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Correa A, Ponzi A, Calderón VM, Migliore R. Pathological cell assembly dynamics in a striatal MSN network model. Front Comput Neurosci 2024; 18:1410335. [PMID: 38903730 PMCID: PMC11188713 DOI: 10.3389/fncom.2024.1410335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Accepted: 05/15/2024] [Indexed: 06/22/2024] Open
Abstract
Under normal conditions the principal cells of the striatum, medium spiny neurons (MSNs), show structured cell assembly activity patterns which alternate sequentially over exceedingly long timescales of many minutes. It is important to understand this activity since it is characteristically disrupted in multiple pathologies, such as Parkinson's disease and dyskinesia, and thought to be caused by alterations in the MSN to MSN lateral inhibitory connections and in the strength and distribution of cortical excitation to MSNs. To understand how these long timescales arise we extended a previous network model of MSN cells to include synapses with short-term plasticity, with parameters taken from a recent detailed striatal connectome study. We first confirmed the presence of sequentially switching cell clusters using the non-linear dimensionality reduction technique, Uniform Manifold Approximation and Projection (UMAP). We found that the network could generate non-stationary activity patterns varying extremely slowly on the order of minutes under biologically realistic conditions. Next we used Simulation Based Inference (SBI) to train a deep net to map features of the MSN network generated cell assembly activity to MSN network parameters. We used the trained SBI model to estimate MSN network parameters from ex-vivo brain slice calcium imaging data. We found that best fit network parameters were very close to their physiologically observed values. On the other hand network parameters estimated from Parkinsonian, decorticated and dyskinetic ex-vivo slice preparations were different. Our work may provide a pipeline for diagnosis of basal ganglia pathology from spiking data as well as for the design pharmacological treatments.
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Affiliation(s)
- Astrid Correa
- Institute of Biophysics, National Research Council, Palermo, Italy
| | - Adam Ponzi
- Institute of Biophysics, National Research Council, Palermo, Italy
- Center for Human Nature, Artificial Intelligence, and Neuroscience, Hokkaido University, Sapporo, Japan
| | - Vladimir M. Calderón
- Department of Developmental Neurobiology and Neurophysiology, Neurobiology Institute, National Autonomous University of Mexico, Querétaro, Mexico
| | - Rosanna Migliore
- Institute of Biophysics, National Research Council, Palermo, Italy
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Wang Q, Wang Y, Liao FF, Zhou FM. Dopaminergic inhibition of the inwardly rectifying potassium current in direct pathway medium spiny neurons in normal and parkinsonian striatum. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.29.590632. [PMID: 38746264 PMCID: PMC11092482 DOI: 10.1101/2024.04.29.590632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Despite the profound behavioral effects of the striatal dopamine (DA) activity and the inwardly rectifying potassium channel ( Kir ) being a key determinant of striatal medium spiny neuron (MSN) activity that also profoundly affects behavior, previously reported DA regulations of Kir are conflicting and incompatible with MSN function in behavior. Here we show that in normal mice with an intact striatal DA system, the predominant effect of DA activation of D1Rs in D1-MSNs is to cause a modest depolarization and increase in input resistance by inhibiting Kir, thus moderately increasing the spike outputs from behavior-promoting D1-MSNs. In parkinsonian (DA-depleted) striatum, DA increases D1-MSN intrinsic excitability more strongly than in normal striatum, consequently strongly increasing D1-MSN spike firing that is behavior-promoting; this DA excitation of D1-MSNs is stronger when the DA depletion is more severe. The DA inhibition of Kir is occluded by the Kir blocker barium chloride (BaCl 2 ). In behaving parkinsonian mice, BaCl 2 microinjection into the dorsal striatum stimulates movement but occludes the motor stimulation of D1R agonism. Taken together, our results resolve the long-standing question about what D1R agonism does to D1-MSN excitability in normal and parkinsonian striatum and strongly indicate that D1R inhibition of Kir is a key ion channel mechanism that mediates D1R agonistic behavioral stimulation in normal and parkinsonian animals.
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Zhong M, Wang Y, Lin G, Liao FF, Zhou FM. Dopamine-independent development and maintenance of mouse striatal medium spiny neuron dendritic spines. Neurobiol Dis 2023; 181:106096. [PMID: 37001611 PMCID: PMC10864017 DOI: 10.1016/j.nbd.2023.106096] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 03/18/2023] [Accepted: 03/20/2023] [Indexed: 03/31/2023] Open
Abstract
Striatal medium spiny neurons (MSNs) and striatal dopamine (DA) innervation are profoundly important for brain function such as motor control and cognition. A widely accepted theory posits that striatal DA loss causes (or leads to) MSN dendritic atrophy. However, examination of the literature indicates that the data from Parkinson's disease (PD) patients and animal PD models were contradictory among studies and hard to interpret. Here we have re-examined the potential effects of DA activity on MSN morphology or lack thereof. We found that in 15-day, 4- and 12-month old Pitx3 null mutant mice that have severe DA denervation in the dorsal striatum while having substantial residual DA innervation in the ventral striatum, MSN dendrites and spine numbers were similar in dorsal and ventral striatum, and also similar to those in normal mice. In 15-day, 4- and 12-month old tyrosine hydroxylase knockout mice that cannot synthesize L-dopa and thus have no endogenous DA in the entire brain, MSN dendrites and spine numbers were also indistinguishable from age-matched wild-type (WT) mice. Furthermore, in adult WT mice, unilateral 6-OHDA lesion at 12 months of age caused an almost complete striatal DA denervation in the lesioned side, but MSN dendrites and spine numbers were similar in the lesioned and control sides. Taken together, our data indicate that in mice, the development and maintenance of MSN dendrites and spines are DA-independent such that DA depletion does not trigger MSN dendritic atrophy; our data also suggest that the reported MSN dendritic atrophy in PD may be a component of neurodegeneration in PD rather than a consequence of DA denervation.
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Affiliation(s)
- Manli Zhong
- College of Life and Health Sciences, Northeastern University, No.195, Chuangxin Road, Hunnan District, Shenyang 110169, China; Department of Pharmacology, Addiction Science and Toxicology, College of Medicine, University of Tennessee, Memphis, TN 38103, USA.
| | - Yuhan Wang
- Department of Pharmacology, Addiction Science and Toxicology, College of Medicine, University of Tennessee, Memphis, TN 38103, USA
| | - Geng Lin
- Teaching Center for Basic Medical Experiments, China Medical University, Shenyang 110122, China; Department of Pharmacology, Addiction Science and Toxicology, College of Medicine, University of Tennessee, Memphis, TN 38103, USA
| | - Francesca-Fang Liao
- Department of Pharmacology, Addiction Science and Toxicology, College of Medicine, University of Tennessee, Memphis, TN 38103, USA
| | - Fu-Ming Zhou
- Department of Pharmacology, Addiction Science and Toxicology, College of Medicine, University of Tennessee, Memphis, TN 38103, USA.
