Research into how the heart communicates is yielding some fascinating insights. A recent study with mice has shown that the heart’s cells receive signals from the nervous system, but then the heart initiates its own way of passing on signals to other heart cells. The results could lead to novel ways to study the mechanisms of heart failure – where the system that speeds up and slows down the heart gets out of whack and results in the heart’s being unable to pump enough blood to the muscles.
What heart cells use to send messages to other heart cells is the neurotransmitter acetylcholine (ACh). The study used mice whose heart cells only had been engineered not to release ACh. Their heart rates remained normal at rest but went much higher than usual rates during exercise and their hearts took much longer to return to normal after exercise. “The results suggest the heart cell derived ACh may boost parasympathetic signaling to counterbalance sympathetic activity.”
The researcher thinks this heart-critical non-neuronal source of ACh might also play a role in other organs. This study was supported by the Heart and Stroke Foundation of Ontario, the Canadian Institutes of Health Research and the Canada Foundation for Innovation.