Anatomical and clinical implications of vagal modulation of the spleen

The vagus nerve coordinates most physiologic functions including the cardiovascular and immune systems. This mechanism has significant clinical implications because electrical stimulation of the vagus nerve can control inflammation and organ injury in infectious and inflammatory disorders. The complex mechanisms that mediate vagal modulation of systemic inflammation are mainly regulated via the spleen. More specifically, vagal stimulation prevents organ injury and systemic inflammation by inhibiting the production of cytokines in the spleen. However, the neuronal regulation of the spleen is controversial suggesting that it can be mediated by either monosynaptic innervation of the splenic parenchyma or secondary neurons from the celiac ganglion depending on the experimental conditions. Recent physiologic and anatomic studies suggest that inflammation is regulated by neuro-immune multi-synaptic interactions between the vagus and the splanchnic nerves to modulate the spleen. Here, we review the current knowledge on these interactions, and discuss their experimental and clinical implications in infectious and inflammatory disorders.

Surgical anatomy of the retroperitoneal spaces, Part IV: retroperitoneal nerves

We present surgicoanatomical topographic relations of nerves and plexuses in the retroperitoneal space: 1) six named parietal nerves, branches of the lumbar plexus: iliohypogastric, ilioinguinal, genitofemoral, lateral femoral cutaneous, obturator, femoral. 2) The sacral plexus is formed by the lumbosacral trunk, ventral rami of S1-S3, and part of S4; the remainder of S4 joining the coccygeal plexus. From this plexus originate the superior gluteal nerve, which passes backward through the greater sciatic foramen above the piriformis muscle; the inferior gluteal nerve also courses through the greater sciatic foramen, but below the piriformis; 3) sympathetic trunks: right and left lumbar sympathetic trunks, which comprise four interconnected ganglia, and the pelvic chains; 4) greater, lesser, and least thoracic splanchnic nerves (sympathetic), which pass the diaphragm and join celiac ganglia; 5) four lumbar splanchnic nerves (sympathetic), which arise from lumbar sympathetic ganglia; 6) pelvic splanchnic nerves (nervi erigentes), providing parasympathetic innervation to the descending colon and pelvic splanchna; and 7) autonomic (prevertebral) plexuses, formed by the vagus nerves, splanchnic nerves, and ganglia (celiac, superior mesenteric, aorticorenal). They include sympathetic, parasympathetic, and sensory (mainly pain) fibers. The autonomic plexuses comprise named parts: aortic, superior mesenteric, inferior mesenteric, superior hypogastric, and inferior hypogastric (hypogastric nerves).

[A prospective study on nerve-sparing radical hysterectomy in patients with cervical cancer]

OBJECTIVE

To assess the nerve-sparing radical hysterectomy (NSRH) technique and its impact on postoperative voiding function.

METHODS

Forty-four patients with International Federation of Gynecology and Obstetrics (FIGO) stage I b1-IIa cervical cancer were enrolled and randomized into NSRH group (study group, n = 22) and conventional radical hysterectomy (CRH) group (control group, n = 22). The pelvic autonomic nerve pathway (including hypogastric nerve, pelvic splanchnic nerve, inferior hypogastric plexus and bladder branch) was completely preserved in the NSRH group. Related parameters were compared between the two groups.

RESULTS

The estimated blood loss in NSRH group and CRH group were (550 +/- 241) ml and (475 +/- 284) ml, respectively, with no significant difference (P > 0.05). The mean operation time in NSRH group and CRH group were (329 +/- 43) min and (272 +/- 56) min, respectively, with a significant difference (P < 0.01). More patients in NSRH group had post-void residual urine volume (PVR) < 100 ml than that in CRH group on day 8 after surgery (68% vs. 18%, P < 0.01). The median duration of postoperative catheterization was significantly shorter in NRSH group (8 - 23 days, median 8 days) than that in CRH group (8 - 32 days, median 20 days; P < 0.01). Neither surgery-related injury nor pathologically positive margin was reported in either of the groups.

CONCLUSIONS

NSRH is a feasible and safe technique for preserving bladder function. Larger prospective studies are needed to confirm the efficacy of this technique.

Anatomy of the Thoracic Splanchnic Nerves in Pigs

The anatomical features of the autonomous nerves, including the greater, lesser and least splanchnic nerves, were examined in 4 female and 4 male adult pigs (Sus scrofa). The origin and course of these nerves were examined with regard to sex and the side of the body. The greater splanchnic nerve was present in all of the animals included in the study, whereas the lesser splanchnic nerve was present at a rate of 87.5% on the right side and 75% on the left side of the median plane. On the other hand, the least splanchnic nerve was present on the right side at a rate of 62.5% and on the left side at a rate of 37.5%. The greater, lesser and least splanchnic nerves on the right side of the median plane were determined to originate from a more cranial location. Furthermore, these nerves were observed to be longer and larger on the right side in comparison with the left side. Evaluation of the findings revealed no significant difference between both sides of the median plane with regard to the origin, course and dimensions of these nerves. Similarly, no significant difference was detected between sexes.

The LANN Technique to Reduce Postoperative Functional Morbidity in Laparoscopic Radical Pelvic Surgery

BACKGROUND

We investigated the feasibility and advantages of introducing Laparoscopic Neuro-Navigation (LANN) into the field of laparoscopic gynecologic radical pelvic surgery.

STUDY DESIGN

In a prospective pilot study, 261 consecutive patients underwent laparoscopic radical pelvic surgery for cervical cancer or deep infiltrating endometriosis of the parametria. During the procedure, dissection and electrostimulation, and consequently, sparing of the pelvic parasympathetic nerves by transection of the parametria, were performed. Postoperative bladder dysfunction was documented.

RESULTS

Laparoscopic dissection and electrostimulation of the pelvic splanchnic nerves were feasible in all patients without any complications, and the rate of postoperative bladder dysfunction was considerably reduced, to less than 1% of the patients.

CONCLUSIONS

The parasympathetic nerve-sparing method using the Laparoscopic Neuro-Navigation technique in laparoscopic radical pelvic gynecologic surgery is a feasible and reproducible technique that preserves postoperative bladder function.

