Vasoactive intestinal peptide (VIP)-like immunoreactivity in the human sympathetic ganglia

The diversity of neuronal phenotypes in rodent and human autonomic ganglia

Selective sympathetic and parasympathetic pathways that act on target organs represent the terminal actors in the neurobiology of homeostasis and often become compromised during a range of neurodegenerative and traumatic disorders. Here, we delineate several neurotransmitter and neuromodulator phenotypes found in diverse parasympathetic and sympathetic ganglia in humans and rodent species. The comparative approach reveals evolutionarily conserved and non-conserved phenotypic marker constellations. A developmental analysis examining the acquisition of selected neurotransmitter properties has provided a detailed, but still incomplete, understanding of the origins of a set of noradrenergic and cholinergic sympathetic neuron populations, found in the cervical and trunk region. A corresponding analysis examining cholinergic and nitrergic parasympathetic neurons in the head, and a range of pelvic neuron populations, with noradrenergic, cholinergic, nitrergic, and mixed transmitter phenotypes, remains open. Of particular interest are the molecular mechanisms and nuclear processes that are responsible for the correlated expression of the various genes required to achieve the noradrenergic phenotype, the segregation of cholinergic locus gene expression, and the regulation of genes that are necessary to generate a nitrergic phenotype. Unraveling the neuron population-specific expression of adhesion molecules, which are involved in axonal outgrowth, pathway selection, and synaptic organization, will advance the study of target-selective autonomic pathway generation.

Distribution of postganglionic neurons which contain dopamine β-hydroxylase, tyrosine hydroxylase, neuropeptide Y and vasoactive intestinal polypeptide in the human middle cervical ganglion

The middle cervical ganglion (MCG) has been shown to contain neurotransmitters and related substances in the cat, dog and sheep. However, little is known about their presence or distribution in the human MCG. In this study, immunohistochemistry for catecholamine-synthesizing enzymes and neuropeptides was performed on the MCG in human cadavers. In 4 samples of human cadavers, MCG swellings contained numerous postganglionic neurons. In another sample, a distinct swelling of the MCG could not be detected. However, neuronal cell bodies were present within the sympathetic nerve trunk between the superior cervical and stellate ganglia. The cell size analysis demonstrated that cell bodies of postganglionic neurons measured 94.1-1774.1 μm² (mean ± S.D. = 578.1 ± 127.7 μm²) in the MCG. Postganglionic neurons in the MCG were immunoreactive for dopamine β-hydroxylase (DBH, 92.1%), tyrosine hydroxylase (TH, 59.3%), neuropeptide Y (NPY, 71.9%) and vasoactive intestinal polypeptide (VIP, 19.3%). TH-positive neurons in the human MCG appear to be infrequent compared to the sheep MCG in a previous study. In the superior cervical (SCG) and stellate ganglia (SG), 91.0% and 94.2%, respectively, of postganglionic neurons showed DBH-immunoreactivity. A total of 83.8% and 70.4%of them contained TH-immunoreactivity in the SCG and SG. However, expression of NPY in the SG (78.2%) was more abundant than in the SCG (59.1%). Only 16.4% and 13.8% of postganglionic neurons were immunoreactive for VIP in the SCG and SG, respectively. VIP-immunoreactivity was also expressed by nerve fibers surrounding some postganglionic neurons in the MCG (8.7%), SCG (11.5%) and SG (5.9%). The present study suggests that catecholamine, NPY and VIP are neurotransmitters in the MCG, SCG and SG of the human.

Sensory and autonomic neurons project both to the smooth retractor penis and to the striated bulbospongiosus muscles. Neurochemical features of the sympathetic subset

