scholarly journals Endocranial anatomy of the ceratopsid dinosaur Triceratops and interpretations of sensory and motor function

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9888 ◽  
Author(s):  
Rina Sakagami ◽  
Soichiro Kawabe
Keyword(s):  
Olfactory Bulb ◽  
Inner Ear ◽  
Sensory Input ◽  
Three Dimensional ◽  
Semicircular Canals ◽  
Lateral Semicircular Canal ◽  
Linear Measurements ◽  
Low Frequencies ◽  
Effective Angle ◽  
Ceratopsian Dinosaurs

Triceratops is one of the well-known Cretaceous ceratopsian dinosaurs. The ecology of Triceratops has been controversial because of its unique morphological features. However, arguments based on brain and inner ear structures have been scarce. In this study, two braincases (FPDM-V-9677 and FPDM-V-9775) were analyzed with computed tomography to generate three-dimensional virtual renderings of the endocasts of the cranial cavities and bony labyrinths. Quantitative analysis, including comparison of linear measurements of the degree of development of the olfactory bulb and inner ear, was performed on these virtual endocasts to acquire detailed neuroanatomical information. When compared with other dinosaurs, the olfactory bulb of Triceratops is relatively small, indicating that Triceratops had a reduced acuity in sense of smell. The lateral semicircular canal reveals that the basicranial axis of Triceratops is approximately 45° to the ground, which is an effective angle to display their horns as well as frill, and to graze. The semicircular canals of Triceratops are relatively smaller than those of primitive ceratopsians, such as Psittacosaurus and Protoceratops, suggesting that sensory input for the reflexive stabilization of gaze and posture of Triceratops was less developed than that of primitive ceratopsians. The cochlear length of Triceratops is relatively short when compared with other dinosaurs. Because cochlear length correlates with hearing frequency, Triceratops was likely adapted to hearing low frequencies.

scholarly journals Congenital Inner Ear Abnormalities and COVID-19-Related Ear Infections

2020 ◽  
pp. 014556132096893
Author(s):  
Shivesh Maharaj ◽  
Kapila Hari
Keyword(s):  
Inner Ear ◽  
Acute Infection ◽  
Semicircular Canals ◽  
Risk Of Infection ◽  
Lateral Semicircular Canal ◽  
Congenital Deformities ◽  
Increased Risk ◽  
The Face ◽  
Radiological Abnormality ◽  
Ear Infections

Congenital deformities of the labyrinth of the inner ear may be associated with an increased risk of infection and varying degrees of otologic and vestibular dysfunction. Lateral semicircular canal abnormalities specifically can be associated with either normal hearing or hearing loss (conductive or sensorineural). In our patient, the acute symptoms of vertigo and tinnitus coincided with the diagnosis of COVID-19. It is unlikely that the symptomatology was related to the acute infection, even in the face of the underlying congenital abnormality. It has been shown that there is no correlation between the severity of the radiological abnormality and vestibular symptomatology in patients with isolated abnormalities of the semicircular canals. The abnormality can be asymptomatic.

scholarly journals Automatic Measurement of Inner Ear in Different Mammals1

2020 ◽  
Author(s):  
Yi Du ◽  
Han-dai Qin ◽  
Chen Liu ◽  
Da Liu ◽  
Shuo-long Yuan ◽  
...  
Keyword(s):  
Inner Ear ◽  
Semicircular Canal ◽  
Three Dimensional ◽  
Semicircular Canals ◽  
Automatic Measurement ◽  
The Body ◽  
Human Data ◽  
Dimensional Models ◽  
Three Dimensional Models ◽  
Mini Pigs

AbstractObjectiveThe aim of this research is to develop an accurate and automatic measuring method based on the aid of centerline to construct three dimensional models of inner ear in different mammals and to assess the morphological variations.MethodsThree adult healthy mice, three adult guinea pigs, three adult mini pigs and one left temporal bone of human were included in this research. All 18 animal specimens and the human sample were scanned with the use of Micro-CT. After being segmented, three-dimensional models of the inner ear in different mammals were reconstructed using Mimics. A novel method with the use of centerline was established to estimate the properties of 3D models and to calculate the length, volume and angle parameters automatically.ResultsMorphological models of inner ears in different mammals have been built, which describe detailed shape of cochlear, vestibule, semicircular canals and common crus. Mean value of lengths and volumes of the cochlear, lateral semicircular canal, superior semicircular canal and posterior semicircular canal, tended to increase with the body size of the mammals, showed the proximity to the human data in mini pig. The angles between the semicircular canal planes showed differences between mammals. The mean values of semicircular canals of mice and mini pigs closely resembled to human data in numerical assessment.ConclusionThe automatic measurement of the inner ear based on centerline builds an effective way to assess lengths, volumes and angles of three-dimensional structures. This study provides a theoretical basis for mechanical analysis of inner ear in different mammals and proves the similarity between mini pig and human.

