Orexin A affects GABAa receptor recirculation after stimulation with Propofol

Abstract

Propofol, the intravenous anaesthetic, involves the GABAA receptors in its signalling/ncascade, altering the vesicular transport and inducing neurite retraction. The neuropeptide Orexin A, produced by the lateral and posterior hypothalamus has an essential role regulating the arousal system. It is capable of reducing the anaesthetic effects of various anaesthetic drugs as well as enhancing wakefulness in rats. Recent data from our lab suggests that Orexin A can affect the recirculation of the GABAA receptors. In order to further understand the anaesthetic mechanism of Propofol and how Orexin A can revert its effect, we wanted to investigate the effect of Orexin A on GABAA receptors in Propofol-treated SHSY5Y cells. Samples were treated with medium (control), Propofol, Orexin A or Orexin A + Propofol and immunofluorescent labelling was performed against GABAA receptor β2 and α1 subunits. We could see the number of surface receptors was reduced in the double-treated cells compared to the others. However, the quantitation of signal intensities did not result in any significant differences between treatments.