Neurons In Paravertebral Ganglia Research Articles

Efficacy of the Omega-3 Index in predicting NAFLD in overweight and obese adults: A pilot study

ral pathways directed to WAT, BAT and brite/beige fat. Specifically, pseudorabies virus (PRV Bartha) was injected into inguinal WAT (iWAT), interscapular BAT (iBAT) and iWAT transformed to include brite/beige fat cells by exposure of rats to 8 ◦C for 7 days. After injection of PRV with different fluorescent reporters (PRV-red/PRV-green) into the various fat pads, rats were allowed to survive for 5 days to allow transport through the autonomic neuraxis before sacrifice and subsequent histolological analysis to assess the distribution of transynaptically viral-infected neurons. After injection of PRV-red or PRV-green into each of the fat depots in the same animal, distinct labelling patterns were observed in 1st, 2nd, 3rd and 4th order neurons in paravertebral ganglia, spinal cord, brain stem, midbrain and hypothalamus. In addition to these ‘‘private lines’’ of communication to various fat pads, populations of ‘‘command neurons’’ were identified which had collateral axonal projections to different fat pads including those to both brown and white fat. Moreover, the relative percentage of these ‘‘command’’ neurons projecting to iBAT and beiged iWAT increased under conditions of cold exposure. These data including the unique identification of ‘‘command’’ controllers of fat involved with both storage and burning of energy provide a neuroanatomical basis for differentiating the central neural control of white, brown and white fat transferred into brite/beige fat.

Confocal imaging of autonomic preganglionic neurons in the spinal cord of the caecilian Typhlonectes natans (Amphibia: Gymnophiona)

Little is known about the spinal sympathetic organization in the caecilian amphibians. We examined for the first time the location of sympathetic preganglionic neurons (SPNs) in the spinal cord using a panel of specific markers expressed in SPNs. The SPNs of anuran amphibians form two cell columns segregated mainly in the lateral and medial marginal areas of the central gray matter. In the caecilian Typhlonectes natans immunoreactivity for galanin and ChAT is found in most laterally arranged neurons lying in spinal segments 2–7. They are encircled by TH- and nNOS-immunoreactive nerve fibers. These neurons might project specifically to a population of adrenergic sympathetic postganglionic neurons in paravertebral ganglia and/or non-adrenergic sympathetic postganglionic neurons in the celiac ganglia. However the segmental restriction and target specificity of the neurons of the species studied are not known. As mucous and granular glands in the dermis may represent one of the peripheral targets of the adrenergic ganglion cells and reflect the prominent preganglionic cell columns, an immunohistochemical study was done also on these glands. Retrograde-tracing studies are, however, needed to study the segmental localization of the preganglionic neurons and their projections to the postganglionic neurons in sympathetic ganglia.

Expression of TRPV1 in sensory and sympathetic neurons innervating kidney

The transient receptor potential vanilloid 1 (TRPV1) receptor is a ligand-gated cation channel activated by capsaicin, heat, protons and cytosolic lipids. TRPV1 is expressed primarilyin sensory nerves and functions as a molecular integrator for multiple types of sensory input. Recent reports suggest that TRPV1 plays an important role in regulating salt sensitivity during development of hypertension. Our study determined the expression of TRPV1 in the neurons supplying the kidney, which regulates salt balance. We used Fast Blue (FB) to label retrogradely sympathetic and sensory neurons innervating the kidney. In T12 to L4 segments, 4% and 6% or neurons were labeled by FB in dorsal root ganglia (DRG) and paravertebral ganglia (PVG) respectively. Labeled neurons were not found in celiac or nodose ganglia. We used antibodies raised against CGRP and tyrosine hydroxylase (TH) to mark sensory and sympathetic neurons respectively. Immunocytochemical studies showed that TRPV1 was expressed in FB-CGRP labeled DRG neurons and in FB-TH labeled PVG neurons. Whole cell recordings revealed that capsaicin caused in inward current in FB labeled DRG neurons. FB labeled neurons in PVG did not respond to capsaicin. Our data indicate that TRPV1 is expressed in DRG and PVG neurons supplying the kidney. The electrophysiological properties of TRPV1 in PVG differ from that in DRG.

