Histochemical observations on the giant neurosecretory cells of the thoracic ganglion of the adult and juvenile crabs, Potamon magnum magnum (Pretzman).

The giant neurosecretory cells in the thoracic ganglion of the adult and juvenile crab, Potamon magnum magnum (Pretzman) were histochemically investigated. The secretion is mainly proteinaceous in nature, containing considerable amounts of acid mucosubstances, sulphate esters, lipids and a little carbohydrate but no glycogen. The detailed nature of proteinaceous neurosecretory material in the adult crab was further tested. It appears that the neurosecretory material of these cells contains moderate amounts of sulfhydryl groups and few of disulphide bonds. No trace of tyrosine could be observed. The neurosecretory granules were associated with considerable amounts of cytoplasmic RNA. In general, stronger reactions were obtained in summer and winter than in other seasons.     

Further observations on the B-type neurosecretory cells in the thoracic ganglion of the crab, Potamon magnum magnum (Pretzman).

Only four types of the secretory neurones were observed in the thoracic ganglion of the fresh water crab, Potamon magnum magnum (Pretzman). These cells are classified as A, A', B and C types. Our results also confirmed that the B and B' types of cells (BAID et al. 1968) are one and the same type, the B cells. The B cells are of two forms, with and without the axons. They clearly showed sequential histological patterns pointing out to their phases. The secretory material is discharged either through the periphery or through the axon and periphery both. The vacuoles were observed in both the forms of the B cells. The remarkable sign of the activity of the nuclear membrane especially at the beginning of the secretory cycle and the appearance of the first secretory granules around the nucleus strongly support the vital role of the nucleus in the initiation of the secretory cycle.     

Foramen magnum position in bipedal mammals

The anterior position of the human foramen magnum is often explained as an adaptation for maintaining balance of the head atop the cervical vertebral column during bipedalism and the assumption of orthograde trunk postures. Accordingly, the relative placement of the foramen magnum on the basicranium has been used to infer bipedal locomotion and hominin status for a number of Mio-Pliocene fossil taxa. Nonetheless, previous studies have struggled to validate the functional link between foramen magnum position and bipedal locomotion. Here, we test the hypothesis that an anteriorly positioned foramen magnum is related to bipedalism through a comparison of basicranial anatomy between bipeds and quadrupeds from three mammalian clades: marsupials, rodents and primates. Additionally, we examine whether strepsirrhine primates that habitually assume orthograde trunk postures exhibit more anteriorly positioned foramina magna compared with non-orthograde strepsirrhines. Our comparative data reveal that bipedal marsupials and rodents have foramina magna that are more anteriorly located than those of quadrupedal close relatives. The foramen magnum is also situated more anteriorly in orthograde strepsirrhines than in pronograde or antipronograde strepsirrhines. Among the primates sampled, humans exhibit the most anteriorly positioned foramina magna. The results of this analysis support the utility of foramen magnum position as an indicator of bipedal locomotion in fossil hominins.     

Position and orientation of the foramen magnum in higher primates

The location of the foramen magnum, with respect to the longitudinal axis of the cranium, and its orientation with respect to the Frankfurt Horizontal, have been studied in a total of 328 modern human and Pan crania. The samples were chosen in order to examine the effect of overall size difference on foramen magnum disposition. Foramen position (expressed as three indices) and inclination are relatively invariant among the modern human samples, but the foramen magnum is consistently, and statistically significantly, more anteriorly located in Pan paniscus than in Pan troglodytes. Sexual dimorphism is virtually non-existent. There is an apparent allometric effect on foramen position, but not on inclination, so that larger crania in the modern human and Pan paniscus samples tend to have more posteriorly situated foramina. The disposition of the foramen is unrelated to cranial base angle or facial prognathism, except that in Pan paniscus its relative anterior location is linked with the more flexed cranial base in that species. These results provide a comparative context for the examination of differences in foramen magnum disposition in fossil hominids. Differences in foramen magnum position and orientation between KNM-ER 1813 and A. africanus are most unlikely to be due to within-taxon variability.     

大网柄菌Dictyostelium magnum生活史的研究

为了了解网柄菌生活史循环的整个过程,显微观察了大网柄菌Dictyostelium magnum在双凹载玻片及水琼脂培养基上的完整生长循环,记录了大网柄菌生活史中各阶段,即孢子、黏变形体、集群、假原质团、拔顶、孢堆果及再次释放孢子的显著特征,整个生活循环历时2－3d。     

Study of the anatomic metric values of the foramen magnum and its relation to sex

The sagittal and transverse diameters of the foramen magnum were examined in 100 human skulls (74 male, 26 female). The results were statistically analyzed and compared with those obtained by other authors. Our findings show that the sagittal and transverse diameters are clearly different, as well as the total area of the foramen magnum, these parameters being larger in male skulls than in female.     