Surgical outcome of para-aortic lymph node dissection preserving neural tissue based on anatomical evaluations

The anatomical distribution of the para-aortic lymph nodes was studied to establish an effective operative procedure that preserves neural tissue for patients with advanced gastric cancer. Para-aortic lesions were anatomically examined in 31 cadavers, and histologic preparations of 14 cadavers were used to evaluate the relationship between para-aortic lymph nodes and surrounding neural tissue. Surgical results were analyzed in patients with D3 gastrectomy based on anatomical findings (n = 33). Anatomically, the splanchnic nerves merged into the celiac ganglion, which consisted of either one ganglion (type I) or several ganglia (type II). The average number of lymph nodes were 17.4 in the area superior to the superior mesenteric artery (SMA) and 13.3 in the area inferior to the SMA. According to the number of metastatic lymph nodes (< or = 3, > or = 4), the median survival time was 14.7 and 9.7 months, respectively (P < 0.02). Patients either with or without metastatic lymph nodes behind the neural tissue had a median survival time of 14.7 and 9.7 months, respectively (P < 0.02). We conclude that para-aortic lymph node dissection preserving neural tissue is useful in patients with three or fewer para-aortic metastatic lymph nodes that are in front of the neural tissue.

Anatomical studies of the neurovascular bundle and cavernosal nerves

OBJECTIVE

To accurately define the anatomy of the neurovascular bundle (NVB) in men.

MATERIALS AND METHODS

The NVB was microdissected in detail bilaterally in 12 fixed human male adult cadavers. The anatomy of the NVB and its relationship to surrounding pelvic structures was ascertained in each specimen.

RESULTS

Previous reports of the anatomy of the NVB have not mentioned its levator ani and anterior rectal component. The anatomy of the cavernosal nerves is such that accurate graft anastomosis to proximal and distal cavernosal nerve segments is extremely difficult.

CONCLUSION

The current anatomical description of the cavernosal nerve and NVB is inaccurate.

ANATOMICAL ANALYSIS OF THE NEUROVASCULAR BUNDLE SUPPLYING PENILE CAVERNOUS TISSUE TO ENSURE A RELIABLE NERVE GRAFT AFTER RADICAL PROSTATECTOMY

PURPOSE

Urologists and anatomists have disagreed concerning pelvic neurovascular bundle (NVB) structure. Recently interposition nerve grafting has been performed to improve erectile function after radical prostatectomy. To refine this procedure we reviewed NVB structure from the surgical viewpoint.

MATERIALS AND METHODS

Seven fresh cadavers and serial horizontal sections from 20 formalin fixed cadavers were used for gross dissection and histological examination.

RESULTS

Fresh cadaver dissections demonstrated that the pelvic splanchnic nerve (PSN) joined the NVB at a point distal or inferior to the bladder-prostate (BP) junction. Histologically hypogastric nerve fibers were much more dominant than PSN fibers at the BP junction, and the NVB, covered by the lateral pelvic fascia, became evident at levels more than 20 to 30 mm below the BP junction. PSN components joined the NVB in a spray-like distribution at multiple levels more than 20 mm distal to the BP junction. At these low levels nerves tended to be located outside of the NVB at the dorsolateral margin of the prostate. The cranial end of the mimic interposition nerve graft was directed toward the hypogastric nerve rather than the PSN.

CONCLUSIONS

In contrast to general clinical opinion, the NVB appears to supply few PSN components at the BP junction with caudal PSN branches reaching the dorsolateral prostate more than 20 mm below the BP junction. This anatomy has important implications for a reliable nerve graft.

Laparoscopic identification of pelvic nerves in patients with deep infiltrating endometriosis

BACKGROUND

Nerve sparing is suggested for cancer surgery, but no experience is available for deep endometriosis. The aim of this study was to laparoscopically identify the pelvic nerves in the posterior pelvis.

METHODS

A total of 24 patients operated for deep endometriosis were considered. During surgery and on videotapes of the procedures, we evaluated single- or double-sided resection of the uterosacral ligaments and other structure's visualization of the inferior hypogastric and the splanchnic nerves. The most important objective criteria for resection of the nerves was urinary retention after surgery, which was compared to surgical resection on the videotapes.

RESULTS

Visualization of the inferior hypogastric nerves was possible in 20 of 22 patients (90.1%). Eight of the 24 patients had at least one inferior hypogastric nerve resected (33.3%). In seven patients (29.2%) resection of the uterosacral ligaments was bilateral, and in three of these the nerves were resected. Postoperatively, the median residual urine volume after the first spontaneous voiding was 40 ml (range, 20-400). Seven of eight patients (29.2%) with resection of the nerves had urinary retention and self-catheterization at discharge. The difference in urinary residuum after first voiding between patients undergoing self-catheterization and patients released without the catheter was significant ( p < 0.01). The median time to resume the voiding function in patients with self-catheterization was 18 days (range, 9-45).

CONCLUSIONS

Nerve visualization is possible by means of laparoscopic surgery for deep endometriosis in a high rate of patients. Careful technique is necessary, but the laparoscopic approach may help. Even single-sided radical dissection can induce important urinary retention.

Origins and courses of the nervous branches to the male urethral sphincter

The striated sphincter of the male urethra, the so-called rhabdosphincter, contributes significantly to urethral closure pressure. It is generally agreed that the somatic nerve fibers from the pudendal nerve innervate the rhabdosphincter, and the autonomic nerve fibers innervate the smooth muscle of the urethra. Although it is difficult to clearly identify the rhabdosphincter macroscopically, we minutely investigated the nerve branches to the urethral sphincter muscle region in 10 male pelvic halves. In addition, the origins and courses of the pudendal plexus in 88 male pelvic halves were investigated. To this region were given branches of the pudendal nerve and the pelvic plexus. The branches from the pelvic plexus to the region generally originated from S4 as the lowest branch of the pelvic splanchnic nerve, and ran along the rectal attachment of the levator ani. The caudal root of the pelvic splanchnic nerve formed a common trunk with the nerve to the levator ani (94%). Various connections were sometimes observed between the pudendal nerve and the branches medial to the levator ani. It is suggested that the somatic nerve fibers from the nerve to the levator ani or from the pudendal nerve might also join the nerve branches to the region from the pelvic plexus.

The origin and course of the greater, lesser and least thoracic splanchnic nerves in New Zealand rabbits

In this study, the origin and course of the greater, lesser and least splanchnic nerves was investigated in 12 adult New Zealand rabbits with regard to sex and the side of the body. There were no significant differences between the female and male rabbits. The greater and lesser splanchnic nerves were present in all the cadavers examined. However, the least splanchnic nerve was found on the right side in 50% of the cadavers (nos. 2, 4, 6, 7, 11 and 12), and on the left side in 75% (1, 2, 4, 6, 7, 8, 9, 11 and 12). With regard to the origin and pattern of the greater, lesser and least splanchnic nerves, there were significant differences between the right and left sides of the body even in the same rabbit. No significant difference was observed between sexes.

