Oxytocinergic innervation to the upper thoracic sympathetic preganglionic neurons in the rat

A combination of retrograde cell body labeling and immunohistochemistry was employed to elucidate how oxytocinergic fibers make contact with sympathetic preganglionic neurons (SPNs) in the rat spinal cord from T1 to T4. SPNs were labeled retrogradely using cholera toxin subunit B (CTb) or horseradish peroxidase-conjugated CTb. Oxytocin-immunoreactive (ir) fibers were found in the intermediate zone, including the sympathetic preganglionic subnuclei. In the central autonomie nucleus and the intercalated nucleus, brown-stained oxytocin-ir varicosities or terminals were frequently observed to stud black-stained dendrites of SPNs. Electron microscopical observations showed that oxytocin-ir terminals form synapses with dendrites or soma of the sympathetic preganglionic neurons. The terminals contained numerous small clear round vesicles and a few large, cored vesicles. These results clearly show that a large proportion of SPNs are innervated by oxytocin-containing fibers. The origin of these fibers is discussed, and it is concluded that they are probably descending fibers from the paraventricular nucleus of the hypothalamus.     

Stereological analysis of collagen and elastic fibers in the normal human dermis: Variability with age,sex, and body region

Normal human dermis has been analyzed using sterological methods to estimate the quantitative modifications of collagen and elastic fibers in relation to age, sex, and body region. Forty-five skin biopsies from the trunk or the limbs of 26 males and 19 females of different age were fixed in glutaraldehyde and osmium tetroxide and embedded in epoxy resin. The relative volumes of collagen and elastic fibers were calculated by the point counting method on 1 μm semithin sections. Photographic sampling was performed on four consecutive dermis layers: the papillary layer and three consecutive layers of reticular dermis. The data were subjected to analysis of variance which showed that all the factors studied exert a significant influence on the relative amounts of collagen and elastic fibers. The fractional volume of collagen fibers is constant throughout all dermis layers analyzed and is always higher in females than in males, except for the second and third decades of life. Collagen fiber density increases with age in both sexes up to 30–40 years, when it starts decreasing. Both the relative volumes and the diameters of elastic fibers increase from papillary to deep reticular dermis. In reticular dermis of both sexes there is an increment of elastic fiber density in the first decade of life, followed by a drop particularly marked in males. After 20 years, the relative volume of elastic fibers displays a decreasing trend in females, whereas it increases in males, attaining the highest values beyond the 40s. © 1994 Wiley-Liss, Inc.     

The emerging role of the sympathetic nervous system in skeletal muscle motor innervation and sarcopenia

Examining neural etiologic factors’role in the decline of neuromuscular function with aging is essential to our understanding of the mechanisms underlying sarcopenia, the age-dependent decline in muscle mass, force and power. Innervation of the skeletal muscle by both motor and sympathetic axons has been established, igniting interest in determining how the sympathetic nervous system (SNS) affect skeletal muscle composition and function throughout the lifetime. Selective expression of the heart and neural crest derivative 2 gene in peripheral SNs increases muscle mass and force regulating skeletal muscle sympathetic and motor innervation; improving acetylcholine receptor stability and NMJ transmission; preventing inflammation and myofibrillar protein degradation; increasing autophagy; and probably enhancing protein synthesis. Elucidating the role of central SNs will help to define the coordinated response of the visceral and neuromuscular system to physiological and pathological challenges across ages.This review discusses the following questions: (1) Does the SNS regulate skeletal muscle motor innervation? (2) Does the SNS regulate presynaptic and postsynaptic neuromuscular junction (NMJ) structure and function? (3) Does sympathetic neuron (SN) regulation of NMJ transmission decline with aging? (4) Does maintenance of SNs attenuate aging sarcopenia? and (5) Do central SN group relays influence sympathetic and motor muscle innervation?     

Branches of the thoracic sympathetic trunk in the human fetus

Summary 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 communicates 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.     

