Estrogens are known for their role in reproduction, but a new study from Fujita Health University, Japan, reveals that neuroestrogens—estrogens produced in the brain—play a key role in appetite regulation. These brain-made hormones enhance the expression of a hunger-suppressing receptor in the hypothalamus and improve leptin sensitivity. The findings highlight a new biological pathway that could lead to innovative strategies for managing obesity and eating disorders.

A team of biologists and robotic engineers have developed a virtual reality system for fish to decipher how they school. They uncovered the natural ‘control law’ that is used by zebrafish to coordinate behaviour with others, a behavioural algorithm that has been tuned over millennia to facilitate effective collective motion. Since such collective behaviour could be highly advantageous for technological solutions, such as in the control of autonomous vehicles, the scientists then tested its performance with groups of robotic cars, drones and watercraft. They found that the rules of interaction that have evolved in fish are highly effective for robotic control, demonstrating their potential for the control of fleets of robots in the future. The research, published in Science Robotics, was led by scientists at the Cluster of Excellence Collective Behaviour, University of Konstanz, and the Max Planck Institute of Animal Behavior (MPI-AB), Germany, in collaboration with researchers at Eötvös University in Hungary and the Massachusetts Institute of Technology (MIT) in the United States.

In 2013, a sea star wasting syndrome decimated populations of Pisaster along the west coast of North America and along the Monterey Peninsula in California, where this study was conducted. The orange and purple stars have a hungry appetite for mussels in the rocky intertidal. Without the voracious sea stars lurking around, mussel populations exploded, expanding in cover from around five percent to more than 18 percent within three years. In the wake of the sea star die-off, mussels became a major prey surplus for sea otters, revealing a surprising link between the adjacent rocky intertidal and kelp forest ecosystems. The new research into the phenomenon shows how the loss of a keystone predator (Pisaster) in one ecosystem can impart changes to another (sea otters), linking ecosystems.

Researchers led by the University of Cincinnati’s Anna Kruyer and the University of Houston’s Demetrio Labate have published research in the journal Science Advances applying object recognition technology to track changes in brain cell structure and provide new insights into how the brain responds to heroin use, withdrawal and relapse.