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Arthur N. Popper - One of the best experts on this subject based on the ideXlab platform.
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Frequency tuning and intensity coding of sound in the auditory periphery of the lake sturgeon, Acipenser fulvescens
Journal of Experimental Biology, 2010Co-Authors: Michaela Meyer, Richard R. Fay, Arthur N. PopperAbstract:SUMMARY Acipenser fulvescens , the lake sturgeon, belongs to one of the few extant non-teleost ray-finned (bony) fishes. The sturgeons (family Acipenseridae) have a phylogenetic history that dates back about 250 million years. The study reported here is the first investigation of peripheral coding strategies for spectral analysis in the auditory system in a non-teleost bony fish. We used a shaker system to simulate the particle motion component of sound during electrophysiological recordings of isolated single units from the eighth nerve innervating the saccule and Lagena. Background activity and response characteristics of saccular and Lagenar afferents (such as thresholds, response–level functions and temporal firing) resembled the ones found in teleosts. The distribution of best frequencies also resembled data in teleosts (except for Carassius auratus , goldfish) tested with the same stimulation method. The saccule and Lagena in A. fulvescens contain otoconia, in contrast to the solid otoliths found in teleosts, however, this difference in otolith structure did not appear to affect threshold, frequency tuning, intensity- or temporal responses of auditory afferents. In general, the physiological characteristics common to A. fulvescens , teleosts and land vertebrates reflect important functions of the auditory system that may have been conserved throughout the evolution of vertebrates.
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the inner ear of the lungfish protopterus
The Journal of Comparative Neurology, 2004Co-Authors: Christopher Platt, Jørgen Mørup Jørgensen, Arthur N. PopperAbstract:The sensory end organs of the inner ear of the lungfish, Protopterus, were examined using scanning and transmission electron microscopy. The utricle has a structure and hair cell orientation pattern that are typical for vertebrates, although the hair cells are unusually large. There are the typical three semicircular canals extending from the utricle, with the typical hair cell orientations, but the lateral canal sensory crista looks like the “hemicrista” of some amphibians and amniotes, lacking a saddle-shaped flare on one wall of the ampulla. Unlike most vertebrates that have the saccule and Lagena as two separate pouches ventral to the utricle, the lungfish has a single large ventral pouch that contains a single large pasty otoconial mass. This mass covers two hair cell patches, each like a striola with prominent hair cell ciliary bundles, that are presumed to represent saccular and Lagenar maculae. However, these two major sensory patches are not completely separate maculae because they lie within a less densely populated field of smaller hair cells, which forms an extrastriolar region that surrounds and fills the region between the two striolae of higher hair cell density. The more caudal Lagenar striola is a vertically elongated stripe with hair cell orientation vectors facing antiparallel on either side of a midline drawn vertically along the macula, resembling the macula Lagena of some bony fishes but not of tetrapods. The more rostral saccular striola is a curving band with hair cell orientation vectors facing away from its midline, but because this macula curves in three dimensions, the vectors at the rostral end of this striola are oriented mediolaterally, whereas the vectors on the caudal half of this striola are oriented dorsoventrally. The presence of a macula neglecta was confirmed near the posterior canal as a tiny single patch of a few dozen hair cells with all the cell orientations directed caudally. The ciliary bundles on the cells in the striolar-like regions of all of three otolithic organs average over 80 cilia, a number far greater than for any other fish studied to date. The features of the single sacculoLagenar pouch with separate striolar-like regions, the cellular orientation in the otolith organs, and the large cells and ciliary bundles in Protopterus also were observed in specimens of the other extant lungfish genera, Lepidosiren and Neoceratodus.
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Dendritic arbors on the saccule and Lagena in the ear of the goldfish, Carassius auratus.
