1
|
Salvatore MF. Dopamine Signaling in Substantia Nigra and Its Impact on Locomotor Function-Not a New Concept, but Neglected Reality. Int J Mol Sci 2024; 25:1131. [PMID: 38256204 PMCID: PMC10815979 DOI: 10.3390/ijms25021131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 01/11/2024] [Accepted: 01/13/2024] [Indexed: 01/24/2024] Open
Abstract
The mechanistic influences of dopamine (DA) signaling and impact on motor function are nearly always interpreted from changes in nigrostriatal neuron terminals in striatum. This is a standard practice in studies of human Parkinson's disease (PD) and aging and related animal models of PD and aging-related parkinsonism. However, despite dozens of studies indicating an ambiguous relationship between changes in striatal DA signaling and motor phenotype, this perseverating focus on striatum continues. Although DA release in substantia nigra (SN) was first reported almost 50 years ago, assessment of nigral DA signaling changes in relation to motor function is rarely considered. Whereas DA signaling has been well-characterized in striatum at all five steps of neurotransmission (biosynthesis and turnover, storage, release, reuptake, and post-synaptic binding) in the nigrostriatal pathway, the depth of such interrogations in the SN, outside of cell counts, is sparse. However, there is sufficient evidence that these steps in DA neurotransmission in the SN are operational and regulated autonomously from striatum and are present in human PD and aging and related animal models. To complete our understanding of how nigrostriatal DA signaling affects motor function, it is past time to include interrogation of nigral DA signaling. This brief review highlights evidence that changes in nigral DA signaling at each step in DA neurotransmission are autonomous from those in striatum and changes in the SN alone can influence locomotor function. Accordingly, for full characterization of how nigrostriatal DA signaling affects locomotor activity, interrogation of DA signaling in SN is essential.
Collapse
Affiliation(s)
- Michael F Salvatore
- Department of Pharmacology & Neuroscience, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
| |
Collapse
|
2
|
Delignat-Lavaud B, Ducrot C, Kouwenhoven W, Feller N, Trudeau LÉ. Implication of synaptotagmins 4 and 7 in activity-dependent somatodendritic dopamine release in the ventral midbrain. Open Biol 2022; 12:210339. [PMID: 35232250 PMCID: PMC8889187 DOI: 10.1098/rsob.210339] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 01/31/2022] [Indexed: 01/07/2023] Open
Abstract
Dopamine (DA) neurons can release DA not just from axon terminals, but also from their somatodendritic (STD) compartment through a mechanism that is still incompletely understood. Using voltammetry in mouse mesencephalic brain slices, we find that STD DA release has low capacity and shows a calcium sensitivity that is comparable to that of axonal release. We find that the molecular mechanism of STD DA release differs from axonal release with regard to the implication of synaptotagmin (Syt) calcium sensors. While individual constitutive knockout of Syt4 or Syt7 is not sufficient to reduce STD DA release, the removal of both isoforms reduces this release by approximately 50%, leaving axonal release unimpaired. Our work unveils clear differences in the mechanisms of STD and axonal DA release.
Collapse
Affiliation(s)
- Benoît Delignat-Lavaud
- Department of Pharmacology and Physiology, Université de Montréal, QC, Canada H3T 1J4
- Department of Neurosciences, Faculty of Medicine, Université de Montréal, QC, Canada H3T 1J4
- Neural Signaling and Circuitry Research Group (SNC), Montréal, QC, Canada H3C 3J7
| | - Charles Ducrot
- Department of Pharmacology and Physiology, Université de Montréal, QC, Canada H3T 1J4
- Department of Neurosciences, Faculty of Medicine, Université de Montréal, QC, Canada H3T 1J4
- Neural Signaling and Circuitry Research Group (SNC), Montréal, QC, Canada H3C 3J7
| | - Willemieke Kouwenhoven
- Department of Pharmacology and Physiology, Université de Montréal, QC, Canada H3T 1J4
- Department of Neurosciences, Faculty of Medicine, Université de Montréal, QC, Canada H3T 1J4
- Neural Signaling and Circuitry Research Group (SNC), Montréal, QC, Canada H3C 3J7
| | - Nina Feller
- Department of Pharmacology and Physiology, Université de Montréal, QC, Canada H3T 1J4
- Department of Neurosciences, Faculty of Medicine, Université de Montréal, QC, Canada H3T 1J4
- Neural Signaling and Circuitry Research Group (SNC), Montréal, QC, Canada H3C 3J7
| | - Louis-Éric Trudeau
- Department of Pharmacology and Physiology, Université de Montréal, QC, Canada H3T 1J4
- Department of Neurosciences, Faculty of Medicine, Université de Montréal, QC, Canada H3T 1J4
- Neural Signaling and Circuitry Research Group (SNC), Montréal, QC, Canada H3C 3J7
| |
Collapse
|
3
|
Labouesse MA, Cola RB, Patriarchi T. GPCR-Based Dopamine Sensors-A Detailed Guide to Inform Sensor Choice for In vivo Imaging. Int J Mol Sci 2020; 21:E8048. [PMID: 33126757 PMCID: PMC7672611 DOI: 10.3390/ijms21218048] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 09/25/2020] [Accepted: 09/26/2020] [Indexed: 12/12/2022] Open
Abstract
Understanding how dopamine (DA) encodes behavior depends on technologies that can reliably monitor DA release in freely-behaving animals. Recently, red and green genetically encoded sensors for DA (dLight, GRAB-DA) were developed and now provide the ability to track release dynamics at a subsecond resolution, with submicromolar affinity and high molecular specificity. Combined with rapid developments in in vivo imaging, these sensors have the potential to transform the field of DA sensing and DA-based drug discovery. When implementing these tools in the laboratory, it is important to consider there is not a 'one-size-fits-all' sensor. Sensor properties, most importantly their affinity and dynamic range, must be carefully chosen to match local DA levels. Molecular specificity, sensor kinetics, spectral properties, brightness, sensor scaffold and pharmacology can further influence sensor choice depending on the experimental question. In this review, we use DA as an example; we briefly summarize old and new techniques to monitor DA release, including DA biosensors. We then outline a map of DA heterogeneity across the brain and provide a guide for optimal sensor choice and implementation based on local DA levels and other experimental parameters. Altogether this review should act as a tool to guide DA sensor choice for end-users.
Collapse
Affiliation(s)
- Marie A. Labouesse
- Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA;
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA
| | - Reto B. Cola
- Anatomy and Program in Neuroscience, University of Fribourg, 1700 Fribourg, Switzerland;
- Institute of Pharmacology and Toxicology, University of Zurich, 8057 Zurich, Switzerland
| | - Tommaso Patriarchi
- Institute of Pharmacology and Toxicology, University of Zurich, 8057 Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, 8057 Zurich, Switzerland
| |
Collapse
|
4
|
Alarcón-Arís D, Pavia-Collado R, Miquel-Rio L, Coppola-Segovia V, Ferrés-Coy A, Ruiz-Bronchal E, Galofré M, Paz V, Campa L, Revilla R, Montefeltro A, Kordower JH, Vila M, Artigas F, Bortolozzi A. Anti-α-synuclein ASO delivered to monoamine neurons prevents α-synuclein accumulation in a Parkinson's disease-like mouse model and in monkeys. EBioMedicine 2020; 59:102944. [PMID: 32810825 PMCID: PMC7452525 DOI: 10.1016/j.ebiom.2020.102944] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 07/22/2020] [Accepted: 07/22/2020] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Progressive neuronal death in monoaminergic nuclei and widespread accumulation of α-synuclein are neuropathological hallmarks of Parkinson's disease (PD). Given that α-synuclein may be an early mediator of the pathological cascade that ultimately leads to neurodegeneration, decreased α-synuclein synthesis will abate neurotoxicity if delivered to the key affected neurons. METHODS We used a non-viral gene therapy based on a new indatraline-conjugated antisense oligonucleotide (IND-ASO) to disrupt the α-synuclein mRNA transcription selectively in monoamine neurons of a PD-like mouse model and elderly nonhuman primates. Molecular, cell biology, histological, neurochemical and behavioral assays were performed. FINDINGS Intracerebroventricular and intranasal IND-ASO administration for four weeks in a mouse model with AAV-mediated wild-type human α-synuclein overexpression in dopamine neurons prevented the synthesis and accumulation of α-synuclein in the connected brain regions, improving dopamine neurotransmission. Likewise, the four-week IND-ASO treatment led to decreased levels of endogenous α-synuclein protein in the midbrain monoamine nuclei of nonhuman primates, which are affected early in PD. CONCLUSIONS The inhibition of α-synuclein production in dopamine neurons and its accumulation in cortical/striatal projection areas may alleviate the early deficits of dopamine function, showing the high translational value of antisense oligonucleotides as a disease modifying therapy for PD and related synucleinopathies. FUNDING Grants SAF2016-75797-R, RTC-2014-2812-1 and RTC-2015-3309-1, Ministry of Economy and Competitiveness (MINECO) and European Regional Development Fund (ERDF), UE; Grant ID 9238, Michael J. Fox Foundation; and Centres for Networked Biomedical Research on Mental Health (CIBERSAM), and on Neurodegenerative Diseases (CIBERNED).
Collapse
Affiliation(s)
- Diana Alarcón-Arís
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Spanish National Research Council (CSIC), Barcelona, Spain; Institut d'Investigacions August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Rubén Pavia-Collado
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Spanish National Research Council (CSIC), Barcelona, Spain; Institut d'Investigacions August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Lluis Miquel-Rio
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Spanish National Research Council (CSIC), Barcelona, Spain; Institut d'Investigacions August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISCIII, Madrid, Spain
| | - Valentín Coppola-Segovia
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Spanish National Research Council (CSIC), Barcelona, Spain; Laboratory of Neurobiology and Redox Pathology, Department of Basic Pathology, Federal University of Paraná (UFPR), Curitiba, Brazil
| | - Albert Ferrés-Coy
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Spanish National Research Council (CSIC), Barcelona, Spain; Institut d'Investigacions August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISCIII, Madrid, Spain
| | - Esther Ruiz-Bronchal
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Spanish National Research Council (CSIC), Barcelona, Spain; Institut d'Investigacions August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISCIII, Madrid, Spain
| | - Mireia Galofré
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Spanish National Research Council (CSIC), Barcelona, Spain; Institut d'Investigacions August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Verónica Paz
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Spanish National Research Council (CSIC), Barcelona, Spain; Institut d'Investigacions August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISCIII, Madrid, Spain
| | - Leticia Campa
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Spanish National Research Council (CSIC), Barcelona, Spain; Institut d'Investigacions August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISCIII, Madrid, Spain
| | | | | | - Jeffrey H Kordower
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - Miquel Vila
- Neurodegenerative Diseases Research Group, Vall d'Hebron Research Institute, Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Madrid, Spain; Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
| | - Francesc Artigas
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Spanish National Research Council (CSIC), Barcelona, Spain; Institut d'Investigacions August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISCIII, Madrid, Spain
| | - Analia Bortolozzi
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB), Spanish National Research Council (CSIC), Barcelona, Spain; Institut d'Investigacions August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISCIII, Madrid, Spain.
| |
Collapse
|
5
|
Grieb ZA, Vitale EM, Morrell JI, Lonstein JS, Pereira M. Decreased mesolimbic dopaminergic signaling underlies the waning of maternal caregiving across the postpartum period in rats. Psychopharmacology (Berl) 2020; 237:1107-1119. [PMID: 31927604 DOI: 10.1007/s00213-019-05441-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 12/27/2019] [Indexed: 12/26/2022]
Abstract
RATIONALE Mesolimbic dopamine (DA) signaling is essential for the high maternal caregiving characteristic of the early postpartum period, but little is known about dopamine's role in the expression of maternal caregiving thereafter. OBJECTIVES We tested the hypothesis that decreased mesolimbic dopaminergic signaling is particularly responsible for the natural decline in maternal caregiving that occurs as the postpartum period progresses. METHODS Sprague-Dawley (SD) mother rats received intraperitoneal injections of either vehicle, the DA D1 receptor agonist SKF38393, the DA D2 receptor agonist quinpirole, or both agonists twice daily from postpartum days 9 to 15. In a separate experiment involving Long-Evans (LE) rats, we examined whether DA D1 and D2 receptor mRNAs in the nucleus accumbens (NA) shell and ventral tegmental area (VTA), along with DA turnover in the VTA, decline across the postpartum period in parallel with the decreasing maternal behavior. RESULTS All drug treatments significantly maintained higher frequencies of active maternal behaviors (nesting, pup licking, retrieval) compared to vehicle. Furthermore, the majority of mothers treated with SKF38393 either alone or combined with quinpirole maintained full expression of maternal behavior during behavioral testing. D2 receptor mRNA levels were found to be lower in the late postpartum NA shell and VTA compared to early postpartum, but D1 receptor mRNA levels in the NA shell were higher in the late postpartum period. Furthermore, both late postpartum and recently parturient LE mothers had higher VTA DA turnover compared to nulliparae, suggesting changes in mesolimbic signal-to-noise ratio both at the end and beginning of motherhood. CONCLUSIONS Collectively, our results suggest that alterations in mesolimbic DA is part of the neural substrate responsible for dynamic maternal caregiving across the entire postpartum period.
