A histochemical study of the innervation of cerebral blood vessels in the snake

Dual innervation of snake cerebral blood vessels by adrenergic and cholinergic fibres was demonstrated with the use of histochemical methods. Although the nerve plexuses are somewhat less dense, the essential features of innervation of the blood vessels are similar to those of mammals with the exception that the adrenergic plexuses are more prominent than the cholinergic plexuses. The major arteries of the cerebral carotid system have a rich nerve supply. However, the innervation is less rich in the basilar and poor in the spinal (vertebral) arteries. Although the arteries supplying the right side of head are poorly developed, three pairs of arteries, cerebral carotids, ophthalmics and spinals, supply the snake brain. The carotids and ophthalmics are densely innervated and are accompanied by thick nerve bundles, suggesting that the nerves preferentially enter the skull along those arteries. Some parenchymal arterioles are also dually innervated. Connection between the brain parenchyma and intracerebral capillaries via both cholinergic and adrenergic fibres was observed. In addition cholinergic nerve fibers, connecting capillaries and the intramedullary nerve fibre bundles, were noticed. Capillary blood flow may be influenced by both adrenergic and cholinergic central neurons. The walls of capillaries also exhibit heavy acetylcholinesterase activity. This may indicate an important role for the capillary in the regulation of intracerebral blood flow.     

An ethical responsibility for pain management

Recently, neuronal nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase has been elucidated to be the nitric oxide synthase (NOS) per se. In order to examine the existence and distribution of cerebrovascular nerve fibers containing these substances, NADPH-diaphorase histochemistry was applied to the cerebral blood vessels and the cranial ganglia known to innervate the cerebral vessels in the rat. Numerous nerve fibers with varicosities forming plexuses were observed in the circle of Willis and its branches. In addition, thick nerve bundles were seen to run along the wall of the internal ethmoidal artery. NADPH-diaphorase reaction was prominent in neurons of the sphenopalatine, otic and internal carotid ganglia. This study demonstrated, for the first time, the NADPH-diaphorase-containing nerve fibers in the cerebral vessels and ganglion cells in the parasympathetic and sensory ganglia known to innervate the cerebral vessels.     

Histophysiologic characteristics of the effector innervation of the arteries of the base of the brain during rat ontogenesis

The development of adren- and cholinergic nervous plexuses in the brain base arteries was studied by histochemical methods of Falck and Kelle in animals and fetuses of 10-22 days, newborn rats, animals of 10, 20, 30, 40, 60 and 120 days of life and 1 and 2 years old rats. The cholinergic nerve fibres were first found in the basilar, vertebral and internal carotid arteries on the 15th and 16th days of ontogenesis. Specific fluorescence of adrenergic conductors on the same arteries is revealed somewhat later--from the 17th and 18th days of the intrauterine development. Further formation of the cholin- and adrenergic innervation of the arteries of the Willis' circle goes on synchronously. The number of nerve fibres increases with the growth of the artery diameter. The concentration of catecholamines and the activity of AChE in them gradually increases. The greatest density of nerve fibres per 1 mm2 is determined in 20-day-old rats. The number of cholinergic nerve fibres on the arteries of the brain base is equal to that of adrenergic fibres during the whole period of postnatal ontogenesis. By the 30th day the effector nervous apparatus has a definite structure. In old rats the activity of AChE and the content of catecholamines drop, the amount and concentration of nerve fibres decrease.     

Reduction of regional cerebral blood flow by melatonin in young rats

Melatonin (10 ng) was subcutaneously administered to 14-day-old Sprague-Dawley rats. Regional blood flow (rCBF) was measured in 22 anatomically defined structures 20 min later using iodo[14C]antipyrine and quantitative autoradiography. rCBF was markedly reduced in the cerebral areas supplied by circle of Willis and the basilar arteries. Melatonin also significantly decreased blood flow to choroid plexuses. These findings suggest that circulating melatonin may contribute to regulation of cerebral blood flow and brain fluid balance.     