Hearing Research, 2000Co-Authors: Peggy L Edds-walton, Arthur N. PopperAbstract:Abstract The ear of the goldfish ( Carassius auratus ) contains three otolithic endorgans: the saccule, Lagena, and utricle. The saccule has an auditory function in most teleost fishes for whom data are available, and there is evidence that the Lagena is also an auditory endorgan in the goldfish. This study was conducted to compare the innervation of the saccule and the Lagena to one another and to previously published data from goldfish and other species. We placed cobaltous-lysine in saccular and Lagenar nerves in vivo and permitted uptake over 18–24 h. A total of 59 saccular and 59 Lagenar dendritic arbors were labeled in 10 fishes. Our data indicate that arbors on the saccule and Lagena have similar morphologies, but differ in relative size. Saccular arbors tend to be smaller than Lagenar arbors, with median arbor widths of 50 μm on the saccule and 74 μm on the Lagena. Fiber diameters on the two endorgans are similar. A regional analysis of the saccule indicated that a wide range of arbor sizes are found along the rostral-caudal axis, with larger arbors more common caudally. Our data do not support the presence of two distinct categories of saccular afferents with non-overlapping distributions. Moderate arbor widths (50–99 μm) were most common in all regions of the Lagena. Maximum arbor width and hair cell density do not appear to be correlated with one another on either the saccule or the Lagena. Comparisons with published data from goldfish and oscar revealed similarities and differences that may be attributable to variations in label uptake or transport as well as potential species differences.
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Dendritic arbors on the saccule and Lagena in the ear of the goldfish, Carassius auratus.
Hearing Research, 2000Co-Authors: Peggy L Edds-walton, Arthur N. PopperAbstract:The ear of the goldfish (Carassius auratus) contains three otolithic endorgans: the saccule, Lagena, and utricle. The saccule has an auditory function in most teleost fishes for whom data are available, and there is evidence that the Lagena is also an auditory endorgan in the goldfish. This study was conducted to compare the innervation of the saccule and the Lagena to one another and to previously published data from goldfish and other species. We placed cobaltous-lysine in saccular and Lagenar nerves in vivo and permitted uptake over 18-24 h. A total of 59 saccular and 59 Lagenar dendritic arbors were labeled in 10 fishes. Our data indicate that arbors on the saccule and Lagena have similar morphologies, but differ in relative size. Saccular arbors tend to be smaller than Lagenar arbors, with median arbor widths of 50 micrometer on the saccule and 74 micrometer on the Lagena. Fiber diameters on the two endorgans are similar. A regional analysis of the saccule indicated that a wide range of arbor sizes are found along the rostral-caudal axis, with larger arbors more common caudally. Our data do not support the presence of two distinct categories of saccular afferents with non-overlapping distributions. Moderate arbor widths (50-99 micrometer) were most common in all regions of the Lagena. Maximum arbor width and hair cell density do not appear to be correlated with one another on either the saccule or the Lagena. Comparisons with published data from goldfish and oscar revealed similarities and differences that may be attributable to variations in label uptake or transport as well as potential species differences.
Friedrich Ladich - One of the best experts on this subject based on the ideXlab platform.
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Diversity of Inner Ears in Fishes: Possible Contribution Towards Hearing Improvements and Evolutionary Considerations.
Advances in experimental medicine and biology, 2016Co-Authors: Tanja Schulz-mirbach, Friedrich LadichAbstract:Fishes have evolved the largest diversity of inner ears among vertebrates. While G. Retzius introduced us to the diversity of the gross morphology of fish ears in the late nineteenth century, it was A. N. Popper who unraveled the large variety of the fine structure during the last four decades. Modifications of the basic inner ear structure-consisting of three semicircular canals and their sensory epithelia, the cristae and three otolithic end organs (utricle, saccule, Lagena) including the maculae-mainly relate to the saccule and Lagena and the respective sensory epithelia, the macula sacculi and macula Lagenae. Despite the profound morphological knowledge of inner ears and the morphological variability, the functional significance of this diversity is still largely unknown. The aims of this review are therefore twofold. First it provides an update of the state of the art of inner ear diversity in bony fishes. Second it summarizes and discusses hypotheses on the evolution of this diversity as well as formulates open questions and promising approaches to tackle these issues.
