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Chapa JM, Lidauer L, Steininger A, Öhlschuster M, Potrusil T, Sigler M, Auer W, Azizzadeh M, Drillich M, Iwersen M. Erratum to “Use of a real-time location system to detect cows in distinct functional areas within a barn” (JDS Commun. 2:217–222). JDS Communications 2022; 3:163. [PMID: 36342863 PMCID: PMC9623691 DOI: 10.3168/jdsc.2022-3-2-163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Lenhart L, Seiler S, Pirpamer L, Goebel G, Potrusil T, Wagner M, Dal Bianco P, Ransmayr G, Schmidt R, Benke T, Scherfler C. Anatomically Standardized Detection of MRI Atrophy Patterns in Early-Stage Alzheimer's Disease. Brain Sci 2021; 11:brainsci11111491. [PMID: 34827490 PMCID: PMC8615991 DOI: 10.3390/brainsci11111491] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/05/2021] [Accepted: 11/06/2021] [Indexed: 11/16/2022] Open
Abstract
MRI studies have consistently identified atrophy patterns in Alzheimer’s disease (AD) through a whole-brain voxel-based analysis, but efforts to investigate morphometric profiles using anatomically standardized and automated whole-brain ROI analyses, performed at the individual subject space, are still lacking. In this study we aimed (i) to utilize atlas-derived measurements of cortical thickness and subcortical volumes, including of the hippocampal subfields, to identify atrophy patterns in early-stage AD, and (ii) to compare cognitive profiles at baseline and during a one-year follow-up of those previously identified morphometric AD subtypes to predict disease progression. Through a prospectively recruited multi-center study, conducted at four Austrian sites, 120 patients were included with probable AD, a disease onset beyond 60 years and a clinical dementia rating of ≤1. Morphometric measures of T1-weighted images were obtained using FreeSurfer. A principal component and subsequent cluster analysis identified four morphometric subtypes, including (i) hippocampal predominant (30.8%), (ii) hippocampal-temporo-parietal (29.2%), (iii) parieto-temporal (hippocampal sparing, 20.8%) and (iv) hippocampal-temporal (19.2%) atrophy patterns that were associated with phenotypes differing predominately in the presentation and progression of verbal memory and visuospatial impairments. These morphologically distinct subtypes are based on standardized brain regions, which are anatomically defined and freely accessible so as to validate its diagnostic accuracy and enhance the prediction of disease progression.
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Affiliation(s)
- Lukas Lenhart
- Department of Neurology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (L.L.); (T.P.); (T.B.)
- Department of Neuroradiology, Medical University of Innsbruck, 6020 Innsbruck, Austria;
| | - Stephan Seiler
- Center for Neurosciences, Department of Neurology, University of California, Davis, CA 95616, USA;
- Imaging of Dementia and Aging (IDeA) Laboratory, Davis, CA 95616, USA
- Department of Neurology, Medical University of Graz, 8036 Graz, Austria; (L.P.); (R.S.)
| | - Lukas Pirpamer
- Department of Neurology, Medical University of Graz, 8036 Graz, Austria; (L.P.); (R.S.)
| | - Georg Goebel
- Department of Medical Statistics, Informatics and Health Economics, Medical University of Innsbruck, Müllerstraße 44, 6020 Innsbruck, Austria;
| | - Thomas Potrusil
- Department of Neurology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (L.L.); (T.P.); (T.B.)
| | - Michaela Wagner
- Department of Neuroradiology, Medical University of Innsbruck, 6020 Innsbruck, Austria;
| | - Peter Dal Bianco
- Department of Neurology, Medical University of Vienna, 1090 Vienna, Austria;
| | - Gerhard Ransmayr
- Department of Neurology, Kepler University Hospital, 4021 Linz, Austria;
| | - Reinhold Schmidt
- Department of Neurology, Medical University of Graz, 8036 Graz, Austria; (L.P.); (R.S.)
| | - Thomas Benke
- Department of Neurology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (L.L.); (T.P.); (T.B.)
| | - Christoph Scherfler
- Department of Neurology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (L.L.); (T.P.); (T.B.)
