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Guglietti B, Hobbs D, Collins-Praino LE. Optimizing Cognitive Training for the Treatment of Cognitive Dysfunction in Parkinson's Disease: Current Limitations and Future Directions. Front Aging Neurosci 2021; 13:709484. [PMID: 34720988 PMCID: PMC8549481 DOI: 10.3389/fnagi.2021.709484] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 08/17/2021] [Indexed: 01/09/2023] Open
Abstract
Cognitive dysfunction, primarily involving impairments in executive function, visuospatial function and memory, is one of the most common non-motor symptoms of Parkinson’s disease (PD). Currently, the only pharmacological treatments available for the treatment of cognitive dysfunction in PD provide variable benefit, making the search for potential non-pharmacological therapies to improve cognitive function of significant interest. One such therapeutic strategy may be cognitive training (CT), which involves the repetition of standardized tasks with the aim of improving specific aspects of cognition. Several studies have examined the effects of CT in individuals with PD and have shown benefits in a variety of cognitive domains, but the widespread use of CT in these individuals may be limited by motor impairments and other concerns in study design. Here, we discuss the current state of the literature on the use of CT for PD and propose recommendations for future implementation. We also explore the potential use of more recent integrative, adaptive and assistive technologies, such as virtual reality, which may optimize the delivery of CT in PD.
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Affiliation(s)
- Bianca Guglietti
- Cognition, Ageing and Neurodegenerative Disease Laboratory, Department of Medical Sciences, Adelaide Medical School, The University of Adelaide, Adelaide, SA, Australia
| | - David Hobbs
- Medical Device Research Institute, College of Science and Engineering, Flinders University, Tonsley, SA, Australia.,Allied Health & Human Performance, University of South Australia, Adelaide, SA, Australia
| | - Lyndsey E Collins-Praino
- Cognition, Ageing and Neurodegenerative Disease Laboratory, Department of Medical Sciences, Adelaide Medical School, The University of Adelaide, Adelaide, SA, Australia
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Betancur DFA, Tarragó MDGL, Torres ILDS, Fregni F, Caumo W. Central Post-Stroke Pain: An Integrative Review of Somatotopic Damage, Clinical Symptoms, and Neurophysiological Measures. Front Neurol 2021; 12:678198. [PMID: 34484097 PMCID: PMC8416310 DOI: 10.3389/fneur.2021.678198] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 07/02/2021] [Indexed: 01/26/2023] Open
Abstract
Introduction: The physiopathology of central post-stroke pain (CPSP) is poorly understood, which may contribute to the limitations of diagnostic and therapeutic advancements. Thus, the current systematic review was conducted to examine, from an integrated perspective, the cortical neurophysiological changes observed via transcranial magnetic stimulation (TMS), focusing on the structural damage, and clinical symptoms in patients with CPSP. Methods: The literature review included the databases EMBASE, PubMed, and ScienceDirect using the following search terms by MeSH or Entree descriptors: [("Cerebral Stroke") AND ("Pain" OR "Transcranial Magnetic Stimulation") AND ("Transcranial Magnetic Stimulation")] (through September 29, 2020). A total of 297 articles related to CPSP were identified. Of these, only four quantitatively recorded cortical measurements. Results: We found four studies with different methodologies and results of the TMS measures. According to the National Institutes of Health (NIH) guidelines, two studies had low methodological quality and the other two studies had satisfactory methodological quality. The four studies compared the motor threshold (MT) of the stroke-affected hemisphere with the unaffected hemisphere or with healthy controls. Two studies assessed other cortical excitability measures, such as cortical silent period (CSP), short-interval intracortical inhibition (SICI), and intracortical facilitation (ICF). The main limitations in the interpretation of the results were the heterogeneity in parameter measurements, unknown cortical excitability measures as potential prognostic markers, the lack of a control group without pain, and the absence of consistent and validated diagnosis criteria. Conclusion: Despite the limited number of studies that prevented us from conducting a meta-analysis, the dataset of this systematic review provides evidence to improve the understanding of CPSP physiopathology. Additionally, these studies support the construction of a framework for diagnosis and will help improve the methodological quality of future research in somatosensory sequelae following stroke. Furthermore, they offer a way to integrate dysfunctional neuroplasticity markers that are indirectly assessed by neurophysiological measures with their correlated clinical symptoms.
