How can donepezil improve communication between nerve cells?

Donepezil is an inhibitor of the enzyme acetylcholinesterase.
Acetylcholine is a neurotransmitter that diffuses across synapses, binds to the acetylcholine receptor and causes sodium ion channels to open. Influx of sodium ions into the neurone causes a new nerve impulse to be released.In normal cells, acetylcholinesterase breaks down acetylcholine to end the signal.
In diseased cells, there are problems with communication between neurones. Because Donepezil inhibits acetylcholinesterase, less acetylcholine is broken down, so more acetylcholine is available to bind to receptors, meaning more sodium ions enter neurons to reach the threshold for an action potential.