A role of the central catecholamine neuron in cerebral circulation

✓ The effect of the central catecholaminergic neurons on the cerebral microcirculation was investigated by means of a unilateral intracerebral injection of 6-hydroxydopamine (6-OHDA) which produced the degeneration of catecholamine (CA) nerve terminals. Subsequent observation with CA histofluorescence revealed an absence of CA fibers in the vicinity of the 6-OHDA injection site. A significant increase in regional cerebral blood flow (rCBF), measured by the hydrogen clearance method, was demonstrated in the CA-depleted cortex under normocapnia as compared with rCBF in the control cortex (CA-depleted cortex 47.0 ± 2.8 ml/100 gm/min; control cortex 38.5 ± 3.5 ml/100 gm/min; p < 0.005). The increased rCBF in the cortex treated with 6-OHDA was suppressed by the iontophoretic replacement of noradrenaline (NA) to the CA-depleted cortex. An iontophoretic replacement of 10−5 M dopamine (DA) mildly suppressed the increased rCBF in the 6-OHDA-treated cortex. The CO2 reactivity in the CA-depleted cortex was significantly lower than that of the control cortex (CA-depleted cortex 2.13% ± 0.67%/mm Hg; control cortex 3.53% ± 0.70%/mm Hg). No change was noticeable in the cerebral glucose metabolism in the CA-depleted cortex in an investigation based on tritiated (3H)-deoxyglucose uptake. It is suggested that the 6-OHDA-induced change in cerebral blood flow (CBF) is not secondary to alterations in cerebral metabolic rate, and that the central NA neuron system innervating intraparenchymal blood vessels regulates CBF through a direct vasoconstrictive effect on the cerebral blood vessels. The central DA neuron system may modulate the cerebral circulation as a mild vasoconstrictor.

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Effect of chemical sympathectomy on cerebral blood flow in rats

Journal of Neurosurgery ◽

10.3171/jns.1991.75.6.0906 ◽

1991 ◽

Vol 75 (6) ◽

pp. 906-910 ◽

Cited By ~ 16

Author(s):

Hidenori Kobayashi ◽

Minoru Hayashi ◽

Hirokazu Kawano ◽

Yuji Handa ◽

Masanori Kabuto ◽

...

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Systemic Blood Pressure ◽

Treated Group ◽

Control Group ◽

Electron Microscopic ◽

Content Type ◽

Left Lateral Ventricle ◽

6 Hydroxydopamine ◽

Fine Print

✓ Thirty male Wistar rats, weighing 350 to 400 gm each, received stereotactic injections of 6-hydroxydopamine (300 µg/kg) into the left lateral ventricle. The same amount of saline was injected into a control group of 15 rats. Seven days after this procedure, cerebral blood flow (CBF) was measured by the hydrogen clearance method. A hypertensive condition at a mean arterial pressure of about 160 mm Hg was maintained for 1 hour by intravenous infusion of phenylephrine. In the 6-hydroxydopamine-treated group, CBF increased significantly after the elevation of systemic blood pressure compared with that in the control group, and cerebral autoregulation was impaired. After a 1-hour study, the specific gravity of the cerebral tissue in the treated group significantly decreased; electron microscopic studies at that time revealed brain edema. It is suggested that depletion of brain noradrenaline levels causes a disturbance in cerebral microvascular tone and renders the cerebral blood vessels more vulnerable to hypertension.

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Regulation of rCBF by intracortical vasoactive intestinal polypeptide-containing neurons

Journal of Neurosurgery ◽

10.3171/jns.1987.67.1.0093 ◽

1987 ◽

Vol 67 (1) ◽

pp. 93-96 ◽

Cited By ~ 7

Author(s):

Toru Itakura ◽

Hideyoshi Yokote ◽

Takashi Okuno ◽

Yutaka Naka ◽

Kazuo Nakakita ◽

...

Keyword(s):

Blood Flow ◽

Blood Vessels ◽

Vasoactive Intestinal Polypeptide ◽

Content Type ◽

Intimate Association ◽

The Mean ◽

Immunohistochemical Studies ◽

Hydrogen Clearance ◽

Intestinal Polypeptide

✓ The role of intracortical vasoactive intestinal polypeptide (VIP)-containing neurons in the regulation of cortical blood flow was investigated in rats by immunohistochemical and hydrogen clearance methods. Immunohistochemical studies revealed an intimate association between intracortical VIP-containing neurons and small blood vessels. Intracortical injection of a VIP solution (10−5 M) produced significantly higher blood flow in the treated cortex (mean ± standard error of the mean: 46.2 ± 4.0 ml/100 gm/min) than in the untreated cortex (36.9 ± 2.4 ml/100 gm/min). These data suggest that intracortical VIP-containing neurons produce dilatation of intracortical blood vessels.

