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  • Rat  (49)
  • Springer  (49)
  • Annual Reviews
  • 1985-1989  (26)
  • 1980-1984  (14)
  • 1975-1979  (9)
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Year
  • 11
    Electronic Resource
    Electronic Resource
    A serial-section study of perforated synapses in rat neocortex (1987)
    Springer
    Cell & tissue research 247 (1987), S. 565-572 
    Details
    ISSN: 1432-0878
    Keywords: Synapses ; Perforated synapses ; Synaptic plasticity ; Serial section reconstructions ; Synaptic curvature ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The morphology of perforated synapses in the molecular layer of rat parietal cortex has been studied in 28-day-old animals. Of the perforated synapses analyzed, 92% were axospinous and of these all had asymmetrical contacts. A spinule was present in 20% of them, and 63% had a negative curvature (concave with respect to the presynaptic terminal) overall. Up to 95% of perforated synapses had one or more negatively-curved segments. The perforated synapses studied were characterized by postsynaptic densities (PSD) with a mean length of 581 nm, compared with 233 nm for non-perforated synapses. A study of over 100 serially sectioned synapses demonstrated that, in perforated synapses, the PSD and perforations often had a highly irregular shape and arrangement, the site of the perforation frequently projected into the presynaptic terminal, and coated evaginations of membrane, or coated vesicles, were sometimes found at the site of a perforation or towards the periphery of perforated PSDs. Preliminary reconstructions of perforated synapses suggest that, for descriptive purposes, three types can be recognized. Criteria are formulated for determining, on the basis of a study of single sections, which non-perforated profiles belong to perforated synapses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00215750
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  • 12
    Electronic Resource
    Electronic Resource
    Determination of the numerical density of perforated synapses in rat neocortex (1987)
    Springer
    Cell & tissue research 248 (1987), S. 399-407 
    Details
    ISSN: 1432-0878
    Keywords: Synapses ; Perforated synapses ; Synaptic plasticity ; Synaptic density ; Morphometry ; Serial sections ; Section thickness ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The numerical density and frequency of perforated synapses in the molecular layer of rat parietal cortex have been determined using 4 procedures in an attempt to overcome problems associated with the size and complex three-dimensional shape of perforated synapses. The following procedures were compared: A, single-section analysis; B, adjacent-section analysis; C, semi-serial-section analysis; and D, complete serial-section analysis. All procedures made use of an unbiased counting rule. Estimates of the numerical density of perforated synapses ranged from 0.06 to 0.27×109 mm-3, and that of all synapses (non-perforated and perforated) from 1.88 to 2.50×109 mm-3. The frequency of perforated synapses varied from 4.5 to 18.0%. Procedures B (adjacent-section analysis) and D (complete serial-section analysis), neither of which utilize assumptions regarding the shape of synapses, produced comparable results (numerical density of perforated synapses 0.19–0.27×109 mm-3, and of all synapses 2.24–2.45×109 mm-3; frequency of perforated synapses 8.6–10.9%). The frequency of perforated synapses appeared to be underestimated by procedure A (single section analysis; 4.5%) and overestimated by C (semi-serial section analysis; 18%). It is concluded that adjacent-section analysis is the most efficient and effective procedure for determining the numerical density and frequency of complex particles, such as perforated synapses. There is, however, no significant difference in the performance of this procedure compared with that of single-section analysis, for determining the numerical density of synapses in general. Nevertheless, inherent problems of bias within the single-section procedure make the adjacent section method the procedure of choice.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218208
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  • 13
    Electronic Resource
    Electronic Resource
    Does neonatal androgen modulate uptake and retention of 3H-estradiol in gonadotrophs and lactotrophs? (1985)
    Springer
    Cell & tissue research 242 (1985), S. 629-632 
    Details
    ISSN: 1432-0878
    Keywords: Androgen ; Estrogen ; Gonadotrophs ; Lactotrophs ; Autoradiography ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Castrated adult male and female and androgenized female rats (AS rats) were injected i.v. with 3H-estradiol (E2). Nuclear uptake and retention of the 3H-steroid was examined in pituitary luteinizing hormone (LH) and prolactin (PRL) cells by the combined techniques of autoradiography and immunocytochemistry. About 80% of PRL cells were found to concentrate the radioactive steroid compound in all experimental groups, while 89%, 82% and 68% of LH cells were found to be labeled in AS rats, normal female and male rats, respectively. This suggests that there are subpopulations of LH or PRL cells that contain no or, if any, small numbers of E2 receptor. Statistical analysis revealed that PRL cells take up more radioactivity than LH cells in male rats, while there is no significant difference between female and AS rats. Variations in E2 uptake (coefficient of variation) was higher in LH cells than in PRL cells in male rats and in AS rats. In females, on the contrary, coefficient of variation was larger in PRL cells. Thus the characteristics of nuclear uptake and retention of estradiol in LH and PRL cells appear to be modulated in part by neonatal androgen since the pattern found in AS rats is different than that found in normal male and female rats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225429
