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Godoy R, Macedo AB, Gervazio KY, Ribeiro LR, Lima JLF, Salvadori MGSS. Effects of ortho-eugenol on anxiety, working memory and oxidative stress in mice. BRAZ J BIOL 2023; 83:e271785. [PMID: 37610945 DOI: 10.1590/1519-6984.271785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Accepted: 06/21/2023] [Indexed: 08/25/2023] Open
Abstract
Ortho-eugenol is a synthetic derivative from eugenol, the major compound of clove essential oil, which has demonstrated antidepressant and antinociceptive effects in pioneering studies. Additionally, its effects appear to be dependent on the noradrenergic and dopaminergic systems. Depression and anxiety disorders are known to share a great overlap in their pathophysiology, and many drugs are effective in the treatment of both diseases. Furthermore, high levels of anxiety are related to working memory deficits and increased oxidative stress. Thus, in this study we investigated the effects of acute treatment of ortho-eugenol, at 50, 75 and 100 mg/kg, on anxiety, working memory and oxidative stress in male Swiss mice. Our results show that the 100 mg/kg dose increased the number of head-dips and reduced the latency in the hole-board test. The 50 mg/kg dose reduced malondialdehyde levels in the prefrontal cortex and the number of Y-maze entries compared to the MK-801-induced hyperlocomotion group. All doses reduced nitrite levels in the hippocampus. It was also possible to assess a statistical correlation between the reduction of oxidative stress and hyperlocomotion after the administration of ortho-eugenol. However, acute treatment was not able to prevent working memory deficits. Therefore, the present study shows that ortho-eugenol has an anxiolytic and antioxidant effect, and was able to prevent substance-induced hyperlocomotion. Our results contribute to the elucidation of the pharmacological profile of ortho-eugenol, as well as to direct further studies that seek to investigate its possible clinical applications.
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Affiliation(s)
- R Godoy
- Universidade Federal da Paraíba, Instituto de Pesquisa em Fármacos e Medicamentos, Laboratório de Psicofarmacologia, João Pessoa, PB, Brasil
| | - A B Macedo
- Universidade Federal da Paraíba, Instituto de Pesquisa em Fármacos e Medicamentos, Laboratório de Psicofarmacologia, João Pessoa, PB, Brasil
| | - K Y Gervazio
- Universidade Federal da Paraíba, Instituto de Pesquisa em Fármacos e Medicamentos, Laboratório de Psicofarmacologia, João Pessoa, PB, Brasil
- Universidade Federal da Paraíba, Centro de Ciências da Saúde, Programa de Pós-graduação em Produtos Bioativos Naturais e Sintéticos - PgPNSB, João Pessoa, PB, Brasil
| | - L R Ribeiro
- Universidade Federal da Paraíba, Instituto de Pesquisa em Fármacos e Medicamentos, Laboratório de Psicofarmacologia, João Pessoa, PB, Brasil
| | - J L F Lima
- Universidade Federal da Paraíba, Instituto de Pesquisa em Fármacos e Medicamentos, Laboratório de Psicofarmacologia, João Pessoa, PB, Brasil
- Universidade Federal da Paraíba, Centro de Ciências da Saúde, Programa de Pós-graduação em Produtos Bioativos Naturais e Sintéticos - PgPNSB, João Pessoa, PB, Brasil
| | - M G S S Salvadori
- Universidade Federal da Paraíba, Instituto de Pesquisa em Fármacos e Medicamentos, Laboratório de Psicofarmacologia, João Pessoa, PB, Brasil
- Universidade Federal da Paraíba, Centro de Ciências da Saúde, Programa de Pós-graduação em Produtos Bioativos Naturais e Sintéticos - PgPNSB, João Pessoa, PB, Brasil
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2
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Żakowski W, Zawistowski P. Neurochemistry of the mammillary body. Brain Struct Funct 2023; 228:1379-1398. [PMID: 37378855 PMCID: PMC10335970 DOI: 10.1007/s00429-023-02673-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 06/19/2023] [Indexed: 06/29/2023]
Abstract
The mammillary body (MB) is a component of the extended hippocampal system and many studies have shown that its functions are vital for mnemonic processes. Together with other subcortical structures, such as the anterior thalamic nuclei and tegmental nuclei of Gudden, the MB plays a crucial role in the processing of spatial and working memory, as well as navigation in rats. The aim of this paper is to review the distribution of various substances in the MB of the rat, with a description of their possible physiological roles. The following groups of substances are reviewed: (1) classical neurotransmitters (glutamate and other excitatory transmitters, gamma-aminobutyric acid, acetylcholine, serotonin, and dopamine), (2) neuropeptides (enkephalins, substance P, cocaine- and amphetamine-regulated transcript, neurotensin, neuropeptide Y, somatostatin, orexins, and galanin), and (3) other substances (calcium-binding proteins and calcium sensor proteins). This detailed description of the chemical parcellation may facilitate a better understanding of the MB functions and its complex relations with other structures of the extended hippocampal system.
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Affiliation(s)
- Witold Żakowski
- Department of Animal and Human Physiology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308, Gdańsk, Poland.
| | - Piotr Zawistowski
- Department of Animal and Human Physiology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308, Gdańsk, Poland
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3
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Khalsa SS, Victor TA, Kuplicki R, Yeh HW, Vanover KE, Paulus MP, Davis RE. Single doses of a highly selective inhibitor of phosphodiesterase 1 (lenrispodun) in healthy volunteers: a randomized pharmaco-fMRI clinical trial. Neuropsychopharmacology 2022; 47:1844-1853. [PMID: 35488084 PMCID: PMC9372139 DOI: 10.1038/s41386-022-01331-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 04/11/2022] [Accepted: 04/15/2022] [Indexed: 11/09/2022]
Abstract
Lenrispodun is a potent and highly selective inhibitor of phosphodiesterase (PDE) type 1, which is thought to prolong intracellular second messenger signaling within cortical and subcortical dopaminergic brain regions. This is the first study of a PDE1 inhibitor in healthy volunteers using behavioral and neuroimaging approaches to examine its effects on neural targets and to provide a safety and tolerability assessment. The primary objectives were to determine whether lenrispodun induces changes in BOLD fMRI signals in the inferior frontal gyrus (IFG) during the stop signal task, and the dorsal anterior insula (dAI) during the extinction phase of a fear conditioning/extinction task. Using a double-blind, placebo-controlled, within-subjects design, 26 healthy individuals (22 completed all fMRI sessions) received in random order a single oral dose of placebo, lenrispodun 1.0 milligram (mg) or lenrispodun 10.0 mg and completed several tasks in the scanner including the stop signal (n = 24) and fear conditioning/extinction tasks (n = 22). Prespecified region-of-interest analyses for the IFG and dAI were computed using linear mixed models. Lenrispodun induced increases in IFG activity during the stop signal task at 1.0 mg (Cohen's d = 0.63) but not 10.0 mg (Cohen's d = 0.07) vs. placebo. Lenrispodun did not induce changes in dAI activity during fear extinction at either dose. Exploratory outcomes revealed changes in cardiac interoception. Lenrispodun administration was well-tolerated. These results provide evidence that 1.0 mg lenrispodun selectively improved neural inhibitory control without altering fear extinction processing. Future investigations should determine whether lenrispodun improves inhibitory control in target populations such as individuals with attention deficit hyperactivity disorder. Trial registration: ClinicalTrials.gov identifier: NCT03489772.
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Affiliation(s)
- Sahib S Khalsa
- Laureate Institute for Brain Research, Tulsa, OK, USA.
- Oxley College of Health Sciences, The University of Tulsa, Tulsa, OK, USA.
| | | | | | - Hung-Wen Yeh
- Laureate Institute for Brain Research, Tulsa, OK, USA
- Health Services and Outcomes Research, Children's Mercy Hospital, Kansas City, MO, USA
- School of Medicine, University of Missouri-Kansas City, Kansas City, MO, USA
| | | | - Martin P Paulus
- Laureate Institute for Brain Research, Tulsa, OK, USA
- Oxley College of Health Sciences, The University of Tulsa, Tulsa, OK, USA
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4
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Flace P, Livrea P, Basile GA, Galletta D, Bizzoca A, Gennarini G, Bertino S, Branca JJV, Gulisano M, Bianconi S, Bramanti A, Anastasi G. The Cerebellar Dopaminergic System. Front Syst Neurosci 2021; 15:650614. [PMID: 34421548 PMCID: PMC8375553 DOI: 10.3389/fnsys.2021.650614] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 05/04/2021] [Indexed: 12/04/2022] Open
Abstract
In the central nervous system (CNS), dopamine (DA) is involved in motor and cognitive functions. Although the cerebellum is not been considered an elective dopaminergic region, studies attributed to it a critical role in dopamine deficit-related neurological and psychiatric disorders [e.g., Parkinson's disease (PD) and schizophrenia (SCZ)]. Data on the cerebellar dopaminergic neuronal system are still lacking. Nevertheless, biochemical studies detected in the mammalians cerebellum high dopamine levels, while chemical neuroanatomy studies revealed the presence of midbrain dopaminergic afferents to the cerebellum as well as wide distribution of the dopaminergic receptor subtypes (DRD1-DRD5). The present review summarizes the data on the cerebellar dopaminergic system including its involvement in associative and projective circuits. Furthermore, this study also briefly discusses the role of the cerebellar dopaminergic system in some neurologic and psychiatric disorders and suggests its potential involvement as a target in pharmacologic and non-pharmacologic treatments.
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Affiliation(s)
- Paolo Flace
- Medical School, University of Bari ‘Aldo Moro', Bari, Italy
| | | | - Gianpaolo Antonio Basile
- Department of Biomedical, Dental Sciences and Morphological and Functional Images, University of Messina, Messina, Italy
| | - Diana Galletta
- Unit of Psychiatry and Psychology, Federico II University Hospital, Naples, Italy
| | - Antonella Bizzoca
- Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari “Aldo Moro”, Bari, Italy
| | - Gianfranco Gennarini
- Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari “Aldo Moro”, Bari, Italy
| | - Salvatore Bertino
- Department of Biomedical, Dental Sciences and Morphological and Functional Images, University of Messina, Messina, Italy
| | | | - Massimo Gulisano
- Department of Experimental and Clinical Medicine, University of Firenze, Firenze, Italy
| | - Simona Bianconi
- Physical, Rehabilitation Medicine and Sport Medicine Unit, University Hospital “G. Martino”, Messina, Italy
| | - Alessia Bramanti
- Scientific Institute for Research, Hospitalization and Health Care IRCCS “Centro Neurolesi Bonino Pulejo”, Messina, Italy
| | - Giuseppe Anastasi
- Department of Biomedical, Dental Sciences and Morphological and Functional Images, University of Messina, Messina, Italy
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5
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Nouri K, Anooshe M, Karimi-Haghighi S, Mousavi Z, Haghparast A. Involvement of Hippocampal D1-Like Dopamine Receptors in the Inhibitory Effect of Cannabidiol on Acquisition and Expression of Methamphetamine-Induced Conditioned Place Preference. Neurochem Res 2021; 46:2008-2018. [PMID: 33993443 DOI: 10.1007/s11064-021-03350-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 04/22/2021] [Accepted: 05/12/2021] [Indexed: 12/21/2022]
Abstract
Cannabidiol (CBD) is a non-psychotomimetic compound with strong potential to decrease the psychostimulant's rewarding effect with unclear receptors. Furthermore, as a part of the reward circuit, the hippocampus plays a crucial role in regulating the reward properties of drugs as determined by conditioned place preference (CPP). In the current research, CPP was used to evaluate the role of intra-CA1 microinjection of D1-like dopamine receptor antagonists in CBD's inhibitory effect on the acquisition and expression phases of methamphetamine (METH). Animals were treated by METH (1 mg/kg; sc) in a five-day schedule to induce CPP. To find out the impact of D1-like dopamine receptor antagonist, SCH23390, in the CA1 on the inhibitory influence of CBD on the acquisition of METH, the rats received intra-CA1 administration of SCH23390 (0.25, 1, and 4 µg/0.5 µl) following ICV treatment of CBD (10 µg/5 µl) over conditioning phase of METH. Furthermore, animals were given SCH23390 in the CA1 ensuing ICV microinjection of CBD (50 µg/5 µl) in the expression phase of METH to rule out the influence of SCH23390 on the suppressive effect of CBD on the expression of METH CPP. Intra-CA1 microinjection of SCH23390 abolished CBD's suppressive impact on both METH-induced CPP phases without any side effect on the locomotion. The current research disclosed that CBD inhibited the rewarding characteristic of METH via D1-like dopamine receptors in the CA1 region of the hippocampus.
