Organization of motoneurons innervating the axial musculature of the brown caiman (Caiman crocodilus fuscus)

The primary divisions of the spinal nerve in the brown caiman characteristically show the following features: (1) the medial ramus was lies in the thoraco-lumbar and caudal regions, and (2) the first cervical and hypoglossal nerves form a single nerve complex from which the ventral and dorsal rami extend. Intramuscular injections of horseradish peroxidase (HRP) established the positions of motoneurons whose axons followed the primary rami. In the ventral horn of the thoracic and caudal spinal cord, the motoneurons of the medial ramus lie ventrally. These motoneurons lie between the epaxial and hypaxial motoneurons. At the spinomedullary junction, the pools of motoneurons innervating the infrahyoid, lingual, and dorsal muscles have a somatotopic organization similar to that observed in the thoraco-lumbar and caudal regions. Thus clear somatotopic organization of the motoneurons that innervate the axial musculature exists at all spinal levels. © 1994 Wiley-Liss, Inc.     

Nerves and nerve plexuses of the human vertebral column

The origin, distribution, and termination pattern of nerves supplying the vertebral column and its associated structures have been studied in the human fetus by means of an acetylcholinesterase whole-mount method. The vertebral column is surrounded by ventral and dorsal nerve plexuses which are interconnected. The ventral nerve plexus consists of the nerve plexus associated with the anterior longitudinal ligament. This longitudinally oriented nerve plexus has a bilateral supply from many small branches of the sympathetic trunk, rami communicantes, and perivascular nerve plexuses of segmental arteries. In the thoracic region, the ventral nerve plexus also is connected to the nerve plexuses of costovertebral joints. The dorsal nerve plexus is made up of the nerve plexus associated with the posterior longitudinal ligament. This nerve plexus is more irregular and receives contributions only from the sinu-vertebral nerves. The sinu-vertebral nerves originate from the rami communicantes and, in the cervical region, also from the nerve plexus of the vertebral artery. Thick and thin sinu-vertebral nerves are found. Most frequently three types of thick sinu-vertebral nerves are observed, i.e., ascending, descending, or dichotomizing ones. Finally, the distribution of the branches of the ventral and dorsal nerve plexuses and of the sinu-vertebral nerves is described.     

Systemic arterial blood supply to the trachea and lung in sheep

We studied the systemic arterial blood supply to the trachea and lung in adult sheep. After anesthesia, sheep were exsanguinated and then studied by intra-arterial injection of one of the following materials: saline containing dyes of various colors (n = 24), Microfil (n = 8), or Batson's solution (n = 6). The systemic blood supply to the cervical trachea originated from the two common carotid arteries via three to four small branches (rami tracheales cervicales) on each side. A segment of the thoracic trachea between the thoracic inlet and the origin of the tracheal bronchus (bronchus trachealis) and the bronchial tree of the right cranial lobe (lobus cranialis dexter) were supplied by the tracheal bronchial branch (ramus bronchalis trachealis), which originated from the brachiocephalic trunk (truncus brachiocephalicus). A portion of thoracic trachea between the origin of the tracheal bronchus and the tracheal carina was supplied by the thoracic tracheal branch (ramus trachealis thoracica), arising from the bronchoesophageal artery (arteria bronchoesophagea) or directly from the thoracic aorta. The bronchial branch (ramus bronchalis) originated from the bronchoesophageal artery, and its branches supplied the remainder of the bronchial tree. At 120 cmH2O pressure (n = 8), the bronchial branch contributed approximately 50% and the other two approximately 25% each of the total tracheobronchial blood flow. These three branches also supplied the visceral pleura. Additionally, several small vessels (rami pleurales pulmonales) originated from the esophageal branch (ramus esophagea) of the bronchoesophageal artery, traversed the pulmonary ligaments, and supplied the visceral pleura.     

The 'loge de Guyon'. A contribution to the clinical anatomy of the human hand

In 40 hands of adults the 'loge de Guyon', a narrow bounded area within the proximal hypothenar region, has been dissected to realize an exact determination of the important characteristics of size. Beside measurements of the wall structures in the region of the pisiform bone, the hook of hamate and the entrances of the loge, variations of muscles and the position of the ulnar artery and nerve with their terminal branches have also been examined. The deep palmar branch of the ulnar artery crosses the rami of the ulnar nerve on the palmar side in 65% of cases. The branch of the artery crosses on the dorsal side in 30% and in 5% the ramus profundus of the ulnar artery runs between both terminal branches of the ulnar nerve. The clinical significance of the loge is emphasized, whereas the irregular nomenclature in the national and international literature is discussed in detail.     