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The role of otolith size in hearing – Insights from cichlid fishes
Frontiers Media S.A., 2015Co-Authors: Tanja Schulz-mirbach, Friedrich Ladich, Martin PlathAbstract:Otolithic end organs in fishes function as accelerometers and are involved in the senses of balance and hearing (e.g. Popper et al. 2005). Otolith mass and shape are likely decisive factors influencing otolith motion, but while it is largely unknown how different shapes affect otolith movement relative to the sensory epithelium (Popper et al. 2005), greater otolith mass is predicted to result in enhanced stimulation of sensory hair cells and improved hearing (Lychakov and Rebane 2005). What few studies exist on this topic, however, yielded contradicting results in that they did or did not find a correlation between increased otolith mass and enhanced hearing (see Kéver et al. 2014). We investigated the relationship between otolith morphology (including 3D-models of otoliths based on high-resolution microCT imaging and otolith weight) and hearing abilities in cichlids while comparing three species (Etroplus maculatus, Hemichromis guttatus, Steatocranus tinanti) with different swimbladder morphology and hearing abilities (Schulz-Mirbach et al. 2014). We predicted Etroplus maculatus—the species that displays the best hearing sensitivities—to possess larger/heavier otoliths. As swimbladder extensions in this species are connected to the Lagena, we further predicted to find heavier Lagenar otoliths. Compared to H. guttatus and S. tinanti, E. maculatus showed the heaviest saccular otoliths, while Lagenar otoliths were significantly thinner and lighter than in the former two species, apparently contradicting the hypothesis that the Lagena and its otolith are primarily involved in improved hearing abilities. Our results support the idea that there is no ‘simple’ relationship between otolith weight, ancilliary auditory structures and hearing abilities. 3D-models of inner ears and otoliths may be ideally suited for future studies modeling complex otolith motion and thus, may provide a better understanding of how otolith morphology contributes to inner ear functions
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A unique swim bladder-inner ear connection in a teleost fish revealed by a combined high-resolution microtomographic and three-dimensional histological study
BMC biology, 2013Co-Authors: Tanja Schulz-mirbach, Martin Heß, Brian D. Metscher, Friedrich LadichAbstract:In most modern bony fishes (teleosts) hearing improvement is often correlated with a close morphological relationship between the swim bladder or other gas-filled cavities and the saccule or more rarely with the utricle. A connection of an accessory hearing structure to the third end organ, the Lagena, has not yet been reported. A recent study in the Asian cichlid Etroplus maculatus provided the first evidence that a swim bladder may come close to the Lagena. Our study was designed to uncover the swim bladder-inner ear relationship in this species. We used a new approach by applying a combination of two high-resolution techniques, namely microtomographic (microCT) imaging and histological serial semithin sectioning, providing the basis for subsequent three-dimensional reconstructions. Prior to the morphological study, we additionally measured auditory evoked potentials at four frequencies (0.5, 1, 2, 3 kHz) to test the hearing abilities of the fish. E. maculatus revealed a complex swim bladder-inner ear connection in which a bipartite swim bladder extension contacts the upper as well as the lower parts of each inner ear, a condition not observed in any other teleost species studied so far. The gas-filled part of the extension is connected to the Lagena via a thin bony lamella and is firmly attached to this bony lamella with connective material. The second part of the extension, a pad-like structure, approaches the posterior and horizontal semicircular canals and a recessus located posterior to the utricle. Our study is the first detailed report of a link between the swim bladder and the Lagena in a teleost species. We suggest that the Lagena has an auditory function in this species because the most intimate contact exists between the swim bladder and this end organ. The specialized attachment of the saccule to the cranial bone and the close proximity of the swim bladder extension to the recessus located posterior to the utricle indicate that the saccule and the utricle also receive parallel inputs from the swim bladder extension. We further showed that a combination of non-destructive microCT imaging with histological analyses on the same specimen provides a powerful tool to decipher and interpret fine structures and to compensate for methodological artifacts.