Collapse
Affiliation(s)
- Zachary A Grieb
- Neuroscience Program, Michigan State University, 108 Giltner Hall, East Lansing, MI, 48824, USA. .,Neuroscience Institute, Georgia State University, 880 Petit Science Center, Atlanta, GA, 30303, USA.
| | - Erika M Vitale
- Department of Psychology, Behavioral Neuroscience Program, Michigan State University, 316 Physics Rd, East Lansing, MI, 48824, USA
| | - Joan I Morrell
- Center for Molecular and Behavioral Neuroscience, Rutgers University, 197 University Avenue, Newark, NJ, 07102, USA
| | - Joseph S Lonstein
- Neuroscience Program, Michigan State University, 108 Giltner Hall, East Lansing, MI, 48824, USA.,Department of Psychology, Behavioral Neuroscience Program, Michigan State University, 316 Physics Rd, East Lansing, MI, 48824, USA
| | - Mariana Pereira
- Center for Molecular and Behavioral Neuroscience, Rutgers University, 197 University Avenue, Newark, NJ, 07102, USA.,Department of Psychological and Brain Sciences, University of Massachusetts, 535 Tobin Hall, Amherst, MA, 01003, USA
| |
Collapse
|
6
|
Effects of NBI-98782, a selective vesicular monoamine transporter 2 (VMAT2) inhibitor, on neurotransmitter efflux and phencyclidine-induced locomotor activity: Relevance to tardive dyskinesia and antipsychotic action. Pharmacol Biochem Behav 2020; 190:172872. [PMID: 32084491 DOI: 10.1016/j.pbb.2020.172872] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 01/24/2020] [Accepted: 02/15/2020] [Indexed: 01/31/2023]
Abstract
Valbenazine, a vesicular monoamine transporter 2 (VMAT2, SLC18A2) inhibitor, is a newly approved treatment for tardive dyskinesia. VMAT2 is present in the membrane of secretory vesicles and transports dopamine (DA), norepinephrine (NE), serotonin (5-HT), histamine, glutamate (Glu), and GABA into vesicles for presynaptic release. We utilized microdialysis in awake, freely moving mice to determine the effect of NBI-98782, the active metabolite of valbenazine, alone, or in combination with several antipsychotic drugs (APDs), to influence neurotransmitter efflux in the medial prefrontal cortex (mPFC), dorsal striatum (dSTR), hippocampus and nucleus accumbens (NAC); we also compared it with tetrabenazine, the prototypical VMAT2 inhibitor. Acute NBI-98782 and tetrabenazine decreased mPFC, dSTR, hippocampus, and NAC DA, 5-HT, and NE efflux, while increasing that of DOPAC, HVA, and 5-HIAA. Sub-chronic NBI-98782 (7 days) decreased baseline DA and 5-HT efflux in both mPFC and dSTR. NBI-98782 elicited similar effects on neurotransmitter efflux in sub-chronic NBI-98782-treated mice but also enhanced ACh and GABA; the decrease in DA efflux in mPFC and dSTR was not significant in the sc-treated animals. NBI-98782 suppressed clozapine-, olanzapine- and risperidone-induced DA efflux in both mPFC and dSTR, and ACh efflux in mPFC. NBI-98782 suppressed the haloperidol-induced DA efflux in dSTR, with minimal effect on GABA efflux. NBI-98782 attenuated PCP-induced DA, 5-HT, NE and Glu efflux, and AMPH-induced DA and NE efflux, in both mPFC and dSTR, as well as PCP- and AMPH-induced hyperlocomotion, suggesting possible beneficial antipsychotic effects.
Collapse
|
7
|
Blockade of the dopaminergic neurotransmission with AMPT and reserpine induces a differential expression of genes of the dopaminergic phenotype in substantia nigra. Neuropharmacology 2019; 166:107920. [PMID: 31870855 DOI: 10.1016/j.neuropharm.2019.107920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 11/28/2019] [Accepted: 12/20/2019] [Indexed: 11/23/2022]
Abstract
Dopaminergic neurons have the ability to release Dopamine from their axons as well as from their soma and dendrites. This somatodendritically-released Dopamine induces an autoinhibition of Dopaminergic neurons mediated by D2 autoreceptors, and the stimulation of neighbor GABAergic neurons mediated by D1 receptors (D1r). Here, our results suggest that the somatodendritic release of Dopamine in the substantia nigra (SN) may stimulate GABAergic neurons that project their axons into the hippocampus. Using semiquantitative multiplex RT-PCR we show that chronic blockade of the Dopaminergic neurotransmission with both AMPT and reserpine specifically decreases the expression levels of D1r, remarkably this may be the result of an antagonistic effect between AMPT and reserpine, as they induced the expression of a different set of genes when treated by separate. Furthermore, using anterograde and retrograde tracing techniques, we found that the GABAergic neurons that express D1r also project their axons in to the CA1 region of the hippocampus. Finally, we also found that the same treatment that decreases the expression levels of D1r in SN, also induces an impairment in the performance in an appetitive learning task that requires the coding of reward as well as navigational skills. Overall, our findings show the presence of a GABAergic interconnection between the SNr and the hippocampus mediated by D1r.
Collapse
|
8
|
Kasanga EA, Owens CL, Cantu MA, Richard AD, Davis RW, McDivitt LM, Blancher B, Pruett BS, Tan C, Gajewski A, Manfredsson FP, Nejtek VA, Salvatore MF. GFR-α1 Expression in Substantia Nigra Increases Bilaterally Following Unilateral Striatal GDNF in Aged Rats and Attenuates Nigral Tyrosine Hydroxylase Loss Following 6-OHDA Nigrostriatal Lesion. ACS Chem Neurosci 2019; 10:4237-4249. [PMID: 31538765 DOI: 10.1021/acschemneuro.9b00291] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Glial cell line-derived neurotrophic factor (GDNF) improved motor function in Parkinson's disease (PD) patients in Phase I clinical trials, and these effects persisted months after GDNF discontinuation. Conversely, phase II clinical trials reported no significant effects on motor improvement vs placebo. The disease duration and the quantity, infusion approach, and duration of GDNF delivery may affect GDNF efficacy in PD treatment. However, identifying mechanisms activated by GDNF that affect nigrostriatal function may reveal additional avenues to partially restore nigrostriatal function. In PD and aging models, GDNF affects tyrosine hydroxylase (TH) expression or phosphorylation in substantia nigra (SN), long after a single GDNF injection in striatum. In aged rats, the GDNF family receptor, GFR-α1, increases TH expression and phosphorylation in SN. To determine if GFR-α1 could be a mechanistic link in long-term GDNF impact, we conducted two studies; first to determine if a single unilateral striatal delivery of GDNF affected GFR-α1 and TH over time (1 day, 1 week, and 4 weeks) in the striatum or SN in aged rats, and second, to determine if soluble GFR-α1 could mitigate TH loss following 6-hydroxydopamine (6-OHDA) lesion. In aged rats, GDNF bilaterally increased ser31 TH phosphorylation and GFR-α1 expression in SN at 1 day and 4 weeks after GDNF, respectively. In striatum, GFR-α1 expression decreased 1 week after GDNF, only on the GDNF-injected side. In 6-OHDA-lesioned rats, recombinant soluble GFR-α1 mitigated nigral, but not striatal, TH protein loss following 6-OHDA. Together, these results show GDNF has immediate and long-term impact on dopamine regulation in the SN, which includes a gradual increase in GFR-α1 expression that may sustain TH expression and dopamine function therein.
Collapse
Affiliation(s)
- Ella A Kasanga
- Institute for Healthy Aging , University of North Texas Health Science Center , Fort Worth , Texas 76107 , United States
| | - Catherine L Owens
- Department of Pharmacology, Toxicology, & Neuroscience , Louisiana State University Health Sciences Center , Shreveport , Louisiana 71130 , United States
| | - Mark A Cantu
- Institute for Healthy Aging , University of North Texas Health Science Center , Fort Worth , Texas 76107 , United States
| | - Adam D Richard
- Department of Pharmacology, Toxicology, & Neuroscience , Louisiana State University Health Sciences Center , Shreveport , Louisiana 71130 , United States
| | - Richard W Davis
- Department of Pharmacology, Toxicology, & Neuroscience , Louisiana State University Health Sciences Center , Shreveport , Louisiana 71130 , United States
| | - Lisa M McDivitt
- Department of Pharmacology, Toxicology, & Neuroscience , Louisiana State University Health Sciences Center , Shreveport , Louisiana 71130 , United States
| | - Blake Blancher
- Department of Pharmacology, Toxicology, & Neuroscience , Louisiana State University Health Sciences Center , Shreveport , Louisiana 71130 , United States
| | - Brandon S Pruett
- Department of Pharmacology, Toxicology, & Neuroscience , Louisiana State University Health Sciences Center , Shreveport , Louisiana 71130 , United States
| | - Christopher Tan
- Institute for Healthy Aging , University of North Texas Health Science Center , Fort Worth , Texas 76107 , United States
| | - Austin Gajewski
- Institute for Healthy Aging , University of North Texas Health Science Center , Fort Worth , Texas 76107 , United States
| | - Fredric P Manfredsson
- Parkinson's Disease Research Unit, Department of Neurobiology , Barrow Neurological Institute , Phoenix , Arizona 85013 , United States
| | - Vicki A Nejtek
- Institute for Healthy Aging , University of North Texas Health Science Center , Fort Worth , Texas 76107 , United States
| | - Michael F Salvatore
- Institute for Healthy Aging , University of North Texas Health Science Center , Fort Worth , Texas 76107 , United States
| |
Collapse
|
9
|
Salvatore MF, McInnis TR, Cantu MA, Apple DM, Pruett BS. Tyrosine Hydroxylase Inhibition in Substantia Nigra Decreases Movement Frequency. Mol Neurobiol 2018; 56:2728-2740. [PMID: 30056575 DOI: 10.1007/s12035-018-1256-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 07/17/2018] [Indexed: 10/28/2022]
Abstract
Reduced movement frequency or physical activity (bradykinesia) occurs with high prevalence in the elderly. However, loss of striatal tyrosine hydroxylase (TH) in aging humans, non-human primates, or rodents does not reach the ~ 80% loss threshold associated with bradykinesia onset in Parkinson's disease. Moderate striatal dopamine (DA) loss, either following TH inhibition or decreased TH expression, may not affect movement frequency. In contrast, moderate DA or TH loss in the substantia nigra (SN), as occurs in aging, is of similar magnitude (~ 40%) to nigral TH loss at bradykinesia onset in Parkinson's disease. In aged rats, increased TH expression and DA in SN alone increases movement frequency, suggesting aging-related TH and DA loss in the SN contributes to aging-related bradykinesia or decreased physical activity. To test this hypothesis, the SN was targeted with bilateral guide cannula in young (6 months old) rats, in a within-subjects design, to evaluate the impact of nigral TH inhibition on movement frequency and speed. The TH inhibitor, α-methyl-p-tyrosine (AMPT) reduced nigral DA (~ 40%) 45-150 min following infusion, without affecting DA in striatum, nucleus accumbens, or adjacent ventral tegmental area. Locomotor activity in the open-field was recorded up to 3 h following nigral saline or AMPT infusion in each test subject. During the period of nigra-specific DA reduction, movement frequency, but not movement speed, was significantly decreased. These results indicate that DA or TH loss in the SN, as observed in aging, contributes as a central mechanism of reduced movement frequency.
