Pathologic alterations in pre- and postsynaptic elements in aged mouse sympathetic ganglia

Summary Dysfunction of the sympathetic autonomic nervous system is an increasingly recognized, although poorly understood, complication of increasing age in experimental animals and man. In this study of young adult (4–6 months old) and aged (12– 24 months old) mice we have examined the ultrastructural appearance of perikarya, dendritic processes, preterminal axons, and synapses in selected sympathetic ganglia as well as the three-dimensional structure of the dendritic arborizations of principal sympathetic neurons using intracellular injections of Lucifer Yellow. Ultrastructural examination demonstrated numerous markedly enlarged presynaptic terminal axons and synapses which distorted the contours of perikarya and dendrites of neurons within the prevertebral celiac/superior mesenteric and paravertebral superior cervical and stellate sympathetic ganglia of aged mice. Dilated preterminal axons had the distinctive ultrastructural appearance of neuroaxonal dystrophy, a pathologic process described in a wide variety of clinical and experimental entities. Dystrophic axons were identical in ultrastructural appearance in young and old animals, differing only in frequency. A distinctive type of ultrastructural alteration, characterized by markedly distended neurites containing numerous vacuoles, was confined to the superior cervical ganglia and also increased in frequency with aging. Although many intraganglionic vacuolated processes disappeared with surgical interruption of the cervical sympathetic trunk, which contains the preganglionic axons innervating the superior cervical ganglia, others persisted. In addition, the presence in some processes of admixed ribosomes, lipofuscin, or continuity with the cell body indicated that numerous neuritic alterations within aged sympathetic ganglia were likely of dendritic origin. Intracellular injections of Lucifer Yellow into principal sympathetic neurons demonstrated that the dendritic arborizations of the celiac/superior mesenteric ganglia neurons of young adult mice were significantly more complex and extensive than those of the superior cervical ganglia. Sympathetic neurons of aged superior cervical ganglia, but not superior mesenteric ganglia, appeared significantly smaller with regard to total dendritic length, extent, and branching when compared to those of young animals. In the aged superior cervical ganglia, short, stunted dendritic processes also exhibited large, focal, often multiple, swellings, a phenomenon infrequently observed in the superior cervical ganglia of young animals. The celiac/ superior mesenteric ganglia of aged or young adult mouse failed to exhibit comparable dendritic swellings. These observations may provide a neuropathological basis for understanding age-related changes in autonomic function observed in animals and man, and provide a model system in which age-related pathogenetic mechanisms resulting in neuroaxonal dystrophy and dendritic alterations can be studied.     

Distribution of preganglionic terminals in the cervical sympathetic ganglia detected by the expression of c-Fos like protein after electric stimulation of the ventral root

To determine the segmental relationship between the upper thoracic spinal cord and cervical sympathetic ganglia, we observed the distribution pattern of postganglionic cells which expressed c-Fos like protein, one of the products of immediate early genes, after electrical stimulation of ventral roots at the T1-T3 spinal segments. We recognized a clear segmental arrangement of postganglionic cells in the stellate ganglion along its rostrocaudal direction corresponding to the segmental arrangement of preganglionic neurons in the spinal cord. That is, postganglionic neurons which expressed c-Fos like protein after stimulation of the T1 ventral root were distributed in the middle region of the stellate ganglion in the rostrocaudal direction. The c-Fos like protein-positive neurons after stimulation of the T2 ventral root were distributed in a more caudal region of the stellate ganglion than after T1 ventral root stimulation. C-Fos like protein-positive neurons after stimulation of the T3 ventral root were mainly situated in a more caudal region of the stellate ganglion than after T2 ventral root stimulation. There was, however, no segmental relationship between the upper thoracic levels of the spinal cord and superior cervical ganglion in the rostrocaudal direction. These results indicate that the segmental innervation of the upper thoracic spinal cord exists in the stellate ganglion, but not in the superior cervical ganglion.     