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Zhao G, Zhang D, Qiao D, Liu X. Exercise improves behavioral dysfunction and inhibits the spontaneous excitatory postsynaptic current of D2-medium spiny neurons. Front Aging Neurosci 2022; 14:1001256. [PMID: 36533169 PMCID: PMC9752814 DOI: 10.3389/fnagi.2022.1001256] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 11/15/2022] [Indexed: 10/17/2023] Open
Abstract
The abnormal function of striatal medium spiny neurons (MSNs) leads to the excitation-inhibition imbalance of the basal ganglia, which is an important pathogenic factor of Parkinson's disease (PD). Exercise improves the dysfunction of basal ganglia through neuroprotective and neuroreparative effects, which may be related to the functional changes of expresses D2 receptors MSNs (D2-MSNs). In this study, D2-Cre mice were selected as the research objects, the PD model was induced by unilateral injection of 6-hydroxydopamine (6-OHDA) in the striatum, and the 4-week treadmill training method was used for exercise intervention. Using optogenetics and behavioral tests, we determined that the average total movement distance of PD and PD + Ex groups was significantly lower than that of the Control group, while that of the PD + Ex and PD + Laser groups was significantly higher than that of the PD group, and the two intervention methods of exercise and optogenetic-stimulation of the D2-MSNs had basically similar effects on improving the autonomic behavior of PD mice. To further investigate the cellular mechanisms, whole-cell patch clamp recordings were carried out on D2-MSNs. We found that exercise decreased the frequency and amplitude of spontaneous excitatory postsynaptic current (sEPSC) and increased the paired-pulse radio of D2-MSNs while leaving basic electrophysiological properties of MSNs unaffected. Combined with behavioral improvement and enhanced D2R protein expression, our findings suggest the inhibited sEPSC of D2-MSNs may contribute to the behavioral improvement after exercise.
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Affiliation(s)
- Gang Zhao
- Physical Education College, Soochow University, Suzhou, China
- Physical Education and Sports College, Beijing Normal University, Beijing, China
| | - Danyu Zhang
- Physical Education and Sports College, Beijing Normal University, Beijing, China
| | - Decai Qiao
- Physical Education and Sports College, Beijing Normal University, Beijing, China
| | - Xiaoli Liu
- Physical Education and Sports College, Beijing Normal University, Beijing, China
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Burke DA, Alvarez VA. Serotonin receptors contribute to dopamine depression of lateral inhibition in the nucleus accumbens. Cell Rep 2022; 39:110795. [PMID: 35545050 PMCID: PMC9171783 DOI: 10.1016/j.celrep.2022.110795] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 01/09/2022] [Accepted: 04/15/2022] [Indexed: 11/30/2022] Open
Abstract
Dopamine modulation of nucleus accumbens (NAc) circuitry is central to theories of reward seeking and reinforcement learning. Despite decades of effort, the acute dopamine actions on the NAc microcircuitry remain puzzling. Here, we dissect out the direct actions of dopamine on lateral inhibition between medium spiny neurons (MSNs) in mouse brain slices and find that they are pathway specific. Dopamine potently depresses GABAergic transmission from presynaptic dopamine D2 receptor-expressing MSNs (D2-MSNs), whereas it potentiates transmission from presynaptic dopamine D1 receptor-expressing MSNs (D1-MSNs) onto other D1-MSNs. To our surprise, presynaptic D2 receptors mediate only half of the depression induced by endogenous and exogenous dopamine. Presynaptic serotonin 5-HT1B receptors are responsible for a significant component of dopamine-induced synaptic depression. This study clarifies the mechanistic understanding of dopamine actions in the NAc by showing pathway-specific modulation of lateral inhibition and involvement of D2 and 5-HT1B receptors in dopamine depression of D2-MSN synapses. Burke and Alvarez find that, in the nucleus accumbens, dopamine depresses or potentiates lateral inhibition between projection neurons, depending on the specific synapses isolated. Dopamine depression of D2-MSN GABA transmission involves activation of 5-HT1B receptors, suggesting that cross-talk between monoamines and receptors plays a role in accumbens circuit function.
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Affiliation(s)
- Dennis A Burke
- Laboratory on Neurobiology of Compulsive Behaviors, NIAAA, National Institutes of Health, Bethesda, MD 20892, USA; Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Veronica A Alvarez
- Laboratory on Neurobiology of Compulsive Behaviors, NIAAA, National Institutes of Health, Bethesda, MD 20892, USA; Intramural Research Program, NIDA, NIH, Baltimore, MD 21224, USA; Center on Compulsive Behaviors, National Institutes of Health, Bethesda, MD 20892, USA.
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Nelson AB, Girasole AE, Lee HY, Ptáček LJ, Kreitzer AC. Striatal Indirect Pathway Dysfunction Underlies Motor Deficits in a Mouse Model of Paroxysmal Dyskinesia. J Neurosci 2022; 42:2835-2848. [PMID: 35165171 PMCID: PMC8973425 DOI: 10.1523/jneurosci.1614-20.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 01/20/2022] [Accepted: 02/07/2022] [Indexed: 11/21/2022] Open
Abstract
Abnormal involuntary movements, or dyskinesias, are seen in many neurologic diseases, including disorders where the brain appears grossly normal. This observation suggests that alterations in neural activity or connectivity may underlie dyskinesias. One influential model proposes that involuntary movements are driven by an imbalance in the activity of striatal direct and indirect pathway neurons (dMSNs and iMSNs, respectively). Indeed, in some animal models, there is evidence that dMSN hyperactivity contributes to dyskinesia. Given the many diseases associated with dyskinesia, it is unclear whether these findings generalize to all forms. Here, we used male and female mice in a mouse model of paroxysmal nonkinesigenic dyskinesia (PNKD) to assess whether involuntary movements are related to aberrant activity in the striatal direct and indirect pathways. In this model, as in the human disorder PNKD, animals experience dyskinetic attacks in response to caffeine or alcohol. Using optically identified striatal single-unit recordings in freely moving PNKD mice, we found a loss of iMSN firing during dyskinesia bouts. Further, chemogenetic inhibition of iMSNs triggered dyskinetic episodes in PNKD mice. Finally, we found that these decreases in iMSN firing are likely because of aberrant endocannabinoid-mediated suppression of glutamatergic inputs. These data show that striatal iMSN dysfunction contributes to the etiology of dyskinesia in PNKD, and suggest that indirect pathway hypoactivity may be a key mechanism for the generation of involuntary movements in other disorders.SIGNIFICANCE STATEMENT Involuntary movements, or dyskinesias, are part of many inherited and acquired neurologic syndromes. There are few effective treatments, most of which have significant side effects. Better understanding of which cells and patterns of activity cause dyskinetic movements might inform the development of new neuromodulatory treatments. In this study, we used a mouse model of an inherited human form of paroxysmal dyskinesia in combination with cell type-specific tools to monitor and manipulate striatal activity. We were able to narrow in on a specific group of neurons that causes dyskinesia in this model, and found alterations in a well-known form of plasticity in this cell type, endocannabinoid-dependent synaptic LTD. These findings point to new areas for therapeutic development.
