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Li H, Lin LY, Zhang Y, Lim Y, Rahman M, Beck A, Al-Hawwas M, Feng S, Bobrovskaya L, Zhou XF. Pro-BDNF Knockout Causes Abnormal Motor Behaviours and Early Death in Mice. Neuroscience 2020; 438:145-157. [PMID: 32413397 DOI: 10.1016/j.neuroscience.2020.05.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 05/05/2020] [Accepted: 05/06/2020] [Indexed: 12/27/2022]
Abstract
Brain derived neurotrophic factor (BDNF) is a member of the neurotrophin family, best characterized for its survival and differentiative effects in the central nervous system. Pro-BDNF, known as the precursor of BDNF, is believed to have opposite functions to mature BDNF (mBDNF). The opposing effects of Pro-BDNF and mBDNF have led researchers to propose a 'yin' (Pro-BDNF) and 'yang' (mBDNF) model of which, the specific mechanism of its opposing functions is unclear and requires further investigation. In order to elucidate pro-BDNF's explicit role, we established a pro-BDNF knockout (KO) mouse model. This BDNF pro-domain KO mouse model showed significant weight loss, impaired righting reflex, abnormal motor behaviours and short lifespan (less than 22 days), mimicking a Huntington's disease (HD)-like phenotype. ELISA results showed BDNF pro-domain KO not only blocked pro-BDNF, but also significantly affected the level of mBDNF. Abnormal morphologic changes were found in the dentate gyrus (DG) of the hippocampus in pro-BDNF KO mice, and western blot confirmed significant cell apoptosis in pro-BDNF KO mice brains. Furthermore, the expression of glutamic acid decarboxylase 65/67 (GAD65/67) was significantly reduced in pro-BDNF KO mice, indicating impaired inhibitory neurotransmission. Heterozygous (Het) mice showed impaired learning and memory capability and depressive-like behaviours, compared with wild type (WT) mice. Overall, these results support that pro-domain of BDNF is an indispensable part of the BDNF gene; without the proper formation of pro-BDNF, mBDNF cannot be produced successfully and function correctly on its own. Our study also supports the BDNF hypothesis in the pathogenesis of HD.
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Affiliation(s)
- Hua Li
- School of Pharmacy and Medical Sciences, Division of Health Sciences, University of South Australia, Adelaide, SA 5001, Australia
| | - Li-Ying Lin
- School of Pharmacy and Medical Sciences, Division of Health Sciences, University of South Australia, Adelaide, SA 5001, Australia
| | - Yan Zhang
- School of Pharmacy and Medical Sciences, Division of Health Sciences, University of South Australia, Adelaide, SA 5001, Australia; Department of Orthopaedics, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Yoon Lim
- Centre for Cancer Biology, University of South Australia, Adelaide, SA 5001, Australia
| | - Mehreen Rahman
- School of Pharmacy and Medical Sciences, Division of Health Sciences, University of South Australia, Adelaide, SA 5001, Australia
| | - Andrew Beck
- School of Pharmacy and Medical Sciences, Division of Health Sciences, University of South Australia, Adelaide, SA 5001, Australia
| | - Mohammed Al-Hawwas
- School of Pharmacy and Medical Sciences, Division of Health Sciences, University of South Australia, Adelaide, SA 5001, Australia
| | - Shiqing Feng
- Department of Orthopaedics, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Larisa Bobrovskaya
- School of Pharmacy and Medical Sciences, Division of Health Sciences, University of South Australia, Adelaide, SA 5001, Australia
| | - Xin-Fu Zhou
- School of Pharmacy and Medical Sciences, Division of Health Sciences, University of South Australia, Adelaide, SA 5001, Australia.
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Manalo RVM. Cytosolic non-vesicular dopamine accumulation as the predominant mechanism for developing non-DOPA responsive parkinsonism in late-stage Huntington disease. Med Hypotheses 2019; 132:109377. [PMID: 31466019 DOI: 10.1016/j.mehy.2019.109377] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 08/09/2019] [Accepted: 08/20/2019] [Indexed: 12/30/2022]
Abstract
Disturbances in motor movement can have similar clinical presentations, albeit having different pathways and temporal onset. Hypokinetic movements present with rigidity, resting tremors, postural instability and bradykinesia, as seen in parkinsonism, while hyperkinetic movements typically present with chorea, ballismus, tic, athetosis and dystonia. Nonetheless, movement disorders are thought to be a continuum. Long-term therapy of parkinsonism with L-DOPA or dopamine (DA) agonists leads to late-onset dyskinesia - a hyperkinetic movement disorder, while patients with late-stage Huntington disease (HD) often develop non-DOPA responsive parkinsonism. In this paper, it is proposed that late-onset parkinsonism is driven by the overactivity of the nigrostriatal dopaminergic pathway. The excessive synthesis, storage, release, reuptake and degradation of dopamine in the presynaptic terminal and synaptic clefts lead to cellular stress and damage, resulting to progressive neuroapoptosis aggravated by pro-parkinsonism drugs used to treat hyperkinesia. Glutamate excitotoxicity may provide initial stress to neurons during early HD - but as the disease advances, lower glutamate levels are observed, making it less likely to cause the hypokinetic shift on its own. Over time, dopaminergic neurons are depleted and cholinergic influence to striatal GABA release is unopposed, leading to late-onset parkinsonism that is unresponsive to DOPA challenge, due to drastic DA neuron loss previously masked by the dominating choreic presentation. This paper thus provides a mechanism of action to a common clinical sequela and complication of long-term choreic diseases, whose pathophysiologic mechanism is presently lacking.
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Affiliation(s)
- Rafael Vincent M Manalo
- College of Medicine, University of the Philippines Manila, Ermita, Manila 1000, Philippines.
