1
|
Nguyen H, Glaaser IW, Slesinger PA. Direct modulation of G protein-gated inwardly rectifying potassium (GIRK) channels. Front Physiol 2024; 15:1386645. [PMID: 38903913 PMCID: PMC11187414 DOI: 10.3389/fphys.2024.1386645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 04/08/2024] [Indexed: 06/22/2024] Open
Abstract
Ion channels play a pivotal role in regulating cellular excitability and signal transduction processes. Among the various ion channels, G-protein-coupled inwardly rectifying potassium (GIRK) channels serve as key mediators of neurotransmission and cellular responses to extracellular signals. GIRK channels are members of the larger family of inwardly-rectifying potassium (Kir) channels. Typically, GIRK channels are activated via the direct binding of G-protein βγ subunits upon the activation of G-protein-coupled receptors (GPCRs). GIRK channel activation requires the presence of the lipid signaling molecule, phosphatidylinositol 4,5-bisphosphate (PIP2). GIRK channels are also modulated by endogenous proteins and other molecules, including RGS proteins, cholesterol, and SNX27 as well as exogenous compounds, such as alcohol. In the last decade or so, several groups have developed novel drugs and small molecules, such as ML297, GAT1508 and GiGA1, that activate GIRK channels in a G-protein independent manner. Here, we aim to provide a comprehensive overview focusing on the direct modulation of GIRK channels by G-proteins, PIP2, cholesterol, and novel modulatory compounds. These studies offer valuable insights into the underlying molecular mechanisms of channel function, and have potential implications for both basic research and therapeutic development.
Collapse
Affiliation(s)
| | | | - Paul A. Slesinger
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| |
Collapse
|
2
|
Li J, Mei S, Mao X, Wan L, Wang H, Xiao B, Song Y, Gu W, Liu Y, Long L. De novo variants in KCNJ3 are associated with early-onset epilepsy. J Med Genet 2024; 61:319-324. [PMID: 37963718 DOI: 10.1136/jmg-2023-109201] [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: 02/06/2023] [Accepted: 10/14/2023] [Indexed: 11/16/2023]
Abstract
BACKGROUND KCNJ3 encodes a subunit of G-protein-coupled inwardly rectifying potassium channels, which are important for cellular excitability and inhibitory neurotransmission. However, the genetic basis of KCNJ3 in epilepsy has not been determined. This study aimed to identify the pathogenic KCNJ3 variants in patients with epilepsy. METHODS Trio exome sequencing was performed to determine potential variants of epilepsy. Individuals with KCNJ3 variants were recruited for this study. Detailed clinical information and genetic data were obtained and systematically reviewed. Whole-cell patch-clamp recordings were performed to evaluate the functional consequences of the identified variants. RESULTS Two de novo missense variants (c.998T>C (p.Leu333Ser) and c.938G>A (p. Arg313Gln)) in KCNJ3 were identified in two unrelated families with epilepsy. The variants were absent from the gnomAD database and were assumed to be damaging or probably damaging using multiple bioinformatics tools. They were both located in the C-terminal domain. The amino acid residues were highly conserved among various species. Clinically, the seizures occurred at a young age and were under control after combined treatment. Electrophysiological analysis revealed that the KCNJ3 Leu333Ser and Arg313Gln variants significantly compromised the current activities and exhibited loss-of-function (LOF) effects. CONCLUSION Our findings suggest that de novo LOF variants in KCNJ3 are associated with early-onset epilepsy. Genetic testing of KCNJ3 in patients with epilepsy may serve as a strategy for precision medicine.
Collapse
Affiliation(s)
- Juan Li
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, Hunan, China
| | - Shiyue Mei
- Henan Provincial Key Laboratory of Children's Genetics and Metabolic Diseases, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan, China
| | - Xiao Mao
- Department of Medical Genetics, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China
- National Health Commission Key Laboratory for Birth Defect Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China
| | - Lily Wan
- Department of Anatomy & Neurobiology, Central South University Xiangya School of Medicine, Changsha, Hunan, China
| | - Hua Wang
- Department of Medical Genetics, Hunan Children's Hospital, Changsha, Hunan, China
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, Hunan, China
| | - Yanmin Song
- Department of Emergency Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Weiyue Gu
- Chigene (Beijing) Translational Medical Research Center Co. Ltd, Beijing, China
| | - Yan Liu
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Lili Long
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, Hunan, China
| |
Collapse
|
3
|
Park H, Kim T, Kim J, Yamamoto Y, Tanaka-Yamamoto K. Inputs from Sequentially Developed Parallel Fibers Are Required for Cerebellar Organization. Cell Rep 2019; 28:2939-2954.e5. [DOI: 10.1016/j.celrep.2019.08.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 06/10/2019] [Accepted: 07/30/2019] [Indexed: 11/15/2022] Open
|
4
|
Brandalise F, Lujan R, Leone R, Lodola F, Cesaroni V, Romano C, Gerber U, Rossi P. Distinct expression patterns of inwardly rectifying potassium currents in developing cerebellar granule cells of the hemispheres and the vermis. Eur J Neurosci 2016; 43:1460-73. [DOI: 10.1111/ejn.13219] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 02/14/2016] [Accepted: 02/23/2016] [Indexed: 11/29/2022]
Affiliation(s)
- Federico Brandalise
- Department of Biology and Biotechnology; University of Pavia; via Ferrata 9 27100 Pavia Italy
