Dopamine and behavioral control across the adult lifespan 

PI: Marc Guitart-Masip,

Our cognitive skills ‒ our ability to remember, think, and make decisions ‒ decline as we age. One reason is loss of dopamine, a brain neurotransmitter (chemical messenger). The main purpose of this project is to illuminate the relationship between loss of dopamine and age-related impairments in cognitive skills.

The project consists of an experiment in which we compare older and younger people. We will begin by using a technique known as positron emission tomography (PET) to measure the incidence of dopamine receptors in various parts of the brain. Next, we will use functional magnetic resonance imaging (fMRI) to examine participants’ brain activity during behavioral experiments in which they decide between different options for optimizing profits. FMRI identifies the regions of the brain that activate when the decisions are made. Finally, we will compare the relationship between dopamine receptor incidence, behavior, and brain activity in younger and older participants.

One aim of the project is to better understand how different aspects of dopamine function that occur in different parts of the brain are related with each other and how these relationships change when we age. We also want to separate age-related changes in cognitive skills that are caused by loss of dopamine from changes that have other causes. Such knowledge may influence the development of new therapies to counteract cognitive problems in aging and to prevent the occurrence of such problems. Furthermore, a better understanding of the workings of the dopamine system in healthy participants will help researchers design projects to improve our understanding of psychiatric conditions associated with changes in this system, such as schizophrenia, addiction, ADHD, and depression. This, in turn, should facilitate the design of better diagnostic and therapeutic tools for people with these disorders.

The project is funded by a grant from the Swedish Research Council.