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3
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Abstract
Premortem, postmortem, and storage conditions are parameters that can influence the quality and interpretation of data from studies of postmortem tissue. While many neurochemicals in the brain are relatively stable for several hours after death if stored at 4°C, the postmortem delay nevertheless becomes an important variable when examining the disease state because neurochemical levels may change with extended postmortem delay. Moreover, in the postmortem brain, neurochemical levels may also play a key role in determining the diagnosis. This is particularly true for some neurodegenerative disorders where many of the clinical features of the disease are not exclusive to one illness. It is therefore imperative to employ brain tissue of the highest quality from both nondiseased (control) and diseased brain tissue to ascertain the specific molecular and genetic mechanisms particular to the disease pathogenesis. Consequently, it would be very useful if specific markers could be employed to demonstrate and determine the quality of postmortem brain tissue that is suitable for such studies. In this chapter, the following neurochemical markers are critically reviewed as potential candidates to assess the quality of postmortem brain tissue: tryptophan levels, glutathione levels (and glutathione metabolic enzymes), enzymatic activities (glutamate decarboxylase, phosphofructokinase-1), epigenetic enzymes (acetyltransferase, methyltransferase), and tissue pH. In conclusion, the neurochemical tryptophan appears to be the most suitable candidate for assessing the integrity and quality of postmortem brain tissue. However, to optimize the quality of the samples, neuropathologic diagnostic characterization must also be employed in the interpretation and understanding of the data generated. It would also be judicious to consider as many premortem and postmortem conditions as possible as they can also affect the genetic and molecular integrity of the brain tissue.
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The Complexity of Clinical Huntington's Disease: Developments in Molecular Genetics, Neuropathology and Neuroimaging Biomarkers. ADVANCES IN NEUROBIOLOGY 2017; 15:129-161. [PMID: 28674980 DOI: 10.1007/978-3-319-57193-5_5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder characterised by extensive neuronal loss in the striatum and cerebral cortex, and a triad of clinical symptoms affecting motor, cognitive/behavioural and mood functioning. The mutation causing HD is an expansion of a CAG tract in exon 1 of the HTT gene. This chapter provides a multifaceted overview of the clinical complexity of HD. We explore recent directions in molecular genetics including the identification of loci that are genetic modifiers of HD that could potentially reveal therapeutic targets beyond the HTT gene transcript and protein. The variability of clinical symptomatology in HD is considered alongside recent findings of variability in cellular and neurochemical changes in the striatum and cerebral cortex in human brain. We review evidence from structural neuroimaging methods of progressive changes of striatum, cerebral cortex and white matter in pre-symptomatic and symptomatic HD, with a particular focus on the potential identification of neuroimaging biomarkers that could be used to test promising disease-specific and modifying treatments. Finally we provide an overview of completed clinical trials in HD and future therapeutic developments.
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Miao Y, Tepper PG, Geertsema EM, Poelarends GJ. Stereochemical Control of Enzymatic Carbon-Carbon Bond-Forming Michael-Type Additions by "Substrate Engineering". European J Org Chem 2016; 2016:5350-5354. [PMID: 27917069 PMCID: PMC5113669 DOI: 10.1002/ejoc.201601126] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Indexed: 11/19/2022]
Abstract
The enzyme 4-oxalocrotonate tautomerase (4-OT) promiscuously catalyzes the Michael-type addition of acetaldehyde to β-nitrostyrene derivatives to yield chiral γ-nitroaldehydes, which are important precursors for pharmaceutically active γ-aminobutyric acids. In this study, we investigated the effect of different substituents at the aromatic ring of the Michael acceptor on the catalytic efficiency and stereoselectivity of the 4-OT-catalyzed acetaldehyde addition reactions. Highly enantioenriched (R)- and (S)-γ-nitroaldehydes and 4-substituted chroman-2-ol could be obtained in good to excellent yields by applying different substituents at appropriate positions of the aromatic substrate. Stereochemical control of these enzymatic Michael-type additions by "substrate engineering" allowed the enantioselective synthesis of valuable γ-aminobutyric acid precursors. In addition, the results suggest a novel enzymatic synthesis route towards precursors for chromans and derivatives, which are valuable scaffolds for preparing biologically active natural products.
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Affiliation(s)
- Yufeng Miao
- Department of Chemical and Pharmaceutical BiologyGroningen Research Institute of PharmacyUniversity of GroningenAntonius Deusinglaan 19713 AVGroningenThe Netherlands
| | - Pieter G. Tepper
- Department of Chemical and Pharmaceutical BiologyGroningen Research Institute of PharmacyUniversity of GroningenAntonius Deusinglaan 19713 AVGroningenThe Netherlands
| | - Edzard M. Geertsema
- Department of Chemical and Pharmaceutical BiologyGroningen Research Institute of PharmacyUniversity of GroningenAntonius Deusinglaan 19713 AVGroningenThe Netherlands
| | - Gerrit J. Poelarends
- Department of Chemical and Pharmaceutical BiologyGroningen Research Institute of PharmacyUniversity of GroningenAntonius Deusinglaan 19713 AVGroningenThe Netherlands
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Schwarcz R. Kynurenines and Glutamate: Multiple Links and Therapeutic Implications. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2016; 76:13-37. [PMID: 27288072 PMCID: PMC5803753 DOI: 10.1016/bs.apha.2016.01.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Glutamate is firmly established as the major excitatory neurotransmitter in the mammalian brain and is actively involved in most aspects of neurophysiology. Moreover, glutamatergic impairments are associated with a wide variety of dysfunctional states, and both hypo- and hyperfunction of glutamate have been plausibly linked to the pathophysiology of neurological and psychiatric diseases. Metabolites of the kynurenine pathway (KP), the major catabolic route of the essential amino acid tryptophan, influence glutamatergic activity in several distinct ways. This includes direct effects of these "kynurenines" on ionotropic and metabotropic glutamate receptors or vesicular glutamate transport, and indirect effects, which are initiated by actions at various other recognition sites. In addition, some KP metabolites affect glutamatergic functions by generating or scavenging highly reactive free radicals. This review summarizes these phenomena and discusses implications for brain physiology and pathology.
