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.

The extrinsic innervation of the pelvic organs in the female rat

The extrinsic innervation of the pelvic organs in neonatal and adult female rats is described. Mainly an in toto acetylcholinesterase method is used; moreover, acetylcholinesterase is demonstrated in sections. The hypogastric plexus is defined as the nerve plexuses caudal to the inferior mesenteric ganglia comprising the uterine cervical ganglia and various smaller ganglia. The origin of the hypogastric plexus is formed by the hypogastric nerves, bundles of nerve fibers from the lumbar and cranial part of the sacral sympathetic trunks, bundles of nerve fibers from the inferior mesenteric ganglia and the pelvic nerves. The origin of the caudal part of the hypogastric plexus is also constituted by the pudendal nerves. The uterine nerves are derived from the ovarian nerves, the uterine cervical ganglia, the hypogastric nerves and the lumbar sympathetic trunks. The nerves to the urinary bladder are derived from the ganglionated nerve plexuses in the mesometrium as well as from the uterine cervical ganglia. The vaginal nerves are derived from the uterine cervical ganglia, the ganglionated nerve plexus in the mesometrium and the pudendal nerve. The rectal nerves are derived from the ganglionated inferior mesenteric plexus, the uterine cervical ganglia and the pudendal nerves. The hypogastric plexus in the rat is in many respects more complex than is known from the literature. These anatomical data are relevant for instance to experimentators who use the pelvic autonomic plexuses in the rat as a model system for the analysis of autonomic neuronal regulation systems in mammals.

The extrinsic innervation of the abdominal organs in the female rat

The extrinsic innervation of the abdominal organs in neonatal and adult female rats is described. Mainly an in toto acetylcholinesterase method was used; moreover, formaldehyde-induced fluorescence and acetylcholinesterase were demonstrated in sections. The major splanchnic nerve has its origin in the ninth and tenth thoracic sympathetic trunc ganglia. In the major splanchnic nerve a suprarenal ganglion is present. Sometimes the minor splanchnic nerve, arising from the tenth thoracic ganglion, joins the distal part of the suprarenal ganglion. The left and right major splanchnic nerves join the left and right celiac ganglia in the plexus. The left celiac ganglion is always bigger than the right one. The celiac plexus and the celiac inferior mesenteric plexus are joined by the intermesenteric plexus. Para-aortic nerves, originating in the caudal part of the thoracic sympathetic truncs, also join the abdominal prevertebral plexuses. The lumbar splanchnic nerves, not symmetrical in their origin, join the prevertebral plexuses and give off branches to the abdominal organs. The suprarenal glands receive bundles of nerve fibers, sometimes ganglionated, from the suprarenal ganglion. The kidneys are innervated from the celiac plexus, the upper lumbar splanchnic nerves and the intermesenteric plexus. The ovarian nerves are derived from the celiac plexus, the intermesenteric plexus and the upper lumbar splanchnic nerves. Bundles of nerve fibers run from the suprarenal ganglion in the celiac plexus in the direction of the suspensory ligament of the ovary. In many respects this description is at variance with existing literature on the autonomic innervation in the rat. These differences with the standard literature are relevant to those workers engaged in experiments on the sympathetic innervation of abdominal viscera.

The innervation of the spinal dura mater: anatomy and clinical implications

The nerves supplying the spinal dura mater were studied in four human foetuses (16-22 weeks) with the acetylcholinesterase in toto staining method. The ventral spinal dura contains a dense, longitudinally oriented, nerve plexus, which receives its contributions from: (I) the sinuvertebral nerves, (II) the nerve plexus of the posterior longitudinal ligament, (III) the nerve plexus of radicular branches of segmental arteries. Dorsal dural nerves are much smaller in number, do not form an evident plexus and do not reach the medial region of the dorsal dura. The dorsal nerves are derived from the ventral dural plexus at the level of the "intersleeval" parts of the dura mater. The ventral dural nerves may extend up to eight segments, with a great amount of overlap between adjacent nerves. This may provide an anatomical substrate for the understanding of extrasegmentally referred dural pain. The curled bundles of nerve fibres of pathways (I) and (II) provide an adequate adaptation to displacements of the spinal dura mater during flexion and extension. Pathway (III) has not been described before. The described nerve plexuses may be of importance in elucidating the mechanisms of epidural therapies in back pain and peripheral vascular disease.