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Affiliation(s)
- Alexandra B Nelson
- UCSF Neuroscience Graduate Program
- Department of Neurology, UCSF
- Kavli Institute for Fundamental Neuroscience
- UCSF Weill Institute for Neurosciences
| | - Allison E Girasole
- UCSF Neuroscience Graduate Program
- Department of Neurology, UCSF
- Kavli Institute for Fundamental Neuroscience
- UCSF Weill Institute for Neurosciences
| | | | - Louis J Ptáček
- UCSF Neuroscience Graduate Program
- Department of Neurology, UCSF
- Kavli Institute for Fundamental Neuroscience
- UCSF Weill Institute for Neurosciences
| | - Anatol C Kreitzer
- UCSF Neuroscience Graduate Program
- Department of Neurology, UCSF
- Department of Physiology, UCSF
- Kavli Institute for Fundamental Neuroscience
- UCSF Weill Institute for Neurosciences
- The Gladstone Institutes, San Francisco, California 94158
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Ramírez-Jarquín UN, Sharma M, Shahani N, Li Y, Boregowda S, Subramaniam S. Rhes protein transits from neuron to neuron and facilitates mutant huntingtin spreading in the brain. SCIENCE ADVANCES 2022; 8:eabm3877. [PMID: 35319973 PMCID: PMC8942366 DOI: 10.1126/sciadv.abm3877] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 02/02/2022] [Indexed: 05/12/2023]
Abstract
Rhes (RASD2) is a thyroid hormone-induced gene that regulates striatal motor activity and promotes neurodegeneration in Huntington disease (HD) and tauopathy. Rhes moves and transports the HD protein, polyglutamine-expanded huntingtin (mHTT), via tunneling nanotube (TNT)-like membranous protrusions between cultured neurons. However, similar intercellular Rhes transportation in the intact brain was unknown. Here, we report that Rhes induces TNT-like protrusions in the striatal medium spiny neurons (MSNs) and transported between dopamine-1 receptor (D1R)-MSNs and D2R-MSNs of intact striatum and organotypic brain slices. Notably, mHTT is robustly transported within the striatum and from the striatum to the cortical areas in the brain, and Rhes deletion diminishes such transport. Moreover, Rhes moves to the cortical regions following restricted expression in the MSNs of the striatum. Thus, Rhes is a first striatum-enriched protein demonstrated to move and transport mHTT between neurons and brain regions, providing new insights into interneuronal protein transport in the brain.
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Affiliation(s)
| | - Manish Sharma
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Neelam Shahani
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Yuqing Li
- Department of Neurology, University of Florida, Gainesville, FL 32610, USA
| | - Siddaraju Boregowda
- Department of Molecular Medicine, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Srinivasa Subramaniam
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
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8
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Animal models of action control and cognitive dysfunction in Parkinson's disease. PROGRESS IN BRAIN RESEARCH 2022; 269:227-255. [PMID: 35248196 DOI: 10.1016/bs.pbr.2022.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Parkinson's disease (PD) has historically been considered a motor disorder induced by a loss of dopaminergic neurons in the substantia nigra pars compacta. More recently, it has been recognized to have significant non-motor symptoms, most prominently cognitive symptoms associated with a dysexecutive syndrome. It is common in the literature to see motor and cognitive symptoms treated separately and, indeed, there has been a general call for specialized treatment of the latter, particularly in the more severe cases of PD with mild cognitive impairment and dementia. Animal studies have similarly been developed to model the motor or non-motor symptoms. Nevertheless, considerable research has established that segregating consideration of cognition from the precursors to motor movement, particularly movement associated with goal-directed action, is difficult if not impossible. Indeed, on some contemporary views cognition is embodied in action control, something that is particularly prevalent in theory and evidence relating to the integration of goal-directed and habitual control processes. The current paper addresses these issues within the literature detailing animal models of cognitive dysfunction in PD and their neural and neurochemical bases. Generally, studies using animal models of PD provide some of the clearest evidence for the integration of these action control processes at multiple levels of analysis and imply that consideration of this integrative process may have significant benefits for developing new approaches to the treatment of PD.
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Scarduzio M, Hess EJ, Standaert DG, Eskow Jaunarajs KL. Striatal synaptic dysfunction in dystonia and levodopa-induced dyskinesia. Neurobiol Dis 2022; 166:105650. [DOI: 10.1016/j.nbd.2022.105650] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 01/22/2022] [Accepted: 01/24/2022] [Indexed: 12/16/2022] Open
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Elabi OF, Pass R, Sormonta I, Nolbrant S, Drummond N, Kirkeby A, Kunath T, Parmar M, Lane EL. Human Embryonic Stem Cell-Derived Dopaminergic Grafts Alleviate L-DOPA Induced Dyskinesia. JOURNAL OF PARKINSON'S DISEASE 2022; 12:1881-1896. [PMID: 35466951 DOI: 10.3233/jpd-212920] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
BACKGROUND First-in-human studies to test the efficacy and safety of human embryonic stem cells (hESC)-derived dopaminergic cells in the treatment of Parkinson's disease (PD) are imminent. Pre-clinical studies using hESC-derived dopamine neuron transplants in rat models have indicated that the benefits parallel those shown with fetal tissue but have thus far failed to consider how ongoing L-DOPA administration might impact on the graft. OBJECTIVE To determine whether L-DOPA impacts on survival and functional recovery following grafting of hESC-derived dopaminergic neurons. METHODS Unilateral 6-OHDA lesioned rats were administered with either saline or L-DOPA prior to, and for 18 weeks following surgical implantation of dopaminergic neural progenitors derived from RC17 hESCs according to two distinct protocols in independent laboratories. RESULTS Grafts from both protocols elicited reduction in amphetamine-induced rotations. Reduced L-DOPA-induced dyskinesia preceded the improvement in amphetamine-induced rotations. Furthermore, L-DOPA had no effect on overall survival (HuNu) or dopaminergic neuron content of the graft (TH positive cells) but did lead to an increase in the number of GIRK2 positive neurons. CONCLUSION Critically, we found that L-DOPA was not detrimental to graft function, potentially enhancing graft maturation and promoting an A9 phenotype. Early improvement of L-DOPA-induced dyskinesia suggests that grafts may support the handling of exogenously supplied dopamine earlier than improvements in amphetamine-induced behaviours indicate. Given that one of the protocols will be employed in the production of cells for the European STEM-PD clinical trial, this is vital information for the management of patients and achieving optimal outcomes following transplantation of hESC-derived grafts for PD.