- Brain Research Institute; University of Zurich; Zurich Switzerland
| | - Rafael Lujan
- Instituto de Investigación en Discapacidades Neurológicas (IDINE); Department of Ciencias Médicas; Facultad de Medicina; Universidad Castilla-La Mancha; Albacete Spain
| | - Roberta Leone
- Brain Research Institute; University of Zurich; Zurich Switzerland
| | - Francesco Lodola
- Molecular Cardiology; IRCCS Fondazione Salvatore Maugeri; Pavia Italy
| | - Valentina Cesaroni
- Department of Biology and Biotechnology; University of Pavia; via Ferrata 9 27100 Pavia Italy
| | - Chiara Romano
- Department of Biology and Biotechnology; University of Pavia; via Ferrata 9 27100 Pavia Italy
| | - Urs Gerber
- Brain Research Institute; University of Zurich; Zurich Switzerland
| | - Paola Rossi
- Department of Biology and Biotechnology; University of Pavia; via Ferrata 9 27100 Pavia Italy
| |
Collapse
|
5
|
Generation and vulnerability of deep cerebellar nuclei neurons in the weaver condition along the anteroposterior and mediolateral axes. Int J Dev Neurosci 2016; 49:37-45. [PMID: 26748014 DOI: 10.1016/j.ijdevneu.2015.12.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 12/28/2015] [Accepted: 12/28/2015] [Indexed: 02/02/2023] Open
Abstract
Production and death of deep cerebellar nuclei (DCN) neurons were investigated in the weaver condition at appropriate anatomical levels throughout the mediolateral (medial, intermediate and lateral) and rostrocaudal (rostral, middle and caudal) axes of three DCN-cell groups: the fastigial, the interposed and the dentate nuclei. Current results have denoted that the deficit of DCN neurons is always more important in the homozygous weaver than in the heterozygous weaver mice. No loss of neurons was found in the dentate nucleus. In the mediolateral axis, an intranuclear gradient of depletion was observed in the mutant mice; in a given deep nucleus, neurodegeneration was more prominent in the medial pars than in lateral ones. In the rostrocaudal axis, on the other hand, when each deep nucleus was studied and compared as a whole, neuron loss was higher in the fastigial nucleus than in the interposed nucleus, which, in turn, was more important than in the dentate nucleus. These data suggest that, in the weaver condition, an internuclear gradient of neurodegeneration exists. Moreover, neurons located in rostral parts of a given nucleus appear to be more vulnerable than those settled in middle parts and these, in turn, are more than the caudal ones. These results seem to indicate the presence of an intranuclear gradient of depletion. Current autoradiographic results have revealed that, in the rostrocaudal axis, deep neurons are settled in the weaver cerebellum following three neurogenetic gradients. The first of these is internuclear; if each deep nucleus is analyzed and compared as a whole, the fastigial nucleus has more late-generated neurons than the interposed nucleus, and this, in turn, has more than the dentate nucleus. The second gradient is also internuclear; if the proportion of late-born neurons is compared throughout the rostral levels from each deep nucleus, it is observed that proportions increase from the fastigial to the dentate nucleus. A similar picture emerges when the middle and caudal regions are taken into account. The third gradient is intranuclear; in a given deep nucleus, the rostral region always presents more late-produced neurons than the middle region and these, in turn, more than in the caudal level.
Collapse
|
6
|
Cookman CJ, Belcher SM. Estrogen Receptor-β Up-Regulates IGF1R Expression and Activity to Inhibit Apoptosis and Increase Growth of Medulloblastoma. Endocrinology 2015; 156:2395-408. [PMID: 25885794 PMCID: PMC4475721 DOI: 10.1210/en.2015-1141] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Medulloblastoma (Med) is the most common malignant brain tumor in children. The role of ESR2 [estrogen receptor (ER)-β] in promoting Med growth was comprehensively examined in three in vivo models and human cell lines. In a novel Med ERβ-null knockout model developed by crossing Esr2(-/-) mice with cerebellar granule cell precursor specific Ptch1 conditional knockout mice, the tumor growth rate was significantly decreased in males and females. The absence of Esr2 resulted in increased apoptosis, decreased B-cell lymphoma 2 (BCL2), and IGF-1 receptor (IGF1R) expression, and decreased levels of active MAPKs (ERK1/2) and protein kinase B (AKT). Treatment of Med in Ptch1(+/-) Trp53(-/-) mice with the antiestrogen chemotherapeutic drug Faslodex significantly increased symptom-free survival, which was associated with increased apoptosis and decreased BCL2 and IGF1R expression and signaling. Similar effects were also observed in nude mice bearing D283Med xenografts. In vitro studies in human D283Med cells metabolically stressed by glutamine withdrawal found that 17β-estradiol and the ERβ selective agonist 2,3-bis(4-hydroxyphenyl)-propionitrile dose dependently protected Med cells from caspase-3-dependent cell death. Those effects were associated with increased phosphorylation of IGF1R, long-term increases in ERK1/2 and AKT signaling, and increased expression of IGF-1, IGF1R, and BCL2. Results of pharmacological experiments revealed that the cytoprotective actions of estradiol were dependent on ERβ and IGF1R receptor tyrosine kinase activity and independent of ERα and G protein-coupled estrogen receptor 1 (G protein coupled receptor 30). The presented results demonstrate that estrogen promotes Med growth through ERβ-mediated increases in IGF1R expression and activity, which induce cytoprotective mechanisms that decrease apoptosis.
