Open AccessEvidence for a histaminergic input from the ventral tuberomammillary nucleus to the solitary tract nucleus involved in arterial pressure regulation
Author(s) -
Yamanaka Ko,
Gouraud Sabine S.,
Takagishi Miwa,
Kohsaka Akira,
Maeda Masanobu,
Waki Hidefumi
Publication year - 2017
Publication title -
physiological reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 39
ISSN - 2051-817X
DOI - 10.14814/phy2.13095
Subject(s) - histaminergic , microinjection , bicuculline , solitary nucleus , nucleus , medicine , endocrinology , area postrema , stimulation , receptor , neuroscience , antagonist , biology
The tuberomammillary nucleus ( TMN ) of the posterior hypothalamus has a high density of histaminergic neurons, the projection fibers of which are present in many areas of the brain, including the nucleus tractus solitarius ( NTS ), which controls arterial pressure ( AP ). In this study, we investigated whether the TMN – NTS pathway is involved in central cardiovascular regulation. Bicuculline, a gamma‐aminobutyric acid type A ( GABA A ) receptor antagonist, was microinjected into the ventral TMN of anesthetized rats and its effects on AP and heart rate ( HR ) were observed. We also evaluated the effect of cetirizine, an H 1 receptor antagonist, microinjected into the NTS on cardiovascular responses induced by electrical stimulation of the TMN . Both AP and HR increased following bicuculline microinjection into the ventral TMN . Similar pressor and tachycardic responses were observed after electrical stimulation of the ventral TMN . Microinjection of cetirizine into the NTS partially inhibited the pressor response but had no effect on HR . Finally, the treadmill test was associated with a high level of c‐Fos expression in both ventral TMN and NTS neurons. These results suggest that the TMN – NTS pathway is involved in regulation of AP , presumably under a high‐arousal phase, such as that during exercise.