Which muscarinic receptor is associated with increased activity of phospholipase C?

The muscarinic receptor associated with increased activity of phospholipase C is the M1 receptor. When acetylcholine binds to M1 receptors, it activates the Gq protein pathway. This activation leads to the stimulation of phospholipase C, which subsequently produces inositol triphosphate (IP3) and diacylglycerol (DAG). These second messengers play crucial roles in cellular signaling by regulating intracellular calcium release and protein kinase C (PKC) activation, respectively.

The presence of M1 receptors is significant in various tissues, including the central nervous system and gastric parietal cells, where their activation can lead to increased gastric acid secretion and neuronal excitability. Understanding the role of M1 receptors in phospholipase C activation helps illuminate their function in physiological processes and the potential effects of drugs targeting these receptors in various conditions.