Using a process known as single-cell sequencing, scientists at Karolinska Institutet have produced a detailed map of cortical cell types and the genes active within them. The study, which was published online on February 19, 2015 in Science, marks the first time this method of analysis has been used on such a large scale on such complex tissue. The article was titled “Cell Types in the Mouse Cortex and Hippocampus Revealed by Single-Cell RNA-seq.” The team studied over three thousand cells, one at a time, and even managed to identify a number of hitherto unknown types. “If you compare the brain to a fruit salad, you could say that previous methods were like running the fruit through a blender and seeing what color juice you got from different parts of the brain,” says Dr. Sten Linnarsson, Senior Researcher in the Department of Medical Biochemistry and Biophysics. “But in recent years we’ve developed much more sensitive methods of analysis that allow us to see which genes are active in individual cells. This is like taking pieces of the fruit salad, examining them one by one and then sorting them into piles to see how many different kinds of fruit it contains, what they’re made up of, and how they interrelate.” The knowledge that all living organisms are built up of cells is almost 200 years old. Since the discovery was made by a group of 19th century German scientists, we have also learnt that the nature of a particular body tissue is determined by its constituent cells, which are, in turn, determined by which genes are active in their DNA. However, little is still known about how this happens in detail, especially as regards the brain, the body’s most complex organ.
Login Or Register To Read Full Story