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Affiliation(s)
- Kiana Nouri
- Pharmacology and Toxicology Department, Faculty of Pharmacy and Pharmaceutical Sciences, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Mahsa Anooshe
- Pharmacology and Toxicology Department, Faculty of Pharmacy and Pharmaceutical Sciences, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | | | - Zahra Mousavi
- Pharmacology and Toxicology Department, Faculty of Pharmacy and Pharmaceutical Sciences, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Abbas Haghparast
- Neuroscience Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, 19615-1178, Tehran, Iran.
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6
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Palomero-Gallagher N, Zilles K. Cyto- and receptor architectonic mapping of the human brain. HANDBOOK OF CLINICAL NEUROLOGY 2018; 150:355-387. [PMID: 29496153 DOI: 10.1016/b978-0-444-63639-3.00024-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Mapping of the human brain is more than the generation of an atlas-based parcellation of brain regions using histologic or histochemical criteria. It is the attempt to provide a topographically informed model of the structural and functional organization of the brain. To achieve this goal a multimodal atlas of the detailed microscopic and neurochemical structure of the brain must be registered to a stereotaxic reference space or brain, which also serves as reference for topographic assignment of functional data, e.g., functional magnet resonance imaging, electroencephalography, or magnetoencephalography, as well as metabolic imaging, e.g., positron emission tomography. Although classic maps remain pioneering steps, they do not match recent concepts of the functional organization in many regions, and suffer from methodic drawbacks. This chapter provides a summary of the recent status of human brain mapping, which is based on multimodal approaches integrating results of quantitative cyto- and receptor architectonic studies with focus on the cerebral cortex in a widely used reference brain. Descriptions of the methods for observer-independent and statistically testable cytoarchitectonic parcellations, quantitative multireceptor mapping, and registration to the reference brain, including the concept of probability maps and a toolbox for using the maps in functional neuroimaging studies, are provided.
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Affiliation(s)
- Nicola Palomero-Gallagher
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany; Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH, Aachen, Germany
| | - Karl Zilles
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany; Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH, Aachen, Germany; JARA-BRAIN, Jülich-Aachen Research Alliance, Jülich, Germany.
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7
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King DR, de Chastelaine M, Rugg MD. Recollection-related increases in functional connectivity across the healthy adult lifespan. Neurobiol Aging 2018; 62:1-19. [PMID: 29101898 PMCID: PMC5753578 DOI: 10.1016/j.neurobiolaging.2017.09.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 09/20/2017] [Accepted: 09/23/2017] [Indexed: 12/24/2022]
Abstract
In young adults, recollection-sensitive brain regions exhibit enhanced connectivity with a widely distributed set of other regions during successful versus unsuccessful recollection, and the magnitude of connectivity change correlates with individual differences in recollection accuracy. Here, we examined whether recollection-related changes in connectivity and their relationship with performance varied across samples of young, middle-aged, and older adults. Psychophysiological interaction analyses identified recollection-related increases in connectivity both with recollection-sensitive seed regions and among regions distributed throughout the whole brain. The seed-based approach failed to identify age-related differences in recollection-related connectivity change. However, the whole-brain analysis revealed a number of age-related effects. Numerous pairs of regions exhibited a main effect of age on connectivity change, mostly due to decreased change with increasing age. After controlling for recollection accuracy, however, these effects of age were for the most part no longer significant, and those effects that were detected now reflected age-related increases in connectivity change. A subset of pairs of regions also exhibited an age by performance interaction, driven mostly by a weaker relationship between connectivity change and recollection accuracy with increasing age. We conjecture that these effects reflect age-related differences in neuromodulation.
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Affiliation(s)
- Danielle R King
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA.
| | - Marianne de Chastelaine
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA
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8
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Abstract
Cortical plasticity refers to flexible and long-lasting changes in neuronal circuitry and information processing, which is caused by learning and experience. Although cortical plasticity can be observed in every cortex of the brain, the plasticity of the prefrontal cortex (PFC) is particularly important because the PFC is involved in various cognitive functions, and its plasticity could lead to adaptive changes in the use of other brain regions. Cortical plasticity occurs at several levels, from functional molecules to the organization of large areas of the brain. Here, the authors focus mainly on the development and remodeling of the functional and structural organization of the primate PFC. They discuss how the columnar modules of the PFC develop in the immature brain, how these modules form a “cognitive field” that is responsible for a specific cognitive function, how the cognitive field could be reorganized by training in the mature brain, and how monoaminergic systems contribute to these various levels of plasticity. They suggest that monoaminergic systems, especially the dopaminergic system, are involved in various levels of cortical plasticity, such as behavioral learning and learning-dependent cortical remodeling, thereby contributing to the reorganization of the cognitive field in the primate PFC. NEUROSCIENTIST 13(3):229—240, 2007.
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Affiliation(s)
- Satoko Kuboshima-Amemori
- Laboratory of Cognitive Neurobiology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
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9
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Nakajima S, Caravaggio F, Boileau I, Chung JK, Plitman E, Gerretsen P, Wilson AA, Houle S, Mamo DC, Graff-Guerrero A. Lack of age-dependent decrease in dopamine D3 receptor availability: a [(11)C]-(+)-PHNO and [(11)C]-raclopride positron emission tomography study. J Cereb Blood Flow Metab 2015; 35:1812-8. [PMID: 26058690 PMCID: PMC4635236 DOI: 10.1038/jcbfm.2015.129] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 03/17/2015] [Accepted: 04/23/2015] [Indexed: 02/05/2023]
Abstract
Positron emission tomography with antagonist radiotracers has showed that striatal dopamine D2/3 receptor (D2/3R) availability decreases with age. However, no study has specifically assessed whether D2/3R availability decreases with age in healthy persons as measured with agonist radiotracers. Moreover, it is unknown whether D3R availability changes with age in healthy humans. Thus, we explored the relationship between age and D2/3R availability in healthy humans using the D3 receptor (D3R)-preferential agonist radiotracer [(11)C]-(+)-PHNO (n=72, mean±s.d. age=40±15, range=18 to 73) and the antagonist [(11)C]-Raclopride (n=70, mean±s.d. age =40±14, range=18 to 73) (both, n=33). The contribution of D3R to the [(11)C]-(+)-PHNO signal varies across regions of interest; the substantia nigra and hypothalamus represent D3R-specific regions, the ventral pallidum, globus pallidus, and ventral striatum represent D2/3R-mixed regions, and the caudate and putamen represent D2 receptor (D2R)-specific regions. With [(11)C]-(+)-PHNO, a negative correlation was observed between age and nondisplaceable binding potential (BPND) in the caudate (r(70)=-0.32, P=0.005). No correlations were observed in the other regions. With [(11)C]-Raclopride, negative correlations were observed between age and BPND in the caudate (r(68)=-0.50, P<0.001), putamen (r(68)=-0.41, P<0.001), and ventral striatum (r(68)=-0.43, P<0.001). In conclusion, in contrast with the age-dependent decrease in D2R availability, these findings suggest that D3R availability does not change with age.
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Affiliation(s)
- Shinichiro Nakajima
- Multimodal Imaging Group-Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Geriatric Mental Health Division, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Department of Neuropsychiatry, School of Medicine, Keio University, Tokyo, Japan
| | - Fernando Caravaggio
- Multimodal Imaging Group-Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Isabelle Boileau
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Centre for Addiction and Mental Health, Campbell Research Institute, Toronto, Ontario, Canada
| | - Jun K Chung
- Multimodal Imaging Group-Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Eric Plitman
- Multimodal Imaging Group-Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Philip Gerretsen
- Multimodal Imaging Group-Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Geriatric Mental Health Division, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Alan A Wilson
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.,Centre for Addiction and Mental Health, Campbell Research Institute, Toronto, Ontario, Canada
| | - Sylvain Houle
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Centre for Addiction and Mental Health, Campbell Research Institute, Toronto, Ontario, Canada
| | - David C Mamo
- Multimodal Imaging Group-Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Geriatric Mental Health Division, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Department of Psychiatry, University of Malta, Valletta, Malta
| | - Ariel Graff-Guerrero
- Multimodal Imaging Group-Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Geriatric Mental Health Division, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Centre for Addiction and Mental Health, Campbell Research Institute, Toronto, Ontario, Canada
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10
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Karimi M, Moerlein SM, Videen TO, Su Y, Flores HP, Perlmutter JS. Striatal dopamine D1-like receptor binding is unchanged in primary focal dystonia. Mov Disord 2013; 28:2002-6. [PMID: 24151192 PMCID: PMC4086787 DOI: 10.1002/mds.25720] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 09/19/2013] [Accepted: 09/23/2013] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Multiple studies have demonstrated decreases in striatal D2-like (D2, D3) radioligand binding in primary focal dystonias. Although most investigations have focused on D2-specific receptors (D2R), a recent study suggests that the decreased D2-like binding may be due to a D3-specific (D3R) abnormality. However, only limited data exist on the role of D1-specific receptors (D1R) and the D1R-mediated pathways within basal ganglia in dystonia. Metabolic positron emission tomography (PET) data in primary generalized dystonia suggest resting state over activity in the D1R-mediated direct pathway, leading to excessive disinhibition of motor cortical areas. This work investigated whether striatal D1-like receptors are affected in primary focal dystonias. METHODS Striatal-specific (caudate and putamen) binding of the D1-like radioligand [(11)C]NNC 112 was measured using PET in 19 patients with primary focal dystonia (cranial, cervical, or arm) and 18 controls. RESULTS No statistically significant difference was detected in striatal D1-like binding between the two groups. The study had 91% power to detect a 20% difference, indicating that false-negative results were unlikely. CONCLUSIONS Because [(11)C]NNC 112 has high affinity for D1-like receptors, very low affinity for D2-like receptors, and minimal sensitivity to endogenous dopamine levels, we conclude that D1-like receptor binding is not impaired in these primary focal dystonias.