- Correspondence: ; Tel.: +43-512-504-26276
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Chapa J, Lidauer L, Steininger A, Öhlschuster M, Potrusil T, Sigler M, Auer W, Azizzadeh M, Drillich M, Iwersen M. Use of a real-time location system to detect cows in distinct functional areas within a barn. JDS Communications 2021; 2:217-222. [PMID: 36338440 PMCID: PMC9623617 DOI: 10.3168/jdsc.2020-0050] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 03/25/2021] [Indexed: 12/02/2022]
Abstract
The RTLS achieved high accuracy in locating cows in alleys, feed bunk and cubicles. Location and time spent in important barn areas can be automatically determined and used as indicators of health. The potential of combining RTLS with other sensors technologies was discussed.
Automated sensor-based monitoring of cows has become an important tool in herd management to improve or maintain animal health and welfare. Location systems offer the ability to locate animals within the barn for, for example, artificial insemination. Furthermore, they have the potential to measure the time cows spend in important areas of the barn, which might indicate need for improvement in the management of the herd or individuals. In this study, we tested the sensor-based real-time location system (RTLS) Smartbow (SB, Smartbow GmbH) under field conditions. The objectives of this study were (1) to determine the accuracy of the system to predict the location of the cow and the agreement between visual observations and RTLS observations for the total time spent by cows in relevant areas of the barn and (2) to compare the performance of 2 different algorithms (Alg1 and Alg2) for cow location. The study was conducted on a commercial Austrian dairy farm. In total, 35 lactating cows were video recorded for 3 consecutive days. From these recordings, approximately 1 h was selected randomly each day for every cow (3 d × 35 cows). Simultaneously, location data were collected and classified by the RTLS system as dedicated to the alley, feed bunk, or cubicle on a 1-min resolution. A total of 6,030 paired observations were derived from visual observations (VO) and the RTLS and used for the final data analysis. Substantial agreement of categorical data between VO and SB was obtained by Cohen's kappa for both algorithms (Alg1 = 0.76 and Alg2 = 0.78). Similar results were achieved by both algorithms throughout the study, with a slight improvement for Alg2. The ability of the system to locate the cows in the predefined areas was assessed, and the results from Alg2 showed sensitivity, specificity, and positive predictive value of alley (74.0, 91.2, and 76.9%), feed bunk (93.5, 86.2, and 89.1%), and cubicle (90.5, 83.3, and 95.4%) and an overall accuracy of 87.6%.The correlation coefficient (r) between VO and SB for the total time cows spent (within 1 h) in the predefined areas was good to strong (r = 0.82, 0.98, and 0.92 for alley, feed bunk, and cubicle, respectively). These results show the potential of the system to automatically assess total time spent by cows in important areas of the barn for indoor settings. Future studies should focus on evaluating 24-h periods to assess time budgets and to combine technologies such as accelerometers and location systems to improve the performance of behavior prediction in dairy cows.
