Received February 21, 2007
Revised March 13, 2007
Accepted after revision April 10, 2007
Autonomic Neuroscience [200]
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The Dorsomedial Hypothalamus activates PVN neurones via a tachykinin pathway
Matthew D Womack 1
Richard Barrett-Jolley 2*
1 University of Liverpool
2 Liverpool University
* To whom correspondence should be addressed. E-mail: rbj{at}liv.ac.uk.
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Abstract |
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The dorsomedial hypothalamus (DMH) innervates the paraventricular nucleus (PVN) with substance P (SP) immunoreactive neurones. The PVN itself powerfully influences both the neuroendocrine & 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 synaptic block with a high Mg2+/low Ca2+ buffer solution. Crucially, the selective NK1 antagonist L-703606 also inhibited DMH to PVN neurotransmission. Thus, we show for the first time, an excitatory connection between the DMH and PVN utilising tachykinin NK1 receptors. This pathway may be important for the hypothalamic control of neuroendocrine and/or cardiovascular function.
Key Words:
Hypothalamus, Stress, Tachykinin
