Journal Mobile Options
Table of Contents
Vol. 28, No. 3, 2006
Issue release date: May 2006
Dev Neurosci 2006;28:230–238
(DOI:10.1159/000091921)

Changes in Expression of N-Methyl-D-Aspartate Receptor Subunits Occur Early in the R6/2 Mouse Model of Huntington’s Disease

Ali N.J. · Levine M.S.
Mental Retardation Research Center, The David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, Calif., USA
email Corresponding Author

Abstract

A leading hypothesis of the cause of neuronal death in Huntington’s disease (HD) is excitotoxicity, in which subpopulations of striatal neurons are hypersensitive to glutamate release due to changes in postsynaptic N-methyl-D-aspartate receptors (NMDARs). In the present study we used RT-PCR methods on single cells and tissue to compare the expression of NMDAR subunits, NR1, NR2A and NR2B, in the striatum of R6/2 transgenic mice with their wild-type (WT) littermates at three different age groups corresponding to different symptomatic milestones (19–25 days showing no overt evidence of abnormal behavior, 38–45 days at the onset of the overt phenotype and 78–90 days displaying the full behavioral phenotype). Single-cell RT-PCR studies also examined neurons for the expression of substance P and enkephalin to define different subpopulations of medium-sized projection neurons of the striatum. The results showed a significant decrease in the percentage of cells expressing NR2A at all ages examined. The decrease in expression was not associated with any significant change in expression of NR1 or NR2B. Cells that did not express NR2A contained both enkephalin and substance P, but proportionately more cells containing enkephalin displayed decreases in NR2A. Semi-quantitative RT-PCR studies on striatal tissue in the oldest age group confirmed the significant decrease in NR2A and also showed a decrease in NR2B. These results support the hypothesis that changes in the composition of postsynaptic NMDARs occur in the R6/2 model of HD and this effect occurs early in the expression of the phenotype.


 goto top of outline Key Words

  • Huntington’s disease
  • R6/2 mouse model
  • N-methyl-D-aspartate receptors
  • Receptor subunit RNA
  • Single-cell RT-PCR

 goto top of outline Abstract

A leading hypothesis of the cause of neuronal death in Huntington’s disease (HD) is excitotoxicity, in which subpopulations of striatal neurons are hypersensitive to glutamate release due to changes in postsynaptic N-methyl-D-aspartate receptors (NMDARs). In the present study we used RT-PCR methods on single cells and tissue to compare the expression of NMDAR subunits, NR1, NR2A and NR2B, in the striatum of R6/2 transgenic mice with their wild-type (WT) littermates at three different age groups corresponding to different symptomatic milestones (19–25 days showing no overt evidence of abnormal behavior, 38–45 days at the onset of the overt phenotype and 78–90 days displaying the full behavioral phenotype). Single-cell RT-PCR studies also examined neurons for the expression of substance P and enkephalin to define different subpopulations of medium-sized projection neurons of the striatum. The results showed a significant decrease in the percentage of cells expressing NR2A at all ages examined. The decrease in expression was not associated with any significant change in expression of NR1 or NR2B. Cells that did not express NR2A contained both enkephalin and substance P, but proportionately more cells containing enkephalin displayed decreases in NR2A. Semi-quantitative RT-PCR studies on striatal tissue in the oldest age group confirmed the significant decrease in NR2A and also showed a decrease in NR2B. These results support the hypothesis that changes in the composition of postsynaptic NMDARs occur in the R6/2 model of HD and this effect occurs early in the expression of the phenotype.

