When making first reference in body text and cutlines to any of the departments, programs, centers or units in Arts & Sciences, in Arts & Sciences is to be included: The lecture is sponsored by the Department of Psychological & Brain Sciences in Arts & Sciences.
Always use an ampersand — never and.
When possible, use both in Arts & Sciences, all in Arts & Sciences, or similar language to eliminate the need to write in Arts & Sciences multiple times: The lecture is sponsored by the departments of Psychological & Brain Sciences, Biology and Anthropology, all in Arts & Sciences.
See school.