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Affiliation(s)
- R Schwarcz
- Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, United States.
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Dowie MJ, Grimsey NL, Hoffman T, Faull RL, Glass M. Cannabinoid receptor CB2 is expressed on vascular cells, but not astroglial cells in the post-mortem human Huntington's disease brain. J Chem Neuroanat 2014; 59-60:62-71. [DOI: 10.1016/j.jchemneu.2014.06.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 05/28/2014] [Accepted: 06/16/2014] [Indexed: 01/05/2023]
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Mathew J, Invergo BJ, Silverman RB. An Efficient Synthesis of 3-Amino-4-Fluorobutanoic Acid, an Inactivator of GABA Transaminase. SYNTHETIC COMMUN 2006. [DOI: 10.1080/00397918508063815] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Abstract
Models of basal ganglia function are described which encapsulate the principal pathophysiological mechanisms underlying parkinsonian akinesia on the one hand and abnormal involuntary movement disorders (dyskinesias) on the other. In Parkinson's disease, degeneration of the nigrostriatal dopamine system leads to overactivity of the 'indirect' striatopallidal projection to the lateral (external) segment of the globus pallidus. This causes inhibition of lateral pallidal neurons, which in turn project to the subthalamic nucleus. Disinhibition of the subthalamic nucleus leads to abnormal subthalamic overactivity and, as a consequence, overactivity of medial (internal) pallidal output neurons. Dyskinesias, such as are observed in Huntington's disease, levodopa-induced dyskinesia and ballism, share mechanistic features in common and are associated with decreased neuronal activity in both the subthalamic nucleus and the medial globus pallidus.
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Affiliation(s)
- A R Crossman
- School of Biological Sciences, University of Manchester, UK
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12
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Abbruzzese G, Buccolieri A, Marchese R, Trompetto C, Mandich P, Schieppati M. Intracortical inhibition and facilitation are abnormal in Huntington's disease: a paired magnetic stimulation study. Neurosci Lett 1997; 228:87-90. [PMID: 9209105 DOI: 10.1016/s0304-3940(97)00363-7] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Transcranial magnetic stimulation with a conditioning-test paradigm was used to assess cortico-cortical interactions in the motor cortex of 11 patients with Huntington's disease (HD) as compared to normal controls (NC). In the HD patients, threshold and amplitude of motor potentials evoked in the opponens pollicis muscle at rest were not significantly different from NC. The cortico-cortical inhibition at interstimulus intervals of 2-5 ms was significantly reduced and the cortico-cortical facilitation at longer intervals (10-25 ms) was significantly enhanced. Changes of intracortical inhibition and facilitation were related to clinical rating of choreic dyskinesias. The data support the hypothesis of a functional impairment of the motor cortex-basal ganglia loop in HD patients.
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Affiliation(s)
- G Abbruzzese
- Department of Neurological Sciences and Neurorehabilitation, Genova, Italy
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Mendes MF, de Andrade LA, Ferraz HB. [Chorea: clinical analysis of 119 cases]. ARQUIVOS DE NEURO-PSIQUIATRIA 1996; 54:419-27. [PMID: 9109986 DOI: 10.1590/s0004-282x1996000300010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Chorea is a clinical syndrome characterized by abnormal involuntary arrhythmic movements, randomly distributed in time, affecting mainly the distal parts of the limbs. There are many diseases associated with chorea but the distribution of the etiologies vary too much in different parts of the world. We intended to study the etiologies of chorea in a Movement Disorders Unit of a university hospital-based outpatient clinic in Brazil. We studied the records of 119 patients with chorea based in the diagnostic criteria of the World Federation of Neurology. Sydenham's chorea (SC) was the most frequent cause of chorea (51.3%) of our sample. Other common causes were Huntington's chorea (18.5%) and chorea post-stroke (9.2%). SC is not commonly seen in developed countries nowadays but is not rare in Brazil. SC patients generally have the clinical manifestation of it in the first 20 years of age and girls are more affected than boys and this feature was observed in our sample. Based on our own experience and in the review of the literature we propose an etiological classification of chorea.
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Affiliation(s)
- M F Mendes
- Setor de Investigação em Moléstias Extrapiramidais da Disciplina de Neurologia da Escola Paulista de Medicina (EPM), Universidade Federal de São Paulo (UNIFESP), Brasil
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Storey E, Kowall NW, Finn SF, Mazurek MF, Beal MF. The cortical lesion of Huntington's disease: further neurochemical characterization, and reproduction of some of the histological and neurochemical features by N-methyl-D-aspartate lesions of rat cortex. Ann Neurol 1992; 32:526-34. [PMID: 1280937 DOI: 10.1002/ana.410320408] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Huntington's disease is a progressive neurodegenerative disease in which the basal ganglia are preferentially affected. Recent evidence, however, suggests involvement of the cerebral cortex as well, with sparing of neurochemically defined subsets of gamma-aminobutyric acid (GABA)-ergic interneurons. In the present study, we examined changes in concentrations of the amino acid neurotransmitters GABA, glutamate, and aspartate in nine cortical regions from 23 patients with advanced Huntington's disease and 12 control brains. GABA concentrations were significantly increased in eight of the nine regions, consistent with a sparing of GABAergic local circuit neurons in the context of progressive cortical atrophy. Small but significant increases in glutamate were found in six of the nine regions, while aspartate levels were generally unaffected. Striate cortex (Brodmann's area 17) showed the most profound increases in GABA and glutamate. We also investigated the effects of powdering the excitotoxins N-methyl-D-aspartate (NMDA) or kainic acid onto the dura of rats. The resulting lesions were examined at 1 week and 6 months. The NMDA-induced lesions showed striking sparing of parvalbumin-positive neurons (a subset of GABAergic interneurons), and this sparing was reflected in neurochemical measurements of GABA; kainic acid lesions failed to display this selectivity. Somatostatin, cholecystokinin, and vasoactive intestinal polypeptide concentrations were spared by the NMDA-induced lesions, and substance P levels were significantly increased. These results provide evidence that NMDA excitotoxic lesions of cerebral cortex can produce a selective pattern of neuronal damage similar to that which occurs in Huntington's disease.
