Fear is a basic survival mechanism that allows humans and animals to quickly detect and respond to threats. However, when fear reactions spread to situations where they are no longer relevant, fear generalization occurs. This phenomenon is a central mechanism in several psychiatric conditions, including post-traumatic stress disorder (PTSD) and various anxiety disorders, which together affect around one fifth of the world's population. In this project, we investigate how brain networks create and maintain generalized fear. By combining advanced techniques, brain-wide electrophysiology with thousands of simultaneous neuron signals, two-photon microscopy to image neuronal activity, and molecular methods to map gene expression, we can follow and influence specific neuronal circuits in real time. We will compare how innate and learned fears are processed, and analyze how these are transformed into generalized and maladaptive states. An important part is to investigate whether neuroplastic drugs, such as psilocybin, which is already being tested in clinical trials, can restore balance in the brain network. By identifying which neuronal circuits are altered by treatment, we can identify new biological targets for future therapies. The project has the potential to provide new fundamental knowledge about brain networks, but also to contribute to the development of more precise treatment strategies for PTSD and other anxiety-related disorders.