Neurochemical features of the autonomic neurons projecting to the cremaster muscle of the boar.

The cremaster muscle (CM) is a striated muscle showing some unusual features for ordinary striated muscles, in fact it receives, besides somatic innervation, a conspicuous autonomic sympathetic innervation. The autonomic neurons associated with the CM of 4 male intact pigs were typified combining the retrograde nontrans-synaptic fluorescent tracer Fast Blue (FB) and double labeling immunohistochemical methods. We collected the L4 sympathetic trunk ganglion (STG), that our preliminary studies proved to contain the highest number (575.5 ± 152.93; mean ± S.E.M., n = 4) of FB+ sympathetic neurons projecting to CM. About half of the CM projecting neurons of this ganglion were catecholaminergic and showed the colocalization of Tyrosine Hydroxylase (TH) with Neuropeptide Y (NPY), Leu-Enkephaline (LENK), Vasoactive Intestinal Polypeptide (VIP), Calcitonine Gene Related Peptide (CGRP), Substance P (SP), neuronal Nitric Oxyde Sinthase (n-NOS), and Vesicular Acetylcholine Transporter (VAChT). The noncatecholaminergic neurons were immunoreactive for all the other markers tested, even if in small percentages. The conspicuous and heterogeneous contribution of the sympathetic autonomic neurons to the muscle innervation is consistent with the hypothesis of a possible origin of the CM fibers by transdifferentiation of the smooth muscle-like gubernaculum mesenchyma into striated myotubes, suggesting that the cremaster myogenesis is independent from that of the abdominal muscles.

Increased nerve fibers in placental bed myometrium in women with preeclampsia.

Narrowing of the uterine spiral arterioles below the deciduomyometrial junction is 1 of the key pathophysiological changes in women with preeclampsia. The contribution of pelvic autonomic nerves to decidualization and impaired placentation in preeclampsia is not clear. Placental bed biopsies were obtained from 10 women with preeclampsia and 23 nornotensive women at caesarean section. We stained them with anti-S100 and CD34 antibodies to detect the presence of nerve fibers and blood vessels, respectively. We detected S100-immunoactive nerve fibers in the myometrium but not in the decidua in both groups of women. S100-immunoactive nerve fiber density in the placental bed myometrium was significantly increased in women with preeclampsia compared to normotensive women. There was no clear relationship between the densities of nerve fibers and CD34-positive blood vessels in these biopsies. These results suggest increased nerve fibers in the placental bed myometrium may play a role in the pathogenesis of the preeclampsia.

Division of autonomic nerves within the neurovascular bundles distally into corpora cavernosa and corpus spongiosum components: immunohistochemical confirmation with three-dimensional reconstruction.

BACKGROUND: Detailed knowledge of the distribution and distal course of periprostatic nerves is essential to improve functional outcomes (erection and continence) after radical prostatectomy (RP). OBJECTIVE: To describe the location of nerve fibres within neurovascular bundles (NVBs) and around the prostate by three-dimensional (3D) computer-assisted anatomic dissection (CAAD) in human foetuses and adult cadavers. DESIGN, SETTING, AND PARTICIPANTS: Serial transverse sections of the pelvic portion were performed in seven human male foetuses and four male adult cadavers. Sections were treated by histologic coloration and neuronal immunolabelling of S100 protein. 3D pelvic reconstruction was achieved with digitised serial sections and WinSurf software. MEASUREMENTS: We evaluated the distribution of nerve fibres within the NVB qualitatively. The distribution of periprostatic nerves was also evaluated quantitatively in the adult specimens. RESULTS AND LIMITATIONS: Periprostatic nerve fibres were dispersed around the prostate on all sides with a significant percentage of these fibres present in the anterior and anterolateral sectors. At the prostate apex and the urethral levels, the NVBs have two divisions: cavernous nerves (CNs) and corpus spongiosum nerves (CSNs). The CNs were a continuation of the anterior and anterolateral fibres around the apex of the prostate, travelling towards the corpora cavernosa. The CSNs were a continuation of the posterolateral NVBs, and they eventually reached the corpus spongiosum. The limitations of this study were the small number of specimens available and the lack of functional information. CONCLUSIONS: The anterolateral position of CNs at the apex of the prostate and the autonomic innervation towards the corpus spongiosum via CSNs indicate possible ways to minimise the effect of prostate surgery on sexual function. The ideal dissection plane should probably include the preservation of the anterolateral tissues and fascias to avoid CN lesions. Anatomic knowledge gained from CAAD pertains directly to proper surgical technique and subsequent recovery of erectile function after RP.

