25 results on '"Rankovic V"'
Search Results
2. Effect of alcoholic fermentation on the quality of grape brandies
- Author
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Vukosavljević Vera, Ranković Vesna, Žunić Dragoljub, and Matijašević Saša
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grape brandy ,grape ,higher alcohols ,variety ,Neoplanta ,Agriculture - Abstract
Grape brandy is a product obtained by fermentation and distillation of crushed grapes of cultivated grapevine Vitis vinifera. Grape brandy quality depends on many factors such as: grapevine varieties, climate, soil, time and method of distillation, storage methods and other distillates. The grapevine variety 'Neoplanta' grown in the experimental field of the PD 'Center for Viticulture and Enology' in Niš was used in the experiment. Tests were performed in the laboratory of the Centre. Healthy grapes of harvest maturity were squashed by a stalk-removing electric crusher. Fermentation was performed in plastic containers in the presence of the indigenous microflora of wine yeasts. This paper presents the influence of pH and inorganic nitrogen added to the fermentation medium on the content of volatile components and concentrations of higher alcohols.
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- 2015
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3. Risk assessment in coronary patients undergoing abdominal nonvascular surgery
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Karapandzic Vesna, Matic Mihailo, Pesko Predrag, Rankovic Vitomir, and Milicic Biljana
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coronary artery disease ,risk assessment ,noncardiac surgery ,cardiac complications ,Medicine - Published
- 2009
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4. Serous microcystic adenoma of the head of the pancreas causing an obstructive jaundice
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Čolović Radoje, Grubor Nikica, Micev Marjan, Ranković Vitomir, Matić Slavko, and Latinčić Stojan
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pancreas ,exocrine ,adenoma ,diagnosis ,differential ,jaundice ,obstructive ,pancreaticoduodenectomy ,Medicine (General) ,R5-920 - Abstract
Background. Serous microcystic adenoma is a rare benign tumor of the exocrine pancreas originating from the ductal system and composed of a large number of small cysts covered by cuboid cells, filled with clear serous fluid and separated with fibrocolagenous stroma. Most frequently it appears in women in 7th and 8th decades, in the distal pancreas. It shows a very low malignant potential. In 2/3 of patients symptoms are uncharacteristic and in 1/3 they are absent. When localized within the head of the pancreas it rarely causes an obstructive jaundice. Case report. We presented a 61-year-old female patient who for months had had mild and nonspecific abdominal symptoms developing to progressive obstructive jaundice. At surgery we revealed a rather large policystic mass of the head of the pancreas causing not only obstructive jaundice but also a venous stasis by compression and dislocation of the portomesenteric vein. The tumor was removed with pylorus preserving cephalic duodenopancreatectomy (Whipple's procedure modified by Longmire-Traverso). Histology confirmed serous microcystic adenoma of the pancreas. The postoperative recovery was uneventful and preoperative symptoms disappeared. Conclusion. Although very rare, serous microcystic adenoma might appear within the head of the pancreas and has to be taken into consideration in differential diagnosis of cystic lesions of the head of the pancreas. Very rarely the tumour might cause obstructive jaundice. Surgical resection, which might be demanding, leads to complete recovery.
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- 2008
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5. Liver cystic echinococcosis in humans — a study of 30 cases
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Ćulafić D., Katić-Radivojević S., Kerkez M., Vukčević M., Ranković V., and Stefanović D.
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Echinococcus granulosus ,liver ,humans ,diagnostic ,treatment ,Microbiology ,QR1-502 - Published
- 2007
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6. Combined spinal-epidural analgesia: Then and now
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Stamenković Dušica M., Slavković Zoran V., Gerić Veselin V., Filipović Nikola, Šurbatović Maja, and Ranković Vitomir I.
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anesthesia, epidural ,anesthesia, spinal ,methods ,analgesia ,Medicine (General) ,R5-920 - Published
- 2007
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7. Control of industrial robot using neural network compensator
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Ranković Vesna and Nikolić Ilija
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Mechanics of engineering. Applied mechanics ,TA349-359 - Abstract
In the paper is considered synthesis of the controller with tachometric feedback with feed forward compensation of disturbance torque, velocity and acceleration errors. It is difficult to obtain the desired control performance when the control algorithm is only based on the robot dynamic model. We use the neural network to generate auxiliary joint control torque to compensate these uncertainties. The two-layer neural network is used as the compensator. The main task of control system here is to track the required trajectory. Simulations are done in MATLAB for RzRyRy robot minimal configuration.