The inferior hypogastric plexus (pelvic plexus): its importance in neural preservation techniques

The progress in the surgery of male neurological cancers relies on the anatomico-surgical approach to the pelvic neural structures. The objective of our study was to provide a better understanding of the inferior hypogastric plexus (IHP) and its anatomical relationships in order to spare it during radical prostatectomy. Fifteen male formalin-preserved cadavers which had no sub-umbilical scar were used. In five subjects, the superior hypogastric plexus (SHP) and the pre-sacral plexus were displayed then the IHP and its sacral afferents (pelvic splanchnic nerves or erector nerves of Eckhardt) were dissected out. Serial sections of the IHP were then studied in ten subjects. This allowed its identification on certain imaging sections obtained in pelvic tumor pathology and these made up the "reference cuts". The IHP lies within a fibro-fatty plate which is flat, rectangular, sub-peritoneal, sagittal and symmetrical. It arises at the level of the intersection between the vas deferens and the terminal pelvic ureter and follows the postero-lateral aspect and circumvolutions of the seminal vesicle, with which there is a plane of surgical cleavage. The seminal vesicle is, therefore, an essential landmark for this neural structure. The plane of this cleavage may be used in pelvic cancer surgery. The safest technical means of respecting sexual function and the integrity of the IHP is to keep it at a distance. The preservation of a lateral layer of the seminal vesicle is probably a method of limiting these complications as long as this does not conflict with the oncological clearance. An irregular communicating branch was found in one of five cases between the IHP, the sacral plexus and the pudendal nerve. This communicating branch lay immediately behind the intersection between the vas deferens and the ureter in the sacral concavity. It overhangs the IHP in the seminal vesicle. Impotence remains a frequent complication after radical prostatectomy. The methods of neural preservation at the prostatic apex are known but neural preservation should also be carried out posteriorly at the lateral pole of the seminal vesicle. The possibility of posterior neural preservation may be assessed pre-operatively by study of the "reference sections". The cleavage plane between the seminal vesicle and the IHP may be used intra-operatively to spare the IHP. The cavernous nerve in particular emerges at the antero-inferior border of the IHP before running along the postero-lateral aspect of the prostate. It therefore passes in contact with the seminal vesicle and may as a result be injured during radical prostatectomy with vesiculectomy. A proximal communicating branch between the IHP and the pudendal nerve is irregular. Such communicating branches may explain a better recovery of sexual function in curative neurological cancer surgery. The essential relationship of the IHP is with the seminal vesicle. The two are in tight contact and the seminal vesicle has a true plane of surgical cleavage with IHP. The risk of injuries to the posterior erectile mechanisms can be reduced either by using the cleavage plane between the IHP and seminal vesicle or by leaving a layer of the seminal vesicle when the oncological conditions allow. During celio-surgery, the operator must be careful to retract the little bands of the seminal vesicle and divide the fibrous and vascular tracts which tighten during this maneuver. During an abdominal approach, dissection of the seminal vesicle takes place at the bottom of a real pit. The operator must carry out the division leaving a layer of the seminal vesicle in place rather than trying to extract all the seminal vesicle by placing the forceps blindly. This maneuver is naturally dependent on the oncological situation. The anatomical confirmation of a regular or irregular proximal or distal communicating branch between the IHP and the pudendal nerve is probably an explanation for the sometimes uncertain results of new techniques of neural preservation in curative cancer surgery.

Can intestinal innervation be preserved in pancreatoduodenectomy for cancer? Results of an anatomical study

Twenty dissections were carried out, in all of which the splanchnic nerves, celiac plexuses, capital pancreatic plexus and superior mesenteric plexus were identified and traced. The capital pancreatic plexus was formed from two bundles, the first taking its origin from the right celiac plexus, the second from the superior mesenteric plexus. These two bundles joined together just behind the head of the pancreas. Two preganglionic bundles, a ganglion and two postganglionic bundles composed the superior mesenteric plexus. Postganglionic bundles received fibers from both right and left celiac plexuses. In small cancers a thin layer of nervous tissue around the superior mesenteric artery might be spared in order to avoid diarrhea from intestinal denervation. This study has provided anatomical evidence that a part of the mesenteric plexus, which receives fibers from both left and right celiac plexuses, maintains a sufficient intestinal innervation.

Central projections of thoracic splanchnic and somatic nerves and the location of sympathetic preganglionic neurons in Xenopus laevis

The central and peripheral organization of thoracic visceral and somatic nervous elements was studied by applying dextran amines to the proximal cut ends of the thoracic splanchnic and somatic nerves in Xenopus laevis. Many labeled dorsal root ganglion cells of visceral afferents, and all somatic afferents, were located in a single ganglion of one spinal segment, and the two types of cells were distributed topographically within the ganglion. The labeled sympathetic preganglionic neurons were located predominantly in the same area of the thoracic spinal gray as in other frogs and in mammals. The labeled visceral afferents projected to Lissauer's tract and the dorsal funiculus. The visceral fibers of the tract ascended to the level of the subcerebellar area, supplying collateral branches to the lateral one-third of the dorsal horn and to the area of brainstem nuclei, including lateral cervical and descending trigeminal nucleus, and descended to the filum terminale. The visceral fibers of the dorsal funiculus were distributed to the dorsal column nucleus and the solitary tract. A similar longitudinal projection was also seen in the somatic afferents. The dual central pathway of thoracic primary afferents in the anuran spinal cord is a property held in common with mammals, but the widespread rostrocaudal projection through Lissauer's tract may be a characteristic of the anuran central nervous system. In frogs, the direct transmission of primary afferent information to an extremely wide area of the central nervous system may be important for prompt assessment of environmental factors and control of body functions.

Thoracic splanchnic nerves: implications for splanchnic denervation

Splanchnic neurectomy is of value in the management of chronic abdominal pain. It is postulated that the inconsistent results of splanchnicectomies may be due to anatomical variations in the pattern of splanchnic nerves. The advent of minimally invasive and video-assisted surgery has rekindled interest in the frequency of variations of the splanchnic nerves. The aims of this study were to investigate the incidence, origin and pattern of the splanchnic nerves in order to establish a predictable pattern of splanchnic neural anatomy that may be of surgical relevance. Six adult and 14 fetal cadavers were dissected (n = 38). The origin of the splanchnic nerve was bilaterally asymmetrical in all cases. The greater splanchnic nerve (GSN) was always present, whereas the lesser splanchnic nerve (LSN) and least splanchnic nerve (ISN) were inconsistent (LSN, 35 of 38 sides (92%); LSN, 21 of 38 sides (55%). The splanchnic nerves were observed most frequently over the following ranges: GSN, T6-9: 28 of 38 sides (73%); LSN, when present, T10-11: (10 of 35 sides (29%); and ISN, T11-12: 3 of 21 sides (14%). The number of ganglionic roots of the GSN varied between 3 and 10 (widest T4-11; narrowest, T5-7). Intermediate splanchnic ganglia, when present, were observed only on the GSN main trunk with an incidence of 6 of 10 sides (60%) in the adult and 11 of 28 sides (39%) in the fetus. The higher incidence of the origin of GSN above T5 has clinical implications, given the widely discussed technique of undertaking splanchnicectomy from the T5 ganglion distally. This approach overlooks important nerve contributions and thereby may compromise clinical outcome. In the light of these variations, a reappraisal of current surgical techniques used in thoracoscopic splanchnicectomy is warranted.

