Interfacial dehydration by anesthetics: an electrocapillary study of surface charge density of adsorbed monolayer

Low susceptibility to inert gases and pressure symptoms in TREK-1-deficient mice

Nervous disorders may occur after an organism is saturated with inert gases, which may alter the lipid bilayer structure, according to their liposolubility coefficient. Increase in the nitrogen partial pressure induces a neurological syndrome called 'nitrogen narcosis'. By contrast, high pressures of helium induce epilepsy, an high-pressure nervous syndrome symptom. On the basis of an analogy with anaesthetic mechanisms, we used TREK-1 knockout mice, earlier described to volatile the anaesthetics resistance. These mice had a higher threshold of resistance to the narcotic effects of nitrogen and to the death after recurrent epileptic seizure induced by high pressure. TREK-1 channels seem to play a key role in modulating the anaesthetic potential of inert gases and in neuroprotection.

Effects of high hydrostatic pressures on living cells: a consequence of the properties of macromolecules and macromolecule-associated water

Sixty percent of the Earth's biomass is found in the sea, at depths greater than 1000 m, i.e., at hydrostatic pressures higher than 100 atm. Still more surprising is the fact that living cells can reversibly withstand pressure shifts of 1000 atm. One explanation lies in the properties of cellular water. Water forms a very thin film around macromolecules, with a heterogeneous structure that is an image of the heterogeneity of the macromolecular surface. The density of water in contact with macromolecules reflects the physical properties of their different domains. Therefore, any macromolecular shape variations involving the reorganization of water and concomitant density changes are sensitive to pressure (Le Chatelier's principle). Most of the pressure-induced changes to macromolecules are reversible up to 2000 atm. Both the effects of pressure shifts on living cells and the characteristics of pressure-adapted species are opening new perspectives on fundamental problems such as regulation and adaptation.