A new, needle-thin brain implant has been successfully tested. This flexible implant is capable of performing three functions simultaneously. It allows for recording neural activity, delivering drugs, and stimulating multiple brain regions. All these functions are carried out using a single fiber. Following successful tests in mice, it is suggested that this implant could provide scientists with a more precise and less invasive way to study the brain. In the future, it may assist in treating neurological disorders. Epilepsy is an example of such disorders.