大型多钩槽绦虫与隐藏新棘虫种间关系研究

大型多钩槽绦虫和隐藏新棘虫单独在黄鲜肠道内分布时,其分布益十分相似,相似性系数ｒ＝０．９２２６（Ｐ〈０．０１）,当两种寄生蠕虫在黄鳝中共同感染时,随着大型多钩槽绦虫的生长,其分布位置明显前移而隐藏新棘虫的分布位置则显著后退,生态２位重叠明显下降。两种寄生蠕虫种间正关联显著,它们在宿主人共存并不改变它们的感染速度。     

Changes in the presence of progesterone receptor isoforms in the oviduct magnum of newly-hatched chicks after gonadotropins treatment

The effects of Follicle-stimulating hormone (FSH) and Luteinizing hormone (LH) on progesterone receptor (PR) isoforms presence in different cell populations from the oviduct magnum of newly-hatched chicks treated in vivo on days 13, 15 and 17 of embryonic development, were analyzed by immunohistochemistry. We found that FSH promoted cytodifferentiation of the magnum's mucosa and increased PR immunoreactivity in all cell types of the oviduct magnum, whereas LH-treatment did not exert cytodifferentiation of magnum's mucosa, and PR immunoreactivity was only induced in some epithelial and stromal cells of the oviduct magnum. In all treatments the number of PR immunopositive cells incubated with the antibody PgR Ab-8 that recognizes both PR isoforms were significantly higher than the number of immunopositive cells incubated with antibody PgR Ab-6 that only recognizes PR-B. This suggests that PR-A should be the predominant isoform in the oviduct magnum of newly-hatched chicks treated with gonadotropins during embryonic development.We conclude that gonadotropins differentially regulate PR-A isoform presence in the oviduct magnum of newly-hatched chicks.     

Effects of age and gender on the location and orientation of the foramen magnum in rhesus macaques (Macaca mulatta)

Endocasts from 378 rhesus macaque skulls from the Cayo Santiago skeletal collection were measured to determine the effects of age and gender on the position and orientation of the foramen magnum. The foramen magnum migrates from a rostral to a caudal position and its angle changes during postnatal development. The angles and relative positions of the foramen magnum are similar for both genders of infants and for both genders of adults. However, analyses of linear response and plateau (LRP) functions reveal significant differences between males and females in the timing of reorientation of the angle and migration of the foramen magnum. The mean adult angle and relative position of the foramen magnum are reached by 4.7 years in females, but they do not achieve their adult values until 7.1 years in males. A similar pattern is observed for the brainstem region of the basicranium. Mean adult lengths of the brainstem region are reached at 5.2 years in females and 7.1 years in males. The relationships between cranial capacity, the growth pattern of the brainstem, and the pattern of change for the angle and the relative position of the foramen magnum are examined. Quantification of the effects of age and gender on the location of the foramen magnum in a large sample of endocasts from one species of higher primate has potential implications for research on human development, and for interpretation of juvenile specimens in the hominid fossil record.     

The implantation of puromycin into the neurosecretory nuclei of the rat

Summary Following the bilateral implantation of puromycin into the paraventricular nuclei of rats, the neurosecretory cells became atrophic and the amount of aldehyde-fuchsin (AF) positive material in the neural lobe decreased. In these rats, urine excretion and water intake increased remarkably. The supraoptic nuclei of the rats were not affected by this treatment. After the unilateral implantation of puromycin in the paraventricular nucleus, the neurosecretory cells of the implanted side became atrophic, while those of the unimplanted side hypertrophied. The neural lobe contained similar amounts of AF-positive material to those of the control rats with unilateral cholesterol implants. In the rats implanted bilaterally with puromycin immediately above the supraoptic nucleus, the neurosecretory cells of this nucleus contained little or no AF-positive material, and urine excretion and water intake increased greatly. The cells of the paraventricular nucleus remained unchanged in these rats.     

