Sensory Receptors

The Neuron ◽  
2015 ◽  
pp. 295-326
Author(s):  
Irwin B. Levitan ◽  
Leonard K. Kaczmarek
Keyword(s):  
Plasma Membrane ◽  
Ion Channels ◽  
Hair Cells ◽  
Cyclic Nucleotides ◽  
Second Messengers ◽  
External Stimulus ◽  
Sensory Cells ◽  
Taste Receptors ◽  
Sensory Receptors ◽  
External Stimuli

Sensory cells have evolved pathways that allow ion channels to be regulated by external stimuli such as movement, light, or chemicals. In some cases, such as in photoreceptors and olfactory and taste receptors, the means by which the external stimulus is transduced is reasonably well understood. Such cells appear to handle information in ways similar to those used by neurons that deal with information coming from a presynaptic pathway, by altering the levels of second messengers such as cyclic nucleotides, which then open or close ion channels in the plasma membrane. In contrast, in mechanoreceptors, which include touch receptors and hair cells of the cochlea that are required for hearing, movement is directly linked to the gating of ion channels.

Cytoskeletal functions in sensory receptors

1989 ◽  
Vol 47 ◽  
pp. 796-797
Author(s):  
Beth Burnside
Keyword(s):  
Hair Cells ◽  
Outer Segment ◽  
Olfactory Receptors ◽  
Sensory Cells ◽  
Basal Bodies ◽  
Sensory Receptors ◽  
Structural Requirements ◽  
Auditory Hair Cells ◽  
Receptor Proteins ◽  
Taste Cells

Since the shapes of sensory receptors are so exquisitely specialized for mediating their unique functions, the cytoskeletons of sensory cells are deployed for morphogenetic and motile objectives in particularly interesting ways. Receptors erect cytoskeletal scaffolding to support two basic sorts of surface elaborations: 1) those designed to achieve the most effective presentation of specialized membrane laden with receptor proteins (photoreceptors, olfactory receptors, taste cells, and chemoreceptors), and 2) those designed to respond directly to mechanical perturbations in the cell's environment (auditory hair cells, mechanoreceptors). Each of these receptor types has specific structural requirements.Sensory receptors have built their surface elaborations upon either microtubule- or actin-based scaffoldings. Microtubule-based scaffoldings have evolved from motile cilia, and the axoneme has been modified to various ends. All ciliary-derived receptors so far described, except (curiously) those from the worm Caenorhabdites elegans, are associated with basal bodies which nucleate the assembly of surface specializations. The mechanisms for elaborating the myriad membrane specializations associated with ciliary receptors are not yet understood. Recently it has been shown that in vertebrate photoreceptors, actin is not required for the addition of membrane to the outer segment, but it is required for the proper assembly of new disks .

Drosophila Hören: Mechanismen und Gene

e-Neuroforum ◽  
2014 ◽  
Vol 20 (3) ◽  
Author(s):  
Maike Kittelmann ◽  
Martin Göpfert
Keyword(s):  
Drosophila Melanogaster ◽  
Transcription Factors ◽  
Ion Channels ◽  
Hair Cells ◽  
Motor Proteins ◽  
Fruit Fly ◽  
Sensory Organ ◽  
Sensory Cells ◽  
Mechanical Vibrations ◽  
Signalling Cascades

AbstractDrosophila hearing: mechanisms and genes.The fruit fly Drosophila melanogaster communicates acoustically and hears with its antennae. Fundamental aspects of hearing can be studied in these antennal ears. Their auditory sensory cells are evolutionarily related with vertebrate hair cells and are developmentally specified by homologous transcription factors. Like vertebrate hair cells, Drosophila auditory sensory cells are also motile and actively amplify the mechanical vibrations that they transduce. This transduction and amplification rely on the interplay between mechanically activated ion channels and motor proteins, whose movement impacts on the macroscopic performance of the ear. First molecular trans­ducer components have been identified and various auditory relevant proteins have been described. Several of these proteins are conserved components of cilia, putting forward the fly’s ear as a model for human ciliopathies. Also the evolution of sensory signalling cascades can be studied using the fly’s ear as the fly employs key Chemo-and Photoreceptor proteins to hear. Evidence is also accumulating that the fly’s ear is a multifunctional sensory organ that, in addition to mediating hearing, serves the detection of wind and gravity and, presumably, temperature.