Early development of the facial nerve in the chick embryo with special reference to the development of the chorda tympani

The development of the facial nerve from Hamburger and Hamilton stage 17 to stage 28 is described in chick embryos by means of a new immunochemical nerve staining method that uses an antineurofilament protein (NFP) antibody. A postspiracular branch and an unknown transient posterior branch beneath the ostocyst were observed at stage 17. At stage 19, the primordia of the r. palatinus were observed. A prespiracular branch appeared at stage 21, and with the postspiracular nerve, it made a loop encircling the spiracle (spiracular loop). The first primordium of the ramus (r) hyoideus and transient rami (rr) dorsales appeared around stage 23. At stage 25, the chorda tympani was first observed to arise from the ventral end of the spiracular loop. At stage 26, a communicating branch, connexus cum nervo glossopharyngeo, was found along with the vena (v) capitis lateralis. The rr. dorsales seemed to represent the r. supratemporalis in lower animals. The communicating branches around the v. capitis lateralis seemed to correspond to the cutaneous nerve communications between the branchial nerves frequently encountered in Amphibia. It was found that the chorda tympani becomes a prespiracular nerve for the most part in the chick by the reduction of the postspiracular component of the spiracular loop. Thus, the nerve differs markedly from that in other animals, which is postspiracular. This difference explains the different passage of this nerve in the chick as compared with other amniotes.     

电刺激大鼠脊神经皮支对远距离机械感受单位电活动的影响

实验采用分离神经细束的方法,观察逆行电刺激大鼠脊神经背侧皮支后,在相距较远的神经细束上记录到的Aδ和C类机械感受单位电活动的变化。刺激T9脊神经背侧皮支,在T12神经细束上记录到59.3%（16/27）的Aδ和71.2%(37/52）的C类单位在刺激后90～120s放电显著增加。刺激T8脊神经背侧皮支,在T12神经细束上记录到47.8%(11/23）的Aδ单位和36.6%(15/41）的C类单位在刺激后120～150s放电显著增加。大多数单位（18/23）的机械感受阈值在电刺激远距离脊神经背侧皮支后降低。结果表明,逆行电刺激外周感觉神经,可以使相距较远的Aδ和C类机械感受单位致敏,其传入放电增加。     

刺猬的皮肌及其神经支配

刺猬的皮肤,包括皮肤肌和皮下脂肪,是一个质量很大的器官,平均占体重43形,最多可达57％以上。刺猬的皮肌,如果不是动物界中最发达的,也是非常发达的,尤其环状皮肌带约占体重11％(赵以炳等1958)。在功能上,刺猬的皮肌是重要的生理性体温调节器官,背面带针刺的部分有保温御寒作用,腹部有散热机能(赵以炳等1950a)。清醒的刺猬当遇到强敌或其它干扰时,常蜷缩成带剌的球。不活动的冬眠刺猬也取同样姿势,以防侵害。可以说,蜷缩是一种主动的保护性行为,这种强烈的蜷缩主要是由于环状皮肌带持续有力的收缩。尤其令人惊奇的是冬眠时的蜷缩,这是在一般生理活动明显降低的     

Review of spino-occipital and spinal nerves in Tetraodontiformes,with special reference to pectoral and pelvic fin muscle innervation

The spino-occipital nerve (SO) and ventral rami of the spinal nerves (SV) in 10 tetraodontiform families and 5 outgroup taxa were examined, with special reference to pectoral and pelvic fin muscle innervation. Compared with the outgroup taxa, tetraodontiforms were characteristic in having SO3 + SV1 (SO3 in tetraodontids) that gave off several lateral subbranches to the pectoral fin base and SO participation in infracarinalis anterior innervation. SO and SV1 were connected with one another (6 patterns) before entering the pectoral fin muscles in most species, including the outgroup taxa, resulting in the participation of SV1 in the innervation of almost all of the pectoral fin muscles. SO3 + SV1 was present in all tetraodontiforms (except in 2 tetraodontids having only SO3) and the outgroup taxa, an upper dorsal branch uniformly extending dorsally into the pectoral fin base. The pectoral fin base also received a branch ventrally, but its identity differed (participation or nonparticipation of SV2). SV1 alone constituting the branch was a derived condition occurring in Aracanidae, Ostraciidae, Tetraodontidae, Diodontidae, and Molidae. No strong characters supporting a tetraodontiform sister group were recognized among the spino-occipital nerve and ventral rami of spinal nerves.     

