GABAergic neurons and their interactions in shaping striatal oscillatory activity. Here, we propose that fast-spiking interneurons can perform an important role in transferring cortical oscillations to the striatum especially to those medium spiny neurons that are not directly driven by the cortical oscillations. We show how the activity levels of different populations, the strengths of different inhibitory synapses, degree of outgoing projections of striatal cells, ongoing activity and synchronicity of inputs can influence network activity. These results suggest that the propagation of oscillatory inputs into the medium spiny neuron population is most efficient, if conveyed via the fast-spiking interneurons. Therefore, pharmaceuticals that target fast-spiking interneurons may provide a novel treatment for regaining the spectral characteristics of striatal activity that correspond to the healthy state.
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Affiliation(s)
- Jovana J. Belić
- Science for Life Laboratory, School of Computer Science and Communication, KTH Royal Institute of Technology, Stockholm, Sweden
- Department of Computational Science and Technology, School of Computer Science and Communication, KTH Royal Institute of Technology, Stockholm, Sweden
- Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
| | - Arvind Kumar
- Department of Computational Science and Technology, School of Computer Science and Communication, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Jeanette Hellgren Kotaleski
- Science for Life Laboratory, School of Computer Science and Communication, KTH Royal Institute of Technology, Stockholm, Sweden
- Department of Computational Science and Technology, School of Computer Science and Communication, KTH Royal Institute of Technology, Stockholm, Sweden
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
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13
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Fuccillo MV. Striatal Circuits as a Common Node for Autism Pathophysiology. Front Neurosci 2016; 10:27. [PMID: 26903795 PMCID: PMC4746330 DOI: 10.3389/fnins.2016.00027] [Citation(s) in RCA: 160] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 01/22/2016] [Indexed: 12/17/2022] Open
Abstract
Autism spectrum disorders (ASD) are characterized by two seemingly unrelated symptom domains-deficits in social interactions and restrictive, repetitive patterns of behavioral output. Whether the diverse nature of ASD symptomatology represents distributed dysfunction of brain networks or abnormalities within specific neural circuits is unclear. Striatal dysfunction is postulated to underlie the repetitive motor behaviors seen in ASD, and neurological and brain-imaging studies have supported this assumption. However, as our appreciation of striatal function expands to include regulation of behavioral flexibility, motivational state, goal-directed learning, and attention, we consider whether alterations in striatal physiology are a central node mediating a range of autism-associated behaviors, including social and cognitive deficits that are hallmarks of the disease. This review investigates multiple genetic mouse models of ASD to explore whether abnormalities in striatal circuits constitute a common pathophysiological mechanism in the development of autism-related behaviors. Despite the heterogeneity of genetic insult investigated, numerous genetic ASD models display alterations in the structure and function of striatal circuits, as well as abnormal behaviors including repetitive grooming, stereotypic motor routines, deficits in social interaction and decision-making. Comparative analysis in rodents provides a unique opportunity to leverage growing genetic association data to reveal canonical neural circuits whose dysfunction directly contributes to discrete aspects of ASD symptomatology. The description of such circuits could provide both organizing principles for understanding the complex genetic etiology of ASD as well as novel treatment routes. Furthermore, this focus on striatal mechanisms of behavioral regulation may also prove useful for exploring the pathogenesis of other neuropsychiatric diseases, which display overlapping behavioral deficits with ASD.
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Affiliation(s)
- Marc V. Fuccillo
- Department of Neuroscience, Perelman School of Medicine, University of PennsylvaniaPhiladelphia, PA, USA
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14
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Bakhurin KI, Mac V, Golshani P, Masmanidis SC. Temporal correlations among functionally specialized striatal neural ensembles in reward-conditioned mice. J Neurophysiol 2016; 115:1521-32. [PMID: 26763779 DOI: 10.1152/jn.01037.2015] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 01/07/2016] [Indexed: 11/22/2022] Open
Abstract
As the major input to the basal ganglia, the striatum is innervated by a wide range of other areas. Overlapping input from these regions is speculated to influence temporal correlations among striatal ensembles. However, the network dynamics among behaviorally related neural populations in the striatum has not been extensively studied. We used large-scale neural recordings to monitor activity from striatal ensembles in mice undergoing Pavlovian reward conditioning. A subpopulation of putative medium spiny projection neurons (MSNs) was found to discriminate between cues that predicted the delivery of a reward and cues that predicted no specific outcome. These cells were preferentially located in lateral subregions of the striatum. Discriminating MSNs were more spontaneously active and more correlated than their nondiscriminating counterparts. Furthermore, discriminating fast spiking interneurons (FSIs) represented a highly prevalent group in the recordings, which formed a strongly correlated network with discriminating MSNs. Spike time cross-correlation analysis showed the existence of synchronized activity among FSIs and feedforward inhibitory modulation of MSN spiking by FSIs. These findings suggest that populations of functionally specialized (cue-discriminating) striatal neurons have distinct network dynamics that sets them apart from nondiscriminating cells, potentially to facilitate accurate behavioral responding during associative reward learning.