Pre- and post-ganglionic nerve fibres of the pterygopalatine ganglion and their allocation to the eyeball of rats

The origin, course and distribution of pre- and postganglionic neurons of the pterygopalatine ganglion (PPG) in the rat were studied using acetylcholinesterase staining, wheat germ agglutinin coupled to horseradish peroxidase (WGA-HRP) histochemistry and autoradiography. These methods were used in a selected and planned fashion to reveal details concerning the innervation of the lacrimal gland and portions of the eye. The PPG in rats consists of a rostral triangular portion and additional perikarya surrounding the distal part of the major petrosal nerve. Fibres from the superior cervical ganglion (SCG) reach the PPG via the inferior petrosal sinus. Application of WGA-HRP was made after transections: (1) rostral to the PPG; and (2) caudal to the PPG. The first of these applications labelled mainly fibres in the PPG; the second application labelled preganglionic parasympathetic brainstem neurons dorsolateral to the facial nucleus (i.e. the lacrimal nucleus), rostral cells in the SCG and trigeminal sensory fibres. WGA-HRP injections of the lacrimal gland, the conjunctiva and the anterior chamber of the eye all labelled cells in different parts of the PPG. This means that the PPG contains sensory and sympathetic nerve fibres and that the PPG has a topographical organisation along the rostrocaudal axis. Isotope injections of the PPG anterogradely labelled fibres passing through the ciliary ganglion that innervated the conjunctiva, the limbus and parts of the choroid.

An acetylcholinesterase method for in toto staining of peripheral nerves

Stomach, small intestine, uterus, urinary bladder, vagina, mesentery, mesometrium and joint capsule of rats, gall bladder, cystic duct and bile duct of dogs and uteri of young children are stained in toto.

PROCEDURE

Tissue is perfused with saline containing hyaluronidase, then pinned on a flat layer of Paraplast and fixed for 24 hr in cold sucrose formol solution. Stomach, urinary bladder and gall bladder are also fixed in toto. Rinse for 2 days in cold 0.22 M sucrose in a sodium cacodylate buffer pH 7.2. Incubate in medium consisting of 60 mM acetate-buffer pH 5.0 or pH 5.6 (for human material only), 2 mM acetylthiocholine iodide, 15 mM Na citrate, 3 mM Cu sulphate, 0.5 mM K3Fe(CN)6, 5 times 10-4 M iso-OMPA, 1% Triton X 100 at 37C. Rinse in doubly distilled water. Dehydrate in glycerine/water mixtures of increasing glycerine content. Store in glycerine or delaminate under dissecting microscope. Delaminated specimens are mounted on gelatinized object glasses, cleared in xylene and coverslipped with Malinol. Specimens stored in glycerine can be studied microscopically. Stained specimens can also be embedded in Paraplast and sections can be studied after counterstaining.

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.

A retrograde double fluorescent tracing study of the levator palpebrae superioris muscle in the cynomolgus monkey

In the cynomolgus monkey, motoneurons innervating the levator palpebrae superioris muscle form a nucleus within the oculomotor nuclei called the central caudal nucleus. After double fluorescent neuronal retrograde tracing experiments, using fast blue and diamidino yellow as tracers in the levator palpebrae superior muscles, labelled motoneurons (30%) were found in an unpaired central caudal nucleus. Approximately 2% of the labelled motoneurons were double-labelled. The labelled and double-labelled neurons were distributed randomly over the central caudal nucleus, lateralization of populations of levator motoneurons within this nucleus was not observed. The afferent innervation of the levator palpebrae superioris muscle was restricted to the ophthalmic branch area of the gasserian ganglion. Primary afferent labelled neurons were absent from the mesencephalic nucleus of the fifth nerve. Surprisingly, fast blue was also found in the ophthalmic branch area of the contralateral ganglion of Gasser, while diamidino yellow was present only ipsilaterally. About 1% of the afferent labelled neurons were double-labelled. The results reveal that in the cynomolgus monkey the central caudal nucleus is not only topographically but also functionally one nucleus. Afferent innervation of the levator palpebrae superioris muscle is probably bilaterally organized.