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Affiliation(s)
- Daniel Fernando Arias Betancur
- Graduate Program in Medical Sciences, School of Medicine, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Laboratory of Pain & Neuromodulation, Clinical Research Center, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil
| | | | - Iraci Lucena da Silva Torres
- Graduate Program in Medical Sciences, School of Medicine, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Pharmacology of Pain and Neuromodulation: Pre-clinical Investigations Research Group, Federal University of Rio Grande Do Sul (UFRGS), Porto Alegre, Brazil
| | - Felipe Fregni
- Laboratory of Neuromodulation and Center for Clinical Research Learning, Physics, and Rehabilitation Department, Spaulding Rehabilitation Hospital, Boston, MA, United States
| | - Wolnei Caumo
- Graduate Program in Medical Sciences, School of Medicine, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Laboratory of Pain & Neuromodulation, Clinical Research Center, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil
- Pain and Palliative Care Service, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil
- Department of Surgery, School of Medicine, Federal University of Rio Grande Do Sul (UFRGS), Porto Alegre, Brazil
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Braz BY, Belforte JE, Murer MG, Galiñanes GL. Properties of the corticostriatal long term depression induced by medial prefrontal cortex high frequency stimulation in vivo. Neuropharmacology 2017; 121:278-286. [DOI: 10.1016/j.neuropharm.2017.05.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 04/24/2017] [Accepted: 05/01/2017] [Indexed: 10/19/2022]
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Two-photon imaging of chronically implanted neural electrodes: Sealing methods and new insights. J Neurosci Methods 2015; 258:46-55. [PMID: 26526459 DOI: 10.1016/j.jneumeth.2015.10.007] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 10/12/2015] [Accepted: 10/15/2015] [Indexed: 01/03/2023]
Abstract
BACKGROUND Two-photon microscopy has enabled the visualization of dynamic tissue changes to injury and disease in vivo. While this technique has provided powerful new information, in vivo two-photon chronic imaging around tethered cortical implants, such as microelectrodes or neural probes, present unique challenges. NEW METHOD A number of strategies are described to prepare a cranial window to longitudinally observe the impact of neural probes on brain tissue and vasculature for up to 3 months. RESULTS It was found that silastic sealants limit cell infiltration into the craniotomy, thereby limiting light scattering and preserving window clarity over time. In contrast, low concentration hydrogel sealants failed to prevent cell infiltration and their use at high concentration displaced brain tissue and disrupted probe performance. COMPARISON WITH EXISTING METHOD(S) The use of silastic sealants allows for a suitable imaging window for long term chronic experiments and revealed new insights regarding the dynamic leukocyte response around implants and the nature of chronic BBB leakage in the sub-dural space. CONCLUSION The presented method provides a valuable tool for evaluating the chronic inflammatory response and the performance of emerging implantable neural technologies.
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Tozzi A, de Iure A, Tantucci M, Durante V, Quiroga-Varela A, Giampà C, Di Mauro M, Mazzocchetti P, Costa C, Di Filippo M, Grassi S, Pettorossi VE, Calabresi P. Endogenous 17β-estradiol is required for activity-dependent long-term potentiation in the striatum: interaction with the dopaminergic system. Front Cell Neurosci 2015; 9:192. [PMID: 26074768 PMCID: PMC4445326 DOI: 10.3389/fncel.2015.00192] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 04/30/2015] [Indexed: 11/13/2022] Open
Abstract
17β-estradiol (E2), a neurosteroid synthesized by P450-aromatase (ARO), modulates various brain functions. We characterized the role of the locally synthesized E2 on striatal long-term synaptic plasticity and explored possible interactions between E2 receptors (ERs) and dopamine (DA) receptors in the dorsal striatum of adult male rats. Inhibition of E2 synthesis or antagonism of ERs prevented the induction of long-term potentiation (LTP) in both medium spiny neurons (MSNs) and cholinergic interneurons (ChIs). Activation of a D1-like DA receptor/cAMP/PKA-dependent pathway restored LTP. In MSNs exogenous E2 reversed the effect of ARO inhibition. Also antagonism of M1 muscarinic receptors prevented the D1-like receptor-mediated restoration of LTP confirming a role for ChIs in controlling the E2-mediated LTP of MSNs. A novel striatal interaction, occurring between ERs and D1-like receptors in both MSNs and ChIs, might be critical to regulate basal ganglia physiology and to compensate synaptic alterations in Parkinson’s disease.
