Movement Disorders Vol. 29, Suppl 1, 2014, pp. S1–S571 Ó 2014 International Parkinson and Movement Disorder Society

POSTER SESSION 1 Monday, June 9, 2014 12:30–14:00 Exhibition Hall B Basic Science 1 Effect of subthalamic nucleus stimulation on neural activity of pedunculopontine nucleus G. Acar, I. Sitti, Y. Temel, F. Acar (Denizli, Turkey) Objective: This study aims to determine PPN’s electrophysiological activities in rats to help future studies and to investigate the effect of subthalamic nucleus stimulation on PPN. Background: Long-duration medical treatment of Parkinson patients causes complications and morbidity. Risks in destructive surgery are releatively high, new treatment methods such as stereotactic functional surgery has been proposed recently. While sensory and behavioral processes of pedunculopontine nucleus (PPN) are well known as a locomotor center, its role on initiating and sustaining motion function in primates or rats has been also demonstrated. All functions of PPN are not fully known yet, and its DBS has been proposed as an alternative therapeutic target in treating gait problems of Parkinson’s disease recently. Methods: In this study, 14 male wistar type healthy rats with average 292 (284-317) gram weight and with the same age group were used. In the sham group, two probes were inserted, one to the STN bilaterally and the other to the right PPN to record PPN’s electrophysiological activities. In the experiment group, in addition to the same procedures used in the sham group, STN was stimulated bilaterally at 0.5 Hz, 10 Hz, 60 Hz ve 130 Hz and PPN’s electrophysiological activities were recorded before and after bilateral STN stimulations. Results: Analyzing the neural activity after the 60 Hz stimulation, it revealed that STN has a stimulus effect on PPN neurons increasing the firing rate. The PPN neurons demonstrated three different patterns of firing, burst random and regular. The majority of the neurons (68%) exhibited a regular pattern of firing in the sham group. After bilateral STN stimulation with very low (0,5 Hz and 10 Hz) and high (130 Hz) frequencies the PPN neurons maintained their firing patterns. However, after 60 Hz stimulation of STN a significant percentage of neurons (82,1 %) fired with a more regular pattern. Conclusions: The results of this study provides additional information to our understanding on PPN’s electrophysiological activities. 60 Hz STN stimulation can increase the firing rates and changes the behaviour of the PPN neurons. 2 Identification of the disease-associated prion protein degrading enzyme in vivo S. Akhter, M.M. Rahman, M.S. Islam, H.-J. Kim, S.-T. Hong (Jeonju, Korea) Objective: The goal of this study was to identify a serine protease to detoxify intraneuronal misfolded PrP. Background: Removal of misfolded prion (PrPSc) in brain is the most and important challenges in biomedical sciences. It has been reported that PrP from TSE-infected hamsters, mice and deer is degraded by lichen extracts which has serine protease activity. This degradation of PrP is not related to the intraneuronal PrP detoxification. Bacterial DegP is part of a large family of related serine proteases, members of which are found in most organisms, including humans. One of the human serine proteases, we named SP2 has high homology with bacterial heat-shock protein DegP, which protects bacterial cells from stress-induced toxicity due to misfolded proteins. Methods: We performed in vitro enzymatic assay between disease-associated mPrP and human serine proteases followed by inhibition assay by using serine protease-specific inhibitor to identify

S1 disease-associated PrP degrading serine protease (SP2). We then directed the pan-neuronal expression of wild-type mouse prion protein (mPrP) or SP2 or co-expression of mPrP with SP2 to study the ability of SP2 to protect against PrP-induced Prion disease (PrD). Results: In vitro enzymatic and inhibition assays showed that only one serine protease (SP2) out of four human serine proteases has disease-associated PrP degrading ability. Directed expression of mPrP showed accumulation of mPrP and flies showed a much more punctate pattern of immunoreactivity particularly at older ages with prominent intracellular inclusion, reduced lifespan, locomotor dysfunction and rough eyes phenotype, which indicates a toxic dominant mechanism of mPrP for the etiopathogenesis of PrD. SP2 over expression alone improved the locomotion and longevity of the fly without losing the male fertility. Upon co-expression, SP2 completely degraded accumulated mPrP in the fly brain resulted in the rescue of the mPrP-induced phenotype of premature loss of climbing ability, longevity and developmental defects in the Drosophila eye. Conclusions: Our findings demonstrated the novel insight into the detoxification pathway of intraneuronal accumulated PrP in a Drosophila model of PrD without altering normal physiology of the fly suggesting the neuroprotective role of SP2 which recapitulates the essential neuroprotective function of SP2 in humans. 