The yield of synaptosomes from the cerebral cortex of guinea pigs estimated by a polystyrene bead “tagging” procedure

Summary The number of synaptosomes (pinched-off nerve endings) produced/g guinea pig cortex on homogenizing this tissue under defined conditions is estimated to be in the region of 4×10¹¹ using two different polystyrene bead tagging procedures. This is the same order of magnitude as the number of nerve endings/g cortex calculated from histological estimates given in the literature of the number of neurones in the cortex and the extent of their cortical connexions.This investigation was supported by U.S. Public Health Service Grant no. NB 03928 from the National Institute of Neurological Diseases and Blindness. Dr. Sheridan was a Postdoctoral fellow of the U.S. Public Health Service during the period of his participation in this investigation (1963/64). The electron microscope facilities were provided by the Wellcome Trust. Mr. T.F.J. Hobson, of the ARC Statistics group, Cambridge, kindly advised on statistical aspects of the work. We are most grateful to him, to Miss L. Swales and Mr. G.H.C. Dowe for their skilled technical assistance and to Dr. E.G. Gray for helpful discussions.     

The fine structure of photoreceptors in a marine flatworm

Summary The ocelli or eyes of the marine polyclad turbellarian Notoplana acticola are clustered on the paired dorsal nuchal tentacles and in two longitudinal bands lateral to the cerebral ganglion. The ocelli, studied by electron microscopy, were characterized as rhabdomeric and non-ciliary in origin. There are 60 to 80 ocelli per animal each enclosed in a fibrous capsule to which muscle fibers may attach. An ocellus consists of a pigmented eyecup into which 30 to 50 photoreceptor cells send dendritic processes through interruptions in or among pigment cell projections across the eyecup opening. The dendritic processes terminate in numerous long intertwined microvilli which fill the eyecup. The nucleated cell body of each photoreceptor cell lies outside the eyecup and projects an axonal process to the cerebral mass. Within the dendritic processes are observed mitochondria, ribosomes, neurotubules, multivesicular bodies, vesicles and vacuoles. The cell body contains smaller mitochondria, endoplasmic reticulum, ribosomes, vesicles and prominent Golgi complexes.After dark adaptation, there are some structural alterations in terms of swelling of microvilli, increased numbers of vacuoles associated with the microvilli and dendritic processes, and changes in the pigment cell projections.This work was supported by Grant No. GM 10292 from the U.S. Public Health Service to Professor Richard M. Eakin, Department of Zoology at the University of California, Berkeley, U.S.A., where this investigation was conducted during the author's sabbatical leave of absence from the University of Illinois, and by Grant No. 1 SO 1 FR 5369 from the U.S. Public Health Service to the University of Illinois at the Medical Center.I express appreciation to Professor Eakin for interesting discussions and generous hospitality to me as a guest in his laboratory, and to the John Simon Guggenheim Memorial Foundation for the Fellowship which I held during 1964–65. I thank Dr. John P. Marbarger, Director of the Aeromedical Laboratory for the electron microscope facilities used at the University of Illinois.     

Intranuclear annulate lamellae in oocytes of the tunicate,Styela partita

Summary Intranuclear annulate lamellae have been observed with the electron microscope in oocytes of the tunicate, Styela partita. Morphological evidence suggests that the annulate lamellae may arise by a specialized fusion process of individual vesicles. Intranuclear vesicles appear to be formed, in time, before differentiated annulate lamellae. It is also suggested that the position and structure of an annulus is in large part determined by the fusion of the vesicles. An annulus may be present as soon as two vesicles have completed their fusion process. Finally, it is again suggested on the basis of morphological evidence that the intranuclear vesicles are derived by the blebbing activity of the inner layer of the nuclear envelope.This investigation was supported by grants (RG-9229, 9230) from the National Institutes of Health, Public Health Service. The electron microscope facilities used were also supported by a grant (GM-05479) from the National Institutes of Health to Professor H. W. Beams.     