Electrophysiological and morphological diversity of mouse sympathetic neurons

We have used multiple-labeling immunohistochemistry, intracellular dye-filling, and intracellular microelectrode recordings to characterize the morphological and electrical properties of sympathetic neurons in the superior cervical, thoracic, and celiac ganglia of mice. Neurochemical and morphological characteristics of neurons varied between ganglia. Thoracic sympathetic ganglia contained three main populations of neurons based on differential patterns of expression of immunoreactivity to tyrosine hydroxylase, neuropeptide Y (NPY) and vasoactive intestinal peptide (VIP). In the celiac ganglion, nearly all neurons contained immunoreactivity to both tyrosine hydroxylase and NPY. Both the overall size of the dendritic tree and the number of primary dendrites were greater in neurons from the thoracic and celiac ganglia compared with those from the superior cervical ganglion. The electrophysiological properties of sympathetic neurons depended more on their ganglion of origin rather than their probable targets. All neurons in the superior cervical ganglion had phasic firing properties and large afterhyperpolarizations (AHPs). In addition, 34% of these neurons displayed an afterdepolarization preceding the AHP. Superior cervical ganglion neurons had prominent I(M), I(A), and I(H) currents and a linear current-voltage relationship between -60 and -110 mV. Neurons from the thoracic ganglia had significantly smaller action potentials, AHPs, and apparent cell capacitance compared with superior cervical ganglion neurons, and only 18% showed an afterdepolarization. All neurons in superior cervical ganglia and most neurons in celiac ganglia received at least one strong preganglionic input. Nearly one-half the neurons in the celiac ganglion had tonic firing properties, and another 15% had firing properties intermediate between those of tonic and phasic neurons. Most celiac neurons showed significant inward rectification below -90 mV. They also expressed I(A), but with slower inactivation kinetics than that of superior cervical or thoracic neurons. Both phasic and tonic celiac ganglion neurons received synaptic inputs via the celiac nerves in addition to strong inputs via the splanchnic nerves. Multivariate statistical analysis revealed that the properties of the action potential, the AHP, and the apparent cell capacitance together were sufficient to correctly classify 80% of neurons according to their ganglion of origin. These results indicate that there is considerable heterogeneity in the morphological, neurochemical, and electrical properties of sympathetic neurons in mice. Although the morphological and neurochemical characteristics of the neurons are likely to be related to their peripheral projections, the expression of particular electrophysiological traits seems to be more closely related to the ganglia within which the neurons occur.     

Functional anatomy of the major cardiac nerves in cats

In recognition of the extensive use of the cat as an experimental model of cardiac innervation, the effects of electrical stimulation of stellate ganglia, thoracic vagosympathetic complexes, and individual feline cardiopulmonary nerves on heart rate, blood pressure, and contractility in all four cardiac chambers were analysed and correlated with the anatomy of the thoracic autonomic nervous system. The right and left stellate ganglia in cats are relatively large and globular. Distinct dorsal and ventral ansae subclavia arise from these ganglia, connecting with the relatively small, spindle-shaped middle cervical ganglia situated in the apices of the thoracic cage bilaterally. A cranial pole nerve arises from each of the middle cervical ganglia and courses cranially to unite with the ipsilateral superior cervical ganglia. On each side, the major cardiopulmonary nerves arise from the middle cervical ganglion, the relatively large vagosympathetic trunk, and the stellate ganglion. On the right side these nerves consist of a very small right stellate cardiac nerve, a recurrent cardiac nerve, a group of craniovagal nerves and a group of caudovagal cardiopulmonary nerves. On the left side are the left stellate cardiac, ventrolateral, ventromedial, and innominate cardiopulmonary nerves. All of these nerves contain efferent parasympathetic and/or sympathetic fibers which modify cardiac chronotropism and/or inotropism. Some contain afferent fibers. These results indicate that specific cardiopulmonary nerves exist in cats, which when stimulated, modify the cardiovascular system in specific fashions.     

大白鼠交感神经节内神经肽Y(NPY)样神经元的分布及其功能意义

本文用免疫细胞化学技术研究了大白鼠交感神经的颈上节,星状节,脑部和腹部的交感干节,腹腔节以及肠系膜上、下节内的NPY样免疫反应细胞体的分布。发现NPY样免疫反应细胞体为圆形或椭圆形。NPY样免疫反应产物呈颗粒状分布于细胞质中,多数交感神经节内的免疫反应细胞聚集成群,但椎前神经节内的NPY样免疫反应细胞较分散。本文并讨论了NPY存在于外周去甲肾上腺素能细胞中;NPY可以抑制由于电刺激引起的大白鼠输精管痉挛;局部动脉灌流可引起动脉收缩等问题。本文认为交感神经节中含有的NPY样免疫反应神经元与外周去甲肾上腺素能神经元为同一神经元。NPY对交感神经可能有兴奋或抑制功能。     

The paraventricular nucleus of the hypothalamus sends efferents to the spinal cord of the rat that closely appose sympathetic preganglionic neurones projecting to the stellate ganglion