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Nitric oxide mediation of chemoregulation but not autoregulation of cerebral blood flow in primates

Journal of Neurosurgery ◽

10.3171/jns.1996.84.1.0071 ◽

1996 ◽

Vol 84 (1) ◽

pp. 71-78 ◽

Cited By ~ 80

Author(s):

B. Gregory Thompson ◽

Ryszard M. Pluta ◽

Mary E. Girton ◽

Edward H. Oldfield

Keyword(s):

Nitric Oxide ◽

Blood Flow ◽

Cerebral Blood Flow ◽

No Production ◽

Direct Role ◽

Content Type ◽

Continuous Release ◽

Fine Print

✓ The authors sought to develop a model for assessing in vivo regulation of cerebral vasoregulation by nitric oxide (NO), originally described as endothelial-derived relaxing factor, and to use this model to establish the role of NO in the regulation of cerebral blood flow (CBF) in primates. By using regional intraarterial perfusion, the function of NO in cerebral vasoregulation was examined without producing confounding systemic physiological effects. Issues examined were: whether resting vasomotor tone requires NO; whether NO mediates vasodilation during chemoregulation and autoregulation of CBF; and whether there is a relationship between the degree of hypercapnia and hypotension and NO production. Twelve anesthetized (0.5% isoflurane) cynomolgus monkeys were monitored continuously for cortical CBF, PaCO2, and mean arterial pressure (MAP), which were systematically altered to provide control and experimental curves of chemoregulation (CBF vs. PaCO2) and autoregulation (CBF vs. MAP) during continuous intracarotid infusion of 1) saline and 2) an NO synthase inhibitor (NOSI), either l-n-monomethyl arginine or nitro l-arginine. During basal conditions (PaCO2 of 38–42 mm Hg) NOSI infusion of internal carotid artery (ICA) reduced cortical CBF from 62 (saline) to 53 ml/100 g/per minute (p < 0.01), although there was no effect on MAP. Increased CBF in response to hypercapnia was completely blocked by ICA NOSI. The difference in regional (r)CBF between ICA saline and NOSI infusion increased linearly with PaCO2 when PaCO2 was greater than 40 mm Hg, indicating a graded relationship of NO production, increasing PaCO2, and increasing CBF. Diminution of CBF with NOSI infusion was reversed by simultaneous ICA infusion of l-arginine, indicating a direct role of NO synthesis in the chemoregulation of CBF. Hypotension and hypertension were induced with trimethaphan camsylate (Arfonad) and phenylephrine at constant PaCO2 (40 ± 1 mm Hg). Autoregulation in response to changes in MAP from 50 to 140 mm Hg was unaffected by ICA infusion of NOSI. In primates, cerebral vascular tone is modulated in vivo by NO; continuous release of NO is necessary to maintain homeostatic cerebral vasodilation; vasodilation during chemoregulation of CBF is mediated directly by NO production; autoregulatory vasodilation with hypotension is not mediated by NO; and increasing PaCO2 induces increased NO production.

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Functional Bases for a Central Serotonergic Involvement in Classic Migraine: A Speculative View

Cephalalgia ◽

10.1046/j.1468-2982.1985.0502069.x ◽

1985 ◽

Vol 5 (2) ◽

pp. 69-78 ◽

Cited By ~ 21

Author(s):

ET MacKenzie ◽

L Edvinsson ◽

B Scatton

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Migraine Attack ◽

Blood Vessels ◽

Blood Brain Barrier ◽

Plasma Levels ◽

Cerebral Blood Vessels ◽

Large Arteries ◽

The Subject

The rôle of serotonin (5-HT) in the cerebrovascular bed is the subject of the following review. Cerebral blood vessels are supplied with 5-HT-containing fibres which originate in the raphé nuclei in the brainstem. The activation of this system may result in a constriction of large arteries and a dilatation of arterioles. Intra-arterial administration of 5-HT causes reduction in cerebral blood flow and metabolism provided it bypasses the blood-brain barrier. The findings, marked changes in plasma levels of 5-HT and in cerebral blood flow during a classic migraine attack, are suggestive of an involvement of the 5-HT system.