Nerve-preserving aortoiliac reconstruction surgery: anatomical study and surgical approach

OBJECTIVE

Dysfunctional ejaculation and, to a lesser extent, dysfunctional erection caused by disruption of efferent sympathetic pathways is a common complication after aortoiliac reconstruction surgery. The aim was to give an anatomic motivation for a nerve-preserving approach on the basis of right-sided unilateral disruption of lumbar splanchnic nerves.

METHODS

Anatomic and microscopic analysis of preaortic and para-aortic retroperitoneal regions in human cadavers was performed. Anatomic analysis was conducted of two aortoiliac reconstruction operations performed on human cadavers; one was performed according to a single-blind procedure, the second with a modified procedure.

RESULTS

The lumbar splanchnic nerves supplying the superior hypogastric plexus from the right side were found to be less voluminous than the left-sided ones. The superior hypogastric plexus was found slightly shifted to the left of the midsagittal plane across the abdominal aorta and its bifurcation. Microscopic analysis revealed a thin fascia between the aorta and the subperitoneal tissue compartment. This fascia was used as a plain of dissection to mobilize the preaortic nerve-plexuses without damage from the aortic wall. Analysis of the specimens operated on showed a significant difference in nerve disruption. The standard procedure caused total disruption of the superior hypogastric plexus and extensive disruption of the inferior mesenteric plexus. The modified procedure only caused right-sided unilateral disruption of lumbar splanchnic nerves.

CONCLUSION

The autonomic nerves supplying the bladder neck, the vas deferens, and the prostate are closely related to the abdominal aorta and its bifurcation. Right-sided unilateral disruption of lumbar splanchnic nerves without further damage to nervous structures would ensure at least one functional sympathetic pathway remaining after aortoiliac reconstruction surgery.

Myelinated nerve fiber analysis of the human greater splanchnic nerve

The purpose of the present study is to analyze the human greater splanchnic nerve in relation to aging. We adopted a new staining method which makes it possible to discriminate various structures of the nervous tissue. We examined 25 human greater splanchnic nerves from cadavers for anatomy dissection. We measured the number, area and perimeter of axons. The results reveal that: (1) there is no correlation between age and the number of axons; (2) the mean area and perimeter of axons increase with age, but not the total area and perimeter. We compared these results with those for the lesser splanchnic nerve. These morphological changes in the greater splanchnic nerve may indicate a kind of compensation through axon hypertrophy for hypofunctions in abdominal organ control.

Spinal cord segments controlling the canine vas deferens and differentiation of the primate sympathetic pathways to the vas deferens

This study was undertaken to explore the spinal cord segments controlling the canine and human vas deferens and differentiation of the mammalian sympathetic pathways to the vas deferens. Thoracolumbar white communicating rami (WCR) were electrically stimulated in the dogs. Stimulation of the 1st, 2nd, 3rd, and 4th lumbar WCR elicited an elevation of intraluminal pressure of the vas deferens in 2, 10, 16, and 14 of 20 dogs examined, respectively, whereas stimulation of sympathetic chain (between the 13th thoracic and 1st lumbar ganglia), 13th thoracic WCR, intermesenteric plexus, and 5th lumbar WCR showed no response in any of the 10, 2, 12, and 5 dogs examined, respectively. Anatomical study of the 118 human lumbar splanchnic nerves of 55 cadavers showed that almost all lumbar splanchnic nerves (96%) originated from L2 and/or L3 sympathetic chain ganglia (L1-2 spinal cord levels). Comparative anatomical study of the mammalian sympathetic pathways to the vas deferens showed that the caudal mesenteric plexus is not divided in rats, rabbits, cats, and dogs and is partially divided into two plexuses in monkeys and completely in humans and that separation of the sympathetic component in the pelvic nerve (isolation of the sacral splanchnic nerve) is in progress in the primate. These results indicate that spinal cord segments controlling the vas deferens are L1-4 in the dog and probably L1-2 in humans and that differentiation of the sympathetic nerve pathways is proceeding at both main and compensatory pathways to the vas deferens in the primate.

Distribution of afferent axons in the bladder of rats

The distribution of afferent axons in the bladder of rats was studied by means of immunohistochemistry for calcitonin gene-related peptide (CGRP), in frozen sections and in wholemount preparations of mucosa and muscle coat. Synaptophysin-immunofluorescence was used for the general detection of all intramural axons. The afferent axons were distributed over four distinct targets: at the base of the epithelium, inside the epithelium, on blood vessels (both arteries and veins) and along muscle bundles. In the mucosa, all the afferent axons, except the perivascular ones, lay either inside the epithelium or in a subepithelial plexus very close to the basal surface of the epithelium. The plexus was thickest in the neck of the bladder and in the initial portion of the urethra, and it became progressively less dense in the adjacent regions; it did not extend beyond the equatorial region, and therefore the mucosa of the cranial region of the bladder had no afferent axons. Most of the axons in the subepithelial plexus were terminal axons and included conspicuous varicosities arranged in very long chains; branching points were numerous, usually at right angles and located at the level of a varicosity; some axons split and then rejoined, forming closed axonal loops. The afferent innervation of the musculature was more diffuse, and appeared uniform throughout the bladder. After unilateral surgical denervation (by excision of the pelvic ganglion 5-7 days earlier) areas of complete denervation were observed, but there were large areas where the innervation was only reduced. The results showed that there is a bilateral innervation of many regions of the mucosa and the musculature, including individual muscle bundles. A substantial number of fibres crossed the midline into the contralateral side of the bladder. CGRP-immunofluorescence in mucosal afferent axons is enhanced in the surviving axons 5 days after contralateral denervation, a change which is interpreted as an early sign of regeneration.