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Affiliation(s)
- Morvarid Karimi
- Department of Neurology, Washington University School of Medicine, Saint Louis, Missouri, USA
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11
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Luciana M, Depue RA, Arbisi P, Leon A. Facilitation of working memory in humans by a d2 dopamine receptor agonist. J Cogn Neurosci 2013; 4:58-68. [PMID: 23967857 DOI: 10.1162/jocn.1992.4.1.58] [Citation(s) in RCA: 165] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Recent studies on the neurobiology of cognition have focused on the ability of the prefrontal cortex (PFC) to support processes of working memory, i.e, mnemonic processes by which information relevant for a correct response is temporarily maintained to be reevaluated or updated on a trial-by-trial basis. Of most recent interest is the role played by dopamine (DA) in spatial working memory processes of the principal sulcal region of the PFC. Although D1 DA receptors appear to modulate these mnemonic processes in monkeys, several lines of research suggest that D2 DA receptors could also be relevant to cognitive functions. Therefore, we assessed the effects of a specific D2 receptor agonist (bromocriptine) and placebo on visuospatial delayed response performance in human subjects. During delay periods of 0 or 8 sec, subjects were required to remember the spatial location of rapidly presented visual cues displayed in peripheral vision within a 360° circumference. The extent to which D2 receptor activation by bromocriptine facilitated working memory in the 8-sec delay condition relative to placebo performance was assessed. As a means of providing validation of bromocriptine's D2 receptor effect, maximum inhibition of prolactin (PRL) secretion, which is inhibited specifically by activation of D2 receptor sites, was determined. Additionally, tasks having no working memory component were administered to rule out nonspecific effects of bromocriptine on sensory, arousal, attentional, and motor factors. Results demonstrated a significant facilitatory effect of bromocriptine on spatial delayed response performance (i.e., 8-sec delay performance). Results could not be explained by nonspecific effects of bromocriptine. Thus, findings of this study suggest that spatial working memory is facilitated by D2 receptor activation. The role that DA may play in human cognitive processes is discussed within the larger theoretical framework of DA's general role in the facilitation of goal-directed behavior. In the case of cognition, DA may facilitate processes that serve to guide motivated behavior through complex environments.
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12
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Maejima T, Masseck OA, Mark MD, Herlitze S. Modulation of firing and synaptic transmission of serotonergic neurons by intrinsic G protein-coupled receptors and ion channels. Front Integr Neurosci 2013; 7:40. [PMID: 23734105 PMCID: PMC3661940 DOI: 10.3389/fnint.2013.00040] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 05/03/2013] [Indexed: 11/13/2022] Open
Abstract
Serotonergic neurons project to virtually all regions of the central nervous system and are consequently involved in many critical physiological functions such as mood, sexual behavior, feeding, sleep/wake cycle, memory, cognition, blood pressure regulation, breathing, and reproductive success. Therefore, serotonin release and serotonergic neuronal activity have to be precisely controlled and modulated by interacting brain circuits to adapt to specific emotional and environmental states. We will review the current knowledge about G protein-coupled receptors and ion channels involved in the regulation of serotonergic system, how their regulation is modulating the intrinsic activity of serotonergic neurons and its transmitter release and will discuss the latest methods for controlling the modulation of serotonin release and intracellular signaling in serotonergic neurons in vitro and in vivo.
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Affiliation(s)
- Takashi Maejima
- Department of Zoology and Neurobiology, Ruhr-University Bochum Bochum, Germany
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Sun J, Xu J, Cairns NJ, Perlmutter JS, Mach RH. Dopamine D1, D2, D3 receptors, vesicular monoamine transporter type-2 (VMAT2) and dopamine transporter (DAT) densities in aged human brain. PLoS One 2012; 7:e49483. [PMID: 23185343 PMCID: PMC3504049 DOI: 10.1371/journal.pone.0049483] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Accepted: 10/11/2012] [Indexed: 11/18/2022] Open
Abstract
The dopamine D(1), D(2), D(3) receptors, vesicular monoamine transporter type-2 (VMAT2), and dopamine transporter (DAT) densities were measured in 11 aged human brains (aged 77-107.8, mean: 91 years) by quantitative autoradiography. The density of D(1) receptors, VMAT2, and DAT was measured using [(3)H]SCH23390, [(3)H]dihydrotetrabenazine, and [(3)H]WIN35428, respectively. The density of D(2) and D(3) receptors was calculated using the D(3)-preferring radioligand, [(3)H]WC-10 and the D(2)-preferring radioligand [(3)H]raclopride using a mathematical model developed previously by our group. Dopamine D(1), D(2), and D(3) receptors are extensively distributed throughout striatum; the highest density of D(3) receptors occurred in the nucleus accumbens (NAc). The density of the DAT is 10-20-fold lower than that of VMAT2 in striatal regions. Dopamine D(3) receptor density exceeded D(2) receptor densities in extrastriatal regions, and thalamus contained a high level of D(3) receptors with negligible D(2) receptors. The density of dopamine D(1) linearly correlated with D(3) receptor density in the thalamus. The density of the DAT was negligible in the extrastriatal regions whereas the VMAT2 was expressed in moderate density. D(3) receptor and VMAT2 densities were in similar level between the aged human and aged rhesus brain samples, whereas aged human brain samples had lower range of densities of D(1) and D(2) receptors and DAT compared with the aged rhesus monkey brain. The differential density of D(3) and D(2) receptors in human brain will be useful in the interpretation of PET imaging studies in human subjects with existing radiotracers, and assist in the validation of newer PET radiotracers having a higher selectivity for dopamine D(2) or D(3) receptors.
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Affiliation(s)
- Jianjun Sun
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Jinbin Xu
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Nigel J. Cairns
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Joel S. Perlmutter
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Neurobiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Occupational Therapy, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Physical Therapy, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Robert H. Mach
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Cell Biology amd Physiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, United States of America
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Mishina M, Kimura Y, Naganawa M, Ishii K, Oda K, Sakata M, Toyohara J, Kobayashi S, Katayama Y, Ishiwata K. Differential effects of age on human striatal adenosine A₁ and A(2A) receptors. Synapse 2012; 66:832-9. [PMID: 22623181 DOI: 10.1002/syn.21573] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 05/01/2012] [Accepted: 05/14/2012] [Indexed: 01/19/2023]
Abstract
The aim of this study was to investigate the effect of age on the distribution of adenosine A₁ receptors (A₁Rs) and adenosine A(2A) receptors (A(2A)Rs) in the striatum of healthy subjects using PET imaging with 8-dicyclopropylmethyl-1-[¹¹C]methyl-3-propylxanthine ([¹¹C]MPDX) and [7-methyl-¹¹C]-(E)-8-(3,4,5-trimethoxystyryl)-1,3,7-trimethylxanthine ([¹¹C]TMSX), respectively. We recruited 8 young (22.0 ± 1.7 years) and 10 elderly (65.4 ± 7.6 years) volunteers to undergo [¹¹C]MPDX PET scanning, and 11 young (22.7 ± 2.7 years) and six elderly (60.7 ± 8.5 years) volunteers to undergo [¹¹C]TMSX PET scanning. A dynamic series of decay-corrected PET scans was performed for 60 min following injection of [¹¹C]MPDX or [¹¹C]TMSX. We calculated the binding potential (BP(ND) ) of [¹¹C]MPDX and distribution volume ratio (DVR) of [¹¹C]TMSX in the striatum. The BP(ND) of [¹¹C]MPDX was significantly lower in elderly than in young subjects, both in the putamen and head of the caudate nucleus. The BP(ND) was negatively correlated with age in both the putamen and the head of the caudate nucleus. However, no difference was found between the DVR of [¹¹C]TMSX in the striata of young and elderly subjects, nor was there a correlation between age and the DVR of [¹¹C]TMSX. The effect of age on the distribution of A₁Rs in the human striatum described herein is similar to previous reports of age-related decreases in dopamine D₁ and D₂ receptors. Unlike A₁Rs, however, this study suggests that the distribution of A(2A) Rs does not change with age.
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Affiliation(s)
- Masahiro Mishina
- The Second Department of Internal Medicine, Nippon Medical School, Bunkyo-Ku, Tokyo, Japan; Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Itabashi-Ku, Tokyo, Japan.
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Zeki S, Romaya JP. The brain reaction to viewing faces of opposite- and same-sex romantic partners. PLoS One 2010; 5:e15802. [PMID: 21209829 PMCID: PMC3013131 DOI: 10.1371/journal.pone.0015802] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Accepted: 11/24/2010] [Indexed: 11/19/2022] Open
Abstract
We pursued our functional magnetic resonance imaging (fMRI) studies of the neural correlates of romantic love in 24 subjects, half of whom were female (6 heterosexual and 6 homosexual) and half male (6 heterosexual and 6 homosexual). We compared the pattern of activity produced in their brains when they viewed the faces of their loved partners with that produced when they viewed the faces of friends of the same sex to whom they were romantically indifferent. The pattern of activation and de-activation was very similar in the brains of males and females, and heterosexuals and homosexuals. We could therefore detect no difference in activation patterns between these groups.
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Affiliation(s)
- Semir Zeki
- Wellcome Laboratory of Neurobiology, University College London, London, United Kingdom.
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Jucaite A, Forssberg H, Karlsson P, Halldin C, Farde L. Age-related reduction in dopamine D1 receptors in the human brain: from late childhood to adulthood, a positron emission tomography study. Neuroscience 2010; 167:104-10. [DOI: 10.1016/j.neuroscience.2010.01.034] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2009] [Revised: 01/19/2010] [Accepted: 01/19/2010] [Indexed: 12/01/2022]
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Zhang H, Han T, Yu CH, Rahman K, Qin LP, Peng C. Ameliorating effects of essential oil from Acori graminei rhizoma on learning and memory in aged rats and mice. J Pharm Pharmacol 2010; 59:301-9. [PMID: 17270083 DOI: 10.1211/jpp.59.2.0016] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Abstract
Although there are normal cognitive changes that take place as a person becomes older, ageing in humans is generally associated with a deterioration of cognitive performance, in particular of learning and memory. There are a number of herbal medicines that are reported to improve brain function and intelligence. In the present study, the ameliorating effects of an essential oil extracted from Acori graminei rhizoma on learning and memory in aged, dysmnesia rats and mice were determined using the step-down passive avoidance test and Y maze. Oral administration of the essential oil (0.02, 0.04 and 0.08 g kg−1) to rats for 30 days and to mice for 15 days improved the latency and number of errors in aged, dysmnesia rats and mice. The cerebral neurotransmitters in aged rats given the essential oil (0.02, 0.04, 0.08 g kg−1) for 30 days were also investigated, and increased levels of norepinephrine, dopamine and serotonin, and decreased levels of acetylcholinesterase activity were found. The results suggest that the essential oil improves cognitive function in aged animals possibly by increasing norepinephrine, dopamine and serotonin relative levels, and by decreasing the activity of acetylcholinesterase in the cerebra.
