Neocortical transplants in the rat brain: an ultrastructural study

Electron microscopic analysis of neocortical transplants in the cerebellum of the host animals showed that the nerve cells, glial cells, and neuropil of the transplants were normal. These transplants showed anatomical integration with the host brain through various regions of interface. Neuropil interfaces were found to have a high density of synaptic profiles, and medullary interfaces had a very small number of synaptic profiles.     

Human embryonic stem cell-derived neurons establish region-specific, long-range projections in the adult brain

While the availability of pluripotent stem cells has opened new prospects for generating neural donor cells for nervous system repair, their capability to integrate with adult brain tissue in a structurally relevant way is still largely unresolved. We addressed the potential of human embryonic stem cell-derived long-term self-renewing neuroepithelial stem cells (lt-NES cells) to establish axonal projections after transplantation into the adult rodent brain. Transgenic and species-specific markers were used to trace the innervation pattern established by transplants in the hippocampus and motor cortex. In vitro, lt-NES cells formed a complex axonal network within several weeks after the initiation of differentiation and expressed a composition of surface receptors known to be instrumental in axonal growth and pathfinding. In vivo, these donor cells adopted projection patterns closely mimicking endogenous projections in two different regions of the adult rodent brain. Hippocampal grafts placed in the dentate gyrus projected to both the ipsilateral and contralateral pyramidal cell layers, while axons of donor neurons placed in the motor cortex extended via the external and internal capsule into the cervical spinal cord and via the corpus callosum into the contralateral cortex. Interestingly, acquisition of these region-specific projection profiles was not correlated with the adoption of a regional phenotype. Upon reaching their destination, human axons established ultrastructural correlates of synaptic connections with host neurons. Together, these data indicate that neurons derived from human pluripotent stem cells are endowed with a remarkable potential to establish orthotopic long-range projections in the adult mammalian brain.     

Transplantation of brain tissue in the brain of adult rats

Summary Brain tissues obtained from rat embryos were transplanted in the forebrain and/or cerebellum of the adult rats. The transplants survived, grew and achieved normal cellular and cytoarchitectural differentiation. They had become anatomically integrated with the host brain. The animals did not show any obviously detectable abnormal behavior or pathology of the brain. The transplants survived as long as the animals did suggesting that they had become a part and parcel of the host brain.Supported by research grants NS-08817 and CA-14650 from N.I.H.     

Stereotaxic technique for transplantation of neural tissues in the brain of adult rats

Summary A technique of neural transplantation in the brains of adult animals, using stereotaxic apparatus, is described. It facilitates transplantation of neural tissues of small volumes in precisely defined structures of the host brain, and yields a high percentage of successful transplantations.Supported by N.I.H. Research grant No. NS-08817. Suggestions from Drs N. Mangini, M. M. Oblinger and J. Weibers on various aspects of this procedure are gratefully acknowledged.     

Attempt to alter antigenic structure of normal tissues by treatment with dimethyl-triazeno-imidazole-carboxamide in vivo

Summary The antigenic structure of normal skin and spleen cells has been investigated following in vivo treatment with the compound DIC. In experiments involving skin grafting in the normal and sensitized host, cross sensitization with a DIC-antigenic lymphoma and³H-thymidine incorporation by lymphocytes cultured with DIC-treated spleen cells, new antigens on DIC-treated tissues were not demonstrated.Research supported in part by Contract No. 74.00237.04 from C.N.R., Rome.We wish to thank Mr.C. R. Reeder of the Mammalian Genetics and Animal Production Section of NCI, NIH, Bethesda, Maryland, USA, for breeding and providing the animals, and Serpero Foundation, Milan, for support. The proficient technical assistance of Ms.C. Cattoi andD. Peroni is also acknowledged.     

Ammoniacal silver staining of normal and inflamed rat synovial membrane

Summary An ammoniacal silver technique was used to detect changes in histone profiles in normal rats and rats with adjuvant-induced arthritis. Under these conditions histone staining reactions change at times when synovial cells are becoming more metabolically active.Acknowledgments: Supported by Biomedical Research Development Grant No. ISO08RR09016-01 from the National Institutes of Health, by grants to both authors from the Marquette University Committee on Research and by Marquette University School of Dentistry.     

