scholarly journals Origins of Inner Ear Sensory Organs Revealed by Fate Map and Time-Lapse Analyses

2001 ◽  
Vol 233 (2) ◽  
pp. 365-379 ◽  
Author(s):  
Sung-Hee Kil ◽  
Andres Collazo
Keyword(s):  
Inner Ear ◽  
Time Lapse ◽  
Fate Map ◽  
Sensory Organs

Axial specification for sensory organs versus non-sensory structures of the chicken inner ear

Development ◽  
1998 ◽  
Vol 125 (1) ◽  
pp. 11-20 ◽  
Author(s):  
D.K. Wu ◽  
F.D. Nunes ◽  
D. Choo
Keyword(s):  
Gene Expression ◽  
Inner Ear ◽  
Expression Patterns ◽  
Growth Factor Receptor ◽  
Gross Anatomy ◽  
Sensory Organ ◽  
Sensory Organs ◽  
Organ Formation ◽  
Sensory Structures ◽  
Axial Specification

A mature inner ear is a complex labyrinth containing multiple sensory organs and nonsensory structures in a fixed configuration. Any perturbation in the structure of the labyrinth will undoubtedly lead to functional deficits. Therefore, it is important to understand molecularly how and when the position of each inner ear component is determined during development. To address this issue, each axis of the otocyst (embryonic day 2.5, E2.5, stage 16–17) was changed systematically at an age when axial information of the inner ear is predicted to be fixed based on gene expression patterns. Transplanted inner ears were analyzed at E4.5 for gene expression of BMP4 (bone morphogenetic protein), SOHo-1 (sensory organ homeobox-1), Otx1 (cognate of Drosophila orthodenticle gene), p75NGFR (nerve growth factor receptor) and Msx1 (muscle segment homeobox), or at E9 for their gross anatomy and sensory organ formation. Our results showed that axial specification in the chick inner ear occurs later than expected and patterning of sensory organs in the inner ear was first specified along the anterior/posterior (A/P) axis, followed by the dorsal/ventral (D/V) axis. Whereas the A/P axis of the sensory organs was fixed at the time of transplantation, the A/P axis for most non-sensory structures was not and was able to be re-specified according to the new axial information from the host. The D/V axis for the inner ear was not fixed at the time of transplantation. The asynchronous specification of the A/P and D/V axes of the chick inner ear suggests that sensory organ formation is a multi-step phenomenon, rather than a single inductive event.

scholarly journals Shaping of inner ear sensory organs through antagonistic interactions between Notch signalling and Lmx1a

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Zoe F Mann ◽  
Héctor Gálvez ◽  
David Pedreno ◽  
Ziqi Chen ◽  
Elena Chrysostomou ◽  
...  
Keyword(s):  
Inner Ear ◽  
Notch Signalling ◽  
Sensory Organ ◽  
Sensory Organs ◽  
Functional Diversification ◽  
Dynamic Nature ◽  
Embryonic Chicken ◽  
Mechanisms Of Formation ◽  
Sensory Patch ◽  
Antagonistic Interactions

The mechanisms of formation of the distinct sensory organs of the inner ear and the non-sensory domains that separate them are still unclear. Here, we show that several sensory patches arise by progressive segregation from a common prosensory domain in the embryonic chicken and mouse otocyst. This process is regulated by mutually antagonistic signals: Notch signalling and Lmx1a. Notch-mediated lateral induction promotes prosensory fate. Some of the early Notch-active cells, however, are normally diverted from this fate and increasing lateral induction produces misshapen or fused sensory organs in the chick. Conversely Lmx1a (or cLmx1b in the chick) allows sensory organ segregation by antagonizing lateral induction and promoting commitment to the non-sensory fate. Our findings highlight the dynamic nature of sensory patch formation and the labile character of the sensory-competent progenitors, which could have facilitated the emergence of new inner ear organs and their functional diversification in the course of evolution.

Growth of the Inner Ear in Organ Culture

1974 ◽  
Vol 83 (14_suppl) ◽  
pp. 1-16 ◽  
Author(s):  
Thomas Van De Water ◽  
R. J. Ruben
Keyword(s):  
Organ Culture ◽  
Inner Ear ◽  
Culture System ◽  
Time Lapse ◽  
Research Tool ◽  
Abnormal Development ◽  
Morphological Development ◽  
Histological Techniques ◽  
Organ Culture System

An organ culture system is presented for the mammalian inner ear. The development of the inner ear is recorded with time lapse cinematography and conventional histological techniques. The system allows for morphological development of differentiation of the neurosensory structures of the inner ear. The use of the organ culture system as a research tool for the understanding of normal and abnormal development of the inner ear is discussed.

