The role of cholinergic balance perturbation in neurological diseases.

The maintenance of a balanced cholinergic homeostasis is crucial for the function of the central nervous system, peripheral nervous system and the neuromuscular junction. However, it appears that the cholinergic system is not restricted to neurons and synapses but may also involve immune reactions. In the present review we reassess the role of the cholinergic balance in myasthenia gravis and Alzheimer's disease which for a long time are known to be associated with cholinergic transmission perturbation. We have included neuroinflammation, particularly multiple sclerosis in this group of neurological disorders in light of the relatively new studies involving the immune cholinergic system. In all the aforementioned disorders, treatment with acetylcholinesterase inhibitors can attenuate inflammation. This is performed by increasing the acetylcholine (ACh) concentration near immune cells and making it available for interaction with alpha(7) nicotinic ACh receptor, expressed on these cells. This outcome is additional to the effect of acetylcholinesterase inhibitors on neurons and synapses.