Cytophysiology of neurosecretory axon terminals in the brain of an annelid (Ophryotrocha puerilis,Polychaeta)

Summary In the posterior part of the brain of the protandric polychaete Ophryotrocha puerilis neurosecretory cells form prominent axon terminals. The terminals are arranged in two complexes. The perikarya of these presumably monopolar neurons are scattered in the anterior part of the cerebral perikaryal layer. In females the terminals store large amounts of neurosecretory material. It has been suggested earlier that neurosecretions of the terminals may play a role during sex reversal from females to males. Application of histamine caused the release of neurosecretory material from the respective terminals in females. However, this discharge was not followed by sex reversal. Application of reserpine had no influence on the terminals. Neither by in vivo observation nor by ultrastructural analysis any effect of reserpine on the terminal complexes could be observed. In isolated terminals filled with neurosecretory material from females, catecholamines could not be detected by HPLC. Also, polyclonal antibodies against dopamine did not stain the terminal complexes. Furthermore, the complexes did not develop any fluorescence after glyoxylic acid treatment. Therefore, the present results contradict the hypothesis that the neurosecretory material of the respective axon terminals is catecholaminergic and that it is involved in sex differentiation. The function of the secretory neurons studied here remains unclear.Abbreviations AT axon terminal - CA catecholamine(s) - DA dopamine - DAB diaminobenzidine - GA glyoxylic acid - GIF glyoxylic acid-induced fluorescence - LY Lucifer Yellow - MB methylene blue - NSM neurosecretory material - OTH ootropic hormone - TC terminal complex     

Genetic differences in steroid-induced protein synthesis in vivo of the liver and magnum in immature chicks (Gallus domesticus).

1. The present study was conducted to investigate whether or not the rate of steroid-induced protein synthesis measured in vivo in the liver and magnum was different between chicks from different genetic backgrounds. 2. Both protein deposition and synthesis in the liver were enhanced after the administration of beta-estradiol with or without testosterone. In the magnum, the combined administration of beta-estradiol and testosterone resulted in significantly higher protein deposition and synthesis than did beta-estradiol alone. 3. After the administration of beta-estradiol and testosterone, protein deposition in the liver and magnum was lower in broiler than in layer and dual-purpose chicks. Protein synthesis in the magnum tended to be highest, though not significantly, in layer, followed by dual-purpose and broiler chicks in decreasing order. 4. Steroid-induced protein deposition in the liver was not changed between chicks genetically selected for low and high albumen contents. In contrast, steroid-induced protein synthesis in the magnum was significantly higher in high-albumen birds than low-albumen chicks. 5. It was concluded that genetic traits for high egg production were well reflected in increased protein deposition and synthesis in the liver and especially in the magnum of immature female chicks stimulated by steroid hormone treatment.     

Changes in ovalbumin and protein synthesis in vivo in the magnum of laying hens during the egg formation cycle.

1. The present study was carried out to investigate whether or not the rate of synthesis of total protein in various oviducal segments and ovalbumin, a major egg white protein, in the magnum fluctuated during the egg formation cycle in laying hens. 2. Synthesis of total protein and ovalbumin was measured in vivo by the incorporation of [15N]methionine after a primed continuous infusion of tracer for 3 hr. 3. Protein and ovalbumin contents in the magnum and the entire oviduct decreased sharply when an ovum moved down from the magnum to the isthmus, probably due to the secretion of egg white proteins. 4. In contrast, total protein and ovalbumin synthesis in the magnum was significantly higher when an ovum was in there than when it was in any other segments. Fluctuations of ovalbumin synthesis and total protein synthesis in the magnum were roughly parallel to those of total protein synthesis in the entire oviduct. 5. It was concluded, therefore, that the changes seen in total protein synthesis in the whole oviduct during the egg formation cycle were mainly attributable to those in magnum protein synthesis, of which a significant portion was accounted for by the synthesis of ovalbumin.     

The effect of castration upon the ultrastructure of the rat hypothalamus

Summary The neurosecretory hypothalamic nuclei and the inner zone of the median eminence of castrated rats were studied under the electron microscope. After one month of castration all the neurosecretory neurons of both nuclei show signs of hyperactivity characterized by dilated cisternae of the endoplasmic reticulum containing a macromolecular filamentous material and an increase in the number of ribosomes. After six months of castration, some neurosecretory neurons show an increased number of neurotubules and larger lysosomes than in the controls. Other neurons show a very significant hypertrophy of the endoplasmic reticulum, with large amounts of intracisternal filamentous material. These cells have few neurosecretory granules and in the adjacent synapses the number of granulated vesicles is increased. In the supraoptic nucleus there are two kinds of neurosecretory axons: the clear ones, which are similar to those that appear in control animals and the dark ones, which have smaller elementary granules. In the inner zone of the median eminence the axons show an increase in the number of neurosecretory granules with respect to the controls. After supplementary administration of sexual hormones, all the modifications produced by castration disappear. The ultrastructural changes observed in the neurosecretory nuclei after castration are discussed in relation to those previously described in the neurohypophysis under the same experimental conditions. A feedback regulatory action of sex hormones on hypothalamic neurosecretory neurons is postulated.Supported by grants from the Consejo Nacional de Investigaciones Científicas y Técnicas and by the Air Force Office of Scientific Research (AF-AFOSR 963-67).We are deeply indebted to Mrs. Defilippi-Novoa and Mr. Alberto Saenz for their skillful assistence.     

