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Orekhova K, Selmanovic E, De Gasperi R, Gama Sosa MA, Wicinski B, Maloney B, Seifert A, Alipour A, Balchandani P, Gerussi T, Graïc JM, Centelleghe C, Di Guardo G, Mazzariol S, Hof PR. Multimodal Assessment of Bottlenose Dolphin Auditory Nuclei Using 7-Tesla MRI, Immunohistochemistry and Stereology. Vet Sci 2022; 9:vetsci9120692. [PMID: 36548853 PMCID: PMC9781543 DOI: 10.3390/vetsci9120692] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/05/2022] [Accepted: 12/09/2022] [Indexed: 12/14/2022] Open
Abstract
The importance of assessing neurochemical processes in the cetacean brain as a tool for monitoring their cognitive health and to indirectly model human neurodegenerative conditions is increasingly evident, although available data are largely semiquantitative. High-resolution MRI for post-mortem brains and stereology allow for quantitative assessments of the cetacean brain. In this study, we scanned two brains of bottlenose dolphins in a 7-Tesla (7T) MR scanner and assessed the connectivity of the inferior colliculi and ventral cochlear nuclei using diffusion tensor imaging (DTI). Serial thick sections were investigated stereologically in one of the dolphins to generate rigorous quantitative estimates of identifiable cell types according to their morphology and expression of molecular markers, yielding reliable cell counts with most coefficients of error <10%. Fibronectin immunoreactivity in the dolphin resembled the pattern in a human chronic traumatic encephalopathy brain, suggesting that neurochemical compensation for insults such as hypoxia may constitute a noxious response in humans, while being physiological in dolphins. These data contribute to a growing body of knowledge on the morphological and neurochemical properties of the dolphin brain and highlight a stereological and neuroimaging workflow that may enable quantitative and translational assessment of pathological processes in the dolphin brain in the future.
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Affiliation(s)
- Ksenia Orekhova
- Department of Comparative Biomedicine and Food Science, University of Padova AGRIPOLIS, Viale dell’Università 16, 35020 Legnaro, Italy
- Correspondence:
| | - Enna Selmanovic
- Nash Family Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Rita De Gasperi
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Research and Development Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, New York, NY 10468, USA
| | - Miguel A. Gama Sosa
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- General Medical Research Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, New York, NY 10468, USA
| | - Bridget Wicinski
- Nash Family Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Brigid Maloney
- Laboratory of Neurogenetics of Vocal Learning, Rockefeller University, New York, NY 10065, USA
| | - Alan Seifert
- Department of Radiology, BioMedical Engineering and Imaging Institute (BMEII), Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Akbar Alipour
- Department of Radiology, BioMedical Engineering and Imaging Institute (BMEII), Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Priti Balchandani
- Department of Radiology, BioMedical Engineering and Imaging Institute (BMEII), Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Tommaso Gerussi
- Department of Comparative Biomedicine and Food Science, University of Padova AGRIPOLIS, Viale dell’Università 16, 35020 Legnaro, Italy
| | - Jean-Marie Graïc
- Department of Comparative Biomedicine and Food Science, University of Padova AGRIPOLIS, Viale dell’Università 16, 35020 Legnaro, Italy
| | - Cinzia Centelleghe
- Department of Comparative Biomedicine and Food Science, University of Padova AGRIPOLIS, Viale dell’Università 16, 35020 Legnaro, Italy
| | - Giovanni Di Guardo
- Faculty of Veterinary Medicine, University of Teramo, 64100 Teramo, Italy
| | - Sandro Mazzariol
- Department of Comparative Biomedicine and Food Science, University of Padova AGRIPOLIS, Viale dell’Università 16, 35020 Legnaro, Italy
| | - Patrick R. Hof
- Nash Family Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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Eggermont JJ. Ups and Downs in 75 Years of Electrocochleography. Front Syst Neurosci 2017; 11:2. [PMID: 28174524 PMCID: PMC5259695 DOI: 10.3389/fnsys.2017.00002] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 01/11/2017] [Indexed: 11/13/2022] Open
Abstract
Before 1964, electrocochleography (ECochG) was a surgical procedure carried out in the operating theatre. Currently, the newest application is also an intra-operative one, often carried out in conjunction with cochlear implant surgery. Starting in 1967, the recording methods became either minimal- or not-invasive, i.e., trans-tympanic (TT) or extra tympanic (ET), and included extensive studies of the arguments pro and con. I will review several valuable applications of ECochG, from a historical point of view, but covering all 75 years if applicable. The main topics will be: (1) comparing human and animal cochlear electrophysiology; (2) the use in objective audiometry involving tone pip stimulation-currently mostly pre cochlear implantation but otherwise replaced by auditory brainstem response (ABR) recordings; (3) attempts to diagnose Ménière's disease and the role of the summating potential (SP); (4) early use in diagnosing vestibular schwannomas-now taken over by ABR screening and MRI confirmation; (5) relating human electrophysiology to the effects of genes as in auditory neuropathy; and (6) intracochlear recording using the cochlear implant electrodes. The last two applications are the most recently added ones. The "historical aspects" of this review article will highlight the founding years prior to 1980 when relevant. A survey of articles on Pubmed shows several ups and downs in the clinical interest as reflected in the publication counts over the last 75 years.