Collapse
MESH Headings
- Animals
- Apoptosis/drug effects
- Apoptosis/genetics
- Caspase 3/metabolism
- Cell Line, Tumor
- Estradiol/pharmacology
- Estrogen Receptor beta/genetics
- Estrogen Receptor beta/metabolism
- Female
- Gene Expression Regulation, Neoplastic/drug effects
- Gene Expression Regulation, Neoplastic/genetics
- Humans
- Insulin-Like Growth Factor I/drug effects
- Insulin-Like Growth Factor I/genetics
- Insulin-Like Growth Factor I/metabolism
- Insulin-Like Growth Factor II/drug effects
- Insulin-Like Growth Factor II/genetics
- Insulin-Like Growth Factor II/metabolism
- Male
- Medulloblastoma/genetics
- Medulloblastoma/metabolism
- Mice
- Mice, Knockout
- Patched Receptors
- Patched-1 Receptor
- Proto-Oncogene Proteins c-bcl-2/drug effects
- Proto-Oncogene Proteins c-bcl-2/metabolism
- RNA, Messenger/drug effects
- RNA, Messenger/metabolism
- Receptor, IGF Type 1/drug effects
- Receptor, IGF Type 1/genetics
- Receptor, IGF Type 1/metabolism
- Receptors, Cell Surface/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Tumor Suppressor Protein p53/genetics
- Up-Regulation/drug effects
- Up-Regulation/genetics
Collapse
Affiliation(s)
- Clifford J Cookman
- Department of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0575
| | - Scott M Belcher
- Department of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0575
| |
Collapse
|
7
|
Mayfield J, Blednov YA, Harris RA. Behavioral and Genetic Evidence for GIRK Channels in the CNS: Role in Physiology, Pathophysiology, and Drug Addiction. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2015; 123:279-313. [PMID: 26422988 DOI: 10.1016/bs.irn.2015.05.016] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
G protein-coupled inwardly rectifying potassium (GIRK) channels are widely expressed throughout the brain and mediate the inhibitory effects of many neurotransmitters. As a result, these channels are important for normal CNS function and have also been implicated in Down syndrome, Parkinson's disease, psychiatric disorders, epilepsy, and drug addiction. Knockout mouse models have provided extensive insight into the significance of GIRK channels under these conditions. This review examines the behavioral and genetic evidence from animal models and genetic association studies in humans linking GIRK channels with CNS disorders. We further explore the possibility that subunit-selective modulators and other advanced research tools will be instrumental in establishing the role of individual GIRK subunits in drug addiction and other relevant CNS diseases and in potentially advancing treatment options for these disorders.
Collapse
Affiliation(s)
- Jody Mayfield
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, Texas, USA.
| | - Yuri A Blednov
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, Texas, USA
| | - R Adron Harris
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, Texas, USA
| |
Collapse
|
8
|
Jinks RN, Puffenberger EG, Baple E, Harding B, Crino P, Fogo AB, Wenger O, Xin B, Koehler AE, McGlincy MH, Provencher MM, Smith JD, Tran L, Al Turki S, Chioza BA, Cross H, Harlalka GV, Hurles ME, Maroofian R, Heaps AD, Morton MC, Stempak L, Hildebrandt F, Sadowski CE, Zaritsky J, Campellone K, Morton DH, Wang H, Crosby A, Strauss KA. Recessive nephrocerebellar syndrome on the Galloway-Mowat syndrome spectrum is caused by homozygous protein-truncating mutations of WDR73. Brain 2015; 138:2173-90. [PMID: 26070982 PMCID: PMC4511861 DOI: 10.1093/brain/awv153] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 04/14/2015] [Indexed: 12/20/2022] Open
Abstract
Galloway-Mowat syndrome (GMS) is a neurodevelopmental disorder characterized by microcephaly, cerebellar hypoplasia, nephrosis, and profound intellectual disability. Jinks et al. extend the GMS spectrum by identifying a novel nephrocerebellar syndrome with selective striatal cholinergic interneuron loss and complete lateral geniculate nucleus delamination, caused by a frameshift mutation in WDR73. We describe a novel nephrocerebellar syndrome on the Galloway-Mowat syndrome spectrum among 30 children (ages 1.0 to 28 years) from diverse Amish demes. Children with nephrocerebellar syndrome had progressive microcephaly, visual impairment, stagnant psychomotor development, abnormal extrapyramidal movements and nephrosis. Fourteen died between ages 2.7 and 28 years, typically from renal failure. Post-mortem studies revealed (i) micrencephaly without polymicrogyria or heterotopia; (ii) atrophic cerebellar hemispheres with stunted folia, profound granule cell depletion, Bergmann gliosis, and signs of Purkinje cell deafferentation; (iii) selective striatal cholinergic interneuron loss; and (iv) optic atrophy with delamination of the lateral geniculate nuclei. Renal tissue showed focal and segmental glomerulosclerosis and extensive effacement and microvillus transformation of podocyte foot processes. Nephrocerebellar syndrome mapped to 700 kb on chromosome 15, which contained a single novel homozygous frameshift variant (WDR73 c.888delT; p.Phe296Leufs*26). WDR73 protein is expressed in human cerebral cortex, hippocampus, and cultured embryonic kidney cells. It is concentrated at mitotic microtubules and interacts with α-, β-, and γ-tubulin, heat shock proteins 70 and 90 (HSP-70; HSP-90), and the carbamoyl phosphate synthetase 2/aspartate transcarbamylase/dihydroorotase multi-enzyme complex. Recombinant WDR73 p.Phe296Leufs*26 and p.Arg256Profs*18 proteins are truncated, unstable, and show increased interaction with α- and β-tubulin and HSP-70/HSP-90. Fibroblasts from patients homozygous for WDR73 p.Phe296Leufs*26 proliferate poorly in primary culture and senesce early. Our data suggest that in humans, WDR73 interacts with mitotic microtubules to regulate cell cycle progression, proliferation and survival in brain and kidney. We extend the Galloway-Mowat syndrome spectrum with the first description of diencephalic and striatal neuropathology.