Ultrastructure of the hypothalamic neurosecretory system of the dog

Summary The hypothalamic neurosecretory system of normal dogs was studied by light and electron microscopy after perfusion-fixation. In the supraoptic nucleus most neurons are loaded with elementary neurosecretory granules having a content of low electron density. Neurons with less neurosecretory material and signs of enhanced synthetic activity, as recognized by the changes in the endoplasmic reticulum, were also observed.The vesiculated neurons ofJewell were studied under the electron microscope and various stages of development were described. It was postulated that they originate by a localized process of cytoplasmic cytolysis which ends in the formation of a large aqueous intracellular cavity limited by a plasma membrane. The possible significance of these vesiculated neurones is discussed. Some few myelinated neurosecretory axons are found in the supraoptic nucleus.The neurons of the paraventricular nucleus are smaller and contain less neurosecretory material. This is abundant and very pale in the axons. The median eminence consists of an inner zone, mainly occupied by the neurosecretory axons of the hypothalamic-neurohypophysial tracts, and an outer zone in which some neurosecretory axons end on the capillary of the portal system. This outer zone contains numerous axons with the axoplasm rich in neurofilaments and some containing granulated and non-granulated synaptic vesicles. Some neurons with granulated vesicles were observed in this region. The adrenergic nature of these neurons and axons is postulated.The infundibular process of the neurohypophysis shows small axons with discrete amounts of elementary granules and vesicles of synaptic type at the endings. Some enlarged axons having, in addition, large polymorphic bodies are observed and related to the Herring bodies.The size and morphology of the granules are analyzed along the entire hypothalamic-neurohypophysial system. The changes in diameter and electron density are related to the maturation of the granules and the possible significance of such evolution.Supported by grants from the Consejo Nacional de Investigaciones Cientificas y Técnicas and by the Air Force Office of Scientific Research (AF-AFOSR 963-66).     

Neurosecretory and microstructural changes in the hypothalamus of rats following administration of lithium chloride and 3H-thymidin

Adult male rats were intraperitoneally administered aqueous solution of lithium chloride (LiCl). Studies, including neurosecretory and microstructural changes within particular neurocytes in supraoptic (NSO) and paraventricular nuclei (NPV) were performed on hypothalamic sections. In the experimental rats the administered LiCl increased the level of GOMORI-positive neurosecretory material both in supraoptic and paraventricular nuclei. Great amounts of the neurosecretory material were markedly conspicuous in the above areas after 20 days of LiCl administration. Investigations carried out on cellular nuclei of particular neurocytes showed a significant enlargement of the nuclei, and statistical calculations revealed that, in comparison with the basic control, the difference was essentially significant (p less than 0.001). 3H-thymidin administration to the rats which had previously been on LiCl for 20 days demonstrated also that within supraoptic nuclei the incorporation of the isotope in cellular nuclei took a faster course than in control animals.     

Fermeture des synchondroses intra-occipitales : implication dans la configuration du foramen magnum

When dental remains are not available, estimation of age at death of children depends on the state of maturation of the skeleton, in particular for fossil children. In this study, age of fusion of anterior and posterior intra-occipital synchondroses (respectively SIOA and SIOP) and foramen magnum shape, related with synchondroses fusion, are studied on a sample of known age and sex. Reliability of these two synchondroses as indicators of the age at death of children as well as the phylogenetic value of foramen magnum shape is discussed. To cite this article: H. Coqueugniot, J.-M. Le Minor, C. R. Palevol 1 (2002) 35–42.     

