Proceedings of The Physiological Society

University College London December 2005 (2006) Proc Physiol Soc 1, PC10

Poster Communications

Histamine H3receptor-mediated inhibition of GABA release in the vestibular nucleus in normal and labyrinthectomized rats

Bergquist, Filip; Ruthven, Alasdair; Ludwig, Mike; Dutia, Mayank B.;

1. Centre for Integrative Physiology, Biomedical Sciences, Edinburgh University, Edinburgh, Lothian, United Kingdom.

Histamine depolarises vestibular neurones via H1 and H2 receptors (Wang & Dutia, 1995), and infusion of H2-receptor antagonists or H3-receptor agonists into the medial vestibular nucleus (MVN) induces a behavioural syndrome similar to that seen after unilateral labyrinthectomy (UL; Yabe et al. 1993). Presynaptic H3-receptors can act both as inhibitory autoreceptors and as inhibitory heteroreceptors, but it is not known if the latter mechanism has a role in vestibular function. To clarify this we investigated the histaminergic regulation of endogenous GABA release in superfused MVN slices. Slices were prepared from normal male Lister hooded rats and from animals which underwent left labyrinthectomy under halothane anaesthesia either 25 h or 7 days earlier (Yamanaka et al. 2000). The animals were decapitated under halothane anaesthesia and horizontal 400-450

Where applicable, experiments conform with Society ethical requirements