Ketamine:

Ketamine is a drug that helps form new synaptic pathways or neural connections. It’s an NMDA receptor antagonist, binding with NMDA receptors to block glutamate binding on the cell membrane (oversupply is a cause of Alzheimer’s). Ketamine also affects synaptic pathways (neural connections in the brain), which is possibly how it helps form new neural connections. Ketamine is also is used recreationally in other countries because of its hallucinogenic/euphoric properties. It’s classified as a dissociative drug and is extremely dangerous when unregulated.

• NMDA receptors: Glutamate is a chemical messenger (neurotransmitter) carrying signals across the brain. When passing information between neurons, glutamate attaches itself to a new cell by using an NMDA receptor (N-methyl-D-aspartate) and passes calcium into the cell—carrying electrochemical signals to the last step (a new cell along the chain). This is important for learning and memory.
• NMDA receptor antagonists: Drugs work to “antagonize” or prevent the brain from an overload of glutamate—by making it harder for glutamate to dock onto new cells. They’re used as anesthetics for humans and animals by creating a dissociative state. [Glutamate overload causes Alzheimer’s. The drugs make it harder for glutamate to “dock” onto new cell, slowing the disease’s progression.]