Further studies on polyploid amphibians (Ceratophrydidawe)

Odontophrynus cultripes Reinhardt and Lutken, 1862 has 22 chromosomes in its diploid complement. Spermatocyte I contained 11 ring bivalents and metaphase II exhibited 11 chromosomes. Odontophrynus americanus (Duméril and Bibron) 1882 has 44 chromosomes in somatic as well as germ cells, these can be sorted into 11 groups of homologues. Metaphase I showed varying numbers of quadrivalents and metaphase II exhibited 22 dyads. Ceratophrys dorsata Wied., 1824 has 104 chromosomes in somatic and germ cells; these 104 chromosomes comprise 8 each of 13 kinds of homologues. The spermatocyte I contained ring octovalents and other multivalents, and metaphase II 52 chromosomes. The above findings indicate that evolution by polyploidization occurred in South American frogs belonging to the family Ceratophrydidae.This work was supported by a grant (GM-14577-01) from the National Institute of General Medical Sciences U. S. Public Health Service.     

The reorganization of the hypophysial stalk following hypophysectomy in the teleost Porichthys notatus Girard

Summary Porichthys notatus has a long infundibular stalk, measuring 3 to 5 mm. The third ventricle extends into the stalk as a long infundibular funnel.In several hypophysectomised specimens the proximal cut end of the stalk enlarged to form a round or oblong body, having axonal endings with AF-positive material, glial elements, and blood sinuses. This suggests that in the absence of the pituitary the cut end of the stalk is reorganised into a neurohypophysis-like organ.The regenerated stalk seems to have the essential components for neurohypophysial function; axonal endings for the storage of secretory products, and related blood vessels for the release of the stored principles.This work was supported by the Population Council of the Rockefeller Institute, New York. I am thankful to Dr. R. L. Fernald, Director of the Friday Harbor Marine Biological Laboratories, University of Washington, for providing collection and laboratory facilities. I am indebted to Dr. Aubrey Gorbman, Department of Zoology, University of Washington for the generous hospitality in his laboratory and encouragement, which made this work possible. Material support in part for this research was received from U. S. P. H. S. grant NB 04887 awarded to Dr. A. Gorbman.     

Mitochondrion-desmosome complexes in human hepatocytes

Summary Mitochondrion-desmosome complexes similar to those seen in other epithelia were observed in hepatocytes from normal and diseased human livers of children and adults. Their occurrence could not be explained by random distribution of mitochondria in the cells. The close associations of mitochondria with desmosomes supported the hypothesis that the latter might be special areas of intercellular ionic diffusion between hepatocytes.This work was supported in part by United States Public Health Service Grants AI-1059 and TI AM-5384 from the National Institute of Arthritis and Metabolic Diseases, 5 MOl FR 000-50 from the General Clinical Research Center, HD 00674 from the National Institute of Child Health and Development and by a grant from the Life Insurance Medical Research Fund G-65-50.The author is very grateful to Dr. Alex B. Novikoff for the use of the facilities of his laboratory (supported by United States Public Health Service Grant CA-06576), to Mr. Nelson Quintana and Mrs. Julie Windsor for their superb technical assistance and to Miss Marianne Van Hooren for preparation of the photographs.     

Fluorescence microscopic observations of catecholamines in cultures of the sympathetic chains

Summary A histochemical technique for the demonstration of catecholamines developed by Falck et al. has been successfully applied to the sympathetic chains of rats and mice maintained in vitro. Catecholamines were localized in the nerve fibers, showing identical green fluorescence as in tissue sections of healthy rats. The cultures 8 days in vitro exhibited positive reaction in a few terminals, whereas sister cultures 1 month in vitro showed strong fluorescence reaction in thicker proximal axons and networks of nerve fibers as well. Reactivity of neuron somas became positive after 1 month of cultivation. Application of reserpine in amount of 0.00025 mg/ml for 2 hours resulted in complete disappearance of fluorescence. Furthermore, cultures of spinal ganglia from fetal rat produced no fluorescence reaction with this technique. Therefore, the reaction is specific for sympathetic nervous tissue and reliable for the differentiation of sympathetic neurons from other types of nerve cells.This work was supported by research grant NBO 3173 from the National Institute of Neurological Diseases and Blindness, U.S. Public Health Service, and research grant No. 355 from the National Multiple Sclerosis Society, New York.     

