Effects of High Helium Pressure on Intracellular and Field Potential Responses in the CA1 Region of the In Vitro Rat Hippocampus
- 1 December 1996
- journal article
- Published by Wiley in European Journal of Neuroscience
- Vol. 8 (12), 2571-2581
- https://doi.org/10.1111/j.1460-9568.1996.tb01551.x
Abstract
We have investigated the effects of high helium pressure (up to 13.3 MPa) on the electrophysiological responses of CA1 neurons in rat hippocampal slices using a purpose built pressure chamber, designed to facilitate field potential and intracellular recording. In field potential experiments, near threshold orthodromic responses were depressed by modest pressure (0.4 MPa). At higher stimulus intensities, orthodromic and antidromic population spike amplitudes were not increased at 5 MPa but were significantly enhanced at 10 MPa, and multiple population spikes were observed in some experiments. Orthodromic paired pulse potentiation was not affected by pressure up to 10 MPa. In intracellular experiments there were no significant differences between mean values obtained for resting membrane potential and input resistance at atmospheric pressure and pressures of up to 10 MPa. However, spontaneous depolarizing membrane potential excursions, decreased slow after-hyperpolarization responses and reduced accommodation properties were observed at pressure (5-10 MPa). One possibility is that the SK and M potassium channel systems may be more sensitive to high pressure than other membrane ion channels. These effects may contribute towards the high pressure neurological syndrome observed in vivo.Keywords
This publication has 31 references indexed in Scilit:
- Pka mediates the effects of monoamine transmitters on the K+ current underlying the slow spike frequency adaptation in hippocampal neuronsNeuron, 1993
- The influence of helium pressure on the reduction induced in field potentials by various amino acids and on the gaba-mediated inhibition in the ca1 region of hippocampal slices in the ratNeuropharmacology, 1988
- Effects of hydrostatic pressure on membrane processes. Sodium channels, calcium channels, and exocytosis.The Journal of general physiology, 1987
- Effect of Pressure on the Release of Radioactive Glycine and ?-Aminobutyric Acid from Spinal Cord SynaptosomesJournal of Neurochemistry, 1987
- Hydrostatic pressure effects on the central nervous system: perspectives and outlookPhilosophical Transactions of the Royal Society of London. B, Biological Sciences, 1984
- Noradrenaline blocks accommodation of pyramidal cell discharge in the hippocampusNature, 1982
- Pressure dependence of the potassium currents of squid giant axonThe Journal of Membrane Biology, 1982
- Pressure dependence of the sodium currents of squid giant axonThe Journal of Membrane Biology, 1982
- Hydrostatic Pressure Does Not Antagonize Halothane Effects on Single Neurons of Aplysia californicaAnesthesiology, 1980
- Slowing of ionic currents in the voltage-clamped squid axon by helium pressureNature, 1975