Copyright © 2006 S. Karger AG, Basel


 goto top of outline References
  1. Albin RL, Young AB, Penney JB (1989): The functional anatomy of basal ganglia disorders. Trends Neurosci 12:366–375.
  2. Ariano MA, Wagle N, Grissell AE (2005): Neuronal vulnerability in mouse models of Huntington’s disease: membrane channel protein changes. J Neurosci Res 80:634–645.
  3. Beal MF, Hyman BT, Koroshetz W (1993): Do defects in mitochondrial energy metabolism underlie the pathology of neurodegenerative diseases? Trends Neurosci 16:125–131.
  4. Behe P, Stern P, Wyllie DJ, Nassar M, Schoepfer R, Colquhoun D (1995): Determination of NMDA NR1 subunit copy number in recombinant NMDA receptors. Proc R Soc Lond B Biol Sci 262:205–213.
  5. Bibb JA, Yan Z, Svenningsson P, Snyder GL, Pieribone VA, Horiuchi A, Nairn AC, Messer A, Greengard P (2000): Severe deficiencies in dopamine signaling in presymptomatic Huntington’s disease mice. Proc Natl Acad Sci USA 97:6809–6814.
  6. Bonfoco E, Krainc D, Ankarcrona M, Nicotera P, Lipton SA (1995): Apoptosis and necrosis: two distinct events induced, respectively, by mild and intense insults with N-methyl-D-aspartate or nitric oxide/superoxide in cortical cell cultures. Proc Natl Acad Sci USA 92:7162–7166.
  7. Bordelon YM, Chesselet MF (1999): Early effects of intrastriatal injections of quinolinic acid on microtubule-associated protein-2 and neuropeptides in rat basal ganglia. Neuroscience 93:843–853.
  8. Carter RJ, Lione LA, Humby T, Mangiarini L, Mahal A, Bates GP, Dunnett SB, Morton AJ (1999): Characterization of progressive motor deficits in mice transgenic for the human Huntington’s disease mutation. J Neurosci 19:3248–3257.
  9. Cepeda C, Ariano MA, Calvert CR, Flores-Hernandez J, Chandler SH, Leavitt BR, Hayden MR, Levine MS (2001a): NMDA receptor function in mouse models of Huntington disease. J Neurosci Res 66:525–539.
  10. Cepeda C, Hurst RS, Calvert CR, Hernandez-Echeagaray E, Nguyen OK, Jocoy E, Christian LJ, Ariano MA, Levine MS (2003): Transient and progressive electrophysiological alterations in the corticostriatal pathway in a mouse model of Huntington’s disease. J Neurosci 23:961–969.
  11. Cepeda C, Itri JN, Flores-Hernandez J, Hurst RS, Calvert CR, Levine MS (2001b): Differential sensitivity of medium- and large-sized striatal neurons to NMDA but not kainate receptor activation in the rat. Eur J Neurosci 14:1577–1589.
  12. Cha JH, Frey AS, Alsdorf SA, Kerner JA., Kosinski CM, Mangiarini L, Penney JB Jr, Davies SW, Bates GP, Young AB (1999): Altered neurotransmitter receptor expression in transgenic mouse models of Huntington’s disease. Philos Trans R Soc Lond B Biol Sci 354:981–989.
  13. Cha JH, Kosinski CM, Kerner JA, Alsdorf SA, Mangiarini L, Davies SW, Penney JB, Bates GP, Young AB (1998): Altered brain neurotransmitter receptors in transgenic mice expressing a portion of an abnormal human Huntington disease gene. Proc Natl Acad Sci USA 95:6480–6485.
  14. Chapman DE, Keefe KA, Wilcox KS (2003): Evidence for functionally distinct synaptic NMDA receptors in ventromedial versus dorsolateral striatum. J Neurophysiol 89:69–80.
  15. Coyle JT (1979): An animal model for Huntington’s disease. Biol Psychiatry 14:251–276.
  16. Davies SW, Turmaine M, Cozens BA, DiFiglia M, Sharp AH, Ross CA, Scherzinger E, Wanker EE, Mangiarini L, Bates GP (1997): Formation of neuronal intranuclear inclusions underlies the neurological dysfunction in mice transgenic for the HD mutation. Cell 90:537–548.
  17. Davies SW, Turmaine, M, Cozens BA, Raza AS, Mahal A, Mangiarini L, Bates GP (1999): From neuronal inclusions to neurodegeneration: neuropathological investigation of a transgenic mouse model of Huntington’s disease. Philos Trans R Soc Lond B Biol Sci 354:981–989.
  18. DiFiglia M (1990): Excitotoxic injury of the neostriatum: a model for Huntington’s disease. Trends Neurosci 13:286–289.
  19. Dunah AW, Jeong H, Griffin A, Kim YM, Standaert DG, Hersch SM, Mouradian MM, Young AB, Tanese N, Krainc D (2002): Sp1 and TAFII130 transcriptional activity disrupted in early Huntington’s disease. Science 296:2238–2243.
  20. Ferrante RJ, Andreassen OA, Jenkins BG, Dedeoglu A, Kuemmerle S, Kubilus JK, Kaddurah-Daouk R, Hersch SM, Beal MF (2000): Neuroprotective effects of creatine in a transgenic mouse model of Huntington’s disease. J Neurosci 20:4389–4397.
  21. Hollmann M, Boulter J, Maron C, Heinemann S (1994): Molecular biology of glutamate receptors. Potentiation of N-methyl-D-aspartate receptor splice variants by zinc. Ren Physiol Biochem 17:182–183.
  22. Klapstein GJ, Fisher RS, Zanjani H, Cepeda C, Jokel ES, Chesselet MF, Levine MS (2001): Electrophysiological and morphological changes in striatal spiny neurons in R6/2 Huntington’s disease transgenic mice. J Neurophysiol 86:2667–2677.
  23. Kumar SS, Huguenard JR (2003): Pathway-specific differences in subunit composition of synaptic NMDA receptors on pyramidal neurons in neocortex. J Neurosci 31:10074–10083.