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  • 14
    Electronic Resource
    Electronic Resource
    Dihydrotestosterone induces a sexual dimorphism in estrogen uptake by specific anterior pituitary cell types in vivo (1987)
    Springer
    Cell & tissue research 249 (1987), S. 477-479 
    Details
    ISSN: 1432-0878
    Keywords: Androgen ; Estrogen ; Pituitary ; Autoradiography ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Castrated male and female rats pretreated with dihydrotestosterone (DHT) were injected i.v. with 3H-estradiol (E2). Nuclear uptake and retention of 3H-E2 was measured in each of five cell types of the anterior pituitary gland using a combined quantitative autoradiographic and immunocytochemical procedure. In non-pretreated groups, each cell type bound a characteristic amount of ligand but no sex differences were apparent. DHT pretreatment, however, caused a significant decrease in 3H-E2 retention by gonadotrophs in both males and females. The treatment also caused a decrease in binding by lactotrophs and somatotrophs, but only in the females. No other cell types were altered. Thus, androgen appears to modulate E2 binding and retention by pituitary cells in both a cell-type and sexdependent manner. Our results also indicate that the inhibitory effects of androgens on E2 binding by the pituitary gland is more complex than can be explained by simple competition for the estrogen receptor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00215534
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  • 15
    Electronic Resource
    Electronic Resource
    Intercellular spaces between macula densa cells: An ultrastructural study comparing high pressure perfusion fixation with in situ drip-fixation of rat kidney (1987)
    Springer
    Cell & tissue research 250 (1987), S. 461-464 
    Details
    ISSN: 1432-0878
    Keywords: Macula densa ; Intercellular spaces ; Ultrastructure ; Frusemide ; Tubulo-glomerular feedback ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In situ drip-fixation of superficial glomeruli and tubules in the rat kidney verified the results obtained from high pressure perfusion fixation studies indicating that distinct spaces normally exist between the cells of the macula densa. Following treatment with frusemide these intercellular spaces between the macula densa cells became closed in both drip-fixed and perfusion-fixed kidneys. These findings suggest that the variability of extracellular compartmentation found in the macula densa is unlikely to be an artifact but most likely represents changes in the in vivo status of the macula densa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219092
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  • 16
    Electronic Resource
    Electronic Resource
    An immunohistochemical study of adenohypophyseal cells containing follicle-stimulating hormone and luteinizing hormone during the phase of selective follicle-stimulating hormone release in postnatal female rats (1987)
    Springer
    Cell & tissue research 250 (1987), S. 689-693 
    Details
    ISSN: 1432-0878
    Keywords: Anterior pituitary gland ; FSH cells ; LH cells ; Development ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Serum concentration of follicle-stimulating hormone (FSH) in the juvenile female rat increases independently from that of luteinizing hormone (LH). The objective of this study was to determine whether this increase in serum FSH is accompanied by a proliferation of FSH-cells greater than the proliferation of LH-cells. Thus, we measured circulating FSH and LH in female rats on days 3, 10, 13, 17, and 20, calculated the percentages of adenohypophyseal cells that contained FSH or LH on days 3, 10, and 20, and determined whether cells containing only FSH existed on day 10. Serum FSH concentrations on days 10 and 13 were significantly greater than those on days 3, 17, or 20. No differences existed in serum LH concentrations. Cells containing FSH or LH were distributed throughout the entire adenohypophyses of 3, 10, and 20-day-old females. Clusters of these cells were observed in the ventral regions of adenohypophyses of 3-day-old females. The percentages of adenohypophyseal cells containing FSH increased significantly from ∼9% in 3-day-old rats to ∼17% in 10-day-old rats and then decreased to ∼14% in 20-day-old animals. At all ages the percentages of adenohypophyseal cells containing FSH were similar to the percentages of cells containing LH. At 10 days of age, all cells containing FSH also contained LH and all cells containing LH also contained FSH. These data suggest that the increase in serum FSH in the juvenile female rat is associated with an increase in the percentage of adenohypophyseal cells containing FSH and that at this time all cells containing FSH also contain LH.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218964
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  • 17
    Electronic Resource
    Electronic Resource
    The early postnatal development of the primary immune response in rat popliteal lymph node, stimulated with thymus-independent type-1 and type-2 antigens (1987)
    Springer
    Cell & tissue research 250 (1987), S. 695-699 
    Details
    ISSN: 1432-0878