Some aspects of the innervation of the abdominal and pelvic organs in the human female fetus

The autonomic abdominal and pelvic nerve plexuses of the human female fetus, were studied by an in toto acetylcholinesterase method in order to obtain data on innervation of the ovaries, uterus, ureter and umbilical cord. The results of this study indicate that in the human fetus there is no anatomical evidence for the concept of a distinct regional nervous supply towards the organs of the abdomen and the pelvis. The ureteric nerve plexus contains small ganglia and the input for this plexus is found along the entire ureter. In the umbilical cord nerve plexuses were found along the blood vessels and urachus up to 30 mm from the umbilicus. The innervation of the skin does not continue in the superficial layer of the umbilical cord.

Silicone rubber tubulization in peripheral sensory nerve reconstruction: an experimental study in rabbits

Silicone rubber (polydimethyl siloxane) tubes are used clinically in peripheral nerve reconstruction. A disadvantage of this procedure is that the material often has to be removed owing to its mechanical properties. The aim of our study was to investigate the healing of reconstructed sensory nerves tubulized by silicone rubber in an animal model. In our experiments, we reconstructed the saphenous nerves in 27 rabbits. In series 1 (n = 12), silicone rubber tubes were slid over a nerve suture without a gap. In series 2 (n = 12), silicone rubber tubes were slid over a 10-mm nerve gap. In series 3 (n = 12), conventional suturing was performed in the collateral saphenous nerves of the animals of the series 1. Epineurial suturing was performed. Three other collateral nonoperated saphenous nerves served as controls. The healing was studied after 3, 6, and 12 months. Morphometric analysis of the regenerating axons was performed by using our new method for quantification of nerve fibers in cross sections stained by immunohistochemistry and using confocal laser scanning microscopy. Data analysis was carried out using a software program especially developed for this purpose. Our results showed in the silicone procedures that at 12 months significantly fewer axons per fascicle area were present compared with conventional suturing. However, mean axon diameters in the distal nerve stump of the silicone procedures did not differ significantly compared with the conventional suturing procedure. The ratio of total axon area to total fascicle area in the distal nerve stumps of the silicone procedure without gap was significantly smaller compared with the conventionally sutured nerve. The percentage outgrowing axons from the proximal nerve stump into the distal one in the silicone rubber procedure without gap was 57%. This was significantly higher than in the silicone rubber procedure with 10-mm gap (48%). However, in conventional suturing, the percentage of outgrowing axons (99%) was significantly higher than in both tubulization procedures. It appeared that tubulization by silicone rubber of sutured nerves without gap did not enhance axon regeneration. Conventional suturing gave significantly better results. If a gap was present, the use of a silicone rubber tube was preferable to non-suturing.

Smith-Lemli-Opitz syndrome diagnosed in a 130-year-old anatomical specimen

The Museum Vrolik collection of human anatomy comprises 360 recently re-described specimens with congenital anomalies. The external findings in one of these specimens, originally described by Willem Vrolik (1801-1863) 130 years ago, were suggestive of Smith-Lemli-Opitz (SLO) syndrome. Cholesterol synthesis was analyzed in skin biopsies, obtained from the suspected SLO specimen and a control specimen. The cholesterol levels in the SLO specimen and in the control specimen were in the proportion of 1 to 45. This confirms the diagnosis in this specimen which, to our knowledge, represents the oldest known case of SLO syndrome.

Aspects of the history of osteogenesis imperfecta (Vrolik's syndrome)

Osteogenesis imperfecta (OI) or Vrolik's syndrome is a heterogeneous group of inherited conditions arising from a variety of biochemical and morphological collagen defects. It was Willem Vrolik, Professor of Anatomy, Pathological Anatomy and Zoology at the Athenaeum Illustre (University of Amsterdam), who described in his Handbook of Pathological Anatomy (1842-1844) and Tabulae ad illustrandam embryogenesin hominis et mammalium, naturalem tam abnormem (1844-1849) a newborn infant with numerous fractures and hydrocephalus. In the Tabulae, having both Latin and Dutch texts, in the Latin text Vrolik used in the heading of Plate 91 the term Osteogenesis imperfecta (in Dutch: gebrekkige beenwording). Vrolik also mentioned that the infant lived three days and that both the parents were suffering from lues universalis at the time of birth. On our reexamination, the whole skeleton appeared poorly mineralised. The fairly large skull exhibited a broad and high forehead, large fontanels, frontal and temporal bossing, shallow orbits, and a protruding occiput. The calvaria consisted of many Wormian bones. The tubular bones, although of normal length and only slightly curved, were very thin, as were the ribs. All the skeletal structures showed one or more fractures and many fractures showed callus formation. In 1998 we re-diagnosed the condition of the specimen as osteogenesis imperfecta type II. Willem Vrolik was one of the first to realize that many skeletal dysplasias were not the result of a postnatal acquired disease, such as "rickets" or "osteomalacia" as many of his contemporaries believed. He thought that it might be due to insufficient intrinsic "generative energy." He substantiated this by stating that in this specimen a primary impairment of ossification is present and not a secondary degeneration. The descriptions given by Willem Vrolik in some of the specimens generated the term Osteogenesis imperfecta and the eponym Vrolik's syndrome for this genetic disorder characterized by increased fragility.

