Decoding the Brainstem: A New Insight into Brain–Body–Mind Interactions

The communication pathways between the brain and the body's organs are essential for regulating emotions and maintaining mental health. Central to this process is the nucleus tractus solitarii (NTS) in the brainstem, which serves as a vital hub connecting neural signals from internal organs via the vagus nerve. Due to its deeply situated position, observing the NTS in living animals has historically been challenging.

Recent advancements have led to the development of a groundbreaking imaging technique called D-PSCAN (Double-Prism-based brainstem imaging under Cerebellar Architecture and Neural circuits), as detailed in a study published in Cell Reports Methods. This innovative method facilitates high-resolution, minimally invasive visualization of neural activity within the NTS in living mice.

D-PSCAN employs a double microprism assembly carefully implanted between the cerebellum and the brainstem, which preserves cerebellar functions while providing an extensive view of the NTS. Neuroscientist Masakazu Agetsuma, the lead researcher, highlighted that the method overcomes the challenge posed by the NTS’s deep location, allowing for detailed study without disrupting cerebellar activity, which is crucial for emotional regulation.

Using D-PSCAN, researchers investigated how the NTS responds to electrical stimulation of the vagus nerve—a major communication route conveying signals from organs to the brain. They found precise thresholds of vagus nerve stimulation required to elicit responses in the NTS. Different stimulation intensities resulted in various neural activity patterns, including both sensitization and inhibitory responses, demonstrating the detailed functional mapping this technique enables.

Vagus nerve stimulation (VNS) is already used in treating drug-resistant epilepsy and is being explored for depression and other neurological conditions. The ability to observe NTS activity in detail could help optimize VNS protocols, enhancing their effectiveness.

Furthermore, the team examined the NTS's response to natural stimuli, such as the gut hormone cholecystokinin, released after eating. They successfully detected neural activity evoked by this hormone, illuminating how brain–body interactions influence emotions and behavior.

Agetsuma emphasized that understanding these interactions could significantly improve treatments for neuropsychiatric disorders and promote general mental well-being. The D-PSCAN method offers a promising tool for advancing research in brain–body–mind interactions, with implications extending into functions such as appetite control, energy management, and gut microbiota regulation.

This study exemplifies how innovative imaging techniques can shed light on complex neural processes, opening new avenues for clinical and basic neuroscience research.

Source: https://medicalxpress.com/news/2025-05-decoding-brainstem-window-brainbodymind-interactions.html