Growth of the Inner Ear in Organ Culture

1974 ◽  
Vol 83 (5_suppl) ◽  
pp. 1-16 ◽  
Author(s):  
Thomas Van De Water ◽  
R. J. Ruben
Keyword(s):  
Organ Culture ◽  
Inner Ear ◽  
Culture System ◽  
Time Lapse ◽  
Research Tool ◽  
Abnormal Development ◽  
Morphological Development ◽  
Histological Techniques ◽  
Organ Culture System

An organ culture system is presented for the mammalian inner ear. The development of the inner ear is recorded with time lapse cinematography and conventional histological techniques. The system allows for morphological development of differentiation of the neurosensory structures of the inner ear. The use of the organ culture system as a research tool for the understanding of normal and abnormal development of the inner ear is discussed.

Sensory organ development in cultured striped trumpeter larvae Latris lineata: implications for feeding behaviour

2003 ◽  
Vol 54 (5) ◽  
pp. 669 ◽  
Author(s):  
J. M. Cobcroft ◽  
P. M. Pankhurst
Keyword(s):  
Visual Field ◽  
Inner Ear ◽  
Early Stage ◽  
Larval Growth ◽  
Dark Phase ◽  
Sensory Organs ◽  
Growth And Survival ◽  
Live Feed ◽  
Latris Lineata ◽  
Striped Trumpeter

Teleost larvae are reliant on sensory organs for feeding, in particular for the detection and subsequent capture of prey. The present study describes the development of sensory organs in cultured striped trumpeter larvae, Latris lineata. In addition, a short-term feeding trial was conducted to examine the feeding response of larvae with different senses available; streptomycin sulfate was used to ablate the superficial neuromasts, and testing larvae in the dark prevented visually mediated feeding. Some non-visual senses are available to striped trumpeter larvae from an early age, as indicated by the presence of superficial neuromasts at hatching, and innervated olfactory organs and a developed inner ear from Day 3 post hatching. The neuromasts proliferated on the head and body with increasing larval age, and formation of the lateral line canal had commenced by Day 26 post hatching. Oral taste buds were not present in any of the larvae examined, up to Day 26 post hatching. At hatching, the retina was at an early stage in development, but differentiated rapidly and was presumed functional coincident with the onset of feeding on Day 7 post hatching. The ventro-temporal retina was the last to differentiate, and was distorted by the embryonic fissure, such that larval vision in the forward and upward visual field would be compromised. In contrast, the dorso-temporal retina was the first area to differentiate, and presumptive rod and double-cone development occurred in this area from Days 11 and 16, respectively, indicating that the forward and downward directed visual field is most suited for acute image formation. Larvae on Day 18 post hatching demonstrated increased feeding with an increase in the senses available, with 8 ± 3% of streptomycin-treated larvae feeding in the dark (chemoreception and inner ear mechanoreception only) and 27 ± 5% of untreated larvae feeding in the light (all senses available). It remains to be demonstrated whether there is an advantage to larval growth and survival by providing live feed during the dark phase in culture, facilitating feeding 24 hours per day.

scholarly journals Order and coherence in the fate map of the zebrafish nervous system

Development ◽  
1995 ◽  
Vol 121 (8) ◽  
pp. 2595-2609 ◽  
Author(s):  
K. Woo ◽  
S.E. Fraser
Keyword(s):  
Nervous System ◽  
Neural Development ◽  
Expression Patterns ◽  
Time Lapse ◽  
Cellular Interactions ◽  
Fate Map ◽  
Dorsal Midline ◽  
Vertebrate Model ◽  
The Central Nervous System ◽  
Mutant Phenotypes

The zebrafish is an excellent vertebrate model for the study of the cellular interactions underlying the patterning and the morphogenesis of the nervous system. Here, we report regional fate maps of the zebrafish anterior nervous system at two key stages of neural development: the beginning (6 hours) and the end (10 hours) of gastrulation. Early in gastrulation, we find that the presumptive neurectoderm displays a predictable organization that reflects the future anteroposterior and dorsoventral order of the central nervous system. The precursors of the major brain subdivisions (forebrain, midbrain, hindbrain, neural retina) occupy discernible, though overlapping, domains within the dorsal blastoderm at 6 hours. As gastrulation proceeds, these domains are rearranged such that the basic order of the neural tube is evident at 10 hours. Furthermore, the anteroposterior and dorsoventral order of the progenitors is refined and becomes aligned with the primary axes of the embryo. Time-lapse video microscopy shows that the rearrangement of blastoderm cells during gastrulation is highly ordered. Cells near the dorsal midline at 6 hours, primarily forebrain progenitors, display anterior-directed migration. Cells more laterally positioned, corresponding to midbrain and hindbrain progenitors, converge at the midline prior to anteriorward migration. These results demonstrate a predictable order in the presumptive neurectoderm, suggesting that patterning interactions may be well underway by early gastrulation. The fate maps provide the basis for further analyses of the specification, induction and patterning of the anterior nervous system, as well as for the interpretation of mutant phenotypes and gene-expression patterns.