Innervation pattern of the gill arches and gills of the carp (Cyprinus carpio)

The innervation pattern of the respiratory gill arches of the carp (Cyprinus carpio) is described. The gill region is innervated by the branchial branches of the glossopharyngeal and vagal nerves. Each branchial nerve divides at the level of or just distal to the epibranchial ganglion into: 1) a pretrematic branch, 2) a dorsal pharyngeal branch, and 3) a posttrematic branch. The dorsal pharyngeal branch innervates the palatal organ in the roof of the buccal cavity. The pretrematic and posttrematic branches innervate the posterior and anterior halves, respectively, of the gill arches bordering a gill slit. Each branch splits into an internal and an external part. The internal bundle innervates the buccal side of the gill arch, including the gill rakers. The external bundle terminates in the gill filaments. The epibranchial motor branch, a small nerve bundle containing only motor fibers, circumvents the ganglion and anastomoses distally with the posttrematic branch. The detailed course and branching patterns of these branches are described.     

Thenar and hypothenar muscles and their innervation by the ulnar and median nerves in the human hand.

The thenar and hypothenar muscles as well as their supplying nerves were analyzed with an improved dissecting method. Among the four thenar muscles, the m. abductor pollicis brevis (AbPB) has a separate muscle belly, whereas the m. opponens pollicis (OP), the superficial and deep heads of the flexor pollicis brevis (sFPB and dFPB), and the adductor pollicis (AdP) are fused with each other to make a single mass (deep thenar muscle group). These muscles are innervated by branches of the recurrent nerve and the accessory recurrent nerve from the median nerve as well as by terminal branches of the deep branch (ramus profundus) of the ulnar nerve. These three nerves frequently form a loop within the deep thenar muscle group (thenar loop), and a branch to the OP and one to deep parts of the sFPB often make a smaller loop (intrathenar loop), whereas the AbPB receives a separate nerve branch. Among the hypothenar muscle, the m. abductor digiti minimi and the m. flexor digiti minimi brevis are fused with each other, and their supplying nerves frequently form a loop in these muscles (intrahypothenar loop), whereas the m. opponens digiti minimi is separated from the others and receives a separate nerve branch. In the distribution pattern of supplying nerves to the thenar and hypothenar muscles, we find regularities in that they branch off in a regular manner from the ulnar and the median nerve, and that nerve branches to those muscles with fused bellies frequently communicate with each other to make loops.     

Separate populations of primary sensory neurons project to the splanchnic nerve and thoracic spinal nerve rami of the rat. A fluorescent double labelling study

Using fluorescent double labelling technique with one tracer applied to the greater splanchnic nerve and a second to the ventral or dorsal spinal nerve ramus at the T9 level, it was shown that two separate populations of sensory nerve cell bodies in the T9 dorsal root ganglion were projecting to the splanchnic nerve and spinal rami, respectively. Only two double labelled cells were detected. The results support the theory that spinal and/or supraspinal interactions and not dichotomizing sensory axons are responsible for referred pain.     