Congenital anomalies in the teratological collection of Museum Vrolik in Amsterdam, The Netherlands. III: primary field defects, sequences, and other complex anomalies

The Museum Vrolik collection of the Department of Anatomy and Embryology of the Academic Medical Center, University of Amsterdam, founded by Gerardus Vrolik (1775-1859) and his son Willem Vrolik (1801-1863), consists of more than 5,000 specimens of human and animal anatomy, embryology, pathology, and congenital anomalies. Recently, the collection of congenital anomalies, comprising 360 specimens, was recatalogued and redescribed according to contemporary morphogenetic views. The original descriptions, if preserved, were compared with the clinical, radiographical, and magnetic resonance imaging findings. In 120 specimens the following midline anomalies, primary field defects, and sequences were diagnosed: holoprosencephaly sequence; aprosencephaly/atelencephaly; cleft lip; Pierre Robin sequence; omphalocele; diaphragmatic hernia; ectopic heart; bladder exstrophy; cloacal exstrophy; caudal dysgenesis; prune belly sequence; sirenomelia; fetal akinesia sequence; and disruption sequences. Polytopic field defects and associations were diagnosed in 25 specimens. We discuss the opinions of Gerardus and Willem Vrolik, who tried to find reasonable explanations for the dysmorphogenetic entities they investigated, rather than accepting the traditional superstitions.

Calcitonin gene-related peptide and substance P immunoreactivity in the monkey trigeminal ganglion, an electron microscopic study

Calcitonin gene-related peptide (CGRP) and substance P (SP) immunoreactivity was examined in neurons of the monkey trigeminal ganglion. Moreover, CGRP- and SP-positive varicose nerve fibers were found, occasionally forming pericellular arborizations around trigeminal somata, which, at light microscopic level, suggested the existence of synaptic contacts. Electron microscopic investigation however, revealed that although these varicose fibers ran in close range of somata and were containing accumulations of CGRP- and SP-positive vesicles, classical synaptic contacts were not present.

Autonomic pathways in the orbit of the human fetus and the rhesus monkey

In order to study the three-dimensional topography of the intra-orbital autonomic nerve plexuses and the input for these systems, human fetuses and adult rhesus monkeys were investigated. Specimens of the orbits were processed according to the histochemical acetylcholinesterase methods for staining of peripheral nerves. The nerve fibers enter the orbit along the following pathways: 1. bundles of nerve fibers from the pterygopalatine ganglion (mainly parasympathetic) by penetrating the orbital muscle (Müller); 2. perivascularly along the ophthalmic artery (sympathetic). In the orbit the nerve fibers intermingle. The pathways of the nerve fibers from this interwoven nerve plexus towards the target organs are: 1. perivascularly along branches of the ophthalmic artery; 2. perineurally along and in the branches of the ophthalmic and maxillary nerves; 3. independently of blood vessels and cranial nerve branches in Tenon's capsule. Moreover, bundles of nerve fibers from the ciliary ganglion contribute to the innervation of extraocular structures, e.g. the eyelids. It can be concluded that, as far as the autonomic innervation of the orbit is concerned, the monkey is a good animal model for neuroanatomical studies.

