Model of the Nerve Impulse with Account of Mechanosensory Processes: Stationary Solutions.

Mechanotransduction refers to a physiological process by which mechanical forces, such as pressures exerted by ionized fluids on cell membranes and tissues, can trigger excitations of electrical natures that play important role in the control of various sensory (i.e. stimuli-responsive) organs and homeostasis of living organisms. In this work, the influence of mechanotransduction processes on the generic mechanism of the action potential is investigated analytically, by considering a mathematical model that consists of two coupled nonlinear partial differential equations. One of these two equations is the Korteweg-de Vries equation governing the spatio-temporal evolution of the density difference between intracellular and extracellular fluids across the nerve membrane, and the other is Hodgkin-Huxley cable equation for the transmembrane voltage with a self-regulatory (i.e. diode-type) membrane capacitance. The self-regulatory feature here refers to the assumption that membrane capacitance varies with the difference in density of ion-carrying intracellular and extracellular fluids, thus ensuring an electromechanical feedback mechanism and consequently an effective coupling of the two nonlinear equations. The exact one-soliton solution to the density-difference equation is obtained in terms of a pulse excitation. With the help of this exact pulse solution the Hodgkin-Huxley cable equation is shown to transform, in steady state, to a linear eigenvalue problem some bound states of which can be obtained exactly. Few of such bound-state solutions are found analytically.

Integrin-Mimetic Mechanosensory Elastomer with Fluorescence Probe for Monitoring Chain Deformation in Situ

Mechanosensory elastomers attract intense interests in the academic and industrial fields.However,molecular insight of macroscopic properties remains a significant challenge.Herein,we build up a correlation between the microscopic and macroscopic level by designing a mechanosensory elastomer with aggregation-induced emission luminogens(AIEgens)that monitors chain deformation in situ.The key constituents are the mechanosensory units,which are dynamic dimers bonded by ureidopyrimidinone(UPy)groups and tetraphenylethylene(TPE)for the fluorescence signal output.The photoluminescence(PL)technique successfully monitors elastomer chain deformation under external forces.The PL intensity increases linearly at low elongation,in excellent agreement with Hooke’s law for ideal chains.Strong deviation from linear PL intensity is measured at high elongation,which can be theoretically described by the Langevin function.A correlation between the microscopic and the macroscopic level is then built.

Synaptic connections between different sensory channels in CNS of the leech modulate the input of mechanosensory information

The mechanism for transmission of sensory information concerning a specific sensory modality or submodality can be called a sensory channel, including the receptors, sensory pathways and the parts of the central nervous system that further process the sensory information . A certain sensory channel can be activated by a suitable stimulus. Sensory information is transduced by sensory receptor and is further transferred into central nervous system. The characteristics of a modality or submodality are mainly determined by the properties of the corresponding sensory receptors. However, besides the receptor properties, are there any other factors which have influence on the properties of a sensory modality? Is there a kind of gating mechanism existing which could selectively control the inputs of sensory information based on different sensory channels? Here we are trying to answer the above questions by studying the functional relationships between different mechanosensory modalities of leech.

Demystifying Mechanosensitive Piezo Ion Channels

Mechanosensitive channels mediate touch,hearing,proprioception,and blood pressure regulation.Piezo proteins,including Piezo1 and Piezo2,represent a new class of mechanosensitive channels that have been reported to play key roles in most,if not all,of these modalities.The structural architecture and molecular mechanisms by which Piezos act as mechanosensitive channels,however,remain mysterious.Two new studies have now provided critical insights into the atomic structure and molecular basis of the ion permeation and mechano-gating properties of the Piezo1 channel.