Tinea corporis caused by trichophyton mentagrophytes var. Granulosum

Summary A small outbreak of human ringworm caused byTrichophyton mentagrophytes var.granulosum is described. The clinical morphology of some of the inflammatory lesions was more suggestive of nummular eczema or psoriasis than of tinea corporis. The isolation of a granular strain ofTrichophyton mentagrophytes indicated an animal source of these infections. The same organism was isolated from a pet white rat which apparently transmitted the disease.These investigations were supported by a grant from the John. A. Hartford Foundation, Inc., New York, New York and the U.S. Public Health Service Training Grant No. 2A-5289.We wish to thank DoctorErnest Oehl of Philadelphia for referring these patients to the Skin and Cancer Hospital of Philadelphia.     

Histology and ultrastructure of the neural lobe of the lizard,Klauberina riversiana

Summary The pars nervosa of Klauberina riversiana belongs to a primitive tetrapod type which is characterized by the deep penetration of the infundibular recess, a thin-walled structure, and the virtual absence of pituicytes. The differential response of this gland to aldehyde fuchsin and periodic acid Schiff suggests the presence of two types of neurosecretory nerve endings. Ultrastructurally four kinds of nerve endings are distinguishable. Type I, probably a cholinergic nerve ending, contains only small clear vesicles ca. 400 Å in diameter. The relative abundance of cholinergic nerve endings in this pars nervosa may be related to the necessity of transporting hormone through the ependymal cell. Type II, containing granulated vesicles about 1,000 Å in diameter and probably aminergic, is very rare. The two remaining types apparently secrete neurohypophysial hormones. They are Type III, containing dense granules ca. 1,500 Å in diameter and Type IV containing pale granules ca. 1,500 Å in diameter. Evidence is reviewed which suggests that Type III nerve endings may secrete arginine vasotocin while Type IV endings may secrete (an)other hormone(s).All these axons end only on the ependymal cells, the vascular processes of which form a continuous cuff over the basement membranes of the blood vessels. Hence the ependymal cells link the cerebrospinal fluid, the nerve endings and the blood vessels. Particles resolvable with the electron microscope are traced through a possible transport pathway from the granules, through the ependymal cells to the basement membrane. It is suggested that pituicytes replace ependymal cells and assume their transport functions in animals with massive neural lobes containing large numbers of nerve endings and blood vessels.Fellow of the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina.This investigation was supported in part by a Public Health Service fellowship 1 FZ HD 32,949-01 REP from the national Institute of Child Health and Human Development.The authors wish to thank Professor H. Heller for his constant interest and constructive criticism.     

Ultrastructural study on the morphogenesis of the neuromuscular junction in the skeletal muscle of the chick

Summary The morphogenesis of the neuromuscular junction was examined at the ultrastructural level in the skeletal muscle of the lower limb of the chick. The fine structure of the neuromuscular junction of the adult fowl was essentially the same as that in other vertebrates; the junction consists of the axon terminal, the Schwann cell, and the muscle fiber. The first visible sign of neuromuscular junction formation, in embryos of 13 days in ovo, was the membrane thickening of the sarcolemma which develops into the postsynaptic membrane. The axons approaching the muscle fibers were incompletely ensheathed by a Schwann cell and contained vesicles. The subsequent differentiation of the junctional sarcoplasm, the axoplasm, and the Schwann cell cytoplasm takes place from 13 to 18 days in ovo and the junction nearly reaches maturity at around 20 days in ovo. The formation of complicated anastomoses and branching of the junctional infoldings seems to occur after hatching. These ultrastructural observations are in good agreement with histochemical findings (cholinesterase method) in terms of the chronology of the morphogenesis of the junction.This investigation was supported in part by U. S. Public Health Service Grant MH 12269-01, administered by Dr. Kazuo Ogawa. It was initiated on the suggestion of Prof. J. Nakai, Department of Anatomy, Faculty of Medicine, Tokyo University, and a part of it was performed in his laboratory. The author is greatly indebted to Prof. K. Ogawa, Department of Anatomy, Kansai Medical School, for his guidance and encouragement, and to Dr. S. Igarashi, Department of Anatomy, Tokyo University, for some technical advice.     