Collapse
Affiliation(s)
- Michael F Salvatore
- Institute for Healthy Aging and Center for Neuroscience Discovery, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX, 76107, USA.
| | - Tamara R McInnis
- Institute for Healthy Aging and Center for Neuroscience Discovery, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX, 76107, USA
| | - Mark A Cantu
- Institute for Healthy Aging and Center for Neuroscience Discovery, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX, 76107, USA
| | - Deana M Apple
- Department of Cell Systems and Anatomy, Barshop Institute for Aging and Longevity Studies, UT Health San Antonio, San Antonio, TX, 78229, USA
| | - Brandon S Pruett
- Department of Psychiatry and Human Behavior, Warren Alpert Medical School of Brown University, Providence, RI, 02912, USA.,Department of Pharmacology, Toxicology, & Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA, 71130, USA
| |
Collapse
|
10
|
Johnson M, Salvatore M, Maiolo S, Bobrovskaya L. Tyrosine hydroxylase as a sentinel for central and peripheral tissue responses in Parkinson’s progression: Evidence from clinical studies and neurotoxin models. Prog Neurobiol 2018; 165-167:1-25. [DOI: 10.1016/j.pneurobio.2018.01.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 12/07/2017] [Accepted: 01/10/2018] [Indexed: 12/25/2022]
|
11
|
Salvatore MF, Terrebonne J, Cantu MA, McInnis TR, Venable K, Kelley P, Kasanga EA, Latimer B, Owens CL, Pruett BS, Yu Y, Luedtke R, Forster MJ, Sumien N, Ingram DK. Dissociation of Striatal Dopamine and Tyrosine Hydroxylase Expression from Aging-Related Motor Decline: Evidence from Calorie Restriction Intervention. J Gerontol A Biol Sci Med Sci 2017. [PMID: 28637176 DOI: 10.1093/gerona/glx119] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The escalating increase in retirees living beyond their eighth decade brings increased prevalence of aging-related impairments, including locomotor impairment (Parkinsonism) that may affect ~50% of those reaching age 80, but has no confirmed neurobiological mechanism. Lifestyle strategies that attenuate motor decline, and its allied mechanisms, must be identified. Aging studies report little to moderate loss of striatal dopamine (DA) or tyrosine hydroxylase (TH) in nigrostriatal terminals, in contrast to ~70%-80% loss associated with bradykinesia onset in Parkinson's disease. These studies evaluated the effect of ~6 months 30% calorie restriction (CR) on nigrostriatal DA regulation and aging-related locomotor decline initiated at 12 months of age in Brown-Norway Fischer F1 hybrid rats. The aging-related decline in locomotor activity was prevented by CR. However, striatal DA or TH expression was decreased in the CR group, but increased in substantia nigra versus the ad libitum group or 12-month-old cohort. In a 4- to 6-month-old cohort, pharmacological TH inhibition reduced striatal DA ~30%, comparable with decreases reported in aged rats and the CR group, without affecting locomotor activity. The dissociation of moderate striatal DA reduction from locomotor activity seen in both studies suggests that aging-related decreases in striatal DA are dissociated from locomotor decline.
Collapse
Affiliation(s)
- Michael F Salvatore
- Institute for Healthy Aging and Center for Neuroscience Discovery, University of North Texas Health Science Center, Fort Worth
| | | | - Mark A Cantu
- Institute for Healthy Aging and Center for Neuroscience Discovery, University of North Texas Health Science Center, Fort Worth
| | - Tamara R McInnis
- Institute for Healthy Aging and Center for Neuroscience Discovery, University of North Texas Health Science Center, Fort Worth
| | - Katy Venable
- Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Parker Kelley
- Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Ella A Kasanga
- Institute for Healthy Aging and Center for Neuroscience Discovery, University of North Texas Health Science Center, Fort Worth
| | - Brian Latimer
- Louisiana State University Health Sciences Center-Shreveport
| | | | | | - Yongmei Yu
- Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Robert Luedtke
- Institute for Healthy Aging and Center for Neuroscience Discovery, University of North Texas Health Science Center, Fort Worth
| | - Michael J Forster
- Institute for Healthy Aging and Center for Neuroscience Discovery, University of North Texas Health Science Center, Fort Worth
| | - Nathalie Sumien
- Institute for Healthy Aging and Center for Neuroscience Discovery, University of North Texas Health Science Center, Fort Worth
| | - Donald K Ingram
- Pennington Biomedical Research Center, Baton Rouge, Louisiana
| |
Collapse
|
12
|
Maia TV, Conceição VA. The Roles of Phasic and Tonic Dopamine in Tic Learning and Expression. Biol Psychiatry 2017; 82:401-412. [PMID: 28734459 DOI: 10.1016/j.biopsych.2017.05.025] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 05/08/2017] [Accepted: 05/28/2017] [Indexed: 01/26/2023]
Abstract
Tourette syndrome (TS) prominently involves dopaminergic disturbances, but the precise nature of those disturbances has remained elusive. A substantial body of empirical work and recent computational models have characterized the specific roles of phasic and tonic dopamine (DA) in action learning and selection, respectively. Using insights from this work and models, we suggest that TS involves increases in both phasic and tonic DA, which produce increased propensities for tic learning and expression, respectively. We review the evidence from reinforcement-learning and habit-learning studies in TS, which supports the idea that TS involves increased phasic DA responses; we also review the evidence that tics engage the habit-learning circuitry. On the basis of these findings, we suggest that tics are exaggerated, maladaptive, and persistent motor habits reinforced by aberrant, increased phasic DA responses. Increased tonic DA amplifies the tendency to execute learned tics and also provides a fertile ground of motor hyperactivity for tic learning. We review evidence suggesting that antipsychotics may counter both the increased propensity for tic expression, by increasing excitability in the indirect pathway, and the increased propensity for tic learning, by shifting plasticity in the indirect pathway toward long-term potentiation (and possibly also through more complex mechanisms). Finally, we review evidence suggesting that low doses of DA agonists that effectively treat TS decrease both phasic and tonic DA, thereby also reducing the propensity for both tic learning and tic expression, respectively.
Collapse
Affiliation(s)
- Tiago V Maia
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
| | - Vasco A Conceição
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| |
Collapse
|
13
|
Cass WA, Peters LE. Reduced ability of calcitriol to promote augmented dopamine release in the lesioned striatum of aged rats. Neurochem Int 2017; 108:222-229. [PMID: 28390950 DOI: 10.1016/j.neuint.2017.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 03/13/2017] [Accepted: 04/03/2017] [Indexed: 11/18/2022]
Abstract
Parkinson's disease (PD) is a progressive and debilitating neurodegenerative disorder that affects over one million people in the United States. Previous studies, carried out in young adult rats, have shown that calcitriol, the active metabolite of vitamin D, can be neuroprotective in 6-hydroxydopamine (6-OHDA) models of PD. However, as PD usually affects older individuals, the ability of calcitriol to promote dopaminergic recovery was examined in lesioned young adult (4 month old), middle-aged (14 month old) and aged (22 month old) rats. Animals were given a single injection of 12 μg 6-OHDA into the right striatum. Four weeks later they were administered vehicle or calcitriol (1.0 μg/kg, s.c.) once a day for eight consecutive days. In vivo microdialysis experiments were carried out three weeks after the calcitriol or vehicle treatments to measure potassium and amphetamine evoked overflow of DA from both the left and right striata. In control animals treated with 6-OHDA and vehicle there were significant reductions in evoked overflow of DA on the lesioned side of the brain compared to the contralateral side. The calcitriol treatments significantly increased evoked overflow of DA from the lesioned striatum in both the young adult and middle-aged rats. However, the calcitriol treatments did not significantly augment DA overflow in the aged rats. Postmortem tissue levels of striatal DA were also increased in the young and middle-aged animals, but not in the aged animals. In the substantia nigra, the calcitriol treatments led to increased levels of DA in all three age groups. Thus, the effects of calcitriol were similar in the young adult and middle-aged animals, but in the aged animals the effects of calcitriol were diminished. These results suggest that calcitriol may help promote recovery of dopaminergic functioning in injured nigrostriatal neurons; however, the effectiveness of calcitriol may be reduced in aging.
Collapse
Affiliation(s)
- Wayne A Cass
- Department of Anatomy and Neurobiology, University of Kentucky College of Medicine, Lexington, KY, USA.
| | - Laura E Peters
- Department of Anatomy and Neurobiology, University of Kentucky College of Medicine, Lexington, KY, USA
| |
Collapse
|
14
|
Bentea E, Van Liefferinge J, Verbruggen L, Martens K, Kobayashi S, Deneyer L, Demuyser T, Albertini G, Maes K, Sato H, Smolders I, Lewerenz J, Massie A. Zonisamide attenuates lactacystin-induced parkinsonism in mice without affecting system x c<sup/>. Exp Neurol 2016; 290:15-28. [PMID: 28024798 DOI: 10.1016/j.expneurol.2016.12.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 12/15/2016] [Accepted: 12/21/2016] [Indexed: 11/29/2022]
Abstract
Zonisamide (ZNS), an anticonvulsant drug exhibiting symptomatic effects in Parkinson's disease (PD), was recently reported to exert neuroprotection in rodent models. One of the proposed neuroprotective mechanisms involves increased protein expression of xCT, the specific subunit of the cystine/glutamate antiporter system xc-, inducing glutathione (GSH) synthesis. Here, we investigated the outcome of ZNS treatment in a mouse model of PD based on intranigral proteasome inhibition, and whether the observed effects would be mediated by system xc-. The proteasome inhibitor lactacystin (LAC) was administered intranigrally to male C57BL/6J mice receiving repeated intraperitoneal injections of either ZNS 30mgkg-1 or vehicle. Drug administration was initiated three days prior to stereotaxic LAC injection and was maintained until six days post-surgery. One week after lesion, mice were behaviorally assessed and investigated in terms of nigrostriatal neurodegeneration and molecular changes at the level of the basal ganglia, including expression levels of xCT. ZNS reduced the loss of nigral dopaminergic neurons following LAC injection and the degree of sensorimotor impairment. ZNS failed, however, to modulate xCT expression in basal ganglia of lesioned mice. In a separate set of experiments, the impact of ZNS treatment on system xc- was investigated in control conditions in vivo as well as in vitro. Similarly, ZNS did not influence xCT or glutathione levels in naive male C57BL/6J mice, nor did it alter system xc- activity or glutathione content in vitro. Taken together, these results demonstrate that ZNS treatment provides neuroprotection and behavioral improvement in a PD mouse model based on proteasome inhibition via system xc- independent mechanisms.