Collapse
Affiliation(s)
- Robert N Jinks
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA
| | - Erik G Puffenberger
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA 2 Clinic for Special Children, Strasburg, PA 17579, USA
| | - Emma Baple
- 3 RILD Wellcome Wolfson Centre, Royal Devon and Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK 4 Human Genetics and Genomic Medicine, Faculty of Medicine, University of Southampton, UK 5 Wessex Clinical Genetics Service, Princess Anne Hospital, Southampton, UK
| | - Brian Harding
- 6 Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia and Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Peter Crino
- 7 Shriners Hospital Paediatric Research Centre, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Agnes B Fogo
- 8 Division of Renal Pathology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Olivia Wenger
- 9 New Leaf Clinic for Special Children, Mount Eaton, OH 44659, USA 10 Department of Paediatrics, Akron Children's Hospital, Akron, OH 44302, USA
| | - Baozhong Xin
- 11 DDC Clinic for Special Needs Children, Middlefield, OH 44062, USA
| | - Alanna E Koehler
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA
| | - Madeleine H McGlincy
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA
| | - Margaret M Provencher
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA
| | - Jeffrey D Smith
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA
| | - Linh Tran
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA
| | - Saeed Al Turki
- 12 Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Barry A Chioza
- 13 Medical Research, RILD Wellcome Wolfson Centre, University of Exeter Medical School, Exeter EX1 2LU, UK
| | - Harold Cross
- 14 Department of Ophthalmology, University of Arizona College of Medicine, Tucson, AZ 85711, USA
| | - Gaurav V Harlalka
- 13 Medical Research, RILD Wellcome Wolfson Centre, University of Exeter Medical School, Exeter EX1 2LU, UK
| | - Matthew E Hurles
- 12 Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Reza Maroofian
- 13 Medical Research, RILD Wellcome Wolfson Centre, University of Exeter Medical School, Exeter EX1 2LU, UK
| | - Adam D Heaps
- 2 Clinic for Special Children, Strasburg, PA 17579, USA
| | - Mary C Morton
- 2 Clinic for Special Children, Strasburg, PA 17579, USA
| | - Lisa Stempak
- 15 Department of Pathology, University Hospitals Case Medical Centre, Cleveland, OH 44106, USA 16 Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Friedhelm Hildebrandt
- 17 Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA 18 Division of Nephrology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Carolin E Sadowski
- 18 Division of Nephrology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Joshua Zaritsky
- 19 Department of Paediatrics, Nemours/Alfred I. DuPont Hospital for Children, Wilmington, DE 19803, USA
| | - Kenneth Campellone
- 20 Department of Molecular and Cell Biology and Institute for Systems Genomics, University of Connecticut, Storrs, CT 06269, USA
| | - D Holmes Morton
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA 2 Clinic for Special Children, Strasburg, PA 17579, USA 21 Lancaster General Hospital, Lancaster, PA 17602, USA
| | - Heng Wang
- 11 DDC Clinic for Special Needs Children, Middlefield, OH 44062, USA 22 Department of Paediatrics, Rainbow Babies and Children's Hospital and Department of Molecular Cardiology, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Andrew Crosby
- 3 RILD Wellcome Wolfson Centre, Royal Devon and Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK
| | - Kevin A Strauss
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA 2 Clinic for Special Children, Strasburg, PA 17579, USA 21 Lancaster General Hospital, Lancaster, PA 17602, USA
| |
Collapse
|
9
|
Shevelkin AV, Ihenatu C, Pletnikov MV. Pre-clinical models of neurodevelopmental disorders: focus on the cerebellum. Rev Neurosci 2014; 25:177-94. [PMID: 24523305 PMCID: PMC4052755 DOI: 10.1515/revneuro-2013-0049] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 12/31/2013] [Indexed: 12/24/2022]
Abstract
Recent studies have advanced our understanding of the role of the cerebellum in non-motor behaviors. Abnormalities in the cerebellar structure have been demonstrated to produce changes in emotional, cognitive, and social behaviors resembling clinical manifestations observed in patients with autism spectrum disorders (ASD) and schizophrenia. Several animal models have been used to evaluate the effects of relevant environmental and genetic risk factors on the cerebellum development and function. However, very few models of ASD and schizophrenia selectively target the cerebellum and/or specific cell types within this structure. In this review, we critically evaluate the strength and weaknesses of these models. We will propose that the future progress in this field will require time- and cell type-specific manipulations of disease-relevant genes, not only selectively in the cerebellum, but also in frontal brain areas connected with the cerebellum. Such information can advance our knowledge of the cerebellar contribution to non-motor behaviors in mental health and disease.