Genetic variation in the carbonic anhydrase isozymes of macaque monkeys. I. The radioimmunosorbent assay

A radioimmunosorbent technique is described which is capable of independently detecting both isozymes of carbonic anhydrase, CA I and CA II, in concentrations as low as 1 ng/ml. The technique is used to quantitate the different electrophoretic variants of red cell CA I as well as levels of CA II in the pig-tailed macaque, Macaca nemestrina.Supported by U.S. Public Health Service research grant GM-15419.U.S. Public Health Service Predoctoral Trainee (GM-71-14).     

Cytologic and metabolic parameters of pineal inhibition by continuous light in the rat (Rattus norvegicus)

Summary Adult rats (Rattus norvegicus) were subjected to continuous light or control conditions (14 hours light/day) for six weeks or longer, and quantitative cytological and metabolic studies were made of the pineal organs. After 11 weeks of continuous light, the pineal parenchymal cell's largest nucleolar eosinophilic mass is significantly reduced in diameter, especially in the medulla of the organ. Evidence of metabolic inhibition includes reduction of pineal glycogen content, succinic dehydrogenase activity, and respiration in the absence of exogenous substrates. Pineal ATP content, P³²-phosphate uptake and 5-hydroxy indole acetic acid content did not appear to be affected. Pineal serotonin content and melatonin-forming activity in the continuously lighted animals were measured but could not be interpreted metabolically, due to the diurnal fluctuations of these in control animals. Results provided here and elsewhere suggest that pineal inhibition by continuous light involves primarily the citric acid cycle, the accumulation of metabolites and lipid, and the synthesis of protein.This investigation was supported by grant GM-05219 from the National Institutes of Health, U.S. Public Health Service.I am grateful to Mrs. Virginia Green Bowers, Mrs. Ann Richards, Mr. Peter Charles Baker and Mr. Jorge Antonio Alvarado for laboratory assistance, and to Dr. Richard Strohman and Mr. David Epel, for advice on the determination of ATP.     

Growth inhibition ofMicrococcus pyogenes by manganese and riboflavin

Summary Riboflavin, in the presence of manganese, inhibited the growth ofMicrococcus pyogenes var.aureus. The inhibitory action was shown to be dependent upon aerobiosis, and was characterized predominately as a prolongation of the lag phase. Increasing concentrations of either manaanese or riboflavin, in the presence of a constant quantity of the other, enhanced the inhibitory effect. Ultra-violet irradiation of riboflavin reduced its toxic capacity in proportion to the amount of riboflavin degraded. Riboflavin-5-phosphate was equally as inhibitory as riboflavin. Ferrous iron was capable of a non-stoichiometric antagonism at low concentrations of riboflavin and/or manganese. Suported, in part, by a research grant (E-605) from the National Institutes of Health, U.S. Public Health Service. A preliminary report has appeared (Ramsey andWilson, 1956).     

