Parasympathetic innervation and function of endocrine pancreas requires the glial cell line-derived factor family receptor alpha2 (GFRalpha2)

Vagal parasympathetic input to the islets of Langerhans is a regulator of islet hormone secretion, but factors promoting parasympathetic islet innervation are unknown. Neurturin signaling via glial cell line-derived neurotrophic factor family receptor alpha2 (GFRalpha2) has been demonstrated to be essential for the development of subsets of parasympathetic and enteric neurons. Here, we show that the parasympathetic nerve fibers and glial cells within and around the islets express GFRalpha2 and that islet parasympathetic innervation in GFRalpha2 knockout (KO) mice is reduced profoundly. In wild-type mice, neuroglucopenic stress produced a robust increase in plasma levels of islet hormones. In the GFRalpha2-KO mice, however, pancreatic polypeptide and insulin responses were completely lost and glucagon response was markedly impaired. Islet morphology and sympathetic innervation, as well as basal secretions of the islet hormones, were unaffected. Moreover, a glucose tolerance test failed to reveal differences between the genotypes, indicating that direct glucose-stimulated insulin secretion was not affected by GFRalpha2 deficiency. These results show that GFRalpha2 signaling is needed for development of the parasympathetic islet innervation that is critical for vagally induced hormone secretion. The GFRalpha2-KO mouse represents a useful model to study the role of parasympathetic innervation of the endocrine pancreas in glucose homeostasis.     

Spinal hematoma compressing cauda equina.

Epidural and subdural spinal hematomas are unusual complications of diagnostic lumbar punctures. A renal allograft recipient on anticoagulant therapy underwent lumbar puncture. Urinary retention and evidence of an S2, S3, and S4 neurologic deficit developed subsequently. A myelogram showed a defect of the posterior lumbosacral spinal canal. Urodynamic investigation demonstrated normal sympathetic innervation of the proximal urethra and impaired parasympathetic and pudendal innervation of the detrusor and external urethral sphincter, respectively.     

Alterations in cardiac parasympathetic indices in STZ-induced diabetic rats.

Autonomic neuropathy involving parasympathetic innervation is a complication of diabetes mellitus. Biochemical and morphological indices of the parasympathetic innervation of the heart were investigated in rats after diabetes mellitus was induced with streptozocin (STZ). Choline acetyltransferase (CAT) activity was used as a biochemical marker for parasympathetic innervation. Total CAT activity within the hearts of diabetic rats was unchanged after 1 and 2 wk of diabetes and was significantly reduced after 4, 8, and 12 wk. Morphological changes within the cardiac portion of the parasympathetic innervation were assessed at 8 wk when CAT activity was decreased. In diabetic rats, there was a reduction in both cardiac ganglion cell size and number. In contrast, in insulin-treated STZ-induced diabetic rats, ganglion cells were similar in size and number to those in a control group given 3-O-methylglucose to prevent induction of diabetes mellitus by STZ. Thus, diabetes mellitus is associated with alterations in cardiac parasympathetic innervation in rats, and supplemental insulin protects against these changes. These alterations may contribute to impaired parasympathetic neural control of the heart in diabetes mellitus.     

Synchronized electrical stimulation of the sympathetic and parasympathetic innervation of the bladder: facilitation of the initiation of micturition in the dog

To improve the quality of bladder contractions induced by parasympathetic stimulation and to facilitate the initiation of voiding, we investigated the effect of sympathetic stimulation on the parasympathetic innervation of the bladder in 12 dogs. For the sympathetic system, the lumbar sympathetic trunks were electrically stimulated; for the parasympathetic system, either the pelvic nerve or the ventral root of S2 was stimulated. With voltages at or just above the threshold for achieving a measurable effect on bladder pressure, stimulation of the sympathetic system or the pelvic nerve alone did not lead to voiding, and sacral root stimulation alone elicited voiding in only 7.4 per cent of stimulations. However, when the same stimulus parameters were used for synchronous stimulation, the voiding process was facilitated when sympathetic stimulation was begun five to 10 seconds before parasympathetic stimulation. When the pelvic nerve was used, voiding resulted in 77.7 per cent of stimulations and the bladder was emptied by a mean of 68.7 per cent; with S2 ventral root stimulation, voiding resulted in 83.3 per cent of stimulations and the bladder was emptied by 59.7 per cent. The facilitory effect of sympathetic stimulation was not abolished when the sympathetic trunks were cut centrally to the point of stimulation, but was absent when the hypogastric nerves were transected. We feel that sympathetic stimulation modulates the parasympathetic innervation of the bladder.     

