The group employed various viral tracing methods — infecting receptor - expressing neurons with a virus strain and
watching them spread as they label infected cells with a fluorescent protein — to visualize the
neural circuit downstream of the ESP1 receptor, as well as providing an image of nerve fibers belonging to specific neurons in the brain and synapses relaying impulses from neuron to neuron, to map the anatomical foundation that conveys ESP1
signals in the brain.