Collapse
Affiliation(s)
- Eduard Bentea
- Department of Pharmaceutical Biotechnology and Molecular Biology, Center for Neurosciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Joeri Van Liefferinge
- Department of Pharmaceutical Chemistry and Drug Analysis, Center for Neurosciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Lise Verbruggen
- Department of Pharmaceutical Biotechnology and Molecular Biology, Center for Neurosciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Katleen Martens
- Department of Pharmaceutical Biotechnology and Molecular Biology, Center for Neurosciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Sho Kobayashi
- Department of Food and Applied Life Sciences, Yamagata University, Yamagata, Japan
| | - Lauren Deneyer
- Department of Pharmaceutical Biotechnology and Molecular Biology, Center for Neurosciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Thomas Demuyser
- Department of Pharmaceutical Chemistry and Drug Analysis, Center for Neurosciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Giulia Albertini
- Department of Pharmaceutical Chemistry and Drug Analysis, Center for Neurosciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Katrien Maes
- Department of Pharmaceutical Chemistry and Drug Analysis, Center for Neurosciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Hideyo Sato
- Laboratory of Biochemistry and Molecular Biology, Department of Medical Technology, Niigata University, Niigata, Japan
| | - Ilse Smolders
- Department of Pharmaceutical Chemistry and Drug Analysis, Center for Neurosciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Jan Lewerenz
- Department of Neurology, Ulm University, Ulm, Germany
| | - Ann Massie
- Department of Pharmaceutical Biotechnology and Molecular Biology, Center for Neurosciences, Vrije Universiteit Brussel, Brussels, Belgium.
| |
Collapse
|
15
|
Ludwig M, Apps D, Menzies J, Patel JC, Rice ME. Dendritic Release of Neurotransmitters. Compr Physiol 2016; 7:235-252. [PMID: 28135005 DOI: 10.1002/cphy.c160007] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Release of neuroactive substances by exocytosis from dendrites is surprisingly widespread and is not confined to a particular class of transmitters: it occurs in multiple brain regions, and includes a range of neuropeptides, classical neurotransmitters, and signaling molecules, such as nitric oxide, carbon monoxide, ATP, and arachidonic acid. This review is focused on hypothalamic neuroendocrine cells that release vasopressin and oxytocin and midbrain neurons that release dopamine. For these two model systems, the stimuli, mechanisms, and physiological functions of dendritic release have been explored in greater detail than is yet available for other neurons and neuroactive substances. © 2017 American Physiological Society. Compr Physiol 7:235-252, 2017.
Collapse
Affiliation(s)
- Mike Ludwig
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
| | - David Apps
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
| | - John Menzies
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Jyoti C Patel
- Department of Neurosurgery, New York University School of Medicine, New York, USA
| | - Margaret E Rice
- Department of Neurosurgery, New York University School of Medicine, New York, USA.,Department of Neuroscience and Physiology, New York University School of Medicine, New York, USA
| |
Collapse
|
16
|
Salvatore MF, Calipari ES, Jones SR. Regulation of Tyrosine Hydroxylase Expression and Phosphorylation in Dopamine Transporter-Deficient Mice. ACS Chem Neurosci 2016; 7:941-51. [PMID: 27124386 DOI: 10.1021/acschemneuro.6b00064] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Tyrosine hydroxylase (TH) and dopamine transporters (DATs) regulate dopamine (DA) neurotransmission at the biosynthesis and reuptake steps, respectively. Dysfunction or loss of these proteins occurs in impaired locomotor or addictive behavior, but little is known about the influence of DAT expression on TH function. Differences in TH phosphorylation, DA tissue content, l-DOPA biosynthesis, and DA turnover exist between the somatodendritic and terminal field compartments of nigrostriatal and mesoaccumbens pathways. We examined whether differential DAT expression affects these compartmental differences in DA regulation by comparing TH expression and phosphorylation at ser31 and ser40. In heterozygous DAT knockout (KO) (+/-) mice, DA tissue content and DA turnover were unchanged relative to wild-type mice, despite a 40% reduction in DAT protein expression. In DAT KO (-/-) mice, DA turnover increased in all DA compartments, but DA tissue content decreased (90-96%) only in terminal fields. TH protein expression and phosphorylation were differentially affected within DA pathway compartments by relative expression of DAT. TH protein decreased (∼74%), though to a significantly lesser extent than DA, in striatum and nucleus accumbens (NAc) in DAT -/- mice, with no decrease in substantia nigra or ventral tegmental area. Striatal ser31 TH phosphorylation and recovery of DA relative to TH protein expression in DAT +/- and DAT -/- mice decreased, whereas ser40 TH phosphorylation increased ∼2- to 3-fold in striatum and NAc of DAT -/- mice. These results suggest that DAT expression affects TH expression and phosphorylation largely in DA terminal field compartments, further corroborating evidence for dichotomous regulation of TH between somatodendritic and terminal field compartments of the nigrostriatal and mesoaccumbens pathways.
Collapse
Affiliation(s)
- Michael F. Salvatore
- Department
of Pharmacology, Toxicology and Neuroscience, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130, United States
| | - Erin S. Calipari
- Department
of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, United States
| | - Sara R. Jones
- Department
of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, United States
| |
Collapse
|
17
|
Activation of D1/5 Dopamine Receptors: A Common Mechanism for Enhancing Extinction of Fear and Reward-Seeking Behaviors. Neuropsychopharmacology 2016; 41:2072-81. [PMID: 26763483 PMCID: PMC4908654 DOI: 10.1038/npp.2016.5] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 12/21/2015] [Accepted: 01/07/2016] [Indexed: 01/05/2023]
Abstract
Dopamine is critical for many processes that drive learning and memory, including motivation, prediction error, incentive salience, memory consolidation, and response output. Theories of dopamine's function in these processes have, for the most part, been developed from behavioral approaches that examine learning mechanisms in appetitive tasks. A parallel and growing literature indicates that dopamine signaling is involved in consolidation of memories into stable representations in aversive tasks such as fear conditioning. Relatively little is known about how dopamine may modulate memories that form during extinction, when organisms learn that the relation between previously associated events is severed. We investigated whether fear and reward extinction share common mechanisms that could be enhanced with dopamine D1/5 receptor activation. Pharmacological activation of dopamine D1/5 receptors (with SKF 81297) enhanced extinction of both cued and contextual fear. These effects also occurred in the extinction of cocaine-induced conditioned place preference, suggesting that the observed effects on extinction were not specific to a particular type of procedure (aversive or appetitive). A cAMP/PKA biased D1 agonist (SKF 83959) did not affect fear extinction, whereas a broadly efficacious D1 agonist (SKF 83822) promoted fear extinction. Together, these findings show that dopamine D1/5 receptor activation is a target for the enhancement of fear or reward extinction.
Collapse
|
18
|
Rice ME, Patel JC. Somatodendritic dopamine release: recent mechanistic insights. Philos Trans R Soc Lond B Biol Sci 2016; 370:rstb.2014.0185. [PMID: 26009764 DOI: 10.1098/rstb.2014.0185] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Dopamine (DA) is a key transmitter in motor, reward and cogitative pathways, with DA dysfunction implicated in disorders including Parkinson's disease and addiction. Located in midbrain, DA neurons of the substantia nigra pars compacta project via the medial forebrain bundle to the dorsal striatum (caudate putamen), and DA neurons in the adjacent ventral tegmental area project to the ventral striatum (nucleus accumbens) and prefrontal cortex. In addition to classical vesicular release from axons, midbrain DA neurons exhibit DA release from their cell bodies and dendrites. Somatodendritic DA release leads to activation of D2 DA autoreceptors on DA neurons that inhibit their firing via G-protein-coupled inwardly rectifying K(+) channels. This helps determine patterns of DA signalling at distant axonal release sites. Somatodendritically released DA also acts via volume transmission to extrasynaptic receptors that modulate local transmitter release and neuronal activity in the midbrain. Thus, somatodendritic release is a pivotal intrinsic feature of DA neurons that must be well defined in order to fully understand the physiology and pathophysiology of DA pathways. Here, we review recent mechanistic aspects of somatodendritic DA release, with particular emphasis on the Ca(2+) dependence of release and the potential role of exocytotic proteins.
Collapse
Affiliation(s)
- Margaret E Rice
- Department of Neurosurgery, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA Department of Neuroscience and Physiology, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA
| | - Jyoti C Patel
- Department of Neurosurgery, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA
| |
Collapse
|
19
|
Salvatore MF, Terrebonne J, Fields V, Nodurft D, Runfalo C, Latimer B, Ingram DK. Initiation of calorie restriction in middle-aged male rats attenuates aging-related motoric decline and bradykinesia without increased striatal dopamine. Neurobiol Aging 2016; 37:192-207. [PMID: 26610387 PMCID: PMC4688216 DOI: 10.1016/j.neurobiolaging.2015.10.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 10/07/2015] [Accepted: 10/08/2015] [Indexed: 01/07/2023]
Abstract
Aging-related bradykinesia affects ∼ 15% of those reaching age 65 and 50% of those reaching their 80s. Given this high risk and lack of pharmacologic therapeutics, noninvasive lifestyle strategies should be identified to diminish its risk and identify the neurobiological targets to reduce aging-related bradykinesia. Early-life, long-term calorie restriction (CR) attenuates aging-related bradykinesia in rodents. Here, we addressed whether CR initiation at middle age could attenuate aging-related bradykinesia and motoric decline measured as rotarod performance. A 30% CR regimen was implemented for 6 months duration in 12-month-old male Brown-Norway Fischer 344 F1 hybrid rats after establishing individual baseline locomotor activities. Locomotor capacity was assessed every 6 weeks thereafter. The ad libitum group exhibited predictably decreased locomotor activity, except movement speed, out to 18 months of age. In contrast, in the CR group, movement number and horizontal activity did not decrease during the 6-month trial, and aging-related decline in rotarod performance was attenuated. The response to CR was influenced by baseline locomotor activity. The lower the locomotor activity level at baseline, the greater the response to CR. Rats in the lower 50th percentile surpassed their baseline level of activity, whereas rats in the top 50th percentile decreased at 6 weeks and then returned to baseline by 12 weeks of CR. We hypothesized that nigrostriatal dopamine tissue content would be greater in the CR group and observed a modest increase only in substantia nigra with no group differences in striatum, nucleus accumbens, or ventral tegmental area. These results indicate that initiation of CR at middle age may reduce aging-related bradykinesia, and, furthermore, subjects with below average locomotor activity may increase baseline activity. Sustaining nigral dopamine neurotransmission may be one component of preserving locomotor capabilities during aging.
Collapse
Affiliation(s)
- Michael F Salvatore
- Department of Pharmacology, Toxicology, & Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA, USA; Department of Pharmacology & Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, USA.
| | - Jennifer Terrebonne
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Victoria Fields
- Department of Pharmacology, Toxicology, & Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Danielle Nodurft
- Department of Pharmacology, Toxicology, & Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Cori Runfalo
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Brian Latimer
- Department of Pharmacology, Toxicology, & Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Donald K Ingram
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| |
Collapse
|
20
|
The MAO-B inhibitor deprenyl reduces the oral tremor and the dopamine depletion induced by the VMAT-2 inhibitor tetrabenazine. Behav Brain Res 2015; 298:188-91. [PMID: 26590367 DOI: 10.1016/j.bbr.2015.11.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 11/06/2015] [Accepted: 11/07/2015] [Indexed: 11/22/2022]
Abstract
Tetrabenazine (TBZ) is prescribed for the treatment of chorea associated with Huntington's disease. Via inhibition of the vesicular monoamine transporter (VMAT-2), TBZ blocks dopamine (DA) storage and depletes striatal DA; this drug also has been shown to induce Parkinsonian motor side effects in patients. Recently, TBZ was shown to induce tremulous jaw movements (TJMs) in rats and mice. TJMs are an oral tremor that has many of the characteristics of Parkinsonian tremor in humans. The present study focused upon the ability of the well-established antiparkinsonian agent deprenyl to attenuate the behavioral and neurochemical effects of 2.0mg/kg TBZ. Deprenyl is a selective and irreversible inhibitor of monoamine oxidase-B, and administration of deprenyl produced a dose-related suppression of TBZ-induced TJMs. A second experiment employed in vivo microdialysis to examine extracellular DA levels in the ventrolateral striatum, the neostriatal region most closely associated with the production of TJMs, after administration of TBZ and deprenyl. Consistent with the behavioral data, TBZ alone produced a biphasic effect on extracellular DA, with an initial increases followed by a prolonged decrease during the period in which TJMs are displayed. Co-administration of deprenyl with TBZ increased DA levels compared to rats treated with TBZ alone. These results provide support for use of TBZ as a rodent model of Parkinsonism, and future studies should utilize this model to evaluate putative anti-Parkinsonian agents.