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- 2005
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8. Disseminated subcutaneous fat necrosis and elbow joint arthritis as a complication of pancreatitis
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Čolović Radoje, Grubor Nikica, Radak Vladimir, Čolović Nataša, Ranković Vitomir, Latinčić Stojan, and Matić Slavko
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pancreatitis ,fat necrosis ,jaundice ,elbow joint ,arthritis ,diagnosis ,Medicine (General) ,R5-920 - Abstract
Background. Intraabdominal fat necrosis of the retroperitoneum, mesenthery and omentum is a frequent complication of acute pancreatitis. Very rarely, during the disease multiple aseptic subcutaneous fat necrosis, polyarthritis, polyserositis, vasculitis, subcutaneous nodi and eosinophylia, isolated or in combination, may appear. They are known as "pancreatic disease syndrome". Case report. We presented a female patient, 43-year-old, in whom in the course of acute interstitial billiary pancreatitis had occur red multiple localized aseptic necrosis of subcutaneous fat tissue of extremities appeared mostly around the talocrural and wrist joints requiring multiple incision, as well as aseptic elbow joints arthritis requiring puncture of one elbow joint. The symptoms were followed by a prolonged febrility that settled within several weeks. Conclusion. Localized disseminated fat necrosis around joints, arthritis of major joints, alone or with some of other symptoms of the "pancreatic disease syndrome" have to be considered as a probable sign of pancreatitis, even in the abscence of major abdominal symptoms.
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- 2008
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9. CaBP1 and 2 enable sustained Ca V 1.3 calcium currents and synaptic transmission in inner hair cells.
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Oestreicher D, Chepurwar S, Kusch K, Rankovic V, Jung S, Strenzke N, and Pangrsic T
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- Animals, Mice, Calcium metabolism, Hair Cells, Auditory, Inner metabolism, Hair Cells, Auditory, Inner physiology, Synaptic Transmission physiology, Mice, Knockout, Calcium Channels, L-Type metabolism, Calcium Channels, L-Type genetics, Calcium-Binding Proteins metabolism, Calcium-Binding Proteins genetics
- Abstract
To encode continuous sound stimuli, the inner hair cell (IHC) ribbon synapses utilize calcium-binding proteins (CaBPs), which reduce the inactivation of their Ca
V 1.3 calcium channels. Mutations in the CABP2 gene underlie non-syndromic autosomal recessive hearing loss DFNB93. Besides CaBP2, the structurally related CaBP1 is highly abundant in the IHCs. Here, we investigated how the two CaBPs cooperatively regulate IHC synaptic function. In Cabp1/2 double-knockout mice, we find strongly enhanced CaV 1.3 inactivation, slowed recovery from inactivation and impaired sustained exocytosis. Already mild IHC activation further reduces the availability of channels to trigger synaptic transmission and may effectively silence synapses. Spontaneous and sound-evoked responses of spiral ganglion neurons in vivo are strikingly reduced and strongly depend on stimulation rates. Transgenic expression of CaBP2 leads to substantial recovery of IHC synaptic function and hearing sensitivity. We conclude that CaBP1 and 2 act together to suppress voltage- and calcium-dependent inactivation of IHC CaV 1.3 channels in order to support sufficient rate of exocytosis and enable fast, temporally precise and indefatigable sound encoding., Competing Interests: DO, SC, KK, VR, SJ, NS, TP No competing interests declared, (© 2024, Oestreicher et al.)- Published
- 2024
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10. Slow kinesin-dependent microtubular transport facilitates ribbon synapse assembly in developing cochlear inner hair cells.
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Voorn RA, Sternbach M, Jarysta A, Rankovic V, Tarchini B, Wolf F, and Vogl C
- Abstract
Sensory synapses are characterized by electron-dense presynaptic specializations, so-called synaptic ribbons. In cochlear inner hair cells (IHCs), ribbons play an essential role as core active zone (AZ) organizers, where they tether synaptic vesicles, cluster calcium channels and facilitate the temporally-precise release of primed vesicles. While a multitude of studies aimed to elucidate the molecular composition and function of IHC ribbon synapses, the developmental formation of these signalling complexes remains largely elusive to date. To address this shortcoming, we performed long-term live-cell imaging of fluorescently-labelled ribbon precursors in young postnatal IHCs to track ribbon precursor motion. We show that ribbon precursors utilize the apico-basal microtubular (MT) cytoskeleton for targeted trafficking to the presynapse, in a process reminiscent of slow axonal transport in neurons. During translocation, precursor volume regulation is achieved by highly dynamic structural plasticity - characterized by regularly-occurring fusion and fission events. Pharmacological MT destabilization negatively impacted on precursor translocation and attenuated structural plasticity, whereas genetic disruption of the anterograde molecular motor Kif1a impaired ribbon volume accumulation during developmental maturation. Combined, our data thus indicate an essential role of the MT cytoskeleton and Kif1a in adequate ribbon synapse formation and structural maintenance.