Aim of the present study was to verify, by means of double retrograde neuronal tracers technique, the hypothesis that a subpopulation of sensory and autonomic neurons send collateral axons to both smooth and striated genital muscles. We also wanted to define the neurochemical content of the eventually retrogradelly double labeled (RDL) neurons in the sympathetic trunk ganglia (STG). We used six intact pigs and we injected the tracer Diamidino Yellow (DY) in the smooth left retractor penis muscle (RPM) and the tracer Fast Blue (FB) in the striated left bulbospongiosus muscle (BSM). Rare (2 ± 0.6) RDL neurons were found in the ipsilateral S2 spinal ganglion (SG), 220 ± 42 in the ipsilateral STGs, from L3 to S3, 19 ± 15 in the contralateral S1-S2 ones and 22 ± 5 in the bilateral caudal mesenteric ganglia (CMG). The RDL neurons of the STG were IR for TH (85 ± 13%), DβH (69 ± 17%), NPY (69 ± 23%), nNOS (60 ± 11%), LENK (54 ± 19%), VIP (53±26%), SOM (40 ± 8%), CGRP (34 ± 12%), SP (31 ± 16%), and VAChT (28 ± 3%). Our research highlights the presence of sensory and sympathetic neurons with qualitatively different neurochemical content sending axons both to the smooth RPM and to the striated BSM of the pig. These RDL neurons are likely to project to the smooth vasal musculature to create the ideal physiological conditions in which these muscles can optimize the erectile function.

Developmental changes in vasoactive intestinal polypeptide immunoreactivity in the human paravertebral ganglia

Vasoactive intestinal polypeptide (VIP) belongs to the glucagon-secretin family of polypeptides and possesses numerous functions. Its existence in the mammalian central and peripheral nervous system has been widely documented. However, there are no reports on the developmental aspects of VIP-like immunoreactivity (VIP-IR) in the human postganglionic sympathetic neurons. In this study the availability and distribution of vasoactive intestinal polypeptide has been localized in human stellate ganglia neurons and nerve fibers from neonates, children and adults using the immunohistochemical method. In neonatal ganglia VIP-immunoreactive postganglionic neurons were revealed in a marked population compared to others age-groups. These nerve cells are both small and large in size and are distributed in small clusters or singly in the area of ganglia sections. In children, VIP-IR in ganglionic neurons decreases. In adult stellate ganglia, VIP-immunoreactive postganglionic neurons rarely occur. In ganglia of an individual human only varicosities of VIP-positive nerve fibers were observed. These results provide the age-dependent reduction of VIP-like immunoreactivity in human stellate ganglia neurons and suggest the different role of this peptide in the function of sympathetic ganglia neurons with age.

Comparison of immunohistochemical localization of [Met5]enkephalin-Arg6-Gly7-Leu8, [Met5]enkephalin, neuropeptide Y and vasoactive intestinal polypeptide in the superior cervical ganglion of the rat

The localization of [Met5]enkephalin-Arg6-Gly7-Leu8 and [Met5]enkephalin immunoreactivities was studied in the rat superior cervical ganglion. The distribution of these enkephalin-containing peptides in the ganglion was correlated to that of neuropeptide Y and vasoactive intestinal polypeptide. Three different populations of peptide-containing postganglionic neurons were demonstrated. (1) A minor population (10-20%) of principal neurons was immunoreactive for [Met5]enkephalin-Arg6-Gly7-Leu8 but not immunoreactive for neuropeptide Y nor vasoactive intestinal polypeptide. (2) The major population (about 50-70%) was immunoreactive for neuropeptide Y but not for [Met5]enkephalin-Arg6-Gly7-Leu8. (3) Few vasoactive intestinal polypeptide-immunoreactive principal neurons (less than 2% of all principal neurons) were observed in the ganglion. All vasoactive intestinal polypeptide-immunoreactive neurons were also immunoreactive for neuropeptide Y but not for [Met5]enkephalin-Arg6-Gly7-Leu8. [Met5]enkephalin-Arg6-Gly7-Leu8- and [Met5]enkephalin-immunoreactive nerve fibers had a similar distribution. These enkephalin immunoreactive nerve fibers were seen to enclose both neuropeptide Y-containing principal neurons and neurons devoid of neuropeptide Y immunoreactivity. Furthermore, there were enkephalin-immunoreactive fiber baskets around vasoactive intestinal polypeptide-immunoreactive neurons and sometimes also around solitary enkephalin-immunoreactive neurons. Previously reported diverse role of enkephalins in the rat superior cervical ganglion is supported by this study.