scholarly journals Regulation of ion channels by inositol trisphosphate and diacylglycerol

1986 ◽  
Vol 124 (1) ◽  
pp. 323-335 ◽  
Author(s):  
M. J. Berridge
Keyword(s):  
Skeletal Muscle ◽  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Ion Channels ◽  
Second Messengers ◽  
Inositol Trisphosphate ◽  
Ionic Channels ◽  
Calcium Dependent ◽  
Intracellular Organelles ◽  
Active Calcium

Calcium-mobilizing receptors function to regulate ion channels located not only in the plasma membrane but also across the membranes of intracellular organelles, particularly the endoplasmic reticulum. A characteristic feature of such receptors is that they stimulate the hydrolysis of an inositol lipid to generate a pair of second messengers. Diacylglycerol remains within the plasma membrane where it activates protein kinase C leading to the phosphorylation of proteins some of which may regulate specific ionic channels, such as the calcium-dependent potassium channel or the Na+/H+ exchanger which regulates intracellular pH. The inositol trisphosphate (Ins 1,4,5P3) released to the cytosol functions as a second messenger to release calcium from the endoplasmic reticulum. The Ins 1,4,5P3 acts on a specific receptor to enhance the passive efflux of calcium while having no effect on the active calcium pump. There are indications that this Ins 1,4,5P3-induced release of calcium from an internal membrane store might provide an explanation of excitation-contraction coupling in skeletal muscle. Skinned skeletal muscle cells can be induced to contract by adding Ins 1,4,5P3. Mobilization of calcium from intracellular reservoirs by Ins 1,4,5P3 may thus prove to be a ubiquitous and fundamental mechanism for regulating cellular activity.

Mechanisms and genes in Drosophila hearing

e-Neuroforum ◽  
2014 ◽  
Vol 20 (3) ◽  
Author(s):  
M. Kittelmann ◽  
M.C. Göpfert
Keyword(s):  
Drosophila Melanogaster ◽  
Ion Channels ◽  
Auditory System ◽  
Hair Cells ◽  
Motor Proteins ◽  
Fruit Fly ◽  
Signaling Cascades ◽  
Sensory Organ ◽  
Sensory Cells ◽  
Sensory Signaling

AbstractThe fruit fly Drosophila melanogaster com­municates acoustically and hears with its an­tennae. Fundamental aspects of hearing can be studied in these antennal ears, the audi­tory sensory cells of which are evolutionarily related to vertebrate hair cells and are spec­ified developmentally by homologous tran­scription factors. Like vertebrate hair cells, Drosophila auditory sensory cells are also mo­tile and actively amplify the mechanical vi­brations they transduce. The transduction and amplification mechanisms rely on the in­terplay between mechanically activated ion channels and motor proteins, whose move­ment impacts upon the macroscopic perfor­mance of the ear. The first molecular trans­ducer components have been identified and various auditory system-relevant proteins have been described. Several of these pro­teins are conserved components of cilia, sug­gesting the fly’s ear as a model for human cil­iopathies. The evolution of sensory signaling cascades can also be studied using the fly’s ear, as the fly employs key chemo- and pho­toreceptor proteins to hear. Evidence is al­so accumulating that the fly’s ear is a multi­functional sensory organ, which, in addition to mediating hearing, serves to detect wind, gravity and presumably temperature.

