...ANAVEX2-73 has an inhibitory constant (ki) lower than 500 nM for all M1–M4 muscarinic acetylcholine receptor subtypes, demonstrating that it acts as a powerful antimuscarinic compound.[2] ....
How may AVXL 2-73 benefit motor impairment of Parkinson's Disease?
Levodopa is a drug to treat Parkinson's disease, but a side effect of long-term use of levodopa is dyskinesia.
"The features of dyskinesia include rapid, involuntary, and uncontrollable movements other than the tremors typical of Parkinson’s. Dyskinesia can present as body swaying, writhing, twisting, squirming, arm flailing, fidgeting, or head bobbing. Dyskinesia initially appears on the side of the body most affected by Parkinson’s. Although it can be localized to one part of the body such as the legs and arms, it can also spread to the torso, head, and neck. In rare circumstances, dyskinesia can also affect speech and respiratory and eye muscles.....
In Parkinson’s, there is a loss of brain cells called dopaminergic neurons that make dopamine; therefore, the level of dopamine in the brain starts to decrease. The purpose of taking levodopa is to temporarily restore the dopamine that is lost. However, since levodopa is intermittently taken over the course of a day, the level of dopamine will rise and fall. These dopamine level fluctuations, in combination with the loss of dopaminergic neurons, are thought to cause dyskinesia. Dyskinesia can occur when the level of levodopa in the body is at a maximum, referred to as peak dose dyskinesia, or when the levels of levodopa are rising or falling, referred to as diphasic dyskinesia."
"Therapies that increase dopamine or activate dopamine receptors, such as levodopa, are currently used to restore motor skills. However, these treatments are not fully effective and their benefits wear off over time. Researchers have thought that a decline in dopamine levels would increase acetylcholine production. Higher levels of acetylcholine are suggested to cause the dyskinesia — uncontrolled, involuntary movements — observed in Parkinson’s patients under long-term dopamine therapy. "
"M4 muscarinic receptors function as inhibitory autoreceptors for acetylcholine. Activation of M4 receptors inhibits acetylcholine release in the striatum. The M2 subtype of acetylcholine receptor functions similarly as an inhibitory autoreceptor to acetylcholine release, albeit functioning actively primarily in the hippocampus and cerebral cortex.........