Mice transgenic for exon 1 of Huntington's disease: properties of cholinergic and dopaminergic pre-synaptic function in the striatum
| Autor: | Jm, Vetter, Jehle T, Heinemeyer J, Franz P, Pf, Behrens, Jackisch R, Georg Bernhard Landwehrmeyer, Tj, Feuerstein |
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| Rok vydání: | 2003 |
| Předmět: |
Male
Neurotransmitter Agents Receptor Muscarinic M2 Receptors Dopamine D2 Dopamine Microdialysis Presynaptic Terminals Mice Transgenic Exons Tetrodotoxin In Vitro Techniques Receptors Muscarinic Acetylcholine Corpus Striatum Electric Stimulation Choline Choline O-Acetyltransferase Disease Models Animal Mice Huntington Disease Animals Humans Calcium Female Extracellular Space |
| Zdroj: | Europe PubMed Central |
| ISSN: | 0022-3042 |
| Popis: | In Huntington's disease (HD), neuronal loss is most prominent in the striatum leading to emotional, cognitive and progressive motor dysfunction. The R6/2 mice, transgenic for exon 1 of the HD gene, develop a neurological phenotype with similarities to these features of HD. In striatal tissue, electrically evoked release of tritiated acetylcholine (ACh) and dopamine (DA) were compared in wild-type (WT) and R6/2 mice. In R6/2 mice, the evoked release of ACh, its M2 autoreceptor-mediated maximum inhibition and its dopamine D2 heteroreceptor-mediated maximum inhibition was diminished to 51%, 74% and 87% of controls, respectively. Also, the activities of choline acetyltransferase and of synaptosomal high-affinity choline uptake decreased progressively with age in these mice. In the DA release model, however, electrical stimulation elicited equal amounts of [3H]-DA both in WT and R6/2 mice. Moreover, high-affinity DA uptake into striatal slices was similar in WT and R6/2 mice. In order to confirm these findings in vivo, intrastriatal levels of extracellular DA were measured by intracerebral microdialysis in freely moving mice: striatal DA levels were found to be equal in WT and R6/2 mice. In conclusion, in the transgenic R6/2 mice changes occur mainly in striatal cholinergic neurones and their pre-synaptic modulation, but not in the dopaminergic afferent terminals. Whether similar events also contribute to the pathogenesis of HD in humans has to be established. |
| Databáze: | OpenAIRE |
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