HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 91/2/403    most recent expphysiol.2005.032409v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Cham, J. L. Articles by Badoer, E. Search for Related Content PubMed PubMed Citation Articles by Cham, J. L. Articles by Badoer, E.

¹ School of Medical Sciences, Division of Biosciences, RMIT University, PO Box 71, Bundoora 3083, Melbourne, Victoria, Australia² Institute of Biomedical Research, University of Sydney, Sydney, NSW 2006, Australia³ Howard Florey Institute, University of Melbourne, Melbourne, Victoria, VIC 3010, Australia

The rostral ventrolateral medulla (RVLM) is essential for the generation of sympathetic nerve activity. The RVLM receives a substantial innervation from the hypothalamic paraventricular nucleus (PVN). Activation of P2X purinoceptors via ATP has been shown to mediate fast excitatory synaptic neurotransmission. There is mounting evidence to suggest the presence of P2X purinoceptors in hypothalamic nuclei, including the PVN. In this study, we determined whether P2X₁–P2X₆ purinoceptor subtypes were present on PVN neurones that projected to the RVLM. Injection of the retrogradely transported tracer, rhodamine-tagged microspheres, into the pressor region of the RVLM was used to identify the neurones in the PVN that innervated the RVLM. P2X₁–P2X₆ purinoceptors were detected by immunohistochemistry. Double-labelled neurones were quantified and expressed as a proportion of the retrogradely labelled neurones. The proportions of double-labelled neurones for each of the P2X purinoceptor subtypes varied, on average, from 14 to 29%. The P2X₃ purinoceptor subtype was found to be the dominant purinoceptor subtype present on PVN neurones projecting to the RVLM. Additionally it was apparent that more than one P2X purinoceptor subtype was present on the PVN neurones projecting to the RVLM, since the sum of the average percentages of double-labelled neurones for each P2X purinoceptor subtype exceeded 100%. These findings highlight the presence of the P2X₁–P2X₆ purinoceptors on PVN neurones projecting to the RVLM. The results suggest a potential role for ATP in the PVN in the regulation of sympathetic nerve activity.

(Received 29 September 2005; accepted after revision 18 November 2005; first published online 18 November 2005)
Corresponding author E. Badoer: School of Medical Sciences, Division of Biosciences, RMIT University, PO Box 71, Bundoora 3083, Melbourne, Victoria, Australia. Email: emilio.badoer{at}rmit.edu.au

This article has been cited by other articles:

				P. M. Sonner and J. E. Stern Functional role of A-type potassium currents in rat presympathetic PVN neurones J. Physiol., August 1, 2007; 582(3): 1219 - 1238. [Abstract] [Full Text] [PDF]

				G. Burnstock Physiology and Pathophysiology of Purinergic Neurotransmission Physiol Rev, April 1, 2007; 87(2): 659 - 797. [Abstract] [Full Text] [PDF]