    External Resources

  24. Laforet GA, Sapp E, Chase K, McIntyre C, Boyce FM, Campbell M, Cadigan BA, Warzecki L, Tagle DA, Reddy PH, Cepeda C, Calvert CR, Jokel ES, Klapstein GJ, Ariano MA, Levine MS, DiFiglia M, Aronin N (2001): Changes in cortical and striatal neurons predict behavioral and electrophysiological abnormalities in a transgenic murine model of Huntington’s disease. J Neurosci 21:9112–9123.
  25. Levine MS, Klapstein GJ, Koppel A, Gruen E, Cepeda C, Vargas ME, Jokel ES, Carpenter EM, Zanjani H, Hurst RS, Efstratiadis A, Zeitlin S, Chesselet MF (1999): Enhanced sensitivity to N-methyl-D-aspartate receptor activation in transgenic and knockin mouse models of Huntington’s disease. J Neurosci Res 58:515–532.
  26. Li H, Li SH, Johnston H, Shelbourne PF, Li XJ (2000): Amino-terminal fragments of mutant huntingtin show selective accumulation in striatal neurons and synaptic toxicity. Nat Genet 25:385–389.
  27. Li L, Fan M, Icton CD, Chen N, Leavitt BR, Hayden MR, Murphy TH, Raymond LA (2003): Role of NR2B-type NMDA receptors in selective neurodegeneration in Huntington disease. Neurobiol Aging 24:1113–1121.
  28. Lione LA, Carter RJ, Hunt MJ, Bates GP, Morton AJ, Dunnett SB (1999): Selective discrimination learning impairments in mice expressing the human Huntington’s disease mutation. J Neurosci 19:10428–10437.
  29. Luthi-Carter R, Apostol BL, Dunah AW, DeJohn MM, Farrell LA, Bates GP, Young AB, Standaert DG, Thompson LM, Cha JH (2003): Complex alteration of NMDA receptors in transgenic Huntington’s disease mouse brain: analysis of mRNA and protein expression, plasma membrane association, interacting proteins, and phosphorylation. Neurobiol Dis 14:624–636.
  30. Luthi-Carter R, Strand A, Peters NL, Solano SM, Hollingsworth ZR, Menon AS, Frey AS, Spektor BS., Penney EB, Schilling G, Ross CA, Borchelt DR, Tapscott SJ, Young AB, Cha JH, Olson JM (2000): Decreased expression of striatal signaling genes in a mouse model of Huntington’s disease. Hum Mol Genet 9:1259–1271.
  31. Martin JB, Gusella JF (1986): Huntington’s disease. Pathogenesis and management. N Engl J Med 315:267–1276.
  32. Menalled L, Zanjani H, MacKenzie L, Koppel A, Carpenter E, Zeitlin S, Chesselet MF (2000): Decrease in striatal enkephalin mRNA in mouse models of Huntington’s disease. Exp Neurol 162:328–342.
  33. Murphy KP, Carter RJ, Lione LA, Mangiarini L, Mahal A, Bates GP, Dunnett SB, Morton AJ (2000): Abnormal synaptic plasticity and impaired spatial cognition in mice transgenic for exon 1 of the human Huntington’s disease mutation. J Neurosci 20:5115–5123.
  34. Qian A, Buller AL, Johnson JW (2005): NR2 subunit-dependence of NMDA receptor channel block by external Mg2+. J Physiol 562:319–331.
  35. Sathasivam K, Hobbs C, Mangiarini L, Mahal A, Turmaine M, Doherty P, Davies SW, Bates GP (1999): Transgenic models of Huntington’s disease. Philos Trans R Soc Lond B Biol Sci 354:963–969.
  36. Schwarcz R, Foster AC, French ED, Whetsell WO Jr, Kohler C (1984): Excitotoxic models for neurodegenerative disorders. Life Sci 35:19–32.
  37. Starling AJ, Cepeda C, de Lima M, Chandler SH, Levine MS (2005): Alterations in N-methyl-D-aspartate receptor sensitivity and magnesium blockade occur early in development in the R6/2 mouse model of Huntington’s disease. J Neurosci Res 82:377–386.
  38. Vonsattel JP, DiFiglia M (1998): Huntington disease. J Neuropathol Exp Neurol 57:369–384.
  39. Vonsattel JP, Myers RH, Stevens TJ, Ferrante RJ, Bird ED, Richardson EP Jr (1985): Neuropathological classification of Huntington’s disease. J Neuropathol Exp Neurol 44:559–577.
  40. Zeron MM, Chen N, Moshaver A, Lee AT, Wellington CL, Hayden MR, Raymond LA (2001): Mutant huntingtin enhances excitotoxic cell death. Mol Cell Neurosci 17:41–53.
  41. Zeron MM, Hansson O, Chen N, Wellington CL, Leavitt BR, Brundin P, Hayden MR, Raymond LA (2002): Increased sensitivity to N-methyl-D-aspartate receptor-mediated excitotoxicity in a mouse model of Huntington’s disease. Neuron 33:849–860.