Färberische Beobachtungen zur Frage nach dem primären Bildungsort von Neurosekret im supraoptico-hypophysären System

Zusammenfassung An Embryonen und Jungtieren von Maus und Huhn wurde die Entwicklung des neurosekretorischen hypothalamo-hypophysären Systems untersucht. Dabei gelang es, neurosekretorisches Material in den Perikaryen des Systems zum gleichen Zeitpunkt nachzuweisen, zu dem es in der Neurohypophyse erstmalig auftrat.In vergleichend-anatomischen Untersuchungen an erwachsenen Tieren ließ sich bei einer Reihe von Säugetierarten Neurosekret im Verlauf des gesamten Neurons sichtbar machen. Korrespondierende Neuronabschnitte verschiedener Spezies enthielten dabei vergleichbare Neurosekretmengen.Die Befunde wurden mit verbesserten Verfahren zur färberischen Darstellung von Neurosekret gewonnen. Die von ihnen abweichenden Ergebnisse früherer Untersuchungen beruhen auf unzulänglichen Methoden und können daher nicht gegen die Hypothese eines intraaxonalen Neurosekret-Transportes ins Feld geführt werden.

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Stainability of neurosecretory material and the beginning of its formation in the supraoptico-hypophysial system

Summary The development of the neurosecretory hypothalamo-hypophyseal system of mouse and chick embryos has been studied. Neurosecretory granules could be identified in the perikarya of the neurosecretory cells simultaneously with their first appearance in the neurohypophysis.Subsequently, a variety of adult mammalian species was investigated. In all cases, neurosecretory material could be demonstrated along the whole length of the neurons. Comparison of corresponding parts of the neurons showed them to contain comparable amounts of neurosecretory material.The investigations were carried out with improved techniques for staining neurosecretory material. Results of earlier investigations, inconsistent with these findings, were obtained with inadequate methods and cannot be regarded as contradicting the hypothesis of an intraaxonal transport of neurosecretory material.

     

A method for making an endocranial cast through the foramen magnum of an intact skull

It is possible to make an endocranial cast through the foramen magnum of an intact skull by using several layers of liquid latex. The technique described here includes the preparation of the skull; the method of pouring and curing the layers of liquid latex; the loosening and removal of the latex cast; and lastly making the final endocranial cast.     

Biochemical and molecular characterization of the Clostridium magnum acetoin dehydrogenase enzyme system.

E2 (dihydrolipoamide acetyltransferase) and E3 (dihydrolipoamide dehydrogenase) of the Clostridium magnum acetoin dehydrogenase enzyme system were copurified in a three-step procedure from acetoin-grown cells. The denatured E2-E3 preparation comprised two polypeptides with M(r)s of 49,000 and 67,000, respectively. Microsequencing of both proteins revealed identical amino acid sequences. By use of oligonucleotide probes based on the N-terminal sequences of the alpha and beta subunits of E1 (acetoin dehydrogenase, thymine PPi dependent), which were purified recently (H. Lorenzl, F.B. Oppermann, B. Schmidt, and A. Steinbüchel, Antonie van Leeuwenhoek 63:219-225, 1993), and of E2-E3, structural genes acoA (encoding E1 alpha), acoB (encoding E1 beta), acoC (encoding E2), and acoL (encoding E3) were identified on a single ClaI restriction fragment and expressed in Escherichia coli. The nucleotide sequences of acoA (978 bp), acoB (999 bp), acoC (1,332 bp), and acoL (1,734 bp), as well as those of acoX (996 bp) and acoR (1,956 bp), were determined. The amino acid sequences deduced from acoA, acoB, acoC, and acoL for E1 alpha (M(r), 35,532), E1 beta (M(r), 35,541), E2 (M(r), 48,149), and E3 (M(r), 61,255) exhibited striking similarities to the amino acid sequences of the corresponding components of the Pelobacter carbinolicus acetoin dehydrogenase enzyme system and the Alcaligenes eutrophus acetoin-cleaving system, respectively. Significant homologies to the enzyme components of various 2-oxo acid dehydrogenase complexes were also found, indicating a close relationship between the two enzyme systems. As a result of the partial repetition of the 5' coding region of acoC into the corresponding part of acoL, the E3 component of the C. magnum acetoin dehydrogenase enzyme system contains an N-terminal lipoyl domain, which is unique among dihydrolipoamide dehydrogenases. We found strong similarities between the AcoR and AcoX sequences and the A. eutrophus acoR gene product, which is a regulatory protein required for expression of the A. eutrophus aco genes, and the A. eutrophus acoX gene product, which has an unknown function, respectively. The aco genes of C. magnum are probably organized in one single operon (acoABXCL); acoR maps upstream of this operon.