Using a combination of anterograde and retrograde neuronal tract-tracing techniques, the descending projections from the paraventricular nucleus of the hypothalamus (PVN) to the brain/spinal cord and in particular those axonal projections that appear to be contiguous with sympathetic preganglionic neurones (SPN) projecting to the stellate ganglion have been studied. Descending PVN pathways were located by the anterograde transport of biotinylated dextran amine (BDA), whilst SPN were retrogradely labelled with cholera B toxin subunit conjugated to horseradish peroxidase (CB-HRP). BDA-labelled PVN axons terminated in both hypothalamic and extrahypothalamic (including the midbrain, medulla and spinal cord) brain nuclei, with dense terminal labelling observed particularly in the arcuate hypothalamic nucleus and adjacent median eminence, in the solitary tract, vagal nuclei and in the intermediolateral region of the spinal cord (IML). Varicose descending PVN fibres in the IML were often observed to closely appose both the cell soma and dendrites of retrogradely labelled SPN (projecting to the stellate ganglion) in the spinal cord. In addition, it was shown that PVN descending axons crossing to the contralateral side of the spinal cord were closely associated with retrogradely labelled SPN projecting to the superior cervical ganglion. Such findings suggest that descending pathways from the PVN may exhibit a direct influence on cardiac sympathetic outflow and may also influence the behaviour of the contralateral population of SPN projecting to the superior cervical ganglion. Received: 7 May 1997 / Accepted: 17 October 1997     

神经肽Y在兔颈部交感神经节与脊神经节间通路应用研究

目的　通过电刺激兔颈脊神经节,检测颈交感神经节内的神经肽Y （neuropeptide Y,NPY）含量,研究颈交感神经节与颈脊神经节间的通路联系,探讨颈性眩晕发病机制中的神经解剖学基础。 方法　96只新西兰兔随机分为C2、C3、C4、C5、C6、C7组及相应对照组（每组8只）,麻醉后显露相应的脊神经节,给予波宽0.5 ms、频率30 Hz、5 V电刺激,5秒/次,每1 min重复1次,共5次,30 min后,灌注固定,切取双侧颈上、下交感神经节,切片,免疫反应,染色,观察。 结果　电刺激C2、C3脊神经节后,同侧颈上交感神经节内NPY含量升高（P<0.05）;电刺激C4、C5脊神经节后,同侧颈上交感神经节和颈下交感神经节内NPY含量均有明显变化（P<0.05）;电刺激C6、C7脊神经节后,同侧颈下交感神经节内NPY含量升高（P<0.05）。 结论　颈脊神经节和颈交感神经节间存在神经电生理上的通路联系,且具有节段性、同侧性特点,为颈性眩晕的发病机制及临床分型提供了实验依据和理论基础。     

Development of the NADPH-diaphorase-positive neurons in the sympathetic ganglia

Changes in the distribution of NADPH-diaphorase (NADPH-d) were studied in neurons of the superior cervical ganglion (SCG), stellate ganglion (SG) and celiac ganglia (CG) in newborn, 10-, 20-day-old, 1-month-old, 2-month-old and 6-month-old rats, mice and kittens. NADPH-d-positive neurons were revealed in all sympathetic ganglia in kittens but not in rodents from birth onwards. In kittens, the largest population of NADPH-d-positive cells was found in the SG, the smallest in the SCG (<1%) and we observed only a few cells in the CG. The proportion of NADPH-d-positive cells in the SG increased from 3.1±0.15% in newborn kittens to 9.3±0.63% in 20-day-old animals and decreased further from 8.1±0.75% in 30-day-old kittens to 3.4±0.54% in 2-month-old animals. The content of NADPH-d-positive cells in the CG and SCG did not change during development. There were no differences in cross-sectional area between neurons located in different ganglia of animals from the same age group under study. We conclude that the development of NADPH-d-positive neurons in different sympathetic ganglia has its own time dynamics and is completed by the end of the second month of life.     

Re-innervation of guinea-pig superior cervical ganglion cells by preganglionic fibres arising from different levels of the spinal cord

1. The ability of preganglionic axons to re-establish their normal pattern of synaptic connexions with superior cervical ganglion cells has been studied after section of the cervical sympathetic trunk.

2. In vivo stimulation of the last cervical (C8) and the first seven thoracic ventral roots (T1—T7) 3-4 months after section of the trunk produced end-organ responses similar to those observed in normal animals.