Immunohistochemical localization of neuropeptides in the porcine thoraco-lumbar paravertebral ganglia

The existence and distribution pattern of neuropeptide Y, Met5-enkephalin-Arg6-Gly7-Leu8, vasoactive intestinal polypeptide, calcitonin gene-related peptide, substance P and bombesin/gastrin releasing peptide in the neuronal elements of the thoracolumbar paravertebral ganglia (T4-L6) were studied immunohistochemically in sexually immature female pigs. Subpopulations of nerve cell bodies containing immunoreactivity to neuropeptide Y, Met5-enkephalin-Arg6-Gly7-Leu8, vasoactive intestinal polypeptide and calcitonin gene-related peptide were described. However, neurons were non-immunoreactive for substance P and bombesin/gastrin releasing peptide. The solitary small intensely fluorescent cells contain calcitonin gene-related peptide-, substance P- and Met5-enkephalin-Arg6-Gly7-Leu8-, whereas the some cells in clusters contained only substance P and only substance P and Met5-enkephalin-Arg6-Gly7-Leu8. Immunoreactivities to all studied peptides occurred in the nerve fibres within investigated ganglia. Additionally the number of nerve fibres containing particular peptides as well as their distribution pattern were found to vary. The results of this study were compared with those of previous investigations in other species.

Distribution of neuropeptides in the porcine stellate ganglion

The localization and distribution of neuropeptides including neuropeptide Y (NPY), [Met5]enkephalin-Arg6-Gly7-Leu8 (MEAGL), vasoactive intestinal polypeptide (VIP), calcitonin gene-related peptide (CGRP), substance P and somatostatin (SOM) were analyzed in the stellate ganglion of the pig by use of the indirect immunofluorescence technique. NPY, MEAGL, SOM, VIP and CGRP immunoreactivities were found to exist in subpopulations of neuronal cell bodies of the stellate ganglion. A population of the small intensely fluorescent (SIF) cells showed MEAGL immunoreactivity. In addition, the presence of NPY-, MEAGL-, CGRP-, SP-, SOM- and VIP-immunoreactive nerve fibers and axonal varicosities were observed in the stellate ganglion. The localization and pattern of distribution of these peptides in the porcine stellate ganglion were compared with studies carried out on stellate ganglia of other mammalian species.

Comparison of immunohistochemical localization of [Met5] enkephalin-Arg6-Gly7-Leu8, vasoactive intestinal polypeptide and tyrosine hydroxylase in the major pelvic ganglion of the rat

The major pelvic ganglion is an autonomic ganglion containing both sympathetic and parasympathetic postganglionic neuronal cell bodies. The existence of the proenkephalin A-derived peptide [Met5]enkephalin-Arg6-Gly7-Leu8 immunoreactivity in the rat major pelvic ganglion has been described quite recently. The aim of this study was to compare the relations of [Met5]enkephalin-Arg6-Gly7-Leu8-containing postganglionic neurons and nerve fibers to noradrenergic (tyrosine hydroxylase-immunoreactive) and non-noradrenergic (putative cholinergic) neurons of the rat major pelvic ganglion. Immunohistochemical double staining and elution-restaining techniques were used to investigate the distribution of [Met5]enkephalin-Arg6-Gly7-Leu8 in correlation with tyrosine hydroxylase and vasoactive intestinal polypeptide. The major pelvic ganglion contained neurons immunoreactive either for tyrosine hydroxylase or vasoactive intestinal polypeptide. Many principal neurons, however, were immunoreactive for tyrosine hydroxylase nor vasoactive intestinal polypeptide. [Met5]Enkephalin-Arg6-Gly7-Leu8-immunoreactive principal neurons formed a minor subpopulation in the ganglion and were not immunoreactive for tyrosine hydroxylase. The majority of [Met5]enkephalin-Arg6-Gly7-Leu8-immunoreactive principal cells were non-immunoreactive for vasoactive intestinal polypeptide, but a few of them also contained vasoactive intestinal polypeptide. In contrast to the large [Met5]enkephalin-Arg6-Gly7-Leu8-immunoreactive principal neurons, which formed a population of non-noradrenergic (putative cholinergic) cells, the small [Met5]enkephalin-Arg6-Gly7-Leu8-immunoreactive cell exhibited intense tyrosine hydroxylase immunofluorescence and represented a subpopulation of small, intensely fluorescent cells. [Met5]Enkephalin-Arg6-Gly7-Leu8-immunoreactive pericellular fiber plexuses were found around tyrosine hydroxylase- and vasoactive intestinal polypeptide-immunoreactive principal neurons and in association with small intensity fluorescent cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Neuropeptides in the human celiac/superior mesenteric ganglionic complex: an immunohistochemical study