3 Characterization of the epitope specificity of naturally occurring autoantibodies against a-synuclein, b-amyloid and prion protein A. Albus, J.-P. Bach, Y. Roettger, R. Dodel, M. Gold (Marburg, Germany) Objective: We characterized the specificity of the antigenantibody formation of naturally occurring autoantibodies (nAbs) against a-Synuclein (a-Syn), b-Amyloid (Ab) and Prion peptide (PrP) and their ability to recognize differential structural epitopes. Background: Abnormal aggregation of proteins induces neuronal cell loss in neurodegenerative disorders such as Alzheimer’s disease, Creutzfeldt-Jakob disease and Parkinson’s disease. nAbs are able to prevent peptide fibrillation, show a rescue effect following exposure on neurons and support microglial uptake of aggregated peptides. Methods: nAbs were isolated from intravenous immunoglobulins (IVIg) via affinity chromatography. Disposable chromatography columns were packed with iodoacetyl gel and a short part of a-Syn-, Ab- or PrP peptide, including the specific binding region for nAbs. Antibody-antigen binding experiments were performed using ELISA and Dot Blotting. Peptide fibrillation was measured with Thioflavin T. Based on fluorescence-activated cell sorting (FACS) we investigated the effect of the several nAbs on the microglial uptake. Results: nAbs against Ab, PrP and a-Syn all were able to detect the peptides Ab and PrP. In contrast, a-Syn was detected exclusively by nAbs-a-Syn. This result was also reproduced in functional assays. All three nAbs reduced the fibrillation of PrP peptide and enhanced Ab and PrP uptake in BV-2 microglial cells. Thereby nAbs-Ab and nAbs-PrP had a stronger effect than nAbs-a-Syn on PrP uptake but nAbs-a-Syn had a greater effect than nAbs-PrP on Ab uptake. Conclusions: nAbs-Ab and nAbs-PrP detect similar structural epitopes based on results of antigen binding, as well as on the effects on fibrillation in vitro and uptake by microglial cells. a-Syn however, seems to form a different structural epitope, as it is exclusively recognized by nAbs-a-Syn. Interestingly, nAbs-a-Syn recognize Ab and PrP. We conclude that nAbs-Ab und nAbs-PrP recognize the same structural epitope whereas nAbs-a-Syn recognize a different structural epitope and might be more specific for its antigen. 4 Interplay of striatal projection neurons in the generation of dyskinesia in Parkinson’s disease C. Alcacer, J. Jakobsson, M.A. Cenci (Lund, Sweden) Objective: To determine the role of striatal projection neurons forming the “direct pathway” (dSPN) or the “indirect pathway”

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(iSPN) in shaping the motor response to L-DOPA in a mouse model of hemiparkinsonism. Background: L-DOPA is the most effective treatment for Parkinson’s disease (PD). However, this treatment is complicated by LDOPA-induced dyskinesia (LID). Current theories assume that LID results from an imbalance in the activity of the direct and indirect pathway favoring an overactivity of the dSPN. Up to this day, the above theory has not been verified with specific experiments. Methods: To selectively activate dSPN or iSPN in a mouse model of PD and LID we have developed a chemical-genetic approach based on targeting the expression of designer receptors exclusively activated by designer drugs (DREADD) selectively to dSPN and/or iSPN. DREADD are only activated by systemic administration of the inert compound, clozapine-N-oxide (CNO). Adeno-associated viral vectors (AAV) coding for Cre-inducible, mCherry-tagged DREADD constructs were injected in the striatum in D1-Cre and A2a-Cre transgenic mice (to target dSPN or iSPN, respectively). As a DREADD, we have thus far used the modified Gq-coupled human M3 muscarinic receptor (hM3Dq) whose stimulation by CNO triggers the activation of Gq-mediated signaling. Results: AAV-delivered Gq-DREADD exerted functional effects in vivo. As expected, the striatal transfection of the Gq-DREADD followed by treatment with CNO induced opposite effects on general motor activity in D1-Cre and A2a-Cre mice (increased and decreased activity, respectively). In hemiparkinsonian mice, dyskinesia was induced with an increasing dose regimen of L-DOPA. Once dyskinesia was established, mice were pre-treated with CNO 20 minutes before L-DOPA. We have thus far performed this experiment only in A2a-Cre mice. The results show that activation of the iSPN by CNO reduced LID in A2a-Cre mice. Conclusions: This is the first study to use a DREADD-based chemical-genetic approach to explore the cellular pathophysiology of PD and dyskinesia. Our results