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Affiliation(s)
- Konstantin I Bakhurin
- Neuroscience Interdepartmental Program, University of California, Los Angeles, California
| | - Victor Mac
- Department of Neurobiology, University of California, Los Angeles, California
| | - Peyman Golshani
- Neuroscience Interdepartmental Program, University of California, Los Angeles, California; Department of Neurology, University of California, Los Angeles, California; Integrative Center for Learning and Memory, University of California, Los Angeles, California; West Los Angeles Veterans Affairs Medical Center, Los Angeles, California
| | - Sotiris C Masmanidis
- Neuroscience Interdepartmental Program, University of California, Los Angeles, California; Department of Neurobiology, University of California, Los Angeles, California; Integrative Center for Learning and Memory, University of California, Los Angeles, California; California NanoSystems Institute, University of California, Los Angeles, California; and
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15
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Role of input correlations in shaping the variability and noise correlations of evoked activity in the neocortex. J Neurosci 2015; 35:8611-25. [PMID: 26041927 DOI: 10.1523/jneurosci.4536-14.2015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Recent analysis of evoked activity recorded across different brain regions and tasks revealed a marked decrease in noise correlations and trial-by-trial variability. Given the importance of correlations and variability for information processing within the rate coding paradigm, several mechanisms have been proposed to explain the reduction in these quantities despite an increase in firing rates. These models suggest that anatomical clusters and/or tightly balanced excitation-inhibition can generate intrinsic network dynamics that may exhibit a reduction in noise correlations and trial-by-trial variability when perturbed by an external input. Such mechanisms based on the recurrent feedback crucially ignore the contribution of feedforward input to the statistics of the evoked activity. Therefore, we investigated how statistical properties of the feedforward input shape the statistics of the evoked activity. Specifically, we focused on the effect of input correlation structure on the noise correlations and trial-by-trial variability. We show that the ability of neurons to transfer the input firing rate, correlation, and variability to the output depends on the correlations within the presynaptic pool of a neuron, and that an input with even weak within-correlations can be sufficient to reduce noise correlations and trial-by-trial variability, without requiring any specific recurrent connectivity structure. In general, depending on the ongoing activity state, feedforward input could either increase or decrease noise correlation and trial-by-trial variability. Thus, we propose that evoked activity statistics are jointly determined by the feedforward and feedback inputs.
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16
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Bahuguna J, Aertsen A, Kumar A. Existence and control of Go/No-Go decision transition threshold in the striatum. PLoS Comput Biol 2015; 11:e1004233. [PMID: 25910230 PMCID: PMC4409064 DOI: 10.1371/journal.pcbi.1004233] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 03/11/2015] [Indexed: 11/19/2022] Open
Abstract
A typical Go/No-Go decision is suggested to be implemented in the brain via the activation of the direct or indirect pathway in the basal ganglia. Medium spiny neurons (MSNs) in the striatum, receiving input from cortex and projecting to the direct and indirect pathways express D1 and D2 type dopamine receptors, respectively. Recently, it has become clear that the two types of MSNs markedly differ in their mutual and recurrent connectivities as well as feedforward inhibition from FSIs. Therefore, to understand striatal function in action selection, it is of key importance to identify the role of the distinct connectivities within and between the two types of MSNs on the balance of their activity. Here, we used both a reduced firing rate model and numerical simulations of a spiking network model of the striatum to analyze the dynamic balance of spiking activities in D1 and D2 MSNs. We show that the asymmetric connectivity of the two types of MSNs renders the striatum into a threshold device, indicating the state of cortical input rates and correlations by the relative activity rates of D1 and D2 MSNs. Next, we describe how this striatal threshold can be effectively modulated by the activity of fast spiking interneurons, by the dopamine level, and by the activity of the GPe via pallidostriatal backprojections. We show that multiple mechanisms exist in the basal ganglia for biasing striatal output in favour of either the `Go' or the `No-Go' pathway. This new understanding of striatal network dynamics provides novel insights into the putative role of the striatum in various behavioral deficits in patients with Parkinson's disease, including increased reaction times, L-Dopa-induced dyskinesia, and deep brain stimulation-induced impulsivity.