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Affiliation(s)
- Alessandro Tozzi
- Department of Experimental Medicine, Section of Physiology and Biochemistry, University of Perugia Perugia, Italy ; Fondazione Santa Lucia, IRCCS Rome, Italy
| | - Antonio de Iure
- Clinica Neurologica, Dipartimento di Medicina, Università degli Studi di Perugia, Ospedale Santa Maria della Misericordia Perugia, Italy
| | - Michela Tantucci
- Clinica Neurologica, Dipartimento di Medicina, Università degli Studi di Perugia, Ospedale Santa Maria della Misericordia Perugia, Italy
| | - Valentina Durante
- Clinica Neurologica, Dipartimento di Medicina, Università degli Studi di Perugia, Ospedale Santa Maria della Misericordia Perugia, Italy
| | - Ana Quiroga-Varela
- Clinica Neurologica, Dipartimento di Medicina, Università degli Studi di Perugia, Ospedale Santa Maria della Misericordia Perugia, Italy
| | | | - Michela Di Mauro
- Department of Experimental Medicine, Section of Physiology and Biochemistry, University of Perugia Perugia, Italy
| | - Petra Mazzocchetti
- Clinica Neurologica, Dipartimento di Medicina, Università degli Studi di Perugia, Ospedale Santa Maria della Misericordia Perugia, Italy
| | - Cinzia Costa
- Clinica Neurologica, Dipartimento di Medicina, Università degli Studi di Perugia, Ospedale Santa Maria della Misericordia Perugia, Italy
| | - Massimiliano Di Filippo
- Clinica Neurologica, Dipartimento di Medicina, Università degli Studi di Perugia, Ospedale Santa Maria della Misericordia Perugia, Italy
| | - Silvarosa Grassi
- Department of Experimental Medicine, Section of Physiology and Biochemistry, University of Perugia Perugia, Italy
| | - Vito Enrico Pettorossi
- Department of Experimental Medicine, Section of Physiology and Biochemistry, University of Perugia Perugia, Italy
| | - Paolo Calabresi
- Fondazione Santa Lucia, IRCCS Rome, Italy ; Clinica Neurologica, Dipartimento di Medicina, Università degli Studi di Perugia, Ospedale Santa Maria della Misericordia Perugia, Italy
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Kozai TDY, Du Z, Gugel ZV, Smith MA, Chase SM, Bodily LM, Caparosa EM, Friedlander RM, Cui XT. Comprehensive chronic laminar single-unit, multi-unit, and local field potential recording performance with planar single shank electrode arrays. J Neurosci Methods 2014; 242:15-40. [PMID: 25542351 DOI: 10.1016/j.jneumeth.2014.12.010] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 12/11/2014] [Accepted: 12/15/2014] [Indexed: 11/28/2022]
Abstract
BACKGROUND Intracortical electrode arrays that can record extracellular action potentials from small, targeted groups of neurons are critical for basic neuroscience research and emerging clinical applications. In general, these electrode devices suffer from reliability and variability issues, which have led to comparative studies of existing and emerging electrode designs to optimize performance. Comparisons of different chronic recording devices have been limited to single-unit (SU) activity and employed a bulk averaging approach treating brain architecture as homogeneous with respect to electrode distribution. NEW METHOD In this study, we optimize the methods and parameters to quantify evoked multi-unit (MU) and local field potential (LFP) recordings in eight mice visual cortices. RESULTS These findings quantify the large recording differences stemming from anatomical differences in depth and the layer dependent relative changes to SU and MU recording performance over 6-months. For example, performance metrics in Layer V and stratum pyramidale were initially higher than Layer II/III, but decrease more rapidly. On the other hand, Layer II/III maintained recording metrics longer. In addition, chronic changes at the level of layer IV are evaluated using visually evoked current source density. COMPARISON WITH EXISTING METHOD(S) The use of MU and LFP activity for evaluation and tracking biological depth provides a more comprehensive characterization of the electrophysiological performance landscape of microelectrodes. CONCLUSIONS A more extensive spatial and temporal insight into the chronic electrophysiological performance over time will help uncover the biological and mechanical failure mechanisms of the neural electrodes and direct future research toward the elucidation of design optimization for specific applications.