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Cerebral circulation and metabolism after severe traumatic brain injury: the elusive role of ischemia

Journal of Neurosurgery ◽

10.3171/jns.1991.75.5.0685 ◽

1991 ◽

Vol 75 (5) ◽

pp. 685-693 ◽

Cited By ~ 561

Author(s):

Gerrit J. Bouma ◽

J. Paul Muizelaar ◽

Sung C. Choi ◽

Pauline G. Newlon ◽

Harold F. Young

Keyword(s):

Traumatic Brain Injury ◽

Blood Flow ◽

Cerebral Blood Flow ◽

Brain Injury ◽

Neurological Status ◽

Content Type ◽

Head Injured ◽

Adult Head ◽

Injured Patients

✓ Although experimental and pathological studies suggest an important role for ischemia in the majority of fatal cases of traumatic brain injury, ischemia has been a rare finding in most clinical studies of cerebral blood flow (CBF) in head-injured patients. The hypothesis of the present study was that cerebral ischemia occurs in the first few hours after injury, but that CBF measurements have not been performed early enough. Early measurements of CBF (by the 133Xe intravenous method) and arteriovenous oxygen difference (AVDO2) were obtained in 186 adult head-injured patients with a Glasgow Coma Scale score of 8 or less, and were correlated with neurological status and outcome. During the first 6 hours after injury, CBF was low (22.5 ± 5.2 ml/100 gm/min) but increased significantly during the first 24 hours. The AVDO2 followed the opposite course; the decline of AVDO2 was most profound in patients with low motor scores, suggesting relative hyperemia after 24 hours. A significant correlation between motor score and CBF was found in the first 8 hours after injury (Spearman coefficient = 0.69, p < 0.001), but as early as 12 hours postinjury this correlation was lost. A similar pattern was found for the relationship between CBF and outcome. Cerebral blood flow below the threshold for infarction (CBF ≤ 18 ml/100 gm/min) was found in one-third of the studies obtained within 6 hours, the incidence rapidly decreasing thereafter. A low CBF after 24 hours was not generally associated with a high AVDO2, and was probably a reflection of low oxidative metabolism rather than frank ischemia. In 24 patients, a CBF of 18 ml/100 gm/min or less was found at some point after injury; the mortality rate was significantly higher in this subgroup, and survivors did worse. In some cases, ischemia was successfully treated by reducing hyperventilation or inducing arterial hypertension. These results support the above hypothesis, and suggest that early ischemia after traumatic brain injury may be an important factor determining neurological outcome. Moreover, these data indicate that early hyperventilation or lowering of blood pressure to prevent brain edema may be harmful.

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5-Hydroxytryptamine innervation of vessels in the rat cerebral cortex

Journal of Neurosurgery ◽

10.3171/jns.1985.62.1.0042 ◽

1985 ◽

Vol 62 (1) ◽

pp. 42-47 ◽

Cited By ~ 25

Author(s):

Toru Itakura ◽

Hideyoshi Yokote ◽

Hiroshi Kimura ◽

Ichiro Kamei ◽

Kazuo Nakakita ◽

...

Keyword(s):

Blood Vessels ◽

Nerve Fibers ◽

Ultrastructural Observation ◽

Intracerebral Injection ◽

Neuron System ◽

Content Type ◽

Carbon Dioxide Reactivity ◽

Immunohistochemical Techniques ◽

Immunohistochemical Studies ◽

Hydrogen Clearance

✓ The role of the central 5-hydroxytryptamine (5-HT) neuron system in cerebral microcirculation of the rat was examined by immunohistochemical and hydrogen clearance methods. Immunohistochemical studies demonstrated 5-HT-immunoreactive nerve fibers along intraparenchymal blood vessels (arterioles, capillaries, and venules). Ultrastructural observation revealed that 5-HT-immunoreactive terminal boutons (0.3 to 1.0 µm in diameter) made contact with the basement membrane of the capillaries. After an intracerebral injection of 5,7-dihydroxytryptamine (5,7-DHT), a neurotoxin to the 5-HT neuron system, no 5-HT-immunoreactive nerve fibers were found around the injection site with immunohistochemical techniques. With the hydrogen clearance method, the 5,7-DHT-injected cortex showed no significant change in regional cerebral blood flow (rCBF) in the presence of normocapnia, but a significant increase in rCBF with hypercapnia, compared with the untreated cortex. These facts strongly suggest that the central 5-HT neuron system has an important role in carbon dioxide reactivity of the cerebral blood vessels.