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Affiliation(s)
- E Storey
- Neurochemistry Laboratory, Massachusetts General Hospital, Boston 02114
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15
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Iskander MN, Andrews PR, Winkler DA, Brinkworth RI, Di Paola C, Cavell S, Issa J. Transition-state analogues as inhibitors for GABA-aminotransferase. Eur J Med Chem 1991. [DOI: 10.1016/0223-5234(91)90022-f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Peyser CE, Folstein SE. Huntington's disease as a model for mood disorders. Clues from neuropathology and neurochemistry. MOLECULAR AND CHEMICAL NEUROPATHOLOGY 1990; 12:99-119. [PMID: 2149928 DOI: 10.1007/bf03160062] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Huntington's disease (HD) is an inherited neuropsychiatric degenerative process characterized by movement disorder, dementia, and, often, affective disorder (AfD) (seen in 38% of patients). Depression in HD is not just an understandable reaction to fatal illness: 10% of HD patients develop mania; AfD can occur 20 yr before neurological signs; and mood disorders are not randomly distributed, but occur in a subset of HD families. This evidence suggests that AfD in HD relates to brain pathophysiology. With its clear neuropathology, HD is proposed as one model for biological underpinnings of idiopathic AfD. There is striking atrophy and neuronal loss in HD neostriatum, particularly caudate. Caudate has rich connections to the limbic system. It is hypothesized that AfD in HD relates to dysfunction of the part of the neostriatum damaged earliest, dorsal medial caudate. Preliminary studies on neuropathological differences between HD patients with and without AfD are discussed. HD neurochemistry is reviewed, emphasizing the excitotoxin hypothesis, which involves dysfunction of the glutamate neurotransmitter system in HD (especially the NMDA receptor, which contains a channel with a phencyclidine (PCP) binding site). Based on the HD model, it is suggested that the glutamate system (particularly NMDA receptors) be examined in idiopathic AfD.
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Affiliation(s)
- C E Peyser
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD 21205
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17
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Gulya K. The opioid system in neurologic and psychiatric disorders and in their experimental models. Pharmacol Ther 1990; 46:395-428. [PMID: 2188270 DOI: 10.1016/0163-7258(90)90026-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Evidence from experimental and clinical studies suggests the involvement of the endogenous opioid system in several neurologic and psychiatric disorders (Alzheimer's, Huntington's and Parkinson's diseases, drug-induced movement disorders, Gilles de la Tourette syndrome, stroke, ischemia, brain and spinal cord injury, epilepsy, schizophrenia and affective disorders). However, its involvement is rather a secondary one, perhaps being a severe consequence of a primary, nonopioid disturbance. Thus, treatment of an opioidergic manifestation of a disorder of nonopioidergic origin is necessarily symptomatic and targets only the restoration of the opioid system; such treatment may be beneficial in ameliorating the clinical symptoms of the disorder.
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Affiliation(s)
- K Gulya
- Central Research Laboratory, Albert Szent-Györgyi Medical University, Szeged, Hungary
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18
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Goety CG, Tanner CM, Cohen JA, Thelen JA, Carroll VS, Klawans HL, Fariello RG. L-acetyl-carnitine in Huntington's disease: double-blind placebo controlled crossover study of drug effects on movement disorder and dementia. Mov Disord 1990; 5:263-5. [PMID: 2143808 DOI: 10.1002/mds.870050317] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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Abstract
In the central nervous system and particularly in the striatum of patients with Huntington's disease (HD) a dramatic cell loss can be observed. Animal models of HD are based on intrastriatal injection of excitatory amino acids (EAAs). Stimulation of EAA receptors for a prolonged period of time degenerates the cells on which the EAA receptors are located, a phenomenon known as excitotoxicity. Several categories of EAA receptors, viz. quisqualate, kainate and N-methyl-D-aspartate (NMDA), have been identified in the central nervous system. Interestingly, quinolinic acid, a metabolite of tryptophan along the kynurenine pathway, appeared to be an agonist on the NMDA receptor and a potent excitotoxin. Indications have been reported, although still controversial, for derangements in the formation of quinolinic acid to occur in the brains of patients with HD. Based on these studies the likeliness of a role for quinolinic acid in the etiology of HD is evaluated.
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Affiliation(s)
- R P Bruyn
- Department of Neurology, Medical Faculty, Free University, Amsterdam, The Netherlands
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20
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Crossman AR. Neural mechanisms in disorders of movement. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. A, COMPARATIVE PHYSIOLOGY 1989; 93:141-9. [PMID: 2568216 DOI: 10.1016/0300-9629(89)90201-6] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
1. Experimental models of ballism, chorea and Parkinson's disease have been developed in the primate, and the underlying neural mechanisms which mediate these disorders of movement have been investigated using the 2-deoxyglucose uptake technique. 2. In ballism, the subthalamic nucleus is either lesioned or underactive. Because of the excitatory nature of subthalamic efferent fibres, this leads to abnormal underactivity of neurons in the medical segment of the globus pallidus which project to the ventral anterior and ventral lateral nuclei of the thalamus, and to the pedunculopontine nucleus of the caudal midbrain. 3. In chorea, there is underactivity of GABAergic striatal (putaminal) neurons which project to the lateral segment of the globus pallidus. This leads to overacting of lateral pallidal neurons and, thus, physiological inhibition of the subthalamic nucleus. Common neural mechanisms, therefore, underlie the appearance of dyskinesia in ballism and chorea. 4. In parkinsonism, there is overactivity of putaminal neurons projecting to the lateral pallidal segment. This results in excessive inhibition of lateral pallidal neurons and, as a consequence, disinhibition of the subthalamic nucleus. Overactivity of the subthalamic nucleus provides excessive drive upon medial pallidal neurons projecting to thalamic and pedunculopontine nuclei.
