Korean J Anesthesiol Search

CLOSE


Korean J Anesthesiol > Volume 56(6); 2009 > Article
Korean Journal of Anesthesiology 2009;56(6):675-680.
DOI: https://doi.org/10.4097/kjae.2009.56.6.675   
Comparison of the GABAergic currents associated with midazolam and propofol in rat hippocampal neurons.
Sang Woo Chun, Yong Son
1Department of Oral Physiology, College of Dentistry, School of Medicine, Wonkwang University, Iksan, Korea.
2Department of Anesthesiology and Pain Medicine, School of Medicine, Wonkwang University, Iksan, Korea. yongson@wonkwang.ac.kr
Abstract
BACKGROUND
gamma-Aminobutyric acid (GABA), the principal inhibitory neurotransmitter, activates persistent low amplitude tonic currents in several brain regions, in addition to conventional synaptic currents. Tonic conductance is highly sensitive to low concentrations of volatile anesthetics and therefore might contribute to amnestic properties. We compared the properties of GABAergic tonic currents mediated by sedative-amnestic midazolam and anesthetic propofol in rat hippocampal neurons.
METHODS
Patch clamp techniques were used to characterize the GABAergic currents recorded in CA1 pyramidal neurons in rat hippocampal slices. The amplitude of the tonic currents and the decay of miniature inhibitory postsynaptic currents (mIPSCs) were measured after administration of midazolam or propofol.
RESULTS
Both midazolam and propofol caused concentration dependent increases in the tonic currents. The enhancement of the tonic currents by midazolam concentrations of greater than 0.5 microM caused no further increase in current amplitude. Propofol continued to increase with concentrations over the range tested (0.1-10 microM). Low concentrations of midazolam 0.01 microM and propofol 0.5 microM selectively enhanced the tonic currents but failed to alter mIPSCs.
CONCLUSIONS
Low concentrations of midazolam and propofol selectively enhanced the tonic currents but not synaptic currents of rat hippocampal pyramidal neurons. Unlike midazolam, the response to propofol did not become saturated and had a greater effect on the tonic currents.
Key Words: GABA; Hippocampus; Midazolam; Propofol; Tonic currents
TOOLS
Share :
Facebook Twitter Linked In Line it
METRICS Graph View
  • 0 Crossref
  •   Scopus
  • 1,108 View
  • 10 Download


ABOUT
ARTICLE CATEGORY

Browse all articles >

BROWSE ARTICLES
AUTHOR INFORMATION
Editorial Office
101-3503, Lotte Castle President, 109 Mapo-daero, Mapo-gu, Seoul 04146, Korea
Tel: +82-2-792-5128    Fax: +82-2-792-4089    E-mail: journal@anesthesia.or.kr                

Copyright © 2022 by Korean Society of Anesthesiologists.

Developed in M2PI

Close layer
prev next