細胞内アセチルコリン受容体によるシナプス伝達の制御とストレス

抄録

Acetylcholine is crucial for regulation of synaptic transmission in the hippocampus and the cortex, the center of learning and memory. Released acetylcholine from cholinergic terminals is thought to act on muscarinic and nicotinic acetylcholine receptors on plasma membrane, and is subsequently hydrolyzed by cholinesterase. Previous experiments by our group have shown that muscarinic acetylcholine receptor subtype M1 (M1-mAChR) in the brain is highly distributed on intracellular organelles of neurons, such as endoplasmic reticulum and Golgi apparatus, and activates signaling cascades distinct from those of plasma membrane receptor. The intracellular M1-mAChRs is activated by endogenous acetylcholine following its uptake via a putative transport system without degradation, which facilitates long-term potentiation in the hippocampal CA1 synapses. In addition, the cholinergic synaptic regulation through intracellular M1-mAChR in the hippocampus disappeared after chronic physical stress. In this symposium, we demonstrate the function of intracellular M1-mAChR in the brain and discuss about possible contribution to stress and neuropsychiatric disorder.