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- 2024
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11. Analyzing efficacy, stability, and safety of AAV-mediated optogenetic hearing restoration in mice.
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Bali B, Gruber-Dujardin E, Kusch K, Rankovic V, and Moser T
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- Animals, Brain, Hearing genetics, Mice, Neurons metabolism, Optogenetics, Spiral Ganglion metabolism
- Abstract
AAV-mediated optogenetic neural stimulation has become a clinical approach for restoring function in sensory disorders and feasibility for hearing restoration has been indicated in rodents. Nonetheless, long-term stability and safety of AAV-mediated channelrhodopsin (ChR) expression in spiral ganglion neurons (SGNs) remained to be addressed. Here, we used longitudinal studies on mice subjected to early postnatal administration of AAV2/6 carrying fast gating ChR f-Chrimson under the control of the human synapsin promoter unilaterally to the cochlea. f-Chrimson expression in SGNs in both ears and the brain was probed in animals aged 1 mo to 2 yr. f-Chrimson was observed in SGNs at all ages indicating longevity of ChR-expression. SGN numbers in the AAV-injected cochleae declined with age faster than in controls. Investigations were extended to the brain in which viral transduction was observed across the organ at varying degrees irrespective of age without observing viral spread-related pathologies. No viral DNA or virus-related histopathological findings in visceral organs were encountered. In summary, our study demonstrates life-long (24 mo in mice) expression of f-Chrimson in SGNs upon single AAV-dosing of the cochlea., (© 2022 Bali et al.)
- Published
- 2022
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12. Cabp2 -Gene Therapy Restores Inner Hair Cell Calcium Currents and Improves Hearing in a DFNB93 Mouse Model.
- Author
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Oestreicher D, Picher MM, Rankovic V, Moser T, and Pangrsic T
- Abstract
Clinical management of auditory synaptopathies like other genetic hearing disorders is currently limited to the use of hearing aids or cochlear implants. However, future gene therapy promises restoration of hearing in selected forms of monogenic hearing impairment, in which cochlear morphology is preserved over a time window that enables intervention. This includes non-syndromic autosomal recessive hearing impairment DFNB93, caused by defects in the CABP2 gene. Calcium-binding protein 2 (CaBP2) is a potent modulator of inner hair cell (IHC) voltage-gated calcium channels Ca
V 1.3. Based on disease modeling in Cabp2-/- mice, DFNB93 hearing impairment has been ascribed to enhanced steady-state inactivation of IHC CaV 1.3 channels, effectively limiting their availability to trigger synaptic transmission. This, however, does not seem to interfere with cochlear development and does not cause early degeneration of hair cells or their synapses. Here, we studied the potential of a gene therapeutic approach for the treatment of DFNB93. We used AAV2/1 and AAV-PHP.eB viral vectors to deliver the Cabp2 coding sequence into IHCs of early postnatal Cabp2-/- mice and assessed the level of restoration of hair cell function and hearing. Combining in vitro and in vivo approaches, we observed high transduction efficiency, and restoration of IHC CaV 1.3 function resulting in improved hearing of Cabp2-/- mice. These preclinical results prove the feasibility of DFNB93 gene therapy., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Oestreicher, Picher, Rankovic, Moser and Pangrsic.)- Published
- 2021
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13. Utility of red-light ultrafast optogenetic stimulation of the auditory pathway.
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Bali B, Lopez de la Morena D, Mittring A, Mager T, Rankovic V, Huet AT, and Moser T
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- Animals, Auditory Pathways, Channelrhodopsins genetics, Mice, Spiral Ganglion, Cochlear Implants, Optogenetics
- Abstract
Optogenetic stimulation of spiral ganglion neurons (SGNs) in the ear provides a future alternative to electrical stimulation used in current cochlear implants. Here, we employed fast and very fast variants of the red-light-activated channelrhodopsin (ChR) Chrimson (f-Chrimson and vf-Chrimson) to study their utility for optogenetic stimulation of SGNs in mice. The light requirements were higher for vf-Chrimson than for f-Chrimson, even when optimizing membrane expression of vf-Chrimson by adding potassium channel trafficking sequences. Optogenetic time and intensity coding by single putative SGNs were compared with coding of acoustic clicks. vf-Chrimson enabled putative SGNs to fire at near-physiological rates with good temporal precision up to 250 Hz of stimulation. The dynamic range of SGN spike rate coding upon optogenetic stimulation was narrower than for acoustic clicks but larger than reported for electrical stimulation. The dynamic range of spike timing, on the other hand, was more comparable for optogenetic and acoustic stimulation. In conclusion, f-Chrimson and vf-Chrimson are promising candidates for optogenetic stimulation of SGNs in auditory research and future cochlear implants., (© 2021 The Authors. Published under the terms of the CC BY 4.0 license.)