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Affiliation(s)
- Hong Zhang
- Department of Pharmacognosy, School of Pharmacy, Second Military Medical University, Shanghai 200433, China
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18
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Role of dopamine receptor mechanisms in the amygdaloid modulation of fear and anxiety: Structural and functional analysis. Prog Neurobiol 2010; 90:198-216. [DOI: 10.1016/j.pneurobio.2009.10.010] [Citation(s) in RCA: 185] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Revised: 06/05/2009] [Accepted: 10/09/2009] [Indexed: 11/18/2022]
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Düzel S, Münte TF, Lindenberger U, Bunzeck N, Schütze H, Heinze HJ, Düzel E. Basal forebrain integrity and cognitive memory profile in healthy aging. Brain Res 2010; 1308:124-36. [DOI: 10.1016/j.brainres.2009.10.048] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Revised: 10/16/2009] [Accepted: 10/16/2009] [Indexed: 01/03/2023]
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Düzel E, Bunzeck N, Guitart-Masip M, Düzel S. NOvelty-related motivation of anticipation and exploration by dopamine (NOMAD): implications for healthy aging. Neurosci Biobehav Rev 2009; 34:660-9. [PMID: 19715723 DOI: 10.1016/j.neubiorev.2009.08.006] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2009] [Revised: 08/19/2009] [Accepted: 08/20/2009] [Indexed: 12/24/2022]
Abstract
Studies in humans and animals show that dopaminergic neuromodulation originating from the substantia nigra/ventral tegmental area (SN/VTA) of the midbrain enhances hippocampal synaptic plasticity for novel events and has a motivationally energizing effect on actions through striatal mechanisms. In this review, we discuss how these mechanisms of dopaminergic neuromodulation connect to the behavioural and functional consequences that age-related structural degeneration of the SN/VTA exerts on declarative memory. We propose a framework called 'NOvelty-related Motivation of Anticipation and exploration by Dopamine' (NOMAD) which captures existing links between novelty, dopamine, long-term memory, plasticity, energization and their relation to aging. We propose that maximizing the use of this mechanism by maintaining mobility and exploration of novel environments could be a potential mechanism to slow age-related decline of memory.
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Affiliation(s)
- Emrah Düzel
- Institute of Cognitive Neuroscience and Department of Psychology, University College London, 17 Queen Square, London WC1N 3AR, UK.
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Dopamine type-1 receptor binding in major depressive disorder assessed using positron emission tomography and [11C]NNC-112. Neuropsychopharmacology 2009; 34:1277-87. [PMID: 18946469 PMCID: PMC2656589 DOI: 10.1038/npp.2008.194] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The dopamine type-1 receptor has been implicated in major depressive disorder (MDD) by clinical and preclinical evidence from neuroimaging, post mortem, and behavioral studies. To date, however, selective in vivo assessment of D(1) receptors has been limited to the striatum in MDD samples manifesting anger attacks. We employed the PET radioligand, [(11)C]NNC-112, to selectively assess D(1) receptor binding in extrastriatal and striatal regions in a more generalized sample of MDD subjects. The [(11)C]NNC-112 nondisplaceable binding potential (BP(ND)) was assessed using PET in 18 unmedicated, currently depressed subjects with MDD and 19 healthy controls, and compared between groups using MRI-based region-of-interest analysis. The mean D(1) receptor BP(ND) was reduced (14%) in the left middle caudate of the MDD group relative to control group (p<0.05). Among the MDD subjects D(1) receptor BP(ND) in this region correlated negatively with illness duration (r=-0.53; p=0.02), and the left-to-right BP(ND) ratio correlated inversely with anhedonia ratings (r=-0.65, p=0.0040). The D(1) receptor BP(ND) was strongly lateralized in striatal regions (p<0.002 for main effects of hemisphere in accumbens area, putamen, and caudate). In post hoc analyses, a group-by-hemisphere-by-gender interaction was detected in the dorsal putamen, which was accounted for by a loss of the normal asymmetry in depressed women (F=7.33, p=0.01). These data extended a previous finding of decreased striatal D(1) receptor binding in an MDD sample manifesting anger attacks to a sample selected more generally according to MDD criteria. Our data also more specifically localized this abnormality in MDD to the left middle caudate, which is the target of afferent neural projections from the orbitofrontal and anterior cingulate cortices where neuropathological changes have been reported in MDD. Finally, D(1) receptor binding was asymmetrical across hemispheres in healthy humans, compatible with evidence that dopaminergic function in the striatum is lateralized during reward processing, voluntary movement, and self-stimulation behavior.
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Düzel S, Schütze H, Stallforth S, Kaufmann J, Bodammer N, Bunzeck N, Münte TF, Lindenberger U, Heinze HJ, Düzel E. A close relationship between verbal memory and SN/VTA integrity in young and older adults. Neuropsychologia 2008; 46:3042-52. [PMID: 18601938 DOI: 10.1016/j.neuropsychologia.2008.06.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2008] [Revised: 06/02/2008] [Accepted: 06/08/2008] [Indexed: 01/02/2023]
Affiliation(s)
- Sandra Düzel
- Department of Neurology II and Centre for Advanced Imaging, Otto von Guericke Universität, Leipziger Str. 44, 39120 Magdeburg, Germany
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Abstract
AbstractSchizophrenia is being increasingly viewed as a neurodevelopmental disorder, that is, one in which early, fixed pathology becomes manifest clinically during the normal course of maturation of the brain. Evidence for this position comes first from neuroimaging research, such as (1) studies that demonstrate morphologic brain changes (such as ventriculomegaly on CT scans) even in first break patients; and (2) a lack of correlation between these morphologic changes and duration of illness. Another source of evidence is studies of normal brain development in rodents and primates, including research that shows (1) the prefrontal cortex is a late maturing part of the brain, and (2) lesions of the prefrontal cortex may be initially silent and show delayed onset of dysfunction as the brain matures. A neurodevelopmental approach to schizophrenia, in turn, has stimulated further work into the normal development of brain regions implicated in the illness, such as the frontal cortex. Thus, the fields of neuropsychiatry and neurodevelopment have been mutually stimulated during the course of this work. In addition, viewing schizophrenia in developmental terms may have implications for the understanding of changes in cognition and behavior during normal adolescence.
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Bäckman CM, Shan L, Zhang Y, Hoffer BJ, Tomac AC. Alterations in prodynorphin, proenkephalin, and GAD67 mRNA levels in the aged human putamen: correlation with Parkinson's disease. J Neurosci Res 2007; 85:798-804. [PMID: 17203488 DOI: 10.1002/jnr.21164] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A real-time quantitative PCR approach was used to quantify mRNA levels corresponding to the neuropeptides enkephalin, dynorphin, and the 67-kDa isoform of glutamic acid decarboxylase (GAD67) in the human putamen from young and aged individuals as well as from aged patients affected by Parkinson's disease (PD). cDNA-specific primers were designed to amplify GAD67, proenkephalin (pENK), prodynorphin (pDYN), and the housekeeping genes glyceraldehydes-3-phosphate dehydrogenase (GAPDH) and guanine nucleotide binding protein, beta-peptide 2-like I (GNB2LI). GAPDH and GNB2LI mRNA levels were similarly expressed among the groups and were therefore used as endogenous reference genes. Normalized data showed that mRNA levels for both pENK and pDYN were reduced in the putamen of aged controls and aged individuals affected by PD, compared with young controls. In addition, we showed that GAD67 mRNA levels did not change during aging and PD. Further analyses showed no differences in mRNA levels, for pENK, pDYN, or GAD67 mRNA, between PD patients and aged matched controls. These findings contrast with animal models of parkinsonism, for which expression of pDYN, pENK, and GAD67 mRNA has been reported to change after striatal dopamine denervation. Compensatory mechanisms and regional differences within the human putamen as well as the severity index of the disease, clinical diagnosis, and response to phalmacological therapy are possible reasons for these results. The present study suggests that alteration of neuropeptide pathways in the human putamen may be involved in the functional deterioration of parts of the extrapyramidal system during aging.
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Affiliation(s)
- Cristina M Bäckman
- Cellular Neurobiology Branch, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland 21224, USA.
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Scarr E, Sundram S, Keriakous D, Dean B. Altered hippocampal muscarinic M4, but not M1, receptor expression from subjects with schizophrenia. Biol Psychiatry 2007; 61:1161-70. [PMID: 17239354 DOI: 10.1016/j.biopsych.2006.08.050] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2006] [Revised: 05/31/2006] [Accepted: 08/08/2006] [Indexed: 11/26/2022]
Abstract
BACKGROUND Having shown a decrease in [3H]pirenzepine binding in the hippocampus from subjects with schizophrenia, we wished to determine whether such a change in radioligand binding was associated with changes in hippocampal mRNA for the muscarinic1 (M1) and muscarinic4 (M4) receptors in tissue from different cohorts of subjects. METHOD The [3H]pirenzepine binding using autoradiography and in situ hybridization with oligonucleotides specific for muscarinic M1 and M4 receptors were completed using hippocampal tissue obtained postmortem from 20 control subjects and 20 subjects with schizophrenia. RESULTS The [3H]pirenzepine binding was decreased in the dentate gyrus (p < .05), CA3 (p < .01), CA2 (p < .05), and CA1 (p < .01) regions of the hippocampus from subjects with schizophrenia. Levels of M4 mRNA varied with the diagnosis of schizophrenia (p = .01), but significant region-specific changes were not apparent. Changes in levels of mRNA for the muscarinic M1 receptor were not detected with diagnosis. CONCLUSIONS This study suggests that decreases in hippocampal [3H]pirenzepine binding in subjects with schizophrenia are most likely associated with widespread changes in expression levels of the M4 receptor. These data further implicate the hippocampal formation in the pathology of schizophrenia.
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Affiliation(s)
- Elizabeth Scarr
- Rebecca L. Cooper Research Laboratories, Mental Health Research Institute of Victoria, Parkville, VIC, Australia.
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Bunzeck N, Schütze H, Stallforth S, Kaufmann J, Düzel S, Heinze HJ, Düzel E. Mesolimbic novelty processing in older adults. ACTA ACUST UNITED AC 2007; 17:2940-8. [PMID: 17383999 DOI: 10.1093/cercor/bhm020] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Normal aging is associated with neuronal loss in the dopaminergic midbrain (substantia nigra/ventral tegmental area, SN/VTA), a region that has recently been implicated in processing novel stimuli as part of a mesolimbic network including the hippocampus. Here, we quantified age-related structural degeneration of the mesolimbic system using magnetization transfer ratio (MTR) and correlated it with mesolimbic hemodynamic responses (HRs) to stimulus novelty. Twenty-one healthy older adults between 55 and 77 years performed a visual oddball paradigm allowing to distinguish mesolimbic HRs to novelty from rareness, negative emotional valence, and targetness using functional magnetic resonance imaging. The HRs in the right SN/VTA and the right hippocampus to novelty were positively correlated both with the SN/VTA MTR and hippocampus MTR but not amygdala MTR. However, the HR of the amygdala to negative emotional valence correlated with the amygdala MTR but not with the MTR in SN/VTA or the hippocampus. The results establish a structure-function relationship in support of a hippocampal-SN/VTA loop of mesolimbic novelty processing by showing that the hemodynamic activation in SN/VTA and hippocampus for novelty is selectively affected by age-related degeneration of these structures.
