Scientists said on Wednesday they have pinpointed a key brain chemical involved in dealing with the sudden loss or long-term separation of a partner.

By Randy Dotinga, HealthDay ReporterHealthDayNews -- In a discovery that could change assumptions in the world of neuroscience, European researchers have found human brains actually change shape while learning a complicated skill such as juggling.Brain scans reveal that gray matter expands in people as they learn how to juggle, then retracts as they fail to practice.