Three-dimensional analysis revealed that microglia have different structural features in different brain regions of mice

Tsetse flies (genus Glossina), the sole vectors of African trypanosomiasis, are distinct from most other insects, due to dramatic morphological and physiological adaptations required to support their unique biology. These adaptations are driven by demands associated with obligate hematophagy and viviparous reproduction. Obligate viviparity entails intrauterine larval development and the provision of maternal nutrients for the developing larvae. The reduced reproductive capacity/rate associated with this biology results in increased inter- and intra-sexual competition. Here, we use phase contrast microcomputed tomography (pcMicroCT) to analyze morphological adaptations associated with viviparous biology. These include (1) modifications facilitating abdominal distention required during blood feeding and pregnancy, (2) abdominal and uterine musculature adaptations for gestation and parturition of developed larvae, (3) reduced ovarian structure and capacity, (4) structural features of the male-derived spermatophore optimizing semen/sperm delivery and inhibition of insemination by competing males and (5) structural features of the milk gland facilitating nutrient incorporation and transfer into the uterus. Three-dimensional analysis of these features provides unprecedented opportunities for examination and discovery of internal morphological features not possible with traditional microscopy techniques and provides new opportunities for comparative morphological analyses over time and between species.

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In situ investigation of the primary recrystallization of alpha titanium in HVEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100110313 ◽

1978 ◽

Vol 36 (1) ◽

pp. 634-635

Author(s):

S. Naka ◽

R. Penelle ◽

R. Valle

Keyword(s):

Dimensional Analysis ◽

Texture Evolution ◽

Cold Work ◽

Three Dimensional ◽

Primary Recrystallization ◽

Thin Foils ◽

In Situ Investigation ◽

Grain Growth Model ◽

Alpha Titanium

The in situ experimentation technique in HVEM seems to be particularly suitable to clarify the processes involved in recrystallization. The material under investigation was unidirectionally cold-rolled titanium of commercial purity. The problem was approached in two different ways. The three-dimensional analysis of textures was used to describe the texture evolution during the primary recrystallization. Observations of bulk-annealed specimens or thin foils annealed in the microscope were also made in order to provide information concerning the mechanisms involved in the formation of new grains. In contrast to the already published work on titanium, this investigation takes into consideration different values of the cold-work ratio, the temperature and the annealing time.Two different models are commonly used to explain the recrystallization textures i.e. the selective grain growth model (Beck) or the oriented nucleation model (Burgers). The three-dimensional analysis of both the rolling and recrystallization textures was performed to identify the mechanismsl involved in the recrystallization of titanium.

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Methods for making stereoslides and -prints, with freeze-etched olfactory epithelium as example

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100113408 ◽

1984 ◽

Vol 42 ◽

pp. 704-705

Author(s):

Bert Ph. M. Menco ◽

Ido F. Menco ◽

Frans L.T. Verdonk

Keyword(s):

Electron Microscope ◽

Olfactory Epithelium ◽

Three Dimensional ◽

Supporting Cell ◽

Structural Features ◽

Extensive Study ◽

Sprague Dawley ◽

Freezing Method ◽

Respiratory Epithelia ◽

Three Dimensional Presentation

Previously we presented an extensive study of the distributions of intramembranous particles of structures in apical surfaces of nasal olfactory and respiratory epithelia of the Sprague-Dawley rat. For the same structures these distributions were compared in samples which were i) chemically fixed and cryo-protected with glycerol before cryo-fixation, after excision, and ii)ultra-rapidly frozen by means of the slam-freezing method. Since a three-dimensional presentation markedly improves visualization of structural features micrographs were presented as stereopairs. Two exposures were made by tiling the sample stage of the electron microscope 6° in either direction with an eucentric goniometer. The negatives (Agfa Pan 25 Professional) were reversed with Kodak Technical Pan Film 2415 developed in D76 1:1. The prints were made from these reversed negatives. As an example tight-junctional features of an olfactory supporting cell in a region where this cell conjoined with two other cells are presented (Fig. 1).

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