Congenital anomalies in the teratological collection of Museum Vrolik in Amsterdam, The Netherlands. IV: closure defects of the neural tube

The Museum Vrolik collection of the Department of Anatomy and Embryology of the University of Amsterdam, founded by Gerardus Vrolik (1775-1859) and his son Willem Vrolik (1801-1863), consists of more than 5,000 specimens of human and animal anatomy, embryology, pathology, and congenital anomalies. Recently, the collection of congenital anomalies, comprising 360 specimens, was recatalogued and redescribed according to contemporary morphogenetic opinions. The original descriptions, as far as preserved, were compared with the clinical and additional findings. Based on the classification by closure site, proposed by Van Allen et al. [1993], the following closure defects of the neural tube were diagnosed in 107 specimens: craniorachischisis, holoacranium with partial rachischisis, faciocranioschisis, holoacranium, meroacranium, occipital cranioschisis, frontal encephalocele, parietal encephalocele, occipital encephalocele, occipital encephalocele with rachischisis, occipito-cervical encephalocele, thoracolumbar spina bifida, lumbosacral spina bifida, occult sacral dysraphism, and sacrococcygeal dysgenesis. Furthermore, we diagnosed three conditions that did not appear in the aforementioned classification; we named these conditions craniorachischisis totalis, occipital craniorachischisis, and thoracolumbosacral spina bifida. The results of our study are in line with the assumption that particularly occipito-cervical neural tube defects are associated with concomitant anomalies and are more common in females. The results support the idea of multisite closure of the human neural tube.

Processed porcine collagen tubulization versus conventional suturing in peripheral nerve reconstruction: An experimental study in rabbits

In peripheral nerve reconstruction, various procedures are used. One of the procedures that received the most interest in the past decade is the tubulization technique for small nerve gaps. A disadvantage in the use of non-biodegradable tubes is that the material often has to be removed owing to its mechanical properties. Some investigators, in exploring the use of collagen tubes, being a natural biodegradable material, found either allogenicity or xenogenicity and immune responses that may inhibit nerve regeneration. Processed porcine collagen (PPC) is a new inert and biodegradable material that has a favorable effect on wound healing, as demonstrated by experiments on other tissues. The aim of our study was to compare the healing of nerve sutures with PPC tubes with conventional end-to-end sutures. In our experiments, we reconstructed the saphenous nerves of 27 rabbits. In series 1 (n = 12) and 2 (n = 12), PPC tubes were slid over an end-to-end nerve suture without or with a 10-mm nerve gap, respectively. In series 3 (n = 12), conventional suturing was performed in the collateral saphenous nerves of the animals of series 1. Epineurial suturing was performed. Three other non-operated saphenous nerves served as controls. The healing was studied after 3, 6, and 12 months in sections stained by monoclonal antibodies and by conventional histologic staining. Morphometric analysis of the regenerating axons was done by using confocal scanning laser microscopy (CLSM). Data analysis was carried out using a software program especially developed for this purpose. All results were evaluated statistically. Our results showed that during the healing period in the distal nerve stump, the number of axons of the PPC procedure with a 10-mm gap was significantly higher than that in the procedure without a gap. At 12 months, the mean number of axons of all procedures was significantly lower than in the non-operated nerve, and the mean axon diameter in all distal stumps did not differ significantly from that of the non-operated nerve. In the distal nerve stump, the ratio of total axon area to total fascicle area in the PPC procedure with a gap was significantly higher than that in the conventional suturing procedure. After 12 months, there was no significant difference between the percentages of axon outgrowth of the PPC procedure without a gap, the conventional suturing procedure, and the non-operated nerve (100%). The percentage of axon outgrowth in PPC with a gap was significantly higher than in the other procedures.

A 100-year-old anatomical specimen presenting with boomerang-like skeletal dysplasia: diagnostic strategies and outcome

The Museum Vrolik collection of human anatomy comprises 360 recently redescribed specimens with congenital anomalies. The specimen described here dated from 1881 and presented with a general embryonic appearance, disproportionate short stature, brachycephaly, widened cranial sutures, hypertelorism, microphthalmia, bilateral cleft lip and palate, micrognathia, short and curved limbs, polysyndactyly, and abnormal female genitalia. Conventional radiography was hampered by decalcification of the skeleton, due to acidification of the preservation fluid. The use of additional imaging techniques, i.e., mammography, computerized tomography with three-dimensional reconstruction, and magnetic resonance imaging eventually led us to conclude that the condition of our specimen was similar to Piepkorn type skeletal dysplasia, boomerang dysplasia, and a condition described by Carpenter and Hunter [1982: J Med Genet 19:311-315], though none of these diagnoses seemed fully applicable.

The painted Amsterdam anatomy lessons: anatomy performances in dissecting rooms?