Collapse
|
21
|
Prescott IA, Liu LD, Dostrovsky JO, Hodaie M, Lozano AM, Hutchison WD. Lack of depotentiation at basal ganglia output neurons in PD patients with levodopa-induced dyskinesia. Neurobiol Dis 2014; 71:24-33. [PMID: 25116960 DOI: 10.1016/j.nbd.2014.08.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 07/29/2014] [Accepted: 08/01/2014] [Indexed: 11/26/2022] Open
Abstract
Parkinson's disease (PD), characterized by the loss of dopaminergic nigrostriatal projections, is a debilitating neurodegenerative disease which produces bradykinesia, rigidity, tremor and postural instability. The dopamine precursor levodopa (L-Dopa) is the most effective treatment for the amelioration of PD signs and symptoms, but long-term administration can lead to disabling motor fluctuations and L-Dopa-induced dyskinesias. In animal models of PD, a form of plasticity called depotentiation, or the reversal of previous potentiation, is selectively lost after the development of dyskinetic movements following L-Dopa treatment. We investigated whether low frequency stimulation (LFS) in the globus pallidus internus (GPi) and substantia nigra pars reticulata (SNr) could induce depotentiation at synapses that had already undergone high frequency stimulation (HFS)-induced potentiation. To do so, we measured the field potentials (fEPs) evoked by stimulation from a nearby microelectrode in 28 patients undergoing implantation of deep brain stimulating (DBS) electrodes in the subthalamic nucleus (STN) or GPi. We found that GPi and SNr synapses in patients with less severe dyskinesia underwent greater depotentiation following LFS than in patients with more severe dyskinesia. This demonstration of impaired depotentiation in basal ganglia output nuclei in PD patients with dyskinesia is an important validation of animal models of levodopa-induced dyskinesia. The ability of a synapse to reverse previous potentiation may be crucial to the normal function of the BG, perhaps by preventing saturation of the storage capacity required in motor learning and optimal motor function. Loss of this ability at the output nuclei may underlie, or contribute to the cellular basis of dyskinetic movements.
Collapse
Affiliation(s)
- I A Prescott
- Department of Physiology, University of Toronto, Canada.
| | - L D Liu
- Department of Physiology, University of Toronto, Canada
| | | | - M Hodaie
- Dept. of Surgery, Division of Neurosurgery, Toronto Western Research Institute, Canada; Krembil Neuroscience Centre, Canada
| | - A M Lozano
- Dept. of Surgery, Division of Neurosurgery, Toronto Western Research Institute, Canada; Krembil Neuroscience Centre, Canada
| | - W D Hutchison
- Department of Physiology, University of Toronto, Canada; Dept. of Surgery, Division of Neurosurgery, Toronto Western Research Institute, Canada; Krembil Neuroscience Centre, Canada
| |
Collapse
|
22
|
Gupta S, Sharma B. Pharmacological benefits of agomelatine and vanillin in experimental model of Huntington's disease. Pharmacol Biochem Behav 2014; 122:122-35. [DOI: 10.1016/j.pbb.2014.03.022] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 03/01/2014] [Accepted: 03/23/2014] [Indexed: 12/20/2022]
|
23
|
Gupta S, Sharma B. Protective effects of phosphodiesterase-1 (PDE1) and ATP sensitive potassium (KATP) channel modulators against 3-nitropropionic acid induced behavioral and biochemical toxicities in experimental Huntington׳s disease. Eur J Pharmacol 2014; 732:111-22. [DOI: 10.1016/j.ejphar.2014.03.032] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 03/15/2014] [Accepted: 03/24/2014] [Indexed: 12/16/2022]
|
24
|
Cass WA, Peters LE, Fletcher AM, Yurek DM. Calcitriol promotes augmented dopamine release in the lesioned striatum of 6-hydroxydopamine treated rats. Neurochem Res 2014; 39:1467-76. [PMID: 24858239 DOI: 10.1007/s11064-014-1331-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 05/06/2014] [Accepted: 05/09/2014] [Indexed: 10/25/2022]
Abstract
Current therapies for Parkinson's disease (PD) offer symptomatic relief but do not provide a cure or slow the disease process. Treatments that could halt progression of the disease or help restore function to damaged neurons would be of substantial benefit. Calcitriol, the active metabolite of vitamin D, has been shown to have significant effects on the brain. These effects include upregulating trophic factor levels, and reducing the severity of some central nervous system lesions. While previous studies have shown that calcitriol can be neuroprotective in 6-hydroxydopamine (6-OHDA) rodent models of PD, the present experiments were designed to examine the ability of calcitriol to promote restoration of extracellular dopamine (DA) levels and tissue content of DA in animals previously lesioned with 6-OHDA. Male Fischer-344 rats were given a single injection of 12 µg 6-OHDA into the right striatum. Four weeks later the animals were administered vehicle or calcitriol (0.3 or 1.0 µg/kg, s.c.) once a day for eight consecutive days. Three weeks after the calcitriol treatments in vivo microdialysis experiments were conducted to measure potassium and amphetamine evoked overflow of DA from both the left and right striata. In control animals treated with 6-OHDA and vehicle there were significant reductions in both potassium and amphetamine evoked overflow of DA on the lesioned side of the brain compared to the contralateral side. In animals treated with 6-OHDA followed by calcitriol there was significantly greater potassium and amphetamine evoked overflow of DA from the lesioned striatum compared to that from the control animals. The calcitriol treatments also led to increases in postmortem tissue levels of DA in the striatum and substantia nigra. These results suggest that calcitriol may help promote recovery of dopaminergic functioning in injured nigrostriatal neurons.
Collapse
Affiliation(s)
- Wayne A Cass
- Department of Anatomy and Neurobiology, MN-225 Chandler Medical Center, University of Kentucky College of Medicine, Lexington, KY, 40536-0298, USA,
| | | | | | | |
Collapse
|
25
|
Shimokawa N, Yousefi B, Morioka S, Yamaguchi S, Ohsawa A, Hayashi H, Azuma A, Mizuno H, Kasagi M, Masuda H, Jingu H, Furudate SI, Haijima A, Takatsuru Y, Iwasaki T, Umezu M, Koibuchi N. Altered cerebellum development and dopamine distribution in a rat genetic model with congenital hypothyroidism. J Neuroendocrinol 2014; 26:164-75. [PMID: 24460919 DOI: 10.1111/jne.12135] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 12/30/2013] [Accepted: 01/20/2014] [Indexed: 12/14/2022]
Abstract
Thyroid hormones play crucial roles in the development and functional maintenance of the central nervous system. Despite extensive studies of the neural function of thyroid hormones, little is known about the effects of hypothyroidism on behavioural traits and the mechanisms underlying such effects. In the present study, we report an investigation of congenitally hypothyroid mutant rdw rats, revealing a novel function of thyroid hormones in the central nervous system. The rdw rats were subjected to behavioural analyses such as the rotarod test, open field test and circadian activity measurement. To determine the cause of behavioural disorders, cerebellar morphogenesis was examined by immunohistochemical analysis, and the axonal transport of dopamine in the nigrostriatal pathway was analysed by high-performance liquid chromatography and western blotting. The effects of thyroxine administration to the rdw rats were examined by behavioural analysis. The rdw rats showed severe impairment of motor coordination and balance. This could be explained by the fact that the rats showed severe retardation of cerebellar morphogenesis, which correlates with the small somata and poor dendritic arborisation of Purkinje cells and retarded migration of granule cells particularly during the first two postnatal weeks. Moreover, the rdw rats showed hypoactivity, characterised by decreased circadian locomotor activity. After weaning, thyroxine administration improved the dwarfism in rdw rats but had no effect on cerebellar function. In addition, the rdw rats showed anxiety and depression intrinsically to novel surroundings. Interestingly, the rdw rats showed high levels of dopamine in the substantia nigra and low levels in the striatum, an important centre for the coordination of behaviour. Furthermore, low levels of tubulin in the striatum were detected, indicating the aberrant axonal transport of dopamine in the nigrostriatal pathway as a result of the reduced delivery of microtubules. These findings indicate an important function of thyroid hormones in cerebellar formation and in the regulation of axonal transport of dopamine. Moreover, rdw rats will be useful for studies of brain function and behavioural disorders in congenital hypothyroidism.
Collapse
Affiliation(s)
- N Shimokawa
- Department of Integrative Physiology, Gunma University Graduate School of Medicine, Gunma, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Gupta S, Sharma B. Pharmacological benefit of I(1)-imidazoline receptors activation and nuclear factor kappa-B (NF-κB) modulation in experimental Huntington's disease. Brain Res Bull 2014; 102:57-68. [PMID: 24582883 DOI: 10.1016/j.brainresbull.2014.02.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 02/08/2014] [Accepted: 02/12/2014] [Indexed: 01/14/2023]
Abstract
Huntington's disease (HD), a neurodegenerative disorder, is characterized by progressive motor dysfunction, emotional disturbances, dementia, weight loss and anxiety. The tremendous amount of research work is required to identify new pharmacological agents of therapeutic utility to combat this condition. This study investigates the effect of selective modulator of I1-imidazoline receptor (moxonidine) as well as nuclear factor kappa-B (NF-κB) (natrium diethyl dithio carbamate trihydrate-NDDCT) on 3-nitropropionic acid (3-NPA) induced experimental HD condition. 3-NPA was used to induce mitochondrial damage and associated HD symptoms in rats. Anxiety was assessed using Elevated plus maze-EPM and learning-memory was assessed using EPM and Morris water maze-MWM. Different biochemical estimations were used to assess brain striatum oxidative stress (lipid peroxide, superoxide dismutase and catalase), nitric oxide levels (nitrite/nitrate), cholinergic activity (brain striatum acetyl cholinesterase activity), and mitochondrial enzyme complex (I, II and IV) activities. 3-NPA has induced anxiety, impaired learning-memory with a reduction in body weight, locomotor activity, grip strength. It has increased brain striatum acetylcholinesterase-AChE activity, oxidative stress (lipid peroxide, nitrite/nitrate, superoxide dismutase and catalase) and impaired mitochondrial complex enzyme (I, II and IV) activities. Tetrabenazine-TBZ (monoamine storage inhibitor) was used as positive control. Treatment with moxonidine, NDDCT and TBZ significantly attenuated 3-NPA induced reduction in body weight, locomotor activity, grip strength, anxiety as well as impaired learning and memory. Administration of these agents attenuated 3-NPA induced various biochemical impairments. Therefore, modulation of I1-imidazoline receptor as well as NF-κB may be considered as potential pharmacological agents for the management of 3-NPA induced HD.