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Affiliation(s)
- J.M. Chapa
- FFoQSI GmbH—Austrian Competence Centre for Feed and Food Quality, Safety and Innovation, Technopark 1C, 3430 Tulln, Austria
- Clinical Unit for Herd Health Management in Ruminants, University Clinic for Ruminants, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
| | | | | | | | | | - M. Sigler
- Smartbow GmbH, 4675 Weibern, Austria
| | - W. Auer
- Smartbow GmbH, 4675 Weibern, Austria
| | - M. Azizzadeh
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, 9177948974, Iran
| | - M. Drillich
- Clinical Unit for Herd Health Management in Ruminants, University Clinic for Ruminants, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
| | - M. Iwersen
- Clinical Unit for Herd Health Management in Ruminants, University Clinic for Ruminants, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
- Corresponding author
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Potrusil T, Heshmat A, Sajedi S, Wenger C, Johnson Chacko L, Glueckert R, Schrott-Fischer A, Rattay F. Finite element analysis and three-dimensional reconstruction of tonotopically aligned human auditory fiber pathways: A computational environment for modeling electrical stimulation by a cochlear implant based on micro-CT. Hear Res 2020; 393:108001. [PMID: 32535276 DOI: 10.1016/j.heares.2020.108001] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 05/14/2020] [Accepted: 05/23/2020] [Indexed: 01/01/2023]
Abstract
The application of cochlear implants can be studied with computational models. The electrical potential distribution induced by an implanted device is evaluated with a volume conductor model, which is used as input for neuron models to simulate the reaction of cochlear neurons to micro-stimulation. In order to reliably predict the complex excitation profiles it is vital to consider an accurate representation of the human cochlea geometry including detailed three-dimensional pathways of auditory neurons reaching from the organ of Corti through the cochlea-volume. In this study, high-resolution micro-CT imaging (Δx = Δy = Δz = 3 μm) was used to reconstruct the pathways of 30 tonotopically organized nerve fiber bundles, distributed over eight octaves (11500-40 Hz). Results of the computational framework predict: (i) the peripheral process is most sensitive to cathodic stimulation (CAT), (ii) in many cases CAT elicits spikes in the peripheral terminal at threshold but with larger stimuli there is a second spike initiation site within the peripheral process, (iii) anodic stimuli (ANO) can excite the central process even at threshold, (iv) the recruitment of fibers by electrodes located in the narrowing middle- and apical turn is complex and impedes focal excitation of low frequency fibers, (v) degenerated cells which lost the peripheral process are more sensitive to CAT when their somata are totally covered with 2 membranes of a glial cell but they become ANO sensitive when the myelin covering is reduced.
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Affiliation(s)
- Thomas Potrusil
- Innsbruck Medical University, Department of Otorhinolaryngology, Laboratory for Inner Ear Biology, Anichstrasse 35, A-6020, Innsbruck, Austria
| | - Amirreza Heshmat
- Innsbruck Medical University, Department of Otorhinolaryngology, Laboratory for Inner Ear Biology, Anichstrasse 35, A-6020, Innsbruck, Austria; TU Wien, Institute for Analysis and Scientific Computing, Wiedner Hauptstraße 8-10, A- 1040, Vienna, Austria
| | - Sogand Sajedi
- TU Wien, Institute for Analysis and Scientific Computing, Wiedner Hauptstraße 8-10, A- 1040, Vienna, Austria
| | - Cornelia Wenger
- TU Wien, Institute for Analysis and Scientific Computing, Wiedner Hauptstraße 8-10, A- 1040, Vienna, Austria
| | - Lejo Johnson Chacko
- Innsbruck Medical University, Department of Otorhinolaryngology, Laboratory for Inner Ear Biology, Anichstrasse 35, A-6020, Innsbruck, Austria
| | - Rudolf Glueckert
- Innsbruck Medical University, Department of Otorhinolaryngology, Laboratory for Inner Ear Biology, Anichstrasse 35, A-6020, Innsbruck, Austria
| | - Anneliese Schrott-Fischer
- Innsbruck Medical University, Department of Otorhinolaryngology, Laboratory for Inner Ear Biology, Anichstrasse 35, A-6020, Innsbruck, Austria.