Hemorrhagic infarct of the brain during cardiogenic shock]

The paper deals with the possible mechanism in the development of a hemorrhagic brain infarction during myocardial infarction, complicated by a cardiogenic shock of the III degree. The results of a postmortal study of the brain, its major arteries, as well as the vessels of the Willis circle, permit to assume that the mechanism of realization of this cerebral vascular complication is in a joint metabolic and microcirculatory disorders accompanying the shock. Besides, there is also a stenosing atherosclerotic process, with prevalent lesion of the intracranial part of the magistral arteries, supplying the brain.     

Cerebrovascular ultrasound diagnosis

Introduction of color-coded duplex sonography has further increased diagnostic confidence of neurovascular ultrasound. Thus, reliable and noninvasive preoperative assessment of patients with carotid artery stenoses becomes feasible, preventing potential adverse effects of cerebral angiography. Moreover, reliable diagnosis of subtotal stenoses and occlusions of the carotid arteries is possible. Transcranial ultrasonography provides reliable assessment of cross-flow through the circle of Willis, and stenoses, occlusions and vasospasm of the major basal cerebral arteries. Transcranial color-coded duplex sonography identifies intracranial hemorrhage, cerebrovascular malformations and hydrocephalus but is inferior to neuroradiological techniques. It is likely that power Doppler sonography and transpulmonary contrast agents will provide an additional increase in diagnostic confidence of neurovascular ultrasonography. In the future, cerebral microemboli may become a marker for embolic activity of occlusive carotid artery and cardiac disease.     

Epidemiological studies of cerebro-and cardiovascular diseases in the northeast of Japan Part I. Pathological approach to the study in Akita Prefecture

To define the etiologic factors of Japanese cerebrovascular diseases, a pathological research was conducted on autopsy cases of stroke in Akita Prefecture. In most cases of cerebral hemorrhages, especially in the middle age group (30-59 of age), arteriosclerotic deviations in basal berebral arteries of the circle of Willis and intracerebral small arteries are not found. The authors conclude that cerebral hemorrhage may occur without relationship to disturbances of lipid metabolism, biochemically, and to atherosclerosis, pathologically. Concerning cerebral infarction, especially in the old generation (over 60 years of age), severe arteriosclerotic deviations were recognized both in basal cerebral and intracerebral arteries. These changes were highly influenced by the grade and duration of hypertension, and rarely influenced by hypercholesterolemia. According to the above-mentioned facts, the results obtained from out epidemiological survey were confirmed by the pathological studies.     

Neuronal nitric oxide synthase activation by vasoactive intestinal peptide in bovine cerebral arteries

The participation of nitric oxide and vasoactive intestinal peptide (VIP) in the neurogenic regulation of bovine cerebral arteries was investigated. Nitrergic nerve fibers and ganglion-like groups of neurons were revealed by NADPH-diaphorase staining in the adventitial layer of bovine cerebral arteries. NADPH diaphorase also was present in endothelial cells but not in the smooth muscle layer. Double immunolabeling for neuronal nitric oxide synthase and VIP indicated that both molecules co-localized in the same nerve fibers in these vessels. Transmural nerve stimulation (200 mA, 0.2 milliseconds, 1 to 8 Hz) of endothelium-denuded bovine cerebral artery rings precontracted with prostaglandin F2 alpha, produced tetrodotoxin-sensitive relaxations that were completely suppressed by NG-nitro-L-arginine methyl ester (L-NAME) and by the guanylyl cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline (ODQ), but were not affected by the adenylyl cyclase inhibitor 9-(tetrahydro-2-furanyl)-9H-purin-6-amine (SQ 22,536), nor by VIP tachyphylaxis induced by pretreatment with 1 mumol/L VIP. Transmural nerve stimulation also elicited increases in intracellular cyclic GMP concentration, which were prevented by L-NAME, and small decreases in intracellular cyclic AMP concentration. Addition of VIP to bovine cerebral artery rings without endothelium produced a concentration-dependent relaxation that was partially inhibited by L-NAME, ODQ, and SQ 22,536. The effects of L-NAME and SQ 22,536 were additive. VIP induced a transient increase in intracellular cyclic GMP concentration, which was maximal 1 minute after VIP addition, when the highest relaxation rate was observed, and which was blocked by L-NAME. It is concluded that nitric oxide produced by perivascular neurons and nerve fibers fully accounts for the experimental neurogenic relaxation of bovine cerebral arteries and that VIP, which also is present in the same perivascular fibers, acts as a neuromodulator by activating neuronal nitric oxide synthase.     