Collapse
|
10
|
Martí J, Santa-Cruz MC, Serra R, Valero O, Molina V, Hervás JP, Villegas S. Principal component and cluster analysis of morphological variables reveals multiple discrete sub-phenotypes in weaver mouse mutants. THE CEREBELLUM 2013. [PMID: 23179325 DOI: 10.1007/s12311-012-0429-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The present study evaluates the usefulness of the principal component analysis-based cluster analysis in the categorization of several sub-phenotypes in the weaver mutant by using several morphological parameters from the cerebellar cortex of control, heterozygous (+/wv) and homozygous (wv/wv) weaver mice. The quantified parameters were length of the cerebellar cortex, area of the external granular layer, area of the molecular layer, number of the external granular layer cells (EGL), and number of Purkinje cells (PCs). The analysis indicated that at postnatal day 8, the genotype +/wv presented three sub-phenotypes tagged as +/wv (0), +/wv (1) and +/wv (2), whereas two sub-phenotypes designated as wv (0)/wv (1) and wv (0)/wv (2) were identified in the genotype wv/wv. The number of PCs for the genotype +/wv and the number of EGL cells for the genotype wv/wv were the variables that discriminated the best among sub-phenotypes. Each one of the sub-phenotypes showed specific abnormalities in the cytoarchitecture of the cerebellar cortex as well as in the foliar pattern. In particular, the wv (0)/wv (1) and wv (0)/wv (2) sub-phenotypes had the most altered cytoarchitectonics, followed by the +/wv (2) sub-phenotype and then by the +/wv (1) one. The sub-phenotype +/wv (0) was the less affected one. Apart from reporting for the first time the coexistence of several sub-phenotypes in the weaver mutant, our approach provides a new statistical tool that can be used to assess cerebellar morphology.
Collapse
Affiliation(s)
- Joaquín Martí
- Departament de Biologia Cel.lular, de Fisiologia i d'Immunologia. Unidad de Citologia i d'Histologia. Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.
| | | | | | | | | | | | | |
Collapse
|
11
|
Kielar C, Sawiak SJ, Navarro Negredo P, Tse DHY, Morton AJ. Tensor-based morphometry and stereology reveal brain pathology in the complexin1 knockout mouse. PLoS One 2012; 7:e32636. [PMID: 22393426 PMCID: PMC3290572 DOI: 10.1371/journal.pone.0032636] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 01/28/2012] [Indexed: 11/18/2022] Open
Abstract
Complexins (Cplxs) are small, soluble, regulatory proteins that bind reversibly to the SNARE complex and modulate synaptic vesicle release. Cplx1 knockout mice (Cplx1(-/-)) have the earliest known onset of ataxia seen in a mouse model, although hitherto no histopathology has been described in these mice. Nevertheless, the profound neurological phenotype displayed by Cplx1(-/-) mutants suggests that significant functional abnormalities must be present in these animals. In this study, MRI was used to automatically detect regions where structural differences were not obvious when using a traditional histological approach. Tensor-based morphometry of Cplx1(-/-) mouse brains showed selective volume loss from the thalamus and cerebellum. Stereological analysis of Cplx1(-/-) and Cplx1(+/+) mice brain slices confirmed the volume loss in the thalamus as well as loss in some lobules of the cerebellum. Finally, stereology was used to show that there was loss of cerebellar granule cells in Cplx1(-/-) mice when compared to Cplx1(+/+) animals. Our study is the first to describe pathological changes in Cplx1(-/-) mouse brain. We suggest that the ataxia in Cplx1(-/-) mice is likely to be due to pathological changes in both cerebellum and thalamus. Reduced levels of Cplx proteins have been reported in brains of patients with neurodegenerative diseases. Therefore, understanding the effects of Cplx depletion in brains from Cplx1(-/-) mice may also shed light on the mechanisms underlying pathophysiology in disorders in which loss of Cplx1 occurs.
Collapse
Affiliation(s)
- Catherine Kielar
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| | - Stephen J. Sawiak
- Wolfson Brain Imaging Centre, Addenbrooke's Hospital, Cambridge, United Kingdom
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom
| | | | - Desmond H. Y. Tse
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| | - A. Jennifer Morton
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| |
Collapse
|
12
|
Chang YC, Lin CY, Hsu CM, Lin HC, Chen YH, Lee-Chen GJ, Su MT, Ro LS, Chen CM, Hsieh-Li HM. Neuroprotective effects of granulocyte-colony stimulating factor in a novel transgenic mouse model of SCA17. J Neurochem 2011; 118:288-303. [PMID: 21554323 DOI: 10.1111/j.1471-4159.2011.07304.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Spinocerebellar ataxia type 17 (SCA17) is an autosomal dominant inherited disorder characterized by degeneration of spinocerebellar tracts and selected brainstem neurons owing to the expansion of a CAG repeat of the human TATA-binding protein (hTBP) gene. To gain insight into the pathogenesis of this hTBP mutation, we generated transgenic mice with the mutant hTBP gene driven by the Purkinje specific protein (Pcp2/L7) gene promoter. Mice with the expanded hTBP allele developed ataxia within 2-5 months. Behavioral analysis of L7-hTBP transgenic mice showed reduced fall latency in a rotarod assay. Purkinje cell degeneration was identified by immunostaining of calbindin and IP3R1. Reactive gliosis and neuroinflammation occurred in the transgenic cerebellum, accompanied by up-regulation of GFAP and Iba1. The L7-hTBP transgenic mice were thus confirmed to recapitulate the SCA17 phenotype and were used as a disease model to explore the potential of granulocyte-colony stimulating factor in SCA17 treatment. Our results suggest that granulocyte-colony stimulating factor has a neuroprotective effect in these transgenic mice, ameliorating their neurological and behavioral deficits. These data indicate that the expression of the mutant hTBP in Purkinje cells is sufficient to produce cell degeneration and an ataxia phenotype, and constitutes a good model for better analysis of the neurodegeneration in SCA17.