| | - Frank Rattay
- TU Wien, Institute for Analysis and Scientific Computing, Wiedner Hauptstraße 8-10, A- 1040, Vienna, Austria
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Potrusil T, Krismer F, Beliveau V, Seppi K, Müller C, Troger F, Göbel G, Steiger R, Gizewski ER, Poewe W, Scherfler C. Diagnostic potential of automated tractography in progressive supranuclear palsy variants. Parkinsonism Relat Disord 2020; 72:65-71. [DOI: 10.1016/j.parkreldis.2020.02.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 02/14/2020] [Accepted: 02/17/2020] [Indexed: 01/07/2023]
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Seki M, Seppi K, Mueller C, Potrusil T, Goebel G, Reiter E, Nocker M, Kremser C, Wildauer M, Schocke M, Gizewski ER, Wenning GK, Poewe W, Scherfler C. Diagnostic Potential of Multimodal MRI Markers in Atypical Parkinsonian Disorders. JPD 2019; 9:681-691. [DOI: 10.3233/jpd-181568] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Morinobu Seki
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
- Neuroimaging Research Core Facility, Medical University of Innsbruck, Innsbruck, Austria
| | - Klaus Seppi
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
- Neuroimaging Research Core Facility, Medical University of Innsbruck, Innsbruck, Austria
| | - Christoph Mueller
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Thomas Potrusil
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
- Neuroimaging Research Core Facility, Medical University of Innsbruck, Innsbruck, Austria
| | - Georg Goebel
- Department of Medical Statistics, Informatics and Health Economics, Medical University of Innsbruck, Innsbruck, Austria
| | - Eva Reiter
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Michael Nocker
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Christian Kremser
- Neuroimaging Research Core Facility, Medical University of Innsbruck, Innsbruck, Austria
- Department of Neuroradiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Matthias Wildauer
- Neuroimaging Research Core Facility, Medical University of Innsbruck, Innsbruck, Austria
- Department of Neuroradiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Michael Schocke
- Department of Neuroradiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Elke R. Gizewski
- Neuroimaging Research Core Facility, Medical University of Innsbruck, Innsbruck, Austria
- Department of Neuroradiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Gregor K. Wenning
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Werner Poewe
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Christoph Scherfler
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
- Neuroimaging Research Core Facility, Medical University of Innsbruck, Innsbruck, Austria
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Fischer N, Johnson Chacko L, Majerus A, Potrusil T, Riechelmann H, Schmutzhard J, Schrott-Fischer A, Glueckert R. Age-Dependent Calcium-Binding Protein Expression in the Spiral Ganglion and Hearing Performance of C57BL/6J and 129/SvJ Mice. ORL J Otorhinolaryngol Relat Spec 2019; 81:138-154. [PMID: 31170714 DOI: 10.1159/000499472] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 03/08/2019] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS Calcium-binding proteins in neurons buffer intracellular free Ca2+ ions, which interact with proteins controlling enzymatic and ion channel activity. The heterogeneous distribution of calretinin, calbindin, and parvalbumin influences calcium homeostasis, and calcium-related neuronal processes play an important role in neuronal aging and degeneration. This study evaluated age-related changes in calretinin, calbindin, and parvalbumin immune reactivity in spiral ganglion cells. METHODS A total of 16 C57BL/6J and 16 129/SvJ mice at different ages (2, 4, 7, and 12 months) were included in the study. Hearing thresholds were assessed using auditory brainstem response before inner ears were excised for further evaluation. Semiquantitative immunohistochemistry for the aforementioned calcium-binding proteins was performed at the cellular level. RESULTS The hearing thresholds of C57BL/6J and 129/SvJ mice increased significantly by 7 months of age. The average immune reactivity of calbin-din as well as the relative number of positive cells increased significantly with aging, but no significant alterations in calretinin or parvalbumin were observed. CONCLUSIONS Upregulation of calbindin could serve as a protection to compensate for functional deficits that occur with aging. Expression of both calretinin and parvalbumin seem to be stabilizing factors in murine inner ears up to the age of 12 months in C57BL/6J and 129/SvJ mice.
