scholarly journals Selective Electrical Stimulation of Postganglionic Cerebrovascular Parasympathetic Nerve Fibers Originating from the Sphenopalatine Ganglion Enhances Cortical Blood Flow in the Rat

1990 ◽  
Vol 10 (3) ◽  
pp. 383-391 ◽  
Author(s):  
Norihiro Suzuki ◽  
Jan Erik Hardebo ◽  
Jan Kåhrström ◽  
Christer Owman
Keyword(s):  
Blood Flow ◽  
Electrical Stimulation ◽  
Nerve Fibers ◽  
Microvascular Blood Flow ◽  
Sphenopalatine Ganglion ◽  
Flow Measurements ◽  
Parasympathetic Nerve ◽  
Cortical Blood Flow ◽  
Arterial Blood ◽  
Stimulation Of

Recently, the origins and pathways of cerebrovascular acetylcholine- and vasoactive intestinal polypeptide-containing nerves have been elucidated in detail in the rat: The sphenopalatine ganglion is the major source for postganglionic parasympathetic fibers to the vascular beds of the cerebral hemispheres. To clarify the functional role of the nerves on cerebral blood vessels in vivo, brain cortical microvascular blood flow was measured in rats during electrical stimulation of these particular postganglionic fibers. Animals were subjected to transection of the right nasociliary nerve 2 weeks before the flow measurements to eliminate activation of peptidergic sensory fibers. Relative change in microvascular blood flow was continuously recorded by a laser-Doppler flowmeter system under α-chloralose anesthesia. The postganglionic fibers were electrically stimulated just proximal to the ethmoidal foramen by a bipolar platinum electrode (5 V; 0.5 ms; 3, 10, 30, 60 Hz; as a continuous stimulation for 90 s). Stimulation at 10 Hz induced a marked increase of the cortical blood flow (CoBF) on the ipsilateral side, whereas no change was observed on the contralateral side. It reached a maximum mean value of 42.5% at 46 s, and then slightly declined during the remaining stimulation period. No significant changes were observed in the mean arterial blood pressure or blood gases during or after stimulation. Both atropine and scopolamine failed to alter this flow increase. Electrical stimulation of the postganglionic fibers at different frequencies revealed a maximal increase in the CoBF at 30 Hz in the control situation (47.2%), but at 10 Hz after scopolamine administration (51.6%). This provides the first report showing that selective postganglionic stimulation of the parasympathetic nerve fibers markedly enhances blood flow in the brain, and it supports the view that the neurogenic vasodilatation is primarily noncholinergic.

Autoradiographic Evidence for Flow-Metabolism Uncoupling During Stimulation of the Nucleus Basalis of Meynert in the Conscious Rat

1997 ◽  
Vol 17 (6) ◽  
pp. 686-694 ◽  
Author(s):  
Elvire Vaucher ◽  
Josiane Borredon ◽  
Gilles Bonvento ◽  
Jacques Seylaz ◽  
Pierre Lacombe
Keyword(s):  
Blood Flow ◽  
Electrical Stimulation ◽  
Metabolic Activity ◽  
Nucleus Basalis ◽  
Nucleus Basalis Of Meynert ◽  
Conscious Rat ◽  
Local Flow ◽  
Cortical Blood Flow ◽  
Subcortical Regions ◽  
Stimulation Of

We earlier reported that electrical stimulation of the rat nucleus basalis of Meynert (NBM) induces large cerebral blood flow increases, particularly in frontal cortical areas but also in some subcortical regions. The present study was designed to address the issue of blood flow control exerted by NBM projections. To this aim, we have determined whether these flow increases were associated with proportionate changes in metabolic activity as evaluated by cerebral glucose utilization (CGU) strictly under the same experimental conditions in the conscious rat. An electrode was chronically implanted in a reactive site of the NBM as determined by laser-Doppler flowmetry (LDF) of the cortical circulation. One to two weeks later, while the cortical blood flow was monitored by LDF, we measured CGU using the [14C]2-deoxyglucose autoradiographic technique during unilateral electrical stimulation of the NBM, and analyzed the local flow-metabolism relationship. The large increases in cortical blood flow induced by NBM stimulation, exceeding 300% in various frontal areas, were associated with at most 24% increases in CGU (as compared with the control group) in one frontal area. By contrast, strong increases in CGU exceeding 150% were observed in subcortical regions ipsilateral to the stimulation, especially in extrapyramidal structures, associated with proportionate CBF changes. Thus, none of the blood flow changes observed in the cortex can be ascribed to an increased metabolic activity, whereas CBF and CGU were coupled in many subcortical areas. This result indicates that different mechanisms, which do not necessarily involve any metabolic factor, contribute to the regulation of the cerebral circulation at the cortical and subcortical level. Because the distribution of the uncoupling is coincident with that of cholinergic NBM projections directly reaching cortical microvessels, these data strongly support the hypothesis that NBM neurons are capable of exerting a neurogenic control of the cortical microcirculation.