Bilateral, isolated, lateral semicircular canal malformation without hearing loss

2008 ◽  
Vol 122 (8) ◽  
pp. 858-860 ◽  
Author(s):  
I Dallan ◽  
S Berrettini ◽  
E Neri ◽  
A P Casani
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Semicircular Canal ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
Lateral Semicircular Canal ◽  
Normal Limits ◽  
Dimensional Reconstruction ◽  
Ear Malformations ◽  
Molecular Aspects

AbstractHypothesis:Inner-ear malformations are frequently found in patients with sensorineural hearing loss. However, isolated anomalies of the vestibular part of the inner ear are seldom described, and for this reason their impact on balance is poorly understood.Care report:We present the case of a 38-year-old Caucasian man with recurrent vestibular complaints, with a sensation of linear tilting, but no hearing impairment. Clinical and neuro-otological examinations showed peripheral involvement of the vestibular system, while audiological investigation was within normal limits. High-resolution magnetic resonance imaging of the inner ear, with three-dimensional reconstruction, demonstrated isolated vestibular anomalies involving both the lateral semicircular canal and the utricle.Conclusions:Bearing in mind this case, we speculate that isolated vestibular malformation may not be as rare as previously thought, and should be investigated with the aid of sophisticated imaging techniques. A review of the relative literature, focussing attention on the molecular aspects, is also reported.

Addition of the BMP4 antagonist, noggin, disrupts avian inner ear development

Development ◽  
2000 ◽  
Vol 127 (1) ◽  
pp. 45-54 ◽  
Author(s):  
L.M. Gerlach ◽  
M.R. Hutson ◽  
J.A. Germiller ◽  
D. Nguyen-Luu ◽  
J.C. Victor ◽  
...  
Keyword(s):  
Inner Ear ◽  
Three Dimensional ◽  
Semicircular Canals ◽  
Limb Bud ◽  
Dimensional Structure ◽  
Spatiotemporal Pattern ◽  
Morphological Development ◽  
Agarose Beads ◽  
Morphogenetic Protein ◽  
Bmp4 Expression

Bone morphogenetic protein 4 (BMP4) is known to regulate dorsoventral patterning, limb bud formation and axis specification in many organisms, including the chicken. In the chick developing inner ear, BMP4 expression becomes localized in two cell clusters at the anterior and posterior edges of the otic epithelium beginning at stage 16/17 and is expressed in presumptive sensory tissue at later stages. This restricted spatiotemporal pattern of expression occurs just prior to the otocyst's transition to a more complex three-dimensional structure. To further analyze the role of BMP4 in avian otic morphogenesis, cells expressing BMP4 or its antagonist, noggin, were grown on agarose beads and implanted into the periotic mesenchyme surrounding the chick otocyst. Although the BMP4-producing cells had no effect on the mature inner ear structure when implanted alone, noggin-producing cells implanted adjacent to the BMP4 cell foci prevented normal semicircular canal development. Beads implanted at the anterior BMP4 focus eliminated the anterior and/or the horizontal canals. Noggin cells implanted at the posterior focus eliminated the posterior canal. Canal loss was prevented by co-implantation of BMP4 cell beads next to noggin beads. An antibody to the chick hair cell antigen (HCA) was used to examine sensory cell distribution, which was abnormal only in the affected tissues of noggin-exposed inner ears. These data suggest a role for BMP4 in the accurate and complete morphological development of the semicircular canals.

Involvement of programmed cell death in morphogenesis of the vertebrate inner ear

Development ◽  
1997 ◽  
Vol 124 (12) ◽  
pp. 2451-2461 ◽  
Author(s):  
D.M. Fekete ◽  
S.A. Homburger ◽  
M.T. Waring ◽  
A.E. Riedl ◽  
L.F. Garcia
Keyword(s):  
Cell Death ◽  
Epithelial Cells ◽  
Programmed Cell Death ◽  
Inner Ear ◽  
Three Dimensional ◽  
Semicircular Canals ◽  
Otic Vesicle ◽  
New Evidence

An outstanding challenge in developmental biology is to reveal the mechanisms underlying the morphogenesis of complex organs. A striking example is the developing inner ear of the vertebrate, which acquires a precise three-dimensional arrangement of its constituent epithelial cells to form three semicircular canals, a central vestibule and a coiled cochlea (in mammals). In generating a semicircular canal, epithelial cells seem to ‘disappear’ from the center of each canal. This phenomenon has been variously explained as (i) transdifferentiation of epithelium into mesenchyme, (ii) absorption of cells into the expanding canal or (iii) programmed cell death. In this study, an in situ DNA-end labeling technique (the TUNEL protocol) was used to map regions of cell death during inner ear morphogenesis in the chicken embryo from embryonic days 3.5-10. Regions of cell death previously identified in vertebrate ears have been confirmed, including the ventromedial otic vesicle, the base of the endolymphatic duct and the fusion plates of the semicircular canals. New regions of cell death are also described in and around the sensory organs. Reducing normal death using retrovirus-mediated overexpression of human bcl-2 causes abnormalities in ear morphogenesis: hollowing of the center of each canal is either delayed or fails entirely. These data provide new evidence to explain the role of cell death in morphogenesis of the semicircular canals.

scholarly journals Assessing Inner Ear Volumetric Measurements by Using Three-Dimensional Reconstruction Imaging of High-Resolution Cone-Beam Computed Tomography

