| 1. |
- Bode, Felix J., et al.
(author)
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Increased numbers of motor activity peaks during light cycle are associated with reductions in adrenergic alpha(2)-receptor levels in a transgenic Huntington's disease rat model
- 2009
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In: Behavioural Brain Research. - : Elsevier BV. - 0166-4328. ; 205:1, s. 175-182
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Journal article (peer-reviewed)abstract
- Huntington's disease (HID) is a neurodegenerative disorder caused by a CAG repeat expansion in the HD gene. Besides psychiatric, motor and cognitive symptoms, HD patients suffer from sleep disturbances. In order to screen a rat model transgenic for HD (tgHD rats) for sleep-wake cycle dysregulation, we monitored their circadian activity peaks in the present study. TgHD rats of both sexes showed hyperactivity during the dark cycle and more frequent light cycle activity peaks indicative for a disturbed sleep-wake cycle. Focusing on males at the age of 4 and 14 months, analyses of receptor levels in the hypothalamus and the basal forebrain revealed that 5-HT2A- and adrenergic alpha(2)-receptor densities in these regions were significantly altered in tgHD rats compared to their wild-type littermates. Adrenergic receptor densities correlated negatively with the light cycle hyperactivity peaks at later stages of the disease in male tgHD rats. Furthermore, reduced leptin levels, a feature associated with circadian misalignment, were present. Our study demonstrates that the male tgHD rat is a suitable model to investigate HD associated sleep alterations. Further studies are warranted to elucidate the role of adrenergic- and 5-HT2A- receptors as therapeutic targets for dysregulation of the circadian activity in HD. (C) 2009 Elsevier B.V. All rights reserved.
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| 2. |
- Bode, Felix J., et al.
(author)
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Sex differences in a transgenic rat model of Huntington's disease: decreased 17 beta-estradiol levels correlate with reduced numbers of DARPP32(+) neurons in males
- 2008
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In: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 17:17, s. 2595-2609
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Journal article (peer-reviewed)abstract
- Recent clinical studies have highlighted that female sex hormones represent potential neuroprotective mediators against damage caused by acute and chronic brain diseases. This evidence has been confirmed by experimental studies documenting the protective role of female sex hormones both in vitro and in vivo, although these studies did not specifically focus on Huntington's disease (HD). We therefore investigated the onset and course of HD in female and male transgenic (tg) HD (CAG(n51)) and control rats across age and focused on three aspects: (i) behavioral and physiological alterations (energy expenditure, home-cage activity, emotional disturbance and motor dysfunction), (ii) morphological markers (numbers and characteristics of striatal DARPP32(+) medium-sized spiny neurons (MSNs) and dopamine receptor autoradiography) and (iii) peripheral sex hormone levels as well as striatal estrogen receptor expression. Independent of their sex, tgHD rats exhibited increased levels of food intake, elevated home-cage activity scores and anxiolytic-like behavior, whereas only males showed an impairment of motor function. In line with the latter finding, loss and atrophy of DARPP32(+) MSNs were apparent only in male tgHD rats. This result was associated with a decreased striatal dopamine D1 receptor density and lower plasma levels of 17 beta-estradiol at the age of 14 months. As DARPP32(+) MSNs expressed both alpha-and beta-estrogen receptors and showed a correlation between cell numbers and 17 beta-estradiol levels, our findings suggest sex-related differences in the HD phenotype pointing to a substantial neuroprotective effect of sex hormones and opening new perspectives on the therapy of HD.
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| 3. |
- Huebener, Jeannette, et al.
(author)
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Automated Behavioral Phenotyping Reveals Presymptomatic Alterations in a SCA3 Genetrap Mouse Model
- 2012
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In: Journal of Genetics and Genomics. - : Elsevier BV. - 1673-8527. ; 39:6, s. 287-299
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Journal article (peer-reviewed)abstract
- Characterization of disease models of neurodegenerative disorders requires a systematic and comprehensive phenotyping in a highly standardized manner. Therefore, automated high-resolution behavior test systems such as the homecage based LabMaster system are of particular interest. We demonstrate the power of the automated LabMaster system by discovering previously unrecognized features of a recently characterized atxn3 mutant mouse model. This model provided neurological symptoms including gait ataxia, tremor, weight loss and premature death at the age of 12 months usually detectable just 2 weeks before the mice died. Moreover, using the LabMaster system we were able to detect hypoactivity in presymptomatic mutant mice in the dark as well as light phase. Additionally, we analyzed inflammation, immunological and hematological parameters, which indicated a reduced immune defense in phenotypic mice. Here we demonstrate that a detailed characterization even of organ systems that are usually not affected in SCA3 is important for further studies of pathogenesis and required for the preclinical therapeutic studies.
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