show that AAV-Gq-DREADD integrated in dSPN and iSPN and mediated robust changes in motor activity when stimulated with CNO. In A2a-Cre hemiparkinsonian mice treated with L-DOPA, pre-treatment with CNO reduced the expression of dyskinetic behaviors. Thus, DREADD-CNO activation of the ‘indirect pathway’ may provide a new route for the treatment of LID. 5 Age-related alterations in astroglial proteins in the substantia nigra pars compacta of Asian Indians P.A. Alladi, H.J. Jyothi, D.H.J. Vidyadhara, S.K. Parmar, A. Mahadevan, S.K. Shankar, T.R. Raju (Bangalore, India) Objective: To assess the astroglial responses in aging human substantia nigra pars compacta (SNpc) as age is a risk factor for Parkinson’s disease (PD). Background: Aging is a complex biological phenomenon modulated by neuron-glial interactions. PD is less prevalent in AsianIndians, probably due to the absence of age related nigral neuronal loss. However in this population, the factors like age related increase in Marinesco bodies, a-synuclein expression etc. reflect presence of only sub-threshold neurodegeneration and hence lesser impact of aging. Effect of aging on nigral astrocytes in human SNpc is not know. Methods: We used stereology to quantify number of glia, on Nissl stained sections. We studied the expression of glial fibrillary acidic protein (GFAP) and s100b by immunohistochemistry and densitometry based image analysis, on cryosections obtained from autopsied human midbrains (GW28-88yrs; n537). The morphological changes, intensity and total stained area were measured and analyzed. Results: The glial numbers increased in two distinct phases. The first phase of prominent increase was seen during development i.e. during the transition from fetal age to the first postnatal year, which may be related to physiological gliogenesis. The second phase of mild non-significant increase from middle to old age may reflect mild age-related gliosis. S100b expression levels remained comparable through aging, suggesting absence of marked calcium overload with age. Although overall GFAP expression showed only a moderate

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increase, changes in astrocytic morphology were seen. We found that most of the astrocytes of younger subjects had smaller soma and bore long slender processes, whereas majority of astrocytes of the older subjects had relatively larger soma and shorter thicker processes. Conclusions: Our findings suggest the absence of significant agerelated astrogliosis in human nigra and match the findings reported in non-human primates. The changes were mild compared to that observed in brains of PD patients. The morphological changes in the glia of the elderly group reminisce partly activated stage. The merely subtle agerelated morphological changes in human nigral glia, correlate well with the sub-threshold neurodegeneration seen in our population. Thus our findings attribute the astrocytes with only a participatory role in aging and mirror the sub-threshold degeneration observed in nigra of Asian-Indians. 6 Cognitive impairments in a mouse model of progressive midbrain dopaminergic neuron dysfunction A. Alvarsson, N. Schintu, T. Perlmann, P. Svenningsson (Stockholm, Sweden) Objective: To investigate cognitive functions in cNurr1DATCreER mice, a model of progressive midbrain dopaminergic (mDA) neuron dysfunction. Background: Nurr1 is a transcription factor involved in the differentiation and maintenance of functional mDA neurons, and has been associated with Parkinson’s disease (PD). cNurr1DATCreER knock-out (cNurr1 KO) mice, in which the Nurr1 gene has been selectively ablated in dopaminergic neurons, develop a progressive pathology characterized by fragmented dopaminergic axons and dendrites, reduced levels of striatal dopamine, and impaired motor behavior. This mouse model recapitulates early features of PD, but further characterization of non-motor functions is warranted. Methods: Nurr1 was conditionally ablated by tamoxifen treatment of 5 weeks old Nurr1 floxed mice. Adult (4-7 months) and old (12 months) cNurr1 KO and corresponding wild type (WT) animals were used to evaluate the progressive effect of mDA dysfunction upon aging. Working memory was evaluated using the T-maze, short-term object memory and exploratory behavior were assessed using the Novel Object Recognition test, and emotional memory was assessed in the Passive Avoidance test. Results: Spontaneous alternation behavior in the T-maze was impaired in adult and old cNurr1 KO mice, but remained intact in WT mice also upon aging, indicating that working memory impairments present early in the pathology induced by conditional Nurr1ablation. Old cNurr1 KO mice spent less time exploring objects in an open field arena compared to WT mice during the training session of the NOR test (p