Comparative Aspects of Mechanoreceptor Systems by B. Martinac, A. H. Delcour, M. Buechner, J. Adler, C. Kung

By B. Martinac, A. H. Delcour, M. Buechner, J. Adler, C. Kung (auth.), Professor Fumio Ito (eds.)

In the prior five years there was an incredible raise of proof that the ion channels activated by way of mechanical strength are universal to a large choice of phone varieties. Mechanosensitive (MS) ion channels shape a small percentage of the full channel inhabitants. they're now present in greater than 30 mobilephone kinds from E. coli, yeast, to plant, invertebrate, and vertebrate cells, the place they happen in nearly every kind of cells from bone to delicate muscle, in addition to neurons. the vast majority of MS channels are permeable to monovalent cations and are a bit of selective for okay+ over Na +. How­ 2 ever, there are numerous experiences of anion-selective MS channels, MS Ca + channels, and MS channels with huge conductances that don't dis­ criminate markedly among cations and anions. lately B. Hille has postulated attainable evolutionary relationships among different types of ion channels, with mechanosensitive channels predating even the eukaryotes. voltage-gated channel varieties originate with the stem eukaryotes, as deduced from the presence of voltage-gated okay+ 2 and Ca + channels in protozoa, algae, or greater vegetation. Agonist-gated chan­ nels in addition to voltage-gated Na + channels seem with the earliest metazoan animals, as deduced from the presence of Na + spikes and quickly chemical synapses in cnidaria (coelenterates), ctenophores, and all larger animals.

Show description

Read Online or Download Comparative Aspects of Mechanoreceptor Systems PDF

Best comparative books

Global Corruption Report 2007: Corruption in Judicial Systems

An exam of ways, why and the place corruption mars judicial techniques.

The Unauthorised Agent: Perspectives from European and Comparative Law

The point of interest of this e-book, the criminal state of affairs created whilst an agent acts with no authority, is without doubt one of the most vital concerns in organization legislation. The research is split into 3 sections: obvious authority, ratification and the legal responsibility of the falsus procurator. Adopting a special comparative viewpoint, the contributions are drawn from many alternative felony structures, supplying the chance for research of the ecu universal law/civil legislation divide.

Extra info for Comparative Aspects of Mechanoreceptor Systems

Example text

Gustin MS channel inhibitor such as Gd 3+ could be used to isolate mutants defective in MS channel function (see limitations of Gd3+ above). If MS channel function is required for graviception, then such mutants ought to be defective in graviception. In order to forge a genetic link between MS channels and mechanosensation in plants or fungi, the choice of experimental system is important. Three requirements of such a system are: 1. Methods for the isolation and analysis of mutants using genetic screens or selections based on a well-described physiological response to a mechanical stimulus; 2.

6 Concluding Remarks . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . 39 40 42 42 43 43 46 46 49 52 52 1 Mechanoreception and Cellular Behaviour Most living cells are mechanosensitive in that mechanical strain exerted on their plasma membrane results in a transient change in electrical conductance of the membrane. In cells unspecialized for mechanoreception, a mechanically induced "injury" would result in a membrane potential change due to traumatic leak currents.

Model #1, first proposed by Sachs (Guharay and Sachs 1984), predicts a Boltzmann function for MS channel gating, wherein the ratio of Popen and Pclosed is an exponential function of the square of the membrane tension. This prediction is a consequence of the following reasoning: "membrane tension does work on a Hooke's law elastic element, and this free energy, ~G, is used to open the channel" (Sachs 1989). The following three equations of model 1 yield, respectively: 1. The tension, T m, from stretching the elastic element, M T m =KA-' A (2) where KA =area elastic constant of the channel, M =change in area of the channel in the plane of the membrane for a given T m, A = area of the channel in the plane of the membrane.

Download PDF sample

Rated 4.50 of 5 – based on 7 votes