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Affiliation(s)
- Jyotika Bahuguna
- Bernstein Center Freiburg and Faculty of Biology, University of Freiburg, Freiburg, Germany
- Computational Biology, School of Computer Science and Communication, KTH Royal Institute of Technology, Stockholm, Sweden
- * E-mail: (JB); (AK)
| | - Ad Aertsen
- Bernstein Center Freiburg and Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Arvind Kumar
- Bernstein Center Freiburg and Faculty of Biology, University of Freiburg, Freiburg, Germany
- Computational Biology, School of Computer Science and Communication, KTH Royal Institute of Technology, Stockholm, Sweden
- * E-mail: (JB); (AK)
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17
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Moyer JT, Halterman BL, Finkel LH, Wolf JA. Lateral and feedforward inhibition suppress asynchronous activity in a large, biophysically-detailed computational model of the striatal network. Front Comput Neurosci 2014; 8:152. [PMID: 25505406 PMCID: PMC4243567 DOI: 10.3389/fncom.2014.00152] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 11/04/2014] [Indexed: 12/03/2022] Open
Abstract
Striatal medium spiny neurons (MSNs) receive lateral inhibitory projections from other MSNs and feedforward inhibitory projections from fast-spiking, parvalbumin-containing striatal interneurons (FSIs). The functional roles of these connections are unknown, and difficult to study in an experimental preparation. We therefore investigated the functionality of both lateral (MSN-MSN) and feedforward (FSI-MSN) inhibition using a large-scale computational model of the striatal network. The model consists of 2744 MSNs comprised of 189 compartments each and 121 FSIs comprised of 148 compartments each, with dendrites explicitly represented and almost all known ionic currents included and strictly constrained by biological data as appropriate. Our analysis of the model indicates that both lateral inhibition and feedforward inhibition function at the population level to limit non-ensemble MSN spiking while preserving ensemble MSN spiking. Specifically, lateral inhibition enables large ensembles of MSNs firing synchronously to strongly suppress non-ensemble MSNs over a short time-scale (10–30 ms). Feedforward inhibition enables FSIs to strongly inhibit weakly activated, non-ensemble MSNs while moderately inhibiting activated ensemble MSNs. Importantly, FSIs appear to more effectively inhibit MSNs when FSIs fire asynchronously. Both types of inhibition would increase the signal-to-noise ratio of responding MSN ensembles and contribute to the formation and dissolution of MSN ensembles in the striatal network.
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Affiliation(s)
- Jason T Moyer
- Department of Bioengineering, University of Pennsylvania Philadelphia, PA, USA
| | | | - Leif H Finkel
- Department of Bioengineering, University of Pennsylvania Philadelphia, PA, USA
| | - John A Wolf
- Department of Neurosurgery, University of Pennsylvania Philadelphia, PA, USA
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18
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Yim MY, Kumar A, Aertsen A, Rotter S. Impact of correlated inputs to neurons: modeling observations from in vivo intracellular recordings. J Comput Neurosci 2014; 37:293-304. [PMID: 24789376 PMCID: PMC4159600 DOI: 10.1007/s10827-014-0502-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 04/02/2014] [Accepted: 04/04/2014] [Indexed: 11/24/2022]
Abstract
In vivo recordings in rat somatosensory cortex suggest that excitatory and inhibitory inputs are often correlated during spontaneous and sensory-evoked activity. Using a computational approach, we study how the interplay of input correlations and timing observed in experiments controls the spiking probability of single neurons. Several correlation-based mechanisms are identified, which can effectively switch a neuron on and off. In addition, we investigate the transfer of input correlation to output correlation in pairs of neurons, at the spike train and the membrane potential levels, by considering spike-driving and non-spike-driving inputs separately. In particular, we propose a plausible explanation for the in vivo finding that membrane potentials in neighboring neurons are correlated, but the spike-triggered averages of membrane potentials preceding a spike are not: Neighboring neurons possibly receive an ongoing bombardment of correlated subthreshold background inputs, and occasionally uncorrelated spike-driving inputs.