后尿道在生殖泌尿括约机制中的作用

实验观测储尿期以及在拟交感、副交感刺激下犬后尿道「各部压力变化。结果表明，虽然交感、副交感活动在后尿道各段不一，但有一定重叠。精阜平面以上尿道主要参与生殖括约活动，受交感神经调控，精阜平面以下的后尿道对控制尿液具有非常重要的作用，其活动主要受副交感神经和躯体神经支配。     

Clinical pharmacology of the lower urinary tract. New aspects

Neurohistochemical, electron-microscopic, pharmacological and urodynamic investigations have over the past 10 years led to a new concept of the innervation and function of the lower urinary tract. A survey is given of the peripheral innervation, transmitters and receptor functions in the parasympathetic, sympathetic, somatic and sensory innervation of the lower urinary tract. Based on this, rational principles of pharmacological treatment are outlined in the management of the most common dysfunctions of detrusor function and the urethral closure mechanism. Furthermore, a survey is given of dysfunctions of the lower urinary tract which may arise inadvertently during pharmacotherapy of disorders of other organ systems.     

Innervation of the extensor carpi radialis brevis and supinator muscles: Levels of origin and penetration of these muscular branches from the posterior interosseous nerve

Dissections of 30 upper extremities from 15 skeletally mature cadavers were performed to identify the levels of origin and penetration of the innervation of the extensor carpi radialis brevis and supinator muscles. The humeroradial joint was used as a reference point for measurements. The most common pattern of extensor carpi radialis brevis innervation consisted of a single origin from the posterior interosseous nerve at the level of the humeroradial joint branching to penetrate the muscle at a level 30 mm to 60 mm distal to the humeroradial joint. The common innervation pattern of the supinator consisted of multiple origins from the posterior interosseous nerve at a level 0 mm to 30 mm distal to the humeroradial joint with multiple penetrations into the muscle at a level 10 mm to 40 mm distal to the humeroradial joint. Although there is variability in the innervation of the extensor carpi radialis brevis and supinator, our data provide useful patterns concerning the anatomy of these muscular branches from the posterior interosseous nerve. More complete knowledge of this anatomy allows safer approaches for the surgical exposure of the radius and improved diagnosis and localization of radial nerve lesions in the proximal forearm, with improved predictability of recovery of nerve injuries.     

The diagnosis of disorders of the colorectal innervation in children

The problem of congenital and acquired defects of innervation of the distal colon has many unsolved questions for making clinical and histological diagnosis, classification and using methods of treatment. Clinical, radiological and morphological aspects of treatment of 153 patients aged from 2 days to 14 years with disturbances of the colorectal innervation were analyzed. Radiological examination was not sufficient for making the diagnosis. Histological signs of aganglionosis, hypoganglionosis, dysganglionosis, type-A and type-B neuronal intestinal dysplasia in full-thickness biopsy specimens were used to confirm the diagnosis of congenital defects of innervation of the distal colon. The scheme of patho- and morphogenesis and clinico-morphological classification of disturbances of the colorectal innervation were proposed. Hirschsprung's disease was classified as a variant of the disturbance of the colorectal innervation.     

Electrophysiologic tests of bladder innervation as indicators of autonomic neuropathy in diabetes mellitus

Electrophysiologic tests of bladder innervation are considered to be sensitive indicators 2of impaired bladder function in patients with diabetes mellitus (DM). A question arose as to whether these tests could also be considered early indicators of neuropathic visceral involvement. As diabetic neuropathy is a condition involving several systems, it seemed worthwhile to investigate subjects with impaired glucose tolerance (IGT) and patients with DM with several diagnostic tools: sacral evoked responses (SERs), urodynamics, peripheral nerve conduction studies, and cardiovascular autonomic function tests. In the IGT group SERs were found to be within normal limits in all subjects, whereas cardiac parasympathetic function tests were frequently found to be altered, suggesting autonomic involvement even in the presymptomatic period of the disease. In the DM group prolonged latencies of SERs were not constantly associated with urodynamic bladder dysfunctions, suggesting a difference between neurons involved in SERs and neurons actually involved in pelvic parasympathetic innervation of the urinary bladder. Furthermore the alterations of the single diagnostic tests of autonomic neuropathy appeared to be scattered among the patients without any evident relationship between one another or with the duration and the type of the disease. Results do not suggest that electrophysiologic tests of bladder innervation are early indicators of widespread autonomic neuropathic involvement.     

