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E Buse

Publications and source records attributed to E Buse.

27 records · Page 2Linked to original sources
PubMed1987

The mouse neural plate as starting material for studying neuronal differentiation in vitro.

Tissue from the mouse neural plate and neural tube was studied, by light and electron microscopy, as starting material for tissue culture. In vivo, up to embryonic day 9 (E 9, stage Th 14; Theiler 1972) all neuroepithelial cells of the neural plate were mitotically active. As judged from their light microscopic or ultrastructural appearance, they could hardly be distinguished from one another or from neuroepithelial cells of more mature embryos. The earliest few immature neurons in the mesencephalic anlage were discernible on day 9 1/2 (stage Th 15) in the prospective intermediate layer of the neural tube, concomitantly with the development of processes containing neurotubules and vesicles which were oriented in parallel to the basal lamina. For tissue culture, explants of the mesencephalic anlage of embryonic days 8 (Th 12/13), 9 1/2 (Th 15), and 11 (Th 18) were kept in vitro and their development was compared with each other and with the corresponding developmental stage in vivo in the initial phase of culture (e.g., E 8, day of explanation, kept in vitro for 2 days, E 10 in vivo being the stage for comparison). The study demonstrated that further in vitro development proceeded in an accelerated manner, independent of the developmental stage of the embryo from which the tissue was explanted. In vitro, proliferation of the explanted neuronal progenitor cells stopped in all explants within 24 h of culture as revealed by autoradiographic and electron microscopic techniques. Cytoplasmic transformation was observed corresponding to that found in vivo, but always greatly accelerated. Earliest axons had formed after 24 h in vitro; synapses with clear vesicles and dense core vesicles were observed after at least 3 days in culture in all explants regardless of age at the time of explantation (E 8 or E 11). The present ultrastructural results indicate that prospective neurons within the neuroepithelium of the neural plate and early neural tube were immediately able to develop into neurons without the complete sequence of mitotic events normally occurring under in vivo conditions.

Animals↗
PubMed1987

Ventricular cells from the mouse neural plate, stage Theiler 12, transform into different neuronal cell classes in vitro.

The rostral parts of the cephalic neural plate and neural crest of mice, stage Theiler 12, were prepared and cultured. At that stage of development they exclusively consist of proliferative ventricular cells, which do not yet display vimentin and neurofilament immunoreactivity. 3H-thymidine autoradiography showed that the progenitor cells of neurons became postmitotic as soon as they were taken into culture. The neurofilament protein (kD 68) was immunocytochemically demonstrable from day 2 in culture, while immunoreactivity to vimentin was never observed. The neurons, prematurely developed from the neuroepithelium of stage Theiler 12-embryos, were identified by their histological and immunocytochemical properties. They gave distinct patterns of immunoreactivity to neuropeptides and anti-serotonin antibodies. Anti-serotonin and anti-somatostatin antibodies reacted from the 3rd day of culture. Antibodies against ACTH, luliberin, substance P and vasopressin gave positive reactions at day 7. Two classes of neurons, the serotonin and the large substance P-immunoreactive ones, were recognized by both immunoreactivity and morphology. The serotonin immunoreactive neurons usually were of a multipolar shape and had a long, varicose axon that was heavily stained, particularly at its distal third. The perikarya appeared in limited areas of the cultured tissue. They grew in the vicinity of each other, but never in densely packed aggregates. The large neurons, reacting heavily with antibodies against substance P and faintly with all the other neuropeptide antibodies applied, were up to 50 micron in diameter and usually occurred in 20-40 cells per preparation of half a neural plate. The results suggest that at least some classes of neurons can develop from the cultured neural plates of stage Th12.

Adrenocorticotropic Hormone↗
PubMed1987

Development of serotoninergic neurons from ventricular cells of the mouse neural plate in vitro.

Cephalic neural plates and neural tubes of mice (pros- and rhombencephalic anlagen), developmental stages Theiler 11-18 [Th 11-18; embryonic day 7 1/2-11 (E7 1/2-11)], were prepared and cultured in a plasma clot with horse serum-containing MEM medium. Differentiation of the ventricular cells was studied in order to investigate the expression of serotoninergic properties. Serotoninergic neurons were not detected in preparations derived from neural plates of stage Th 11 (E7 1/2), but were demonstrated in increasing numbers from the early stage Th 12 (E8) onwards. The exclusively originated from the rhombencephalic floor caudal to the mesencephalic flexure. The serotoninergic neurons developed from these areas, irrespective of whether being cultured in their natural position within the neural plate, or separated as microcultures, or transplanted into the prosencephalic anlage. Every other region of the neural plate remained free of serotoninergic neurons. The in vitro findings are highly reproducible due to the following properties: the morphological and immunocytochemical peculiarities of the serotoninergic neurons, their tendency to appear in increasing numbers with age, their localization within the cultured neural plates and their appearance in all cultures from stage Th 12 (E8) on. Due to these findings it is considered possible that the progenitor cells of serotoninergic neurons might already have been determined within distinct areas in the mouse neural plates as early as stage Th 12 (E8).

