Dynamic Fidelity Control to the Central Auditory System: Synergistic Glycine/GABAergic Inhibition in the Cochlear Nucleus

What is it about?

In our brain, there are chemicals called GABA and glycine that help control how nerve cells communicate with each other. These chemicals are usually found in different parts of the brain and are used by different types of nerve cells as neurotransmitters. GABA is mainly used in parts of the brain responsible for thinking, while glycine is mainly used in the part that processes early stages of sensory information. In part of the brain involved in hearing, most of the control is exerted by glycine, but there are a few places where both GABA and glycine are used. We do not know much about why this happens and what it is beneficial for. To better understand the simultaneous use of two neurotransmitters, we studied a specific connection between nerve cells in the hearing part of the brain in young gerbils. This connection allowed us to see how the electrical signals are controlled by both GABA and glycine. We found that these two chemicals work together to control the electrical activity in the nerve cells. Glycine suppresses nerve cell activity strongly and quickly, like suddenly hitting the brakes on a car, while GABA helps control how long the brakes are pressed. This combination of brakes helps the brain process sounds better, especially loud or sudden ones. Using a computer model, we gained support for the experimental observations, showing that GABA and glycine work together to fine-tune how nerve cells in the hearing part of our brain respond to sounds.

Featured Image