The fine structure of sensory receptor processes in the auricular epithelium of the planarian,Dugesia tigrina

Summary The marginal epithelium of the lateral auricles of the planarian, Dugesia tigrina, includes a cell type with surface cilia and microvilli, a basal nucleus, and dense cytoplasm containing secretory vacuoles, Golgi elements, mitochondria and ribosomes. Through channels within the epithelial cytoplasm, cellular processes, interpreted as extensions of neurosensory receptor cells located in the subepidermis, project to the surface. The receptor processes, containing microtubules, mitochondria, vesicles and an agranular tubular reticulum, project beyond the epithelial cell surface; one or two cilia each emerge from a basal body in the apex of the projection. Close to the point of emergence to the epithelial surface, each cylindrical receptor process is surrounded by a collar-like septate junction between adjacent plasma membranes. The cilia of the projections differ from those of the epithelial cells in diameter, density of matrix and in the banding patterns of the rootlets. A few projections appear with the apex and basal body retracted below the epithelial surface. The possible function of these ciliated processes in sensory reception is discussed.This work was supported by Grant No. SO 1 FR 5369 from the U.S. Public Health Service to the University of Illinois at the Medical Center.I thank Dr. J. P. Marbarger, Director of the Research Resources Laboratory, for use of the electron microscope facilities, Miss Irena Kairys for technical help, Miss Marie Jaeger for assistance with photography, and Mr. Robert Parshall for the drawing.To Professor Arthur Wagg Pollister, I respectfully dedicate this article on the occasion of his retirement from Columbia University.     

Transition from polyteny to polyploidy in salivary glands of Cecidomyiidae

Summary Quantitiative cytochemical studies of Rana catesbeiana liver cell nuclei indicated that these populations consist entirely of diploid non-proliferating nuclei. While DNA values were stable, nuclear size varied over a considerable range. These size variations were directly related to total nuclear protein content, but protein SH and S-S content appeared to be related to ploidy rather than volume. Protein bound tyrosine represents an intermediate case. The latter two fractions appear to be partially bound to nucleic acids, since removal of either class of nucleic acid leads to an increase in absorption values.This investigation was supported by a grant from the U.S. Public Health Service, GM-10003-03.Post-Doctoral Trainee under U.S. Public Health Training Grant to the Department of Pathology, University of Florida, 5 Tl GM 1142-03.Supported by a Career Development award from the National Institute of Child Health and Human Development, K 3-HD-6176-03.     

Duplication of the autosomally inherited 6-phosphogluconate dehydrogenase gene locus in tetraploid species of cyprinid fish

Among members of the fish family Cyprinidae,a diploid—tetraploid relationship exists. The present study on electrophoretic patterns of 6-phosphogluconate dehydrogenase indicates that such diploid members as Barbus tetrazonamaintain allelic polymorphism at a single gene locus for this enzyme. Tetraploid members such as the carp and goldfish are endowed with two separate gene loci for 6-PGD. Tetraploid evolution apparently fixed two former alleles of the same locus as two separate gene loci. Furthermore, it appears that after becoming tetraploid, the carp and goldfish developed a separate regulatory mechanism for each locus; thus preferential activation of one or the other 6-PGD locus occurs in different tissues of tetraploid species. This investigation was supported in part by a grant (CA-05138) from the National Cancer Institute, U.S. Public Health Service, and in part by a research fund established in honor of General James H. Doolittle. Contribution No. 4-68, Department of Biology, City of Hope Medical Center.Dr. Bender is a recipient of International Postdoctoral Fellowship 3 F05-TW-01198-0152 from the U.S. Public Health Service.     

Karyometric and cytophotometric study of hepatocyte nuclei of frogs exposed to cold and prolonged starvation