- Published
- 2021
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14. Developing Fast, Red-Light Optogenetic Stimulation of Spiral Ganglion Neurons for Future Optical Cochlear Implants.
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Huet AT, Dombrowski T, Rankovic V, Thirumalai A, and Moser T
- Abstract
Optogenetic stimulation of type I spiral ganglion neurons (SGNs) promises an alternative to the electrical stimulation by current cochlear implants (CIs) for improved hearing restoration by future optical CIs (oCIs). Most of the efforts in using optogenetic stimulation in the cochlea so far used early postnatal injection of viral vectors carrying blue-light activated channelrhodopsins (ChRs) into the cochlea of mice. However, preparing clinical translation of the oCI requires ( i ) reliable and safe transduction of mature SGNs of further species and ( ii ) use of long-wavelength light to avoid phototoxicity. Here, we employed a fast variant of the red-light activated channelrhodopsin Chrimson (f-Chrimson) and different AAV variants to implement optogenetic SGN stimulation in Mongolian gerbils. We compared early postnatal (p8) and adult (>8 weeks) AAV administration, employing different protocols for injection of AAV-PHP.B and AAV2/6 into the adult cochlea. Success of the optogenetic manipulation was analyzed by optically evoked auditory brainstem response (oABR) and immunohistochemistry of mid-modiolar cryosections of the cochlea. In order to most efficiently evaluate the immunohistochemical results a semi-automatic procedure to identify transduced cells in confocal images was developed. Our results indicate that the rate of SGN transduction is significantly lower for AAV administration into the adult cochlea compared to early postnatal injection. SGN transduction upon AAV administration into the adult cochlea was largely independent of the chosen viral vector and injection approach. The higher the rate of SGN transduction, the lower were oABR thresholds and the larger were oABR amplitudes. Our results highlight the need to optimize viral vectors and virus administration for efficient optogenetic manipulation of SGNs in the adult cochlea for successful clinical translation of SGN-targeting gene therapy and of the oCI., Competing Interests: TM is a co-founder and CEO of OptoGenTech company. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Huet, Dombrowski, Rankovic, Thirumalai and Moser.)
- Published
- 2021
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15. Overloaded Adeno-Associated Virus as a Novel Gene Therapeutic Tool for Otoferlin-Related Deafness.
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Rankovic V, Vogl C, Dörje NM, Bahader I, Duque-Afonso CJ, Thirumalai A, Weber T, Kusch K, Strenzke N, and Moser T
- Abstract
Hearing impairment is the most common sensory disorder in humans. So far, rehabilitation of profoundly deaf subjects relies on direct stimulation of the auditory nerve through cochlear implants. However, in some forms of genetic hearing impairment, the organ of Corti is structurally intact and therapeutic replacement of the mutated gene could potentially restore near natural hearing. In the case of defects of the otoferlin gene ( OTOF ), such gene therapy is hindered by the size of the coding sequence (~6 kb) exceeding the cargo capacity (<5 kb) of the preferred viral vector, adeno-associated virus (AAV). Recently, a dual-AAV approach was used to partially restore hearing in deaf otoferlin knock-out ( Otof- KO) mice. Here, we employed in vitro and in vivo approaches to assess the gene-therapeutic potential of naturally-occurring and newly-developed synthetic AAVs overloaded with the full-length Otof coding sequence. Upon early postnatal injection into the cochlea of Otof- KO mice, overloaded AAVs drove specific expression of otoferlin in ~30% of all IHCs, as demonstrated by immunofluorescence labeling and polymerase chain reaction. Recordings of auditory brainstem responses and a behavioral assay demonstrated partial restoration of hearing. Together, our results suggest that viral gene therapy of DFNB9-using a single overloaded AAV vector-is indeed feasible, reducing the complexity of gene transfer compared to dual-AAV approaches., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Rankovic, Vogl, Dörje, Bahader, Duque-Afonso, Thirumalai, Weber, Kusch, Strenzke and Moser.)
- Published
- 2021
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16. Viral rhodopsins 1 are an unique family of light-gated cation channels.