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Affiliation(s)
- Man Yi Yim
- Department of Mathematics, University of Hong Kong, Pokfulam Road, Hong Kong
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19
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Striatal disorders dissociate mechanisms of enhanced and impaired response selection - Evidence from cognitive neurophysiology and computational modelling. NEUROIMAGE-CLINICAL 2014; 4:623-34. [PMID: 24936413 PMCID: PMC4053645 DOI: 10.1016/j.nicl.2014.04.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Revised: 04/07/2014] [Accepted: 04/07/2014] [Indexed: 12/15/2022]
Abstract
Paradoxically enhanced cognitive processes in neurological disorders provide vital clues to understanding neural function. However, what determines whether the neurological damage is impairing or enhancing is unclear. Here we use the performance of patients with two disorders of the striatum to dissociate mechanisms underlying cognitive enhancement and impairment resulting from damage to the same system. In a two-choice decision task, Huntington's disease patients were faster and less error prone than controls, yet a patient with the rare condition of benign hereditary chorea (BHC) was both slower and more error prone. EEG recordings confirmed significant differences in neural processing between the groups. Analysis of a computational model revealed that the common loss of connectivity between striatal neurons in BHC and Huntington's disease impairs response selection, but the increased sensitivity of NMDA receptors in Huntington's disease potentially enhances response selection. Crucially the model shows that there is a critical threshold for increased sensitivity: below that threshold, impaired response selection results. Our data and model thus predict that specific striatal malfunctions can contribute to either impaired or enhanced selection, and provide clues to solving the paradox of how Huntington's disease can lead to both impaired and enhanced cognitive processes. Comparative study on well-defined neurological disorders Striatal disorders dissociate mechanisms of enhanced and impaired cognition. Neurophysiological data in patients is combined with computational modelling.
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Key Words
- AMPA, a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid
- BHC, benign hereditary chorea
- Basal ganglia
- Benign hereditary chorea
- Computational modelling
- EEG
- EEG, electroencephalography
- ERP, event related potential
- Executive control
- FSIs, fast spiking interneurons
- GABA, ?-aminobutyric acid
- Huntington's disease
- MMN, mismatch negativity
- MMSE, Mini Mental Status Examination
- MSN, medium spiny neuron
- NMDA, N-methyl-d-aspartate
- RON, reorientation of attention
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20
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Rădulescu A. Input statistics and Hebbian cross-talk effects. Neural Comput 2014; 26:654-92. [PMID: 24479779 DOI: 10.1162/neco_a_00565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
As an extension of prior work, we studied inspecific Hebbian learning using the classical Oja model. We used a combination of analytical tools and numerical simulations to investigate how the effects of synaptic cross talk (which we also refer to as synaptic inspecificity) depend on the input statistics. We investigated a variety of patterns that appear in dimensions higher than two (and classified them based on covariance type and input bias). We found that the effects of cross talk on learning dynamics and outcome is highly dependent on the input statistics and that cross talk may lead in some cases to catastrophic effects on learning or development. Arbitrarily small levels of cross talk are able to trigger bifurcations in learning dynamics, or bring the system in close enough proximity to a critical state, to make the effects indistinguishable from a real bifurcation. We also investigated how cross talk behaves toward unbiased ("competitive") inputs and in which circumstances it can help the system productively resolve the competition. Finally, we discuss the idea that sophisticated neocortical learning requires accurate synaptic updates (similar to polynucleotide copying, which requires highly accurate replication). Since it is unlikely that the brain can completely eliminate cross talk, we support the proposal that is uses a neural mechanism that "proofreads" the accuracy of the updates, much as DNA proofreading lowers copying error rate.