Fluorocitrate Neural Dystrophy of the Guinea Pig Cochlea

1975 ◽  
Vol 33 ◽  
pp. 368-369
Author(s):  
G.J. Spector ◽  
C.D. Carr ◽  
I. Kaufman Arenberg ◽  
R.H. Maisel
Keyword(s):  
Hearing Loss ◽  
Hair Cells ◽  
Sodium Phosphate ◽  
Sensory Cells ◽  
Barium Salt ◽  
Perfusion Medium ◽  
Cochlear Hair Cells ◽  
Neural Degeneration ◽  
Sodium Phosphate Buffer ◽  
Cochlear Neurons

All studies on primary neural degeneration in the cochlea have evaluated the end stages of degeneration or the indiscriminate destruction of both sensory cells and cochlear neurons. We have developed a model which selectively simulates the dystrophic changes denoting cochlear neural degeneration while sparing the cochlear hair cells. Such a model can be used to define more precisely the mechanism of presbycusis or the hearing loss in aging man.Twenty-two pigmented guinea pigs (200-250 gm) were perfused by the perilymphatic route as live preparations using fluorocitrate in various concentrations (15-250 ug/cc) and at different incubation times (5-150 minutes). The barium salt of DL fluorocitrate, (C6H4O7F)2Ba3, was reacted with 1.0N sulfuric acid to precipitate the barium as a sulfate. The perfusion medium was prepared, just prior to use, as follows: sodium phosphate buffer 0.2M, pH 7.4 = 9cc; fluorocitrate = 15-200 mg/cc; and sucrose = 0.2M.

Intracellular trafficking and cytoplasmic streaming under abiotic stress conditions

2019 ◽  
Vol 6 (04) ◽  
Author(s):  
JESHIMA KHAN YASIN ◽  
ANIL KUMAR SINGH
Keyword(s):  
Plasma Membrane ◽  
Abiotic Stress ◽  
Confocal Microscopy ◽  
Fusion Protein ◽  
Intracellular Trafficking ◽  
Cytoplasmic Streaming ◽  
Living Cells ◽  
Stress Conditions ◽  
Vesicle Formation ◽  
External Stimuli

Cytoplasmic streaming is one among the vital activities of the living cells. In plants cytolplasmic streaming could clearly be seen in hypocotyls of growing seedlings. To observe cytoplsmic streaming and its correlated intracellular trafficking an investigation was conducted in legumes in comparison with GFP-AtRab75 and 35S::GFP:δTIP tonoplast fusion protein expressing arabidopsis lines. These seedlings were observed under confocal microscopy with different buffer incubation treatments and under different stress conditions. GFP expressing 35S::GFP:δTIP tonoplast lines were looking similar to the control lines and differ under stress conditions. Movement of cytoplasmic invaginations within the tonoplast and cytoplasmic sub vesicle or bulb budding during cytoplasmic streaming was observed in hypocotyls of At-GFP tonoplast plants. We found the cytoplasmic bulbs/ vesicles or sub vesicle formation from the plasma membrane. The streaming speed also depends on the incubation medium in which the specimen was incubated, indicating that the external stimuli as well as internal stimuli can alter the speed of streaming

Sensory Transduction

2019 ◽  
Author(s):  
Gordon L. Fain
Keyword(s):  
Ion Channels ◽  
Receptor Cell ◽  
Electrical Response ◽  
Second Messengers ◽  
Sensory Transduction ◽  
Sensory Receptor ◽  
Signal Pathways ◽  
Sense Organs ◽  
Sensory Physiology ◽  
Effector Molecules

Sensory Transduction provides a thorough and easily accessible introduction to the mechanisms that each of the different kinds of sensory receptor cell uses to convert a sensory stimulus into an electrical response. Beginning with an introduction to methods of experimentation, sensory specializations, ion channels, and G-protein cascades, it provides up-to-date reviews of all of the major senses, including touch, hearing, olfaction, taste, photoreception, and the “extra” senses of thermoreception, electroreception, and magnetoreception. By bringing mechanisms of all of the senses together into a coherent treatment, it facilitates comparison of ion channels, metabotropic effector molecules, second messengers, and other components of signal pathways that are common themes in the physiology of the different sense organs. With its many clear illustrations and easily assimilated exposition, it provides an ideal introduction to current research for the professional in neuroscience, as well as a text for an advanced undergraduate or graduate-level course on sensory physiology.

