This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Georgiev, S. K. Articles by Baba, H. Search for Related Content PubMed PubMed Citation Articles by Georgiev, S. K. Articles by Baba, H.

---

ANESTHETIC PHARMACOLOGY

Actions of Norepinephrine and Isoflurane on Inhibitory Synaptic Transmission in Adult Rat Spinal Cord Substantia Gelatinosa Neurons

Division of Anesthesiology, Niigata University Graduate School of Medical and Dental Sciences

Address correspondence and reprint requests to Hiroshi Baba, MD, PhD, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachidori, 951-8510 Niigata, Japan. Address e-mail baba{at}med.niigata-u.ac.jp.

Volatile inhaled anesthetics and nitrous oxide (N₂O) are often used together in clinical practice to produce analgesia. Because the analgesic effect of N₂O is, at least in part, mediated by norepinephrine (NE) release in the spinal cord, we examined the interaction between isoflurane (ISO) and NE in the adult rat spinal cord with respect to central nociceptive information processing. The effects of clinically relevant concentrations of ISO (1 MAC) and NE (20 µM) on spontaneous inhibitory transmission in substantia gelatinosa (SG) neurons were examined using the blind whole-cell patch-clamp method. ISO prolonged the decay time and increased the total charge transfer of spontaneous inhibitory postsynaptic currents. NE increased the frequency and mean amplitude of inhibitory postsynaptic currents and the charge transfer as well. Coapplication of both drugs led to an additive increase of the charge transfer and frequent temporal summation of inhibitory postsynaptic currents. We conclude that both ISO and NE enhance the inhibitory synaptic transmission in the rat SG neurons and their interaction is additive, suggesting that ISO may add to the analgesic action of N₂O at the spinal cord dorsal horn level.

This article has been cited by other articles:

				J. Kim, A. Yao, R. Atherley, E. Carstens, S. L. Jinks, and J. F. Antognini Neurons in the Ventral Spinal Cord Are More Depressed by Isoflurane, Halothane, and Propofol Than Are Neurons in the Dorsal Spinal Cord Anesth. Analg., October 1, 2007; 105(4): 1020 - 1026. [Abstract] [Full Text] [PDF]