Animals↗
PubMed1985

A method for the collection of defined areas from the embryonic rat brain for cell and tissue culture.

Tissue for the culture of cerebral neurons has frequently been taken from brains of the embryonic rats. In many cases it was impossible to obtain regularly and reproducibly small, defined pieces of tissue, e.g. diencephalic nuclei, of the extremely soft embryonic cerebral tissue. On the other hand, as a basis for tissue cultures, well defined samples are more and more considered essential. Therefore a method for collecting samples of defined small regions from the di- and mesencephalic rat brain, 17 days of gestation, was developed. It is applicable to cell and tissue culture. Embryonic brains are prepared aseptically and embedded in congealing Agarose. Stabilized in this gel they are cut into 225 micron slices using a tissue chopper. Tissue samples desired for culture are then punched out from the respective brain slice, which previously had been compared with corresponding reference micrographs. The correct localization of the tissue punch within the fresh brain slice is controlled histologically. The embedding procedure for performing the histology of the brain slices of 225 micron width is described. For application of the introduced method, coordinates for slicing and histological reference micrographs are given for di- and mesencephalic areas.

Animals↗
PubMed1983

A method for defined sectioning of fresh young brains and collection of small regions for cell and tissue culture.

A method for the collection of defined small regions from fresh brain under sterile conditions is described. Its reproducibility allows the cultivation of well-defined, corresponding regions from similar brains. After controlled orientation in agarose, the brain can be sectioned by means of a Vibratome in spite of its softness. The section level is defined by co-ordinates of a stereotaxic atlas, produced for this purpose from brains orientated in the same way. Areas desired for cultivation are punched out from tissue slices with 200-550 microns diameter needles according to the atlas pictures. The plugs can then be stored in cold buffer solution until preparation for culture. Exact locations of tissue samples collected can be determined histologically. Either whole or dissociated plugs cultivated by a plasma clot technique lead to morphologically differentiating neurons surviving for more than or up to 14 days, respectively.

Animals↗
PubMed1983

Single neuron cultivation of embryonic and perinatal rabbit or rat brains based on plasma clot technique.

Isolated neuronal cells dissociated from the brain of embryonic rabbits on the sixteenth day of gestation and of perinatal rats (eighteenth embryonic day, to E18, thirteenth day postnatum, p.n. 13) were selectively cultured using a plasma clot technique. The cells grown were shown to be neurons by means of the neuron-specific synaptosomal plasma membrane antibody (SPM). They differentiated at a very high frequency from rounded cells lacking processes into different shapes characteristic for several neuronal cell types. Morphological differences could be distinguished even after 24 h in culture. The neurons differentiated in vitro for up to 11 days, apparently without need of any direct intercellular contact. Cells caught inside the plasma clot were prevented from decreasing in number. This provides the opportunity to culture few neurons even from an extremely small area of a single brain. As an example, different cell types are shown originating from rat cerebella aged E18 to p.n. 13. Their appearance apparently corresponds to the genesis of cerebellar cell types, as is known from the in vivo situation. The high degree of characteristic neuronal differentiation and the prevention of direct intercellular contacts indicate that this culture method may serve as an in vitro assay for genetically fixed properties acquired in vivo.

Animals↗
PubMed1979

[Scanning microscopical observations on the foregut structures o mosquitoes and their role for the ingestion of microfilariae (author's transl)].

Experiments on the transmission of Brugia malayi by various mosquitoes had shown that microfilariae ingested by some species were badly damaged when they reached the stomach, but were much less hurt in others. The structures of the foregut likely to cause these injuries, were investigated and documented by scanning microscope techniques. In Anopheles albimanus, A. arabiensis, A. stephensi and A. pharoensis which have well developed armatures the microfilariae showed a high rate of destruction. In A. stroparvus as well as in Aedes aegypti, Ae. togoi and Culex fatigans in which these structures are missing or poorly developed the larvae were much less affected. From the size, shape and position of the different papillae, spines, rods and cones observed it can be concluded and confirmed that the pharyngeal armature (buccopharyngeal bar) will be by far the most important structure responsible for the injuries of the microfilariae. However, it appears that the characteristics of different filaria species can play an important role in preventing such damages.

Animals↗
PubMed1978

Effect of cyclic AMP on transformation and proliferation of leishmania cells.

A correlation between cyclic AMP (adenosine 3' : 5'-monophosphate) concentration within Leishmania cells and proliferation and transformation is demonstrated. By addition of dibutyryl cyclic AMP and cyclic AMP-phosphodiesterase inhibitors to the culture medium the intracellular level of cyclic AMP was increased. In the presence of 1mM caffeine the level of cyclic AMP accumulated in L. tropica promastigotes from 90 pmoles up to 380 pmoles per 10(9) cells, whereas the proliferation rate decreased to 50%. In the case of L. donovani the transformation of amastigotes to promastigotes was inhibited by addition of dibutyryl cyclic AMP as well as caffeine and papaverine. Especially caffeine (2mM) and papaverine (0.1mM) reduced the transformation rate to less than 5% after 48 h, compared to 35% of the control.

Bucladesine↗