Ga. Lambert et al., RESPONSES OF THE DURAL CIRCULATION TO ELECTRICAL-STIMULATION OF TEE TRIGEMINAL GANGLION IN THE CAT, Clinical and experimental pharmacology and physiology, 24(6), 1997, pp. 377-390
1. In cats anaesthetized with alpha-chloralose, electrical stimulation
(ES) of the trigeminal ganglion produced a fall in blood pressure, a
predominantly ipsilateral dilatation in the common carotid vascular be
d and bilateral dilatation of the middle meningeal vascular bed, Secti
on of the trigeminal root abolished these responses, 2, Dilatation in
the middle meningeal artery was not affected by section of the cervica
l sympathetic trunk nor by the section of the seventh cranial nerve tr
unk, The dilator response was abolished by section of the spinal cord
at the C3 level and by intravenous administration of bretylium (10 mg/
kg) or phentolamine (5 mg/kg), The response was significantly reduced
by the prior administration of papaverine (10 mg/kg), 3, Functional ad
renalectomy by means of a snare placed around the nerves and blood ves
sels supplying the adrenal glands significantly reduced the response,
Electrical stimulation of the trigeminal ganglion was accompanied by a
fall in circulating levels of noradrenaline and serotonin, 4, We conc
lude that ES of the trigeminal ganglion produces dilatation in the mid
dle meningeal artery partly by autoregulation during the trigeminal de
pressor response and partly by a reduction in the circulating levels o
f noradrenaline. It differs from the dilatation seen in the general ca
rotid circulation and the cortical microcirculation, which is mediated
by parasympathetic nerves, There is no evidence that antidromic relea
se of neuropeptides from sensory nerve endings in the dura plays a par
t in the dilatation.