Rationale of pelvic autonomic nerve preservation in rectal cancer surgery based on immunohistochemical study.

PURPOSE: Previous studies revealed that the incidence of cancer cell involvement along the pelvic autonomic nerves ranged from 4 to 14%. However, patients' profiles and methodologies differed among the studies. This study was conducted to clarify the incidence of cancer cell involvement in and around the pelvic autonomic nerves immunohistochemically. METHODS: Immunohistochemical staining was performed on pelvic autonomic nerve specimens resected from 17 patients with p-Stage I-III lower rectal cancers. Antibodies used were pan-cytokeratin (AE1/AE3) for staining cancer cells, S-100 for autonomic nerves, and D2-40 for lymphatic vessels. Lymphatic permeation around the pelvic autonomic nerves was defined as present when AE1/AE3-positive cells were detected in D2-40-stained lymphatic vessels. The presence of metastasis to the interstitial tissue or contaminants was also recorded. RESULTS: TNM staging was stage I in 1, stage II in 5, and stage III in 11 cases, respectively. No cases had lymphatic permeation or metastasis to the interstitial tissue in and around the pelvic autonomic nerves. Cancer cell contaminants were seen in four cases (23%). In three cases (18%), metastatic nodes were located at the root of the middle rectal artery, very close to the pelvic autonomic nerves. CONCLUSIONS: Cancer cell involvement was not seen in and around the pelvic autonomic nerves, suggesting that complete pelvic autonomic nerve preservation may be feasible, unless nerves are invaded by the tumor. In some cases, however, metastatic nodes were seen very close to the nerves. Meticulous lymph node dissection along the pelvic autonomic nerves is mandatory.

Innervation and neurotransmitter localization in the lung of the Nile bichir Polypterus bichir bichir.

Anatomical and functional studies of the autonomic innervation in the lung of dipnoan fishes and the bichirs are lacking. The present immunohistochemical studies demonstrated the presence of nerve fibers in the muscle layers of the lung of the bichir, Polypterus bichir bichir, and identified the immunoreactive elements of this innervation. Tyrosine hydroxylase, acetylcholinesterase, and peptide immunoreactivity was detected in the intramural nerve fibers. Extensive innervation was present in the submucosa where adenylatecyclase/activating polypeptide 38, substance P, P(2)X(2), and 5-hydroxytryptamine (5-HT)-immunoreactive nerve fibers mainly supplied blood vessels. A collection of monopolar neurons located in the submucosal and the muscular layers of the glottis expressed a variety of various transmitters. These neurons may be homologous to ganglion cells in the branchial and pharyngeal rami of the vagus in fishes. Nerves containing 5-HT and P(2)X(2) receptor immunoreactivity projected to the lung epithelium. Associated with neuroepithelial cells in mucociliated epithelium, were neuronal nitric oxide synthase-immunopositive axons. The physiological function of this innervation is not known. The present study shows that the pattern of autonomic innervation of the bichir lung may by similar in its elements to that in tetrapods.

Metastasis-associated S100A4 (Mts1) protein is expressed in subpopulations of sensory and autonomic neurons and in Schwann cells of the adult rat.

