Review Question - QID 215130

A 25-year-old man is transported to the emergency department after he caused a disturbance inside a car dealership. When asked about what happened, he says that he went to the dealership because he has a rare car that he wanted to sell and is secretly friends with the dealership owner. Past medical and social history is significant for multiple substance use disorder and homelessness. He is not currently taking any medications. On physical exam, he has horizontal nystagmus and is unable to complete finger-to-nose coordination or rapidly alternating movements. Administration of the most appropriate treatment for this patient's symptoms can be measured by increased activity of a protein located in which of the following cell areas?