ABSTRACT
Muscarinic receptors are cell-surface proteins belonging to the superfamily of proteins having seven transmembrane domains. Five distinct genes for muscarinic receptors have been cloned and sequenced. Muscarinic receptors are abundant in the brain, where they mediate a variety of important functions including learning and memory. Loss of brain cholinergic function in Alzheimer’s disease (AD) has led to a large effort in developing selective muscarinic agonists as a possible therapeutic treatment for the loss of cognitive function in AD. Several groups have demonstrated muscarinic-mediated activation of phospholipase D in neuronal and nonneuronal tissue. Stimulation of many phosphatidylinositol-coupled neurotransmitter receptors can profoundly influence cell growth. G-protein-coupled receptors mediate an increasingly diverse series of cellular responses. This chapter reviews the varied and cell-specific responses of Muscarinic receptor that explores the possibilities of using currently available muscarinic compounds in new and interesting ways.