S100A4 (Mts1) is a member of a family of calcium-binding proteins of the EF-hand type, which are widely expressed in the nervous system, where they appear to be involved in the regulation of neuron survival, plasticity, and response to injury or disease. S100A4 has previously been demonstrated in astrocytes of the white matter and rostral migratory stream of the adult rat. After injury, S100A4 is markedly up-regulated in affected central nervous white matter areas as well as in the periventricular area and rostral migratory stream. Here, we show that S100A4 is expressed in a subpopulation of dorsal root, trigeminal, geniculate, and nodose ganglion cells; in a subpopulation of postganglionic sympathetic and parasympathetic neurons; in chromaffin cells of the adrenal medulla; and in satellite and Schwann cells. In dorsal root ganglia, S100A4-positive cells appear to constitute a subpopulation of small ganglion neurons, a few of which coexpressed calcitonin gene-related peptide (CGRP) and Griffonia simplicifolia agglutinin (GSA) isolectin B4 (B4). S100A4 protein appears to be transported from dorsal root ganglia to the spinal cord, where it is deposited in the tract of Lissauer. After peripheral nerve or dorsal root injury, a few S100A4-positive cells coexpress CGRP, GSA, or galanin. Peripheral nerve or dorsal root injury induces a marked up-regulation of S100A4 expression in satellite cells in the ganglion and in Schwann cells at the injury site and in the distal stump. This pattern of distribution partially overlaps that of the previously studied S100B and S100A6 proteins, indicating a possible functional cooperation between these proteins. The presence of S100A4 in sensory neurons, including their processes in the central nervous system, suggests that S100A4 is involved in propagation of sensory impulses in specific fiber types.

Different levels of immunoreactivity for synaptosomal-associated protein of 25 kDa in vasoconstrictor and vasodilator axons of guinea-pigs.

Immunoreactivity (IR) for synaptosomal-associated protein of 25 kDa (SNAP-25) was examined in axons of autonomic vasoconstrictor and vasodilator neurons innervating the lingual and uterine arteries of guinea-pigs. Polyacrylamide gel electrophoresis and immunoblotting of protein extracts demonstrated a SNAP-25-IR band at 25 kDa in both arteries. Quantitative confocal microscopy demonstrated significantly higher levels of SNAP-25-IR in varicosities with IR for vasoactive intestinal peptide (VIP) than in adjacent axons with IR for tyrosine hydroxylase (TH). Levels of SNAP-25-IR in TH-IR axons, relative to adjacent VIP-IR axons, were significantly higher in the lingual artery than the uterine artery. These differences in IR for SNAP-25, a protein considered essential for calcium-dependent exocytosis of neurotransmitters, raise the possibility that mechanisms of transmitter release may vary between different classes of autonomic neurons.

Acrylamide-induced neuropathic changes in rat enteric nerves: similarities with effects of streptozotocin-diabetes.

The effect of acrylamide intoxication (a widely used model for autonomic neuropathy) on the fluorescence intensity and density of catecholamine- and peptide-containing nerve fibres and tissue content of noradrenaline and the peptides vasoactive intestinal polypeptide, calcitonin gene-related peptide, substance P and neuropeptide Y in the enteric nerves of rat ileum was examined. Histochemical and immunohistochemical techniques were used to localize catecholamine- and peptide-containing nerve fibres. The tissue content of noradrenaline was measured using high-performance liquid chromatography, and an enzyme-linked immunosorbent assay technique was used to determine the tissue content of the peptides investigated. Acrylamide intoxication caused a significant decrease in the density of catecholamine-containing nerve fibres and tissue content of noradrenaline in the myenteric plexus of rat ileum. A decrease in tissue content and immunoreactivity of calcitonin gene-related peptide and an increase in vasoactive intestinal polypeptide was seen in the myenteric plexus of ileum from acrylamide-intoxicated rats. In the submucous plexus, the acrylamide treatment caused a decrease in calcitonin gene-related peptide immunoreactivity and an increase in vasoactive intestinal polypeptide and neuropeptide Y immunoreactivity. There was no change in either tissue content or immunoreactivity of substance P in both myenteric and submucous plexuses of the treated rat ileum. These changes have a striking similarity with those found in the enteric nerves of streptozotocin-diabetic rat ileum, suggesting the possible presence of an underlying common mechanism(s) in the development of neuropathic changes in the autonomic nerves of acrylamide-intoxicated and streptozotocin-diabetic rats.