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Affiliation(s)
- Jos J. Eggermont
- Department of Psychology, University of CalgaryCalgary, AB, Canada
- Department of Physiology and Pharmacology, University of CalgaryCalgary, AB, Canada
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Godfrey DA, Lee AC, Hamilton WD, Benjamin LC, Vishwanath S, Simo H, Godfrey LM, Mustapha AIAA, Heffner RS. Volumes of cochlear nucleus regions in rodents. Hear Res 2016; 339:161-74. [PMID: 27435005 PMCID: PMC5835392 DOI: 10.1016/j.heares.2016.07.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 07/15/2016] [Indexed: 01/31/2023]
Abstract
The cochlear nucleus receives all the coded information about sound from the cochlea and is the source of auditory information for the rest of the central auditory system. As such, it is a critical auditory nucleus. The sizes of the cochlear nucleus as a whole and its three major subdivisions - anteroventral cochlear nucleus (AVCN), posteroventral cochlear nucleus (PVCN), and dorsal cochlear nucleus (DCN) - have been measured in a large number of mammals, but measurements of its subregions at a more detailed level for a variety of species have not previously been made. Size measurements are reported here for the summed granular regions, DCN layers, AVCN, PVCN, and interstitial nucleus in 15 different rodent species, as well as a lagomorph, carnivore, and small primate. This further refinement of measurements is important because the granular regions and superficial layers of the DCN appear to have some different functions than the other cochlear nucleus regions. Except for DCN layers in the mountain beaver, all regions were clearly identifiable in all the animals studied. Relative regional size differences among most of the rodents, and even the 3 non-rodents, were not large and did not show a consistent relation to their wide range of lifestyles and hearing parameters. However, the mountain beaver, and to a lesser extent the pocket gopher, two rodents that live in tunnel systems, had relative sizes of summed granular regions and DCN molecular layer distinctly larger than those of the other mammals. Among all the mammals studied, there was a high correlation between the size per body weight of summed granular regions and that of the DCN molecular layer, consistent with other evidence for a close relationship between granule cells and superficial DCN neurons.
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Affiliation(s)
- Donald A Godfrey
- Department of Neurology, University of Toledo, United States; Division of Otolaryngology and Dentistry, Department of Surgery, University of Toledo, United States.
