Most of the dementia drugs presently prescribed are cholinesterase inhibitors. To understand how this works in the brain, we have to learn how the neurons function. We have over 100 billion neurons in our brain. Neurons are the message relaying cells. They consist of a cell body that houses the nucleus , mitochondria, and other important systems that keep the neuron alive. Each neuron also has an axon, which is a long “conducting” tube that extends from the cell body. At the end of the axon are the dendrites or “small branches” that extend into the space between the dendrites of the next neuron. The neurons don’t physically touch each other, so how does the electronic message get from one neuron to the other?