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Zabelskii D, Alekseev A, Kovalev K, Rankovic V, Balandin T, Soloviov D, Bratanov D, Savelyeva E, Podolyak E, Volkov D, Vaganova S, Astashkin R, Chizhov I, Yutin N, Rulev M, Popov A, Eria-Oliveira AS, Rokitskaya T, Mager T, Antonenko Y, Rosselli R, Armeev G, Shaitan K, Vivaudou M, Büldt G, Rogachev A, Rodriguez-Valera F, Kirpichnikov M, Moser T, Offenhäusser A, Willbold D, Koonin E, Bamberg E, and Gordeliy V
- Subjects
- Animals, Calcium metabolism, Cations, Cells, Cultured, Channelrhodopsins metabolism, HEK293 Cells, Humans, Ion Channel Gating, Light, Neurons metabolism, Phylogeny, Protein Conformation, Rats, Wistar, Rhodopsin genetics, Structure-Activity Relationship, Viral Proteins genetics, X-Ray Diffraction, Phytoplankton virology, Rhodopsin chemistry, Rhodopsin metabolism, Viral Proteins chemistry, Viral Proteins metabolism
- Abstract
Phytoplankton is the base of the marine food chain as well as oxygen and carbon cycles and thus plays a global role in climate and ecology. Nucleocytoplasmic Large DNA Viruses that infect phytoplankton organisms and regulate the phytoplankton dynamics encompass genes of rhodopsins of two distinct families. Here, we present a functional and structural characterization of two proteins of viral rhodopsin group 1, OLPVR1 and VirChR1. Functional analysis of VirChR1 shows that it is a highly selective, Na
+ /K+ -conducting channel and, in contrast to known cation channelrhodopsins, it is impermeable to Ca2+ ions. We show that, upon illumination, VirChR1 is able to drive neural firing. The 1.4 Å resolution structure of OLPVR1 reveals remarkable differences from the known channelrhodopsins and a unique ion-conducting pathway. Thus, viral rhodopsins 1 represent a unique, large group of light-gated channels (viral channelrhodopsins, VirChR1s). In nature, VirChR1s likely mediate phototaxis of algae enhancing the host anabolic processes to support virus reproduction, and therefore, might play a major role in global phytoplankton dynamics. Moreover, VirChR1s have unique potential for optogenetics as they lack possibly noxious Ca2+ permeability.- Published
- 2020
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17. μLED-based optical cochlear implants for spectrally selective activation of the auditory nerve.
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Dieter A, Klein E, Keppeler D, Jablonski L, Harczos T, Hoch G, Rankovic V, Paul O, Jeschke M, Ruther P, and Moser T
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- Cochlea, Cochlear Nerve, Humans, Spiral Ganglion, Cochlear Implantation, Cochlear Implants
- Abstract
Electrical cochlear implants (eCIs) partially restore hearing and enable speech comprehension to more than half a million users, thereby re-connecting deaf patients to the auditory scene surrounding them. Yet, eCIs suffer from limited spectral selectivity, resulting from current spread around each electrode contact and causing poor speech recognition in the presence of background noise. Optogenetic stimulation of the auditory nerve might overcome this limitation as light can be conveniently confined in space. Here, we combined virus-mediated optogenetic manipulation of cochlear spiral ganglion neurons (SGNs) and microsystems engineering to establish acute multi-channel optical cochlear implant (oCI) stimulation in adult Mongolian gerbils. oCIs based on 16 microscale thin-film light-emitting diodes (μLEDs) evoked tonotopic activation of the auditory pathway with high spectral selectivity and modest power requirements in hearing and deaf gerbils. These results prove the feasibility of μLED-based oCIs for spectrally selective activation of the auditory nerve., (© 2020 The Authors. Published under the terms of the CC BY 4.0 license.)
- Published
- 2020
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18. Toward the Optical Cochlear Implant.
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Dombrowski T, Rankovic V, and Moser T
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- Animals, Deafness rehabilitation, Humans, Prosthesis Design, Auditory Pathways physiopathology, Cochlear Implantation instrumentation, Cochlear Implants, Optogenetics, Speech Perception
- Abstract
When hearing fails, cochlear implants (CIs) provide open speech perception to most of the currently half a million CI users. CIs bypass the defective sensory organ and stimulate the auditory nerve electrically. The major bottleneck of current CIs is the poor coding of spectral information, which results from wide current spread from each electrode contact. As light can be more conveniently confined, optical stimulation of the auditory nerve presents a promising perspective for a fundamental advance of CIs. Moreover, given the improved frequency resolution of optical excitation and its versatility for arbitrary stimulation patterns the approach also bears potential for auditory research. Here, we review the current state of the art focusing on the emerging concept of optogenetic stimulation of the auditory pathway. Developing optogenetic stimulation for auditory research and future CIs requires efforts toward viral gene transfer to the neurons, design and characterization of appropriate optogenetic actuators, as well as engineering of multichannel optical implants., (Copyright © 2019 Cold Spring Harbor Laboratory Press; all rights reserved.)
- Published
- 2019
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19. Near physiological spectral selectivity of cochlear optogenetics.