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Affiliation(s)
- Takashi D Y Kozai
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, United States; McGowan Institute for Regenerative Medicine, University of Pittsburgh, United States.
| | - Zhanhong Du
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, United States; McGowan Institute for Regenerative Medicine, University of Pittsburgh, United States
| | - Zhannetta V Gugel
- Bioengineering, University of Pittsburgh, United States; Division of Biology and Biological Engineering, California Institute of Technology, United States
| | - Matthew A Smith
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, United States; McGowan Institute for Regenerative Medicine, University of Pittsburgh, United States; Ophthalmology, University of Pittsburgh, United States
| | - Steven M Chase
- Center for the Neural Basis of Cognition, United States; Biomedical Engineering, Carnegie Mellon University, United States
| | - Lance M Bodily
- Neurological Surgery, University of Pittsburgh, United States
| | | | | | - X Tracy Cui
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, United States; McGowan Institute for Regenerative Medicine, University of Pittsburgh, United States
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Evans RC, Maniar YM, Blackwell KT. Dynamic modulation of spike timing-dependent calcium influx during corticostriatal upstates. J Neurophysiol 2013; 110:1631-45. [PMID: 23843436 DOI: 10.1152/jn.00232.2013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The striatum of the basal ganglia demonstrates distinctive upstate and downstate membrane potential oscillations during slow-wave sleep and under anesthetic. The upstates generate calcium transients in the dendrites, and the amplitude of these calcium transients depends strongly on the timing of the action potential (AP) within the upstate. Calcium is essential for synaptic plasticity in the striatum, and these large calcium transients during the upstates may control which synapses undergo plastic changes. To investigate the mechanisms that underlie the relationship between calcium and AP timing, we have developed a realistic biophysical model of a medium spiny neuron (MSN). We have implemented sophisticated calcium dynamics including calcium diffusion, buffering, and pump extrusion, which accurately replicate published data. Using this model, we found that either the slow inactivation of dendritic sodium channels (NaSI) or the calcium inactivation of voltage-gated calcium channels (CDI) can cause high calcium corresponding to early APs and lower calcium corresponding to later APs. We found that only CDI can account for the experimental observation that sensitivity to AP timing is dependent on NMDA receptors. Additional simulations demonstrated a mechanism by which MSNs can dynamically modulate their sensitivity to AP timing and show that sensitivity to specifically timed pre- and postsynaptic pairings (as in spike timing-dependent plasticity protocols) is altered by the timing of the pairing within the upstate. These findings have implications for synaptic plasticity in vivo during sleep when the upstate-downstate pattern is prominent in the striatum.
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Affiliation(s)
- R C Evans
- The Krasnow Institute for Advanced Studies, George Mason University, Fairfax, Virginia; and
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8
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Abstract
Corticostriatal projections are essential components of forebrain circuits and are widely involved in motivated behaviour. These axonal projections are formed by two distinct classes of cortical neurons, intratelencephalic (IT) and pyramidal tract (PT) neurons. Convergent evidence points to IT versus PT differentiation of the corticostriatal system at all levels of functional organization, from cellular signalling mechanisms to circuit topology. There is also growing evidence for IT/PT imbalance as an aetiological factor in neurodevelopmental, neuropsychiatric and movement disorders - autism, amyotrophic lateral sclerosis, obsessive-compulsive disorder, schizophrenia, Huntington's and Parkinson's diseases and major depression are highlighted here.