Melatonin receptors mediate contraction of a rat cerebral artery

Melatonin receptors are expressed in the cerebral arteries of the rat which form the circle of Willis. We report here that melatonin induces contraction of in vitro preparations of pressurized rat posterior communicating artery, in a concentration-dependent manner. This action of melatonin is inhibited by S-20928, a specific melatonin receptor antagonist. Our results demonstrate that the contractile action of melatonin is mediated by its receptors in the cerebral artery, and suggest a role for melatonin in the regulation of cerebral circulation.     

Automic innervation of dog coronary arteries

The autonomic innervation of canine coronary arteries has been examined using the Falck and Owman technique for demonstrating catecholamines and a modification of the Koelle technique for the demonstration of cholinesterase. The experimental protocol included an examination of the neural innervation of the major coronary arteries: LCC, LAD, and RCA. A consistent, relatively dense adrenergic innervation was noted. A gradient in the degree of cholinergic innervation was: LAD less than RCA less than LCC. Light microscopic examination of the hearts of dogs subjected to either cervical vagotomy or total extrinsic cardiac denervation was performed. Additional surgical procedures included removal of the left stellate ganglion and a preferential stripping of the LCC. These studies demonstrated the intrinsic nature of parasympathetic coronary innervation. Following all surgical procedure no variations in density of cholinergic innervation were noted, indicating that these fibers are probably postganglionic parasympathetic fibers arising from intrinsic ganglia within the ventricles. These ganglia may be located at the base of the great vessels and send their fibers to the coronary vessels via the septal artery.     

Distribution of nitric oxide synthase in the esophagus of the cat and monkey

The distribution of nitrergic neurons and processes in the esophagus of the cat and monkey was studied by light microscopic immunocytochemistry using a specific antibody against purified rat brain nitric oxide synthase and immunoperoxidase procedures. Immunoreactive nerve fibers were found pervading the myenteric plexus, submucous plexus and plexus of the muscularis mucosae, and particularly in the lower esophagus a few immunoreactive fibers entered the epithelium as free nerve endings, some of which derived from perivascular fibers. In the upper esophagus immunoreactive motor end-plates were found in the striated muscle. Thirty-forty-five percent of neuronal cell bodies found in the intramural ganglia and along the course of nerve fiber bundles were immunoreactive and were of the three morphological types earlier described. In the intramural ganglia immunoreactive nerve fibers formed a plexus in which varicose nerve terminals were in close relation to immunoreactive and non-immunoreactive neurons. The intramural blood vessels that crossed the different layers of the esophageal wall were surrounded by paravascular and perivascular plexuses containing immunoreactive nerve fibers. The anatomical findings suggest that nitric oxide is involved in neural communication and in the control of peristalsis and vascular tone in the esophagus. In the lower esophagus a few nitrergic nerve fibers are anatomically disposed to subserve a sensory-motor function.     

Histochemical demonstration of neuronal nitric oxide synthase during development of mouse respiratory tract

Several studies, including histochemical ones, have indicated that nitric oxide (NO) of endothelial origin may be related to the pulmonary vasodilation that occurs at birth. Since no histologic studies have been done of the possible parallel perinatal increase in production of neuronal NO synthase (nNOS) by pulmonary nerve plexuses, we investigated the distribution of nNOS in fetal, neonatal, and adult mouse lung. Lungs from mice aged 13 d gestation to 6 d after birth and lungs of adults were studied through histochemistry for nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) activity and immunocytochemistry. Both techniques gave almost similar results in relation to time of appearance, distribution, and frequency of neural structures positive for NADPH-d and NOS. NADPH-d staining was also applied to whole mounts of developing and adult tracheae. Staining was found from gestational days 13 to 15 onward in a small portion of the neuronal population. In all stages studied, NADPH-d/NOS staining was found in neuron cell bodies in the hilar region and bronchiolar wall, as well as in neuronal processes. Labeled terminal nerve fibers with varicosities were more frequent in pulmonary blood vessels than in airways. In tracheae, similar NADPH-d/NOS-positive nerve plexuses were found. The presence of nNOS in fetal and neonatal mouse respiratory tract suggests that neurally derived NO must play a role in developing lung physiology. However, because no perinatal increase in the number or intensity of staining of nNOS-positive nerve structures was seen, no apparent relation between neural NO and vasodilation can be established at birth.     