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Dieter A, Duque-Afonso CJ, Rankovic V, Jeschke M, and Moser T
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- Animals, Cochlea surgery, Cochlear Implantation, Cochlear Implants, Female, Gerbillinae, Inferior Colliculi cytology, Inferior Colliculi physiology, Male, Neurons cytology, Neurons physiology, Spiral Ganglion physiology, Spiral Ganglion surgery, Cochlea physiology, Optogenetics methods
- Abstract
Cochlear implants (CIs) electrically stimulate spiral ganglion neurons (SGNs) and partially restore hearing to half a million CI users. However, wide current spread from intracochlear electrodes limits spatial selectivity (i.e. spectral resolution) of electrical CIs. Optogenetic stimulation might become an alternative, since light can be confined in space, promising artificial sound encoding with increased spectral selectivity. Here we compare spectral selectivity of optogenetic, electric, and acoustic stimulation by multi-channel recordings in the inferior colliculus (IC) of gerbils. When projecting light onto tonotopically distinct SGNs, we observe corresponding tonotopically ordered IC activity. An activity-based comparison reveals that spectral selectivity of optogenetic stimulation is indistinguishable from acoustic stimulation for modest intensities. Moreover, optogenetic stimulation outperforms bipolar electric stimulation at medium and high intensities and monopolar electric stimulation at all intensities. In conclusion, we demonstrate better spectral selectivity of optogenetic over electric SGN stimulation, suggesting the potential for improved hearing restoration by optical CIs.
- Published
- 2019
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20. Ultrafast optogenetic stimulation of the auditory pathway by targeting-optimized Chronos.
- Author
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Keppeler D, Merino RM, Lopez de la Morena D, Bali B, Huet AT, Gehrt A, Wrobel C, Subramanian S, Dombrowski T, Wolf F, Rankovic V, Neef A, and Moser T
- Subjects
- Animals, Brain Stem metabolism, Channelrhodopsins genetics, Evoked Potentials, Auditory, HEK293 Cells, Humans, Mice, Rats, Rats, Wistar, Channelrhodopsins biosynthesis, Dependovirus, Gene Expression, Neurons metabolism, Optogenetics, Spiral Ganglion metabolism, Transduction, Genetic
- Abstract
Optogenetic tools, providing non-invasive control over selected cells, have the potential to revolutionize sensory prostheses for humans. Optogenetic stimulation of spiral ganglion neurons (SGNs) in the ear provides a future alternative to electrical stimulation used in cochlear implants. However, most channelrhodopsins do not support the high temporal fidelity pertinent to auditory coding because they require milliseconds to close after light-off. Here, we biophysically characterized the fast channelrhodopsin Chronos and revealed a deactivation time constant of less than a millisecond at body temperature. In order to enhance neural expression, we improved its trafficking to the plasma membrane (Chronos-ES/TS). Following efficient transduction of SGNs using early postnatal injection of the adeno-associated virus AAV-PHPB into the mouse cochlea, fiber-based optical stimulation elicited optical auditory brainstem responses (oABR) with minimal latencies of 1 ms, thresholds of 5 μJ and 100 μs per pulse, and sizable amplitudes even at 1,000 Hz of stimulation. Recordings from single SGNs demonstrated good temporal precision of light-evoked spiking. In conclusion, efficient virus-mediated expression of targeting-optimized Chronos-ES/TS achieves ultrafast optogenetic control of neurons., (© 2018 The Authors.)
- Published
- 2018
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21. High frequency neural spiking and auditory signaling by ultrafast red-shifted optogenetics.
- Author
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Mager T, Lopez de la Morena D, Senn V, Schlotte J, D Errico A, Feldbauer K, Wrobel C, Jung S, Bodensiek K, Rankovic V, Browne L, Huet A, Jüttner J, Wood PG, Letzkus JJ, Moser T, and Bamberg E
- Subjects
- Animals, Calcium metabolism, Cell Line, Tumor, Cells, Cultured, Hearing physiology, Humans, Mice, Mutation, Patch-Clamp Techniques, Permeability, Rats, Rats, Sprague-Dawley, Signal Transduction, Xenopus laevis, Action Potentials, Auditory Pathways physiology, Neurons physiology, Optogenetics methods
- Abstract
Optogenetics revolutionizes basic research in neuroscience and cell biology and bears potential for medical applications. We develop mutants leading to a unifying concept for the construction of various channelrhodopsins with fast closing kinetics. Due to different absorption maxima these channelrhodopsins allow fast neural photoactivation over the whole range of the visible spectrum. We focus our functional analysis on the fast-switching, red light-activated Chrimson variants, because red light has lower light scattering and marginal phototoxicity in tissues. We show paradigmatically for neurons of the cerebral cortex and the auditory nerve that the fast Chrimson mutants enable neural stimulation with firing frequencies of several hundred Hz. They drive spiking at high rates and temporal fidelity with low thresholds for stimulus intensity and duration. Optical cochlear implants restore auditory nerve activity in deaf mice. This demonstrates that the mutants facilitate neuroscience research and future medical applications such as hearing restoration.
