To understand how ketamine works, you need to know how it affects the brain. The therapeutic effects of ketamine come down to these brain changes, which are diverse and multi leveled.
At the level of neurotransmitters, we find that ketamine changes the levels of glutamate.
Glutamate is an excitatory neurotransmitter. It is in a balanced state, or “homeostasis,” with GABA (gamma-Aminobutyric acid,) which is an inhibitory neurotransmitter.
Glutamate is a chemical that has links to major depressive disorder (MDD). Ketamine is an antagonist of the NMDA receptor, a type of receptor for glutamate.
The drug actually blocks these receptors, which then produces an increase in levels of glutamate. The burst of glutamate is brief, correlating with how long the dissociative effects of ketamine last.
Synapses are the small pockets of space between two cells (and also can mean between nerve cell and a gland or muscle cell.)
This allows cells to pass electrical or chemical signals to each other. This is how cells communicate messages. Synapses also allow neurons to form circuits within the brain.
– Ketamine enhances neural responses to positive emotion in the right caudate in patients with depression. After ketamine, there is greater connectivity to positive emotions.