The sex of a mouse can determine how their organs can be affected by certain hormones and drugs, according to studies at the University of California.
A team at the University of California, Davis, USA, used fluorescent light imaging (pictured) to study how the hearts of mice respond to the stress hormone noradrenaline, which affects contractions of the heart and is involved in the body’s ‘fight or flight’ survival instinct.
The researchers saw that there was a difference in electrical heart activity, known as ‘repolarisation’, between the sexes, with the hearts of females returning to normal more quickly than males after being given noradrenaline.
Repolarisation refers to how the heart resets between each heartbeat and is closely linked to some types of arrhythmia, or irregular heartbeat.
Meanwhile, in a study at the University of California, San Francisco, researchers observed that only female mice with tauopathies – such as Alzheimer's – survived for longer than male mice when they were given a clinically-approved drug that targets this group of brain diseases.