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Affiliation(s)
- Nico Bunzeck
- Institute of Cognitive Neuroscience and Department of Psychology, University College London, 17 Queen Square, London, WC1N 3AR, UK
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Funkiewiez A, Ardouin C, Cools R, Krack P, Fraix V, Batir A, Chabardès S, Benabid AL, Robbins TW, Pollak P. Effects of levodopa and subthalamic nucleus stimulation on cognitive and affective functioning in Parkinson's disease. Mov Disord 2007; 21:1656-62. [PMID: 16830317 DOI: 10.1002/mds.21029] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
In Parkinson's disease (PD), levodopa and subthalamic nucleus (STN) stimulation lead to major improvement in motor symptoms. Effects of both treatments on cognition and affective status are less well understood. Motor, cognitive, and affective symptoms may relate to the dysfunctioning of parallel cortico-striatal loops. The aim of this study was to assess cognition, behavior, and mood, with and without both treatments in the same group of PD patients. A group of 22 nondemented PD patients was included in this study. Patients were tested twice before surgery (off and on levodopa) and twice 3 months after surgery (OFF and ON STN stimulation, off levodopa). Cognitive and affective effects of STN stimulation and levodopa had some common, but also different, effects. STN stimulation improved performance on the planning test, associated with the dorsolateral prefrontal cortex. However, the treatments had opposite effects on tests associated with the orbitofrontal cortex; specifically, levodopa impaired while STN stimulation improved performance on the extinction phase of a reversal/extinction task. Acutely, both treatments improved motivation and decreased fatigue and anxiety. On chronic treatment (3 months after surgery), depression improved, whereas apathy worsened 3 months after surgery. To conclude, there were significant but contrasting effects of levodopa and STN stimulation on cognition and affective functions.
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Affiliation(s)
- Aurélie Funkiewiez
- Department of Clinical and Biological Neurosciences, University Hospital of Grenoble, and INSERM U318, Joseph Fourier University of Grenoble, Grenoble, France.
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28
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Hurley MJ, Jenner P. What has been learnt from study of dopamine receptors in Parkinson's disease? Pharmacol Ther 2006; 111:715-28. [PMID: 16458973 DOI: 10.1016/j.pharmthera.2005.12.001] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2005] [Accepted: 12/23/2005] [Indexed: 01/28/2023]
Abstract
Since the introduction of dopamine replacement therapy using L-3,4-dihydroxyphenyalanine (L-DOPA) to treat Parkinson's disease and the recognition of the problems associated with L-DOPA use, numerous studies have investigated dopamine receptor regulation and function in Parkinson's disease. These studies have provided insight into the pathological process of the disorder and the molecular consequences of chronic dopaminergic treatment, but they have been less successful in identifying new pharmacological targets or treatment regimes that are as effective as L-DOPA at alleviating the symptoms of Parkinson's disease. This review will present a summary of the reported changes in dopamine receptor regulation and function that occur in Parkinson's disease and will discuss their contribution to the current pharmacological management of Parkinson's disease.
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Affiliation(s)
- M J Hurley
- Neurodegenerative Diseases Research Group, School of Biomedical and Health Sciences, King's College London, SE1 1UL, United Kingdom.
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Bäckman L, Nyberg L, Lindenberger U, Li SC, Farde L. The correlative triad among aging, dopamine, and cognition: Current status and future prospects. Neurosci Biobehav Rev 2006; 30:791-807. [PMID: 16901542 DOI: 10.1016/j.neubiorev.2006.06.005] [Citation(s) in RCA: 511] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The brain neuronal systems defined by the neurotransmitter dopamine (DA) have since long a recognized role in the regulation of motor functions. More recently, converging evidence from patient studies, animal research, pharmacological intervention, and molecular genetics indicates that DA is critically implicated also in higher-order cognitive functioning. Many cognitive functions and multiple markers of striatal and extrastriatal DA systems decline across adulthood and aging. Research examining the correlative triad among adult age, DA, and cognition has found strong support for the view that age-related DA losses are associated with age-related cognitive deficits. Future research strategies for examining the DA-cognitive aging link include assessing (a) the generality/specificity of the effects; (b) the relationship between neuromodulation and functional brain activation; and (c) the release of DA during actual task performance.
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Affiliation(s)
- Lars Bäckman
- Aging Research Center, Division of Geriatric Epidemiology, Neurotec, Karolinska Institute, Box 6401, S 113 82 Stockholm, Sweden.
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Erixon-Lindroth N, Farde L, Wahlin TBR, Sovago J, Halldin C, Bäckman L. The role of the striatal dopamine transporter in cognitive aging. Psychiatry Res 2005; 138:1-12. [PMID: 15708296 DOI: 10.1016/j.pscychresns.2004.09.005] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2004] [Revised: 08/30/2004] [Accepted: 09/01/2004] [Indexed: 11/17/2022]
Abstract
We examined the relationship of age-related losses of striatal dopamine transporter (DAT) density to age-related deficits in episodic memory and executive functioning in a group of subjects (n = 12) ranging from 34 to 81 years of age. The radioligand [(11)C]beta-CIT-FE was used to determine DAT binding in caudate and putamen. Results showed clear age-related losses of striatal DAT binding from early to late adulthood, and a marked deterioration in episodic memory (word and figure recall, face recognition) and executive functioning (visual working memory, verbal fluency) with advancing age. Most importantly, the age-related cognitive deficits were mediated by reductions in DAT binding, whereas DAT binding added systematic cognitive variance after controlling for age. Further, interindividual differences in DAT binding were related to performance in a test of crystallized intelligence (the Information subtest from the Wechsler Adult Intelligence Scale-Revised) that showed no reliable age variation. These results suggest that DAT binding is a powerful mediator of age-related cognitive changes as well as of cognitive functioning in general. The findings were discussed relative to the view that the frontostriatal network is critically involved in multiple cognitive functions.
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Affiliation(s)
- Nina Erixon-Lindroth
- Department of Psychiatry, Department of Clinical Neuroscience, Karolinska Hospital, Box 6401, S-113 82 Stockholm, Sweden
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Mehta MA, Manes FF, Magnolfi G, Sahakian BJ, Robbins TW. Impaired set-shifting and dissociable effects on tests of spatial working memory following the dopamine D2 receptor antagonist sulpiride in human volunteers. Psychopharmacology (Berl) 2004; 176:331-42. [PMID: 15114435 DOI: 10.1007/s00213-004-1899-2] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2003] [Accepted: 03/29/2004] [Indexed: 10/26/2022]
Abstract
RATIONALE Dopamine (DA) D(2) receptor antagonists have been shown to produce similar impairments to those seen in Parkinson's disease. These include working memory and set-shifting deficits. Theories of DA function have predicted that distraction or impaired switching may be important determinants of such deficits. OBJECTIVES In order to test these hypotheses, we have followed up our previous findings with more refined tests (1) that allow measurement of spatial working memory (SWM) and distraction, (2) that allow separation of executive and mnemonic components of SWM and (3) that allow isolation of set-shifting from learning deficits. METHODS Thirty-six young healthy male volunteers were tested on two occasions after oral administration of either 400 mg sulpiride or placebo. All participants performed the delayed response task. Sixteen participants received task-irrelevant distractors during this task, and were also given a self-ordered SWM test. The remaining participants were given delayed response tasks with task-relevant distractors, and tests of attentional and task set-shifting. RESULTS Sulpiride impaired performance of the delayed-response task both without distraction and with task-relevant distraction. By contrast, the drug protected against deficits from task-irrelevant distraction seen in the placebo group. Task set-switching was also impaired by sulpiride, with participants being slower to respond on switch trials compared with non-switch trials. There was also a trend for attentional set-shifting to be impaired following sulpiride. In contrast, self-ordered SWM performance was enhanced by sulpiride on the second test session only. CONCLUSIONS These results support models of central DA function that postulate a role in switching behaviour, and in certain aspects of working memory.
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Affiliation(s)
- Mitul A Mehta
- Department of Psychiatry, Level E4, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 2QQ, UK.
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Braszko JJ. Involvement of D1 dopamine receptors in the cognitive effects of angiotensin IV and des-Phe6 angiotensin IV. Peptides 2004; 25:1195-203. [PMID: 15245880 DOI: 10.1016/j.peptides.2004.04.014] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2004] [Accepted: 04/27/2004] [Indexed: 10/26/2022]
Abstract
An important role for angiotensin IV (Ang IV) in the processes of learning and memory has now been well established. We have previously found that intracerebroventricular (ICV) administration of Ang IV as well as des-Phe6-Ang IV enhances learning of conditioned avoidance responses (CARs), facilitates recall of a passive avoidance (PA) task, and improves object recognition (OR) in rats. Since the dopaminergic system is crucial for the cognitive processes, in this study our aim was to determine the dopaminergic D1 mediation of these effects using SCH 23390 as a selective D1 receptor antagonist. Male Wistar rats (180-200 g), pretreated with SCH 23390 (R-[+]-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine) 0.05 mg/kg intraperitoneally (IP), were given Ang IV or des-Phe6-Ang IV (1 nmol ICV) 1 h later and then tested in the above cognitive paradigms, as well as in the open field and an elevated 'plus' maze to control for the unspecific, respectively, motor and emotional, effects of our treatments. Both, Ang IV and des-Phe6-Ang IV effectively enhanced learning of CARs (P < 0.05), recall of PA (P < 0.001), and improved OR (P < 0.001). Pretreatment with SCH 23390 abolished the cognitive effects of both peptides. SCH 23390, Ang IV, and des-Phe6-Ang IV, given at the same doses and routes as in the cognitive tests, did not significantly influence crossings, rearings and bar approaches in the open field, nor the parameters measured in the elevated 'plus' maze, thus making a major contribution of the unspecific effects of our treatments to the results of the memory tests improbable. In conclusion, these results indicate that the functional dopaminergic D1 receptors are necessary for the Ang IV and des-Phe6-Ang IV cognitive effects to occur.
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Affiliation(s)
- Jan J Braszko
- Department of Clinical Pharmacology, Medical University of Bialystok, Waszyngtona 15 A, 15274, Poland.
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Hemby SE, Trojanowski JQ, Ginsberg SD. Neuron-specific age-related decreases in dopamine receptor subtype mRNAs. J Comp Neurol 2003; 456:176-83. [PMID: 12509874 PMCID: PMC4048549 DOI: 10.1002/cne.10525] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Age-related decline in dopamine receptor levels has been observed in regional studies of animal and human brains; however, identifying specific cellular substrates and/or alterations in distinct neuronal populations remains elusive. To evaluate whether age-related decreases in dopamine receptor subtypes are associated with specific cell populations in the hippocampus and entorhinal cortex, antisense RNA amplification was combined with cDNA array analysis to examine effects of aging on D1-D5 dopamine receptor mRNA expression levels in hippocampal CA1 pyramidal neurons and entorhinal cortex layer II stellate cells from post-mortem human brains (19-92 years). In CA1 pyramidal neurons, significant age-related decline was observed for dopamine receptor mRNAs (D1-D4, P < 0.001; D5, P < 0.05) but not for the cytoskeletal elements beta-actin, three-repeat (3R) tau, and four-repeat (4R) tau. In contrast, no significant changes were observed in stellate cells across the same cohort. Thus, senescence may be a factor responsible for cell-specific decrements in dopamine receptor gene expression in one population of neurons within a circuit that is critical for learning and memory. Furthermore, these results support the hypothesis that alterations in dopaminergic function may also be related to behavioral abnormalities, such as psychosis, that occur with aging.
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Affiliation(s)
- Scott E Hemby
- Department of Pharmacology and Psychiatry/Behavioral Sciences, Yerkes National Primate Research Center, Neuroscience Division, Emory University School of Medicine, Atlanta, Georgia 30329, USA.