scholarly journals Advantages of imaging photoplethysmography for migraine modeling: new optical markers of trigemino‐vascular activation in rats

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Alexey Y. Sokolov ◽  
Maxim A. Volynsky ◽  
Valery V. Zaytsev ◽  
Anastasiia V. Osipchuk ◽  
Alexei A. Kamshilin
Keyword(s):  
Blood Flow ◽  
Electrical Stimulation ◽  
Imaging System ◽  
Inhibitory Effect ◽  
Trigeminovascular System ◽  
Cranial Window ◽  
Arterial Blood ◽  
Male Wistar Rats ◽  
Optical Markers ◽  
Stimulation Of

Abstract Background Existent animal models of migraine are not without drawbacks and limitations. The aim of our study was to evaluate imaging photoplethysmography (PPG) as a method of assessing intracranial blood flow in rats and its changes in response to electrical stimulation of dural trigeminal afferents. Methods Experiments were carried out with 32 anesthetized adult male Wistar rats. Trigeminovascular system (TVS) was activated by means of electrical stimulation of dural afferents through a closed cranial window (CCW). Parameters of meningeal blood flow were monitored using a PPG imaging system under green illumination with synchronous recording of an electrocardiogram (ECG) and systemic arterial blood pressure (ABP). Two indicators related to blood-flow parameters were assessed: intrinsic optical signals (OIS) and the amplitude of pulsatile component (APC) of the PPG waveform. Moreover, we carried out pharmacological validation of these indicators by determining their sensitivity to anti-migraine drugs: valproic acid and sumatriptan. For statistical analysis the non-parametric tests with post-hoc Bonferroni correction was used. Results Significant increase of both APC and OIS was observed due to CCW electrical stimulation. Compared to saline (n = 11), intravenous administration of both the sumatriptan (n = 11) and valproate (n = 10) by using a cumulative infusion regimen (three steps performed 30 min apart) lead to significant inhibitory effect on the APC response to the stimulation. In contrast, intravenous infusion of any substance or saline did not affect the OIS response to the stimulation. It was found that infusion of either sumatriptan or valproate did not affect the response of ABP or heart rate to the stimulation. Conclusions Imaging PPG can be used in an animal migraine model as a method for contactless assessment of intracranial blood flow. We have identified two new markers of TVS activation, one of which (APC) was pharmacologically confirmed to be associated with migraine. Monitoring of changes in APC caused by CCW electrical stimulation (controlling efficiency of stimulation by OIS) can be considered as a new way to assess the peripheral mechanism of action of anti-migraine interventions.

scholarly journals Inhibition of Nitric Oxide Synthase Attenuates the Cerebral Blood Flow Response to Stimulation of Postganglionic Parasympathetic Nerves in the Rat

1993 ◽  
Vol 13 (6) ◽  
pp. 993-997 ◽  
Author(s):  
Yoko Morita-Tsuzuki ◽  
Jan Erik Hardebo ◽  
Eliete Bouskela
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Systemic Blood Pressure ◽  
High Dose ◽  
Parasympathetic Nerve ◽  
Doppler Flowmetry ◽  
Cortical Blood Flow ◽  
Parasympathetic Nerves ◽  
Flow Response ◽  
Stimulation Of