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Affiliation(s)
- Osama F Elabi
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK
| | - Rachel Pass
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK
| | - Irene Sormonta
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK
| | - Sara Nolbrant
- Developmental and Regenerative Neurobiology, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Nicola Drummond
- Centre for Regenerative Medicine, Institute for Stem Cell Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Agnete Kirkeby
- Developmental and Regenerative Neurobiology, Department of Experimental Medical Science, Lund University, Lund, Sweden
- Department of Neuroscience and The Novo Nordisk Foundation Center for Stem Cell Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Tilo Kunath
- Centre for Regenerative Medicine, Institute for Stem Cell Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Malin Parmar
- Developmental and Regenerative Neurobiology, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Emma L Lane
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK
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Sugiyama K, Kuroiwa M, Shuto T, Ohnishi YN, Kawahara Y, Miyamoto Y, Fukuda T, Nishi A. Subregion-Specific Regulation of Dopamine D1 Receptor Signaling in the Striatum: Implication for L-DOPA-Induced Dyskinesia. J Neurosci 2021; 41:6388-6414. [PMID: 34131032 PMCID: PMC8318081 DOI: 10.1523/jneurosci.0373-21.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 06/02/2021] [Accepted: 06/07/2021] [Indexed: 11/21/2022] Open
Abstract
The striatum is the main structure of the basal ganglia. The striatum receives inputs from various cortical areas, and its subregions play distinct roles in motor and emotional functions. Recently, striatal maps based on corticostriatal connectivity and striosome-matrix compartmentalization were developed, and we were able to subdivide the striatum into seven subregions. Dopaminergic modulation of the excitability of medium spiny neurons (MSNs) is critical for striatal function. In this study, we investigated the functional properties of dopamine signaling in seven subregions of the striatum from male mice. By monitoring the phosphorylation of PKA substrates including DARPP-32 in mouse striatal slices, we identified two subregions with low D1 receptor signaling: the dorsolateral portion of the intermediate/rostral part (DL-IR) and the intermediate/caudal part (IC). Low D1 receptor signaling in the two subregions was maintained by phosphodiesterase (PDE)10A and muscarinic M4 receptors. In an animal model of 6-hydroxydopamine (6-OHDA)-induced hemi-parkinsonism, D1 receptor signaling was upregulated in almost all subregions including the DL-IR, but not in the IC. When L-DOPA-induced dyskinesia (LID) was developed, D1 receptor signaling in the IC was upregulated and correlated with the severity of LID. Our results suggest that the function of the striatum is maintained through the subregion-specific regulation of dopamine D1 receptor signaling and that the aberrant activation of D1 receptor signaling in the IC is involved in LID. Future studies focusing on D1 receptor signaling in the IC of the striatum will facilitate the development of novel therapeutics for LID.SIGNIFICANCE STATEMENT Recent progress in striatal mapping based on corticostriatal connectivity and striosome-matrix compartmentalization allowed us to subdivide the striatum into seven subregions. Analyses of D1 receptor signaling in the seven subregions identified two unique subregions with low D1 receptor signaling: the dorsolateral portion of the intermediate/rostral part (DL-IR) and the intermediate/caudal part (IC). Aberrant activation of D1 receptor signaling in the IC is involved in L-DOPA-induced dyskinesia (LID). Previous studies of LID have mainly focused on the DL-IR, but not on the IC of the striatum. Future studies to clarify aberrant D1 receptor signaling in the IC are required to develop novel therapeutics for LID.
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Affiliation(s)
- Keita Sugiyama
- Department of Pharmacology, Kurume University School of Medicine, Kurume, Fukuoka 830-0011, Japan
| | - Mahomi Kuroiwa
- Department of Pharmacology, Kurume University School of Medicine, Kurume, Fukuoka 830-0011, Japan
| | - Takahide Shuto
- Department of Pharmacology, Kurume University School of Medicine, Kurume, Fukuoka 830-0011, Japan
| | - Yoshinori N Ohnishi
- Department of Pharmacology, Kurume University School of Medicine, Kurume, Fukuoka 830-0011, Japan
| | - Yukie Kawahara
- Department of Pharmacology, Kurume University School of Medicine, Kurume, Fukuoka 830-0011, Japan
| | - Yuta Miyamoto
- Department of Anatomy and Neurobiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Kumamoto 860-8556, Japan
| | - Takaichi Fukuda
- Department of Anatomy and Neurobiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Kumamoto 860-8556, Japan
| | - Akinori Nishi
- Department of Pharmacology, Kurume University School of Medicine, Kurume, Fukuoka 830-0011, Japan
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12
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Guo M, Xiang T, Li M, Sun Y, Sun S, Chen D, Jia Q, Li Y, Yao X, Wang X, Zhang X, He F, Wang M. Effects of intrastriatal injection of the dopamine receptor agonist SKF38393 and quinpirole on locomotor behavior in hemiparkinsonism rats. Behav Brain Res 2021; 411:113339. [PMID: 33945831 DOI: 10.1016/j.bbr.2021.113339] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 04/29/2021] [Accepted: 04/29/2021] [Indexed: 12/27/2022]
Abstract
Dopamine (DA) in the striatum is essential to influence motor behavior and may lead to movement impairment in Parkinson's disease (PD). The present study examined the different functions of the DA D1 receptor (D1R) and DA D2 receptor (D2R) by intrastriatal injection of the D1R agonist SKF38393 and the D2R agonist quinpirole in 6-hydroxydopamine (6-OHDA)-lesioned and control rats. All rats separately underwent dose-response behavior testing for SKF38393 (0, 0.5, 1.0, and 1.5 μg/site) or quinpirole (0, 1.0, 2.0, and 3.0 μg/site) to determine the effects of the optimal modulating threshold dose. Two behavior assessment indices, the time of latency to fall and the number of steps on a rotating treadmill, were used as reliable readouts of motor stimulation variables for quantifying the motor effects of the drugs. The findings indicate that at threshold doses, SKF38393 (1.0 μg/site) and quinpirole (1.0 μg/site) produce a dose-dependent increase in locomotor activity compared to vehicle injection. The ameliorated behavioral responses to either SKF38393 or quinpirole in lesioned rats were greater than those in unlesioned control rats. Moreover, the dose-dependent increase in locomotor capacity for quinpirole was greater than that for SKF38393 in lesioned rats. These results can clarify several key issues related to DA receptors directly and may provide a basis for exploring the potential of future selective dopamine therapies for PD in humans.
