The purpose of this study is to determine the effects of two tricyclic antidepressant agents (TCAs), amitriptyline and desipramine, on gastric emptying and gastric accommodation using a newly developed scintigraphic test that simultaneously measures both gastric emptying and gastric volume (accommodation). These two tricyclic antidepressant agents are commonly used at low doses to treat patients with refractory functional dyspepsia.