Quantitative analysis of the sympathetic innervation of the rat knee joint

Retrograde tracing with Fluoro-Gold (FG) was used to identify the complete population of knee joint sympathetic postganglionic efferents in the lumbar sympathetic chain of adult female Wistar rats. In 6 rats, the total number and distribution of FG-labelled neurons in the lumbar sympathetic chain was determined. The rat knee joint is supplied by an average of 187±57 sympathetic afferents with the majority at the L3 and L4 levels. Immunohistochemistry using antibodies specific for tyrosine hydroxylase (TH), somatostatin (SS) or vasoactive intestinal polypeptide (VIP) revealed that 33% of knee joint sympathetic afferents contained TH, 42% contained VIP, and none contained somatostatin. Retrograde tracing with FG provided accurate and reproducible labelling of the joint-innervating subpopulation of sympathetic efferent neurons. This model lends itself to the further study of the molecular responses of this neuronal population in the various disorders and conditions affecting joints.     

Origin of sympathetic and sensory innervation of the knee joint

Summary The origin of sympathetic and sensory innervation of the knee joint was investigated by the intra-axonal transport method. After injection of horseradish peroxidase (HRP) or horseradish peroxidase conjugated to wheat germ agglutinin (WGA-HRP) into the knee joint unilaterally in adult rats, labelled neurons were found ipsilaterally both in sympathetic and dorsal root ganglia at the lower thoracic and lumbosacral levels. A maximum of 1500 and 1000 peroxidase-positive cells were observed in the sympathetic and dorsal root ganglia, respectively; in the former they were mainly located at the levels of L2–L4, and in the latter mainly at L3–L5. The functional implications of the above observations are discussed in relation to pain mechanisms in joints and to the earlier hypothesis that a nervous component might be involved in the pathogenesis of chronic joint inflammation.     

The release of sympathetic neurotransmitters is impaired in aged rats after an inflammatory stimulus: a possible link between cytokine production and sympathetic transmission

Aging results in a general decline in the response to external insults, including acute inflammatory challenges. In young animals, the inflammatory response requires activation of the sympathetic system, including neurotransmitters such as ATP, and catecholamines (epinephrine and norepinephrine). To test whether aging affects activation of this axis, and whether this in turn might affect cytokine release, we administered lipopolysaccharide (LPS) i.p. to adult, middle-aged and aged Fisher 344 rats (6-, 15- and 23-month old, respectively) and evaluated the early (0-12 h) serum levels of Neuropeptide-Y (NP-Y), ATP and vanillyl mandelic acid (VMA, as an indirect measurement of catecholamine levels). In addition, we evaluated the association between these factors and serum levels of the cytokines tumor necrosis factor-alpha (TNFα) and interleukin-10 (IL-10). Induction of both ATP and NP-Y was markedly reduced in the serum of aged animals, when compared to their younger counterparts, while induction of VMA was not affected by age. In spite of these changes, serum levels of TNFα and IL-10 were strongly hyper induced and delayed in aged rats. The results suggest that during aging there is a dysregulation in sympathetic neurotransmitter regulatory mechanisms, and this might play a role in the impairment of the inflammatory response.     

支配肺血管的脊髓交感神经中枢定位

在大鼠毁髓模型上,对由脊髓C_7～T_(10)节段发出的交感节前纤维逐节进行电刺激时,发现肺循环阻力(PVR)均有不同程度的升高,但在刺激脊髓C_7～T_4节段时PVR升高最为显著(对照值的28%),明显高于其余各节段电刺激后PVR增加的水平。刺激的脊髓节段愈高,△PVR/△SVR比值也愈大。体循环阻力(SVR)的升高则以低位脊髓节段的电刺激时更明显。提示在大鼠脊髓C_7～T_4节段存在支配肺血管运动的交感神经中枢。     

Influence of impulse pattern on noradrenaline release from sympathetic nerves in cerebral and some peripheral vessels

