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Int J Physiol Pathophysiol Pharmacol 2012;4(2):94-98.

Brief Communication
Intra-ventrolateral preoptic nucleus injection of γ-aminobutyric acid induces
sedation in rats

Ming Xiong*, Jing Li*, Da Wang, Ellise Delphin, Jiang Hong Ye

Department of Anesthesiology, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, NJ, USA.
*These authors contribute equally to this work.

Received May 4, 2012; accepted May 25, 2012; Epub June 20, 2012; Published June 30, 2012

Abstract: The ventrolateral preoptic nucleus (VLPO) plays a critical role in regulating and maintaining sleep-awake cycle. It receives
both excitatory and inhibitory inputs and regulates the activity of tuberomamillary nucleus and other monoaminergic nuclei, which in turn
determines the alternation between wakefulness and non-rapid eye movement sleep (NREM)/sedation. Although a previous study has
shown that systematic administration of GABAergic anesthetic agents activated VLPO neurons, which is believed to be responsible for
the sedative effects of these agents, it is unknown whether a direct administration of γ-Aminobutyric acid (GABA) into the VLPO can
induce sedation. Here we report that rats that received intra-VLPO infusion of GABA demonstrated sustained reduction in locomotion,
most significantly during the 10-40th min period after infusion. Conversely, rats that received intra-VLPO infusion of noradrenaline
demonstrated a sustained increase in locomotion from 20th min after infusion. By contrast, no appreciable change was observed in
rats that received intra-VLPO infusion of glycine. This result demonstrates that exogenous GABA may activate sleep-active neurons in
the VLPO and promote sedation. (IJPPP1205001)

Keywords: Ventrolateral preoptic nucleus, GABA, sedation

Address all correspondence to:
Dr. Jiang Hong Ye
Department of Anesthesiology
UMDNJ, New Jersey Medical School
185 South Orange Avenue, Newark, New Jersey 07103, USA.
Tel: + 1973-972-1866; Fax: +1973-972-4172
E-mail: ye@umdnj.edu