Cerebral hemorrhage in Sneddon syndrome

INTRODUCTION: Sneddon syndrome is the association of livedo retricularis and cerebrovascular lesions. It is a vasculopathy of vessels of small and medium calibre which affects young people and is of unknown origin. It is often associated with arterial hypertension and repeated ischemic cerebrovascular accidents which lead to intellectual deterioration. CLINICAL CASE: We describe a 49 year old man who, from the age of 23, had had repeated transient or established episodes compatible with ischemic cerebrovascular accidents. These were followed by various neurological sequelae and by intellectual deterioration. Finally he died of a cerebral hemorrhage whilst on anticoagulant treatment with Synthron. We show the neuroimaging findings (CT, MR and angiography) and the neuropathological studies (cerebral hemorrhage, fibrosis of the intima of the vessels of the circle of Willis, absence of inflammation, bilateral unsymmetrical leukoencephalopathy of the cerebral hemispheres and multiple cortical infarcts). CONCLUSION: We wish to draw attention to the occurrence of this complication, its possible relationship to the vasculopathy mentioned, bursting of one of the arteries of the revascularization complex, arterial hypertension or anticoagulant treatment, and also to add one more case to the few described as having hemorrhage and neuropathology in Sneddon syndrome.     

Nervous apparatus of the walls of the celiac trunk and its branches in man

The impregnation methods in total laminated preparations and histological sections were used to study the nervous apparatus of the celiac trunk and its branches in humans of either sex and different age. It consists of milti- and unipolar cells, periadventitial, adventitial and muscular nervous plexuses, separate nerve trunks and plexuses and single myelinated and non-myelinated nerve fibres terminating with non-encapsulated and encapsulated nerve endings.     

Adrenergic innervation of the cerebral arteries following changes in the activity of cholinergic and monoaminergic brain systems

Bipolar electrical nerve stimulation decreased the adrenergic innervation density and the catecholamine content in the rat isolated caudal artery. Changes in cholinesterase activity and catecholamine content in histochemically active nerves following administration of cholinesterase (AChE) inhibiting agent phosphacol, seem to reflect compensatory responses to increasing dilatory cholinergic vasomotor effects under conditions of the AChE activity. Adrenergic innervation of cerebral arteries was also studied after a 1-hr daily hypoxic sessions. These decreased the catecholamines content as compared to the control.     

Meningeal carcinomatosis

An anatomopathologic study of 18 cases of pure meningeal carcinomatosis is presented. In five of these cases, the brain, spinal cord, choroid plexuses, cerebral vessels, and prevertebral soft tissues, including the lumbosacral nerve plexuses and ganglia, were examined microscopically in an attmept to determine the routes of tumor spread. Our results suggest that the malignant cells reach the cerebrospinal leptomeninges via perineural, endoneural, and perivascular lymphatics and sheaths through the intervertebral and possibly cranial foramina. Involvement of the choroid plexuses appears to be secondary to, rather than the avenue for, leptomeningeal carcinomatosis, with the tumor cells reaching the choroid plexuses via the perivascular sheaths of choroidal vessels. Leptomeningeal carcinomatosis was the only manifestation of metastatic spread beyond regional lymph nodes in about 40% of all reported cases in which this information is available. This implies that radiation or other forms of local therapy to the cerebrospinal leptomeninges may provide an effective means of palliation in many of these cases.     