 goto top of outline Author Contacts

Michael S. Levine, PhD
Mental Retardation Research Center
The David Geffen School of Medicine, 760 Westwood Plaza NPI 58-258
University of California, Los Angeles, CA 90095 (USA)
Tel. +1 310 825 7595, Fax +1 310 206 5060, E-Mail mlevine@mednet.ucla.edu


 goto top of outline Article Information

Received: September 19, 2005
Accepted: October 22, 2005
Number of Print Pages : 9
Number of Figures : 4, Number of Tables : 0, Number of References : 41


 goto top of outline Publication Details

Developmental Neuroscience

Vol. 28, No. 3, Year 2006 (Cover Date: May 2006)

Journal Editor: Campagnoni, A.T. (Los Angeles, Calif.)
ISSN: 0378–5866 (print), 1421–9859 (Online)

For additional information: http://www.karger.com/DNE


Copyright / Drug Dosage / Disclaimer

Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher or, in the case of photocopying, direct payment of a specified fee to the Copyright Clearance Center.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in goverment regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

Abstract

A leading hypothesis of the cause of neuronal death in Huntington’s disease (HD) is excitotoxicity, in which subpopulations of striatal neurons are hypersensitive to glutamate release due to changes in postsynaptic N-methyl-D-aspartate receptors (NMDARs). In the present study we used RT-PCR methods on single cells and tissue to compare the expression of NMDAR subunits, NR1, NR2A and NR2B, in the striatum of R6/2 transgenic mice with their wild-type (WT) littermates at three different age groups corresponding to different symptomatic milestones (19–25 days showing no overt evidence of abnormal behavior, 38–45 days at the onset of the overt phenotype and 78–90 days displaying the full behavioral phenotype). Single-cell RT-PCR studies also examined neurons for the expression of substance P and enkephalin to define different subpopulations of medium-sized projection neurons of the striatum. The results showed a significant decrease in the percentage of cells expressing NR2A at all ages examined. The decrease in expression was not associated with any significant change in expression of NR1 or NR2B. Cells that did not express NR2A contained both enkephalin and substance P, but proportionately more cells containing enkephalin displayed decreases in NR2A. Semi-quantitative RT-PCR studies on striatal tissue in the oldest age group confirmed the significant decrease in NR2A and also showed a decrease in NR2B. These results support the hypothesis that changes in the composition of postsynaptic NMDARs occur in the R6/2 model of HD and this effect occurs early in the expression of the phenotype.



