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Activation of paraventricular nucleus neurones by the dorsomedial hypothalamus via a tachykinin pathway in rats
Author(s) -
Womack Matthew D.,
BarrettJolley Richard
Publication year - 2007
Publication title -
experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0958-0670
DOI - 10.1113/expphysiol.2007.037457
Subject(s) - hypothalamus , medicine , endocrinology , excitatory postsynaptic potential , neurotransmission , glutamate receptor , antagonist , tachykinin receptor , kynurenic acid , chemistry , neuropeptide , substance p , receptor , nucleus , neuroscience , biology
The dorsomedial hypothalamus (DMH) innervates the paraventricular nucleus (PVN) with substance P (SP) immunoreactive neurones. The PVN itself powerfully influences both the neuroendocrine and the cardiovascular systems. In this in vitro study, we examine the DMH‐to‐PVN pathway electrophysiologically. Glutamate application to the DMH increased action current frequency in the PVN. This effect was prevented by the glutamate antagonist kynurenic acid or by synaptic block with a high‐Mg 2 + low‐Ca 2 + buffer solution. Crucially, the selective tachykinin NK1 receptor antagonist L‐703606 also inhibited DMH‐to‐PVN neurotransmission. Thus we show, for the first time, an excitatory connection between the DMH and PVN that uses tachykinin NK1 receptors. This pathway may be important for the hypothalamic control of neuroendocrine and/or cardiovascular function.