Evidence for a histaminergic input from the ventral tuberomammillary nucleus to
the solitary tract nucleus involved in arterial pressure regulation
#MMPMID28292881
Yamanaka K
; Gouraud SS
; Takagishi M
; Kohsaka A
; Maeda M
; Waki H
Physiol Rep
2017[Mar]; 5
(5
): ? PMID28292881
show ga
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.
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