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

Sympathetic innervation of the development, maturity, and aging of the gastrointestinal tract

The sympathetic nervous system inhibits gut motility, secretion, and blood flow in the gut microvasculature and can modulate gastrointestinal inflammation. Sympathetic neurons signal via catecholamines, neuropeptides, and gas mediators. In the current review, we summarize the current understanding of the mature sympathetic innervation of the gastrointestinal tract with a focus mainly on the prevertebral sympathetic ganglia as the main output to the gut. We also highlight recent work regarding the developmental processes of sympathetic innervation. The anatomy, neurochemistry, and connections of the sympathetic prevertebral ganglia with different parts of the gut are considered in adult organisms during prenatal and postnatal development and aging. The processes and mechanisms that control the development of sympathetic neurons, including their migratory pathways, neuronal differentiation, and aging, are reviewed.

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.

Composite nerve fibers in the hypogastric and pelvic splanchnic nerves: an immunohistochemical study using elderly cadavers

To determine the proportion of nerve fibers in the hypogastric nerve (HGN) and pelvic splanchnic nerve (PSN), small tissue strips of the HGN and PSN from 12 donated elderly cadavers were examined histologically. Immunohistochemistry for neuronal nitric oxide synthase (NOS), vasoactive intestinal peptide (VIP), and tyrosine hydroxylase (TH) was performed. More than 70% of fibers per bundle in the HGN were positive for TH at the level of the sacral promontory. In addition, NOS- (negative) and/or VIP+ (positive) fibers were observed in small areas of each nerve bundle, although the proportion of each was usually less than 10%. In the PSN near the third sacral nerve root, the proportion of nerve fibers positive for NOS and/or VIP (or TH) was below 30%. In both the HGN and PSN, the number of VIP+ fibers was usually greater than that of NOS+ fibers, with frequent co-localization of NOS and VIP. More fibers in both nerves were positive for TH than for these other markers. In contrast to pelvic plexus branches, there were no differences in the proportions of NOS+ and VIP+ fibers between nerve bundles in each of the tissue strips. Thus, target-dependent sorting of nerve fibers was not apparent in the HGN at the level of the sacral promontory or in the PSN near the third sacral nerve root. The NOS+ and/or VIP+ fibers in the HGN were most likely ascending postganglionic fibers to the colon, while those in the PSN root may be preganglionic fibers from Onuf's nucleus.

Expression of vasoactive intestinal polypeptide and calcitonin gene-related peptide in human stellate ganglia after acute myocardial infarction

Using the method of indirect immunofluorescence the distribution of vasoactive intestinal polypeptide (VIP) and calcitonin gene-related peptide (CGRP) was investigated in autopsy specimens of human stellate ganglia following acute myocardial infarction (AMI). The dramatic increase of both VIP- and CGRP-immunoreactivities in principal ganglionic neurons as well as of calcitonin gene-related peptide in perineuronal nets was revealed. It was concluded that hypoxia and myocardial ischaemia following AMI are the main inducing factors for activation of both vasoactive regulatory neuropeptide synthesis. The upregulation of VIP and CGRP expression in sympathetic ganglionic neurons may provide regulatory and trophic support to the ischaemic heart.

Distribution of vasoactive intestinal polypeptide-, calcitonin gene-related peptide-, somatostatin- and neurofilament-immunoreactivities in sympathetic ganglia of human fetuses and premature neonates

The distribution patterns of vasoactive intestinal polypeptide (VIP), calcitonin gene-related peptide (CGRP), somatostatin (SOM) and neurofilament (NF) immunoreactivities (IR) were studied in the stellate ganglia of human fetuses and neonates at 24-26 weeks gestation. Sizeable populations with some quantitative variations of VIP-, CGRP- and SOM immunoreactive nerve cells were detected in all ganglia studied. In marked contrast, neurofilament expression was down-regulated. The upregulation of VIP, CGRP and SOM expression suggested their inductor effect on growth and differentiation neurons as well as on the development of their neurotransmitter properties. The main neuropeptides-inducing factor of sympathetic ganglia in human prenatal ontogenesis may be considered as a relative hypoxia.

Upregulation of vasoactive intestinal polypeptide (VIP) and calcitonin gene-related peptide (CGRP) expression in stellate ganglia of children with congenital cardiovascular lesions

The distribution patterns of vasoactive intestinal polypeptide (VIP) and calcitonin gene-related peptide (CGRP) immunoreactivities (IR) in stellate ganglia of human neonates and infants with congenital heart and vascular lesions were investigated by the method of indirect immunohistochemistry. The results demonstrated upregulation of VIP and CGRP expression in principal ganglionic neurons independently of the type of lesion. It is suggested that the activation of neuropeptide synthesis in stellate ganglia is a compensatory reaction of ganglionic neurons in response to congenital cardiovascular lesions, in regulation of heart contractility, and as a trophic influence on the ischemic myocardium. Hypoxia is the main inducing factor for the upregulation of VIP and CGRP expression in sympathetic neurons.

Calcitonin gene-related peptide (CGRP) expression in the human neonatal paravertebral ganglia

The distribution of calcitonin gene-related peptide-immunoreactivity (CGRP-IR) in human neonatal paravertebral ganglia was demonstrated by the method of indirect immunohistochemistry. A marked population (up to 21%) of CGRP-IR neurons and varicose nerve fibres was observed. The number of calcionin gene-related peptide-immunoreactive neurons varied from ganglion to ganglion in the sympathetic trunk. In addition to its cotransmitter functions, the existence of CGRP in neonatal ganglionic nerve cells was suggested by its inductive and trophic actions on the growth and differentiation of neurons.