3. The pattern of innervation of individual neurones, determined by intracellular recording of synaptic potentials 4-9 months after cutting the sympathetic trunk, was also similar to that observed in normal neurones. Both normal and re-innervated ganglion cells were contacted by pre-ganglionic axons arising from C8 to T7, and each neurone was usually innervated by a contiguous subset of these segments.

4. Re-innervated neurones, as normal cells, were typically dominated by the innervation from a particular spinal cord segment, with the adjacent segments contributing a synaptic influence that decreased as a function of distance from the dominant segment. This was true whether the amplitude of the post-synaptic potential, or the estimated number of contributing axons, was used as the criterion of segmental dominance.

5. Re-innervated neurones, however, showed some abnormalities. The average number of ventral roots contributing innervation to each neurone was reduced from 4·1 to 3·0, and discontinuities in the sequence of innervating segments were more frequent than in normal neurones. Moreover, fewer preganglionic axons contacted each neurone after regeneration.

6. A further difference between normal and re-innervated neurones during the period covered by these experiments was that axons from the more caudal spinal cord segments were less successful in re-establishing contacts with ganglion cells than those from the rostral segments. The more caudal the position of the preganglionic neurones, the more pronounced was this relative deficiency.

7. Although anomalies of ganglion cell innervation were apparent, the basis for the restoration of normal functional effects appears to be the re-establishment of a pattern of innervation of individual neurones similar to that observed in normal ganglia.

     

Origin of sympathetic and sensory innervation of the temporo-mandibular joint. A retrograde axonal tracing study in the rat.

The cells of origin of sensory and sympathetic innervation of the temporo-mandibular joint were studied by the intraaxonal transport method. Horseradish peroxidase or lectin-conjugated horseradish peroxidase was injected into the temporo-mandibular joint unilaterally in adult rats. Labelled cells were observed ipsilaterally in the superior cervical and stellate sympathetic ganglia, in the sensory trigeminal ganglion and in the second to fifth dorsal root ganglia; none were found contralaterally. The results are discussed in relation to the hypothesis that a nervous mechanism might be involved in the pathogenesis of joint inflammation.     

Sympathetic and sensory innervation of the rat shoulder joint: a WGA-HRP tracing and CGRP immunohistochemical study

The innervation of the shoulder joint of the rat was investigated. Nerve origin was assessed by injection of a neuronal tracer (WGA-HRP) into the shoulder joint cavity and calcitonin gene-related peptide (CGRP), which is known to be present in some sensory neurons, was detected immunohistochemically with an anti-CGRP antibody. In the ipsilateral sympathetic and dorsal root ganglia, 133–312 and 12–55 nerve cell bodies were respectively labeled by injection of the tracer. In the sympathetic ganglia, 83% of all labeled cells were found in the stellate ganglion and 17% in the superior cervical ganglion. In the dorsal root ganglia, 75% of the labeled cells were found in C4 and the neighboring ganglia (C4–C5), while the rest were observed in C6–8 and T3. This suggested that the origin of sensory innervation for the shoulder joint was mainly in the mid-cervical cord. CGRP-immunoreactive fibers were found in the synovial capsule of the shoulder joint. These fibers were fine and resembled type 4 axons as classified by Brodai, i.e., nerve related to pain sensation. These findings indicate that sensory nerves from the mid-cervical cord and sympathetic nerves from the cervical ganglion are distributed to the shoulder joint. It is possible that these nerves are related to symptoms such as pain in patients with frozen shoulder or other diseases.     

Surgical anatomy of the cervical sympathetic trunk

Lack of knowledge of the anatomy of the cervical sympathetic trunk (CST) may complicate surgical procedures on the cervical spine. This study aims to define linear and angular relations of the CST with respect to consistent structures around it, including the number and size of the cervical ganglia, the distances between the CST and the longus colli muscle and the anterior tubercles of the transverse processes of cervical vertebrae. Morphometric parameters of the 24 CSTs of 12 adults were measured on both sides. The CST had superior, middle, and inferior (or cervicothoracic) ganglia in 20.8% of specimens; superior and inferior (or cervicothoracic) ganglia in 45.8%; superior, middle, vertebral, inferior, or cervicothoracic ganglia in 12.5%, and superior, vertebral, inferior or cervicothoracic ganglia in 20.8% of specimens. The superior ganglion was observed in all specimens, the middle ganglion and vertebral ganglion were each observed in 33.3%. There was no difference between the number of superior and vertebral ganglia between the right and left sides. The average distance between the CST and the medial border of the ipsilateral longus colli muscle (LCM) was 17.2 mm at C3 and 12.4 mm at C7. As the CSTs converged caudally, the LCMs diverged. The average distance between the anterior tubercles of transverse processes of the cervical vertebrae and the lateral borders of the ipsilateral CST was 3.4 mm at C4, 3.2 mm at C5, and 3.9 mm at C6. The presence of a vertebral ganglion and variations, such as the localization of the CST within the carotid sheath, are important. The anatomical landmarks described should assist the spinal surgeon to avoid injury of the CST.     