Collapse
Affiliation(s)
- Ya-Chin Chang
- Department of Life Science, National Taiwan Normal University, Taipei, Taiwan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Emerging roles for G protein-gated inwardly rectifying potassium (GIRK) channels in health and disease. Nat Rev Neurosci 2010; 11:301-15. [PMID: 20389305 DOI: 10.1038/nrn2834] [Citation(s) in RCA: 451] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
G protein-gated inwardly rectifying potassium (GIRK) channels hyperpolarize neurons in response to activation of many different G protein-coupled receptors and thus control the excitability of neurons through GIRK-mediated self-inhibition, slow synaptic potentials and volume transmission. GIRK channel function and trafficking are highly dependent on the channel subunit composition. Pharmacological investigations of GIRK channels and studies in animal models suggest that GIRK activity has an important role in physiological responses, including pain perception and memory modulation. Moreover, abnormal GIRK function has been implicated in altering neuronal excitability and cell death, which may be important in the pathophysiology of diseases such as epilepsy, Down's syndrome, Parkinson's disease and drug addiction. GIRK channels may therefore prove to be a valuable new therapeutic target.
Collapse
|
14
|
Lathrop MJ, Chakrabarti L, Eng J, Rhodes CH, Lutz T, Nieto A, Liggitt HD, Warner S, Fields J, Stöger R, Fiering S. Deletion of the Chd6 exon 12 affects motor coordination. Mamm Genome 2010; 21:130-42. [PMID: 20111866 PMCID: PMC2844962 DOI: 10.1007/s00335-010-9248-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Accepted: 12/08/2009] [Indexed: 01/03/2023]
Abstract
Members of the CHD protein family play key roles in gene regulation through ATP-dependent chromatin remodeling. This is facilitated by chromodomains that bind histone tails, and by the SWI2/SNF2-like ATPase/helicase domain that remodels chromatin by moving histones. Chd6 is ubiquitously expressed in both mouse and human, with the highest levels of expression in the brain. The Chd6 gene contains 37 exons, of which exons 12-19 encode the highly conserved ATPase domain. To determine the biological role of Chd6, we generated mouse lines with a deletion of exon 12. Chd6 without exon 12 is expressed at normal levels in mice, and Chd6 Exon 12 −/− mice are viable, fertile, and exhibit no obvious morphological or pathological phenotype. Chd6 Exon 12 −/− mice lack coordination as revealed by sensorimotor analysis. Further behavioral testing revealed that the coordination impairment was not due to muscle weakness or bradykinesia. Histological analysis of brain morphology revealed no differences between Chd6 Exon 12 −/− mice and wild-type (WT) controls. The location of CHD6 on human chromosome 20q12 is overlapped by the linkage map regions of several human ataxias, including autosomal recessive infantile cerebellar ataxia (SCAR6), a nonprogressive cerebrospinal ataxia. The genomic location, expression pattern, and ataxic phenotype of Chd6 Exon 12 −/− mice indicate that mutations within CHD6 may be responsible for one of these ataxias.
Collapse
Affiliation(s)
- Melissa J Lathrop
- Department of Microbiology/Immunology, and Norris Cotton Cancer Center, Dartmouth Medical School, Hanover, NH 03755, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Laffaire J, Rivals I, Dauphinot L, Pasteau F, Wehrle R, Larrat B, Vitalis T, Moldrich RX, Rossier J, Sinkus R, Herault Y, Dusart I, Potier MC. Gene expression signature of cerebellar hypoplasia in a mouse model of Down syndrome during postnatal development. BMC Genomics 2009; 10:138. [PMID: 19331679 PMCID: PMC2678156 DOI: 10.1186/1471-2164-10-138] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Accepted: 03/30/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Down syndrome is a chromosomal disorder caused by the presence of three copies of chromosome 21. The mechanisms by which this aneuploidy produces the complex and variable phenotype observed in people with Down syndrome are still under discussion. Recent studies have demonstrated an increased transcript level of the three-copy genes with some dosage compensation or amplification for a subset of them. The impact of this gene dosage effect on the whole transcriptome is still debated and longitudinal studies assessing the variability among samples, tissues and developmental stages are needed. RESULTS We thus designed a large scale gene expression study in mice (the Ts1Cje Down syndrome mouse model) in which we could measure the effects of trisomy 21 on a large number of samples (74 in total) in a tissue that is affected in Down syndrome (the cerebellum) and where we could quantify the defect during postnatal development in order to correlate gene expression changes to the phenotype observed. Statistical analysis of microarray data revealed a major gene dosage effect: for the three-copy genes as well as for a 2 Mb segment from mouse chromosome 12 that we show for the first time as being deleted in the Ts1Cje mice. This gene dosage effect impacts moderately on the expression of euploid genes (2.4 to 7.5% differentially expressed). Only 13 genes were significantly dysregulated in Ts1Cje mice at all four postnatal development stages studied from birth to 10 days after birth, and among them are 6 three-copy genes. The decrease in granule cell proliferation demonstrated in newborn Ts1Cje cerebellum was correlated with a major gene dosage effect on the transcriptome in dissected cerebellar external granule cell layer. CONCLUSION High throughput gene expression analysis in the cerebellum of a large number of samples of Ts1Cje and euploid mice has revealed a prevailing gene dosage effect on triplicated genes. Moreover using an enriched cell population that is thought responsible for the cerebellar hypoplasia in Down syndrome, a global destabilization of gene expression was not detected. Altogether these results strongly suggest that the three-copy genes are directly responsible for the phenotype present in cerebellum. We provide here a short list of candidate genes.
