So how does Ketamine affect the brain and why does this matter? Ketamine has been shown to impact the glutamate and GABA neurotransmitters within our brain. Glutamate is essential for proper brain functioning because it excites and stimulates nerve cells; increasing the likelihood for chemical messages to be transmitted through nerve cells properly. Glutamate is also needed for making another neurotransmitter in our brains called GABA. GABA is known as the "calming" neurotran