Pseudo-colonic obstruction after lumbar spine surgery: a case report

Acute colonic pseudo-obstruction (Ogilvie's syndrome) is characterised by abdominal distension and massive colonic dilatation without any mechanical cause of obstruction. The pathogenesis remains unknown but likely involves imbalance between sympathetic and parasympathetic colon innervation. This syndrome is well known in orthopaedic surgery, as trauma and orthopaedic surgery have been reported as aetiological factors. Some cases have been reported after cervical discectomy. We report a case of Ogilvie's syndrome after lumbar spine surgery. Medical treatment including parasympathetic agent was unsuccessful and the patient underwent a right colectomy. The pathophysiology and treatment are discussed based on a review of the literature.     

Variations in the Innervation of the Long Head of the Triceps Brachii: A Cadaveric Investigation

Background

Some leading anatomy texts state that all three heads of the triceps brachii are innervated by the radial nerve. The posterior cord of the brachial plexus bifurcates to terminate as the radial and axillary nerves. Studies have noted the presence of axillary innervation to the long head of the triceps brachii muscle, patterns different from the classic exclusive radial nerve supply. An understanding of these variations may assist the clinician in the assessment of shoulder weakness and in preoperative and operative planning of radial and axillary neuropathies.

Questions/Purpose

We aimed to further investigate, in cadaver dissections, the prevalence of axillary nerve contribution to the innervation of the long head of the triceps brachii.

Methods

We performed bilateral brachial plexus dissections on 10 embalmed cadavers combining anterior axillary and posterior subscapular approaches. Two additional unilateral cadaveric brachial plexuses were dissected. The posterior cords were fully dissected from the roots distally. The radial and axillary nerves were followed to their muscle insertion points, the dissections were photographed, and the length of branching segments were measured.

Results

Of the 10 paired cadavers dissected (20 specimens), in only one of the 10 cadavers was the classic innervation pattern of radial nerve observed. The other nine cadavers had varying patterns of radial and axillary nerve innervation, The observed patterns were radial and axillary (dual) on one side with radial alone on the other, dual innervation bilaterally, or axillary with contralateral radial innervation. The two additional unilateral dissected specimens were innervated exclusively by the axillary nerve.

Conclusions

Gross and surgical anatomy sources state that the radial nerve is the sole nerve supply to the long head of the triceps. In our study sample, pure radial innervation of the long head of the triceps brachii was not the predominant nerve pattern. We found four other studies that looked at axillary innervation of the long head of the triceps; of the 62 total cadaver shoulders examined in those studies, 71% were found to have nonclassic innervation patterns. Nonclassic patterns may include purely axillary, dual, or posterior cord innervation to the long head of the triceps, and may account for the majority of innervation to the long head of the triceps. These are similar to our findings.

Clinical relevance

Understanding the innervation of the long head of the triceps and variations in axillary nerve course is critical to the clinical diagnosis of injury, surgical treatment options, and rehabilitation of axillary nerve injuries. With this information, the practitioner may have additional surgical options, clearer rationales for clinical situations, and explanations for patient outcomes.

     

Quantitative immunohistochemical study of the innervation of the guinea-pig lower urinary tract

OBJECTIVE: To study the innervation of the different muscle systems of the guinea-pig lower urinary tract, using immunohistochemical and enzyme histochemical methods. MATERIALS AND METHODS: Serial cryostat sections of both genders (four guinea-pigs each) were quantitatively analysed for cholinergic, adrenergic and peptidergic nerve fibre density using specific antibodies or enzyme histochemical labelling. Smooth muscle cell nuclei and varicosities or sectioned nerves were counted in detrusor, internal vesical sphincter (VS), ventral longitudinal musculature (VLM), and dorsal longitudinal musculature (DLM), and the ratios of nerves/nucleus (for detrusor, VLM and DLM) were evaluated statistically. The striated and the smooth external sphincter were examined qualitatively. RESULTS: Detrusor, VS, VLM and DLM had significantly different innervation patterns. In detrusor muscle parasympathetic nerve fibres dominated, while the VS and the urethral muscles had a major sympathetic nerve supply. Neuropeptide Y-positive nerve fibres were abundant in all of the muscles. CONCLUSIONS: Smooth muscles of the lower urinary tract of the guinea-pig are distinct muscular units with distinct innervation patterns. Although there are no corresponding studies in humans the general innervation seems to be equivalent in human and guinea-pig, qualifying the guinea-pig for comparative urological studies.     