Collapse
Affiliation(s)
- Julien Laffaire
- Laboratoire de Neurobiologie, CNRS UMR7637, ESPCI, Paris, France
- CRICM, CNRS UMR7225, INSERM UMR975, UPMC, CHU Pitie-Salpetriere, Paris, France
| | | | - Luce Dauphinot
- Laboratoire de Neurobiologie, CNRS UMR7637, ESPCI, Paris, France
- CRICM, CNRS UMR7225, INSERM UMR975, UPMC, CHU Pitie-Salpetriere, Paris, France
| | - Fabien Pasteau
- Laboratoire de Neurobiologie, CNRS UMR7637, ESPCI, Paris, France
| | - Rosine Wehrle
- Neurobiologie des Processus Adaptatifs, CNRS UMR7102, Paris, France
- UPMC, Paris, France
| | - Benoit Larrat
- Laboratoire Ondes et Accoustique, UMR7587, ESPCI, Paris, France
| | - Tania Vitalis
- Laboratoire de Neurobiologie, CNRS UMR7637, ESPCI, Paris, France
| | - Randal X Moldrich
- Laboratoire de Neurobiologie, CNRS UMR7637, ESPCI, Paris, France
- The Queensland Brain Institute, St Lucia, Australia
| | - Jean Rossier
- Laboratoire de Neurobiologie, CNRS UMR7637, ESPCI, Paris, France
| | - Ralph Sinkus
- Laboratoire Ondes et Accoustique, UMR7587, ESPCI, Paris, France
| | | | - Isabelle Dusart
- Neurobiologie des Processus Adaptatifs, CNRS UMR7102, Paris, France
- UPMC, Paris, France
| | - Marie-Claude Potier
- Laboratoire de Neurobiologie, CNRS UMR7637, ESPCI, Paris, France
- CRICM, CNRS UMR7225, INSERM UMR975, UPMC, CHU Pitie-Salpetriere, Paris, France
| |
Collapse
|
16
|
Káradóttir R, Attwell D. Neurotransmitter receptors in the life and death of oligodendrocytes. Neuroscience 2006; 145:1426-38. [PMID: 17049173 PMCID: PMC2173944 DOI: 10.1016/j.neuroscience.2006.08.070] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2006] [Revised: 07/20/2006] [Accepted: 08/18/2006] [Indexed: 10/25/2022]
Abstract
Oligodendrocytes are crucial to the function of the mammalian brain: they increase the action potential conduction speed for a given axon diameter and thus facilitate the rapid flow of information between different brain areas. The proliferation and differentiation of developing oligodendrocytes, and their myelination of axons, are partly controlled by neurotransmitters. In addition, in models of conditions like stroke, periventricular leukomalacia leading to cerebral palsy, spinal cord injury and multiple sclerosis, oligodendrocytes are damaged by glutamate and, contrary to dogma, it has recently been discovered that this damage is mediated in part by N-methyl-D-aspartate receptors. Mutations in oligodendrocyte neurotransmitter receptors or their interacting proteins may cause defects in CNS function. Here we review the roles of neurotransmitter receptors in the normal function, and malfunction in pathological conditions, of oligodendrocytes.
Collapse
Affiliation(s)
- R Káradóttir
- Department of Physiology, University College London, Gower Street, London WC1E 6BT, UK.
| | | |
Collapse
|
17
|
Sgadò P, Albéri L, Gherbassi D, Galasso SL, Ramakers GMJ, Alavian KN, Smidt MP, Dyck RH, Simon HH. Slow progressive degeneration of nigral dopaminergic neurons in postnatal Engrailed mutant mice. Proc Natl Acad Sci U S A 2006; 103:15242-7. [PMID: 17015829 PMCID: PMC1622807 DOI: 10.1073/pnas.0602116103] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The homeobox transcription factors Engrailed-1 and Engrailed-2 are required for the survival of mesencephalic dopaminergic neurons in a cell-autonomous and gene-dose-dependent manner. Because of this requirement, the cells die by apoptosis when all four alleles of the Engrailed genes are genetically ablated (En1-/-;En2-/-). In the present study, we show that viable and fertile mice, heterozygous null for Engrailed-1 and homozygous null for Engrailed-2 (En1+/-;En2-/-), have an adult phenotype that resembles key pathological features of Parkinson's disease. Specifically, postnatal mutant mice exhibit a progressive degeneration of dopaminergic neurons in the substantia nigra during the first 3 mo of their lives, leading to diminished storage and release of dopamine in the caudate putamen, motor deficits similar to akinesia and bradykinesia, and a lower body weight. This genetic model may provide access to the molecular etiology for Parkinson's disease and could assist in the development of novel treatments for this neurodegenerative disorder.