 goto top of outline Author Contacts

Michael S. Levine, PhD
Mental Retardation Research Center
The David Geffen School of Medicine, 760 Westwood Plaza NPI 58-258
University of California, Los Angeles, CA 90095 (USA)
Tel. +1 310 825 7595, Fax +1 310 206 5060, E-Mail mlevine@mednet.ucla.edu


 goto top of outline Article Information

Received: September 19, 2005
Accepted: October 22, 2005
Number of Print Pages : 9
Number of Figures : 4, Number of Tables : 0, Number of References : 41


 goto top of outline Publication Details

Developmental Neuroscience

Vol. 28, No. 3, Year 2006 (Cover Date: May 2006)

Journal Editor: Campagnoni, A.T. (Los Angeles, Calif.)
ISSN: 0378–5866 (print), 1421–9859 (Online)

For additional information: http://www.karger.com/DNE


Copyright / Drug Dosage

Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher or, in the case of photocopying, direct payment of a specified fee to the Copyright Clearance Center.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in goverment regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

References

  1. Albin RL, Young AB, Penney JB (1989): The functional anatomy of basal ganglia disorders. Trends Neurosci 12:366–375.
  2. Ariano MA, Wagle N, Grissell AE (2005): Neuronal vulnerability in mouse models of Huntington’s disease: membrane channel protein changes. J Neurosci Res 80:634–645.
  3. Beal MF, Hyman BT, Koroshetz W (1993): Do defects in mitochondrial energy metabolism underlie the pathology of neurodegenerative diseases? Trends Neurosci 16:125–131.
  4. Behe P, Stern P, Wyllie DJ, Nassar M, Schoepfer R, Colquhoun D (1995): Determination of NMDA NR1 subunit copy number in recombinant NMDA receptors. Proc R Soc Lond B Biol Sci 262:205–213.
  5. Bibb JA, Yan Z, Svenningsson P, Snyder GL, Pieribone VA, Horiuchi A, Nairn AC, Messer A, Greengard P (2000): Severe deficiencies in dopamine signaling in presymptomatic Huntington’s disease mice. Proc Natl Acad Sci USA 97:6809–6814.
  6. Bonfoco E, Krainc D, Ankarcrona M, Nicotera P, Lipton SA (1995): Apoptosis and necrosis: two distinct events induced, respectively, by mild and intense insults with N-methyl-D-aspartate or nitric oxide/superoxide in cortical cell cultures. Proc Natl Acad Sci USA 92:7162–7166.
  7. Bordelon YM, Chesselet MF (1999): Early effects of intrastriatal injections of quinolinic acid on microtubule-associated protein-2 and neuropeptides in rat basal ganglia. Neuroscience 93:843–853.
  8. Carter RJ, Lione LA, Humby T, Mangiarini L, Mahal A, Bates GP, Dunnett SB, Morton AJ (1999): Characterization of progressive motor deficits in mice transgenic for the human Huntington’s disease mutation. J Neurosci 19:3248–3257.
  9. Cepeda C, Ariano MA, Calvert CR, Flores-Hernandez J, Chandler SH, Leavitt BR, Hayden MR, Levine MS (2001a): NMDA receptor function in mouse models of Huntington disease. J Neurosci Res 66:525–539.
