Pressure Effects on Mammalian Central Nervous System

Pressure represents a fundamental thermodynamic state variable and, as such, changes induced by pressure reflect alterations in reaction rates or equilibria. High pressure is expected to universally affect molecules such as membrane phospholipids and proteins such as enzymes, transporters, ionic channels, cytoskeleton, etc. In order to measure the electrical properties of neurons such as membrane resting potential, membrane resistance that can be calculated from the experimentally measured input resistance, and action potential (AP), intracellular recordings must be made. Alteration of channel kinetics by pressure will produce changes in a single AP shape, amplitude, duration, and conduction velocity. For many years the information on neuronal activity of mammalian brain was obtained by extracellular field potentials recorded either in vivo from rodents’ brain or in vitro from isolated rat brain structures or slices. Several patterns of AP activity have been tested under pressure conditions: Branch point failure, spontaneous repetitive firing, and rhythmic activity.