A Multitude of Possibilities

What am I looking at?

This image shows a group of stem cells derived from the embryo of a marmoset (a small monkey) as they undergo the process of differentiation into neurons. Researchers isolated the cells from a marmoset embryo and provided them with the chemical signals required to produce neurons. The blue in the image represents the nuclei of all the cells (1). The blue half-dome in the middle of the image is a neurosphere (2), or a cluster of young neurons; it appears solid blue because these neurons are packed so tightly together that the blue staining of the nuclei becomes almost uniform. The green represents young neurons that have just differentiated (3). And the red and yellow represent more mature neurons that are sending projections out to contact other neurons (4).

Biology in the background

Most animals, including humans, start out as a ball of undifferentiated stem cells. Stem cells are cells that have the potential to transform into many different cell types. As development progresses, more and more stem cells differentiate into their final state. This process of differentiation is guided by a series of molecular (biochemical) signals that determine the fate of any given stem cell.

Researchers can isolate stem cells and provide them with the requisite signals to transform into a variety of different cell types. This allows the researchers to study the process of differentiation as it progresses, as well as the properties of the various cells the stem cells transform into. By learning what goes right and can go wrong during development, researchers can learn a lot about health and disease.

Primate stem cells are generally about 12 micrometers across, or roughly six times smaller than the width of a human hair.

Technique  

This image was created using confocal microscopy.