  10. Cepeda C, Hurst RS, Calvert CR, Hernandez-Echeagaray E, Nguyen OK, Jocoy E, Christian LJ, Ariano MA, Levine MS (2003): Transient and progressive electrophysiological alterations in the corticostriatal pathway in a mouse model of Huntington’s disease. J Neurosci 23:961–969.
  11. Cepeda C, Itri JN, Flores-Hernandez J, Hurst RS, Calvert CR, Levine MS (2001b): Differential sensitivity of medium- and large-sized striatal neurons to NMDA but not kainate receptor activation in the rat. Eur J Neurosci 14:1577–1589.
  12. Cha JH, Frey AS, Alsdorf SA, Kerner JA., Kosinski CM, Mangiarini L, Penney JB Jr, Davies SW, Bates GP, Young AB (1999): Altered neurotransmitter receptor expression in transgenic mouse models of Huntington’s disease. Philos Trans R Soc Lond B Biol Sci 354:981–989.
  13. Cha JH, Kosinski CM, Kerner JA, Alsdorf SA, Mangiarini L, Davies SW, Penney JB, Bates GP, Young AB (1998): Altered brain neurotransmitter receptors in transgenic mice expressing a portion of an abnormal human Huntington disease gene. Proc Natl Acad Sci USA 95:6480–6485.
  14. Chapman DE, Keefe KA, Wilcox KS (2003): Evidence for functionally distinct synaptic NMDA receptors in ventromedial versus dorsolateral striatum. J Neurophysiol 89:69–80.
  15. Coyle JT (1979): An animal model for Huntington’s disease. Biol Psychiatry 14:251–276.
  16. Davies SW, Turmaine M, Cozens BA, DiFiglia M, Sharp AH, Ross CA, Scherzinger E, Wanker EE, Mangiarini L, Bates GP (1997): Formation of neuronal intranuclear inclusions underlies the neurological dysfunction in mice transgenic for the HD mutation. Cell 90:537–548.
  17. Davies SW, Turmaine, M, Cozens BA, Raza AS, Mahal A, Mangiarini L, Bates GP (1999): From neuronal inclusions to neurodegeneration: neuropathological investigation of a transgenic mouse model of Huntington’s disease. Philos Trans R Soc Lond B Biol Sci 354:981–989.
  18. DiFiglia M (1990): Excitotoxic injury of the neostriatum: a model for Huntington’s disease. Trends Neurosci 13:286–289.
  19. Dunah AW, Jeong H, Griffin A, Kim YM, Standaert DG, Hersch SM, Mouradian MM, Young AB, Tanese N, Krainc D (2002): Sp1 and TAFII130 transcriptional activity disrupted in early Huntington’s disease. Science 296:2238–2243.
  20. Ferrante RJ, Andreassen OA, Jenkins BG, Dedeoglu A, Kuemmerle S, Kubilus JK, Kaddurah-Daouk R, Hersch SM, Beal MF (2000): Neuroprotective effects of creatine in a transgenic mouse model of Huntington’s disease. J Neurosci 20:4389–4397.
  21. Hollmann M, Boulter J, Maron C, Heinemann S (1994): Molecular biology of glutamate receptors. Potentiation of N-methyl-D-aspartate receptor splice variants by zinc. Ren Physiol Biochem 17:182–183.
  22. Klapstein GJ, Fisher RS, Zanjani H, Cepeda C, Jokel ES, Chesselet MF, Levine MS (2001): Electrophysiological and morphological changes in striatal spiny neurons in R6/2 Huntington’s disease transgenic mice. J Neurophysiol 86:2667–2677.
  23. Kumar SS, Huguenard JR (2003): Pathway-specific differences in subunit composition of synaptic NMDA receptors on pyramidal neurons in neocortex. J Neurosci 31:10074–10083.

