Discontinuous volume transitions in ionic gels and their possible involvement in the nerve excitation process

Abstract

Discontinuous volume changes in polymer gels carrying negatively ionized groups were studied by varying the molarities of univalent and bivalent cations in the bathing solution. These studies offer a sound basis for elucidating the origin of rapid swelling and heat production in nerve fibers associated with the process of excitation.

Hydrogel Films on Optical Fiber Core: Properties, Challenges, and Prospects for Future Applications

“…Interestingly, at the same molar ratios of divalent to monovalent cations, ~ 1 mM to 30 mM, respectively, similar volume changes were observed in biological polyelectrolyte systems during physiological processes like nerve excitation, musle contraction, and cell locomotion [34][35][36][37][38][39][40].…”

“…Interestingly, at the same molar ratios of divalent to monovalent cations, ~ 1 mM to 30 mM, respectively, similar volume changes were observed in biological polyelectrolyte systems during physiological processes like nerve excitation, musle contraction, and cell locomotion [34][35][36][37][38][39][40].Surfactants. The extensive theoretical [41][42][43] and experimental [44][45][46][47][48] studies have shown that addition of anionic, cationic, and nonionic surfactants to the solution containing a gel can also influence the volume phase transition temperature and swelling degree of hydrogels depending on their hydrophobicity and charge of the polymer network.…”

Information, Noise and Communication: Thresholds as Controlling Elements in Development

“…At a critical concentration, a threshold is passed and the gel abruptly contracts. Data adapted from Tasaki and Byrne (1992) The second possibility is that described by Bray and Duke (2004) as Conformational Spread. They report the evidence that from a number of systems, for example, actin filaments and others, conformational changes can propagate through extended lattices of protein molecules.…”

Extracellular matrix and its role in conveying glial/neural interactions in health and disease

“…Again, the pioneer in exploring volume phase transitions of polyelectrolytes in the context of nerve excitation was Ichigi Tasaki (Tasaki and Byrne [67,68]; Tasaki [64,65]). He also measured the liberation of heat at wave onset both in action potentials and retinal spreading depressions (Tasaki and Iwasa [70]; Tasaki and Byrne [66]) phenomena that we now associate with relaxation of structured interfacial water involved in the polyelectrolyte response to changes induced by electrical and/or mechanical stimulation.…”