Development of differential preganglionic projections to pre- and paravertebral sympathetic ganglia

Sympathetic preganglionic axons project to spatially distinct targets in the periphery. A precise topographic pattern exists within the thoracic preganglionic cell column relative to the direction of axonal projections within the sympathetic chain. In this study, the time course and pattern of axonal outgrowth from different populations of preganglionic neurons in the chicken embryo is examined in detail to clarify the origin of the topography in this system. Projections to prevertebral targets are established by development of the splanchnic nerves by stage 25, well after the earliest somatic motor projections at stage 19 but at least two stages before the reported onset of paravertebral projections. Further, preganglionic axons that project rostrally into the sympathetic chain may do so earlier than those that project caudally in the chain. The separation of preganglionic axons into prevertebral, rostral paravertebral or caudal paravertebral directions occurs at a common site in the ventral mesenchyme, established by the initial ventromedial projection of the splanchnic nerves. Analysis of the axonal trajectories of rostrally and caudally projecting cells reveals that preganglionic axons are not selectively fasciculated before their point of separation at the sympathetic chain. The patterning of the preganglionic cell column is specified before the establishment of functional connections within the chain, indicating that target contact is not a determinant of the segmental pattern. We suggest that the differential outgrowth of preganglionic axons to peripheral targets is determined by the unique identities of underlying subpopulations of preganglionic axons.

Adrenal medullary ganglion neurons project into the splanchnic nerve

Retrograde tract-tracing was used to study the projections of adrenal medullary ganglion neurons. The splanchnic nerve was cut close to the suprarenal ganglia and the retrograde tracer FluoroGold was applied at the site of nerve transection. Groups of adrenal medullary ganglion neurons exhibited FlurorGold- or Fast Blue-induced fluorescence restricted to the perikarya. Using immunohistochemistry most retrogradely labelled ganglion neurons showed immunoreactivity for neuropeptide Y. In addition, after splanchnicotomy most ganglion neurons expressed galanin and galanin message-associated peptide immunoreactivities which could not be observed in control adrenals. Taken together, the present results strongly indicate that adrenal medullary ganglion neurons project back into the splanchnic nerve perhaps representing feedback system modulating the preganglionic innervation of the adrenal gland.

[The threshold of humanity searched from neurosplanchnocranial angular relations in the sagittal plane]

The measurement of occipito-manducator angles, and especially that of alvéolo-hiatical angle, by his lower apeture, is realizable without necessary skull orientation. It is able to systematize with preciseness the hominity step of a skull, when compared to a threshold estimated to 180 degrees.

Distribution of enteric nerve cells projecting to the superior and inferior mesenteric ganglia of the guinea-pig

Retrograde tracing, using Fast Blue dye, was employed to determine the distribution of enteric nerve cells that project to the superior mesenteric and inferior mesenteric ganglia of the guinea-pig. Retrogradely labelled neurons were found in the myenteric but not submucous ganglia. When the superior mesenteric ganglion was injected, labelled neurons were found in low frequencies (less than 5 nerve cell bodies/cm2) in the duodenum, jejunum, ileum, caecum and proximal colon. The distal colon was analysed in five segments of equal length (1-5; oral to anal). Segment 1 had about 4 labelled nerve cells/cm2, whereas segments 2 to 5 displayed an average of about 25 nerve cells/cm2. The rectum contained about 36 labelled neurons/cm2. After injection of the inferior mesenteric ganglia with Fast Blue, no labelled neurons were found in the duodenum, jejunum, ileum or caecum. No labelled cells were observed in the gallbladder. A small number of labelled cells occurred in the proximal colon and in segment 1 of the distal colon. The frequency of labelled cells increased markedly in the more anal regions of the distal colon, and reached a peak in the rectum (138 cells/cm2). Both nerve lesions and immersion of the cut nerve in Fast Blue solution showed that the superior mesenteric nerve carries the axons of neurons located in the middle distal colon to the superior mesenteric ganglion. Almost half of the neurons in the rectum that project to the inferior mesenteric ganglia do so via the hypogastric nerves.(ABSTRACT TRUNCATED AT 250 WORDS)

Regulation of the bladder neck closure by lumbar splanchnic nerves at ejaculation in the dog

To clarify the role of canine thoracolumbar splanchnic nerves for bladder neck closure during ejaculation, these nerves of adult male mongrel dogs were exposed under anesthesia using ketamine hydrochloride and pentobarbital, and electrical stimulation and anatomical dissection studies were performed. Bladder neck closure by the stimulation of each sympathetic nerve was monitored with a 10 Fr silicon catheter equipped with pressure-sensitive rubber balloon placed at the bladder neck. The dissection study revealed that canine thoracolumbar splanchnic nerves consisted of two nerve groups: one branching from the sympathetic trunks at thoracic and L1 ganglia, reaching caudal mesenteric plexus (CMP) through the anterior wall of the aorta, the other branching from the sympathetic trunks at level L2-L5 ganglia, reaching CMP through the posterior side of the bilateral spermatic arteries. The former were designated intermesenteric splanchnic nerves, the latter lumbar splanchnic nerves. No bladder neck closure was observed by electrical stimulation of the distal end of severed intermesenteric splanchnic nerves or of the sympathetic trunks at the lumbopelvic level among 10 dogs examined. At least one lumbar splanchnic nerve generated the closure in all 10 dogs and generally, a few lumbar splanchnic nerves, generated the closure. The results indicate that bladder neck closure during ejaculation is generated by lumbar splanchnic nerves regardless of their branching levels from lumbar sympathetic ganglia, but not by either intermesenteric splanchnic nerves or pelvic sympathetic trunks.

Distribution and possible origins of substance P-containing nerve fibers in the rat liver

The distribution and possible origins of substance P-containing nerve fibers in the rat liver were investigated by immunohistochemistry and nerve transection. Nerve fibers with substance P-like immunoreactivity formed a more complex network than previously known in the walls of portal vein branches. Substance P-immunoreactive fibers were seen not only in and around the walls of the hepatic artery, but also in close association with the hepatic veins and bile ducts. Transection of the greater splanchnic nerves and/or the vagus nerves indicated that substance P-immunoreactive fibers in the walls of the portal and hepatic veins enter the liver via both nerves, and that those associated with the hepatic artery and bile ducts stem from the greater splanchnic nerves. The widespread distribution of hepatic substance P and its complex innervation pattern within the liver suggest that it is involved in a variety of physiological processes in this organ.

Transhiatal bilateral splanchnicotomy for pain control in pancreatic cancer: basic anatomy, surgical technique, and immediate results in fifty-one cases

The greater splanchnic nerves are largely responsible for innervation of the supramesenteric viscera; their section is known to be efficient to relieve pancreatic pain. Transhiatal splanchnicotomy (THS) is easily performed through a midline laparotomy. The nerve trunks are readily identified in the submediastinal space, far from the pancreatic cancer motivating splanchnicotomy, and can be sectioned safely and completely. After carrying out an anatomic study to determine the level of origin and mode of constitution of the greater splanchnic nerve trunk and its relations to the posterior and lower mediastinum, 51 patients underwent THS for intractable pain caused by unresectable pancreatic adenocarcinoma. THS alone was performed in 22 cases. THS was performed in association with biliary tract diversion or gastroenteroanastomosis in the other cases. All tumors were considered unresectable during surgery, and no patient was operated on with the sole purpose of performing THS. Two deaths (3.9%) were unrelated to THS. Specific morbidity was 6% (one pneumothorax, one chylothorax, and one splenic injury). Immediate postoperative functional results were good in 86.3% of patients treated by THS alone (group 1) and in 80.7% of patients treated by THS and bypass (group II). Functional results decreased to 72.7% in group I and 62.1% in group II, 3 months after surgery. In conclusion, THS appears to be an efficient technique for relief of pancreatic neoplastic pain and need not be combined or confused with medical percutaneous methods of neurolysis.

