Muscarinic receptors have pivotal role in human body physiology. Understanding them at biomolecualr level provided targets for many disorders. Understanding muscarinic interactions with cholinesterase inhibitors will provide the novel therapeutic platform for better treatment with less adverse effects. Muscarinic receptors play a pivotal role in treating the chronic obstructive pulmonary disorders, over active bladder, cardiovascular disorders, neurological disorders such as Alzheimer diseases, organophosphate poisonings. etc. So with that curiosity this work have been performed and the findings were the key and new. There is a receptor cross talk between muscarinic M2 and M3 receptors to modulate the endogenous release of Ach.