RNA is the messenger from the nucleus that tells the ribosome what to make. The DNA sequences that create the RNA are called genes. It was only learned the las

RNA is the messenger from the nucleus that tells the ribosome what to make. The DNA sequences that create the RNA are called genes. It was only learned the last few decades that genes can be turned off/on. This is how a single embryo cell can produce all the different cells in our body. Unfortunately they chose the word expressed for this concept. What they are saying is they want to study the amygdala aka the primitive pre-evolutionary part of our brain we share with other creatures. It is said the primitive brain controls breathing, heart rate,fear and anger. It is also said emotions like fear or anger is our brain’s faulty perception of our body’s response to all the adrenaline the amygdala is initiates. They know the amygdala has different types of cells. To learn why certain cells malfunction, and cause depression and other disorders, they are studying DNA sequences.