The Hidden World of Placenta Cells: A Closer Look

The placenta is a remarkable organ that connects a mother and her baby during pregnancy. It has special cells called trophoblast cells. These cells form two distinct layers on the surface of tiny, tree-like structures called chorionic villi. One layer is the outer syncytiotrophoblast (STB), and the other is the inner cytotrophoblast (CTB) layer. Scientists are still trying to understand how CTB cells change during pregnancy. A recent study used advanced techniques to get a better look at these cells. They used a method called Fast Red immunohistochemistry to highlight the CTB cells. This method uses special markers to make the cells visible under a microscope.The study also used a technique called serial block-face scanning electron microscopy (SBF-SEM). This allows scientists to see the cells in 3D. They found that CTB cells have a unique shape. In the outer parts of the villi, they are thin and flat, with many projections. This makes them look like spiders wrapping around grape-like structures called terminal villi. In the inner parts of the villi, the CTB cells are thicker and have a more block-like shape. They cover the surface of the villi. The SBF-SEM images showed that the CTB layer is like a thin mesh. The outer STB layer can reach through the small gaps in the CTB layer. This allows it to connect with the baby's blood vessels. These findings suggest that the terminal villi change their structure to help with the exchange of nutrients and waste between the mother and the baby. This is crucial for the baby's growth and development.