ePrints

The effects of general anaesthetics on carbachol-evoked gamma oscillations in the rat hippocampus in vitro

Lookup NU author(s): Professor Miles Whittington

Downloads

Full text for this publication is not currently held within this repository. Alternative links are provided below where available.

Abstract

The effects of general anaesthetics and temperature on carbachol-evoked gamma oscillations in the rat hippocampal brain slice preparation were investigated. The frequency of the oscillations was found to be dependent on temperature in the range 32–25 °C, with a linear reduction in frequency from 40–17 Hz over this temperature range. The volatile anaesthetics isoflurane and halothane, and the intravenous anaesthetics thiopental, propofol and R(+)-etomidate caused a reduction in the frequency of the oscillations, in a concentration-dependent manner, over a range of clinically relevant concentrations. On the other hand, the intravenous agent ketamine and the “inactive” S(−)-isomer of etomidate had no significant effect on the oscillation frequency. The oscillations were markedly asymmetric over one cycle with a relatively rapid “rising” phase followed by a slower “decaying” phase. The decrease in oscillation frequency was due to an increase in the time-course of the “decaying phase” of the oscillation with little effect on the “rising” phase, consistent with the idea that carbachol-evoked gamma oscillations are trains of GABAergic inhibitory postsynaptic potentials and that the anaesthetics are acting postsynaptically at the GABAA receptor.

Publication metadata

Author(s): Whittington MA; Dickinson R; Awaiz S; Lieb WR; Franks NP

Publication type: Article

Publication status: Published

Journal: Neuropharmacology

Year: 2003

Volume: 44

Issue: 7

Pages: 864-872

ISSN (print): 0028-3908

ISSN (electronic): 1873-7064

Publisher: Pergamon

URL: http://dx.doi.org/10.1016/S0028-3908(03)00083-2

DOI: 10.1016/S0028-3908(03)00083-2

Altmetrics

Share