Pre-spinal convergence between thoracic and visceral nerves of the rat

Dichotomizing sensory axons have been demonstrated in a number of species and are of significance in understanding the possible mechanisms underlying referred pain. The present study reviews work employing fluorescent dyes as tracers to demonstrate afferent dichotomization in the peripheral nervous system. Dichotomization between the intercostal and splanchnic nerves of the rat was demonstrated by means of intraneural transport of Diamidino yellow or Fast blue. Frequency of pre-spinal somato-visceral convergence averaged 2% (range 0.1-21%). Average frequency of convergence was 8.3% (range 2-23.1%) between internal and external intercostal nerves. Control experiments in which axoplasmic transport was inhibited by vinblastine ruled out the possibility of errors from non-axoplasmic transport of the markers. Thoraco-visceral pre-spinal convergence occurs in the rat and is variable in extent.

Ability of each lumbar splanchnic nerve and disability of thoracic ones to generate seminal emission in the dog

Control of seminal emission by canine thoracolumbar splanchnic nerves which constitute the caudal mesenteric plexus (inferior mesenteric and superior hypogastric plexuses in human) was investigated. Electrical stimulation of a splanchnic nerve group which branched from sympathetic trunks at thoracic and L1 ganglia and descended on the ventral wall of the aorta between bilateral spermatic arteries via the intermesenteric plexus did not cause seminal emission in all 13 dogs examined. In contrast, electrical stimulation of the other splanchnic nerve group which branched from lumbar sympathetic trunks at ganglia L1-L5 and descended behind bilateral spermatic arteries induced seminal emission regardless of branching levels or sides. The results indicate that efferent signals via the intermesenteric plexus do not generate seminal emission, while those via each lumbar splanchnic nerve have ability to generate seminal emission in the dog.

The arterial circulation of the left suprarenal gland

The findings in a study of the general circulation of the suprarenal glands in 25 cases, and particularly of the left glands in 50 cases, are presented. The vessels arose from three pedicles: superior, middle and inferior. The inferior pedicle was the most irregular, with a frequent contribution from the gonadal artery to the inferior part of the gland; this artery should not be regarded as merely an accessory vessel. On the left side an inconstant posterior pedicle, separate from the others, was found in 26% of cases. Two forms of gonadal artery supplying the gland (8%) are described, an upper origin type at the renal artery level and an aberrant type.

Skin-visceral divergent projection of cholecystokinin-containing dorsal root ganglion neurons: a tri-labelling study with fluorescent tracers and immunohistochemistry

Skin-visceral divergent projections of cholecystokinin (CCK)-containing dorsal root ganglion neurons were studied by combined technique of fluorescent double-labelling and immunohistochemistry. Fast blue (FB) and nuclear yellow (NY) were injected into the coeliac ganglion and the cutaneous branches of left 9th-11th intercostal nerves, respectively. Three kinds of neurons labelled with fluorescein were observed in T9-11 dorsal root ganglia: FB-labelled neurons with blue-fluorescent cytoplasm; NY-labelled neurons with yellow-fluorescent nucleus and double-labelled neurons with blue cytoplasm and yellow nucleus. The double-labelled neurons were found to account for 2.8% of total labelled neurons. The sections containing neurons labelled with fluorescein were stained by CCK-immunohistochemical procedure. Four kinds of neurons could be identified: NY-neurons with CCK-immunoreactivity (NY+CCK); FB-neurons with CCK-immunoreactivity (FB+CCK); NY+FB neurons with CCK-immunoreactivity (NY+FB+CCK); and neurons only CCK-positive. NY+FB+CCK tri-labelled neurons accounted for approximately 11.5% of NY+FB double-labelled neurons, and for 0.4% of all CCK-positive neurons. The findings clearly indicated that the peripheral processes of some sensory dorsal root ganglion neurons divergently project to both skin and visceral structure and contain CCK.

The vascular and neuronal composition of the lateral ligament of the rectum and the rectosacral fascia

Detailed dissections were performed on 83 pelvic halves from 45 cadavers in order to obtain more accurate data on the composition of the lateral ligament of the rectum and the rectosacral fascia. The middle rectal artery was observed in only 18 out of 81 spcimens (22.2%). The lateral ligament of the rectum was divided into lateral and medial portions, according to the positional relationship to the pelvic plexus. The lateral part consisted of a superoanterior and an inferoposterior subdivision. The main component of the former was the middle rectal artery, while the pelvic splanchnic nerves were contained in the latter. Both compoents can be considered to contribute to the formation of the medial part, although the middle rectal vessels were not always present. The medial part consisted of the rectal branches from the pelvic plexus and their connective tissue. The rectosacral fascia was formed by dense connective tissue between the posterior wall of the rectum and the third and fourth sacral vertebrae. The main components of the fascia were branches of the lateral and median sacral vessels and the sacral splanchnic nerves which arose directly from the sacral sympathetic ganglia.

Classification of the abdominal splanchnic nerves--a preliminary attempt to re-evaluate their nomenclatures

The abdominal splanchnic nerves were observed in 22 cadavers (41 sides). The purpose of the study is to give more accurate definition to each nerve, for there are uncertainties in the nomenclature of these nerves. According to PNA, the abdominal splanchnic nerves are classified into three categories, on the basis of their sizes and their levels, namely Nn. splanchnici major, minor, and imus. Although Mitchell (1935) had already claimed that more attention should be given to the levels of ganglia which gave rise to these nerves, no revision has ever been made. Moreover, there still remains the matter of their destinations, which are more significant in defining them. Therefore, in addition to the conventional criteria for the classification, destinations of the nerves were taken into consideration. In the present study, 36 out of 41 sides were grouped into four types according to the said criteria. 5 exceptional cases were interpreted as results of minor modifications of these four types. Naturally, what is important in describing these nerves is to give clear idea about the actual condition of them. It is expected to give more reasonable nomenclature to these nerves based on the present result.