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Affiliation(s)
- Natalie Fischer
- Department of Otorhinolaryngology, Medical University Innsbruck, Innsbruck, Austria
| | - Lejo Johnson Chacko
- Department of Otorhinolaryngology, Medical University Innsbruck, Innsbruck, Austria
| | - Alexandra Majerus
- Department of Otorhinolaryngology, Medical University Innsbruck, Innsbruck, Austria
| | - Thomas Potrusil
- Department of Otorhinolaryngology, Medical University Innsbruck, Innsbruck, Austria
| | - Herbert Riechelmann
- Department of Otorhinolaryngology, Medical University Innsbruck, Innsbruck, Austria
| | - Joachim Schmutzhard
- Department of Otorhinolaryngology, Medical University Innsbruck, Innsbruck, Austria
| | | | - Rudolf Glueckert
- Department of Otorhinolaryngology, Medical University Innsbruck, Innsbruck, Austria.,Department of Otorhinolaryngology, Tirol Kliniken, University Clinics of Innsbruck, Innsbruck, Austria
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Glueckert R, Johnson Chacko L, Schmidbauer D, Potrusil T, Pechriggl EJ, Hoermann R, Brenner E, Reka A, Schrott-Fischer A, Handschuh S. Visualization of the Membranous Labyrinth and Nerve Fiber Pathways in Human and Animal Inner Ears Using MicroCT Imaging. Front Neurosci 2018; 12:501. [PMID: 30108474 PMCID: PMC6079228 DOI: 10.3389/fnins.2018.00501] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 07/03/2018] [Indexed: 12/18/2022] Open
Abstract
Design and implantation of bionic implants for restoring impaired hair cell function relies on accurate knowledge about the microanatomy and nerve fiber pathways of the human inner ear and its variation. Non-destructive isotropic imaging of soft tissues of the inner ear with lab-based microscopic X-ray computed tomography (microCT) offers high resolution but requires contrast enhancement using compounds with high X-ray attenuation. We evaluated different contrast enhancement techniques in mice, cat, and human temporal bones to differentially visualize the membranous labyrinth, sensory epithelia, and their innervating nerves together with the facial nerve and middle ear. Lugol’s iodine potassium iodine (I2KI) gave high soft tissue contrast in ossified specimens but failed to provide unambiguous identification of smaller nerve fiber bundles inside small bony canals. Fixation or post-fixation with osmium tetroxide followed by decalcification in EDTA provided superior contrast for nerve fibers and membranous structures. We processed 50 human temporal bones and acquired microCT scans with 15 μm voxel size. Subsequently we segmented sensorineural structures and the endolymphatic compartment for 3D representations to serve for morphometric variation analysis. We tested higher resolution image acquisition down to 3.0 μm voxel size in human and 0.5 μm in mice, which provided a unique level of detail and enabled us to visualize single neurons and hair cells in the mouse inner ear, which could offer an alternative quantitative analysis of cell numbers in smaller animals. Bigger ossified human temporal bones comprising the middle ear and mastoid bone can be contrasted with I2KI and imaged in toto at 25 μm voxel size. These data are suitable for surgical planning for electrode prototype placements. A preliminary assessment of geometric changes through tissue processing resulted in 1.6% volume increase caused during decalcification by EDTA and 0.5% volume increase caused by partial dehydration to 70% ethanol, which proved to be the best mounting medium for microCT image acquisition.