Autonomic innervation of canine urinary bladder. Cholinergic and adrenergic contributions and interaction of sympathetic and parasympathetic nervous systems in bladder function

On the basis of histochemical and pharmacologic studies, the dog urinary bladder is more appropriately divided between its body and base than between its trigone and detrusor muscles. The bladder's base has a rich cholinergic innervation while its body has a modest cholinergic innervation. The smooth muscle cells of the bladder are not individually innervated but do have an abundance of membrane acetylcholinesterase. Cholinergic stimulation produces a contraction throughout the bladder. The adrenergic innervation is also regional. The base is richly innervated, and the body has a scant but definite innervation. Adrenergic stimulation by norepinephrine produces a beta inhibition of the body and an alpha contraction of the base. The functional significance of these direct effects of cholinergic and adrenergic stimulation are discussed in light of recent findings that support an interaction between the parasympathetic and sympathetic nervous systems in bladder function.     

Course of the innervation supply of medial head of triceps muscle and anconeus muscle at the posterior aspect of humerus (anatomical study)

Introduction In elbow surgery; posterior side of joint has been described as the front door for accessing the elbow pathologies. Triceps splitting, triceps reflection, posterolateral Kocher, posteromedial Bryan-Morrey, modified MacAusland transolecranon approaches are the well known posterior surgical approaches. In the English literature, release and transposition of ulnar nerve on the medial side was fully described in posterior approaches. We believe that there was a need to identify the structures at the lateral aspect of the elbow while an iatrogenic injury may inversely effect an excellent radiological result. Therefore, we exposed the detailed innervation supply to the anconeus muscle and medial head of triceps muscle and tried to show possible denervation sites of these two structures during posterior approaches.Materials and methods This study was performed on 14 elbows in formalin-preserved 7 cadavers. We exposed the course of the innervation supply to the medial head of triceps muscle and anconeus muscle and tried to show possible denervation sites of these two structures during posterior approaches. The branching pattern of radial nerve innervating anconeus muscle and its deriving level from radial nerve was identified. Distance from a vertical line which is passing through lateral epicondyle to branching point was measured.Results The mean distance of the branching point of the nerve to medial head of triceps muscle and anconeus was 168.3 mm (range 130.36–185.4). The nerve to anconeus muscle ran along the posterior aspect of the humerus from the horizontal line passing through lateral epicondyle at a distance of 142.20 mm (range 153.72–136.41) medial to olecranon and at a distance of 47.45 mm (range 77.13–30.14) lateral to olecranon.Conclusion Although splitting the fibers of triceps proximaly increases the exposure of the posterior humerus, innervation of the lateral portion of the medial head of triceps muscle and anconeus muscle may be jeoparadized. Therefore, surgeons who have interest in elbow surgery; (1) should revise the course of the nerve to medial head of triceps and anconeus muscle, (2) be aware of possible iatrogenic injury of the extensor muscles of the elbow via transtricipital approaches, (3) try to choose a more conservative posterior surgical approach.     

Successful disc surgery after 17 years of erectile dysfunction caused by a "silent" disc protrusion

A 35-year-old male with normal erectile function up until the age of 18 years subsequently suffered permanent erectile dysfunction for the next 17 years. At the age of 15 years he had fallen from a horse and landed on his buttocks. He also complained of slight voiding dysfunction. Uroflowmetry showed reduced flow, indicating a possible common neurogenic cause of the disturbed bladder function and erectile dysfunction. CT of the lumbar spine showed a large protrusion of the intervertebral disc L5-S1. After operative removal of the protrusion, a normal erection was achieved after 15 days and urine flow improved at 1 and 2 months and became normal after 3 months. Both erectile and bladder function continued to be normal 10 years later. Thus, the effects of long-lasting mechanical compression of parasympathetic nerves need not be irreversible. Uroflowmetry is also a test for neurogenic aetiology of erectile dysfunction, as bladder contractility and erection are both dependent upon parasympathetic innervation from the spinal segments S2-S4.     

Peptidergic innervation within the prostate gland and seminal vesicle

Summary An immunohistochemical study in which antisera against several neuropeptides were used demonstrated the presence of neuropeptide Y(NPY) and vasoactive intestinal polypeptide (VIP) immunoreactivity in nerve fibers in the human prostate gland and seminal vesicle, whereas no immunostaining for substance P and calcitonin gene-related peptide was observed. The peptidergic innervation was found to be generally moderate to low. NPY-and VIP-immunoreactive fibers were localized in the subepithelial connective tissue as well as the smooth muscle layers in both organs, although the peptidergic fiber networks were more prominent in the seminal vesicle. Most NPY-immunoreactive fibers were observed in the musculature of the seminal vesicle.In addition, NPY-and VIP-immunoreactive fibers were demonstrated in the walls of blood vessels. The results of our study suggest that the innervation of the prostate gland and seminal vesicle by various neuroactive peptides may be involved in the autonomic regulation of these organs in adult man, as well as sympathetic and parasympathetic nerve fibers.The work reported in this paper was supported by the Walter-Schulz-Stiftung and the Friedrich-Baur-Stiftung     

