In treating depression, it was theorized that substances that could enhance norepinephrine transmission, such as tricyclic antidepressants (TCA), could diminish the symptoms of clinical depression [REF].
Richard Kattau in the Rathbun laboratory tested the newly created drugs within the series of PPAs for their ability to reverse apomorphine-induced hypothermia in mice, a test in which the TCAs were active antagonists [REF].