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Affiliation(s)
- A R Crossman
- Department of Cell and Structural Biology, Medical School, University of Manchester, UK
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21
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Ball JA, Burnet PW, Bretherton-Watt D, Bloom SR. Increase in diazepam binding inhibitor-like immunoreactivity (51-70) in Huntington's disease. J Neurol Sci 1988; 88:177-84. [PMID: 2852215 DOI: 10.1016/0022-510x(88)90215-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In Huntington's disease (HD), reduction in striatal GABA is one of the most striking abnormalities and alterations in benzodiazepine receptors, which are allosterically linked to the GABAA receptor, have also been reported. Diazepam binding inhibitor (DBI), recently isolated from rat and human brain, has been proposed as an endogenous ligand at the benzodiazepine receptor. The content of DBI-like immunoreactivity(51-70) (DBI-IR(51-70), has therefore been compared in control postmortem human brains and in HD brains (matched for age, sex and post-mortem delay), using a specific radioimmunoassay. DBI-IR(51-70) was more than 1.5-fold increased in the putamen, caudate, globus pallidus and nucleus accumbens of HD brains compared to the control group (P less than 0.001). Gel filtration chromatography showed similar elution profiles of the peptide in both control and HD extracts, thus providing no evidence for a change in the nature of the peptide itself.
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Affiliation(s)
- J A Ball
- Department of Medicine, Royal Postgraduate Medical School, Hammersmith Hospital, London, U.K
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Ebadi M, Hama Y. Dopamine, GABA, cholecystokinin and opioids in neuroleptic-induced tardive dyskinesia. Neurosci Biobehav Rev 1988; 12:179-87. [PMID: 2906420 DOI: 10.1016/s0149-7634(88)80039-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The long-term administration of neuroleptics causes tardive dyskinesia, which closely resembles levodopa-induced dyskinesias, and is brought about through complex mechanisms which are ill-defined. It is generally believed that the pathogenesis of tardive dyskinesia relates closely to the chronic blockade of dopamine receptor sites and that its pathophysiology results from a hypersensitivity of dopamine receptor sites. In the therapeutic management of neuroleptic-induced tardive dyskinesia, in addition to reserpine and lithium, diazepam, baclofen, or gamma-vinyl-gamma-aminobutyric acid have also been advocated. However, the reported beneficial effects of diazepam and GABA-mimetic agents in ameliorating the symptoms of tardive dyskinesia may occur through a mechanism which does not necessarily link transmission involving both dopamine and GABA. The presence of high concentrations of both cholecystokinin and opioids in the striatum also suggests that these peptides not only may influence dopaminergic transmission, but that they may also be relevant to the psychopathology of schizophrenia and to the therapeutic effects of neuroleptics. Indeed, the acute and chronic administration of neuroleptics alters the levels of cholecystokinin and opioids and their receptors in several brain regions including the striatum. However, neuroleptics also alter the biochemical integrity of neurotensin, neuropeptide Y, substance P and somatostatin, which may also play a role in the overall expression of the neuroleptic-induced extrapyramidal reactions.
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Affiliation(s)
- M Ebadi
- Department of Pharmacology, University of Nebraska College of Medicine, Omaha 68105
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Roberts RC, Difiglia M. Localization of immunoreactive GABA and enkephalin and NADPH-diaphorase-positive neurons in fetal striatal grafts in the quinolinic-acid-lesioned rat neostriatum. J Comp Neurol 1988; 274:406-21. [PMID: 2975675 DOI: 10.1002/cne.902740309] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Fetal striatal tissue grafts have been shown to partially reverse the biochemical and behavioral deficits induced by excitotoxic lesions. To determine if grafted striatal neurons contain neurochemical markers similar to those in neurons in the caudate nucleus and to establish the morphological characteristics and relative frequency of labeled neurons in the grafts, the localization of immunoreactive GABA and leucine-enkephalin (ENK) and of NADPH-diaphorase (NADPH-d) activity was examined in fetal striatal grafts at the light and electron microscopic levels. Striatal tissue from 17-day fetuses was grafted into the caudate nucleus of adult rats 1 week after intracaudate injections of either a low or high dose of quinolinic acid. At the light microscopic level, immunoreactive GABA and ENK and NADPH-d-positive neurons, processes, and punctate structures were present within adjacent sections of the same grafts. The frequency and morphological features of these labeled cell populations were similar in grafts placed into either minimally or extensively lesioned striata. Immunoreactive GABA and ENK neurons in the grafts constituted 28% and 13.5%, respectively, of the neuronal population of the graft and their mean diameters were 22 and 14% larger, respectively, than neostriatal neurons that contained the same chemical markers. NADPH-d-positive neurons in the grafts formed 3.5% of total grafted neurons and exhibited characteristics of neostriatal NADPH-d-containing aspiny cells, including medium-sized somata, indented nuclei, and varicose dendrites. At the electron microscopic level most GABA-positive neurons in the grafts contained indented nuclei and most immunoreactive ENK somata had unindented nuclei. Dendrites and dendritic spines with GABA or ENK immunoreactivity were present in the grafts where they were postsynaptic to unlabeled axons. Immunoreactive GABA and ENK axon terminals formed synapses with unlabeled neuronal profiles in the grafts. These findings demonstrate that fetal striatal grafts contain chemically defined neuronal populations that form synaptic connections within the graft and share some features with corresponding cell groups in the neostriatum. These results provide an anatomical basis for the graft-induced recovery from behavioral and biochemical deficits caused by instrastriatal lesions reported in other studies.