Collapse
Affiliation(s)
- Surbhi Gupta
- Neuropharmacology Lab., Department of Pharmacology, School of Pharmacy, Bharat Institute of Technology, Partapur Bypass, Meerut, Uttar Pradesh, India.
| | - Bhupesh Sharma
- Department of Pharmacology, School of Pharmacy, Bharat Institute of Technology, Partapur Bypass, Meerut, Uttar Pradesh, India; CNS Pharmacology, Conscience Research, Pocket F-233, B, Dilshad Garden, Delhi 110095, India.
| |
Collapse
|
27
|
Salvatore MF. ser31 Tyrosine hydroxylase phosphorylation parallels differences in dopamine recovery in nigrostriatal pathway following 6-OHDA lesion. J Neurochem 2014; 129:548-58. [PMID: 24410633 DOI: 10.1111/jnc.12652] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 12/13/2013] [Accepted: 01/02/2014] [Indexed: 12/19/2022]
Abstract
Compensatory mechanisms in dopamine (DA) signaling have long been proposed to delay onset of locomotor symptoms during Parkinson's disease progression until ~ 80% loss of striatal DA occurs. Increased striatal dopamine turnover has been proposed to be a part of this compensatory response, but may occur after locomotor symptoms. Increased tyrosine hydroxylase (TH) activity has also been proposed as a mechanism, but the impact of TH protein loss upon site-specific TH phosphorylation in conjunction with the impact on DA tissue content is not known. The tissue content of DA was determined against TH protein loss in the striatum and substantia nigra (SN) following 6-hydroxydopamine lesion in the medial forebrain bundle in young Sprague-Dawley male rats. Although DA predictably decreased in both regions following 6-hydroxydopamine, there was a significant difference in DA loss between the striatum (75%) and SN (40%), despite similar TH protein loss. Paradoxically, there was a significant decrease in DA against remaining TH protein in striatum, but a significant increase in DA against remaining TH in SN. In the SN, increased DA per remaining TH protein was matched by increased ser31, but not ser40, TH phosphorylation. In striatum, both ser31 and ser40 phosphorylation decreased, reflecting decreased DA per TH. However, in control nigral and striatal tissue, only ser31 phosphorylation correlated with DA per TH protein. Combined, these results suggest that the phosphorylation of ser31 in the SN may be a mechanism to increase DA biosynthesis against TH protein loss in an in vivo model of Parkinson's disease. Properties of dopamine biosynthesis were evaluated in the 6-OHDA model of Parkinson's disease by studying the impact of tyrosine hydroxylase (TH) protein loss on its own phosphorylation and dopamine (DA) tissue content in rat nigrostriatal pathway. A dichotomous response was observed between striatum and substantia nigra in that dopamine per remaining TH decreased in striatum, but increased in substantia nigra. Phosphorylation at ser31 reflected these differences, indicating that ser31 phosphorylation may be critical to maintain dopamine with progressive TH protein loss. Drawings are from slides purchased from Motifolio (http://motifolio.com/).
Collapse
Affiliation(s)
- Michael F Salvatore
- Department of Pharmacology, Toxicology& Neuroscience, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA
| |
Collapse
|
28
|
Pruett BS, Salvatore MF. Nigral GFRα1 infusion in aged rats increases locomotor activity, nigral tyrosine hydroxylase, and dopamine content in synchronicity. Mol Neurobiol 2013; 47:988-99. [PMID: 23321789 DOI: 10.1007/s12035-013-8397-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 01/03/2013] [Indexed: 02/05/2023]
Abstract
Delivery of exogenous glial cell line-derived neurotrophic factor (GDNF) increases locomotor activity in rodent models of aging and Parkinson's disease in conjunction with increased dopamine (DA) tissue content in substantia nigra (SN). Striatal GDNF infusion also increases expression of GDNF's cognate receptor, GFRα1, and tyrosine hydroxylase (TH) ser31 phosphorylation in the SN of aged rats long after elevated GDNF is no longer detectable. In aging, expression of soluble GFRα1 in the SN decreases in association with decreased TH expression, TH ser31 phosphorylation, DA tissue content, and locomotor activity. Thus, we hypothesized that, in aged rats, replenishing soluble GFRα1 in SN could reverse these deficits and increase locomotor activity. We determined that the quantity of soluble GFRα1 in young adult rat SN is ~3.6 ng. To replenish age-related loss, which is ~30 %, we infused 1 ng soluble GFRα1 bilaterally into SN of aged male rats and observed increased locomotor activity compared to vehicle-infused rats up to 4 days following infusion, with maximal effects on day 3. Five days after infusion, however, neither locomotor activity nor nigrostriatal neurochemical measures were significantly different between groups. In a separate cohort of male rats, nigral, but not striatal, DA, TH, and TH ser31 phosphorylation were increased 3 days following unilateral infusion of 1 ng soluble GFRα1into SN. Therefore, in aged male rats, the transient increase in locomotor activity induced by replenishing age-related loss of soluble GFRα1is temporally matched with increased nigral dopaminergic function. Thus, expression of soluble GFRα1 in SN may be a key component in locomotor activity regulation through its influence over TH regulation and DA biosynthesis.
Collapse
Affiliation(s)
- Brandon S Pruett
- Department of Pharmacology, Louisiana State University Health Sciences Center, School of Medicine, 1501 Kings Highway, P.O. Box 33932, Shreveport, LA 71130, USA
| | | |
Collapse
|
29
|
Osório ACP, da Cunha ALMC, Khan S, Ponciano CR, Aucélio RQ. Spectrofluorimetric determination of tetrabenazine after photochemical derivatization in basic medium. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013; 100:166-170. [PMID: 22591799 DOI: 10.1016/j.saa.2012.04.060] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 04/07/2012] [Accepted: 04/13/2012] [Indexed: 05/31/2023]
Abstract
Photochemical derivatization is proposed for the spectrofluorimetric determination of tetrabenazine (TBZ). A central composite design was used to adjust experimental conditions (60 min of UV in a 0.45 mol L(-1) NaOH solution) enabling the improvement of the analyte signal-to-blank ratio of one order of magnitude, when compared to the TBZ original fluorescence. Limit of quantification was 4.7×10(-8) mol L(-1) but the detection power can be improved at least 10 times using solid phase extraction that also allows the separation of the analyte from matrix components, enabling the analysis of biologic fluids. Linear range covered at least three orders of magnitude. The combined uncertainty of the determination (at a 5×10(-6) mol L(-1)) was 16%. Recoveries of TBZ in the analyses of a pharmaceutical formulation were in agreement with the ones obtained using a HPLC method. Recovery in saliva (5×10(-7) mol L(-1) of TBZ) was 90±3% (n=3). The procedure minimizes the use of toxic chemical derivatization reagents and the generation of hazardous waste.
Collapse
Affiliation(s)
- Ana C P Osório
- Chemistry Department, Pontifícia Universidade Católica do Rio de Janeiro, 22451-900 Rio de Janeiro, Brazil
| | | | | | | | | |
Collapse
|
30
|
Fortin GM, Bourque MJ, Mendez JA, Leo D, Nordenankar K, Birgner C, Arvidsson E, Rymar VV, Bérubé-Carrière N, Claveau AM, Descarries L, Sadikot AF, Wallén-Mackenzie Å, Trudeau LÉ. Glutamate corelease promotes growth and survival of midbrain dopamine neurons. J Neurosci 2012; 32:17477-91. [PMID: 23197738 PMCID: PMC6621856 DOI: 10.1523/jneurosci.1939-12.2012] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 10/10/2012] [Accepted: 10/16/2012] [Indexed: 01/09/2023] Open
Abstract
Recent studies have proposed that glutamate corelease by mesostriatal dopamine (DA) neurons regulates behavioral activation by psychostimulants. How and when glutamate release by DA neurons might play this role remains unclear. Considering evidence for early expression of the type 2 vesicular glutamate transporter in mesencephalic DA neurons, we hypothesized that this cophenotype is particularly important during development. Using a conditional gene knock-out approach to selectively disrupt the Vglut2 gene in mouse DA neurons, we obtained in vitro and in vivo evidence for reduced growth and survival of mesencephalic DA neurons, associated with a decrease in the density of DA innervation in the nucleus accumbens, reduced activity-dependent DA release, and impaired motor behavior. These findings provide strong evidence for a functional role of the glutamatergic cophenotype in the development of mesencephalic DA neurons, opening new perspectives into the pathophysiology of neurodegenerative disorders involving the mesostriatal DA system.
Collapse
Affiliation(s)
- Guillaume M Fortin
- Department of Pharmacology, and Groupe de Recherche sur le Système Nerveux Central, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada H3C 3J7
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Samoudi G, Nissbrandt H, Dutia MB, Bergquist F. Noisy galvanic vestibular stimulation promotes GABA release in the substantia nigra and improves locomotion in hemiparkinsonian rats. PLoS One 2012; 7:e29308. [PMID: 22238601 PMCID: PMC3253081 DOI: 10.1371/journal.pone.0029308] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Accepted: 11/24/2011] [Indexed: 11/30/2022] Open
Abstract
Background The vestibular system is connected to spinal, cerebellar and cerebral motor control structures and can be selectively activated with external electrodes. The resulting sensation of disturbed balance can be avoided by using stochastic stimulation patterns. Adding noise to the nervous system sometimes improves function. Small clinical trials suggest that stochastic vestibular stimulation (SVS) may improve symptoms in Parkinson's disease. We have investigated this claim and possible mechanisms using the 6-hydroxydopamine (6-OHDA) hemilesion model of Parkinson's disease. Methodology/Principal Findings Animals were tested in the accelerating rod test and the Montoya staircase test of skilled forelimb use. In 6-OHDA hemilesioned animals, SVS improved rod performance by 56±11 s. At group level L-DOPA treatment had no effect, but positive responders improved time on rod by 60±19 s. Skilled forelimb use was not altered by SVS. To investigate how SVS may influence basal ganglia network activity, intracerebral microdialysis was employed in four regions of interest during and after SVS. In presence of the γ-amino buturic acid (GABA) transporter inhibitor NNC 711, SVS induced an increase in GABA to 150±15% of baseline in the substantia nigra (SN) of unlesioned animals, but had no effect in the pedunculopontine nucleus (PPN), the striatum or the ventromedial thalamus (VM). Dopamine release remained stable in all areas, as did GABA and amine concentrations in the SN of unstimulated controls. Following SVS, a sustained increase in GABA concentrations was observed in the ipsilesional, but not in the contralesional SN of 6-OHDA hemilesioned rats. In contrast, L-DOPA treatment produced a similar increase of GABA in the ipsi- and contra-lesional SN. Conclusions/Significance SVS improves rod performance in a rat model of Parkinson's disease, possibly by increasing nigral GABA release in a dopamine independent way. We propose that SVS could be useful for treating symptoms of Parkinson's disease.
Collapse
Affiliation(s)
- Ghazaleh Samoudi
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| | - Hans Nissbrandt
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| | - Mayank B. Dutia
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Filip Bergquist
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
- Department of Neurology, Sahlgrenska University Hospital, Göteborg, Sweden
- * E-mail:
| |
Collapse
|
32
|
Salvatore MF, Pruett BS. Dichotomy of tyrosine hydroxylase and dopamine regulation between somatodendritic and terminal field areas of nigrostriatal and mesoaccumbens pathways. PLoS One 2012; 7:e29867. [PMID: 22242182 PMCID: PMC3252325 DOI: 10.1371/journal.pone.0029867] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Accepted: 12/06/2011] [Indexed: 01/25/2023] Open
Abstract
Measures of dopamine-regulating proteins in somatodendritic regions are often used only as static indicators of neuron viability, overlooking the possible impact of somatodendritic dopamine (DA) signaling on behavior and the potential autonomy of DA regulation between somatodendritic and terminal field compartments. DA reuptake capacity is less in somatodendritic regions, possibly placing a greater burden on de novo DA biosynthesis within this compartment to maintain DA signaling. Therefore, regulation of tyrosine hydroxylase (TH) activity may be particularly critical for somatodendritic DA signaling. Phosphorylation of TH at ser31 or ser40 can increase activity, but their impact on L-DOPA biosynthesis in vivo is unknown. Thus, determining their relationship with L-DOPA tissue content could reveal a mechanism by which DA signaling is normally maintained. In Brown-Norway Fischer 344 F1 hybrid rats, we quantified TH phosphorylation versus L-DOPA accumulation. After inhibition of aromatic acid decarboxylase, L-DOPA tissue content per recovered TH protein was greatest in NAc, matched by differences in ser31, but not ser40, phosphorylation. The L-DOPA per catecholamine and DA turnover ratios were significantly greater in SN and VTA, suggesting greater reliance on de novo DA biosynthesis therein. These compartmental differences reflected an overall autonomy of DA regulation, as seen by decreased DA content in SN and VTA, but not in striatum or NAc, following short-term DA biosynthesis inhibition from local infusion of the TH inhibitor α-methyl-p-tyrosine, as well as in the long-term process of aging. Such data suggest ser31 phosphorylation plays a significant role in regulating TH activity in vivo, particularly in somatodendritic regions, which may have a greater reliance on de novo DA biosynthesis. Thus, to the extent that somatodendritic DA release affects behavior, TH regulation in the midbrain may be critical for DA bioavailability to influence behavior.