    Keywords: Primary immune response ; Thymus-independent antigens ; Development, ontogenetic ; Lymph nodes ; Spleen ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To examine the development of the postnatal immune response to thymus-independent type-1 (TI-type 1) and TI type-2 antigens, respectively, trinitrophenyl-lipopolysaccharide (TNP-LPS) or TNP-Ficoll was injected subcutaneously into the hind footpads of young rats of various ages. After 5 days the popliteal lymph nodes (PLNs) were removed and the localization pattern of specific anti-TNP antibody-containing cells was studied. The first specific antibody-containing cells elicited in rats by TNP-LPS appeared in animals at day 19 after birth. The results suggest that the development of these cells from lymphocyte to plasma cell occurs while they migrate from cortex to medulla. An unexpected finding was the low response to TNP-Ficoll in PLN; from 6 weeks after birth only very few specific antibody-containing cells were found. However, in the spleen numerous anti-TNP antibody-containing cells were found in the periarteriolar lymphocyte sheaths. To test the exclusive role of the spleen in the appearance of anti-TNP antibody-containing cells in lymph node after subcutaneous administration of TNP-Ficoll, the experiment was repeated in rats that had been splenectomized. Evidence from these experiments suggests that the spleen plays a major role in the appearance of the above-mentioned cells in lymph nodes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218965
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  • 18
    Electronic Resource
    Electronic Resource
    Adhesion, proliferation, and adipogenesis in primary rat cell cultures: effects of collagenous substrata, fibronectin, and serum (1988)
    Springer
    Cell & tissue research 251 (1988), S. 123-128 
    Details
    ISSN: 1432-0878
    Keywords: Adipocyte ; Primary culture ; Collagen ; Fibronectin ; Serum ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of collagenous substrata, fibronectin, and fetal bovine serum on the adhesion, proliferation, and adipogenesis of rat stromal-vascular cells are reported. There was no effect on initial stromal-vascular cell-attachment by fetal bovine serum or fibronectin. The number of cells attached to a hydrated collagen-gel was almost twice (P〈0.04) the number attached to dried collagen-gel or dried denatured collagen-gel. Total number of cells after 5 days in culture was similar among the collagenous substrata and among the treatments with or without fibronectin in the growth media. Total number of cells increased significantly (P〈0.02) with 10% FBS. Adipocytic formation was inhibited by hydrated collagen-gel (P〈0.02) compared to dried collagen-gel or dried, denatured collagenous substrata. An interaction occurred between dried, denatured gel and fetal bovine serum so that total formation of adipocytes increased by increasing the level of fetal bovine serum (P〈0.07). Adipocytic formation was inhibited by hydrated collagen-gel at all levels of fetal bovine serum. The percentage of cells that converted to adipocytes was significantly lower (P〈0.01) on hydrated collagen-gel compared to dried, denatured or dried collagen-gel. Percentage of conversion was not significantly different among levels of fetal bovine serum, although this percentage increased as fetal bovine serum level increased. Adipocytic conversion was not different between fibronectin-treated or untreated cells. Morphology of stromal vascular cells was similar on dried collagen and dried, denatured collagen-gel, but tended to remain bipolar on hydrated collagen-gel. These studies indicate that fetal bovine serum in combination with the extracellular matrix (dried, denatured collagen) increased the differentiation of rat stromal-vascular cells into adipocytes, and that hydrated collagen inhibited differentiation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00215456
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  • 19
    Electronic Resource
    Electronic Resource
    Effects of pimozide on the ultrastructure of the pars intermedia in the rat (1981)
    Springer
    Cell & tissue research 217 (1981), S. 397-403 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary gland ; Rat ; MSH-cells ; Pimozide ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of pimozide, a dopamine receptor-blocking agent, were studied in the pars intermedia of the rat. The animals received 100 μg/100 g pimozide daily for 2, 5, 10, 15, and 20 days. Pimozide induces ultrastructural changes after 5 days of treatment. About 50% of the MSH-cells display characteristics of stimulation. Their cytoplasm is partially or totally depleted of secretory granules. The rough endoplasmic reticulum displays a network of interconnecting cisternae and ribbon-like structures. The well-developed Golgi complexes exhibit numerous dilatations of their cisternae, which contain electron-dense material. The nerve endings are not altered. Twenty days after treatment, the above-described changes have not decreased in magnitude. The present findings suggest that pimozide stimulates the mechanism of synthesis and release in some MSH-cells, most probably the elements underlying an inhibitory dopaminergic control.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233589
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  • 20
    Electronic Resource
    Electronic Resource
    Effects of chronic exercise on the ultrastructure of the adrenocortical cells in the rat (1976)
    Springer
    Cell & tissue research 168 (1976), S. 261-270 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Exercise ; Rat ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Four groups of male rats were exercised for periods of 2, 4, 6, and 8 weeks with controls in each group. As a result of chronic exercise there was an increase in the width of the zona fasciculata of the adrenal cortex. Also, there was an increase in the number and size of the mitochondria, and an increase in the quantity of smooth endoplasmic reticulum, and during the first 4 weeks of exercise an increase in the number of lipid droplets in the zona fasciculata. The close relationship between the smooth endoplasmic reticulum and the mitochondria, and the relationship between the smooth endoplasmic reticulum and the lipid droplets suggests a possible means for a transport mechanism for movement of precursors between these organelles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00215882
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