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Affiliation(s)
- R C Roberts
- Department of Neurology, Massachusetts General Hospital, Boston 02114
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Abstract
We studied the levels of free amino acids in putamen and Brodmann's area 10 of 12 patients who died with Huntington's disease and 13 non-neurologic controls. GABA, glutamate and alpha-amino-n-butyric acid concentrations were found to be reduced in putamen of Huntington's disease patients. In Brodmann's area 10 the levels of glutamate, histidine and lysine were decreased, but the content of aspartate, GABA, glycine, serine and taurine was increased in the same group of patients.
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Affiliation(s)
- E Bonilla
- Instituto de Investigaciones Clinicas, Universidad del Zulia, Maracaibo, Venezuela
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Crossman AR. Primate models of dyskinesia: the experimental approach to the study of basal ganglia-related involuntary movement disorders. Neuroscience 1987; 21:1-40. [PMID: 2955248 DOI: 10.1016/0306-4522(87)90322-8] [Citation(s) in RCA: 216] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Bonnet AM, Tell G, Schechter PJ, Grove J, Saint-Hilaire MH, De Smet Y, Agid Y. Cerebrospinal fluid GABA and homocarnosine concentrations in patients with Friedreich's ataxia, Parkinson's disease, and Huntington's chorea. Mov Disord 1987; 2:117-23. [PMID: 2973560 DOI: 10.1002/mds.870020206] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Free and total gamma-aminobutyric acid (GABA) and homocarnosine concentrations were measured in the lumbar cerebrospinal fluid (CSF) of patients with Friedreich's ataxia, Huntington's chorea, and Parkinson's disease (with and without levodopa treatment), and compared with those determined in control subjects. Values found in Friedreich's ataxia or Parkinson's disease were not significantly different from those in controls. Unexpectedly, in Huntington patients, known to have a characteristic decrease in GABA concentrations in specific brain areas, CSF concentrations of total GABA and homocarnosine were significantly higher, whereas free GABA was not different from controls. These findings indicate that the measurement of CSF GABA and homocarnosine in patients with CNS degenerative diseases should be interpreted cautiously.
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Affiliation(s)
- A M Bonnet
- Clinique de Neurologie et de Neuropsychologie, INSERM (U 289), Hopital de la Salpétrière, Paris, France
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Hama Y, Ebadi M. The nullification by diazepam of haloperidol-induced increases in the level of striatal dopamine but not in the activity of glutamic acid decarboxylase. Neuropharmacology 1986; 25:1235-42. [PMID: 3796796 DOI: 10.1016/0028-3908(86)90141-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In the therapeutic management of neuroleptic-induced tardive dyskinesia, diazepam, baclofen or gamma-vinyl-gamma-aminobutyric acid have been advocated. It has been postulated, but not proven, that the beneficial effects of these agents in tardive dyskinesia may be mediated by enhancing GABAergic transmission. In this study, it is reported that, during a 3-day withdrawal period following daily administration of 3 mg/kg of haloperidol (i.p.) for 3 weeks, the activity of glutamic acid decarboxylase in the striatum increased from 72.6 +/- 7.8 to 92.5 +/- 10.2 nmol 14CO2/mg protein/hr, and the concentration of dopamine in the striatum increased from 7.87 +/- 0.23 to 8.86 +/- 0.38 micrograms/g wet tissue. Diazepam (5 mg/kg, i.p.), given during the withdrawal period from haloperidol was able to nullify the enhancement in the concentration of dopamine but not in the activity of glutamic acid decarboxylase in the striatum. The results of these studies are interpreted to indicate that the reported beneficial effects of diazepam and GABA-mimetic agents in ameliorating the symptoms of tardive dyskinesia may occur through a mechanism which does not necessarily link transmission involving both dopamine and GABA.
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Abstract
Of all the movement disorders, Huntington's disease has been most consistently associated with dementia, while it is only over the last decade that intellectual cognitive decline have been recognized as common features of Parkinson's disease. It is now known that the pathology in these two conditions reflects differential involvement of the striatum. The Huntington lesion is primarily in the caudate, while the Parkinson lesion preferentially affects the putamen. Both conditions have more diffuse pathology, and dementia may also occur in a wide range of other extrapyramidal diseases, such as progressive supranuclear palsy, the parkinsonism-dementia complex of Guam, and certain spinocerebellar degenerations. Clinicopathological correlations will be reviewed in these disorders of primarily subcortical pathology, and comparisons will be made with Alzheimer's disease, a disorder of predominantly cortical pathology.
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30
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Mann JJ, Kaplan RD, Bird ED. Elevated postmortem monoamine oxidase B activity in the caudate nucleus in Huntington's disease compared to schizophrenics and controls. J Neural Transm (Vienna) 1986; 65:277-83. [PMID: 2940336 DOI: 10.1007/bf01249088] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Activity (Vmax) of monoamine oxidase (MAO) B in necropsy samples from the head of the caudate nucleus was 260% higher in patients dying with Huntington's disease (HD) than in controls (P less than 0.05). No differences in MAO A enzyme kinetics were found. MAO B, but not MAO A, was increased (26%) in the frontal cortex from patients dying with HD compared to control subjects. MAO A and B kinetics in caudate nucleus and frontal cortex from a group of schizophrenics did not differ from controls. Postmortem delay, the effect of neuroleptics, or nonspecific degeneration artifacts did not explain these findings. It is suggested that the increase in MAO B activity in the caudate nucleus may reflect neurochemical changes that are responsible for the choreiform movements of Huntington's disease. Lower cortical MAO B activity in the schizophrenic group may reflect the effects of neuroleptics.