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Affiliation(s)
- Anca Rădulescu
- Department of Mathematics, University of Colorado, Boulder, CO 80309-0395, U.S.A.
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21
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Tomkins A, Vasilaki E, Beste C, Gurney K, Humphries MD. Transient and steady-state selection in the striatal microcircuit. Front Comput Neurosci 2014; 7:192. [PMID: 24478684 PMCID: PMC3895806 DOI: 10.3389/fncom.2013.00192] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 12/21/2013] [Indexed: 11/13/2022] Open
Abstract
Although the basal ganglia have been widely studied and implicated in signal processing and action selection, little information is known about the active role the striatal microcircuit plays in action selection in the basal ganglia-thalamo-cortical loops. To address this knowledge gap we use a large scale three dimensional spiking model of the striatum, combined with a rate coded model of the basal ganglia-thalamo-cortical loop, to asses the computational role the striatum plays in action selection. We identify a robust transient phenomena generated by the striatal microcircuit, which temporarily enhances the difference between two competing cortical inputs. We show that this transient is sufficient to modulate decision making in the basal ganglia-thalamo-cortical circuit. We also find that the transient selection originates from a novel adaptation effect in single striatal projection neurons, which is amenable to experimental testing. Finally, we compared transient selection with models implementing classical steady-state selection. We challenged both forms of model to account for recent reports of paradoxically enhanced response selection in Huntington's disease patients. We found that steady-state selection was uniformly impaired under all simulated Huntington's conditions, but transient selection was enhanced given a sufficient Huntington's-like increase in NMDA receptor sensitivity. Thus our models provide an intriguing hypothesis for the mechanisms underlying the paradoxical cognitive improvements in manifest Huntington's patients.
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Affiliation(s)
- Adam Tomkins
- Department of Computer Science, University of Sheffield Sheffield, UK ; INSIGNEO Institute for in Silico Medicine, University of Sheffield Sheffield, UK
| | - Eleni Vasilaki
- Department of Computer Science, University of Sheffield Sheffield, UK ; INSIGNEO Institute for in Silico Medicine, University of Sheffield Sheffield, UK
| | - Christian Beste
- Cognitive Neurophysiology, Universitätsklinikum Carl Gustav Carus TU Dresden, Germany
| | - Kevin Gurney
- Adaptive Behaviour Research Group, Department of Psychology, University of Sheffield Sheffield, UK
| | - Mark D Humphries
- Faculty of Life Sciences, University of Manchester Manchester, UK
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22
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Damodaran S, Evans RC, Blackwell KT. Synchronized firing of fast-spiking interneurons is critical to maintain balanced firing between direct and indirect pathway neurons of the striatum. J Neurophysiol 2013; 111:836-48. [PMID: 24304860 DOI: 10.1152/jn.00382.2013] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The inhibitory circuits of the striatum are known to be critical for motor function, yet their contributions to Parkinsonian motor deficits are not clear. Altered firing in the globus pallidus suggests that striatal medium spiny neurons (MSN) of the direct (D1 MSN) and indirect pathway (D2 MSN) are imbalanced during dopamine depletion. Both MSN classes receive inhibitory input from each other and from inhibitory interneurons within the striatum, specifically the fast-spiking interneurons (FSI). To investigate the role of inhibition in maintaining striatal balance, we developed a biologically-realistic striatal network model consisting of multicompartmental neuron models: 500 D1 MSNs, 500 D2 MSNs and 49 FSIs. The D1 and D2 MSN models are differentiated based on published experiments of individual channel modulations by dopamine, with D2 MSNs being more excitable than D1 MSNs. Despite this difference in response to current injection, in the network D1 and D2 MSNs fire at similar frequencies in response to excitatory synaptic input. Simulations further reveal that inhibition from FSIs connected by gap junctions is critical to produce balanced firing. Although gap junctions produce only a small increase in synchronization between FSIs, removing these connections resulted in significant firing differences between D1 and D2 MSNs, and balanced firing was restored by providing synchronized cortical input to the FSIs. Together these findings suggest that desynchronization of FSI firing is sufficient to alter balanced firing between D1 and D2 MSNs.