[Histologic identification of the afferent fibers of the pelvic plexus]

The inferior hypogastric (pelvic) plexus conveys two types of fibres: sympathetic fibres originating in the thoracolumbar sympathetic chain and parasympathetic fibers originating in the sacral anterior rami. By using a histofluorescent stain (glyoxalic acid) and a histochemical stain (thiocholine) in 17 fresh cadavres, we have demonstrated that the sympathetic fibres arise from sacral sympathetic ganglia. These fibres participate in the constitution of the pelvic splanchnic nerves. In this study, we confirm that the inferior roots of the pelvic plexus are not only parasympathetic, but also sympathetic.

An in vitro study of the projections of enteric vasoactive intestinal polypeptide-immunoreactive neurons in the human colon

The anatomical basis of the peptidergic neural control of the human colon is largely unknown. In this study, in vitro retrograde tracing methods have been used on fresh human colon to determine the projection pathways of the enteric nerves and, in particular, those containing vasoactive intestinal polypeptide, one of the most abundant and potent of the gut neuropeptides. Two components of the submucous plexus were identified, the inner one projecting to the lamina propria, and the outer to the circular muscle. The lengths of projections within the submucous plexus were up to 5-14 mm in all directions. Myenteric ganglion cells projected to both longitudinal and circular muscles, for distances of up to only 5 mm. The subpopulation of nerves containing vasoactive intestinal polypeptide arose mainly from the submucous plexus and projected up to 6.5 mm anally, 5 mm orally, and 14 mm within the submucous layer to the mucosa or circular muscle. These findings provide entirely new data on the neuroanatomy of the human colon and may help in the understanding of the neural control of colonic secretion and motility.

The human celiac ganglion and its splanchnic nerves

Forty-six dissections of the celiac ganglion were performed on post-mortem specimens, and the form, location and nervous connections of the ganglion on both sides were studied. The triangular form was the most common observed, the ganglions were found to envelope both the celiac and superior mesenteric arteries, putting them closely together, and forming a celiacomesenteric complex similar to that found in the pig. The splanchnic nerves penetrated the diaphragm through a special triangular opening lateral to the crus, in 70-91%. These findings concerning form and nervous connections are somewhat different from those reported in the literature.

Speculations on the structure/function relationship for vagal and splanchnic afferent endings supplying the gastrointestinal tract

This paper discusses some of the unsettled issues in the study of the afferent innervation of the gastrointestinal (GI) tract. Afferent fibres in the vagus and splanchnic nerves have been studied electrophysiologically and much has been learnt from single fibre recordings. Splanchnic afferent fibres generally terminate in multiple mechanosensitive endings in the mesentery and serosa where they are in a position to monitor tension on the mesenteric attachments. Other mechanoreceptors following a mainly vagal pathway behave as if they are functionally in-series with the muscle elements of the gut wall and signal muscle tension generated passively by distension and actively during contraction. A third group of afferent endings supply the GI mucosa where they are in a position to signal information on the physical and chemical environment of the gut lumen. A complex picture of mucosal sensitivity has emerged with subpopulations of receptors with polymodal sensitivity and quality-specific mechanoreceptors, thermoreceptors and chemoreceptors. Unfortunately, there is little concensus amongst the different research groups because of different experimental paradigms. One group describes specific chemoreceptors, other groups fail to find them. In this minireview I have speculated on the cause of the often conflicting data on GI afferents and the implications this has for the interpretation of visceral receptor mechanisms.

Branches of the thoracic sympathetic trunk in the human fetus

The segmental organization of the thoracic sympathetic trunk and all its ramifications was studied in 6 human fetuses (16-22 weeks) by means of the acetylcholinesterase in toto staining method. Each trunk was divided into 12 sympathetic segments. A segment is defined as that part of the sympathetic trunk which is connected via its rami communicantes with one spinal nerve, without discriminating between grey and white rami. The diameter of the rami communicantes and their direction towards the spinal nerves are variable. The number of peripheral segmental ramifications of the trunk is much larger than assumed previously. Each thoracic sympathetic segment gives off at least 4-5 nerves. Three categories of nerves are discerned: (1) large splanchnic rootlets confined to the greater, lesser and least thoracic splanchnic nerves, (2) medium-sized splanchnic nerves directed towards thoracic viscera, some of which give off branches towards costovertebral joint plexuses and, described for the first time in man, (3) small nerves which ramify extensively and form nerve plexuses in the capsule of the costovertebral joints. The majority of the ramifications is formed by the nerves of the third category. The existence of Kuntz's nerve, connecting the 2nd intercostal nerve and 1st thoracic spinal nerve, is confirmed in four specimens. The nerve plexuses of the costovertebral joints receive a segmentally organized innervation: they receive their input from the neighbouring sympathetic segment and the one cranial to it. It is concluded that the thoracic sympathetic branches in man show a complex, segmentally organized pattern and may have a considerable component of somatosensory nerve fibers. The complex relationships must be taken into account in surgical sympathectomies.

The extrinsic innervation of the rat kidney

The anatomy of the extrinsic renal nerves is described making use of an in toto staining procedure for acetylcholinesterase activity. Nervous connections between the kidney and the celiac plexus, major and minor splanchnic nerves, the lumbar splanchnic nerves and the intermesenteric nerve plexus have been established. Bundles of nerve fibers enter or leave the kidney in the (peri-) hilar region. The occurrence of inter- and intraindividual variability is emphasized. Implications of these findings for the use of the rat as an experimental animal in denervation experiments are discussed.

The central projections of primary afferent neurons of greater splanchnic and intercostal nerves in the rat. A horseradish peroxidase study

The central projections of primary afferent fibers of the greater splanchnic nerve of the rat were investigated using the transganglionic horseradish peroxidase transport technique. In addition, the corresponding spinal ganglion cells and the preganglionic sympathetic neurons were demonstrated. For comparing visceral and somatic afferents, intercostal nerve afferents were labelled by the same technique. Splanchnic afferent dorsal root ganglion cells were found at segments T3 to T13 ipsilaterally, with the greatest density at T8 to T12. Labelled cells represented about 10%-15% of all neurons in the ganglia at maximal projection levels. They were randomly distributed within individual ganglia. The great majority were medium to small sized and round to slightly oval in shape. In the spinal cord, labelled visceral afferent axons were found maximally at T8 to T11, but could be detected in decreasing density up to T1 and down to L1. They were distributed over Lissauer's tract and the dorsal funiculus to a medial and lateral collateral pathway (MCP and LCP, respectively). The MCP, somewhat more prominent than the LCP, was destined primarily to clustered presumptive terminal fields in medial lamina I and outermost lamina IIa. Only a few axons continued further to laminae V and X. Splanchnic afferent axons, most likely derived from the MCP, formed a longitudinal bundle ventral to the central canal. The LCP consisted of more or less well-defined axon bundles emanating from the lateral Lissauer's tract and curving round the lateral edge of the dorsal horn and through the dorsolateral funiculus. Presumptive terminal sites of LCP axons are the lateral laminae I and IIa, the nucleus of the dorsolateral funiculus and the dorsal part of lamina V. A few LCP axons were seen in the vicinity of lateral dendrites of preganglionic sympathetic axons. Visceroafferent terminals were absent from laminae IIb-IV and VII. The possible consequences of the MCP/LCP duality for the central connections of splanchnic afferents are discussed. Some splanchnic afferents ascended to the gracile and cuneate nuclei, and rarely to the spinal trigeminal nucleus. These results fit into the general concept of visceroafferent terminal organization that has emerged during the last few years. Differences to other reports in the detailed arrangement of fibers and terminals are discussed. Somatoafferent cell bodies represented the vast majority of neurons in the respective spinal ganglia. Cell sizes encompassed the whole range from very small to very large without a clear predominance of one particular size class.(ABSTRACT TRUNCATED AT 400 WORDS)