| | - Augustine C Lee
- Department of Neurology, University of Toledo, United States; Division of Otolaryngology and Dentistry, Department of Surgery, University of Toledo, United States
| | - Walter D Hamilton
- Department of Neurology, University of Toledo, United States; Division of Otolaryngology and Dentistry, Department of Surgery, University of Toledo, United States
| | - Louis C Benjamin
- Department of Neurology, University of Toledo, United States; Division of Otolaryngology and Dentistry, Department of Surgery, University of Toledo, United States
| | - Shilpa Vishwanath
- Department of Neurology, University of Toledo, United States; Division of Otolaryngology and Dentistry, Department of Surgery, University of Toledo, United States
| | - Hermann Simo
- Department of Medicine, University of Toledo, United States
| | - Lynn M Godfrey
- Department of Neurology, University of Toledo, United States; Division of Otolaryngology and Dentistry, Department of Surgery, University of Toledo, United States
| | - Abdurrahman I A A Mustapha
- Department of Neurology, University of Toledo, United States; Division of Otolaryngology and Dentistry, Department of Surgery, University of Toledo, United States
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Malkemper EP, Oelschläger HHA, Huggenberger S. The dolphin cochlear nucleus: topography, histology and functional implications. J Morphol 2011; 273:173-85. [PMID: 21987441 DOI: 10.1002/jmor.11013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 07/08/2011] [Accepted: 08/03/2011] [Indexed: 11/12/2022]
Abstract
Despite the outstanding auditory capabilities of dolphins, there is only limited information available on the cytology of the auditory brain stem nuclei in these animals. Here, we investigated the cochlear nuclei (CN) of five brains of common dolphins (Delphinus delphis) and La Plata dolphins (Pontoporia blainvillei) using cell and fiber stain microslide series representing the three main anatomical planes. In general, the CN in dolphins comprise the same set of subnuclei as in other mammals. However, the volume ratio of the dorsal cochlear nucleus (DCN) in relation to the ventral cochlear nucleus (VCN) of dolphins represents a minimum among the mammals examined so far. Because, for example, in cats the DCN is necessary for reflexive orientation of the head and pinnae towards a sound source, the massive restrictions in head movability in dolphins and the absence of outer ears may be correlated with the reduction of the DCN. Moreover, the same set of main neuron types were found in the dolphin CN as in other mammals, including octopus and multipolar cells. Because the latter two types of neurons are thought to be involved in the recognition of complex sounds, including speech, we suggest that, in dolphins, they may be involved in the processing of their communication signals. Comparison of the toothed whale species studied here revealed that large spherical cells were present in the La Plata dolphin but absent in the common dolphin. These neurons are known to be engaged in the processing of low-frequency sounds in terrestrial mammals. Accordingly, in the common dolphin, the absence of large spherical cells seems to be correlated with a shift of its auditory spectrum into the high-frequency range above 20 kHz. The existence of large spherical cells in the VCN of the La Plata dolphin, however, is enigmatic asthis species uses frequencies around 130 kHz.
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Affiliation(s)
- E P Malkemper
- Department of Anatomy III (Dr. Senckenbergische Anatomie), Johann Wolfgang Goethe University Frankfurt am Main, 60590 Frankfurt am Main, Germany
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Ruhrig S, Hummel G, Goller H. [Development and cell differentiation of the vestibulocochlear nuclei in cattle]. Anat Histol Embryol 1994; 23:1-11. [PMID: 7943752 DOI: 10.1111/j.1439-0264.1994.tb00236.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Based upon light- and electron microscopic examinations (50 embryos ranging from 1 to 53 cm crown-rump-length, CRL) the origin of the nuclei of the cranial nerve VIII is described with special regard to neurogenesis. The ventricular matrix lateral to the sulcus limitans represents the alar plate with its sensory areas. Up to 2.7 cm CRL migrating neurons from the vestibular nuclei can be detected, the bigger neuronal elements of which are the early formed lateral vestibular nucleus. From 6.7 cm CRL onward all nuclear groups of the vestibular nerve can be identified. At 1 cm CRL the recess plate represents the primordium of the cochlear nuclear complex. Identification of the definitive nuclei is possible at 3.8 cm CRL. Subsequently from 7.6 cm CRL onward the process of lamination can be observed in the dorsal cochlear nucleus. Due to the proceeding maturation the nuclei of the cranial nerve VIII correspond at 53 cm CRL topographically and cytologically to the characteristics of adult animals. Electron microscopic examinations are documenting characteristic features of cytogenesis of sensory neurons (vestibular nucleus) during early embryonic stages (2.5 cm and 3.6 cm CRL). At 2.5 cm CRL the elements exhibiting features of migrating neurons are predominating, whereas at 3.6 cm CRL an increased differentiation is typical for neurons localized in their ultimate position. At this stage synapses can be identified for the first time.
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Affiliation(s)
- S Ruhrig
- Institut für Veterinär-Anatomie, -Histologie und -Embryologie, Justus-Liebig-Universität Giessen
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