The Anatomy Lesson of Dr. Nicolaes Tulp, painted by Rembrandt in 1632, has recently been fully restored. From 02-10-98 to 10-01-99 this painting and some other Amsterdam painted anatomy lessons were exhibited in the Mauritshuis in The Hague, with the title "Rembrandt under the scalpel". The unique Tulp painting is one of those portraits painted in the tradition of the famous group portraits which flourished in 17th-century Holland, a predominantly urban, middle-class society where the main patrons of the arts were the leading citizens of the various towns. Moreover, it is a portrait in the tradition of the anatomy lessons especially painted for the Guild of Surgeons for their Guild Room. Nine such lessons have been painted for the guild and are still to be found in Dutch museums (Mauritshuis and Amsterdam Historical Museum). The anatomy lesson of Prof. Andreas Bonn, dated 1792, as well as some group portraits of the leading persons of the guild also play an important role in the Amsterdam group portraits. In 1925 the Amsterdam anatomist Louis Bolk commissioned Martin Monnickendam to paint another anatomy lesson. The restoration of the painting of Dr. Tulp has provided new information concerning the original composition of Rembrandt and the later additions. However, from an anatomical point of view, it is doubtful whether the Amsterdam anatomy lessons depict a real contemporary anatomical demonstration. They provide, together with archival sources, reliable information about the praelectores anatomiae and the leading persons of the guild, but fail to give much information about the dissecting room, the anatomy theatre or the procedure. The anatomical demonstration procedures of the guild are discussed in relation to the painted anatomy lessons.

Method for morphometric analysis of axons in experimental peripheral nerve reconstruction

A new method for morphometric analysis of axons in experimental peripheral nerve reconstruction is presented. Twelve adult female rabbits were used. In nine animals the saphenous nerve was transected and stitched epineurially. Three animals functioned as control. After 3, 6, and 12 months, the nerves were harvested, fixed in Kryofix and embedded in Histowax. Transverse sections of 6 microm were cut, immunohistochemically stained for NF 90, and counterstained by Sirius Red. Quantification of nerve fibers in cross sections was performed by using a confocal laser scanning microscope (CLSM), and the images were stored digitally. Data analyzing was performed by the Optimas program (5.2). Calculations were done with Microsoft Excel. The total number of axons, the mean axon diameter and the percentage axon area/fascicle area were evaluated statistically. This method for morphologic analysis provides automatically complete registration of axons and so different methods of experimental nerve reconstruction can be compared in a fast and reliable way.

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.

Pigment-containing cells in extraocular tissues of the primate

In the present study pigment-containing (PC) cells, localized in extraocular tissues of man and the cynomolgus monkey, were investigated to establish their localization, nature and relationships with the autonomic nervous system. In the orbit of man as well as the cynomolgus monkey three localizations of PC cells were detected: (1) Tenon's capsule along the ciliary arteries at the level of the entrance of the arteries into the eyeball, (2) Tenon's capsule along the ciliary nerves at the level of the entrance into the eyeball, and (3) the sclera around the ciliary arteries and nerves. Moreover in the orbit of the cynomolgus monkey PC cells were found along and around the accessory lateral rectus muscle. Histological, histochemical and electron microscopical studies led to the conclusions that PC cells are similar in nature to melanocytes and do not have neuronal properties. In contrast to the melanocytes in the anterior segment of the eye in both man and monkey, melanocytes in the extraocular tissues are not innervated either adrenergically or cholinergically.

Willem Vrolik on cyclopia

One of the founders of the Museum Vrolikianum, Professor Willem Vrolik (1801-1862), was very interested in teratology, especially in a congenital malformation termed cyclopia. In 1834 he published a paper on cyclopia. This work was mainly based on studies of cyclopic specimens present in the collection of his father, Professor Gerardus Vrolik. In this study he proposed a classification system for cyclopes, in which he divided them into five main types. This study also formed the basis for the chapters on cyclopia in his Handbook of pathological anatomy (1842-1844) and his Tabulae ad illustrandam embryogenesin hominis et mammalium (1844-1849). In these studies the specimens of cyclopes of man and mammals, still present in the collection of the Museum Vrolik in the Department of Anatomy and Embryology of the University of Amsterdam, were described and illustrated with beautiful lithographs. The collection consists of five human cyclopes and nineteen other cyclopic mammals. These mammals are pigs, lambs and a cat.