Summary Prolonged starvation of Rana pipiens at room temperature results in a decrease in the volume of the hepatocyte nuclei from that of recently fed individuals. A converse increase in the volume of the liver nuclei over the normal was noted in frogs exposed to low temperature for 10 days. The present work was conducted in an effort to determine which nuclear fraction is responsible for the observed changes in nuclear size.The amount of DNA, RNA and protein-bound sulfhydryl groups per nucleus was measured cytophotometrically and was found to be independent of changes in nuclear size. Total nuclear protein content, on the other hand, was found to vary in proportion to nuclear volume. It was concluded that the variation in nuclear size resulting from starvation and cold-treatment is due to differences in non-chromosomal protein content and cannot be attributed to changes in ploidy.Dedicated to Prof. Berta Scharrer in honor of her 60th Birthday. — Supported by U.S. Public Health Service Grant HD-1499-04 to Dr. Cowden.Work completed while a Postdoctoral Trainee under U.S. Public Health Training Grant to the Department of Pathology, University of Florida, NIH-GM-1142-03.Supported by a Career Development Award from the National Institute of Child Health and Human Development, K 3-HD-6176-04.     

On the cilium cell relationship in the adenohypophysis of the mouse

Summary The 8+1 cilia previously reported in the adenohypophysis have been reinvestigated with special emphasis on their relation to the parent cell. In contrast to the fibril pattern which is remarkably constant, this relation shows great variation, supporting the hypothesis that the cilia are rudimentary.This study was supported in part by Grant NB 02215 of The National Institute of Neurological Diseases and Blindness, U. S. Public Health Service. This aid is gratefully acknowledged. The author wishes to thank Dr. Th. Blackstad for valuable advices and Mrs. J. L. Vaaland for skillful technical assistance.     

Diploid-tetraploid relationship among old-world members of the fish family Cyprinidae

Evidence suggesting that the goldfish and the carp of the family Cyprinidae are tetraploid species in relation to other members of the same family were presented. The two barb species, Barbus tetrazona and Barbus jasciatus, were chosen as representatives of diploid members of the family Cyprinidae. These barbs had the diploid chromosome number of 50 and 52 and the DNA value 20–22% that of placental mammals, while the goldfish (Carassius auratus) and the carp (Cyprinus carpio) had the diploid chromosome number of about 104 and the DNA value 50–52% that of placental mammals.Supported in part by a grant (CA-05138) from the National Cancer Institute, U.S.Public Health Service, and in part by a research fund established in honor of General James H. Doolittle at Duarte, and by the British Empire Cancer Campaign for Research at Northwood. Contribution No. 11-67, Department of Biology, City of Hope Medical Center. Dr. Junichi Muramoto is a fellow of the Institute for Advanced Learning of the City of Hope Medical Center.     

Regionale Strukturunterschiede im Nucleus infundibularis der Vögel (Passeriformes)

Zusammenfassung Der Nucleus infundibularis einiger Vögel (Zonotrichia leucophrys gambelii, Carduelis chloris, Passer domesticus) läßt eine deutliche regionale Untergliederung erkennen. Bei der nordamerikanischen Weißhauptammer (Zonotrichia leucophrys gambelii) verdienen diese aus Ansammlungen kleiner oder großer Nervenzellen bestehenden Kernabschnitte eine besondere Beachtung im Hinblick auf die stereotaktischen Eingriffe am Hypothalamus (P. B. Wilson) und deren Auswirkungen auf die lichtabhängige Gonadenreaktion (D. S. Farner).

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Regional differences in the structure of the infundibular nucleus in birds (Passeriformes)

Summary In the infundibular nucleus of some avian species (Zonotrichia leucophrys gambelii, Carduelis chloris, Passer domesticus) several subdivisions are described. In the Whitecrowned Sparrow, Zonotrichia leucophrys gambelii, this arrangement of small and large nerve cells seems to be important with respect to studies on hypothalamic lesions (P. E. Wilson) and their effect on the photoperiodically induced gonadal growth (D. S. Farner).

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Herrn Prof. Dr. Dr. h.c. Hugo Spatz gewidmet.

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft. Herrn Prof. Dr. D.S. Farner, Department of Zoology, University of Washington, Seattle, U.S.A., danke ich für einen Teil des Hirnmaterials (Research grant 5R 01 NB 06187 from the National Institutes of Health to Professor D. S. Farner).