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Affiliation(s)
- Gordon M. G. Shepherd
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA;
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Galiñanes GL, Braz BY, Murer MG. Origin and properties of striatal local field potential responses to cortical stimulation: temporal regulation by fast inhibitory connections. PLoS One 2011; 6:e28473. [PMID: 22163020 PMCID: PMC3232222 DOI: 10.1371/journal.pone.0028473] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Accepted: 11/08/2011] [Indexed: 11/30/2022] Open
Abstract
Evoked striatal field potentials are seldom used to study corticostriatal communication in vivo because little is known about their origin and significance. Here we show that striatal field responses evoked by stimulating the prelimbic cortex in mice are reduced by more than 90% after infusing the AMPA receptor antagonist CNQX close to the recording electrode. Moreover, the amplitude of local field responses and dPSPs recorded in striatal medium spiny neurons increase in parallel with increasing stimulating current intensity. Finally, the evoked striatal fields show several of the basic known properties of corticostriatal transmission, including paired pulse facilitation and topographical organization. As a case study, we characterized the effect of local GABAA receptor blockade on striatal field and multiunitary action potential responses to prelimbic cortex stimulation. Striatal activity was recorded through a 24 channel silicon probe at about 600 µm from a microdialysis probe. Intrastriatal administration of the GABAA receptor antagonist bicuculline increased by 65±7% the duration of the evoked field responses. Moreover, the associated action potential responses were markedly enhanced during bicuculline infusion. Bicuculline enhancement took place at all the striatal sites that showed a response to cortical stimulation before drug infusion, but sites showing no field response before bicuculline remained unresponsive during GABAA receptor blockade. Thus, the data demonstrate that fast inhibitory connections exert a marked temporal regulation of input-output transformations within spatially delimited striatal networks responding to a cortical input. Overall, we propose that evoked striatal fields may be a useful tool to study corticostriatal synaptic connectivity in relation to behavior.
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Affiliation(s)
- Gregorio L Galiñanes
- Neural Circuit Physiology Lab, Systems Neuroscience Group, Department of Physiology and Biophysics, University of Buenos Aires School of Medicine, Buenos Aires, Argentina.
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10
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Abstract
The basal ganglia are a chain of subcortical nuclei that facilitate action selection. Two striatal projection systems--so-called direct and indirect pathways--form the functional backbone of the basal ganglia circuit. Twenty years ago, investigators proposed that the striatum's ability to use dopamine (DA) rise and fall to control action selection was due to the segregation of D(1) and D(2) DA receptors in direct- and indirect-pathway spiny projection neurons. Although this hypothesis sparked a debate, the evidence that has accumulated since then clearly supports this model. Recent advances in the means of marking neural circuits with optical or molecular reporters have revealed a clear-cut dichotomy between these two cell types at the molecular, anatomical, and physiological levels. The contrast provided by these studies has provided new insights into how the striatum responds to fluctuations in DA signaling and how diseases that alter this signaling change striatal function.
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Affiliation(s)
- Charles R Gerfen
- Laboratory of Systems Neuroscience, National Institute of Mental Health, Bethesda, Maryland 20892, USA.
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Surmeier DJ, Carrillo-Reid L, Bargas J. Dopaminergic modulation of striatal neurons, circuits, and assemblies. Neuroscience 2011; 198:3-18. [PMID: 21906660 DOI: 10.1016/j.neuroscience.2011.08.051] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2011] [Revised: 08/18/2011] [Accepted: 08/23/2011] [Indexed: 12/19/2022]
Abstract
In recent years, there has been a great deal of progress toward understanding the role of the striatum and dopamine in action selection. The advent of new animal models and the development of optical techniques for imaging and stimulating select neuronal populations have provided the means by which identified synapses, cells, and circuits can be reliably studied. This review attempts to summarize some of the key advances in this broad area, focusing on dopaminergic modulation of intrinsic excitability and synaptic plasticity in canonical microcircuits in the striatum as well as recent work suggesting that there are neuronal assemblies within the striatum devoted to particular types of computation and possibly action selection.