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Tunnicliff G, Ngo TT. Regulation of γ-aminobutyric acid synthesis in the vertebrate nervous system. Neurochem Int 1986; 8:287-97. [DOI: 10.1016/0197-0186(86)90002-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/1985] [Accepted: 10/16/1985] [Indexed: 11/29/2022]
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Borison RL, Hitri A, Diamond BI. Biochemical and Pharmacological Aspects of Movement Disorders in Huntington’s Disease. Mov Disord 1986. [DOI: 10.1007/978-1-4684-5038-5_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Interactions of gamma-aminobutyric acid (GABA), pentobarbital, and homopantothenic acid (HOPA) on internally perfused frog sensory neurons. Cell Mol Neurobiol 1985; 5:245-55. [PMID: 2415258 DOI: 10.1007/bf00711010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Augmentatory actions among Cl- currents (ICl) induced by gamma-aminobutyric acid (GABA), pentobarbital (PB), and homopantothenic acid (HOPA) were investigated in isolated frog sensory neurons after suppression of Na+, K+, and Ca2+ currents using a suction pipette technique which combines internal perfusion with voltage clamp. GABA-sensitive neurons responded to both PB and HOPA, and the responses behaved as a simple Cl- electrode and reversed at the Cl- equilibrium potential (ECl). The dose-response curve for GABA-induced Cl- conductance was sigmoidal with the GABA concentration producing a half-maximum response (4.2 X 10(-5) M). Both GABA and HOPA dose-response curves shifted to the left in the presence of PB, though the facilitatory action of PB on GABA- and HOPA-induced ICl was more effective in the former. There was a significant facilitatory interaction between GABA- and HOPA-induced ICl. It is concluded that HOPA affects the GABA-GABA or PB-PB receptor interactions.
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35
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Perry TL, Yong VW, Hansen S, Foulks JG, Kish SJ. Is a circulating neurotoxin involved in the pathogenesis of Huntington's chorea? J Neurol Sci 1985; 67:351-8. [PMID: 3157785 DOI: 10.1016/0022-510x(85)90160-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We tested the hypothesis that the premature neuronal death which occurs in Huntington's chorea (HC) might be the result of a genetically-determined enzymatic failure in the degradation of a circulating neurotoxin of either endogenous of exogenous origin. Infant rats were given daily subcutaneous injections of large quantities of whole serum (for 24 days), or of a concentrated serum ultrafiltrate (for 37 days), obtained from HC patients or control subjects. Animals were killed 4 months after the end of injections, and their striata were examined neurochemically. There was a significant but small (16%) reduction in the mean striatal content of gamma-aminobutyric acid (GABA) in rats treated with whole serum from HC patients, but no striatal GABA deficiency was observed in rats treated with ultrafiltrates of serum from HC patients. Nor did these rats have any reduction in their striatal choline acetyltransferase activity. We conclude that if a circulating neurotoxin does contribute to the pathogenesis of HC, it must either be a small molecule which is tightly bound to serum proteins, or less likely a large compound with a molecular weight greater than 10 000.
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36
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Minuk GY, Vergalla J, Ferenci P, Jones EA. Identification of an acceptor system for gamma-aminobutyric acid on isolated rat hepatocytes. Hepatology 1984; 4:180-5. [PMID: 6323294 DOI: 10.1002/hep.1840040203] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
gamma-Aminobutyric acid (GABA) is a potent inhibitory neurotransmitter which is synthesized by the enteric bacterial flora and delivered into portal venous blood. To determine whether the liver is likely to play an important role in regulating serum GABA levels, the uptake and metabolism of [3H]GABA by three populations of cells isolated from rat liver were studied. GABA was specifically taken up by hepatocytes but not by endothelial or Kupffer cells. Uptake by hepatocytes was saturable, as well as time and sodium dependent. At 0.5 degrees C, a temperature at which binding of GABA to the cell surface is considered to be the predominant component of the uptake process, the apparent affinity constant (Km) was 0.82 microM and a minimum value for binding velocity (Vmax) was 0.13 microM per min per 5 X 10(5) cells. Uptake of [3H]GABA by hepatocytes was markedly inhibited by excess unlabeled GABA (95%), alpha-aminoisobutyric acid (66%) and bicuculline (58%), but was inhibited much less by alanine (16%) and leucine (29%). These findings suggest that GABA binds specifically to the high affinity acceptor of the A amino acid transport system of rat hepatocytes. Impaired function of this transport system in liver failure could contribute to increased circulating levels of GABA.
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Gardner CR, Mallorga P, Klein J, Huot-Olivier S, Palfreyman MG. Chronic elevation of brain GABA by gamma-vinyl GABA treatment does not alter the sensitivity of GABAergic or dopaminergic receptors in rat CNS. Psychopharmacology (Berl) 1983; 79:130-6. [PMID: 6302725 DOI: 10.1007/bf00427799] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Rat brain GABA levels were elevated chronically by daily administration of gamma-vinyl GABA, an enzyme-activated, irreversible inhibitor of GABA:2-oxo-glutarate aminotransferase (GABA-T; EC2.6.1.19). Following various periods of drug treatment and withdrawal, the sensitivity of dopamine and GABA receptors in the CNS was determined by biochemical and behavioral evaluations. In contrast to chronic haloperidol treatment, none of the treatment schedules with gamma-vinyl GABA had any significant effect on parameters such as apomorphine induced locomotor activity, [3H] spiperone binding or dopamine-stimulated adenylate cyclase in the corpus striatum; nor did gamma-vinyl GABA treatment affect [3H] GABA binding or GABA-activated [3H] diazepam binding in the cerebral cortex. Moreover, co-administration of gamma-vinyl GABA and haloperidol did not alter the ability of the neuroleptic to induce supersensitivity in the striatal dopaminergic system. Thus, it appears that, in contrast to reported studies using chronic administration of other less specific GABA-T inhibitors such as gamma-acetylenic GABA, amino-oxyacetic acid and isonicotinic acid hydrazide or direct GABA agonists such as THIP (4,5,6,7-tetrahydroisoxazolo (5,4-c-)-pyridin-3-ol) or kojic amine, gamma-vinyl GABA does not alter the sensitivity of the striatal dopaminergic system.