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Affiliation(s)
- Mengnan Guo
- Key Laboratory of Animal Resistance Biology of Shandong Province, College of Life Science, Shandong Normal University, Jinan, People's Republic of China
| | - Tianyu Xiang
- Key Laboratory of Animal Resistance Biology of Shandong Province, College of Life Science, Shandong Normal University, Jinan, People's Republic of China
| | - Min Li
- Key Laboratory of Animal Resistance Biology of Shandong Province, College of Life Science, Shandong Normal University, Jinan, People's Republic of China
| | - Yue Sun
- Key Laboratory of Animal Resistance Biology of Shandong Province, College of Life Science, Shandong Normal University, Jinan, People's Republic of China
| | - Shuang Sun
- Key Laboratory of Animal Resistance Biology of Shandong Province, College of Life Science, Shandong Normal University, Jinan, People's Republic of China
| | - Dadian Chen
- Key Laboratory of Animal Resistance Biology of Shandong Province, College of Life Science, Shandong Normal University, Jinan, People's Republic of China
| | - Qingmei Jia
- Key Laboratory of Animal Resistance Biology of Shandong Province, College of Life Science, Shandong Normal University, Jinan, People's Republic of China
| | - Yuchuan Li
- Key Laboratory of Animal Resistance Biology of Shandong Province, College of Life Science, Shandong Normal University, Jinan, People's Republic of China
| | - Xiaomeng Yao
- School of Nursing Qilu Institute of Technology, Jinan, 250200, People's Republic of China
| | - Xiaojun Wang
- The First Hospital Affiliated With Shandong First Medicine University, Jinan, People's Republic of China
| | - Xiao Zhang
- School of Computer Science and Technology, Shandong Jianzhu University, Jinan, 250200, People's Republic of China
| | - Feng He
- Key Laboratory of Animal Resistance Biology of Shandong Province, College of Life Science, Shandong Normal University, Jinan, People's Republic of China.
| | - Min Wang
- Key Laboratory of Animal Resistance Biology of Shandong Province, College of Life Science, Shandong Normal University, Jinan, People's Republic of China.
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Patthy Á, Murai J, Hanics J, Pintér A, Zahola P, Hökfelt TGM, Harkany T, Alpár A. Neuropathology of the Brainstem to Mechanistically Understand and to Treat Alzheimer's Disease. J Clin Med 2021; 10:jcm10081555. [PMID: 33917176 PMCID: PMC8067882 DOI: 10.3390/jcm10081555] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/01/2021] [Accepted: 04/05/2021] [Indexed: 12/18/2022] Open
Abstract
Alzheimer’s disease (AD) is a devastating neurodegenerative disorder as yet without effective therapy. Symptoms of this disorder typically reflect cortical malfunction with local neurohistopathology, which biased investigators to search for focal triggers and molecular mechanisms. Cortex, however, receives massive afferents from caudal brain structures, which do not only convey specific information but powerfully tune ensemble activity. Moreover, there is evidence that the start of AD is subcortical. The brainstem harbors monoamine systems, which establish a dense innervation in both allo- and neocortex. Monoaminergic synapses can co-release neuropeptides either by precisely terminating on cortical neurons or, when being “en passant”, can instigate local volume transmission. Especially due to its early damage, malfunction of the ascending monoaminergic system emerges as an early sign and possible trigger of AD. This review summarizes the involvement and cascaded impairment of brainstem monoaminergic neurons in AD and discusses cellular mechanisms that lead to their dysfunction. We highlight the significance and therapeutic challenges of transmitter co-release in ascending activating system, describe the role and changes of local connections and distant afferents of brainstem nuclei in AD, and summon the rapidly increasing diagnostic window during the last few years.
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Affiliation(s)
- Ágoston Patthy
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
| | - János Murai
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
| | - János Hanics
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
- SE NAP Research Group of Experimental Neuroanatomy and Developmental Biology, Hungarian Academy of Sciences, H-1094 Budapest, Hungary
| | - Anna Pintér
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
| | - Péter Zahola
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
| | - Tomas G. M. Hökfelt
- Department of Neuroscience, Biomedicum 7D, Karolinska Institutet, 17165 Stockholm, Sweden; (T.G.M.H.); (T.H.)
| | - Tibor Harkany
- Department of Neuroscience, Biomedicum 7D, Karolinska Institutet, 17165 Stockholm, Sweden; (T.G.M.H.); (T.H.)
- Center for Brain Research, Department of Molecular Neurosciences, Medical University of Vienna, 1090 Vienna, Austria
| | - Alán Alpár
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
- SE NAP Research Group of Experimental Neuroanatomy and Developmental Biology, Hungarian Academy of Sciences, H-1094 Budapest, Hungary
- Correspondence:
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14
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Mori A. How do adenosine A 2A receptors regulate motor function? Parkinsonism Relat Disord 2020; 80 Suppl 1:S13-S20. [PMID: 33349575 DOI: 10.1016/j.parkreldis.2020.09.025] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/14/2020] [Accepted: 09/15/2020] [Indexed: 01/17/2023]
Abstract
Adenosine A2A receptor antagonism is a new therapeutic strategy in the symptomatic treatment of Parkinson's disease (PD). This review addresses how adenosine A2A receptors are involved with the control of motor function via the basal ganglia-thalamocortical circuit, and considers the anatomical localization and physiological function of the receptor, along with its ultrastructural localization in critical areas/neurons of the circuit. Based on this understanding of the functional significance of the adenosine A2A receptor in the basal ganglia, the mode of action of A2A receptor antagonists is explored in terms of the dynamic functioning of the basal ganglia and the activity of the internal circuits of the striatum in PD. Finally, the pathophysiological differences between the normal and PD states are examined to emphasize the importance of the adenosine A2A receptor.
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15
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Dopamine receptor cooperativity synergistically drives dyskinesia, motor behavior, and striatal GABA neurotransmission in hemiparkinsonian rats. Neuropharmacology 2020; 174:108138. [DOI: 10.1016/j.neuropharm.2020.108138] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/21/2020] [Accepted: 05/13/2020] [Indexed: 12/29/2022]
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16
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Zhang X, Mantas I, Fridjonsdottir E, Andrén PE, Chergui K, Svenningsson P. Deficits in Motor Performance, Neurotransmitters and Synaptic Plasticity in Elderly and Experimental Parkinsonian Mice Lacking GPR37. Front Aging Neurosci 2020; 12:84. [PMID: 32292338 PMCID: PMC7120535 DOI: 10.3389/fnagi.2020.00084] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 03/10/2020] [Indexed: 12/16/2022] Open
Abstract
Parkinson’s disease (PD) etiology is attributed to aging and the progressive neurodegeneration of dopamine (DA) neurons of substantia nigra pars compacta (SNc). GPR37 is an orphan G-protein Coupled Receptor (GPCR) that is linked to the juvenile form of PD. In addition, misfolded GPR37 has been found in Lewy bodies. However, properly folded GPR37 found at the cell membrane appears to exert neuroprotection. In the present study we investigated the role of GPR37 in motor deficits due to aging or toxin-induced experimental parkinsonism. Elderly GPR37 knock out (KO) mice displayed hypolocomotion and worse fine movement performance compared to their WT counterparts. Striatal slice electrophysiology reveiled that GPR37 KO mice show profound decrease in long term potentiation (LTP) formation which is accompanied by an alteration in glutamate receptor subunit content. GPR37 KO animals exposed to intrastriatal 6-hydroxydopamine (6-OHDA) show poorer score in the behavioral cylinder test and more loss of the DA transporter (DAT) in striatum. The GPR37 KO striata exhibit a significant increase in GABA which is aggravated after DA depletion. Our data indicate that GPR37 KO mice have DA neuron deficit, enhanced striatal GABA levels and deficient corticostriatal LTP. They also respond stronger to 6-OHDA-induced neurotoxicity. Taken together, the data indicate that properly functional GPR37 may counteract aging processes and parkinsonism.