Collapse
Affiliation(s)
- Michael F Salvatore
- Department of Pharmacology, Toxicology and Neuroscience, Louisiana State University Health Sciences Center, Shreveport, Louisiana, United States of America.
| | | |
Collapse
|
33
|
Metabotropic Glutamate Receptor–Dopamine Interactions in the Basal Ganglia Motor Circuit. ACTA ACUST UNITED AC 2011. [DOI: 10.1201/b11284-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
34
|
Nguyen MAT, Joya JE, Kee AJ, Domazetovska A, Yang N, Hook JW, Lemckert FA, Kettle E, Valova VA, Robinson PJ, North KN, Gunning PW, Mitchell CA, Hardeman EC. Hypertrophy and dietary tyrosine ameliorate the phenotypes of a mouse model of severe nemaline myopathy. ACTA ACUST UNITED AC 2011; 134:3516-29. [PMID: 22067542 DOI: 10.1093/brain/awr274] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Nemaline myopathy, the most common congenital myopathy, is caused by mutations in genes encoding thin filament and thin filament-associated proteins in skeletal muscles. Severely affected patients fail to survive beyond the first year of life due to severe muscle weakness. There are no specific therapies to combat this muscle weakness. We have generated the first knock-in mouse model for severe nemaline myopathy by replacing a normal allele of the α-skeletal actin gene with a mutated form (H40Y), which causes severe nemaline myopathy in humans. The Acta1(H40Y) mouse has severe muscle weakness manifested as shortened lifespan, significant forearm and isolated muscle weakness and decreased mobility. Muscle pathologies present in the human patients (e.g. nemaline rods, fibre atrophy and increase in slow fibres) were detected in the Acta1(H40Y) mouse, indicating that it is an excellent model for severe nemaline myopathy. Mating of the Acta1(H40Y) mouse with hypertrophic four and a half LIM domains protein 1 and insulin-like growth factor-1 transgenic mice models increased forearm strength and mobility, and decreased nemaline pathologies. Dietary L-tyrosine supplements also alleviated the mobility deficit and decreased the chronic repair and nemaline rod pathologies. These results suggest that L-tyrosine may be an effective treatment for muscle weakness and immobility in nemaline myopathy.
Collapse
Affiliation(s)
- Mai-Anh T Nguyen
- Neuromuscular and Regenerative Medicine Unit, School of Medical Sciences, University of New South Wales, Kensington, NSW 2052, Australia
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Mendez JA, Bourque MJ, Fasano C, Kortleven C, Trudeau LE. Somatodendritic dopamine release requires synaptotagmin 4 and 7 and the participation of voltage-gated calcium channels. J Biol Chem 2011; 286:23928-37. [PMID: 21576241 PMCID: PMC3129174 DOI: 10.1074/jbc.m111.218032] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2011] [Revised: 05/09/2011] [Indexed: 11/06/2022] Open
Abstract
Somatodendritic (STD) dopamine (DA) release is a key mechanism for the autoregulatory control of DA release in the brain. However, its molecular mechanism remains undetermined. We tested the hypothesis that differential expression of synaptotagmin (Syt) isoforms explains some of the differential properties of terminal and STD DA release. Down-regulation of the dendritically expressed Syt4 and Syt7 severely reduced STD DA release, whereas terminal release required Syt1. Moreover, we found that although mobilization of intracellular Ca(2+) stores is inefficient, Ca(2+) influx through N- and P/Q-type voltage-gated channels is critical to trigger STD DA release. Our findings provide an explanation for the differential Ca(2+) requirement of terminal and STD DA release. In addition, we propose that not all sources of intracellular Ca(2+) are equally efficient to trigger this release mechanism. Our findings have implications for a better understanding of a fundamental cell biological process mediating transcellular signaling in a system critical for diseases such as Parkinson disease.
Collapse
Affiliation(s)
- Jose Alfredo Mendez
- From the Department of Pharmacology, Groupe de Recherche sur le Système Nerveux Central, Faculty of Medicine, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Marie-Josée Bourque
- From the Department of Pharmacology, Groupe de Recherche sur le Système Nerveux Central, Faculty of Medicine, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Caroline Fasano
- From the Department of Pharmacology, Groupe de Recherche sur le Système Nerveux Central, Faculty of Medicine, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Christian Kortleven
- From the Department of Pharmacology, Groupe de Recherche sur le Système Nerveux Central, Faculty of Medicine, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Louis-Eric Trudeau
- From the Department of Pharmacology, Groupe de Recherche sur le Système Nerveux Central, Faculty of Medicine, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| |
Collapse
|
36
|
Rommelfanger KS, Wichmann T. Extrastriatal dopaminergic circuits of the Basal Ganglia. Front Neuroanat 2010; 4:139. [PMID: 21103009 PMCID: PMC2987554 DOI: 10.3389/fnana.2010.00139] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Accepted: 09/23/2010] [Indexed: 11/20/2022] Open
Abstract
The basal ganglia are comprised of the striatum, the external and internal segment of the globus pallidus (GPe and GPi, respectively), the subthalamic nucleus (STN), and the substantia nigra pars compacta and reticulata (SNc and SNr, respectively). Dopamine has long been identified as an important modulator of basal ganglia function in the striatum, and disturbances of striatal dopaminergic transmission have been implicated in diseases such as Parkinson's disease (PD), addiction and attention deficit hyperactivity disorder. However, recent evidence suggests that dopamine may also modulate basal ganglia function at sites outside of the striatum, and that changes in dopaminergic transmission at these sites may contribute to the symptoms of PD and other neuropsychiatric disorders. This review summarizes the current knowledge of the anatomy, functional effects and behavioral consequences of the dopaminergic innervation to the GPe, GPi, STN, and SNr. Further insights into the dopaminergic modulation of basal ganglia function at extrastriatal sites may provide us with opportunities to develop new and more specific strategies for treating disorders of basal ganglia dysfunction.
Collapse
|
37
|
Pruett BS, Salvatore MF. GFR α-1 receptor expression in the aging nigrostriatal and mesoaccumbens pathways. J Neurochem 2010; 115:707-15. [DOI: 10.1111/j.1471-4159.2010.06963.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
38
|
Kliem MA, Pare JF, Khan ZU, Wichmann T, Smith Y. Ultrastructural localization and function of dopamine D1-like receptors in the substantia nigra pars reticulata and the internal segment of the globus pallidus of parkinsonian monkeys. Eur J Neurosci 2010; 31:836-51. [PMID: 20374284 DOI: 10.1111/j.1460-9568.2010.07109.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The motor symptoms of Parkinson's disease (PD) are commonly attributed to striatal dopamine loss, but reduced dopamine innervation of basal ganglia output nuclei, the internal globus pallidus (GPi) and the substantia nigra pars reticulata (SNr) may also contribute to symptoms and signs of PD. Both structures express dopamine D1 and D5 receptors under normal conditions, and we have recently demonstrated that their local activation reduces neuronal discharge rates and enhances bursts and oscillatory activity in both nuclei of normal monkeys [M.A. Kliem et al. (2007)J. Neurophysiol., 89, 1489-1500]. Here, we determined the ultrastructural localization and function of D1-like receptors in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated parkinsonian monkeys. In both normal and MPTP-treated monkeys, most of the D1 and D5 receptor immunoreactivity was associated with unmyelinated axons, but we also found significant postsynaptic D5 receptor immunostaining in dendrites of GPi and SNr neurons. A significant proportion of axonal D1 immunostaining was bound to the plasma membrane in both normal and MPTP-treated monkeys. Local microinjections of the D1/D5 receptor agonist SKF82958 significantly reduced discharge rates in GPi and SNr neurons, while they increased burst firing and oscillatory activity in the 3-15-Hz band in SNr, but not in GPi, of parkinsonian monkeys. Together with our recent findings from normal monkeys, these data provide evidence that functional D1/D5 receptors are expressed in GPi and SNr in both normal and parkinsonian states, and that their activation by endogenous dopamine (under normal conditions) or dopamine receptor agonists (in parkinsonism) may regulate basal ganglia outflow.
Collapse
Affiliation(s)
- Michele A Kliem
- Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA
| | | | | | | | | |
Collapse
|
39
|
Cass WA, Peters LE. Neurturin protects against 6-hydroxydopamine-induced reductions in evoked dopamine overflow in rat striatum. Neurochem Int 2010; 57:540-6. [PMID: 20615442 DOI: 10.1016/j.neuint.2010.06.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Revised: 06/25/2010] [Accepted: 06/28/2010] [Indexed: 11/17/2022]
Abstract
Neurturin (NTN), a member of the glial cell line-derived neurotrophic factor (GDNF) family, has substantial effects on normal and lesioned nigrostriatal dopamine systems. However, its ability to protect against toxin-induced loss of striatal dopamine release has not been previously reported. The goal of the present study was to determine if NTN could protect against 6-hydroxydopamine (6-OHDA)-induced reductions in striatal dopamine overflow and tissue levels of dopamine and to compare the effects of NTN with those of GDNF. Male Fischer-344 rats were given a single injection of vehicle, or 5 microg NTN or GDNF, into the right striatum. The following day the animals were given a single injection of 12 microg 6-OHDA into the striatum at the same site where the trophic factor was injected. Microdialysis experiments conducted three weeks later indicated that the 6-OHDA decreased basal levels of dopamine and metabolites in the lesioned striatum compared to the contralateral striatum, and NTN was able to partially protect against the 6-OHDA-induced reductions. Injection of NTN one day prior to 6-OHDA also led to significant protection against loss of both potassium- and amphetamine-evoked overflow of dopamine. The NTN treatments partially protected against 6-OHDA-induced reductions in striatal tissue levels of dopamine and completely protected against loss of nigral dopamine content. The protective effects of NTN were similar in magnitude to those of GDNF. These results support that within the experimental parameters used in this study, NTN is as effective as GDNF in protecting against the dopamine-depleting effects of intrastriatal 6-OHDA.