Stimulation of cerebrovascular parasympathetic nerves markedly increases cortical blood flow. Nitric oxide (NO) or a NO-containing compound is present in these nerves and may therefore, upon release, be partly responsible for the flow increase. In addition, transmitters released from the nerves may cause synthesis and release of this compound from the endothelium. The contribution of NO synthesis to the cortical blood flow (CoBF) increase during parasympathetic stimulation was elucidated in rat by laser–Doppler flowmetry. Thirty-minute exposure to circulating Nω-nitro-l-arginine methyl ester (l-NAME) 50 mg kg−1 eliminated most of the response (from 104 to 8% increase), whereas 10-min exposure to this dose or 30-min exposure to 5 mg kg−1 caused a less marked reduction. The reducing effect was particularly evident after elimination of the systemic blood pressure increase caused by l-NAME (only 3% increase after the high dose). Infusion of l-arginine restored the flow response. Resting CoBF was not substantially affected by blockade of NO formation. Thus, release of an NO-containing compound constitutes a major component of the increase in CoBF caused by parasympathetic nerve stimulation but does not seem to contribute to cortical flow regulation during resting conditions.

Electrical stimulation of postganglionic cranial VIP nerve fibers enhances cerebral blood flow

1989 ◽  
Vol 26 (2) ◽  
pp. 182
Author(s):  
N. Suzuki ◽  
J.E. Hardebo ◽  
J. Kåhrström ◽  
Ch. Owman
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Electrical Stimulation ◽  
Nerve Fibers ◽  
Stimulation Of

scholarly journals Effect of Stimulation of the Sphenopalatine Ganglion on Cortical Blood Flow in the Rat

1988 ◽  
Vol 8 (6) ◽  
pp. 875-878 ◽  
Author(s):  
J. Seylaz ◽  
H Hara ◽  
E. Pinard ◽  
S. Mraovitch ◽  
E. T. MacKenzie ◽  
...  
Keyword(s):  
Blood Flow ◽  
Parietal Cortex ◽  
Sphenopalatine Ganglion ◽  
Cerebral Blood Vessels ◽  
Cortical Blood Flow ◽  
Partial Pressures ◽  
Cortical Electrical Activity ◽  
Rat Tissue ◽  
Parietal Cortices ◽  
Stimulation Of

The effects of electrical stimulation of the sphenopalatine ganglion on cortical blood flow and gas partial pressures (Po2 and PCo2) were studied in the anesthetized rat. Tissue Po2, PCo2, and local CBF were measured simultaneously in both parietal cortices by means of mass spectrometry. Stimulation of the sphenopalatine ganglion increased CBF and tissue Po2 by —50 and 20%, respectively, in the ipsilateral parietal cortex. Smaller but significant increases in CBF and tissue Po2 were simultaneously seen in the contralateral parietal cortex. These variations were also accompanied by small decreases in PCo2 in both parietal cortices and a 5% increase in mean arterial pressure, whereas cortical electrical activity did not change. We conclude that the cholinergic (and vasoactive intestinal polypeptidergic) innervation of the cerebral blood vessels, arising from the sphenopalatine ganglion has significant vasomotor potential and that this system may be of functional importance.

Reflex effects of upper airway irritation on total lung resistance and blood pressure

1962 ◽  
Vol 17 (6) ◽  
pp. 861-865 ◽  
Author(s):  
Jay A. Nadel ◽  
John G. Widdicombe
Keyword(s):  
Blood Pressure ◽  
Nerve Fibers ◽  
Parasympathetic Nerve ◽  
Arterial Blood ◽  
Laryngeal Mucosa ◽  
Lung Resistance ◽  
Decerebrate Cats ◽  
Total Lung Resistance ◽  
Mechanical Irritation ◽  
Stimulation Of

Mechanical irritation of the laryngeal mucosa reflexly increased total lung resistance distal to the larynx in cats anesthetized with chloralose and urethan and in decerebrate cats. The afferent limb of the reflex is in the superior laryngeal and the efferent limb in the vagus nerves. Stimulation of the larynx also increased activity in efferent parasympathetic nerve fibers going to the trachea and bronchi. Mechanical irritation of the nasal mucosa did not change total lung resistance. Stimulation of the nares or larynx increased arterial blood pressure conspicuously in decerebrate cats but only slightly in cats anesthetized with chloralose and urethan. The efferent path of the hypertensive response is in the sympathetic nerves, the afferent path for the nasal effect is in the fifth cranial nerves, and the afferent path for the laryngeal effect is in the superior laryngeal nerves. Submitted on March 6, 1962

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