EXELON AND REMINYL

Research: Current Research, Cholinesterase Inhibitor Drugs: Aricept, Exelon and ReminylThese drugs are cholinesterase inhibitors. They help preserve the ability of sick nerve endings to transmit the nerve messages to the next cell in the chain. The first of these drugs appeared in 1986, but wasn't consistently effective until ten years later when along came the new generation of cholinesterase inhibitors, and their success was rapidly recognized. How they work makes a fascinating story. Nerve messages, or impulses, travel along nerve fibres by an electrical mechanism, but the electricity is inadequate to cross the junctions between the nerve and the next cell. Nature invented a mechanism to deal with this problem: each arriving impulse releases a tiny blip of a chemical called a neurotransmitter, which diffuses very rapidly across the junction to stimulate the next cell. For Alzheimer's disease the most important neurotransmitter is acetylcholine, the one used by the nerve cells in the thinking and memory-making parts of the brain. After the acetylcholine has carried the message across the junction it's critical that it be eliminated immediately, otherwise it would keep on stimulating the downstream cell. This could be disastrous, leading to seizures for example. Nature dealt with this potential danger by ensuring that the acetylcholine is destroyed immediately after it's delivered the message, and this is done by an enzyme called cholinesterase.This story has to start by talking about another neurotransmitter called glutamate. Unlike acetylcholine, glutamate is not destroyed by an enzyme after doing its job of conveying the message across the junctions between nerve cells. Instead it's taken back up into the nerve endings from which it was released, or in other words, it's recycled.