Sympathetic neurons in lower cervical ganglia send axons through the superior cervical ganglion

In addition to the preganglionic axons which innervate the superior cervical ganglia, the cervical sympathetic trunks of the rat have been shown to contain axons of ganglionic neurons. Following the application of horseradish peroxidase to the cut cervical sympathetic trunk just caudal to the superior cervical ganglion, a population of approximately 300 labeled neurons was found in the inferior and middle cervical ganglia. The labeled neurons were localized primarily in the more rostral regions of these ganglia. The axons of most of these neurons entered the superior cervical ganglion, passed through it, and left via the external carotid nerve.The relevance of these observations to physiological studies on the cervical sympathetic nervous system is discussed     

Network of the sympathetic nervous system: Focus on the input and output of the cervical sympathetic ganglion

Unlike the thoracic and lumbar sympathetic nervous systems with paravertebral ganglions in individual spinal segments, the cervical sympathetic nervous system lacks segmental structures corresponding to the spinal segments and only three ganglions, namely the upper and middle cervical ganglions and the stellate ganglion, are present. Single axons have been observed in the ganglions using an anterograde-labeling method to analyze their expansion in order to investigate the relationship between the cervical sympathetic ganglions and the spinal cord in rats. Although segmental structures were not confirmed in the upper cervical ganglion, segmental structures were demonstrated in the stellate ganglion. Next, it was determined that some sympathetic preganglionic neurons, nitric oxide synthetase-positive preganglionic neurons, form dense nerve endings on the upper cervical ganglion neurons that project onto organs closely related to glandular secretion in the head and neck region. Finally, the relationship between the cell body size of upper cervical ganglion neurons and the size of the target was investigated for the three major salivary glands in rats and it was determined that no direct relationship was present.     

逆行标记法研究颈脊神经节至交感神经节的神经反射通路

目的 分析颈交感神经节和颈脊神经节之间的神经纤维联系,探讨颈性眩晕发病的神经反射基础.方法 48只新西兰兔随机分为颈上交感神经节组和颈下交感神经节组及相应对照组,于颈上或颈下交感神经节内分别注入荧光金溶液或生理盐水,分别于存活4、8d后取出双侧颈脊神经节C2～C8,制备冷冻切片并进行荧光显微镜观察分析.结果 颈上交感神...     

The origins of the afferent fibers to the lingual muscles of the dog,a retrograde labeling study with horseradish peroxidase

The origin of the afferent fibers to the lingual muscles of the dog was investigated by means of retrograde transport of horseradish peroxidase (HRP) from injection sites in the tongue and the extrinsic lingual muscles. Intralingual injections were not satisfactory because the enzyme diffused beyond the intrinsic lingual muscles to include virtually all tissues within the tongue. Thus, the resultant retrograde labeling of cell bodies of the trigeminal, geniculate, glossopharyngeal, vagal, and first cervical (C₁) spinal ganglia represented a composite of lingual sensory innervation. In order to confine HRP uptake to intramuscular nerve endings, injections were limited to surgically isolated extrinsic lingual muscles, i.e., the genioglossus, hyoglossus, and styloglossus. After these intramuscular injections, labeled neurons appeared ipsilaterally in the C₁ spinal ganglion, the proximal vagal (jugular) ganglion, and trigeminal ganglion. Earlier suggestions that the lingual proprioceptive neurons of the dog reside in the distal vagal (nodose) ganglion and hypoglossal ganglia were not confirmed. The mesencephalic nucleus of the trigeminal nerve failed to label after enzyme injections into the tongue or the extrinsic lingual muscles. The retrograde labeling of cell bodies in the C₁ spinal ganglion was abolished when HRP injections into the extrinsic lingual muscles were preceded by surgical interruption of the ansa cervicalis or distal section of the hypoglossal nerve. Retrograde labeling of neurons in the proximal vagal ganglion persisted after hypoglossal nerve transections.     