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Affiliation(s)
- D J Surmeier
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
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Lerner TN, Kreitzer AC. Neuromodulatory control of striatal plasticity and behavior. Curr Opin Neurobiol 2011; 21:322-7. [PMID: 21333525 DOI: 10.1016/j.conb.2011.01.005] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Accepted: 01/25/2011] [Indexed: 11/19/2022]
Abstract
Excitatory synapses onto projection neurons in the striatum, the input nucleus of the basal ganglia, play a key role in regulating basal ganglia circuit function and are a major site of long-term synaptic plasticity. Here, we review the mechanisms and regulation of both long-term potentiation and long-term depression at these synapses. In particular, we highlight the role that neuromodulators play in determining the strength and direction of plasticity, which ultimately shapes the balance of activity in basal ganglia circuits and regulates motor behavior.
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Affiliation(s)
- Talia N Lerner
- Gladstone Institute of Neurological Disease, San Francisco, CA, USA
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Shulz DE, Jacob V. Spike-timing-dependent plasticity in the intact brain: counteracting spurious spike coincidences. Front Synaptic Neurosci 2010; 2:137. [PMID: 21423523 PMCID: PMC3059664 DOI: 10.3389/fnsyn.2010.00137] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Accepted: 08/06/2010] [Indexed: 11/21/2022] Open
Abstract
A computationally rich algorithm of synaptic plasticity has been proposed based on the experimental observation that the sign and amplitude of the change in synaptic weight is dictated by the temporal order and temporal contiguity between pre- and postsynaptic activities. For more than a decade, this spike-timing-dependent plasticity (STDP) has been studied mainly in brain slices of different brain structures and cultured neurons. Although not yet compelling, evidences for the STDP rule in the intact brain, including primary sensory cortices, have been provided lastly. From insects to mammals, the presentation of precisely timed sensory inputs drives synaptic and functional plasticity in the intact central nervous system, with similar timing requirements than the in vitro defined STDP rule. The convergent evolution of this plasticity rule in species belonging to so distant phylogenic groups points to the efficiency of STDP, as a mechanism for modifying synaptic weights, as the basis of activity-dependent development, learning and memory. In spite of the ubiquity of STDP phenomena, a number of significant variations of the rule are observed in different structures, neuronal types and even synapses on the same neuron, as well as between in vitro and in vivo conditions. In addition, the state of the neuronal network, its ongoing activity and the activation of ascending neuromodulatory systems in different behavioral conditions have dramatic consequences on the expression of spike-timing-dependent synaptic plasticity, and should be further explored.
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Affiliation(s)
- Daniel E Shulz
- Unité de Neurosciences, Information et Complexité, Centre National de la Recherche Scientifique Gif sur Yvette, France
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Surmeier DJ, Shen W, Day M, Gertler T, Chan S, Tian X, Plotkin JL. The role of dopamine in modulating the structure and function of striatal circuits. PROGRESS IN BRAIN RESEARCH 2010; 183:149-67. [PMID: 20696319 DOI: 10.1016/s0079-6123(10)83008-0] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Dopamine (DA) is a key regulator of action selection and associative learning. The striatum has long been thought to be a major locus of DA action in this process. Although all striatal cell types express G protein-coupled receptors for DA, the effects of DA on principal medium spiny neurons (MSNs) understandably have received the most attention. In the two principal classes of MSN, DA receptor expression diverges, with striatonigral MSNs robustly expressing D(1) receptors and striatopallidal MSNs expressing D(2) receptors. In the last couple of years, our understanding of how these receptors and the intracellular signalling cascades that they couple to modulate dendritic physiology and synaptic plasticity has rapidly expanded, fuelled in large measure by the development of new optical and genetic tools. These tools also have enabled a rapid expansion of our understanding of the striatal adaptations in models of Parkinson's disease. This chapter highlights some of the major advances in these areas.
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Affiliation(s)
- D James Surmeier
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
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