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Affiliation(s)
- Rudolf Glueckert
- Department of Otolaryngology, Medical University of Innsbruck, Innsbruck, Austria.,University Clinics Innsbruck, Tirol Kliniken, University Clinic for Ear, Nose and Throat Medicine Innsbruck, Innsbruck, Austria
| | - Lejo Johnson Chacko
- Department of Otolaryngology, Medical University of Innsbruck, Innsbruck, Austria
| | - Dominik Schmidbauer
- Department of Otolaryngology, Medical University of Innsbruck, Innsbruck, Austria.,Department of Biotechnology and Food Engineering, Management Center Innsbruck (MCI), Innsbruck, Austria
| | - Thomas Potrusil
- Department of Otolaryngology, Medical University of Innsbruck, Innsbruck, Austria
| | - Elisabeth J Pechriggl
- Department of Anatomy, Histology and Embryology, Division of Clinical and Functional Anatomy, Medical University of Innsbruck, Innsbruck, Austria
| | - Romed Hoermann
- Department of Anatomy, Histology and Embryology, Division of Clinical and Functional Anatomy, Medical University of Innsbruck, Innsbruck, Austria
| | - Erich Brenner
- Department of Anatomy, Histology and Embryology, Division of Clinical and Functional Anatomy, Medical University of Innsbruck, Innsbruck, Austria
| | - Alen Reka
- Department of Otolaryngology, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Stephan Handschuh
- VetImaging, VetCore Facility for Research, University of Veterinary Medicine, Vienna, Austria
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Seki M, Seppi K, Mueller C, Potrusil T, Goebel G, Reiter E, Nocker M, Steiger R, Wildauer M, Gizewski ER, Wenning GK, Poewe W, Scherfler C. Diagnostic potential of dentatorubrothalamic tract analysis in progressive supranuclear palsy. Parkinsonism Relat Disord 2018; 49:81-87. [PMID: 29463454 DOI: 10.1016/j.parkreldis.2018.02.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 01/04/2018] [Accepted: 02/02/2018] [Indexed: 11/17/2022]
Abstract
BACKGROUND The differentiation of progressive supranuclear palsy-parkinsonism (PSP-P) from Parkinson's disease (PD) remains a major clinical challenge. OBJECTIVES To evaluate the diagnostic potential of observer-independent assessments of microstructural integrity within infratentorial brain regions to differentiate PSP-Richardson's syndrome (PSP-RS), PSP-P and PD. METHODS 3T MRI parameters of mean diffusivity, fractional anisotropy, grey and white matter volumes from patients with PSP-RS (n = 12), PSP-P (n = 12) and mean disease duration of 2.4 ± 1.7 years were compared with PD patients (n = 20) and healthy controls (n = 23) by using statistical parametric mapping and the spatially unbiased infratentorial template. Subsequently MRI measurements of the dentatorubrothalamic tract were determined observer-independently by a validated probabilistic infratentorial atlas. The impairment of gait and postural stability was evaluated by a sum-score derived from the Unified Parkinson Disease Rating Scale. RESULTS Significant mean diffusivity increases, fractional anisotropy decreases and corresponding volume loss were localized in mesencephalic tegmentum, superior cerebellar peduncle, decussation of superior cerebellar peduncle and dentate nucleus in PSP-RS and PSP-P compared to PD and healthy controls. Altered microstructural integrity of the dentatorubrothalamic tract in PSP-RS was significantly more pronounced compared to PSP-P and correlated significantly with the gait and postural stability sum-score. Linear discriminant analysis identified diffusion tensor imaging measures of the dentatorubrothalamic tract and the gait and postural stability sum-score to classify correctly 95.5% of PRP-RS, PSP-P and PD patients. CONCLUSIONS Observer-independent analysis of microstructural integrity within the dentatorubrothalamic tract in combination with assessments of gait and postural stability differentiate PSP-P from PSP-RS and PD in early to moderately advanced stages.
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Affiliation(s)
- Morinobu Seki
- Department of Neurology, Medical University of Innsbruck, Austria; Neuroimaging Research Core Facility, Medical University of Innsbruck, Austria.