The occurrence of vasoactive intestinal polypeptide (VIP), peptide histidine-isoleucine (PHI), calcitonin gene-related peptide (CGRP), substance P (SP), somatostatin (SOM), galanin (GAL) and enkephalins (ENK) is studied in the human celiac/superior mesenteric ganglionic complex of pre- and full-term newborns, and adult subjects by means of immunohistochemistry. The antisera used labelled nerve fibres and terminal-like networks for each examined peptide, as well as VIP- and SOM-positive postganglionic neurons. Differences in the relative amount and density of the structures immunoreactive to the various peptides were observed. Moreover, variations in the amount and type of labelled elements were appreciable for each peptide when specimens from subjects at perinatal and adult ages were compared. Double-labelling immunofluorescence for SP and each other peptide showed that co-localization with SP is very frequent for CGRP, moderate to scarce for GAL and SOM, and rare to absent for PHI, VIP and ENK. VIP-, ENK- and CGRP-immunolabeled perikarya bearing the morphological features of the small intensely fluorescent (SIF) cells occurred in the organ. The presence of a paraganglion in one of the specimens examined allowed the detection of VIP- and ENK-positive cell bodies and VIP-, ENK-, SP- and GAL-like immunoreactive varicose nerve fibres in it. The results obtained provide substantial morphological data in support of the involvement of the examined peptides in the chemical interneuronal signalling in the human celiac/superior mesenteric ganglia.

Localization of neuropeptide Y in human sympathetic ganglia: correlation with met-enkephalin, tyrosine hydroxylase and acetylcholinesterase

The relationships of immunoreactive neuropeptide Y, enkephalin and tyrosine hydroxylase, on the one hand, and acetylcholinesterase histochemical activity, on the other, were studied in human lumbar sympathetic ganglia. Two thirds of the ganglion cells contained immunoreactive neuropeptide Y. Electron microscopically the immunoreaction was localized in the Golgi apparatus and in large dense-cored vesicles in the nerve endings. Most of the neuropeptide-containing neurons and nerve fibres were also reactive for tyrosine hydroxylase. Nerve fibres reactive for neuropeptide Y were found around ganglion cells regardless of their transmitter contents, whereas enkephalin-reactive nerve terminals surrounded only acetylcholinesterase-containing neurons. The results demonstrate that neuropeptide Y is colocalized with noradrenaline in most of the human sympathetic neurons and that the nerve fibres may innervate selectively the noradrenergic and cholinergic subpopulations of ganglion cells depending on the transmitters of the nerves.

Vasoactive intestinal peptide distribution and colocalization with dopamine-beta-hydroxylase in sympathetic chain ganglia of pig

The extent to which vasoactive intestinal peptide (VIP) occurs in postganglionic cells of the sympathetic chain and whether these cells are noradrenergic, cholinergic, or neither is unknown. We have (1) established the extent of VIP-containing cell bodies and fibers in all levels of the sympathetic chain in pig and (2) determined the coexistence of VIP and dopamine-beta-hydroxylase (DBH) using immunofluorescence. Weanling pigs were perfusion fixed. Alternate serial frozen sections of cervical, thoracic and lumbar paravertebral ganglia were processed for immunofluorescence with antisera to VIP or DBH. VIP-immunoreactive cells were most evident in thoracic ganglia with a few occurring in stellate and lumbar ganglia. While the cells were distributed throughout individual thoracic ganglia, intensely stained cells consistently occurred just proximal to exiting fiber bundles and sent long processes into these bundles. VIP-immunoreactive fibers occurred in all ganglia. Fiber density varied at each level. Varicose fibers with VIP staining were found to be especially evident from the caudal cervicothoracic ganglion through upper lumbar ganglia, in many cases forming networks of beaded varicosities around principal ganglion cells. Fibers and cells were associated with both interganglionic connectives and rami. A majority of neurons in all ganglia were DBH-immunoreactive but with varying intensities. VIP- and DBH-immunoreactivity coexisted in the same perikarya in some cells in thoracic ganglia, preferentially in cells moderately DBH-immunoreactive. We conclude that VIP-immunoreactive cells are distributed primarily in the thoracic sympathetic chain ganglia and that fibers containing VIP are found at all ganglia levels. Additionally, some VIP-immunoreactive postganglionic neurons in paravertebral ganglia may be noradrenergic.