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The role of adenosine in the regulation of cerebral blood flow: antagonistic effects of theophylline, an adenosine receptor blocker, on adenosine- and hypoxia-induced vasodilation of rat cerebral microvessels

The Japanese Journal of Pharmacology ◽

10.1016/s0021-5198(19)58912-0 ◽

1986 ◽

Vol 40 ◽

pp. 31

Author(s):

Seiji Morii ◽

Al C. Ngai ◽

H. Richard Winn

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Adenosine Receptor ◽

Receptor Blocker ◽

Cerebral Microvessels ◽

Antagonistic Effects

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Sound Richness of Music Might Be Mediated by Color Perception: A PET Study

Behavioural Neurology ◽

10.1155/2015/241804 ◽

2015 ◽

Vol 2015 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Masayuki Satoh ◽

Ken Nagata ◽

Hidekazu Tomimoto

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Multisensory Integration ◽

Regional Cerebral Blood Flow ◽

Traditional Music ◽

Simple Condition ◽

Regional Cerebral Blood ◽

Subtraction Technique ◽

Posterior Portion

Objects. We investigated the role of the fusiform cortex in music processing with the use of PET, focusing on the perception of sound richness.Method. Musically naïve subjects listened to familiar melodies with three kinds of accompaniments: (i) an accompaniment composed of only three basic chords (chord condition), (ii) a simple accompaniment typically used in traditional music text books in elementary school (simple condition), and (iii) an accompaniment with rich and flowery sounds composed by a professional composer (complex condition). Using a PET subtraction technique, we studied changes in regional cerebral blood flow (rCBF) in simple minus chord, complex minus simple, and complex minus chord conditions.Results. The simple minus chord, complex minus simple, and complex minus chord conditions regularly showed increases in rCBF at the posterior portion of the inferior temporal gyrus, including the LOC and fusiform gyrus.Conclusions. We may conclude that certain association cortices such as the LOC and the fusiform cortex may represent centers of multisensory integration, with foreground and background segregation occurring at the LOC level and the recognition of richness and floweriness of stimuli occurring in the fusiform cortex, both in terms of vision and audition.

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The Role of Electrode Size on the Incidence of Spreading Depression and on Cortical Cerebral Blood Flow as Measured by H2 Clearance

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.1992.33 ◽

1992 ◽

Vol 12 (2) ◽

pp. 230-237 ◽

Cited By ~ 37

Author(s):

Marleen J. Verhaegen ◽

Michael M. Todd ◽

David S. Warner ◽

Bruce James ◽

Julie B. Weeks

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Gray Matter ◽

Spreading Depression ◽

Insertion Depth ◽

Flow Measurements ◽

Electrode Size ◽

Cortical Gray Matter ◽

The Right

Cerebral blood flow was measured by the H2 clearance method 30 and 60 min after the implantation of 300, 250, 125, or 50 μm diameter platinum–iridium electrodes 2 mm deep into the right parietal cortex of normothermic, normocarbic halothane-anesthetized rats. Another group of animals had 50 μm electrodes inserted 1 mm. In all animals, the presence or absence of a wave of spreading depression (SD) was noted at the time of implantation, with recordings made with glass micropipettes. H2 flow values were compared with those measured in gray matter from the same anatomical region (but from different rats), using [3H]nicotine. The incidence of SD ranged from 60% following insertion of 300 μm electrodes to 0% with 50 μm electrodes. H2 clearance flows also varied with electrode size, from 77 ± 21 ml 100 g−1 min−1 (mean ± standard deviation) with 300 μm electrodes to 110 ± 31 and 111 ± 16 ml 100 g−1 min−1 with 125 and 50 μm electrodes, respectively (insertion depth of 2 mm). A CBF value of 155 ± 60 ml 100 g−1 min−1 was obtained with 50 μm electrodes inserted only 1 mm. Cortical gray matter blood flow measured with [3H]nicotine was 154 ± 35 ml 100 g−1 min−1. When the role of SD in subsequent flow measurements was examined, there was a gradual increase in CBF between 30 and 60 min after electrode insertion in those animals with SD, while no such change was seen in rats without SD. These results indicate that the choice of electrode size and implantation depth influences the measurement of CBF by H2 clearance. CBF values equivalent to those obtained with isotopic techniques can be acutely obtained with small (50 μm diameter) electrodes inserted 1 mm into the cortex. While the occurrence of SD does influence CBF in the period immediately after implantation, a relationship between electrode size and measured flow is present that is independent of SD.

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