| | - Klaus Seppi
- Department of Neurology, Medical University of Innsbruck, Austria; Neuroimaging Research Core Facility, Medical University of Innsbruck, Austria
| | | | - Thomas Potrusil
- Department of Neurology, Medical University of Innsbruck, Austria; Neuroimaging Research Core Facility, Medical University of Innsbruck, Austria
| | - Georg Goebel
- Department of Medical Statistics, Informatics and Health Economics, Medical University of Innsbruck, Austria
| | - Eva Reiter
- Department of Neurology, Medical University of Innsbruck, Austria
| | - Michael Nocker
- Department of Neurology, Medical University of Innsbruck, Austria
| | - Ruth Steiger
- Neuroimaging Research Core Facility, Medical University of Innsbruck, Austria; Department of Neuroradiology, Medical University of Innsbruck, Austria
| | - Matthias Wildauer
- Neuroimaging Research Core Facility, Medical University of Innsbruck, Austria; Department of Neuroradiology, Medical University of Innsbruck, Austria
| | - Elke R Gizewski
- Neuroimaging Research Core Facility, Medical University of Innsbruck, Austria; Department of Neuroradiology, Medical University of Innsbruck, Austria
| | - Gregor K Wenning
- Department of Neurology, Medical University of Innsbruck, Austria
| | - Werner Poewe
- Department of Neurology, Medical University of Innsbruck, Austria
| | - Christoph Scherfler
- Department of Neurology, Medical University of Innsbruck, Austria; Neuroimaging Research Core Facility, Medical University of Innsbruck, Austria
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Rattay F, Potrusil T, Wenger C, Wise AK, Glueckert R, Schrott-Fischer A. Impact of morphometry, myelinization and synaptic current strength on spike conduction in human and cat spiral ganglion neurons. PLoS One 2013; 8:e79256. [PMID: 24260179 PMCID: PMC3832640 DOI: 10.1371/journal.pone.0079256] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 09/20/2013] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Our knowledge about the neural code in the auditory nerve is based to a large extent on experiments on cats. Several anatomical differences between auditory neurons in human and cat are expected to lead to functional differences in speed and safety of spike conduction. METHODOLOGY/PRINCIPAL FINDINGS Confocal microscopy was used to systematically evaluate peripheral and central process diameters, commonness of myelination and morphology of spiral ganglion neurons (SGNs) along the cochlea of three human and three cats. Based on these morphometric data, model analysis reveales that spike conduction in SGNs is characterized by four phases: a postsynaptic delay, constant velocity in the peripheral process, a presomatic delay and constant velocity in the central process. The majority of SGNs are type I, connecting the inner hair cells with the brainstem. In contrast to those of humans, type I neurons of the cat are entirely myelinated. Biophysical model evaluation showed delayed and weak spikes in the human soma region as a consequence of a lack of myelin. The simulated spike conduction times are in accordance with normal interwave latencies from auditory brainstem response recordings from man and cat. Simulated 400 pA postsynaptic currents from inner hair cell ribbon synapses were 15 times above threshold. They enforced quick and synchronous spiking. Both of these properties were not present in type II cells as they receive fewer and much weaker (∼26 pA) synaptic stimuli. CONCLUSIONS/SIGNIFICANCE Wasting synaptic energy boosts spike initiation, which guarantees the rapid transmission of temporal fine structure of auditory signals. However, a lack of myelin in the soma regions of human type I neurons causes a large delay in spike conduction in comparison with cat neurons. The absent myelin, in combination with a longer peripheral process, causes quantitative differences of temporal parameters in the electrically stimulated human cochlea compared to the cat cochlea.
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Affiliation(s)
- Frank Rattay
- Institute for Analysis and Scientific Computing, Vienna University of Technology, Vienna, Austria
| | - Thomas Potrusil
- Department of Otorhinolaryngology, Innsbruck Medical University, Innsbruck, Austria
- Faculty of Informatics, Vienna University of Technology, Vienna, Austria
| | - Cornelia Wenger
- Institute of Biophysics and Biomedical Engeneering, Faculty of Science, University of Lisbon, Lisbon, Portugal
| | | | - Rudolf Glueckert
- Department of Otorhinolaryngology, Innsbruck Medical University, Innsbruck, Austria
- University Clinics Innsbruck, Tiroler Landeskrankenanstalten, Innsbruck, Austria
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