Noradrenergic modulation of neuronal responses to glutamate in the vestibular complex
Neuroscience Letters. 2009-10-01; 464(3): 173-178
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1. Neurosci Lett. 2009 Oct 30;464(3):173-8. doi: 10.1016/j.neulet.2009.08.035. Epub
2009 Aug 20.
Noradrenergic modulation of neuronal responses to glutamate in the vestibular
Barresi M(1), Caldera M, Grasso C, Li Volsi G, Licata F, Santangelo F.
(1)Dipartimento di Scienze Fisiologiche (University of Catania), Catania, Italy.
Increases in firing rate induced in secondary vestibular neurons by
microiontophoretic application of glutamate were studied during long-lasting
applications of noradrenaline (NA) and/or its antagonists and agonists.
Sixty-nine percent of the tested neurons, scattered through all nuclei of the
vestibular complex, modified their responsiveness to glutamate in the presence of
NA. The effects were depressive in a majority (40%) and enhancing in a minority
(29%) of cases. NA application depressed responses to glutamate more often than
it increased them in lateral, medial and superior vestibular nuclei, while the
reverse was true for the spinal nucleus. The mean intensities of NA-evoked
effects were comparable in the various nuclei. The enhancing effects of NA were
antagonized by application of the alpha2 receptor antagonist yohimbine, and their
depressive effects were enhanced by the beta receptor antagonist timolol. It is
concluded that NA exerts a control on the processing of vestibular information
and that this modulation is exerted by at least two mechanisms involving alpha2
and beta noradrenergic receptors.
PMID: 19699262 [Indexed for MEDLINE]