2020 ◽  
Vol 2 (11) ◽  
pp. 2178-2184
Author(s):  
Jan Hiller ◽  
Nour-Eldin Abdelrehim Nour-Eldin ◽  
Tatjana Gruber-Rouh ◽  
Iris Burck ◽  
Marc Harth ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Inner Ear ◽  
Three Dimensional ◽  
Semicircular Canals ◽  
Cone Beam ◽  
Three Dimensional Reconstruction ◽  
Clinical Diagnoses ◽  
Dimensional Reconstruction ◽  
Volumetric Measurements

AbstractThe aim of the study was to obtain volumetric data of the components of the inner ear using three-dimensional reconstruction of high-resolution cone-beam computed tomography (CBCT) images. Two hundred three CBCT image series of the temporal bone from 118 anatomically normal patients (55 women and 63 men; mean age: 49.4 ± 20.4 years) with different suspected disorders were included in this study. Normative volumetric measurements of the inner ear, the cochlea, the semicircular canals (SSC), and the vestibule were determined using a semi-automated reconstruction method of the Workstation. Volumetric measurements were successfully completed in all 118 patients. Mean inner ear, cochlear, and vestibule volumes were statistically significantly larger in males than in females on both sides (p < 0.001). Regarding the semicircular canals, no statistically significant (p = 0.053) volume difference was found. The difference between the volumes on both sides was not significant. No correlation between the patient’s age and the volume of the compartments was seen (p > 0.05). There was no significant difference between mean bony inner ear volumes when the clinical diagnoses were compared (p > 0.05 for all clinical diagnoses and volumes). Our study concluded that three-dimensional reconstruction and assessment of the volumetric measurements of the inner ear can be obtained using high-resolution CBCT imaging.

scholarly journals Gene therapy via canalostomy approach preserves auditory and vestibular functions in a mouse model of Jervell and Lange-Nielsen syndrome type 2

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xuewen Wu ◽  
Li Zhang ◽  
Yihui Li ◽  
Wenjuan Zhang ◽  
Jianjun Wang ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Mouse Model ◽  
Inner Ear ◽  
Viral Vectors ◽  
Survival Rates ◽  
Semicircular Canals ◽  
Dependent Manner ◽  
Syndrome Type ◽  
Dose Dependent

AbstractMutations in voltage-gated potassium channel KCNE1 cause Jervell and Lange-Nielsen syndrome type 2 (JLNS2), resulting in congenital deafness and vestibular dysfunction. We conducted gene therapy by injecting viral vectors using the canalostomy approach in Kcne1−/− mice to treat both the hearing and vestibular symptoms. Results showed early treatment prevented collapse of the Reissner’s membrane and vestibular wall, retained the normal size of the semicircular canals, and prevented the degeneration of inner ear cells. In a dose-dependent manner, the treatment preserved auditory (16 out of 20 mice) and vestibular (20/20) functions in mice treated with the high-dosage for at least five months. In the low-dosage group, a subgroup of mice (13/20) showed improvements only in the vestibular functions. Results supported that highly efficient transduction is one of the key factors for achieving the efficacy and maintaining the long-term therapeutic effect. Secondary outcomes of treatment included improved birth and litter survival rates. Our results demonstrated that gene therapy via the canalostomy approach, which has been considered to be one of the more feasible delivery methods for human inner ear gene therapy, preserved auditory and vestibular functions in a dose-dependent manner in a mouse model of JLNS2.

scholarly journals Geometric morphometric investigation of craniofacial morphological change in domesticated silver foxes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Timothy M. Kistner ◽  
Katherine D. Zink ◽  
Steven Worthington ◽  
Daniel E. Lieberman
Keyword(s):  
Three Dimensional ◽  
Cranial Base ◽  
Craniofacial Morphology ◽  
Wild Populations ◽  
Linear Measurements ◽  
Skeletal Morphology ◽  
Geometric Morphometric ◽  
Domestication Syndrome ◽  
Morphometric Investigation ◽  
Unselected Population

AbstractTo test the effects of domestication on craniofacial skeletal morphology, we used three-dimensional geometric morphometrics (GM) along with linear and endocranial measurements to compare selected (domesticated) and unselected foxes from the Russian Farm-Fox Experiment to wild foxes from the progenitor population from which the farmed foxes are derived. Contrary to previous findings, we find that domesticated and unselected foxes show minimal differences in craniofacial shape and size compared to the more substantial differences between the wild foxes and both populations of farmed foxes. GM analyses and linear measurements demonstrate that wild foxes differ from farmed foxes largely in terms of less cranial base flexion, relatively expanded cranial vaults, and increased endocranial volumes. These results challenge the assumption that the unselected population of foxes kept as part of the Russian Farm-Fox experiment are an appropriate proxy for ‘wild’ foxes in terms of craniofacial morphology and highlight the need to include wild populations in further studies of domestication syndrome to disentangle the phenotypic effects of multiple selection pressures. These findings also suggest that marked increases in docility cannot be reliably diagnosed from shape differences in craniofacial skeletal morphology.

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