Hardebo , J. E. 1992. Influence of impulse pattern on noradrenaline release from sympathetic nerves in cerebral and some peripheral vessels. Acta Physiol Scand 144 , 333–339. Received 18 June, accepted 7 November 1991. ISSN 0001–6772. Departments of Medical Cell research and Neurology, University of Lund, Lund, Sweden. Earlier findings suggested that the physiological firing rate in sympathetic nerves did not exceed 10 Hz. Later recordings have revealed that this is a net value: impulses are usually not continuous but occur in bursts of high frequencies separated by quiet periods. The effects of continuous and burst-like neurogenic activation in various isolated blood vessels were compared. In the first part of the study changes in vascular tone were registered. Electrical field stimulatory parameters were chosen to give tetrodotoxin-blockable, neurogenic responses. From dose-response experiments in rat caudal artery a net frequency of 6 Hz was chosen, for bursts usually designed as 30 Hz during 0.2 s followed by a quiet period of 0.8 s. In the rabbit ear artery the neurogenic contraction was enhanced by a mean of near 50% during stimulation with bursts. Now appeared a minor phentolamine-resistant portion, which was nor due to release of NPY, 5–HT, histamine or ATP. Also in the rat caudal artery and monkey pial artery a significant enhancement of contraction was seen during burst stimulation, whereas in the rabbit facial vein no significant difference in dilatation through β-receptor activation was obtained. In vessels that do not normally respond with purely neurogenic contractions/dilatations during continuous stimulation, like pial arteries from the rat and rabbit, not even bursts revealed a neurogenic response. In a second series of experiments the influence of continuous and burst-like nerve activation on the release of [¹⁴C]noradrenaline was studied in monkey, rabbit and rat pial arteries, rat caudal artery and rabbit central ear artery and facial vein. In all vessels except rabbit pial artery a significantly higher release was obtained with burst-like compared to continuous stimulation.     

Ontogeny of intrinsic innervation in the human kidney

We aimed to define, for the first time, the ontogeny of intrarenal innervation and to assess the distribution and nature of parenchymal nerves in the human fetal kidney. Our material consisted of routinely-processed renal tissue sections from 17 human fetuses, six of 20–24 gestational weeks (gw) and 11 of 25–40 gw, and three adults. We used immunohistochemistry with antibodies to the pan-neural markers neuron-specific enolase (NSE), neurofilaments (NF), PGP9.5, S100, and the adrenergic marker tyrosine hydroxylase (TH). NSE-, NF-, S100-, and PGP9.5-positive nerves, associated with arterial and venous vasculature, were identified in the renal cortex from 20 gw onwards, and their density appeared to increase with gestation, reaching adult levels at 28 gw. Most of the intrarenal nerves were TH-positive. Nerve fibers extended from the corticomedullary region to the outer cortex, reaching the renal capsule in the 3rd trimester. In detail, NSE-, NF-, S100-, PGP9.5-, and TH-immunoreactive fibers were observed in close apposition to the renal artery and its branches, occasionally reaching the afferent and efferent arteriole (3rd trimester). Nerve fibers were detected in close apposition to the juxtaglomerular apparatus in the 2nd and 3rd trimesters. In the renal medulla, NSE-, PGP9.5-, S100-, and TH-positive nerve fibers were detected close to tubular cells as early as 20 gw. However, their density gradually decreased during the 3rd trimester, and they were not observed in the medulla of the adult kidney. In conclusion, the human fetal kidney appears richly innervated during the 2nd and 3rd trimesters. There is a progressive increase in the density of parenchymal nerve fibers towards term from the corticomedullary region to the cortex. Most intrarenal nerves are adrenergic and have a predominant perivascular distribution, implying that renal innervation plays an important functional role during intrauterine life.     

去睾丸大鼠骨形态计量学的研究

目的：探讨4月龄雄性大鼠去睾丸后骨量的变化，重点比较松质骨和皮质骨骨代谢的变化。方法：20只4月龄SD雄性大鼠，随机分为假手术组（A组）和去睾丸组（B组），同等条件下饲养90d后，取腰椎和胫骨中段行不脱钙制片进行骨形态计量学观察。结果：去睾丸组与假手术组比较，前者腰椎松质骨吸收增加、骨形成下降（P〈0．05），出现明显骨质疏松；皮质骨外膜的骨形成动态参数如矿化沉积率、骨形成率下降（P〈0．05），内膜骨形成和吸收均有增加趋势。结论：去睾丸90d能使大鼠松质骨出现骨质疏松，皮质骨丢失不如松质骨显著。松质骨对去睾丸敏感性比皮质骨高。     