Collapse
Affiliation(s)
- Paola Sgadò
- *Interdisciplinary Center for Neuroscience, Department of Neuroanatomy, Ruprecht-Karls Universität Heidelberg, 69120 Heidelberg, Germany
| | - Lavinia Albéri
- *Interdisciplinary Center for Neuroscience, Department of Neuroanatomy, Ruprecht-Karls Universität Heidelberg, 69120 Heidelberg, Germany
| | - Daniel Gherbassi
- *Interdisciplinary Center for Neuroscience, Department of Neuroanatomy, Ruprecht-Karls Universität Heidelberg, 69120 Heidelberg, Germany
| | - Sherri L. Galasso
- Departments of Psychology and Cell Biology and Anatomy, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada T2N 1N4
| | - Geert M. J. Ramakers
- Rudolf Magnus Institute of Neuroscience, Department of Pharmacology and Anatomy, University Medical Centre, 3584 CG Utrecht, The Netherlands; and
| | - Kambiz N. Alavian
- *Interdisciplinary Center for Neuroscience, Department of Neuroanatomy, Ruprecht-Karls Universität Heidelberg, 69120 Heidelberg, Germany
| | - Marten P. Smidt
- Rudolf Magnus Institute of Neuroscience, Department of Pharmacology and Anatomy, University Medical Centre, 3584 CG Utrecht, The Netherlands; and
| | - Richard H. Dyck
- Departments of Psychology and Cell Biology and Anatomy, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada T2N 1N4
| | - Horst H. Simon
- *Interdisciplinary Center for Neuroscience, Department of Neuroanatomy, Ruprecht-Karls Universität Heidelberg, 69120 Heidelberg, Germany
- To whom correspondence should be addressed. E-mail:
| |
Collapse
|
18
|
Harashima C, Jacobowitz DM, Stoffel M, Chakrabarti L, Haydar TF, Siarey RJ, Galdzicki Z. Elevated expression of the G-protein-activated inwardly rectifying potassium channel 2 (GIRK2) in cerebellar unipolar brush cells of a Down syndrome mouse model. Cell Mol Neurobiol 2006; 26:719-34. [PMID: 16783527 DOI: 10.1007/s10571-006-9066-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2005] [Accepted: 03/22/2006] [Indexed: 10/24/2022]
Abstract
1. Down syndrome (DS) arises from the presence of three copies of chromosome (Chr.) 21. Fine motor learning deficits found in DS from childhood to adulthood result from expression of extra genes on Chr. 21, however, it remains unclear which if any of these genes are the specific causes of the cognitive and motor dysfunction. DS cerebellum displays morphological abnormalities that likely contribute to the DS motor phenotype. 2. The G-protein-activated inwardly rectifying potassium channel subunit 2 (GIRK2) is expressed in cerebellum and can shunt dendritic conductance and attenuate postsynaptic potentials. We have used an interbreeding approach to cross a genetic mouse model of DS (Ts65Dn) with Girk2 knockout mice and examined its relative expression level by quantitative real-time RT-PCR, Western blotting and immunohistochemistry. 3. We report here for the first time that GIRK2 is expressed in unipolar brush cells, which are excitatory interneurons of the vestibulocerebellum and dorsal cochlear nucleus. Analysis of disomic-Ts65Dn/Girk2((+/+/-)) and heterozygous-Diploid/Girk2((+/-)) mice shows that GIRK2 expression in Ts65Dn lobule X follows gene dosage. The lobule X of Ts65Dn mice contain greater numbers of unipolar brush cells co-expressing GIRK2 and calretinin than the control mouse groups. 4. These results demonstrate that gene triplication can impact specific cell types in the cerebellum. We hypothesize that GIRK2 overexpression will adversely affect cerebellar circuitry in Ts65Dn vestibulocerebellum and dorsal cochlear nucleus due to GIRK2 shunting properties and its effects on resting membrane potential.
Collapse
Affiliation(s)
- Chie Harashima
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, School of Medicine, Bethesda, Maryland 20814, USA
| | | | | | | | | | | | | |
Collapse
|
19
|
Sharma SK, Ebadi M. Distribution kinetics of 18F-DOPA in weaver mutant mice. ACTA ACUST UNITED AC 2005; 139:23-30. [PMID: 15979197 DOI: 10.1016/j.molbrainres.2005.05.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2005] [Revised: 04/25/2005] [Accepted: 05/03/2005] [Indexed: 11/19/2022]
Abstract
Distribution kinetics of 18F-fluoro-dihydroxy phenylalanine (18F-DOPA) were studied with high-resolution micro-positron emission tomography (microPET) imaging and conventional methods in control wild-type mice, heterozygous weaver mutant mice, and homozygous weaver mutant mice. 18F-DOPA uptake was significantly increased in the CNS within 60 min in all the genotypes examined. Homozygous weaver mutant mice exhibited significantly reduced 18F-DOPA uptake in the region of interest (striatum) as compared to heterozygous weaver mutant mice and control wild-type mice. 18F-DOPA was de-localized in the kidneys of homozygous weaver mutant mice. The radioactivity was localized primarily in the liver and kidneys within 2 h and in the urinary bladder within 4 h. After 8 h, it could be detected neither by conventional nor by microPET imaging. Distribution kinetics of 18F-DOPA with microPET imaging correlated and confirmed the conventional observations. These data are interpreted to suggest that microPET imaging may provide an efficient, noninvasive, cost-effective procedure to study distribution kinetics of PET radiopharmaceuticals in rare genetically altered animals. Furthermore, this unique and noninvasive approach may expedite quality control and drug development for human applications.
Collapse
Affiliation(s)
- Sushil K Sharma
- Center of Excellence in Neuroscience, University of North Dakota School of Medicine and Health Sciences, 501 North Columbia Road, Grand Forks, ND 58203, USA
| | | |
Collapse
|