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

This Article Full Text (PDF) 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 Paton, J F Articles by Spyer, K M Search for Related Content PubMed PubMed Citation Articles by Paton, J F Articles by Spyer, K M

Department of Physiology, Royal Free Hospital School of Medicine, London.

1. In this study we have examined the roles of the lateral parabrachial nucleus (lateral PBN) and nucleus tractus solitarius (NTS) as sites mediating the circulatory responses evoked from lobule IX b of the posterior cerebellar vermis in the decerebrate and anaesthetized decerebrate rabbit. Microinjection of either kainic acid or bicuculline into the lateral PBN and NTS was undertaken to assess the importance of neurones and GABAergic mechanisms, respectively, in expressing the cardiovascular responses evoked from lobule IX b. 2. In both the decerebrate and anaesthetized decerebrate rabbit activation of neurones within the lateral PBN with a microinjection of glutamate elicited tachycardia and a pressor response together with an increase in renal sympathetic nerve discharge and vasoconstriction in the hindlimb. A microinjection of GABA into the lateral PBN evoked an opposite pattern of response. Chemical lesioning of neurones within the rostral region of the lateral PBN or pharmacological blockade of GABAA receptor, abolished or significantly attenuated the cardiovascular response (bradycardia/depressor effect) evoked from lobule IX b in the anaesthetized decerebrate rabbit. 3. In the decerebrate animal the tachycardia/pressor response elicited from lobule IX b was suppressed when either kainic acid or bicuculline was microinjected into the caudal division of the lateral PBN. 4. A bradycardia, depressor response, an abolition of on-going renal nerve activity and vasodilatation in the femoral bed were evoked by activating neurones within a restricted region of the NTS with glutamate in the decerebrate and anaesthetized decerebrate rabbit. A microinjection of GABA into the NTS produced a qualitatively opposite pattern of response. The bradycardia/depressor response evoked from lobule IX b in the anaesthetized decerebrate rabbit was not altered significantly following a microinjection of either kainic acid or bicuculline into the ipsilateral NTS. However, in the decerebrate preparation following a microinjection of bicuculline into the ipsilateral NTS the tachycardia/pressor response evoked from IX b was either abolished or in many cases reversed to the pattern of response seen in the anaesthetized decerebrate rabbit. 5. The present experiments provide evidence for two functionally distinct pathways from the cardiovascular region of lobule IX b to the lateral PBN.(ABSTRACT TRUNCATED AT 400 WORDS)

This article has been cited by other articles:

				W. Sun and W. M. Panneton The caudal pressor area of the rat: its precise location and projections to the ventrolateral medulla Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2002; 283(3): R768 - R778. [Abstract] [Full Text] [PDF]

				S. M. Barman, H. L. Kitchens, A. B. Leckow, and G. L. Gebber Pontine neurons are elements of the network responsible for the 10-Hz rhythm in sympathetic nerve discharge Am J Physiol Heart Circ Physiol, October 1, 1997; 273(4): H1909 - H1919. [Abstract] [Full Text] [PDF]

				E. Mezey, Z. E. Toth, D. N. Cortright, M. K. Arzubi, J. E. Krause, R. Elde, A. Guo, P. M. Blumberg, and A. Szallasi Distribution of mRNA for vanilloid receptor subtype 1 (VR1), and VR1-like immunoreactivity, in the central nervous system of the rat and human PNAS, March 28, 2000; 97(7): 3655 - 3660. [Abstract] [Full Text] [PDF]