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a unique swim bladder inner ear connection in a teleost fish revealed by a combined high resolution microtomographic and three dimensional histological study
BMC Biology, 2013Co-Authors: Tanja Schulzmirbach, Brian D. Metscher, Martin Hes, Friedrich LadichAbstract:Background In most modern bony fishes (teleosts) hearing improvement is often correlated with a close morphological relationship between the swim bladder or other gas-filled cavities and the saccule or more rarely with the utricle. A connection of an accessory hearing structure to the third end organ, the Lagena, has not yet been reported. A recent study in the Asian cichlid Etroplus maculatus provided the first evidence that a swim bladder may come close to the Lagena. Our study was designed to uncover the swim bladder-inner ear relationship in this species. We used a new approach by applying a combination of two high-resolution techniques, namely microtomographic (microCT) imaging and histological serial semithin sectioning, providing the basis for subsequent three-dimensional reconstructions. Prior to the morphological study, we additionally measured auditory evoked potentials at four frequencies (0.5, 1, 2, 3 kHz) to test the hearing abilities of the fish.
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Swim bladder and inner ear of P. polleni in (A) lateral and (B) ventral views.
2013Co-Authors: Tanja Schulz-mirbach, Brian D. Metscher, Friedrich LadichAbstract:The swim bladder horn comes close to the Lagena and its otolith, the asteriscus (see also Figure 5). a, anterior; as, asteriscus; asc, anterior semicircular canal; d, dorsal; hsc, horizontal semicircular canal; la, lateral; lap, lapillus; lag, Lagena; psc, posterior semicircular canal; sa, sagitta; sac, sacculus; sb, swim bladder; utr, utricle. Scale bar = 1 mm.
Tanja Schulz-mirbach - One of the best experts on this subject based on the ideXlab platform.
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Diversity of Inner Ears in Fishes: Possible Contribution Towards Hearing Improvements and Evolutionary Considerations.
Advances in experimental medicine and biology, 2016Co-Authors: Tanja Schulz-mirbach, Friedrich LadichAbstract:Fishes have evolved the largest diversity of inner ears among vertebrates. While G. Retzius introduced us to the diversity of the gross morphology of fish ears in the late nineteenth century, it was A. N. Popper who unraveled the large variety of the fine structure during the last four decades. Modifications of the basic inner ear structure-consisting of three semicircular canals and their sensory epithelia, the cristae and three otolithic end organs (utricle, saccule, Lagena) including the maculae-mainly relate to the saccule and Lagena and the respective sensory epithelia, the macula sacculi and macula Lagenae. Despite the profound morphological knowledge of inner ears and the morphological variability, the functional significance of this diversity is still largely unknown. The aims of this review are therefore twofold. First it provides an update of the state of the art of inner ear diversity in bony fishes. Second it summarizes and discusses hypotheses on the evolution of this diversity as well as formulates open questions and promising approaches to tackle these issues.
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The role of otolith size in hearing – Insights from cichlid fishes
Frontiers Media S.A., 2015Co-Authors: Tanja Schulz-mirbach, Friedrich Ladich, Martin PlathAbstract:Otolithic end organs in fishes function as accelerometers and are involved in the senses of balance and hearing (e.g. Popper et al. 2005). Otolith mass and shape are likely decisive factors influencing otolith motion, but while it is largely unknown how different shapes affect otolith movement relative to the sensory epithelium (Popper et al. 2005), greater otolith mass is predicted to result in enhanced stimulation of sensory hair cells and improved hearing (Lychakov and Rebane 2005). What few studies exist on this topic, however, yielded contradicting results in that they did or did not find a correlation between increased otolith mass and enhanced hearing (see Kéver et al. 2014). We investigated the relationship between otolith morphology (including 3D-models of otoliths based on high-resolution microCT imaging and otolith weight) and hearing abilities in cichlids while comparing three species (Etroplus maculatus, Hemichromis guttatus, Steatocranus tinanti) with different swimbladder morphology and hearing abilities (Schulz-Mirbach et al. 2014). We predicted Etroplus maculatus—the species that displays the best hearing sensitivities—to possess larger/heavier otoliths. As swimbladder extensions in this species are connected to the Lagena, we further predicted to find heavier Lagenar otoliths. Compared to H. guttatus and S. tinanti, E. maculatus showed the heaviest saccular otoliths, while Lagenar otoliths were significantly thinner and lighter than in the former two species, apparently contradicting the hypothesis that the Lagena and its otolith are primarily involved in improved hearing abilities. Our results support the idea that there is no ‘simple’ relationship between otolith weight, ancilliary auditory structures and hearing abilities. 3D-models of inner ears and otoliths may be ideally suited for future studies modeling complex otolith motion and thus, may provide a better understanding of how otolith morphology contributes to inner ear functions