Anatomical evidence of non-parasympathetic cardiac nitrergic nerve fibres in rat

Neuronal nitric oxide synthase (nNOS)-derived nitric oxide (NO) plays a major role in the neural control of circulation and in many cardiovascular diseases. However, the exact mechanism of how NO regulates these processes is still not fully understood. This study was designed to determine the possible sources of nitrergic nerve fibres supplying the heart attempting to imply their role in the cardiac neural control. Sections of medulla oblongata, vagal nerve, its rootlets and nodose ganglia, vagal cardiac branches, Th₁-Th₅ spinal cord segments, dorsal root ganglia of C₈-Th₅ spinal nerves, and stellate ganglia from 28 Wistar rats were examined applying double immunohistochemical staining for nNOS combined with choline acetyltransferase (ChAT), peripherin, substance P, calcitonin gene-related peptide, tyrosine hydroxylase or myelin basic protein. Our findings show that the most abundant population of purely nNOS-immunoreactive (IR) neuronal somata (NS) was observed in the nodose ganglia (37.4 ± 1.3%). A high number of nitrergic NFs spread along the vagal nerve and entered its cardiac branches. All nitrergic neuronal somata (NS) in the nucleus ambiguus were simultaneously immunoreactive (IR) to ChAT and composed only a small subset of neurons (6%). In the dorsal nucleus of vagal nerve, biphenotypic nNOS-IR/ChAT-IR neurons composed 7.0 ± 1.0%, while small purely nNOS-IR neurons were scarce. Nitrergic NS were plentifully distributed within the nuclei of solitary tract. In the examined dorsal root and stellate ganglia, a few nitrergic NS were sporadically present. The majority of sympathetic NS in the intermediolateral nucleus were simultaneously immunoreactive for nNOS and ChAT. In conclusion, an abundant population of nitrergic NS in the nodose ganglion implies that neuronal NO is involved in afferent cardiac innervation. Nevertheless, nNOS-IR neurons identified within vagal nuclei may play a role in the transmission of preganglionic parasympathetic nerve impulses.     

Enkephalin-containing sympathetic preganglionic neurons projecting to the inferior mesenteric ganglion: Evidence from combined retrograde tracing and immunohistochemistry

The origin of fibers containing enkephalin immunoreactivity in the inferior mesenteric ganglion of the guinea-pig was studied by combining retrograde axonal tracing and indirect immunofluorescence techniques. Fast Blue was applied into the inferior mesenteric ganglion. Three days later colchicine was administered into the subarachnoid space in order to increase the peptide content of the spinal cord cell bodies. The drug was injected through a catheter which was inserted into the cisterna magna and moved to the appropriate spinal cord levels. After the colchicine injection the animals were perfused with formalin and the L₂-L₃ spinal cord segments were dissected. Cryostat sections of the spinal cord were analyzed in a fluorescence microscope and subsequently processed for indirect immunohistochemistry using antiserum against enkephalin. Several sympathetic pregnanglionic neurons containing both Fast Blue and enkephalin-like immunoreactivity were seen mainly in the intermediolateral cell column of the cord.The observations strongly support the view that at least some of the enkephalin-containing fibers in the inferior mesenteric ganglion originate in the sympathetic preganglionic nuclei of the spinal cord. These findings are discussed in view of recent physiological studies which have shown that enkephalin may have a presynaptic inhibitory action on preganglionic neurons as well as on substance P containing primary afferent neurons in the inferior mesenteric ganglion.     

Calcitonin gene-related peptide (CGRP)-immunoreactive neurons in the human cervico-thoracic paravertebral ganglia

The occurrence of CGRP-immunoreactive neurons in human paravertebral sympathetic ganglia was investigated and CGRP-immunoreactive perikarya correlated with the distribution of structures which were immunoreactive to other peptides and tyrosine hydroxylase, the key enzyme of catecholamine-synthesis. CGRP-immunoreactive neurons were present in all investigated ganglia (superior cervical ganglion, stellate ganglion, thoracic ganglia IV and VII). Most of the CGRP-immunolabelled cell bodies contained also vasoactive intestinal polypeptide-as well as somatostatin-immunoreactivity. Approximately 40 per cent of the CGRP-immunoreactive neurons were weakly tyrosine hydroxylase-immunolabelled. CGRP-immunoreactive cell bodies appear to be neither identical with the large population of neuropeptide Y-labelled perikarya nor with the large group of cell bodies which were surrounded by leuenkephalin-immunoreactive nerve fibres. Colocalization of CGRP- with vasoactive intestinal polypeptide- and somatostatin-immunoreactivity in postganglionic sympathetic neurons substantiates the suggestion of sympathetic origin of respective peptidergic nerve fibres in sweat glands.