- Published
- 2018
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22. A combination of NMDA and AMPA receptor antagonists retards granule cell dispersion and epileptogenesis in a model of acquired epilepsy.
- Author
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Schidlitzki A, Twele F, Klee R, Waltl I, Römermann K, Bröer S, Meller S, Gerhauser I, Rankovic V, Li D, Brandt C, Bankstahl M, Töllner K, and Löscher W
- Subjects
- Animals, Anticonvulsants pharmacology, Dentate Gyrus cytology, Dentate Gyrus drug effects, Dentate Gyrus pathology, Disease Models, Animal, Drug Administration Schedule, Drug Therapy, Combination, Electroencephalography, Epilepsy chemically induced, Epilepsy diagnosis, Epilepsy pathology, Humans, Kainic Acid toxicity, Male, Mice, Neurons drug effects, Neurons pathology, Piperidines pharmacology, Piperidines therapeutic use, Quinoxalines pharmacology, Quinoxalines therapeutic use, Time Factors, Treatment Outcome, Anticonvulsants therapeutic use, Epilepsy drug therapy, Receptors, AMPA antagonists & inhibitors, Receptors, N-Methyl-D-Aspartate antagonists & inhibitors
- Abstract
Epilepsy may arise following acute brain insults, but no treatments exist that prevent epilepsy in patients at risk. Here we examined whether a combination of two glutamate receptor antagonists, NBQX and ifenprodil, acting at different receptor subtypes, exerts antiepileptogenic effects in the intrahippocampal kainate mouse model of epilepsy. These drugs were administered over 5 days following kainate. Spontaneous seizures were recorded by video/EEG at different intervals up to 3 months. Initial trials showed that drug treatment during the latent period led to higher mortality than treatment after onset of epilepsy, and further, that combined therapy with both drugs caused higher mortality at doses that appear safe when used singly. We therefore refined the combined-drug protocol, using lower doses. Two weeks after kainate, significantly less mice of the NBQX/ifenprodil group exhibited electroclinical seizures compared to vehicle controls, but this effect was lost at subsequent weeks. The disease modifying effect of the treatment was associated with a transient prevention of granule cell dispersion and less neuronal degeneration in the dentate hilus. These data substantiate the involvement of altered glutamatergic transmission in the early phase of epileptogenesis. Longer treatment with NBQX and ifenprodil may shed further light on the apparent temporal relationship between dentate gyrus reorganization and development of spontaneous seizures.
- Published
- 2017
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23. Zinc deficiency dysregulates the synaptic ProSAP/Shank scaffold and might contribute to autism spectrum disorders.
- Author
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Grabrucker S, Jannetti L, Eckert M, Gaub S, Chhabra R, Pfaender S, Mangus K, Reddy PP, Rankovic V, Schmeisser MJ, Kreutz MR, Ehret G, Boeckers TM, and Grabrucker AM
- Subjects
- Animals, Attention Deficit Disorder with Hyperactivity physiopathology, Behavior, Animal physiology, Blotting, Western, Cells, Cultured, Child Development Disorders, Pervasive physiopathology, Chromosome Deletion, Chromosome Disorders metabolism, Chromosome Disorders physiopathology, Chromosomes, Human, Pair 22 metabolism, Female, Hippocampus metabolism, Humans, Immunohistochemistry, Mice, Organ Culture Techniques, Pregnancy, RNA, Small Interfering genetics, Rats, Real-Time Polymerase Chain Reaction, Spectrometry, Fluorescence, Transfection, Vocalization, Animal physiology, Child Development Disorders, Pervasive metabolism, Saposins metabolism, Synapses physiology, Zinc deficiency
- Abstract
Proteins of the ProSAP/Shank family act as major organizing scaffolding elements within the postsynaptic density of excitatory synapses. Deletions, mutations or the downregulation of these molecules has been linked to autism spectrum disorders, the related Phelan McDermid Syndrome or Alzheimer's disease. ProSAP/Shank proteins are targeted to synapses depending on binding to zinc, which is a prerequisite for the assembly of the ProSAP/Shank scaffold. To gain insight into whether the previously reported assembly of ProSAP/Shank through zinc ions provides a crossing point between genetic forms of autism spectrum disorder and zinc deficiency as an environmental risk factor for autism spectrum disorder, we examined the interplay between zinc and ProSAP/Shank in vitro and in vivo using neurobiological approaches. Our data show that low postsynaptic zinc availability affects the activity dependent increase in ProSAP1/Shank2 and ProSAP2/Shank3 levels at the synapse in vitro and that a loss of synaptic ProSAP1/Shank2 and ProSAP2/Shank3 occurs in a mouse model for acute and prenatal zinc deficiency. Zinc-deficient animals displayed abnormalities in behaviour such as over-responsivity and hyperactivity-like behaviour (acute zinc deficiency) and autism spectrum disorder-related behaviour such as impairments in vocalization and social behaviour (prenatal zinc deficiency). Most importantly, a low zinc status seems to be associated with an increased incidence rate of seizures, hypotonia, and attention and hyperactivity issues in patients with Phelan-McDermid syndrome, which is caused by haploinsufficiency of ProSAP2/Shank3. We suggest that the molecular underpinning of prenatal zinc deficiency as a risk factor for autism spectrum disorder may unfold through the deregulation of zinc-binding ProSAP/Shank family members.