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A unique swim bladder-inner ear connection in a teleost fish revealed by a combined high-resolution microtomographic and three-dimensional histological study
BMC biology, 2013Co-Authors: Tanja Schulz-mirbach, Martin Heß, Brian D. Metscher, Friedrich LadichAbstract:In most modern bony fishes (teleosts) hearing improvement is often correlated with a close morphological relationship between the swim bladder or other gas-filled cavities and the saccule or more rarely with the utricle. A connection of an accessory hearing structure to the third end organ, the Lagena, has not yet been reported. A recent study in the Asian cichlid Etroplus maculatus provided the first evidence that a swim bladder may come close to the Lagena. Our study was designed to uncover the swim bladder-inner ear relationship in this species. We used a new approach by applying a combination of two high-resolution techniques, namely microtomographic (microCT) imaging and histological serial semithin sectioning, providing the basis for subsequent three-dimensional reconstructions. Prior to the morphological study, we additionally measured auditory evoked potentials at four frequencies (0.5, 1, 2, 3 kHz) to test the hearing abilities of the fish. E. maculatus revealed a complex swim bladder-inner ear connection in which a bipartite swim bladder extension contacts the upper as well as the lower parts of each inner ear, a condition not observed in any other teleost species studied so far. The gas-filled part of the extension is connected to the Lagena via a thin bony lamella and is firmly attached to this bony lamella with connective material. The second part of the extension, a pad-like structure, approaches the posterior and horizontal semicircular canals and a recessus located posterior to the utricle. Our study is the first detailed report of a link between the swim bladder and the Lagena in a teleost species. We suggest that the Lagena has an auditory function in this species because the most intimate contact exists between the swim bladder and this end organ. The specialized attachment of the saccule to the cranial bone and the close proximity of the swim bladder extension to the recessus located posterior to the utricle indicate that the saccule and the utricle also receive parallel inputs from the swim bladder extension. We further showed that a combination of non-destructive microCT imaging with histological analyses on the same specimen provides a powerful tool to decipher and interpret fine structures and to compensate for methodological artifacts.
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Three-dimensionally reconstructed Lagena and macula Lagenae of cave fish and surface fish from Tampico.
2013Co-Authors: Tanja Schulz-mirbach, Martin Heß, Martin PlathAbstract:(A) and (C), Lagenae in lateral view showing the macula, (the otolithic membrane), the non-sensory epithelium, and the basal lamina in a cave (A; male, SL = 35 mm) and a surface fish (C; female, SL = 52 mm). Note that the Lagena in the surface fish (C) displays a distinct caudo-dorsal ‘edge’ (black arrowhead), while the Lagena of the cave fish lacks this “edge” (A). This feature corresponds to the prominent posterodorsal edge of asterisci from surface fish (see Figure 5D vs. A). (B) and (D) display differences in curvature and especially shape of the macula Lagenae of cave (B) and surface fish (D). The maculae Lagenae are shown in lateral (B1, D1) and dorsal view (B2, D2). BL, basal lamina; d, dorsal; NSE, non-sensory epithelium; la, lateral; OM, otolithic membrane; r, rostral; VIII, part of the eighth cranial nerve innervating the Lagena. Scale bars = 100 µm.
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Swim bladder and inner ear of P. polleni in (A) lateral and (B) ventral views.
2013Co-Authors: Tanja Schulz-mirbach, Brian D. Metscher, Friedrich LadichAbstract:The swim bladder horn comes close to the Lagena and its otolith, the asteriscus (see also Figure 5). a, anterior; as, asteriscus; asc, anterior semicircular canal; d, dorsal; hsc, horizontal semicircular canal; la, lateral; lap, lapillus; lag, Lagena; psc, posterior semicircular canal; sa, sagitta; sac, sacculus; sb, swim bladder; utr, utricle. Scale bar = 1 mm.
Lin Chen - One of the best experts on this subject based on the ideXlab platform.
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Analysis of magnetic elements in otoliths of the macula Lagena in homing pigeons with inductively coupled plasma mass spectrometry.
