Minerva is a 65-year-old widow who lost her husband to heart attack two years ago. Minerva has been noted to have become forgetful since her husband's death. She would claim that she misplaced her...

Minerva is a 65-year-old widow who lost her husband to heart attack two years ago. Minerva has been noted to have become forgetful since her husband's death. She would claim that she misplaced her eyeglasses even if she was wearing them. She would forget to close the faucet, put off the gas stove, or close the refrigerator door. In the past several months, she also had declining concentration and her ability to make decisions and solve simple problems in the home. She refuses to eat her food and remains awake most of the time at night. She constantly bewails of a deep feeling of hopelessness that causes her to entertain thoughts of dying. Minerva manifested a bout of severe depression that lasted for about 4 weeks ten years ago following her son's death from suicide. Although her functioning was severely impaired at that time, she gradually regained her energy and motivation to resume to her duties at work. Her older sister had been diagnosed with dementia of the Alzheimer's type at the age of 62. Minerva came from a poor family. Her parents had always emphasized the value of education and her father, in particular, berated her that she would not amount to anything without a college degree. Minerva's determination and hard work earned her the position of a high school principal prior to her retirement. Minerva's husband was a government employee who was characterized as submissive and passive husband. The middle years of their marriage, were marred by frequent marital discord because of her husband's illicit romantic affairs. Minerva's score in the Mini-Mental Status Examination is 18. Question: What neurotransmitters best explains Minerva's most likely diagnosis? Which part of the brain is the main source of this neurotransmitter?