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Abstract
Dopamine (DA) facilitates male sexual behavior and modulates aromatase activity in the quail preoptic area (POA). Aromatase neurons in the POA receive dopaminergic inputs, but the anatomical substrate that mediates the behavioral and endocrine effects of DA is poorly understood. Intracellular recordings showed that 100 microm DA hyperpolarizes most neurons in the medial preoptic nucleus (80%) by a direct effect, but depolarizes a few others (10%). DA-induced hyperpolarizations were not blocked by D1 or D2 antagonists (SCH-23390 and sulpiride). Extracellular recordings confirmed that DA inhibits the firing of most cells (52%) but excites a few others (24%). These effects also were not affected by DA antagonists (SCH-23390 and sulpiride) but were blocked by alpha2-(yohimbine) and alpha1-(prazosin) noradrenergic receptor antagonists, respectively. Two dopamine-beta-hydroxylase (DBH) inhibitors (cysteine and fusaric acid) did not block the DA-induced effects, indicating that DA is not converted into norepinephrine (NE) to produce its effects. The pK(B) of yohimbine for the receptor involved in the DA- and NE-induced inhibitions was similar, indicating that the two monoamines interact with the same receptor. Together, these results demonstrate that the effects of DA in the POA are mediated mostly by the activation of alpha2 (inhibition) and alpha1 (excitation) adrenoreceptors. This may explain why DA affects the expression of male sexual behavior through its action in the POA, which contains high densities of alpha2-noradrenergic but limited amounts of DA receptors. This study thus clearly demonstrates the existence of a cross talk within CNS catecholaminergic systems between a neurotransmitter and heterologous receptors.
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Abstract
BACKGROUND Brain dopamine has been the focus of numerous studies owing to its crucial role in motor function and in neurological and psychiatric disease processes. Whilst early work relied on postmortem data, functional imaging has allowed a more sophisticated approach to the quantification of receptor density, affinity and functional capacity. This review aims to summarise changes in the nigrostriatal dopaminergic system which accompany normal ageing. METHODS A literature search focussed on postmortem and neuroimaging studies of normal ageing within the nigrostriatal dopaminergic tract. The functional significance of age-related effects was also considered. RESULTS There are significant reductions in pre- and post-synaptic markers of brain dopamine activity during normal ageing: However the rate of decline (linear or exponential), the effects of gender and heterogeneity and the mechanisms by which these changes occur remain undetermined. Limited data suggest there is a significant association between postsynaptic receptor density and specific aspects of motor and cognitive function. CONCLUSION The identification of strategies to improve dopaminergic transmission may delay the onset of motor and cognitive deficits associated with normal ageing. In order to develop effective preventative strategies, the causative mechanisms underlying age-related changes and the interaction between synaptic structure and function need to be more clearly elucidated.
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Affiliation(s)
- S Reeves
- Section of Old Age Psychiatry, Institute of Psychiatry, London, UK.
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Amenta F, Mignini F, Ricci A, Sabbatini M, Tomassoni D, Tayebati SK. Age-related changes of dopamine receptors in the rat hippocampus: a light microscope autoradiography study. Mech Ageing Dev 2001; 122:2071-83. [PMID: 11589924 DOI: 10.1016/s0047-6374(01)00317-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Hippocampus is a brain region involved in learning and memory and is particularly sensitive to ageing. It is supplied with a dopaminergic innervation arising from the midbrain, which is part of the mesolimbic dopaminergic pathway. Dysfunction of the dopaminergic mesolimbic system is probably involved in the pathophysiology of psychosis and behavioural disturbances occurring in the elderly. The present study was designed to assess the density and localisation of dopamine D1- and D2-like receptor subtypes in the hippocampus of male Sprague-Dawley rats aged 3 months (young), 12 months (adult) and 24 months (old). Dopamine D1-like receptors, labelled by [3H]-SCH 23390, in young rats displayed a dentate gyrus-CA1 subfield gradient. The expression was increased in the cell body of dentate gyrus, CA4 and CA3 subfield of old rats compared to younger cohorts, as well as in the neuropil of dentate gyrus. A decreased density of dopamine D1-like receptors was found in the stratum oriens of CA1 and CA3 subfields. Dopamine D2-like receptors, labelled using [3H]-spiperone as radioligand, were expressed rather homogeneously throughout different subfields of the hippocampus. In old rats, the density of dopamine D2-like receptors was decreased in the dentate gyrus, unchanged in the CA4 and CA1 subfields and increased in the CA3 subfield. The above results indicate the occurrence of inhomogeneous changes in the density of dopamine D1- and D2-like receptors in specific portions of hippocampus of old rats. These findings support the hypothesis of an involvement of dopaminergic system in behavioural abnormalities or psychosis occurring in ageing.
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Affiliation(s)
- F Amenta
- Sezione di Anatomia Umana, Dipartimento di Scienze Farmacologiche e Medicina Sperimentale, Università di Camerino, Via Scalzino, 3, 62032, Camerino, Italy.
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Sawaguchi T. The effects of dopamine and its antagonists on directional delay-period activity of prefrontal neurons in monkeys during an oculomotor delayed-response task. Neurosci Res 2001; 41:115-28. [PMID: 11591439 DOI: 10.1016/s0168-0102(01)00270-x] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To examine the role of dopamine receptors in the memory field of neurons for visuospatial working memory in the prefrontal cortex (PFC), dopamine and its antagonists (SCH23390 for the D1-antagonist and sulpiride for the D2-antagonist) were applied iontophoretically to neurons of the dorsolateral PFC in monkeys that performed an oculomotor delayed-response task. In this task, the subject made a memory-guided saccade to a remembered target location that had been cued by a visuospatial stimulus (right, up, left, or down; 15 degrees in eccentricity) prior to a 4-s delay period. We focused here on PFC neurons that showed directional delay-period activity; i.e., an increased activity during the delay period, the magnitude of which varied significantly with the target location. Iontophoretic application of SCH23390 (usually 50 nA) decreased or increased the activities of most of these neurons (n=48/62, 77%); most neurons showed a decrease (n=43/62, 69%). For the neurons affected by SCH23390, a directional index of directional delay-period activity was attenuated by SCH23390, whereas the preferred direction was not greatly affected. The decreasing effect of SCH23390 was dose-dependent; the extent of the decrease was less with a lower dose (20-nA current) than with the ordinary dose (50-nA current), although the effect of the lower dose of SCH23390 on delay-period activity was similar in nature to that of the ordinary dose of SCH23390. Furthermore, the application of dopamine itself augmented directional delay-period activity in most of the neurons tested (n=12/16, 75%). Sulpiride did not have any significant effects in most of the neurons tested (n=15/17). These results suggest that the activation of D1-dopamine receptors play a facilitating role in the memory field of PFC neurons for visuospatial working memory processes.
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MESH Headings
- Action Potentials/drug effects
- Action Potentials/physiology
- Animals
- Benzazepines/pharmacology
- Databases, Factual
- Dopamine/metabolism
- Dopamine/pharmacology
- Dopamine Antagonists/pharmacology
- Dopamine D2 Receptor Antagonists
- Dose-Response Relationship, Drug
- Eye Movements/drug effects
- Eye Movements/physiology
- Iontophoresis
- Macaca mulatta
- Male
- Memory, Short-Term/drug effects
- Memory, Short-Term/physiology
- Neurons/cytology
- Neurons/metabolism
- Prefrontal Cortex/cytology
- Prefrontal Cortex/metabolism
- Psychomotor Performance/drug effects
- Psychomotor Performance/physiology
- Reaction Time/drug effects
- Reaction Time/physiology
- Receptors, Dopamine/drug effects
- Receptors, Dopamine/metabolism
- Receptors, Dopamine D1/agonists
- Receptors, Dopamine D1/antagonists & inhibitors
- Receptors, Dopamine D1/metabolism
- Receptors, Dopamine D2/agonists
- Receptors, Dopamine D2/metabolism
- Saccades/drug effects
- Saccades/physiology
- Sulpiride/pharmacology
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Affiliation(s)
- T Sawaguchi
- Laboratory of Neurobiology, Graduate School of Medicine, Hokkaido University, N15 W7, Kita-ku, Sapporo 060-8638, Japan.
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38
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Dean B, Hussain T. Studies on dopaminergic and GABAergic markers in striatum reveals a decrease in the dopamine transporter in schizophrenia. Schizophr Res 2001; 52:107-14. [PMID: 11595397 DOI: 10.1016/s0920-9964(00)00096-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Changes in the interaction between dopaminergic and GABAergic systems in the striatum have been suggested to be important in the pathology of schizophrenia. If that hypothesis is correct, these changes could produce inter-related changes in the dopaminergic and GABAergic systems in the striatum from schizophrenic subjects. To test this proposition we measured important markers on dopaminergic and GABAergic neurons in striatum obtained post-mortem from schizophrenic and non-schizophrenic subjects. There was a significant decrease in the density of the dopamine transporter (mean+/-SEM: 230+/-31 vs. 334+/-22fmol/mg ETE; P=0.01), but not nitric oxide synthase, dopamine D(2)-like, D(1)-like, D(3) or GABA(A) receptors in subjects with schizophrenia. There were no inter-related changes in the dopaminergic or GABAergic markers. In the schizophrenic subjects, the density of dopamine D(1)-like receptors decreased with age and was positively correlated with the density of dopamine D(2)-like receptors. This study does not readily add weight to the hypothesis that changes in the interaction between dopamine and GABA in the striatum are important in the pathology of schizophrenia. However, our findings could indicate that changes in the dopamine transporter within the striatum, either because of decreased transporter numbers per se or as a result of innervating neuronal loss, may be involved in the pathology of the illness.
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Affiliation(s)
- B Dean
- The Rebecca Cooper Research Laboratories, The Division of Molecular Schizophrenia, The Mental Health Research Institute, Victoria, 3052, Parkville, Australia.
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39
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Hurd YL, Suzuki M, Sedvall GC. D1 and D2 dopamine receptor mRNA expression in whole hemisphere sections of the human brain. J Chem Neuroanat 2001; 22:127-37. [PMID: 11470560 DOI: 10.1016/s0891-0618(01)00122-3] [Citation(s) in RCA: 187] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Understanding dopamine signaling in human behavior requires knowledge of the distribution of all molecular components involved in dopamine pathways throughout the human brain. In the present study, the relative distributions of D1 and D2 dopamine receptor mRNAs were determined by in situ hybridization histochemistry in whole hemisphere sections from normal human post mortem brains. The findings confirmed information documented from single structure examination that the highest expression of both the D1 and D2 mRNAs were localized to the striatum. The cerebral cortex expressed moderate D1 mRNA in all regions with the highest signal in the medial orbital frontal area (Brodmann areas 11, 14), the paraterminal gyrus (Brodmann area 32) and the insular cortex (Brodmann areas 13-16), whereas the D2 mRNA expression had very low cortical expression. The bed nucleus of the stria terminalis and islands of Calleja had high expression of the D1 mRNA and moderate D2 mRNA levels. Moderate to high expression of the D2 mRNA was evident in the hippocampal formation, parafascicular and paraventricular thalamic nuclei, geniculate bodies, subthalamic nucleus, and pineal gland, all of which were devoid of, or showed only faint, D1 mRNA expression. Brainstem regions, e.g. substantia nigra, red nucleus, inferior colliculus, medial lemniscus, and pontine nuclei expressed D2, but not D1, mRNA. These results emphasize the differential anatomical localization of D1 and D2 dopamine receptor mRNA neuronal populations in the human brain. The restricted expression of the D1 mRNA to the cortical mantle and to a few forebrain structures indicates a strong involvement of the D1 system in cognitive function.
