Johannes Kohl has been named the 2018 Grand Prize winner of The Eppendorf & Science Prize for Neurobiology, for research that makes sense of how a cluster of neurons controls parenting behavior in mice. Kohl's prize-winning essay highlights the function of a small population of neurons located in the medial preoptic area (MPOA) of the hypothalamus (a portion of the brain that shares common features with other vertebrates). Kohl zeroed in on MPOA neurons bearing a molecule called Galanin (MPOAGal), which were previously identified to be critical for parental behavior in both males and females. Using mouse models and imaging techniques (to record the activity of specific neurons in rodents), Kohl investigated the processes underlying the MPOA neurons' ability to control a complex behavior. He studied the neuronal pools that were crucial for parental behavior, by identifying the pools that were most highly activated when mice interacted with their pups. Kohl determined that while the entire MPOAGal population became active during all aspects of parenting, surprisingly, individual pools were activated during discrete parenting events, suggesting that they control specific components of parenting. The pools included those projecting to brain regions such as the periaqueductal gray (PAG, which is involved in motor control), the ventral tegmental area (VTA, an area implicated in the drug and natural reward circuitry) and the medial amygdala (MeA, known to play a role in innate emotional behaviors). Kohl said that while "it is too early to know whether these findings are directly applicable to humans - where behavior is considerably more complex and subject to many additional social or cultural influences, for example," the results represent significant progress in uncovering how a social behavior is wired into the brain. In humans, parental care is affected by stress and mental illnesses such as postpartum depression and anxiety, which together affect almost 20% of mothers in the U.S. Addressing how physiological states and environmental factors interact with these circuits might therefore open new avenues for treatment of common mental illnesses. Finalists for the prize were Tomasz Nowakowski, for his essay "Building blocks of the human brain," and Talia Lerner, for her essay "The effortless custody of automatism." Coverage of the 2018 prize winner and finalists will be available on 12 October at http://www.