Transplantation of neural tissues in the brains of laboratory mammals: Technical details and comments

Summary Various technical details on the transplantation of the embryonic neural tissues in the brains of the neonatal and adult rats are presented. Conditions determining successful or leading to unsuccessful survival, growth and differentiation of these transplants are critically examined.Supported by Research grants NS. 08817 and CA. 14650 from N.I.H.     

Immunosuppressive effect of a mouse placenta fraction on H-2 incompatible split heart allografts

Summary A soluble placenta fraction from mice (A.CA) mated with H-2 histoincompatible males (A/Sn) significantly prolonged the survival of heterotopic A/Sn heart transplants in A.CA recipients. No prolongation of A/Sn heart graft survival was obtained with the corresponding A.CA placenta fraction after A.CA × A.CA mating.The work was supported by the Danish Medical Research Council (Project No. 512-3088).     

Transplantation into the mammalian adult spinal cord

Summary Embryonic cerebral cortical tissue obtained from rat embryos of 15-day gestation was transplanted into the cervical spinal cord of adult rats. The cortical transplants survived, grew, and established connections with the host animal's spinal cord. In other animals, knife lesions were first made in the host's spinal cord, and then embryonic cortical tissue was transplanted into the site of the lesion. The cortical transplants in these animals were observed to become an integral part of the host animal's spinal cord.     

Light and electron microscopic evidence of hypothalamic afferences originating from the hippocampus in the pigeon

Summary Degenerating nervous fibres and synaptic boutons were demonstrated in the nuclei posterior medialis hypothalami after hippocampal lesions in the pigeon (light and electron microscopy).Acknowledgments. The authors are indebted to Mr.Louis Dongan for histological assistance. Parts of this experiment were supported by a grant from the C. N. R. S. (ERA No. 85).     

Experimental production of local osteomalacia

Summary The newly deposited bone which was laid down on necrotic bone in the experimentally produced osteochondral chips in the knee joint of 16 sheep and rabbits remained unmineralized and undermineralized in which respect it resembled osteomalatic bone. Local factors which interfere with the mineralisation of a new covering bone should be considered in the pathogenesis of osteomalacia, in healing of aseptic bone necrosis and fractures, and incorporation and fate of bone transplants.This project was partly supported by the Action Research for the Crippled Child, grant No. A/8/877.     

Persistence of infradian body weight cycles in castrated dormice (Glis glis)

Summary Male dormice were castrated at 2 phases of their infradian body weight cycles. No consistent changes were found in cycle period, amplitude, or absolute weights of the dormice following castration. Unlike other mammals, body weights of dormice appear unaffected by castration. Although both body weight and reproductive condition vary on an infradian basis, the changes in body weight appear to be programmed independently from changes in gonadal function.Acknowledgments. I would like to thank R. Melnyk, N. Mrosovsky, and J. D. Hallonquist for much helpful criticism and K. Lang and J. Kenyon for invaluable technical help. Research support was provided by a National Sciences and Engineering Research Council of Canada grant to N. Mrosovsky.     

SEM observation of cultured,mitogen-stimulated leukocytes. Cells obtained from patients with acute myeloblastic and chronic lymphocytic leukemias

Summary SEM observation of acute myeloblastic leukemia cells, incubated for 20 h with the mitogens pokeweed and phytohaemagglutinin, showed these to have elongated structures that were either smooth or partially covered by thumblike figures. By contrast, the chronic lymphocytic leukemia cells possessed more compact shapes and some were covered with blebs of varying sizes.Supported by grant No. A3624 from the Natural Sciences and Engineering Research Council of Canada.We would like to acknowledge the help of Mr Jean-Luc Verville and Mrs Diane Keating from this Department. Our thanks also go to Dr J.F. Perdue, Lady Davis Institute for Medical Research of the Jewish General Hospital, Montreal, Canada, for the very generous use of his equipment and also to Mr Pierre Daigneault from M. E. C. A. Laboratories.     

Spatial distribution of signal and adaptive sensitivity in the receptive field surrounds of cat retinal ganglion cells

Summary A comparison was made between adaptive and signal sensitivity profiles of the surround response mechanism of cat retinal ganglion cells. The 2 profiles were found to be similar for X cells but the surrounds of Y cells appear to pool adaptation over a smaller retinal region than they pool signals. Acknowledgments. We wish to thank Mr O. Navarro for his valuable technical assistance. This research is supported by Public Health Service grant No. EY 00701.     