Inhibition of Na transport by 2-chloroadenosine: dissociation from production of cyclic nucleotides

1990 ◽  
Vol 68 (10) ◽  
pp. 1357-1362
Author(s):  
Russell F. Husted ◽  
Gerard P. Clancy ◽  
Abigail Adams-Brotherton ◽  
John B. Stokes
Keyword(s):  
Adenosine Receptors ◽  
Cyclic Nucleotides ◽  
Cell Function ◽  
Apical Membrane ◽  
Second Messengers ◽  
Basolateral Membrane ◽  
Primary Cultures ◽  
Good Evidence ◽  
Camp Content ◽  
Adenosine Transport

The adenosine analogue 2-chloroadenosine (2-CA) is often used to determine the biologic effects of adenosine because 2-CA is less susceptible to degradation than adenosine. We studied the effects of 2-CA on primary cultures of rat inner medullary collecting ducts because there is good evidence that adenosine can influence cell function through its effects on second messengers. 2-CA inhibited Na+ transport across the apical membrane and increased cAMP content of the cells. The major adenosine receptors in these cells appear to be the stimulatory (A2) type. Stimulation of cAMP by 2-CA was more potent when applied to the apical membrane than to the basolateral membrane, an effect opposite to that of vasopressin. These results imply that adenosine receptors are more numerous or more effective on the apical membrane than on the basolateral membrane. Inhibition of Na+ transport was probably not mediated by an adenosine receptor as evidenced by (i) a lack of effect of adenosine and other adenosine analogues on Na+ transport; (ii) a lack of effect of nonmetabolizable cyclic nucleotides on Na+ transport; and (iii) a clear discrepancy in the temporal course of 2-CA effects on a second messenger system (cAMP) and 2-CA inhibition of Na+ transport. Dipyridimole, an inhibitor of adenosine transport, also reduced Na+ transport. Taken together, the data suggest that 2-CA inhibits Na+ transport by interfering with adenosine transport or metabolism.Key words: cAMP, cGMP, 2-chloroadenosine, vasopressin, Na+ transport, dipyridimole, adenosine metabolism.

Hydrostatic pressure effects on vestibular hair cell afferents in fish and crustacea

2003 ◽  
Vol 13 (4-6) ◽  
pp. 235-242
Author(s):  
Peter J. Fraser ◽  
Stuart F. Cruickshank ◽  
Richard L. Shelmerdine
Keyword(s):  
Hydrostatic Pressure ◽  
Hair Cells ◽  
Signal To Noise Ratio ◽  
Angular Acceleration ◽  
Pressure Effects ◽  
Sensory Cells ◽  
Associated Gas ◽  
Piston Mechanism ◽  
New Finding ◽  
Resting Activity

Following the discovery of a hydrostatic pressure sensor with no associated gas phase in the crab, and the knowledge that several systems of cells in culture show long term alterations to small changes in hydrostatic pressure, we show here that vestibular type II hair cells in a well known model system (the isolated elasmobranch labyrinth), are sensitive to hydrostatic pressure. This new finding for the vertebrate vestibular system may provide an explanation for low levels of resting activity in vertebrate hair cells and explain how fish without swim bladders sense hydrostatic cues. It could have implications for humans using their balancing systems in hypobaric or hyperbaric environments such as in aircraft or during space exploration. Although lacking the piston mechanism thought to operate in crab thread hairs which sense angular acceleration and hydrostatic pressure, the vertebrate system may use larger numbers of sensory cells with resultant improvement in signal to noise ratio. The main properties of the crab hydrostatic pressure sensing system are briefly reviewed and new experimental work on the isolated elasmobranch labyrinth is presented.

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