    External Resources

  24. Laforet GA, Sapp E, Chase K, McIntyre C, Boyce FM, Campbell M, Cadigan BA, Warzecki L, Tagle DA, Reddy PH, Cepeda C, Calvert CR, Jokel ES, Klapstein GJ, Ariano MA, Levine MS, DiFiglia M, Aronin N (2001): Changes in cortical and striatal neurons predict behavioral and electrophysiological abnormalities in a transgenic murine model of Huntington’s disease. J Neurosci 21:9112–9123.
  25. Levine MS, Klapstein GJ, Koppel A, Gruen E, Cepeda C, Vargas ME, Jokel ES, Carpenter EM, Zanjani H, Hurst RS, Efstratiadis A, Zeitlin S, Chesselet MF (1999): Enhanced sensitivity to N-methyl-D-aspartate receptor activation in transgenic and knockin mouse models of Huntington’s disease. J Neurosci Res 58:515–532.
  26. Li H, Li SH, Johnston H, Shelbourne PF, Li XJ (2000): Amino-terminal fragments of mutant huntingtin show selective accumulation in striatal neurons and synaptic toxicity. Nat Genet 25:385–389.
  27. Li L, Fan M, Icton CD, Chen N, Leavitt BR, Hayden MR, Murphy TH, Raymond LA (2003): Role of NR2B-type NMDA receptors in selective neurodegeneration in Huntington disease. Neurobiol Aging 24:1113–1121.
  28. Lione LA, Carter RJ, Hunt MJ, Bates GP, Morton AJ, Dunnett SB (1999): Selective discrimination learning impairments in mice expressing the human Huntington’s disease mutation. J Neurosci 19:10428–10437.
  29. Luthi-Carter R, Apostol BL, Dunah AW, DeJohn MM, Farrell LA, Bates GP, Young AB, Standaert DG, Thompson LM, Cha JH (2003): Complex alteration of NMDA receptors in transgenic Huntington’s disease mouse brain: analysis of mRNA and protein expression, plasma membrane association, interacting proteins, and phosphorylation. Neurobiol Dis 14:624–636.
  30. Luthi-Carter R, Strand A, Peters NL, Solano SM, Hollingsworth ZR, Menon AS, Frey AS, Spektor BS., Penney EB, Schilling G, Ross CA, Borchelt DR, Tapscott SJ, Young AB, Cha JH, Olson JM (2000): Decreased expression of striatal signaling genes in a mouse model of Huntington’s disease. Hum Mol Genet 9:1259–1271.
  31. Martin JB, Gusella JF (1986): Huntington’s disease. Pathogenesis and management. N Engl J Med 315:267–1276.
  32. Menalled L, Zanjani H, MacKenzie L, Koppel A, Carpenter E, Zeitlin S, Chesselet MF (2000): Decrease in striatal enkephalin mRNA in mouse models of Huntington’s disease. Exp Neurol 162:328–342.
  33. Murphy KP, Carter RJ, Lione LA, Mangiarini L, Mahal A, Bates GP, Dunnett SB, Morton AJ (2000): Abnormal synaptic plasticity and impaired spatial cognition in mice transgenic for exon 1 of the human Huntington’s disease mutation. J Neurosci 20:5115–5123.
  34. Qian A, Buller AL, Johnson JW (2005): NR2 subunit-dependence of NMDA receptor channel block by external Mg2+. J Physiol 562:319–331.
  35. Sathasivam K, Hobbs C, Mangiarini L, Mahal A, Turmaine M, Doherty P, Davies SW, Bates GP (1999): Transgenic models of Huntington’s disease. Philos Trans R Soc Lond B Biol Sci 354:963–969.
  36. Schwarcz R, Foster AC, French ED, Whetsell WO Jr, Kohler C (1984): Excitotoxic models for neurodegenerative disorders. Life Sci 35:19–32.
  37. Starling AJ, Cepeda C, de Lima M, Chandler SH, Levine MS (2005): Alterations in N-methyl-D-aspartate receptor sensitivity and magnesium blockade occur early in development in the R6/2 mouse model of Huntington’s disease. J Neurosci Res 82:377–386.
  38. Vonsattel JP, DiFiglia M (1998): Huntington disease. J Neuropathol Exp Neurol 57:369–384.
  39. Vonsattel JP, Myers RH, Stevens TJ, Ferrante RJ, Bird ED, Richardson EP Jr (1985): Neuropathological classification of Huntington’s disease. J Neuropathol Exp Neurol 44:559–577.
  40. Zeron MM, Chen N, Moshaver A, Lee AT, Wellington CL, Hayden MR, Raymond LA (2001): Mutant huntingtin enhances excitotoxic cell death. Mol Cell Neurosci 17:41–53.
  41. Zeron MM, Hansson O, Chen N, Wellington CL, Leavitt BR, Brundin P, Hayden MR, Raymond LA (2002): Increased sensitivity to N-methyl-D-aspartate receptor-mediated excitotoxicity in a mouse model of Huntington’s disease. Neuron 33:849–860.