Collapse
Affiliation(s)
- Wayne A Cass
- Department of Anatomy and Neurobiology, University of Kentucky College of Medicine, Lexington, KY 40536-0298, USA.
| | | |
Collapse
|
40
|
Saiki H, Hayashi T, Takahashi R, Takahashi J. Objective and quantitative evaluation of motor function in a monkey model of Parkinson's disease. J Neurosci Methods 2010; 190:198-204. [DOI: 10.1016/j.jneumeth.2010.05.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Revised: 05/02/2010] [Accepted: 05/11/2010] [Indexed: 11/24/2022]
|
41
|
Opazo F, Schulz JB, Falkenburger BH. PKC links Gq-coupled receptors to DAT-mediated dopamine release. J Neurochem 2010; 114:587-96. [DOI: 10.1111/j.1471-4159.2010.06788.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
42
|
Navailles S, Bioulac B, Gross C, De Deurwaerdère P. Serotonergic neurons mediate ectopic release of dopamine induced by L-DOPA in a rat model of Parkinson's disease. Neurobiol Dis 2010; 38:136-43. [PMID: 20096781 DOI: 10.1016/j.nbd.2010.01.012] [Citation(s) in RCA: 151] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Accepted: 01/14/2010] [Indexed: 11/28/2022] Open
Abstract
Benefit and motor side effects of l-DOPA in Parkinson's disease have been related to dopamine transmission in the striatum. However, the putative involvement of serotonergic neurons in the dopaminergic effects of l-DOPA suggests that the striatum is not a preferential target of l-DOPA. By using microdialysis in a rat model of Parkinson's disease, we found that l-DOPA (3-100 mg/kg) increased dopamine extracellular levels monitored simultaneously in four brain regions receiving serotonergic innervation: striatum, substantia nigra, hippocampus, prefrontal cortex. The increase was regionally similar at the lowest dose and 2-3 times stronger in the striatum at higher doses. Citalopram, a serotonin reuptake blocker, or the destruction of serotonergic fibers by 5,7-dihydroxytryptamine impaired l-DOPA-induced dopamine release in all regions. These data demonstrate that l-DOPA induces an ectopic release of dopamine due to serotonergic neurons. The new pattern of dopamine transmission created by l-DOPA may contribute to the benefit and side effects of l-DOPA.
Collapse
Affiliation(s)
- Sylvia Navailles
- Université de Bordeaux, Unité Mixte de Recherche Centre National de la Recherche Scientifique 5227, Centre Hospitalier Universitaire de Bordeaux, 33076 Bordeaux cedex, France
| | | | | | | |
Collapse
|
43
|
Salvatore MF, Pruett BS, Spann SL, Dempsey C. Aging reveals a role for nigral tyrosine hydroxylase ser31 phosphorylation in locomotor activity generation. PLoS One 2009; 4:e8466. [PMID: 20037632 PMCID: PMC2791868 DOI: 10.1371/journal.pone.0008466] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Accepted: 11/29/2009] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Tyrosine hydroxylase (TH) regulates dopamine (DA) bioavailability. Its product, L-DOPA, is an established treatment for Parkinson's disease (PD), suggesting that TH regulation influences locomotion. Site-specific phosphorylation of TH at ser31 and ser40 regulates activity. No direct evidence shows that ser40 phosphorylation is the dominating mechanism of regulating TH activity in vivo, and physiologically-relevant stimuli increase L-DOPA biosynthesis independent of ser40 phosphorylation. Significant loss of locomotor activity occurs in aging as in PD, despite less loss of striatal DA or TH in aging compared to the loss associated with symptomatic PD. However, in the substantia nigra (SN), there is equivalent loss of DA or TH in aging and at the onset of PD symptoms. Growth factors increase locomotor activity in both PD and aging models and increase DA bioavailability and ser31 TH phosphorylation in SN, suggesting that ser31 TH phosphorylation status in the SN, not striatum, regulates DA bioavailability necessary for locomotor activity. METHODOLOGY AND PRINCIPAL FINDINGS We longitudinally characterized locomotor activity in young and older Brown-Norway Fischer 344 F(1) hybrid rats (18 months apart in age) at two time periods, eight months apart. The aged group served as an intact and pharmacologically-naïve source of deficient locomotor activity. Following locomotor testing, we analyzed DA tissue content, TH protein, and TH phosphorylation in striatum, SN, nucleus accumbens, and VTA. Levels of TH protein combined with ser31 phosphorylation alone reflected inherent differences in DA levels among the four regions. Measures strictly pertaining to locomotor activity initiation significantly correlated to DA content only in the SN. Nigral TH protein and ser31 phosphorylation together significantly correlated to test subject's maximum movement number, horizontal activity, and duration. CONCLUSIONS/SIGNIFICANCE Together, these results show ser31 TH phosphorylation regulates DA bioavailability in intact neuropil, its status in the SN may regulate locomotor activity generation, and it may represent an accurate target for treating locomotor deficiency. They also show that neurotransmitter regulation in cell body regions can mediate behavioral outcomes and that ser31 TH phosphorylation plays a role in behaviors dependent upon catecholamines, such as dopamine.
Collapse
Affiliation(s)
- Michael F Salvatore
- Department of Pharmacology, Toxicology, and Neuroscience, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA.
| | | | | | | |
Collapse
|
44
|
Motor activity-induced dopamine release in the substantia nigra is regulated by muscarinic receptors. Exp Neurol 2009; 221:251-9. [PMID: 19944096 DOI: 10.1016/j.expneurol.2009.11.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2009] [Revised: 11/10/2009] [Accepted: 11/15/2009] [Indexed: 11/20/2022]
Abstract
Nigro-striatal neurons release dopamine not only from their axon terminals in the striatum, but also from somata and dendrites in the substantia nigra. Somatodendritic dopamine release in the substantia nigra can facilitate motor function by mechanisms that may act independently of axon terminal dopamine release in the striatum. The dopamine neurons in the substantia nigra receive a cholinergic input from the pedunculopontine nucleus. Despite recent efforts to introduce this nucleus as a potential target for deep brain stimulation to treat motor symptoms in Parkinson's disease; and the well-known antiparkinsonian effects of anticholinergic drugs; the cholinergic influence on somatodendritic dopamine release is not well understood. The aim of this study was to investigate the possible regulation of locomotor-induced dopamine release in the substantia nigra by endogenous acetylcholine release. In intact and 6-OHDA hemi-lesioned animals alike, the muscarinic antagonist scopolamine, when perfused in the substantia nigra, amplified the locomotor-induced somatodendritic dopamine release to approximately 200% of baseline, compared to 120-130% of baseline in vehicle-treated animals. A functional importance of nigral muscarinic receptor activation was demonstrated in hemi-lesioned animals, where motor performance was significantly improved by scopolamine to 82% of pre-lesion performance, as compared to 56% in vehicle-treated controls. The results indicate that muscarinic activity in the substantia nigra is of functional importance in an animal Parkinson's disease model, and strengthen the notion that nigral dopaminergic regulation of motor activity/performance is independent of striatal dopamine release.
Collapse
|
45
|
Kim Y, Park MK, Chung S. Regulation of somatodendritic dopamine release by corticotropin-releasing factor via the inhibition of voltage-operated Ca2+ channels. Neurosci Lett 2009; 465:31-5. [DOI: 10.1016/j.neulet.2009.08.066] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Revised: 08/21/2009] [Accepted: 08/28/2009] [Indexed: 10/20/2022]
|
46
|
Levodopa enhances synaptic plasticity in the substantia nigra pars reticulata of Parkinson's disease patients. Brain 2008; 132:309-18. [DOI: 10.1093/brain/awn322] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
47
|
Guatteo E, Cucchiaroni ML, Sebastianelli L, Bernardi G, Mercuri NB. The midbrain slice preparation. An in vitro model to select potential anti-parkinsonian drugs? Parkinsonism Relat Disord 2008; 14 Suppl 2:S150-3. [DOI: 10.1016/j.parkreldis.2008.04.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
48
|
Rocha MA, Crockett DP, Wong LY, Richardson JR, Sonsalla PK. Na(+)/H(+) exchanger inhibition modifies dopamine neurotransmission during normal and metabolic stress conditions. J Neurochem 2008; 106:231-43. [PMID: 18363831 DOI: 10.1111/j.1471-4159.2008.05355.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Na(+)/H(+) exchanger (NHE) proteins are involved in intracellular pH and volume regulation and may indirectly influence neurotransmission. The abundant NHE isoform 1 (NHE1) has also been linked to brain cell damage during metabolic stress. It is not known, however, whether NHE1 or other NHE isoforms play a role in striatal dopamine (DA) neurotransmission under normal or metabolic stress conditions. Our study tested the hypothesis that NHE inhibition with cariporide mesilate (HOE-642) modifies striatal DA overflow and DAergic terminal damage in mice caused by the mitochondrial inhibitor malonate. We also explored the expression of NHE1-5 in the striatum and substantia nigra. Reverse microdialysis of HOE-642 elicited a transient elevation followed by a reduction in DA overflow accompanied by a decline in striatal DA content. HOE-642 pre-treatment diminished the malonate-induced DA overflow without reducing the intensity of the metabolic stress or subsequent DAergic axonal damage. Although NHE isoforms 1-5 are expressed in the striatum and midbrain, NHE1 protein was not co-located on nigrostriatal DAergic neurons. The absence of NHE1 co-location on DAergic neurons suggests that the effects of HOE-642 on striatal DA overflow are either mediated via NHE1 located on other cell types or that HOE-642 is acting through multiple NHE isoforms.
Collapse
Affiliation(s)
- Marcelo A Rocha
- Department of Neurology, UMDNJ-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA
| | | | | | | | | |
Collapse
|
49
|
Abstract
Information flow through neurones was historically considered to be linear, with dendrites receiving information from incoming synaptic terminals, the soma processing the information and the axon carrying it to the terminal that synapses upon another cell or end organ. However, recent studies have shown that dendrites can release transmitters themselves, and thereby communicate with neighbouring structures, whether these are adjacent neurones or incoming synapses. Due to their anatomical features, the magnocellular vasopressin and oxytocin containing neurones of the hypothalamic supraoptic and paraventricular nuclei and the dopamine neurones of the substantia nigra have revealed important aspects of dendritic function including mechanisms of dendritic transmitter release.
Collapse
Affiliation(s)
- F Bergquist
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK
| | | |
Collapse
|
50
|
Kliem MA, Maidment NT, Ackerson LC, Chen S, Smith Y, Wichmann T. Activation of nigral and pallidal dopamine D1-like receptors modulates basal ganglia outflow in monkeys. J Neurophysiol 2007; 98:1489-500. [PMID: 17634344 DOI: 10.1152/jn.00171.2007] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Studies of the effects of dopamine in the basal ganglia have focused on the striatum, whereas the functions of dopamine released in the internal pallidal segment (GPi) or in the substantia nigra pars reticulata (SNr) have received less attention. Anatomic and biochemical investigations have demonstrated the presence of dopamine D1-like receptors (D1LRs) in GPi and SNr, which are primarily located on axons and axon terminals of the GABAergic striatopallidal and striatonigral afferents. Our experiments assessed the effects of D1LR ligands in GPi and SNr on local gamma-aminobutyric acid (GABA) levels and neuronal activity in these nuclei in rhesus monkeys. Microinjections of the D1LR receptor agonist SKF82958 into GPi and SNr significantly reduced discharge rates in GPi and SNr, whereas injections of the D1LR antagonist SCH23390 increased firing in the majority of GPi neurons. D1LR activation also increased bursting and oscillations in neuronal discharge in the 3- to 15-Hz band in both structures, whereas D1LR blockade had the opposite effects in GPi. Microdialysis measurements of GABA concentrations in GPi and SNr showed that the D1LR agonist increased the level of the transmitter. Both findings are compatible with the hypothesis that D1LR activation leads to GABA release from striatopallidal or striatonigral afferents, which may secondarily reduce firing of basal ganglia output neurons. The antagonist experiments suggest that a dopaminergic "tone" exists in GPi. Our results support the finding that D1LR activation may have powerful effects on GPi and SNr neurons and may mediate some of the effects of dopamine replacement therapies in Parkinson's disease.
Collapse
Affiliation(s)
- Michele A Kliem
- Yerkes National Primate Center, Emory University, School of Medicine, 954 Gatewood Road, Atlanta, GA 30322, USA
| | | | | | | | | | | |
Collapse
|