The superior laryngeal nerve and the superior laryngeal artery

Length, diameter and anastomoses of the nervus vagus and its ganglion inferius were measured 44 halved heads. On the average, 8.65 fiber bundles of the vagus nerve leave the retro-olivary area. In the area of the jugular foramen is the near superior ganglion of the 10th cranial nerve. In this area were found 1.48 (mean value) anastomoses with the 9th cranial nerve. 11.34 mm below the margo terminalis sigmoidea branches off the ramus internus of the accessory nerve which has a length of 9.75 mm. Further anastomoses with the 10th cranial nerve were found. The inferior ganglion of the 10th nerve had a length of 25.47 mm and a diameter of 3.46 mm. Five mm below the ganglion the 10th nerve had a width of 2.9 and a thickness of 1.5 mm. The mean length of the superior sympathetic ganglion was 26.6 mm, its width 7.2 and its thickness 3.4 mm. In nearly all specimens anastomoses of the superior sympathetic ganglion with the ansa cervicalis profunda and the inferior ganglion of the 10th cranial nerve were found. The superior laryngeal nerve branches off about 36 mm below the margo terminalis sigmoidea. The width of this nerve was 1.9 mm, its thickness 0.8 mm on the right and 1.0 mm on the left side. The division in the internal and external rami was found about 21 mm below its origin. Between the n. vagus and thyreohyoid membrane the ramus internus had a length of 64 mm, the length of external ramus between the vagal nerve and the inferior pharyngeal constrictor muscle was 89 mm. Its mean length below the thyreopharyngeal part was 10.7 mm, 8.6 branchlets to the cricothyroid muscle were counted. The superior laryngeal artery had its origin in 80% of cases in the superior thyroideal artery, in 6.8% this vessel was a branch of the external carotid artery. Its average outer diameter was 1.23 mm on the right side and 1.39 mm on the left. The length of this vessel between its origin and the thyreohyoid membrane was 34 mm. In 7% on the right side and in 13% on the left, the superior laryngeal artery reached the larynx through a foramen thyreoideum. Ranges of diameters and lengths of vessels and nerves in the larynx are given.     

Comparative anatomical study of the autonomic cardiac nervous system in macaque monkeys

The main aim of this study was to clarify the general morphology of the autonomic cardiac nervous system in macaque monkeys. A submacroscopic comparative anatomical study of the autonomic cardiac nervous system was performed by examining 22 sides of 11 bodies of four species of macaque monkeys, including some previously unreported species (pig-tailed and stump-tailed monkeys), under a surgical stereomicroscope. The following results were obtained. 1) The basic arrangement of the autonomic cardiac nervous system is constant in all examined macaques. 2) A superior cardiac nerve originating from the superior cervical ganglion was not observed, whereas the thoracic cardiac nerve originating from the sympathetic trunk/ganglia under the cervicothoracic ganglion was rarely observed in all the examined macaques. 3) The main cardiac nerve is the middle cardiac nerve originating from the middle cervical ganglion, similar to the situation in humans. 4) Although the superior, inferior, and thoracic cardiac branches of the vagus nerve were consistently observed, the left thoracic cardiac branch is rarely absent because of its lower origin to the heart. 5) The cranial autonomic nerves tend to distribute into the heart medially (arterial porta), and the caudal autonomic nerves tend to distribute into the heart laterally (venous porta). To comprehend the comparative morphological and evolutionary changes more completely, these results were compared with our previous studies and some references. Consequently, differences in the sympathetic cardiac nerves of macaques and humans are recognized, in spite of the similar morphologies of the vagal cardiac branches. These differences include the composition of the cervicothoracic ganglion, the lower positions of the middle cervical and cervicothoracic ganglia, and the narrow range for the origin of the cardiac nerves in macaques compared to that in humans.     

Arrangement and innervation of the iliocostalis and longissimus muscles of the brown caiman (Caiman crocodilus fuscus: Alligatoridae, Crocodilia).

The axial musculature of the brown caiman was investigated in detail with particular attention to the nerve supply, using a binocular stereomicroscope. Due to the prominent development of the longissimus (Lo) and the iliocostalis (IC) muscles of the caiman, the pattern of distribution of the spinal nerves in the body wall was unique; there also was less differentiation of the external intercostalis. There were four primary divisions of the spinal nerves in the thoracic region of the caiman, from ventral to dorsal: the intercostal nerve, the IC nerve, the Lo nerve, and the dorsal main trunk. Thus, the classic concept of the organization of the spinal nerves may not be suitable for the caiman. These findings suggest that evolutionary changes in the dorsolateral axial musculature have brought about the rearrangement of the organization of the spinal nerves. In addition, each clearly segmented myotome of the Lo and IC was innervated by more than two segments of the spinal nerves (plurisegmental innervation). The manner of formation of the myotome and its innervation is discussed from the viewpoint of comparative and developmental anatomy.     

