Fun with Science Club®


			What can rats tell us about the human brain? Beth Tyler 06.01.01 Our brains process information from each of our sensory systems (sight, sound, touch, taste, and smell). The sensory systems send messages to the brain, which then creates a code for a particular sound or taste or smell. For example, there are over 1000 proteins on cells in our noses that recognize chemicals in the things we smell. When a chemical is present in a smell, it causes a cell to send a message to the brain, where a cell there recognizes it. Let’s say the smell for honey has ten different chemicals in it. When we smell honey, ten proteins in our noses will recognize the ten chemicals from honey. The cells those proteins are on will send a message to the brain. Ten cells in the brain will recognize the ten messages sent from the nose. These ten cells in the brain create a code for the smell of honey. This is how humans and many other animals process smells. Recently, scientists have been able to observe these brain processes happening in rats. First, they give the rat some anesthesia, putting it to sleep for awhile. Next, they shine light onto the surface of the brain where the olfactory (sense of smell) system is. Light shines back from the brain according to what cells are in action. When scientists put different smells up to the rat’s nose, they see different light patterns shining back from the brain. Using this technique, scientists can unlock the brain’s olfactory system code.


			Barinaga, Marcia. 1999. Mapping smells in the brain. Science 285: 508.