Three-Dimensional Ultrastructural and Volume Analysis of the Redundant Nuclear Envelope of Developing and Matured Sperm in Mice

Three-dimensional Ultrastructural and Anatomical Analysis of the Relationship Between Subepithelial Stromal Cells and Shape of Basement Membrane of the Epithelium of Prostatic Duct in Mice

This study examined the three-dimensional (3D) ultrastructural relationship between subepithelial stromal cells (SESCs) and the basement membranes (BM) of the prostatic epithelium in mice. Three 13-week-old male C57BL/6 mice were used for analysis of the lower urinary tract via en bloc staining as well as 3D ultrastructural analysis of SESCs, stroma, and luminal and basal epithelial cells. Morphologically, two types of epithelial BMs were observed: wavy and straight. SESCs associated with straight BMs were sheet-like in structure and much larger than those associated with the wavy BMs, with occasional protrusions extending toward the BM. SESCs with wavy BMs were of two major types: one type was sheet-like and relatively large, frequently extending its projections toward the BM, whereas the other type was small and mostly did not extend its projections toward the BM. Some SESCs with wavy and straight BMs exhibited contact with nerves. However, none of the analyzed SESCs showed vascular contact. Our study revealed the relationship between SESCs and the BM of epithelia in the mouse prostatic duct. Each SESC had a distinctive morphology that matched the shape of the epithelial BM. SESCs could be a new target for research in the fields of anatomy and physiology.

Three-dimensional ultrastructural and anatomical analysis of prostatic neuroendocrine cells in mice

BACKGROUND

A few studies have examined the ultrastructure of prostatic neuroendocrine cells (NECs), and no study has focused on their ultrastructure in three dimensions. In this study, three-dimensional ultrastructural analysis of mouse prostatic NECs was performed to clarify their anatomical characteristics.

METHODS

Three 13-week-old male C57BL/6 mice were deeply anesthetized, perfused with physiological saline and 2% paraformaldehyde, and then placed in 2.5% glutaraldehyde in 0.1 M cacodylate (pH 7.3) buffer for electron microscopy. After perfusion, the lower urinary tract, which included the bladder, prostate, coagulation gland, seminal vesicle, upper vas deferens, and urethra, was removed, and the specimen was cut into small cubes and subjected to postfixation and en bloc staining. Three-dimensional ultrastructural analysis was performed on NECs, the surrounding cells, tissues, and nerves using focused ion beam/scanning electron microscope tomography.

RESULTS

Twenty-seven serial sections were used in the present study, and 32 mouse prostatic NECs were analyzed. Morphologically, the NECs could be classified into three types: flask, flat, and closed. Closed-shaped NECs were always adjacent to flask-shaped cells. The flask-shaped and flat NECs were in direct contact with the ductal lumen and always had microvilli at their contact points. Many of the NECs had accompanying nerves, some of which terminated on the surface in contact with the NEC.

CONCLUSIONS

Three-dimensional ultrastructural analysis of mouse prostatic NECs was performed. These cells can be classified into three types based on shape. Novel findings include the presence of microvilli at their points of contact with the ductal lumen and the presence of accompanying nerves.