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Affiliation(s)
- Xiaoqun Zhang
- Laboratory of Translational Neuropharmacology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Ioannis Mantas
- Laboratory of Translational Neuropharmacology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Elva Fridjonsdottir
- Medical Mass Spectrometry Imaging, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Per E Andrén
- Medical Mass Spectrometry Imaging, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden.,National Resource for Mass Spectrometry Imaging, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Karima Chergui
- Laboratory of Molecular Neurophysiology, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Per Svenningsson
- Laboratory of Translational Neuropharmacology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
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17
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TGF-β/Smad3 Signalling Modulates GABA Neurotransmission: Implications in Parkinson's Disease. Int J Mol Sci 2020; 21:ijms21020590. [PMID: 31963327 PMCID: PMC7013528 DOI: 10.3390/ijms21020590] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/13/2020] [Accepted: 01/14/2020] [Indexed: 12/12/2022] Open
Abstract
γ-Aminobutiryc acid (GABA) is found extensively in different brain nuclei, including parts involved in Parkinson’s disease (PD), such as the basal ganglia and hippocampus. In PD and in different models of the disorder, an increase in GABA neurotransmission is observed and may promote bradykinesia or L-Dopa-induced side-effects. In addition, proteins involved in GABAA receptor (GABAAR) trafficking, such as GABARAP, Trak1 or PAELR, may participate in the aetiology of the disease. TGF-β/Smad3 signalling has been associated with several pathological features of PD, such as dopaminergic neurodegeneration; reduction of dopaminergic axons and dendrites; and α-synuclein aggregation. Moreover, TGF-β/Smad3 intracellular signalling was recently shown to modulate GABA neurotransmission in the context of parkinsonism and cognitive alterations. This review provides a summary of GABA neurotransmission and TGF-β signalling; their implications in PD; and the regulation of GABA neurotransmission by TGF-β/Smad3. There appear to be new possibilities to develop therapeutic approaches for the treatment of PD using GABA modulators.
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18
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Zhou J, Wu B, Lin X, Dai Y, Li T, Zheng W, Guo W, Vakal S, Chen X, Chen JF. Accumbal Adenosine A 2A Receptors Enhance Cognitive Flexibility by Facilitating Strategy Shifting. Front Cell Neurosci 2019; 13:130. [PMID: 31031594 PMCID: PMC6470273 DOI: 10.3389/fncel.2019.00130] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Accepted: 03/14/2019] [Indexed: 12/16/2022] Open
Abstract
The deficits of cognitive flexibility (including attentional set-shifting and reversal learning) concomitant with dysfunction of the striatum are observed in several neuropsychiatric disorders. Rodent and human studies have identified the striatum [particularly the dorsomedial striatum (DMS) and nucleus accumbens (NAc)] as the critical locus for control of cognitive flexibility, but the effective neuromodulator and pharmacological control of cognitive flexibility remains to be determined. The adenosine A2A receptors (A2ARs) are highly enriched in the striatopallidal neurons where they integrate dopamine and glutamate signals to modulate several cognitive behaviors, but their contribution to cognitive flexibility control is unclear. In this study, by coupling an automated operant cognitive flexibility task with striatal subregional knockdown (KD) of the A2AR via the Cre-loxP strategy, we demonstrated that NAc A2AR KD improved cognitive flexibility with enhanced attentional set-shifting and reversal learning by decreasing regressive and perseverative errors, respectively. This facilitation was not attributed to mnemonic process or motor activity as NAc A2AR KD did not affect the visual discrimination, lever-pressing acquisition, and locomotor activity, but was associated with increased attention and motivation as evident by the progressive ratio test (PRT). In contrast to NAc A2ARs, DMS A2ARs KD neither affected visual discrimination nor improved set-shifting nor reversal learning, but promoted the effort-related motivation. Thus, NAc and DMS A2ARs exert dissociable controls of cognitive flexibility with NAc A2ARs KD selectively enhancing cognitive flexibility by facilitating strategy shifting with increased motivation/attention.
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Affiliation(s)
- Jianhong Zhou
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
- State Key Laboratory of Optometry & Vision Science, Wenzhou, China
| | - Beibei Wu
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
- State Key Laboratory of Optometry & Vision Science, Wenzhou, China
| | - Xiangxiang Lin
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
- State Key Laboratory of Optometry & Vision Science, Wenzhou, China
| | - Yuwei Dai
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
- State Key Laboratory of Optometry & Vision Science, Wenzhou, China
| | - Tingting Li
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
- State Key Laboratory of Optometry & Vision Science, Wenzhou, China
| | - Wu Zheng
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
- State Key Laboratory of Optometry & Vision Science, Wenzhou, China
| | - Wei Guo
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
- State Key Laboratory of Optometry & Vision Science, Wenzhou, China
| | - Sergii Vakal
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Xingjun Chen
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
- State Key Laboratory of Optometry & Vision Science, Wenzhou, China
| | - Jiang-Fan Chen
- Molecular Neuropharmacology Laboratory, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
- State Key Laboratory of Optometry & Vision Science, Wenzhou, China
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19
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cAMP-producing chemogenetic and adenosine A2a receptor activation inhibits the inwardly rectifying potassium current in striatal projection neurons. Neuropharmacology 2019; 148:229-243. [PMID: 30659840 DOI: 10.1016/j.neuropharm.2019.01.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 01/14/2019] [Accepted: 01/14/2019] [Indexed: 12/29/2022]
Abstract
Adenosine A2a receptors (A2aRs) are highly and selectively expressed in D2-medium spiny neurons (D2-MSNs) that also express a high level of dopamine D2 receptors (D2Rs). However, it was not established how A2aR activity affects D2-MSN excitability, let alone the ion channels involved. We have performed two sets of experiments to determine the potential A2aR agonistic effects on D2-MSN intrinsic excitability and the underlying ion channel mechanism. First, we have used the cAMP-producing, Gαs/olf coupled designer receptors exclusively activated by designer drug (Gs-DREADDs) to phenocopy cAMP-stimulating A2aR activation. We found that activation of Gs-DREADD inhibited the inwardly rectifying potassium current (Kir)-a key regulator of MSN excitability, caused a depolarization, increased input resistance, and substantially increased the intrinsic excitability of MSNs such that depolarizing inputs evoked many more action potentials. Second, we have determined that A2aR agonism produced these same excitatory effects on D2-MSN intrinsic excitability and spike firing, although at lower magnitudes than those induced by Gs-DREADD activation; furthermore, these A2aR-triggered excitatory effects were intact in the presence of a D2R antagonist. Taken together, these results clearly establish that in striatal D2-MSNs, A2aR activation can independently inhibit Kir and increase intrinsic excitability and spike and neurotransmitter output; our results also indicate that Gs-DREADD can serve as a broadly useful positive control for neurotransmitter receptors that increase intracellular cAMP levels and hence facilitate the determination of the cellular effects of these neurotransmitter receptors.
