Imaging Study Provides Insights into Memory Functions of the Aging Brain

Researchers in Europe have used PET and MRI brain imaging to show that there is a link between the long-term episodic memory function of the brain and dopamine D2 receptors.

Episodic memory functions often become degraded as a result of dementia, and age, and the research could help explain why only some people suffer from memory impairment. The results of the study were published in the July 12, 2016, issue of the journal Proceedings of the National Academy of Sciences (PNAS).

The researchers from the Umeå University (Umeå, Sweden) used Positron Emission Tomography (PET) and Magnetic Resonance Imaging (MRI) brain-imaging for the study. The researchers then used statistical analyses, and post processing, including 3D imaging to study the mechanisms behind memory degradation that occurs during aging.

The researchers recruited 181 healthy people aged between 64 and 68, for the study. All participants also took part in memory and processing speed tests, coupled with measurements of the different parts of the brain using an MRI assessment. During the study, the researchers used a PET camera to examine differences in the D2 system of the brains of the individuals.

The results showed that the D2 system was positively linked to episodic memory. The system was not linked to processing speed or working memory. The researchers were also able to uncover how the D2 system was affecting hippocampus functions.

Director at the Umeå Centre for Functional Brain Imaging, professor Lars Nyberg, said, "Our results link the dopamine D2 receptor to long-term episodic memory, likely via hippocampus functioning. Episodic memory is often reduced with age and in people with dementia. Hence, impairment of the dopamine system are important to consider when attempting to understand the bases of impaired cognitive abilities due to aging."

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