Neuroscience bulletin, 2009Co-Authors: Ying Zhao, Yi-na Huang, Lv Shi, Lin ChenAbstract:Objective The macula Lagena in birds is located at the apical end of the cochlea and contains many tiny otoliths. The macula Lagena is innervated and has neural projections to the brainstem, but its physiological function is still unclear. It remains disputable that it is because otoliths in the Lagena are rich in elements Fe and Zn that birds can obtain geomagnetic information for homing. To clarify this issue, we carried out a study to determine whether or not otoliths in the Lagena of homing pigeons are richer in magnetic elements than those in the saccule and the utricle. Methods The contents of ferromagnetic elements (Fe, Co, Ni) and other metal elements in Lagenal otoliths of adult homing pigeons were precisely analyzed with inductively coupled plasma mass spectrometry (ICP-MS) of high sensitivity, and then they were compared with those in saccular and utricular otoliths (all the contents were normalized to Ca). Results In adult homing pigeons, the contents of ferromagnetic elements (Fe, Co, Ni) in Lagenal otoliths were less than 0.7% (normalized to Ca element) and were the same order in magnitude as those in saccular and utricular otoliths. The content of Fe in Lagenal otoliths was not significantly different from that in utricular otoliths and was even lower than that in saccular otoliths. The content of Co in Lagenal otoliths was lower than that in saccular otoliths and higher than that in utricular otoliths. The content of Ni in Lagenal otoliths was not significantly different from that in saccular otoliths and was higher than that in utricular otoliths. The contents of other metal elements Na, Mg, K, Al, Mn and Pb in Lagenal otoliths were not significantly different from those in utricular and saccular otoliths. The contents of metal elements Zn, Ba and Cu in Lagenal otoliths were lower than those in saccular otoliths. Conclusion The contents of magnetic elements in Lagenal otoliths of homing pigeons are not much higher than those in utricular and saccular otoliths, which does not support the hypothesis that birds depend on high contents of Fe and Zn in Lagenal otoliths for sensation of geomagnetic information. Similarities in morphology, element ingredient and element content between Lagenal otoliths and utricular otoliths suggest that the two types of otolithic organs may play similar roles in sensing gravitational and acceleration signals.
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Morphometry of otoliths in chicken macula Lagena.
Neuroscience letters, 2006Co-Authors: Chang-xiang Li, Yi-na Huang, Zheng-quan Tang, Ming Gong, Lin ChenAbstract:The macula Lagena located at the apical end of the cochlea in birds is characterized by the presence of numerous otoliths with unclear sensory functions. These otoliths are reported to be similar to those in the vestibular system but their detailed features in morphology are unknown. In the present study, we examined the number, size and shape of otoliths from the macula Lagena in Chinese domestic chickens (Gallus Ling Nan) with a scanning electron microscope for morphometry. For chickens aged 10-15 post-hatch days, the otoliths in each macula Lagena were counted to be 16,055 +/- 4038 (mean +/- S.D., n = 4). The average length and width were 12.98 +/- 3.70 microm and 5.10 +/- 1.48 microm (n = 526 otoliths), respectively. The ratio of length to width for the otolith was 2.58 +/- 0.39 (n = 526 otoliths) and remained relatively constant despite their variations in physical size. Almost all the otoliths were in regular shape and appeared like isolated cylinders with smooth facets at each end, but a few of them (0.025% of 64,221 otoliths screened) were found to be in odd shapes, such as T-shape and cross-shape. The results suggest that otoliths in the macula Lagena and those in the vestibular system of bird's inner ear have similar physical properties and may play a similar role in sensing gravitational and acceleration signals.
Richard D. Rabbitt - One of the best experts on this subject based on the ideXlab platform.
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The quantal component of synaptic transmission from sensory hair cells to the vestibular calyx
Journal of neurophysiology, 2015Co-Authors: Stephen M. Highstein, Mary Anne Mann, Richard D. RabbittAbstract:Spontaneous and stimulus-evoked excitatory postsynaptic currents (EPSCs) were recorded in calyx nerve terminals from the turtle vestibular Lagena to quantify key attributes of quantal transmission ...