Structure,innervation, and age-associated changes of mouse forearm muscles

In spite of a decline in muscle strength with age, the cause of the overall decrease in motor performance in aged mammals, including rodents, is incompletely understood. To add clarity, the gross organization, innervation, histochemical fiber types, and age-associated changes are described for mouse forearm muscles used in a variety of motor functions. The anterior (flexor) and posterior (extensor) forearm compartments have the same arrangement of muscles and gross pattern of innervation as the rat. Two primary histochemical fiber types, fast/oxidative/glycolytic (FOG) and fast/glycolytic (FG), with characteristic hitsochemical staining patterns were observed in all forearm muscles. Additionally, there was a small population of slow/oxidative (SO) fibers confined to the deep region of a single muscle, the flexor carpi ulnaris (FCU). Between 18 and 26 months the FCU muscle displayed fibers with morphological features distinct from earlier ages. Fibers displayed a greater variation in size, a loss of their uniform polygonal shape, and a dramatic increase in clumps of subsarcolemmal mitochondria, lysosomes, and lipofuscin granules. Many of the fibers had a distinctly atrophic, angular shape consistent with recent denervation. Morphometric analyses of the FCU's source of innervation, the ulnar nerve and one of its ventral roots (C8), were consistent with the denervation-like changes in the muscle fibers. Although, there was no net loss of myelinated axons between 4 and 26 months of age, there was a significant increase in the density of degenerating cells in both the ulnar nerve and ventral root C8. © 1993 Wiley-Liss, Inc.     

The sympathetic innervation of the internal anal sphincter and rectum in the cat

The distribution of the sympathetic innervation to the internal anal sphincter (IAS) and rectum and the occurrence of different types of adrenergic receptors in the two organs were investigated in anaesthetized cats. Anal pressure and rectal motility were recorded by a manometric and a volumetric method respectively. Division of both the hypogastric nerves (HGN) and the lumbar colonic nerves (LCN) reduced the anal pressure by 46 +/- 6% of the resting pressure (40.9 +/- 6.4 mmHg) and consistently increased rectal motility. Efferent electrical stimulation of the HGN as well as the LCN elicited a contraction in the anus and the rectum, which, at maximal stimulation, caused the anal pressure to reach a similar level to that recorded before division of these nerves. After injection of phentolamine the anal contraction was abolished, whereas the rectal contraction was either abolished or converted to a beta-adrenergic relaxation. Propranolol caused increased rectal contraction in response to stimulation of the HGN and the LCN, whereas the anal contraction was unaffected. The results imply that the sympathetic nerves exert a tonic excitatory effect on the IAS and a dual effect on the rectum in the cat. The results also indicate that sympathetic fibres to the IAS are conveyed in both the HGN and the LCN. Inhibitory beta-adrenergic receptors seem to be of minor importance in regulating anal pressure.     

Cutaneous innervation of the human face as assessed by skin biopsy

The morphology of cutaneous sensory and autonomic innervation in human trigeminal territory is still unknown. The aim of this study is to describe facial cutaneous innervation using skin biopsy. This new tool could be useful in understanding the mechanisms underlying several facial pain conditions. In 30 healthy subjects, we quantified epidermal nerve fibers (ENFs) and dermal myelinated fibers (MFs) in V1, V2 and V3, using indirect immunofluorescence and confocal microscopy applied to 2‐mm punch skin biopsies from areas adjacent to the eyebrow, upper and lower lip. Using selective markers, we also evaluated the distribution of peptidergic, cholinergic and noradrenergic fibers. Facial skin appeared abundantly innervated and rich in annexes. The ENF density decreased and the MF density increased, moving from the supraorbital to the perioral skin. Noradrenergic sudomotor fibers were particularly and constantly expressed compared with other body sites. Distribution of vasoactive intestinal peptide‐immunoreactive (VIP‐ir) fibers appeared peculiar for their constant presence in the subepidermal neural plexus – in close contact, but without colocalization with calcitonin gene related peptide (CGRP) and substance P (Sub‐P)‐ir fibers. Finally, in perioral skin samples, we observed striated muscle fibers with their motor nerves and motor endplates. Our work provides the first morphological study of human facial cutaneous innervation, highlighting some unique features of this territory. Quantification of unmyelinated and myelinated fibers on 2‐mm punch biopsies appeared to be feasible and reliable. Facial skin biopsy may be a new approach with which to study and to better characterize facial pain syndromes.     