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38
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Banerjee A, Turner AJ, Guha SR. GABA dehydrogenase activity in rat brain. Biochem Pharmacol 1982; 31:3219-23. [PMID: 7150350 DOI: 10.1016/0006-2952(82)90553-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The crude mitochondrial fraction of rat brain contains an active dehydrogenase involved in the direct oxidation of gamma-aminobutyric acid. INT (p-iodonitrotetrazolium violet) can serve as an efficient acceptor of electrons in this dehydrogenase reaction. During this oxidation of GABA, ammonia is not produced. In vitro the dehydrogenase activity is inhibited by certain MAO inhibitors. The effects of various inhibitors of GABA-T and GAD were also investigated. The dehydrogenase activity was found to be susceptible to various anti-convulsants and inhibitors of electron transport. The co-factors which may be involved in the transfer of electrons during GABA oxidation in the presence of INT are also discussed.
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39
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Abstract
The entry of GABA into cerebrospinal fluid (CSF) was studied in dogs anesthetized with pentobarbital and relaxed with suxamethonium. GABA was administered intravenously as a priming dose and subsequent maintenance infusion to compensate for the rapid elimination of the amino acid. Steady state concentrations of GABA in CSF were reached between 10 and 60 min after injection, the rate of entry tending to decrease with increasing plasma levels. During steady state conditions CSF concentrations showed great interindividual differences and varied between 0.03 and 5.1% of those in plasma. Probenecid and sodium valproate considerably enhanced the CSF/plasma concentration ratio of GABA. When GABA was directly injected into the liquor space, probenecid slowed down the elimination of GABA from CSF. The results suggest a transport of GABA into and out of CSF, the outward transport being inhibited by probenecid and sodium valproate.
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40
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Bruyn GW. Neurotransmitters in Huntington's Chorea--a clinician's view. PROGRESS IN BRAIN RESEARCH 1982; 55:445-64. [PMID: 6131480 DOI: 10.1016/s0079-6123(08)64214-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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41
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Abstract
1. Introduction of radioligand binding techniques has opened new possibilities in the study of the biological basis of psychiatric disorders. 2. The possible role of CNS receptors in schizophrenia, depression, anxiety, Huntington's disease and Alzheimer's dementia is discussed. 3. Data are presented in a systematic manner starting with the identification of receptors which appear to be the primary locus of action of drugs currently used in the treatment of these disorders. 4. A review of the data on the changes in receptor levels and/or affinity that might be associated with the respective disease follows. 5. Changes in receptor number and/or affinity after chronic drug therapy are outlined and the possible utilization of radioligand binding techniques in drug plasma level determination is discussed.
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42
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Abstract
In 23 children with febrile convulsions the concentration of gamma-aminobutyric acid (GABA) in lumbar cerebrospinal fluid (CSF) was measured by a radioreceptor assay. The mean CSF GABA concentration of 134 (range, 73-294) pmoles/ml was significantly lower than that of 16 seizure-free children serving as controls, who had 210 (range, 117-475) pmoles/ml. The reduction in CSF GABA levels in patients with febrile convulsions was not reflected in plasma GABA concentrations. These data provide further evidence that impairment of GABA neurotransmission may contribute to an increased seizure propensity.
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43
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Dodd P, Hardy JA, Oakley AE, Strong AJ. Synaptosomes prepared from fresh human cerebral cortex; morphology, respiration and release of transmitter amino acids. Brain Res 1981; 224:419-25. [PMID: 6116530 DOI: 10.1016/0006-8993(81)90871-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Synaptosomes prepared from fresh human cerebral cortex were shown to be morphologically similar to those from other species. On incubation, they took up oxygen at a high and linear rate and accumulated potassium against a concentration gradient. In response to depolarization by raised extracellular K+ or addition of veratrine, they showed increased respiration, lowered tissue potassium, and enhanced release of glutamate, aspartate and GABA. The preparation may be of value for studies of neurological disorders.
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44
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Hare TA. Alterations of central GABAergic activity in neurologic and psychiatric disorders: evaluation through measurements of GABA and GAD activity in cerebrospinal fluid. Mol Cell Biochem 1981; 39:297-304. [PMID: 7031462 DOI: 10.1007/bf00232581] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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45
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Perry TL, Hansen S, Kish SJ, MacLean J, Berry K. Rats chronically injected with urine from Huntington's chorea patients do not striatal damage. Life Sci 1981; 28:2869-74. [PMID: 6455580 DOI: 10.1016/0024-3205(81)90103-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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46
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Zimmer R, Teelken AW, Meier KD, Ackenheil M, Zander KJ. Preliminary studies on CSF gamma-aminobutyric acid levels in psychiatric patients before and during treatment with different psychotropic drugs. PROGRESS IN NEURO-PSYCHOPHARMACOLOGY 1981; 4:613-20. [PMID: 7220676 DOI: 10.1016/0364-7722(81)90103-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Abstract
Because of the usually late onset of Huntington's disease (HD) most sufferers have reproduced and passed the HD gene to about one half of their offspring before they themselves develop symptoms of the disease. Genetic counseling of persons at risk of HD would be greatly facilitated if the gene could be detected presymptomatically. At present, there is no suitable predictive test for HD, but many approaches currently being investigated show some promise. These approaches are reviewed and critically evaluated.
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Böhlen P, Tell G, Schechter PJ, Koch-Weser J, Agid Y, Coquillat G, Chazot G, Fischer C. Cerebrospinal fluid homocarnosine in Huntington's disease. Life Sci 1980; 26:1009-12. [PMID: 6446633 DOI: 10.1016/0024-3205(80)90244-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Röytta M, Laaksonen H, Frey H, Riekkinen P, Rinne UK. Critical evaluation of the postmortem factors influencing neurochemical analyses of brain autopsies. Acta Neurol Scand 1980; 61:88-106. [PMID: 6104885 DOI: 10.1111/j.1600-0404.1980.tb01471.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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50
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