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Affiliation(s)
- Y L Hurd
- Psychiatry Section, Department of Clinical Neuroscience, Karolinska Institutet, Karolinska Hospital, SE-171 76, Stockholm, Sweden.
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40
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Abstract
The prefrontal cortex (PFC) has long been known to be involved in the mediation of complex behavioral responses. Considerable research efforts are directed towards refining the knowledge about the function of this brain area and the role it plays in cognitive performance and behavioral output. In the first part, this review provides, from a pharmacological perspective, an overview of anatomical, electrophysiological and neurochemical aspects of the function of the PFC, with an emphasis on the mesocortical dopamine system. Anatomy of the mesocortical system, basic physiological and pharmacological properties of neurotransmission within the PFC, and interactions between dopamine and glutamate as well as other transmitters within the mesocorticolimbic circuit are included. The coverage of these data is largely restricted to what is relevant for the second part of the review which focuses on behavioral studies that have examined the role of the PFC in a variety of phenomena, behaviors and paradigms. These include reward and addiction, locomotor activity and sensitization, learning, cognition, and schizophrenia. Although the focus of this review is on the mesocortical dopamine system, given the intricate interactions of dopamine with other transmitter systems within the PFC and the importance of the PFC as a source of glutamate in subcortical areas, these aspects are also covered in some detail where appropriate. Naturally, a topic as complex as this cannot be covered comprehensively in its entirety. Therefore this review is largely limited to data derived from studies using rats, and it is also specifically restricted to data concerning the medial PFC (mPFC). Since in several fields of research the findings concerning the function or role of the mPFC are relatively inconsistent, the question is addressed whether these inconsistencies might, at least in part, be related to the anatomical and functional heterogeneity of this brain area.
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Affiliation(s)
- T M Tzschentke
- Grünenthal GmbH, Research and Development, Department of Pharmacology, Postfach 500444, 52088, Aachen, Germany.
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41
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Fedele E, Mazzone P, Stefani A, Bassi A, Ansaldo MA, Raiteri M, Altibrandi MG, Pierantozzi M, Giacomini P, Bernardi G, Stanzione P. Microdialysis in Parkinsonian patient basal ganglia: acute apomorphine-induced clinical and electrophysiological effects not paralleled by changes in the release of neuroactive amino acids. Exp Neurol 2001; 167:356-65. [PMID: 11161624 DOI: 10.1006/exnr.2000.7568] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
During stereotaxic neurosurgery for deep brain stimulation in Parkinson's disease (PD), we performed a microdialysis study of the extracellular amino acid (aspartate, glutamate, glycine, and GABA) concentrations. Their levels were measured in the GPe/GPi of five and in the STN of four different PD patients, after prolonged therapy washout. The results show stable values of basal release of the examined amino acids within 1 h. The basal levels of GABA in "OFF" state were significantly higher in the GPi than in the GPe. Acute apomorphine administration, while inducing clinical amelioration and electrophysiological changes in the examined nuclei, did not change amino acid concentrations. This result could be related to a limited microdialysis ability to detect subtle changes in amino acid spontaneous release. Alternatively, it could suggest that dopaminergic receptors located in the output nuclei, possibly present also in humans, might mediate the acute apomorphine clinical effects, not involving amino acid changes along the direct and/or indirect pathway.
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Affiliation(s)
- E Fedele
- Dipartimento di Medicina Sperimentale, Sezione di Farmacologia e Tossicologia, Viale Cembrano 4, 16148 Genova, Italy
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The role of D1-dopamine receptors in working memory-guided movements mediated by frontal cortical areas. Parkinsonism Relat Disord 2000; 7:9-19. [PMID: 11008191 DOI: 10.1016/s1353-8020(00)00044-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Like the striatum, the frontal motor cortices receive dopaminergic fibers from midbrain dopamine cells and contain high levels of dopamine receptors. Among frontal cortical areas, the dorsolateral PFC (PFd1) and the dorsal premotor cortex (PMd) have strong neural connections and play a major role for working memory-guided directional movements. To reveal the role of dopamine in this cognitive motor function, dopamine antagonists (SCH23390 for D1 receptors and sulpiride for D2 receptors) were applied locally or iontophoretically to the PFd1 and PMd in monkeys that performed delayed-response tasks with memory-guided directional movements. Applications of SCH23390, but not sulpiride, to these areas had significant effects at both the behavioral and neuronal levels. In the PFd1 and at the behavioral level, local injections of SCH23390 induced specific errors for memory-guided saccades, whereas it had no effects on visually guided saccades. In the PMd, local injections of SCH23390 induced directional errors and increased reaction time and movement time in memory-guided reaching movements. At the neuron level, iontophoretic applications of SCH23390 attenuated directional tuning of neurons of the PFd1 and PMd, which showed directional activities during the delay-and/or response-period(s). These findings suggest that the activation of D1-dopamine receptors in these frontal cortical areas plays a facilitating role in a series of neuronal processes of working memory-guided directional movements; the working memory process for guiding motor act in the PFd1 and preparation/control of directional manual movements in the PMd. In addition, our findings may provide insight into symptoms of schizophrenia and Parkinson's disease; the dysfunction of D1-dopamine receptors in the PMd1 and PMd may contribute to some symptoms, such as bradyphrenia and bradykinesia, in these disorders.
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43
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Glass M, Dragunow M, Faull RL. The pattern of neurodegeneration in Huntington's disease: a comparative study of cannabinoid, dopamine, adenosine and GABA(A) receptor alterations in the human basal ganglia in Huntington's disease. Neuroscience 2000; 97:505-19. [PMID: 10828533 DOI: 10.1016/s0306-4522(00)00008-7] [Citation(s) in RCA: 393] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In order to investigate the sequence and pattern of neurodegeneration in Huntington's disease, the distribution and density of cannabinoid CB(1), dopamine D(1) and D(2), adenosine A(2a) and GABA(A) receptor changes were studied in the basal ganglia in early (grade 0), intermediate (grades 1, 2) and advanced (grade 3) neuropathological grades of Huntington's disease. The results showed a sequential pattern of receptor changes in the basal ganglia with increasing neuropathological grades of Huntington's disease. First, the very early stages of the disease (grade 0) were characterized by a major loss of cannabinoid CB(1), dopamine D(2) and adenosine A(2a) receptor binding in the caudate nucleus, putamen and globus pallidus externus and an increase in GABA(A) receptor binding in the globus pallidus externus. Second, intermediate neuropathological grades (grades 1, 2) showed a further marked decrease of CB(1) receptor binding in the caudate nucleus and putamen; this was associated with a loss of D(1) receptors in the caudate nucleus and putamen and a loss of both CB(1) and D(1) receptors in the substantia nigra. Finally, advanced grades of Huntington's disease showed an almost total loss of CB(1) receptors and the further depletion of D(1) receptors in the caudate nucleus, putamen and globus pallidus internus, and an increase in GABA(A) receptor binding in the globus pallidus internus. These findings suggest that there is a sequential but overlapping pattern of neurodegeneration of GABAergic striatal efferent projection neurons in increasing neuropathological grades of Huntington's disease. First, GABA/enkephalin striatopallidal neurons projecting to the globus pallidus externus are affected in the very early grades of the disease. Second, GABA/substance P striatonigral neurons projecting to the substantia nigra are involved at intermediate neuropathological grades. Finally, GABA/substance P striatopallidal neurons projecting to the globus pallidus internus are affected in the late grades of the disease. In addition, the finding that cannabinoid receptors are dramatically reduced in all regions of the basal ganglia in advance of other receptor changes in Huntington's disease suggests a possible role for cannabinoids in the progression of neurodegeneration in Huntington's disease.
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Affiliation(s)
- M Glass
- Departments of Anatomy with Radiology, University of Auckland, Private Bag 92019, Auckland, New Zealand
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44
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Smeets WJ, González A. Catecholamine systems in the brain of vertebrates: new perspectives through a comparative approach. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 2000; 33:308-79. [PMID: 11011071 DOI: 10.1016/s0165-0173(00)00034-5] [Citation(s) in RCA: 300] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A comparative analysis of catecholaminergic systems in the brain and spinal cord of vertebrates forces to reconsider several aspects of the organization of catecholamine systems. Evidence has been provided for the existence of extensive, putatively catecholaminergic cell groups in the spinal cord, the pretectum, the habenular region, and cortical and subcortical telencephalic areas. Moreover, putatively dopamine- and noradrenaline-accumulating cells have been demonstrated in the hypothalamic periventricular organ of almost every non-mammalian vertebrate studied. In contrast with the classical idea that the evolution of catecholamine systems is marked by an increase in complexity going from anamniotes to amniotes, it is now evident that the brains of anamniotes contain catecholaminergic cell groups, of which the counterparts in amniotes have lost the capacity to produce catecholamines. Moreover, a segmental approach in studying the organization of catecholaminergic systems is advocated. Such an approach has recently led to the conclusion that the chemoarchitecture and connections of the basal ganglia of anamniote and amniote tetrapods are largely comparable. This review has also brought together data about the distribution of receptors and catecholaminergic fibers as well as data about developmental aspects. From these data it has become clear that there is a good match between catecholaminergic fibers and receptors, but, at many places, volume transmission seems to play an important role. Finally, although the available data are still limited, striking differences are observed in the spatiotemporal sequence of appearance of catecholaminergic cell groups, in particular those in the retina and olfactory bulb.
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Affiliation(s)
- W J Smeets
- Graduate School of Neurosciences of Amsterdam, Research Institute of Neurosciences, Amsterdam, The Netherlands.
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Otsuka H, Nakase H, Nagata K, Ueda K, Kempski O, Sakaki T. Effect of age on cerebral venous circulation disturbances in the rat. J Neurosurg 2000; 93:298-304. [PMID: 10930017 DOI: 10.3171/jns.2000.93.2.0298] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Mild cerebral venous circulation disturbances (CVCDs) in aged patients are frequently known to cause unexpectedly severe postoperative complications in neurosurgical practice. The object of the present study was to determine whether there are age-related differences involved in vulnerability to CVCDs. METHODS Thirty-eight male Wistar rats were used. A single cortical vein with a 100-microm diameter was occluded photochemically by using rose bengal dye and fiberoptic illumination in young (Group Y, 19 animals aged 10-14 weeks) and aged (Group A, seven animals aged 80-100 weeks) rats. Five young and seven aged animals served as sham-operated controls. Regional cerebral blood flow (rCBF) was determined from local CBF, which was measured at 25 (5 x 5) identical locations, with the occluded vein located central to the scanning field, by using a laser Doppler scanning technique every 15 minutes for 90 minutes after venous occlusion. The cerebral venous flow pattern was examined using fluorescence angiography until 90 minutes after occlusion. Histological specimens were examined 24 hours after occlusion. In Group Y, rCBF did not change significantly after venous occlusion. However, in Group A, rCBF decreased rapidly beginning 15 minutes after occlusion. Significant intergroup differences were observed 30, 60, and 90 minutes after occlusion. Venous flow arrest, which resulted in venous infarct, was observed on angiography 90 minutes after occlusion in two (10.5%) of 19 young and six (85.7%) of seven aged rats. The venous thrombus in Group A rats was significantly larger than that in Group Y rats 90 minutes after occlusion. Venous infarction was seen in all aged rats (100%) and in six young rats (31.6%); the infarct size, expressed as a percentage of the size of the ipsilateral hemisphere, was significantly larger in aged rats than in young rats. CONCLUSIONS This study demonstrated an age-related increase in the rate and size of venous infarct following vein occlusion, suggesting that the greater vulnerability to CVCDs in the aged brain might be attributed to early and extensive hypoperfusion of circumscribed brain areas drained by the occluded vein. The larger thrombus formation in aged animals indicates that a shift in the thrombogenetic/thrombolytic equilibrium is responsible for the observed effect.