Lateral costal branch of the internal thoracic artery

The lateral costal branch (LCB) of the internal thoracic artery (ITA) was studied because its presence sometimes may reduce the blood flow of the ITA when it is used for myocardial revascularization (Singh and Sosa, 1981). The ITA of 90 cadavers of adults of both sexes, whose ages ranged from 20 to 84 years, was studied after neoprene latex injection to determine its incidence, its relation to the phrenic nerve and first rib, its diameter, and the distance between the origin of the ITA and the origin of the LCB. We found the LCB in 16.6% of the cases, with bilateral presence in 5.5%. Unilateral rightside incidence was 11.1%, and left unilateral incidence was not observed. The LCB originated from the ITA in all cases, with a distance of origin along the ITA of 23.7 + 6.7 mm on the right side and 29.5 ± 6.4 mm on the left side. The mean diameter of the LCB was 1.7% ± 0.8 mm. © 1993 Wiley-Liss, Inc.     

Comparative anatomy and histology of the radial artery and the internal thoracic artery

Summary Anatomical characteristics of the radial a. were compared to those of the internal thoracic a., considered as a gold standard in coronary surgery. The length, the diameter, the collateral distribution and the wall thickness of these two arteries were studied comparatively. In addition, a comparative histological analysis was carried out. Anatomical and histological characteristics of these two arteries have important implications for coronary artery bypass.

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Anatomie et histologie comparative de l'artère radiale et de l'artère thoracique interneIntérêt pour les pontages coronaires

Résumé Les caractéristiques anatomiques de l'a. radiale ont été comparées à celles de l'a. thoracique interne, cette dernière étant considérée comme le greffon de référence en chirurgie coronaire. La longueur, le diamètre, les branches collatérales et l'épaisseur pariétale de ces deux artères ont été étudiées. Une analyse histologique comparative a également été effectuée. Les caractéristiques anatomiques et histologiques de ces deux artères ont d'importantes implications pour la chirurgie de pontage coronaire.

     

The development of synaptophysin immunoreactivity in the human sympathetic ganglia

Using an indirect immunohistochemical method, synaptophysin immunoreactivity (SYN-IR) has been studied in cryostat sections of stellate and thoracic ganglia in human fetuses, neonates, infants and adults. In the course of development, a progressive increase in SYN-IR in axonal terminals and around nerve cells was demonstrated. In contrast, large clusters of small intensely fluorescent (SIF) cells and paraganglionic cells increased in number in fetuses and premature neonates at 24-25 weeks. Such SIF cell clusters varied in form and often occurred at pole or subcapsular areas of sympathetic ganglia close to blood vessels or paraganglia. With increasing gestational age and during infancy, a decrease in sizes of SIF cell groups and paraganglionic cells as well as changes in their distribution were found. The results show that the amount and distribution of SYN-IR is temporally related to the maturation and functional activity of human sympathetic ganglia neurons. It was suggested that numerous SIF cells and paraganglia in human prenatal sympathetic ganglia were both indicative of incomplete cell migration and an important source of regulation of ganglionic microcirculation under the conditions of relative hypoxia and immature nervous regulation.     

Clinical anatomy of internal thoracic artery branches

The broad clinical utilization of the internal thoracic artery (ITA), including the role of its branches in supplying circulation to the sternum, requires explicit anatomic knowledge of this vessel. Fifty‐six ITAs (28 right, 28 left) were dissected from their point of origins after injection with a mixture of contrast medium and latex after perfusion with saline and immersion in 4% formaldehyde. All ITA branches were studied according to their course, size, and distribution within intercostal spaces with the aid of an operating microscope. The branches were divided in two main groups: proper (solitary) branches and common trunks. The proper branches consisted of four types: sternal, perforating, intercostal, and mediastinal. The four types of common trunks were: sternal/perforating, sternal/intercostal, perforating/intercostal, sternal/perforating/intercostal. Points of most frequent origin from main trunk of the vessel were established for each type. Mean external diameter of proper branches was 0.72 mm and common trunks was 1.06 mm. Mean length of common trunks was 3.0 mm. Those parameters (adequate diameter and length) allow for ligation of the common trunks close to the ITA so that their points of division can be preserved. This fact is crucial for creation of collateral blood supply to the sternum after bilateral ITA mobilizations. Clin. Anat. 12:307–314, 1999. © 1999 Wiley‐Liss, Inc.