scholarly journals The Superiority of the Otolith System

2020 ◽  
Vol 25 (Suppl. 1-2) ◽  
pp. 35-41 ◽  
Author(s):  
Angel Ramos de Miguel ◽  
Andrzej Zarowski ◽  
Morgana Sluydts ◽  
Angel Ramos Macias ◽  
Floris L. Wuyts
Keyword(s):  
Inner Ear ◽  
Clinical Evidence ◽  
Sensory Organs ◽  
Otolith Organ ◽  
Vestibular Implant ◽  
Otolith System ◽  
Physical Principles

Background: The peripheral vestibular end organ is considered to consist of semi-circular canals (SCC) for detection of angular accelerations and the otoliths for detection of linear accelerations. However, otoliths being phylogenetically the oldest part of the vestibular sensory organs are involved in detection of all motions. Summary: This study elaborates on this property of the otolith organ, as this concept can be of importance for the currently designed vestibular implant devices. Key Message: The analysis of the evolution of the inner ear and examination of clinical examples shows the robustness of the otolith system and inhibition capacity of the SCC. The otolith system must be considered superior to the SCC system as illustrated by evolution, clinical evidence, and physical principles.

Structural-Functional Correlations in Inner Ear Receptors

1972 ◽  
Vol 30 ◽  
pp. 64-65
Author(s):  
Edwin R. Lewis
Keyword(s):  
Mechanical Properties ◽  
Inner Ear ◽  
Electron Micrographs ◽  
Transmission Electron Micrographs ◽  
Directional Sensitivity ◽  
Sensory Organs ◽  
Receptor Cells ◽  
Transmission Electron ◽  
Transduction Mechanisms

Transduction mechanisms are only partially understood in the sensory organs of the inner ear; and the roles of the receptor cells themselves with their magnificent elaborations of microvilli (stereocilia) and true cilia (kinocilia) are almost completely unknown. Certain clues are available, however. For example, scanning and transmission electron micrographs strongly suggest that the directional sensitivity known to be present in these receptors is imparted to them by the mechanical properties of the anisotropic array of stereocilia. Another clue may lie in the length and shape of the kinocilium.In bullfrog, Hillman found that, almost every receptor of the saccular macula has a kinocilium that is expanded at its distal end to form a large bulb (Fig. 1) which is connected to the tips of the several longest stereocilia and to the membrane supporting the otolith. Thus the entire kinocilium is no longer than the longest stereocilia.

The development of the posterior body in zebrafish

Development ◽  
1997 ◽  
Vol 124 (4) ◽  
pp. 881-893 ◽  
Author(s):  
J.P. Kanki ◽  
R.K. Ho
Keyword(s):  
Cell Proliferation ◽  
Expression Patterns ◽  
Time Lapse ◽  
Paraxial Mesoderm ◽  
Vertebrate Development ◽  
Fate Map ◽  
Cell Fates ◽  
Cell Movements ◽  
Body Development ◽  
Bilateral Distribution

In order to understand the developmental mechanisms of posterior body formation in the zebrafish, a fate map of the zebrafish tailbud was generated along with a detailed analysis of tailbud cell movements. The fate map of the zebrafish tailbud shows that it contains tissue-restricted domains and is not a homogeneous blastema. Furthermore, time-lapse analysis shows that some cell movements and behaviors in the tailbud are similar to those seen during gastrulation, while others are unique to the posterior body. The extension of axial mesoderm and the continuation of ingression throughout zebrafish tail development suggests the continuation of processes initiated during gastrulation. Unique properties of zebrafish posterior body development include the bilateral distribution of tailbud cell progeny and the exhibition of different forms of ingression within specific tailbud domains. The ingression of cells in the anterior tailbud only gives rise to paraxial mesoderm, at the exclusion of axial mesoderm. Cells of the posterior tailbud undergo subduction, a novel form of ingression resulting in the restriction of this tailbud domain to paraxial mesodermal fates. The intermixing of spinal cord and muscle precursor cells, as well as evidence for pluripotent cells within the tailbud, suggest that complex inductive mechanisms accompany these cell movements throughout tail elongation. Rates of cell proliferation in the tailbud were examined and found to be relatively low at the tip of the tail indicating that tail elongation is not due to growth at its posterior end. However, higher rates of cell proliferation in the dorsomedial region of the tail may contribute to the preferential posterior movement of cells in this tailbud region and to the general extension of the tail. Understanding the cellular movements, cell fates and gene expression patterns in the tailbud will help to determine the nature of this important aspect of vertebrate development.

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