Male and female hearts react differently to the stress hormone noradrenaline, according to a recent study published in Science Advances. The research on mice may have ramifications for human heart conditions like arrhythmias and heart failure as well as how various sexes react to certain drugs.

The team built a new type of fluorescence imaging system that allows them to use light to see how a mouse heart responds to hormones and neurotransmitters in real time. The mice were exposed to noradrenaline, also known as norepinephrine. Noradrenaline is both a neurotransmitter and hormone associated with the body's "fight or flight" response. The results reveal that male and female mouse hearts respond uniformly at first after exposure to noradrenaline. However, some areas of the female heart return to normal more quickly than the male heart, which produces differences in the heart's electrical activity.