Pattern formation of the sensible nerves in the hand of mouse embryos with special reference to the posterior-anterior developmental gradient

The development of the sensible innervation of the hand was investigated. For this reason normal forelimbs and limb bud cultures from 12- to 14-day-old mouse embryos were stained in toto using the cholinesterase technique. The dorsal side of the hand is mainly innervated by sensible branches of the radial and the musculocutaneous nerve, which penetrate the fascia in the region of the elbow. From here they grow in a distal direction forming the dorsal digital nerves. On the ventral side the median nerve grows in a subfascial compartment towards the palmar side of the hand. While passing the wrist the median nerve exhibits a frayed appearance. A net of branching and anastomosing small nerve fibre bundles is visible. This implies that on the palmar side of the metacarpal region of the hand-plate no specific highways for the growing nerve fibres exist. From late day 12 to early day 14 of embryonic development this diffuse nerve net is organized. In a posterior-anterior (ulnoradial) developmental gradient the common palmar digital nerves were formed, and these nerves divide at their tip into the proper digital nerves. However, the proper digital nerves again follow special pathways during their outgrowth.     

Cutaneous nerves of the embryonic chick wing do not develop in regions denuded of ectoderm

Peripheral nerves travel to their targets along precise routes, and it is likely that different cues provide guidance at different stages of the journey. In a developing chick limb, the cutaneous nerve fibres follow at first deep mixed nerve trunks, in company with motor axons; they branch from these trunks at predictable points and approach the skin; they then ramify profusely to form a plexus at a precisely defined depth beneath the ectoderm, at exactly the same level as the blood vascular plexus. To analyse the role of signals from the target patch of skin in regulating cutaneous nerve development, we have ablated patches of dorsal wing ectoderm using short-wave ultraviolet irradiation at E4 (embryonic day 4), approximately one day before nerves grow into the limb bud. The irradiated patches remain denuded of ectoderm for more than a week, by which time the cutaneous nerve plexus on the contralateral control side is well developed and can be revealed by whole-mount silver staining. Where the ectoderm has been ablated, no cutaneous nerve plexus forms, and the nerve branches that normally would have diverged from the neighbouring mixed nerve trunk to innervate the missing patch of skin are absent - ab initio, apparently. The routes of the mixed nerve trunks are not affected. Partial ablation of the territory of a cutaneous nerve branch often leads to loss of the whole nerve branch; the intact skin territory thus left vacant is invaded by ramifications from the remaining cutaneous branches, as expected if the normal extent of a cutaneous nerve's territory is regulated by competition. Where there is an ectodermal lesion, cutaneous innervation stops precisely at its boundary, even though the vascular plexus extends for some distance beyond this margin, beneath the denuded surface. The data suggest that the embryonic skin is required firstly to trigger divergence of cutaneous nerve branches from the mixed nerve trunks, and secondly, once the nerve fibres have reached the skin, to supply a trophic cue (probably NGF) encouraging growth of a plexus; at the same time, the embryonic skin generates a signal inhibiting nerves from approaching closer than about 70 microns to the surface.     

刺猬胸前神经传入活动的来源及皮层代表区分布

为探讨冬眠刺猬皮肌的紧张性控制,本工作研究了支配皮肌的胸前神经(VTN)的传入活动的来源和皮层代表区的分布。VTN的传入冲动来自皮肌本体感受器,传入纤维径C_6—T_2背根入脊髓,与同部位的皮肤感觉相分离,后者经相应节段的皮神经传入。电刺激VTN引起的皮层诱发电位反应位于新皮层外侧面的中间部,相当于Woolsey的S-Ⅱ区内,与桡神经和坐骨神经的代表区有重叠,而在S-Ⅰ区没有记录到反应。     

Experimental studies on the afferent innervation of the cricothyroid muscle in dogs

The cricothyroid muscle in dogs received branches from two independent nerves, namely the external ramus of the cranial laryngeal nerve and the pharyngeal branch of the vagus. Classical spindles are infrequent in the muscle. Atypical forms of sensory endings were identified. Two end-plates were frequently met with on a single extrafusal fibre. Sectioning of the external ramus of the cranial laryngeal nerve was followed by degeneration of spindles. Intact axons detected up to 6 months after operation are probably derived from the pharyngeal branch of the vagus. Chromatolytic changes occurred in the ipsilateral dorsal vagal nucleus and the capsulated ganglion at the entry of the nerve into the muscle. Chromatolysis occurred in the intramuscular ganglion cell rows and in neurons of the ipsilateral nodose ganglion. Morphological alterations were more pronounced in the ipsilateral medial column of the nucleus ambiguus. No changes were observed in the somata of the mesencephalic nucleus.