Scientists from Japan's Natural Science Research Institute have developed an innovative deep brain imaging technique for studying a key brainstem structure in the brain - the solitary nucleus (NTS). This achievement has opened a new window for the study of "brain body mind" interaction, providing a powerful tool for investigating the complex connections between the brain and body, and also building a bridge for the translation of basic neuroscience research into clinical practice. The relevant paper was published in the latest issue of Cell Reporting Methods. NTS is an important hub for communication between the brain and body organs through the vagus nerve, which is crucial for emotional regulation and overall mental health. However, previous traditional imaging methods were unable to comprehensively observe it in live animals. The reason why NTS is difficult to study is because it is located in the deep region below the cerebellum. The old method had to remove the cerebellum in order to approach NTS, but the cerebellum is also an important center for motor coordination and is believed to be involved in emotional regulation. Therefore, the scientific community needs a new method that can preserve cerebellar function while observing NTS. This time, the team introduced a new real-time NTS imaging technology called "D-PSCAN" (imaging of cerebellar brainstem structure and neural circuits based on biprism). This technology can visualize the NTS neural activity of living experimental subjects with high resolution and minimally invasive techniques without interfering with cerebellar function. The core of this technology lies in the precise implantation of a device consisting of two miniature prisms between the cerebellum and brainstem, thereby achieving broad and clear visual coverage of the NTS. The team tested the response of NTS to vagus nerve electrical stimulation. The vagus nerve is responsible for transmitting signals from internal organs to the NTS. They found that specific intensities of vagus nerve electrical stimulation can activate neurons in the NTS, and different stimulation parameters can lead to different neural response patterns, including excitatory enhancement or inhibitory effects. At present, vagus nerve electrical stimulation has been used to treat drug-resistant epilepsy, and its application in mental and neurological disorders such as depression is also being explored. This time, it is expected to optimize the relevant treatment parameters. The team also studied the functional performance of NTS under more natural conditions: when mice consume food, hormones released from the gut can trigger neural activity in NTS, indicating that NTS plays an important role in sensing and integrating signals from within the body. A deeper understanding of this mechanism can help develop new therapies for mental and neurological disorders, promoting human mental health and overall well-being. (New Society)