- Published
- 2014
- Full Text
- View/download PDF
24. Encoding and transducing the synaptic or extrasynaptic origin of NMDA receptor signals to the nucleus.
- Author
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Karpova A, Mikhaylova M, Bera S, Bär J, Reddy PP, Behnisch T, Rankovic V, Spilker C, Bethge P, Sahin J, Kaushik R, Zuschratter W, Kähne T, Naumann M, Gundelfinger ED, and Kreutz MR
- Subjects
- Animals, Cell Survival, Cells, Cultured, Cyclic AMP Response Element-Binding Protein metabolism, Gene Expression Regulation, Hippocampus cytology, Hippocampus metabolism, Intermediate Filament Proteins metabolism, Long-Term Potentiation, Long-Term Synaptic Depression, MAP Kinase Signaling System, Mice, Neurons cytology, Phosphoric Monoester Hydrolases metabolism, Phosphorylation, Rats, Cell Nucleus metabolism, Nerve Tissue Proteins metabolism, Neurons metabolism, Receptors, N-Methyl-D-Aspartate metabolism, Synapses metabolism
- Abstract
The activation of N-methyl-D-aspartate-receptors (NMDARs) in synapses provides plasticity and cell survival signals, whereas NMDARs residing in the neuronal membrane outside synapses trigger neurodegeneration. At present, it is unclear how these opposing signals are transduced to and discriminated by the nucleus. In this study, we demonstrate that Jacob is a protein messenger that encodes the origin of synaptic versus extrasynaptic NMDAR signals and delivers them to the nucleus. Exclusively synaptic, but not extrasynaptic, NMDAR activation induces phosphorylation of Jacob at serine-180 by ERK1/2. Long-distance trafficking of Jacob from synaptic, but not extrasynaptic, sites depends on ERK activity, and association with fragments of the intermediate filament α-internexin hinders dephosphorylation of the Jacob/ERK complex during nuclear transit. In the nucleus, the phosphorylation state of Jacob determines whether it induces cell death or promotes cell survival and enhances synaptic plasticity., (Copyright © 2013 Elsevier Inc. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
25. Modulation of calcium-dependent inactivation of L-type Ca2+ channels via β-adrenergic signaling in thalamocortical relay neurons.
- Author
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Rankovic V, Landgraf P, Kanyshkova T, Ehling P, Meuth SG, Kreutz MR, Budde T, and Munsch T
- Subjects
- Animals, COS Cells, Cerebral Cortex pathology, Chlorocebus aethiops, Cyclic AMP-Dependent Protein Kinases metabolism, Immunohistochemistry methods, Neurons metabolism, Okadaic Acid pharmacology, Phosphorylation, Rats, Rats, Long-Evans, Signal Transduction, Thalamus pathology, Tissue Distribution, Calcium chemistry, Calcium Channels, L-Type chemistry, Receptors, Adrenergic, beta metabolism
- Abstract
Neuronal high-voltage-activated (HVA) Ca(2+) channels are rapidly inactivated by a mechanism that is termed Ca(2+)-dependent inactivation (CDI). In this study we have shown that β-adrenergic receptor (βAR) stimulation inhibits CDI in rat thalamocortical (TC) relay neurons. This effect can be blocked by inhibition of cAMP-dependent protein kinase (PKA) with a cell-permeable inhibitor (myristoylated protein kinase inhibitor-(14-22)-amide) or A-kinase anchor protein (AKAP) St-Ht31 inhibitory peptide, suggesting a critical role of these molecules downstream of the receptor. Moreover, inhibition of protein phosphatases (PP) with okadaic acid revealed the involvement of phosphorylation events in modulation of CDI after βAR stimulation. Double fluorescence immunocytochemistry and pull down experiments further support the idea that modulation of CDI in TC neurons via βAR stimulation requires a protein complex consisting of Ca(V)1.2, PKA and proteins from the AKAP family. All together our data suggest that AKAPs mediate targeting of PKA to L-type Ca(2+) channels allowing their phosphorylation and thereby modulation of CDI.
- Published
- 2011
- Full Text
- View/download PDF
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