On the anatomical organization of the lumbosacral sympathetic chain and the lumbar splanchnic nerves of the cat--Langley revisited

The anatomy of the sympathetic nervous pathways from the spinal cord to the lumbosacral spinal nerves and to the inferior mesenteric ganglion has been studied systematically in a series of 37 cats. Details of the arrangements of white and grey rami communicantes and the lumbar splanchnic nerves are summarized, and similarities and differences between individuals noted. The description largely follows that of Langley [13] but differs in many ways from those of Harris [6] and Pick [21]. An alternative nomenclature for the segmental ganglia of the paravertebral sympathetic chain is defined, and its rationale presented.

Sympathetic preganglionic efferent and afferent neurons mediated by the greater splanchnic nerve in rabbit

Motion sickness, a multisymptom disorder characterized by abnormal gastrointestinal motility and emesis, can be induced by vestibular effects on the sympathetic portion of the autonomic nervous system. However, the vestibular-autonomic pathways are unknown. As a first step in the analysis, we identified the locus of preganglionic sympathetic neurons (PSNs) and dorsal root afferent ganglionic neurons (DRGs) which supply sympathetic innervation to major portions of the gastrointestinal tract in the rabbit. Retrograde labeling of neurons was obtained by application of horseradish peroxidase (HRP) to the cut end of the greater splanchnic nerve. Labeled PSNs were found, ipsilaterally, within the T1 to T11 spinal cord segments, with the highest density of neurons in T6. Most PSNs were located within the intermediolateral column (IML), but a significant portion also occurred within the lateral funiculus (LF), the intercalated region (IC) and the central autonomic area (CA). The proportion of labeling between the four regions depended on the spinal cord segment. In the midthoracic levels, the distribution of labeled neurons was denser in the IML and LF, and in the caudal thoracic segments, the majority were localized in the IC and CA. Labeled cells in these four areas varied morphologically from large fusiform neurons in the IC to small fusiform neurons in the LF, small stellate neurons in the CA, and medium-size stellate neurons in the IML. The DRGs were labeled in thoracic segments T1 to T12, with the majority between T5 and T11. These labeled DRG somata of the greater splanchnic nerve were smaller in comparison with unlabeled ones.

Primary afferent projections of the major splanchnic nerve to the spinal cord and gracile nucleus of the cat

Splanchnic afferent projections to the spinal cord and gracile nucleus were labeled following the application of HRP to the central cut end of the major splanchnic nerve. Labeled afferent fibers were detected in the ipsilateral dorsal column, in Lissauer's tract (LT), in laminae 1, 5, 7, and 10, and in the dorsal gray commissure at T1-T13 levels of the spinal cord. Afferent projections were not identified in laminae 2-4. Collaterals from LT projected ventrally along the lateral and medial margins of the dorsal horn (called lateral and medial pathways, respectively). Afferents in the lateral pathway formed small bundles, spaced rostrocaudally at intervals of 300-1,000 microns, which passed medially at the base of the dorsal horn into laminae 5, 7, and 10 and to the contralateral spinal cord. Some afferents in the lateral pathway projected to the intermediolateral nucleus where labeled sympathetic preganglionic neurons were located. Afferents in the medial pathway entered the lateral aspect of the dorsal column and projected as a group near the midline rostrally to the medulla. The dorsal column pathway terminated in the ventral gracile nucleus in four or five clusters, each occupying a region ranging in size from 0.01-0.1 mm3 and separated in the rostrocaudal axis by distances of 400-800 microns. These clusters were concentrated in the middle and caudal portions of the nucleus below the obex. A comparison of the present results with those from earlier experiments on the central projections of afferent fibers from the heart, kidney, and pelvic organs demonstrates a consistent pattern of visceral afferent termination in the thoracolumbar and sacral segments of the spinal cord. This is not unexpected, since visceral afferent pathways to different organs perform similar functions, such as the transmission of nociceptive information and the initiation of autonomic reflexes.

Acupuncture points of the typical spinal nerves

Typical spinal nerves have six cutaneous branches which reach to the skin of the body wall in the thorax and abdomen. Each of these six cutaneous branches correlates to an acupuncture point. This communication describes acupuncture points found in the thoracic and abdominal walls using anatomic nomenclature relating to cutaneous branches of the spinal nerves.

Anatomical bases of the transhiatus approach to the greater splanchnic nerve

The level of origin and mode of constitution of the greater splanchnic nerve and its relations in the posterior mediastinum were studied. The aim of this work was to identify the anatomical basis of the transhiatus approach to the right and left greater splanchnic nerves. The azygos venous system was seen to be the main anatomical relation of these nerves. The results of this study should allow the surgeon to perform total bilateral neurotomy.

The distribution of vasoactive intestinal peptide in the rat adrenal cortex and medulla

There is increasing evidence for the role of the autonomic nervous system in the control of adrenal cortical function although the nature of the innervation is as yet unknown. In view of our expanding knowledge of the roles which peptidergic putative transmitters play in the autonomic nervous system, the present study was adrenal gland. Using immunocytochemical methods, VIP was found distributed in fibers in the adrenal cortex and medulla. VIP fibers were found primarily in the capsule and zona glomerulosa of the cortex and in small bundles in the medulla and appeared to innervate the parenchymal cells in both cases. Both colchicine pretreatment and ligation of the splanchnic nerve resulted in an increase in staining of fibers of the cortex and the medulla. Demedullated adrenals (regenerated) exhibited a reduced number of VIP fibers in the zona glomerulosa. It appears that the medullary and at least part of the cortical VIP fibers originate in the medullary VIP cell bodies which are regulated by the splanchnic nerve. The distribution of VIP suggests an important role for this peptide in both adrenal cortical and medullary function and a possible medullary modulation of adrenal cortical function.