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20
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Sagot B, Li L, Zhou FM. Hyperactive Response of Direct Pathway Striatal Projection Neurons to L-dopa and D1 Agonism in Freely Moving Parkinsonian Mice. Front Neural Circuits 2018; 12:57. [PMID: 30104963 PMCID: PMC6077202 DOI: 10.3389/fncir.2018.00057] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 05/03/2018] [Indexed: 01/02/2023] Open
Abstract
Dopamine (DA) profoundly stimulates motor function as demonstrated by the hypokinetic motor symptoms in Parkinson's disease (PD) and by the hyperkinetic motor side effects during dopaminergic treatment of PD. Dopamine (DA) receptor-bypassing, optogenetics- and chemogenetics-induced spike firing of striatal DA D1 receptor (D1R)-expressing, direct pathway medium spiny neurons (dSPNs or dMSNs) promotes movements. However, the endogenous D1R-mediated effects, let alone those of DA replacement, on dSPN spike activity in freely-moving animals is not established. Here we show that using transcription factor Pitx3 null mutant (Pitx3Null) mice as a model for severe and consistent DA denervation in the dorsal striatum in Parkinson's disease, antidromically identified striatonigral neurons (D1R-expressing dSPNs) had a lower baseline spike firing rate than that in DA-intact normal mice, and these neurons increased their spike firing more strongly in Pitx3Null mice than in WT mice in response to injection of L-dopa or the D1R agonist, SKF81297; the increase in spike firing temporally coincided with the motor-stimulating effects of L-dopa and SKF81297. Taken together, these results provide the first evidence from freely moving animals that in parkinsonian striatum, identified behavior-promoting dSPNs become hyperactive upon the administration of L-dopa or a D1 agonist, likely contributing to the profound dopaminergic motor stimulation in parkinsonian animals and PD patients.
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Affiliation(s)
- Ben Sagot
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Li Li
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Fu-Ming Zhou
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, United States
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21
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Bouabid S, Zhou FM. Cyclic AMP-producing chemogenetic activation of indirect pathway striatal projection neurons and the downstream effects on the globus pallidus and subthalamic nucleus in freely moving mice. J Neurochem 2018; 145:436-448. [PMID: 29500819 DOI: 10.1111/jnc.14331] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 02/19/2018] [Accepted: 02/26/2018] [Indexed: 01/11/2023]
Abstract
The indirect pathway striatal medium spiny projection neurons (iMSNs) are critical to motor and cognitive brain functions. These neurons express a high level of cAMP-increasing adenosine A2a receptors. However, the potential effects of cAMP production on iMSN spiking activity have not been established, and recording identified iMSNs in freely moving animals is challenging. Here, we show that in the transgenic mice expressing cAMP-producing G protein Gs -coupled designer receptor exclusively activated by designer drug (Gs-DREADD) in iMSNs, the baseline spike firing in MSNs is normal, indicating DREADD expression does not affect the normal physiology of these neurons. Intraperitoneal injection of the DREADD agonist clozapine-N-oxide (CNO; 2.5 mg/kg) increased the spike firing in 50% of the recorded MSNs. However, CNO did not affect MSN firing in Gs-DREADD-negative mice. We also found that CNO injection inhibited the spike firing of globus pallidus external segment (GPe) neurons in Gs-DREADD-positive mice, further indicating CNO excitation of iMSNs. Temporally coincident with these effects on spiking firing in the indirect pathway, CNO injection selectively inhibited locomotion in D2 Gs-DREADD mice. Taken together, our results strongly suggest that cAMP production in iMSNs can increase iMSN spiking activity and cause motor inhibition, thus addressing a long-standing question about the cellular functions of the cAMP-producing adenosine A2a receptors in iMSNs. Cover Image for this issue: doi: 10.1111/jnc.14181.
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Affiliation(s)
- Safa Bouabid
- Department of Pharmacology, University of Tennessee College of Medicine, Memphis, Tennessee, USA
| | - Fu-Ming Zhou
- Department of Pharmacology, University of Tennessee College of Medicine, Memphis, Tennessee, USA
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22
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Wang Y, Zhou FM. Striatal But Not Extrastriatal Dopamine Receptors Are Critical to Dopaminergic Motor Stimulation. Front Pharmacol 2017; 8:935. [PMID: 29311936 PMCID: PMC5742616 DOI: 10.3389/fphar.2017.00935] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Accepted: 12/11/2017] [Indexed: 11/19/2022] Open
Abstract
Dopamine (DA) is required for motor function in vertebrate animals including humans. The striatum, a key motor control center, receives a dense DA innervation and express high levels of DA D1 receptors (D1Rs) and D2 receptors (D2Rs). Other brain areas involved in motor function such as the globus pallidus external segment (GPe) and the substantia nigra pars reticulata (SNr) and the motor cortex (MC) also receive DA innervation and express DA receptors. Thus, the relative contribution of the striatal and extrastriatal DA systems to the motor function has been an important question critical for understanding the functional operation of the motor control circuits and also for therapeutic targeting. We have now experimentally addressed this question in the transcription factor Pitx3 null mutant (Pitx3Null) mice that have an autogenic and parkinsonian-like striatal DA denervation and hence supersensitive motor response to DA stimulation. Using DA agonist unilateral microinjection-induced rotation as a reliable readout of motor stimulation, our results show that L-dopa microinjection into the dorsal striatum (DS) induced 5–10 times more rotations than that induced by L-dopa microinjection into GPe and SNr, while L-dopa microinjection into the primary MC induced the least number of rotations. Furthermore, our results show that separate microinjection of the D1R-like agonist SKF81297 and the D2R-like agonist ropinirole into the DS each induced only modest numbers of rotation, whereas concurrent injection of the two agonists triggered more rotations than the sum of the rotations induced by each of these two agonists separately, indicating D1R–D2R synergy. These results suggest that the striatum, not GPe, SNr or MC, is the primary site for D1Rs and D2Rs to synergistically stimulate motor function in L-dopa treatment of Parkinson’s disease (PD). Our results also predict that non-selective, broad spectrum DA agonists activating both D1Rs and D2Rs are more efficacious anti-PD drugs than the current D2R agonists.