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Affiliation(s)
- H Otsuka
- Department of Neurosurgery, Nara Medical University, Kashihara City, Japan
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Mijnster MJ, Isovich E, Flügge G, Fuchs E. Localization of dopamine receptors in the tree shrew brain using [3H]-SCH23390 and [125I]-epidepride. Brain Res 1999; 841:101-13. [PMID: 10546993 DOI: 10.1016/s0006-8993(99)01795-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The tree shrew is a mammalian species, which is phylogenetically related to insectivores and primates. The aim of the present study was to investigate the distribution of dopamine receptor D1- and D2-like binding sites in the brain of this non-rodent, non-primate mammal. Using in vitro autoradiography and employing the radioligands [3H]-SCH23390 and [125I]-epidepride, dopamine receptors were mapped and quantified. Significant findings with regard to the D1-like binding pattern include the presence of a "patchy" binding in the striatum. In the cortex, D1-like binding sites were observed in both the superficial and the deep layers. In the hippocampal formation, D1-like binding sites were seen primarily in the CAI region and not in the dentate gyrus. These characteristics of the D1 pattern in the tree shrew brain are shared by cat and monkey and human brain, but not by rodent brain. Significant findings with regard to the D2-like binding pattern include the presence of D2-like binding in the claustrum. In addition, the striatum demonstrated "patchy" D2-like binding. These characteristics of the D2 pattern in the tree shrew brain are shared by cat and monkey and human brain, but not by rodent brain. On the other hand, the significant densities of D2-like binding sites in the glomerular layer of the tree shrew olfactory bulb is a finding that discriminates tree shrews from higher evolutionary species who lack such binding. Overall, the evidence coincides with the view that tree shrews are phylogenetically related to primates.
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Piggott MA, Marshall EF, Thomas N, Lloyd S, Court JA, Jaros E, Burn D, Johnson M, Perry RH, McKeith IG, Ballard C, Perry EK. Striatal dopaminergic markers in dementia with Lewy bodies, Alzheimer's and Parkinson's diseases: rostrocaudal distribution. Brain 1999; 122 ( Pt 8):1449-68. [PMID: 10430831 DOI: 10.1093/brain/122.8.1449] [Citation(s) in RCA: 212] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Dementia with Lewy bodies (DLB) is a neuropsychiatric disease associated with extrapyramidal features which differ from those of Parkinson's disease, including reduced effectiveness of L-dopa and severe sensitivity reactions to neuroleptic drugs. Distinguishing Alzheimer's disease from DLB is clinically relevant in terms of prognosis and appropriate treatment. Dopaminergic activities have been investigated at coronal levels along the rostrocaudal striatal axis from a post-mortem series of 25 DLB, 14 Parkinson's disease and 17 Alzheimer's disease patients and 20 elderly controls. [(3)H]Mazindol binding to the dopamine uptake site was significantly reduced in the caudal putamen in DLB compared with controls (57%), but not as extensively as in Parkinson's disease (75%), and was unchanged in Alzheimer's disease. Among three dopamine receptors measured (D1, D2 and D3), the most striking changes were apparent in relation to D2. In DLB, [(3)H]raclopride binding to D2 receptors was significantly reduced in the caudal putamen (17%) compared with controls, and was significantly lower than in Parkinson's disease at all levels. D2 binding was significantly elevated at all coronal levels in Parkinson's disease compared with controls, most extensively in the rostral putamen (71%). There was no change from the normal pattern of D2 binding in Alzheimer's disease. The only significant alteration in D1 binding ([(3)H]SCH23390) in the groups examined was an elevation (30%) in the caudal striatum in Parkinson's disease. There were no differences in D3 binding, measured using [(3)H]7-OH-DPAT, in DLB compared with controls. A slight, significant decrease in D3 binding in the caudal striatum of Parkinson's disease (13%) patients and an increase in Alzheimer's disease (20%) in the dorsal striatum at the level of the nucleus accumbens were found. The concentration and distribution of dopamine were disrupted in both DLB and Parkinson's disease, although in the caudate nucleus the loss of dopamine in DLB was uniform whereas in Parkinson's disease the loss was greater caudally. In the caudal putamen, dopamine was reduced by 72% in DLB and by 90% in Parkinson's disease. The homovanillic acid : dopamine ratio, a metabolic index, indicated compensatory increased turnover in Parkinson's disease, which was absent in DLB despite the loss of substantia nigra neurons (49%), dopamine and uptake sites. These differences between DLB, Parkinson's disease and Alzheimer's disease may explain some characteristics of the extrapyramidal features of DLB and its limited response to L-dopa and severe neuroleptic sensitivity. The distinct changes in the rostrocaudal pattern of expression of dopaminergic parameters are relevant to the interpretation of the in vivo imaging and diagnosis of DLB.
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Affiliation(s)
- M A Piggott
- MRC Neurochemical Pathology Unit, Department of Neuropathology, Old Age Psychiatry, Newcastle General Hospital, Newcastle-upon-Tyne, NE4 6BE, UK.
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Abstract
In contrast to the well-established dopaminergic innervation of the neostriatum, the existence of dopaminergic innervation of the subthalamic nucleus and globus pallidus is controversial. In the present study, tyrosine hydroxylase (TH)-immunoreactive elements were observed by light microscopy after antigen retrieval in the subthalamic nucleus and in the internal and external segments of the globus pallidus in postmortem human brain. Small islands of apparent neostriatal tissue with abundant arborization of fine, TH-immunoreactive axons in the vicinity of calbindin-positive small neurons resembling neostriatal medium spiny neurons were present in the external segment of the globus pallidus. Large numbers of medium-large, TH-immunoreactive axons were observed passing above and through the subthalamic nucleus and through both pallidal segments; these are presumed to be axons of passage on their way to the neostriatum. In addition, fine, TH-immunoreactive axons with meandering courses, occasional branches, and irregular outlines, morphologically suggestive of terminal axon arborizations with varicosities, were seen in both pallidal segments, including the ventral pallidum, and the subthalamic nucleus, consistent with a catecholaminergic (probably dopaminergic) innervation of these nuclei. This finding suggests that, in Parkinson's disease and in animal models of this disorder, loss of dopaminergic innervation might contribute to abnormal neuronal activation in these three nuclei.
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Affiliation(s)
- J C Hedreen
- Department of Psychiatry, New England Medical Center and the Tufts University School of Medicine, Boston, Massachusetts 02111, USA.
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Piggott MA, Marshall EF, Thomas N, Lloyd S, Court JA, Jaros E, Costa D, Perry RH, Perry EK. Dopaminergic activities in the human striatum: rostrocaudal gradients of uptake sites and of D1 and D2 but not of D3 receptor binding or dopamine. Neuroscience 1999; 90:433-45. [PMID: 10215149 DOI: 10.1016/s0306-4522(98)00465-5] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The human striatum, which receives dopaminergic innervation from the substantia nigra and ventral tegmental area (cell groups A8, A9 and A10), has structural and functional subdivisions both rostrocaudally and dorsoventrally. These relate to motor and non-motor origins of cortical projections and the specific areas of the substantia nigra and ventral tegmental area providing dopaminergic innervation. In the present study, we have evaluated the distribution of a number of dopaminergic parameters in the caudate, putamen and nucleus accumbens at separate coronal levels in a post mortem study in a series of elderly normal individuals aged 55-94 years, with analysis of the effect of post mortem variables. Dopamine D1 receptor density displayed a rostrocaudally declining gradient in the putamen but not in the caudate, such that at levels posterior to the anterior commissure, there was significantly lower D1 binding in the putamen compared to the caudate. The density of dopamine D2 receptors was similar in the putamen and caudate, increasing rostrocaudally. The density of dopamine uptake sites exhibited an increasing rostrocaudal gradient in the caudate, especially ventrally, but not in the putamen, where binding was more constant. The dopamine D3 receptor was concentrated in the ventral striatum, particularly the nucleus accumbens, although there was no evidence of a rostrocaudal gradient. With respect to striosome-matrix compartmentalization, there was no complete segregation, although D1 and D3 receptors were concentrated in striosomes, whereas D2 receptors and uptake sites showed higher density in the matrix. Levels of dopamine were similar in the caudate and putamen, and were significantly elevated at levels including the nucleus accumbens and the anterior commissure. Homovanillic acid and the metabolic index (homovanillic acid/dopamine ratio) were significantly higher in the putamen compared to the caudate, especially at levels from and caudal to the anterior commissure. These distributions of dopamine receptors and metabolic indicators, reflecting the different functional domains of the striatum, are relevant to the interpretation of current in vivo imaging of the dopamine transporter and receptors in neurological and psychiatric disorders. They provide information to assist in the detection of perturbations in expression, in specific diseases, at particular points on rostrocaudal, lateromedial and dorsoventral axes, a level of resolution beyond current neuroimaging capability.
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Affiliation(s)
- M A Piggott
- MRC Neurochemical Pathology Unit, Newcastle General Hospital, Newcastle-upon-Tyne, UK
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Abstract
There is recognition that the cognitive symptoms of schizophrenia have the most substantial impact on illness outcome. Domains of cognition reported to be significantly affected include serial learning, executive function, vigilance, and distractibility, to name a few. Dopamine activity at D1 receptors mediates many cognitive processes subserved by the prefrontal cortex (PFC), particularly working memory. The number of D1 receptors in the PFC is decreased in schizophrenics and is unaffected by chronic administration of typical neuroleptics. Therefore, medications that increase dopamine in the PFC, such as atypical neuroleptics, or that directly activate the D1 receptor may prove useful in the remediation of prefrontal-dependent cognitive deficits in schizophrenia. Decreased levels of cortical norepinephrine (NE) are associated with impaired learning and working memory in animal models, and can be reversed by drugs that restore NE activity. More specifically, alpha-2 adrenergic receptor agonists have been particularly effective in improving delayed response performance in young monkeys with localized 6-hydroxydopamine lesions in the PFC. Furthermore, human postmortem studies have demonstrated decreased NE in the frontal cortex of demented schizophrenic patients. Therefore, alpha-2 receptor agonists hold promise as drugs to improve cognitive performance on tasks dependent upon PFC function in schizophrenics. Finally, the finding that cortical choline acetyl transferase activity correlates with Clinical Dementia Rating scores in schizophrenic patients and that cholinomimetic drugs enhance cognition in healthy subjects suggests that cholinergic drugs may also treat cognitive symptoms in schizophrenia. Two potential types of cholinomimetics for use in schizophrenics are the acetylcholinesterase inhibitors and M1/M4 muscarinic agonists, both of which increase cortical cholinergic activity.
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Affiliation(s)
- J I Friedman
- Department of Psychiatry, Mount Sinai School of Medicine, New York, New York 10029, USA
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