Manipulation of knee extensor force using percutaneous electrical myostimulation during eccentric actions: effects on indices of muscle damage in humans

In Hirschsprung's disease (HD), certain intestinal nervous plexuses are absent. Sprouting nerve endings contain different amounts of synaptophysin (SY), a protein and main constituent of acetylcholinesterase (AChE) storage compartments. Due to the lack of specific markers for synapses, a qualitative analysis of nerve endings of intestinal segments affected by HD has not yet been undertaken. For this study, resected colorectal specimens from patients with HD (n = 8, mean age 2.1 years) were investigated in parallel for AChE, SY, and content of small synaptic vesicles by biochemical, immunohistochemical, and electronmicroscopic means. In the microdissected muscular layer, reduced SY (1.4 microgram/mg total protein, normal 24 +/- 0.3) was observed. Immunohistochemistry showed in affected tissues reduced numbers of SY-positive nerve fibers and nerve endings, which in turn were thickened and distorted, in both the muscle proper and the muscularis mucosae. Combining both morphologic and biochemical findings, in HD the number of cholinergic vesicles in the remaining nerve endings seems to be increased as measured by SY, a marker molecule specific for synaptic vesicles. Our data also suggest that nerve endings in HD may contain high concentrations of cholinergic vesicles, paralleling the known high amounts of acetylcholine and AChE found in intestinal segments of patients with HD.     

Innervation of cholinergic vestibular efferent system in vestibular periphery of rats

The innervation of cholinergic efferent fibers in the vestibular endorgans of the rats was investigated using a modified preembedding immunostaining technique of immunoelectron microscopy. A monoclonal antibody to choline acetyltransferase (ChAT) was used as a marker of cholinergic fibers. It was found that there were four types of cholinergic innervation in the vestibular endorgans of the rat: (1) cholinergic nerve endings formed axo-dendritic synapses with afferent chalice surrounding the type I sensory hair cells; (2) cholinergic nerve endings formed axo-somatic synapses with type II hair cells; (3) cholinergic fibers synapse with afferent nerve fibers and (4) a synaptic contact developed between cholinergic nerve endings. The results demonstrated that a multiform innervation of the cholinergic efferents exists in the rats vestibular periphery.     

Use of intravenous contrast material in transcranial sonography

RATIONALE AND OBJECTIVES: The appearance of the intracranial vasculature was compared on power and color Doppler ultrasound (US) scans obtained with and without a microbubble contrast agent. MATERIALS AND METHODS: Nine patients (three men, six women) aged 42-70 years (mean age, 53 years) participated in the study. Seven patients underwent both color Doppler US and power Doppler US before and after intravenous administration of contrast agent, and two underwent only color Doppler US. All patients had previously undergone cerebral angiography. RESULTS: Before contrast material was administered, power Doppler US was more sensitive than color Doppler US in the detection of intracranial vessels (P < .05); neither technique depicted the entire circle of Willis in eight of nine patients. Postcontrast power Doppler US depicted more vascular segments than postcontrast color Doppler US (P < .01) or precontrast power Doppler US (P < .01). Use of intravenous contrast material enabled the entire circle of Willis to be evaluated from a single temporal bone acoustic window with both power Doppler US and color Doppler US in all patients. Contrast-enhanced power Doppler US depicted vessels not shown by enhanced color Doppler US. CONCLUSION: Contrast-enhanced power Doppler US depicted more vessels, better demonstrated specific vascular segments, and provided better vascular definition of the intracranial vasculature than contrast-enhanced color Doppler US or unenhanced power Doppler US.     

Atherosclerotic lesions, myocardial damage and lipidograms: a multiarterial study applying an atherometric system and canonical correlation

472 autopsy subjects were examined with the following aims: to study the association pattern of atherosclerotic lesions between different arterial sectors, the impact of serum lipid disorders (total cholesterol, HDL-c, LDL-c, VLDL-c, and triglycerides were analyzed) and the association pattern between the atherosclerotic lesions in different arterial sectors and the degree of heart damage. For morphometric analysis of the vessels (aorta, circle of Willis, coronary, renal, iliac, and femoral arteris) the atherometric system was used. The most relevant results were as follows: the lipid disorders show their greatest impact in the heart, coronary and femoral arteries and abdominal aorta, whereas the strongest correlations between the atherosclerotic lesions in different arterial sectors were found in those with anatomical continuity.