@article{IpIsaiasKuscheTekinetal.2016, author = {Ip, Chi Wang and Isaias, Ioannis U. and Kusche-Tekin, Burak B. and Klein, Dennis and Groh, Janos and O´Leary, Aet and Knorr, Susanne and Higuchi, Takahiro and Koprich, James B. and Brotchie, Jonathan M. and Toyka, Klaus V. and Reif, Andreas and Volkmann, Jens}, title = {Tor1a+/- mice develop dystonia-like movements via a striatal dopaminergic dysregulation triggered by peripheral nerve injury}, series = {Acta Neuropathologica Communications}, volume = {4}, journal = {Acta Neuropathologica Communications}, number = {108}, doi = {10.1186/s40478-016-0375-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-147839}, year = {2016}, abstract = {Isolated generalized dystonia is a central motor network disorder characterized by twisted movements or postures. The most frequent genetic cause is a GAG deletion in the Tor1a (DYT1) gene encoding torsinA with a reduced penetrance of 30-40 \% suggesting additional genetic or environmental modifiers. Development of dystonia-like movements after a standardized peripheral nerve crush lesion in wild type (wt) and Tor1a+/- mice, that express 50 \% torsinA only, was assessed by scoring of hindlimb movements during tail suspension, by rotarod testing and by computer-assisted gait analysis. Western blot analysis was performed for dopamine transporter (DAT), D1 and D2 receptors from striatal and quantitative RT-PCR analysis for DAT from midbrain dissections. Autoradiography was used to assess the functional DAT binding in striatum. Striatal dopamine and its metabolites were analyzed by high performance liquid chromatography. After nerve crush injury, we found abnormal posturing in the lesioned hindlimb of both mutant and wt mice indicating the profound influence of the nerve lesion (15x vs. 12x relative to control) resembling human peripheral pseudodystonia. In mutant mice the phenotypic abnormalities were increased by about 40 \% (p < 0.05). This was accompanied by complex alterations of striatal dopamine homeostasis. Pharmacological blockade of dopamine synthesis reduced severity of dystonia-like movements, whereas treatment with L-Dopa aggravated these but only in mutant mice suggesting a DYT1 related central component relevant to the development of abnormal involuntary movements. Our findings suggest that upon peripheral nerve injury reduced torsinA concentration and environmental stressors may act in concert in causing the central motor network dysfunction of DYT1 dystonia.}, language = {en} } @article{IsaiasSpiegelBrumbergetal.2014, author = {Isaias, Ioannis Ugo and Spiegel, J{\"o}rg and Brumberg, Joachim and Cosgrove, Kelly P. and Marotta, Giorgio and Oishi, Naoya and Higuchi, Takahiro and K{\"u}sters, Sebastian and Schiller, Markus and Dillmann, Ulrich and van Dyck, Christopher H. and Buck, Andreas and Herrmann, Ken and Schloegl, Susanne and Volkmann, Jens and Lassmann, Michael and Fassbender, Klaus and Lorenz, Reinhard and Samnick, Samuel}, title = {Nicotinic acetylcholine receptor density in cognitively intact subjects at an early stage of Parkinson's disease}, series = {Frontiers in Aging Neuroscience}, volume = {6}, journal = {Frontiers in Aging Neuroscience}, doi = {10.3389/fnagi.2014.00213}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119351}, pages = {213}, year = {2014}, abstract = {We investigated in vivo brain nicotinic acetylcholine receptor (nAChR) distribution in cognitively intact subjects with Parkinson's disease (PD) at an early stage of the disease. Fourteen patients and 13 healthy subjects were imaged with single photon emission computed tomography and the radiotracer 5-[(123)I]iodo-3-[2(S)-2-azetidinylmethoxy]pyridine ([(123)I]5IA). Patients were selected according to several criteria, including short duration of motor signs (<7 years) and normal scores at an extensive neuropsychological evaluation. In PD patients, nAChR density was significantly higher in the putamen, the insular cortex and the supplementary motor area and lower in the caudate nucleus, the orbitofrontal cortex, and the middle temporal gyrus. Disease duration positively correlated with nAChR density in the putamen ipsilateral (ρ = 0.56, p < 0.05) but not contralateral (ρ = 0.49, p = 0.07) to the clinically most affected hemibody. We observed, for the first time in vivo, higher nAChR density in brain regions of the motor and limbic basal ganglia circuits of subjects with PD. Our findings support the notion of an up-regulated cholinergic activity at the striatal and possibly cortical level in cognitively intact PD patients at an early stage of disease.}, language = {en} }