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Affiliation(s)
- Yuhan Wang
- Department of Pharmacology, University of Tennessee College of Medicine, Memphis, TN, United States
| | - Fu-Ming Zhou
- Department of Pharmacology, University of Tennessee College of Medicine, Memphis, TN, United States
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23
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Goto S. Striatal Gα olf/cAMP Signal-Dependent Mechanism to Generate Levodopa-Induced Dyskinesia in Parkinson's Disease. Front Cell Neurosci 2017; 11:364. [PMID: 29201000 PMCID: PMC5696598 DOI: 10.3389/fncel.2017.00364] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 11/06/2017] [Indexed: 11/24/2022] Open
Abstract
The motor symptoms of Parkinson’s disease (PD) result from striatal dopamine (DA) deficiency due to a progressive degeneration of nigral dopaminergic cells. Although DA replacement therapy is the mainstay to treat parkinsonian symptoms, a long-term daily administration of levodopa often develops levodopa-induced dyskinesia (LID). LID is closely linked to the dysregulation of cyclic adenosine monophosphate (cAMP) signaling cascades in the medium spiny neurons (MSNs), the principal neurons of the striatum, which are roughly halved with striatonigral MSNs by striatopallidal MSNs. The olfactory type G-protein α subunit (Gαolf) represents an important regulator of the cAMP signal activities in the striatum, where it positively couples with D1-type dopamine receptor (D1R) and adenosine A2A receptor (A2AR) to increase cAMP production in the MSNs. Notably, D1Rs are primarily expressed in striatonigral MSNs, whereas D2Rs and A2ARs are expressed in striatopallidal MSNs. Based on the evidence obtained from parkinsonian mice, we hypothesized that in the DA-denervated striatum with D1R hypersensitivity, a repeated and pulsatile exposure to levodopa might cause a usage-induced degradation of Gαolf proteins in striatal MSNs, resulting in increased and decreased levels of Gαolf protein in the striatonigral and striatopallidal MSNs, respectively. As a principal cause for generating LID, this might lead to an increased responsiveness to levodopa exposure in both striatonigral and striatopallidal MSNs. Our hypothesis reinforces the long-standing concept that LID might result from the reduced activity of the striatopallidal pathway and has important clinical implications.
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Affiliation(s)
- Satoshi Goto
- Department of Neurodegenerative Disorders Research, Institute of Biomedical Sciences, Graduate School of Medical Sciences, Tokushima University, Tokushima, Japan.,Parkinson's Disease and Dystonia Research Center, Tokushima University Hospital, Tokushima, Japan
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24
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Hou L, Chen W, Liu X, Qiao D, Zhou FM. Exercise-Induced Neuroprotection of the Nigrostriatal Dopamine System in Parkinson's Disease. Front Aging Neurosci 2017; 9:358. [PMID: 29163139 PMCID: PMC5675869 DOI: 10.3389/fnagi.2017.00358] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 10/19/2017] [Indexed: 12/11/2022] Open
Abstract
Epidemiological studies indicate that physical activity and exercise may reduce the risk of developing Parkinson's disease (PD), and clinical observations suggest that physical exercise can reduce the motor symptoms in PD patients. In experimental animals, a profound observation is that exercise of appropriate timing, duration, and intensity can reduce toxin-induced lesion of the nigrostriatal dopamine (DA) system in animal PD models, although negative results have also been reported, potentially due to inappropriate timing and intensity of the exercise regimen. Exercise may also minimize DA denervation-induced medium spiny neuron (MSN) dendritic atrophy and other abnormalities such as enlarged corticostriatal synapse and abnormal MSN excitability and spiking activity. Taken together, epidemiological studies, clinical observations, and animal research indicate that appropriately dosed physical activity and exercise may not only reduce the risk of developing PD in vulnerable populations but also benefit PD patients by potentially protecting the residual DA neurons or directly restoring the dysfunctional cortico-basal ganglia motor control circuit, and these benefits may be mediated by exercise-triggered production of endogenous neuroprotective molecules such as neurotrophic factors. Thus, exercise is a universally available, side effect-free medicine that should be prescribed to vulnerable populations as a preventive measure and to PD patients as a component of treatment. Future research needs to establish standardized exercise protocols that can reliably induce DA neuron protection, enabling the delineation of the underlying cellular and molecular mechanisms that in turn can maximize exercise-induced neuroprotection and neurorestoration in animal PD models and eventually in PD patients.
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Affiliation(s)
- Lijuan Hou
- Exercise Physiology Laboratory, College of Physical Education and Sports, Beijing Normal University, Beijing, China
| | - Wei Chen
- Exercise Physiology Laboratory, College of Physical Education and Sports, Beijing Normal University, Beijing, China.,Department of Exercise and Rehabilitation, Physical Education College, Hebei Normal University, Shijiazhuang, China
| | - Xiaoli Liu
- Exercise Physiology Laboratory, College of Physical Education and Sports, Beijing Normal University, Beijing, China
| | - Decai Qiao
- Exercise Physiology Laboratory, College of Physical Education and Sports, Beijing Normal University, Beijing, China
| | - Fu-Ming Zhou
- Department of Pharmacology, University of Tennessee College of Medicine, Memphis, TN, United States
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Zhai S, Tanimura A, Graves SM, Shen W, Surmeier DJ. Striatal synapses, circuits, and Parkinson's disease. Curr Opin Neurobiol 2017; 48:9-16. [PMID: 28843800 DOI: 10.1016/j.conb.2017.08.004] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 08/03/2017] [Indexed: 11/30/2022]
Abstract
The striatum is a hub in the basal ganglia circuitry controlling goal directed actions and habits. The loss of its dopaminergic (DAergic) innervation in Parkinson's disease (PD) disrupts the ability of the two principal striatal projection systems to respond appropriately to cortical and thalamic signals, resulting in the hypokinetic features of the disease. New tools to study brain circuitry have led to significant advances in our understanding of striatal circuits and how they adapt in PD models. This short review summarizes some of these recent studies and the gaps that remain to be filled.
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Affiliation(s)
- Shenyu Zhai
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Asami Tanimura
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Steven M Graves
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Weixing Shen
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - D James Surmeier
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
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