Comparison of extrinsic efferent innervation of guinea pig distal colon and rectum

The extrinsic efferent innervation of the distal colon and rectum of the guinea pig was compared, by using retrograde tracing combined with immunohistochemistry. Application of the carbocyanine tracer DiI to the rectum filled significantly greater numbers of extrinsic neurons than similar injections into the distal colon. Approximately three-fourths of all filled neurons from either location were either sympathetic or parasympathetic; the rest were spinal sensory neurons. Nerve cell bodies in sympathetic prevertebral ganglia labelled from the two regions were similar in number. Both regions were innervated by sympathetic neurons in paravertebral ganglia; however, the rectum received much more input from this source than the colon. The rectum received significantly more input from pelvic ganglia than the colon. The rectum also received direct innervation from two groups of neurons in the spinal cord. Neurons located in the spinal parasympathetic nucleus in segment S2 and S3 were labelled by DiI injected into the rectal wall. Similar numbers of neurons, located in intermediolateral cell column and dorsal commissural nucleus of lumbar segments, also projected directly to rectum, but not colon. The great majority (>80%) of retrogradely labelled nerve cell bodies in sympathetic ganglia were immunoreactive for tyrosine hydroxylase. In pelvic ganglia, retrogradely labelled neurons contained choline acetyltransferase and/or nitric oxide synthase or tyrosine hydroxylase. Although the rectum and colon in this species are continuous and macroscopically indistinguishable, they have significantly different patterns of extrinsic efferent innervation, presumably reflecting their different functions.

Vasoactive intestinal peptide distribution and colocalization with dopamine-β-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-β-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.

Spinal origins of preganglionic B and C neurons that innervate paravertebral sympathetic ganglia nine and ten of the bullfrog.

These experiments were designed to characterize the distribution, morphology, and number of spinal preganglionic neurons that selectively innervate the B- and C-type sympathetic neurons in paravertebral ganglia 9 and 10 of the bullfrog. For this purpose, horseradish peroxidase (HRP) was applied to the anterior end of the sectioned sympathetic chain between ganglia 8 and 9. Subsequent retrograde axonal transport of the HRP labeled ipsilateral spinal neurons whose cell bodies form a column having rostral and caudal boundaries that are, respectively, just caudal to the level of spinal nerve 4 and midway between the entry zones of spinal nerves 7 and 8. In all segments, the labeled preganglionic somata were found in the lateral half of the spinal gray and slightly dorsal to the central canal; a position analogous to that of the intermediolateral cell column in mammals. Most labeled preganglionic neurons were multipolar in shape, and the cell bodies lying between spinal nerves 4 and 5 were, on average, larger than those found between spinal nerves 7 and 8. In transverse sections that were cut near spinal nerve 5, the axons of preganglionic neurons could be seen to exit the cord through ventral roots. Counts of labeled preganglionic neurons indicate that an average +/- S.D. of 338 +/- 89 cells innervate ganglia 9 and 10. Selective labeling of preganglionic B neurons, by cutting spinal nerves 7 and 8 central to their rami communicantes at the time of HRP application, revealed an average +/- S.D. of 137 +/- 31 cells that lie exclusively between spinal nerves 4 and 6. By contrast, selective labeling of preganglionic C neurons, by cutting the sympathetic chain rostral to ganglion 7 at the time of HRP application, revealed an average +/- S.D. of 187 +/- 77 cells in an adjacent portion of the preganglionic column that is bounded by spinal nerve 6 and by a point midway between spinal nerves 7 and 8. These results thus demonstrate a clear segmental segregation between the preganglionic B and C neurons that innervate ganglia 9 and 10.

Paravertebral origin of postganglionic sympathetic fibers in the major splanchnic and distal coeliac nerves as demonstrated by horseradish peroxidase (HRP) retrograde transport method

A significant number of sympathetic neurons in the lower thoracic paravertebral ganglia (lateral chain ganglia) were retrogradely labeled when the central cut end of the ipsilateral major splanchnic nerve was exposed to horseradish peroxidase (HRP) in the cat. HRP-labeled perikarya were found in all ganglia of that region of the chain from which the splanchnic nerve has its origin but they are most numerous in the last thoracic paravertebral ganglion, that adjacent to the T13 segment of the cord. The number of HRP-positive cells diminished rapidly in more rostral ganglia. Labeled cell bodies of postganglionic splanchnic neurons in the paravertebral ganglia were fusiform to oval in shape with cell diameters averaging between 25 to 45 μm. These results demonstrate that the splanchnic nerve contains, in addition to visceral afferents and preganglionic sympathetic constituents, many postganglionic fibers with cell bodies in the paravertebral ganglia. These splanchnic postganglionic axons pass through the coeliac ganglion and continue into distal coeliac nerves.