The anatomic branch pattern of the axillary nerve

The purpose of this study is to determine the surgical anatomy and innervation pattern of the branches of the axillary nerve and discuss the clinical importance of the presented findings. We dissected 30 shoulders in 15 fixed adult cadavers under a microscope through anterior and posterior approaches. The axillary nerve was examined in 2 segments in relation to the underlying subscapularis muscle. The axillary nerve gave off no branches in the first segment in 85% of cases. When the posterior approach was used, the axillary nerve and its branches were observed to be in a triangular-shaped area. The mean distance from the posterolateral corner of the acromion to the axillary nerve and its branches was 7.8 cm. In all cases, the posterior branch of the axillary nerve gave off its first muscular branch to innervate the teres minor. The joint branch of the axillary nerve was observed to branch out in 3 different patterns. The acromial and clavicular parts of the deltoid muscle were observed to be innervated from the anterior branch of the axillary nerve in all cases. The posterior part of the deltoid muscle was observed to be innervated in 3 different patterns. The posterior part of the deltoid was innervated from the branch or branches coming only from the posterior branch in 70% of cases, from the anterior and posterior branches in 26.7% of cases, and from the anterior branch in 3.3% of cases. The findings of this study are useful for identifying each of the branches of the axillary nerve and have implications for surgeries related with selective innervation.     

Neuroanatomy of the pelvis in an infant with cloacal exstrophy: a detailed microdissection with histology

The internal anatomy of the pelvis in the patient with cloacal exstrophy has not been described in detail previously. We present in detail the pelvic anatomical relationships of a patient with cloacal exstrophy who died 72 days after birth and whose body subsequently was perfused with a formalin-based anatomical fluid. Microdissection of the pelvis with histological confirmation of the identity of structures dissected was performed. The vascular supply to the urinary hemibladders arises from the internal iliac arteries, which pass along the lateral portion of the pelvis and enter each hemibladder. The autonomic innervation to the bladder and corporeal bodies arises from a pelvic plexus that lies on the anterior surface of the sacrum. The innervation to the hemibladders then travels in the midline along the posteroinferior surface of the pelvis before extending laterally to communicate with each hemibladder. Autonomic innervation to the duplicated corporeal bodies arises from the sacral pelvic plexus and travels in the midline to pierce the inferior portion of the pelvic floor posterior and medial to the hemibladders. These nerves then enter the crural region of the corpora. Sensory innervation to the corporeal bodies arises from the sacral trunk and passes posterior to the pelvic floor muscles, traveling just medial to the widely separated ischial spines and then laterally along the corporeal bodies. Illustrations of the anatomy and implications for management of the exstrophy patient are presented.     

The cardiovascular reflex tests in autonomic cardiac neuropathy diagnosis

Ewing's five standard cardiovascular reflex tests were used for the assessment of autonomic function. Changes in heart rate during deep inspiration and expiration, Valsalva manoeuvre or standing up evaluate parasympathetic innervation, whereas blood pressure fluctuations during standing up and handgrip evaluate sympathetic innervation. According to physiological principles we must remind that each test is useful predominantly but not exclusively to reveal the impairment of parasympathetic or sympathetic innervation. A total of 271 patients (247 with diabetes mellitus) were estimated for the diagnosis of autonomic neuropathy. Computed time domain analysis of the heart rate variability reveals 21% of the patients with autonomic neuropathy, but this method doesn't rich the performance of spectral analysis witch is x3 times greater. The deep inspiration and expiration remains the preferable test according to its sensibility, specificity and predictive value. I found that handgrip test has, beside the known limitations (arterial hypertension, heart failure, valvular disease, emphysema, advanced diabetic retinopathy, drugs like digitalis, beta-receptor blockers, antihypertensives, sedatives, etc.) one more linked by the hand muscular force. Orthostatic hypertension has too many false results so the interpretation must be done with much precaution.     

Vesicotropic action of digitalis

Digitalis was investigated for its potential effect on pressure-volume relationships in the bladder of monkeys. This drug reproducibly decreased bladder capacity and increased intravesical pressure. This effect appears to be mediated by an increase in tension of the bladder wall. These changes were prevented by prior treatment with atropine which was given to produce pharmacologic impairment of the parasympathetic innervation to the bladder. Digitalis may represent a potentially useful drug for the treatment of some types of hypotonic, neurogenic bladder or bladders with persistent decompensation following correction of associated distal urinary tract obstruction.