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Affiliation(s)
- Sriraman Damodaran
- The Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia
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Ponzi A, Wickens JR. Optimal balance of the striatal medium spiny neuron network. PLoS Comput Biol 2013; 9:e1002954. [PMID: 23592954 PMCID: PMC3623749 DOI: 10.1371/journal.pcbi.1002954] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 01/13/2013] [Indexed: 11/18/2022] Open
Abstract
Slowly varying activity in the striatum, the main Basal Ganglia input structure, is important for the learning and execution of movement sequences. Striatal medium spiny neurons (MSNs) form cell assemblies whose population firing rates vary coherently on slow behaviourally relevant timescales. It has been shown that such activity emerges in a model of a local MSN network but only at realistic connectivities of 10 ~ 20% and only when MSN generated inhibitory post-synaptic potentials (IPSPs) are realistically sized. Here we suggest a reason for this. We investigate how MSN network generated population activity interacts with temporally varying cortical driving activity, as would occur in a behavioural task. We find that at unrealistically high connectivity a stable winners-take-all type regime is found where network activity separates into fixed stimulus dependent regularly firing and quiescent components. In this regime only a small number of population firing rate components interact with cortical stimulus variations. Around 15% connectivity a transition to a more dynamically active regime occurs where all cells constantly switch between activity and quiescence. In this low connectivity regime, MSN population components wander randomly and here too are independent of variations in cortical driving. Only in the transition regime do weak changes in cortical driving interact with many population components so that sequential cell assemblies are reproducibly activated for many hundreds of milliseconds after stimulus onset and peri-stimulus time histograms display strong stimulus and temporal specificity. We show that, remarkably, this activity is maximized at striatally realistic connectivities and IPSP sizes. Thus, we suggest the local MSN network has optimal characteristics - it is neither too stable to respond in a dynamically complex temporally extended way to cortical variations, nor is it too unstable to respond in a consistent repeatable way. Rather, it is optimized to generate stimulus dependent activity patterns for long periods after variations in cortical excitation.
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Affiliation(s)
- Adam Ponzi
- Neurobiology Research Unit, Okinawa Institute of Science and Technology (OIST), Okinawa, Japan.
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25
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Ponzi A, Wickens J. Input dependent cell assembly dynamics in a model of the striatal medium spiny neuron network. Front Syst Neurosci 2012; 6:6. [PMID: 22438838 PMCID: PMC3306002 DOI: 10.3389/fnsys.2012.00006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 02/04/2012] [Indexed: 11/13/2022] Open
Abstract
The striatal medium spiny neuron (MSN) network is sparsely connected with fairly weak GABAergic collaterals receiving an excitatory glutamatergic cortical projection. Peri-stimulus time histograms (PSTH) of MSN population response investigated in various experimental studies display strong firing rate modulations distributed throughout behavioral task epochs. In previous work we have shown by numerical simulation that sparse random networks of inhibitory spiking neurons with characteristics appropriate for UP state MSNs form cell assemblies which fire together coherently in sequences on long behaviorally relevant timescales when the network receives a fixed pattern of constant input excitation. Here we first extend that model to the case where cortical excitation is composed of many independent noisy Poisson processes and demonstrate that cell assembly dynamics is still observed when the input is sufficiently weak. However if cortical excitation strength is increased more regularly firing and completely quiescent cells are found, which depend on the cortical stimulation. Subsequently we further extend previous work to consider what happens when the excitatory input varies as it would when the animal is engaged in behavior. We investigate how sudden switches in excitation interact with network generated patterned activity. We show that sequences of cell assembly activations can be locked to the excitatory input sequence and outline the range of parameters where this behavior is shown. Model cell population PSTH display both stimulus and temporal specificity, with large population firing rate modulations locked to elapsed time from task events. Thus the random network can generate a large diversity of temporally evolving stimulus dependent responses even though the input is fixed between switches. We suggest the MSN network is well suited to the generation of such slow coherent task dependent response which could be utilized by the animal in behavior.
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Affiliation(s)
- Adam Ponzi
- Neurobiology Research Unit, Okinawa Institute of Science and TechnologyOkinawa, Japan
| | - Jeff Wickens
- Neurobiology Research Unit, Okinawa Institute of Science and TechnologyOkinawa, Japan
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