Improved separation at low temperature of glycoproteins by Con A-Sepharose affinity chromatography in the presence of sodium dodecyl sulfate (SDS)

Summary The Con A-Sepharose affinity chromatography of glycoproteins was even more effective at 4°C than that at room temperature (26–28°C) in the presence of sodium dodecyl sulfate (SDS). Application of this methodology to the seperation of several glycoproteins from SDS-solubilized membrane proteins in rat cerebellum, including a glycoprotein characteristics of the Purkinje cells, was sucessful.Acknowledgments. A part of this research was supported by a Grantin-Aid for Scientific Research from the Ministry of Education, Science and Culture (No. 58480150), and also by a grant from National Center of Nervous, Mental and Muscular Disorders (NCNMMD) of the Ministry of Health and Welfare (No.83-11) in Japan.     

14-3-2 protein in rat brain synapses

Summary The distribution of the 14-3-2 protein in rat brain synapses was studied by immuno electron microscopy. The protein was localized to the postsynaptic web and to the postsynaptic membrane, but was also prominent both in the presynaptic membrane and in the presynaptic densities. No significant activity was observed in the synaptic vesicles.Acknowledgments. Our sincere thanks to Mrs Ulla Svedin, Eng., for skilled technical assistance. This work was supported by grants from the Swedish Medical Research Council, the Medical Faculty of Göteborg, Tore Nilson's Foundation for Medical Research and by the Swedish-Italian Group of Neurobiology. A. G. received financial support from Consiglio Nazionale delle Ricerche (CNR, ROME).     

Immunocytochemical demonstration of contractile cells in the human ovarian follicle

Summary Actin-and myosin-like immunoreactivity is found in cells located in the theca externa of the follicle wall of the human ovary, and corresponding to previously observed myoid cells. The immunocytochemical observation provides direct structural evidence that non-vascular contractile cells are also present in the follicle wall in humans. As expected, perifollicular blood vessels showed a positive immunoreaction for actin and myosin in their smooth muscle walls.This work was supported by the Swedish Medical Research Council, grant No. 14X-732/5680.     

Different types of synaptic vesicles in axons of the retractor penis muscle of the bull

Summary Three types of axon profiles were observed in the smooth muscle of the retractor penis and the penile artery of the bull: 1. profiles containing small granular vesicles, presumably representing adrenergic axons; 2. profiles containing small agranular vesicles, presumably representing cholinergic axons; 3. profiles containing numerous large and small granular vesicles. The third type of profile was not found in the vas deferens or the metatarsal artery. It is therefore possible that this type of profile represents the non-adrenergic, non-cholinergic inhibitory nerves, the presence of which has previously been pharmacologically indicated in these tissues.This study has been supported by grants from the Sigrid Jusélius Foundation (to O. E.), from the Medical Research Council of the Academy of Finland (to E. K.) and from the Magnus Bergvall Memorial Fund (to N. O. S.). Excellent technical assistance by Mrs.Paula Hasenson is gratefully acknowledged.     

Comparative anatomy of the host-fungus interface in mycorrhizas

Summary There are several types of mycorrhizal symbiosis (ectomycorrhiza, endomycorrhiza, ectendomycorrhiza), and the interfaces between the host-plant and the fungal symbiont have different organizations. The interfaces between the partners are always limited on the one side by the fungal plasmalemma and on the other side by the plasmalemma of the host plant or the perisymbiont membrane derived from it The cytoplasms of the partners are therefore separated by a mixed apoplast consisting of a fungal wall and a host wall or an apposition layer.     

Elevated kidney glucosyltransferase activity in genetic prediabetic mice

Summary Glucosyltransferase activity in the renal cortex of genetic diabetic KK mice was significantly increased at 40 days of age when compared to that of Swiss albino and F₁ hybrid mice. This increase in enzyme activity in the absence of glucose intolerance can be regarded as an earlier genetic marker for the diagnosis of diabetic microangiopathy.Acknowledgments. This research was supported in part by the General Research Support Grant No. RR-05398 from the General Research Support Branch, Division of Research Resources, National Institutes of Health, National Institutes of Health Training Grant No. 5-T01-AM-05617-06, Hope for Diabetics Foundation, Inc., and Pfizer Research Laboratories. Dr.R. A. Camerini-Davalos was a Career Scientist of the Health Research Council of the City of New York, and Drs.A. S. Reddi andC.A. Velasco were N. I. H. Trainees in Diabetes Mellitus during part of this study.