Researchers identify molecular features of brain regions associated with high levels of education in the elderly
A study led by a team from the Institute of Neurosciences of the UBidentified greater cortical thickness in the frontal lobe in a group of old people with high levels of education (15 or more years of education). Afterwards, the study of the molecular architecture of these regions revealed these areas feature a relative overexpression of gene families involved in synaptic transmission and in the activation of the immune response. Results provide new data on humans regarding potential molecular mechanisms that may explain how high levels of education are associated with preserved cognitive function in the elderly.
The tota number of years of attained education is the most common proxy measure of cognitive reserve, a Psychological construct that reflects the capacity of the adult brain to counteract or minimize the cognitive impact of the typical effects of ageing (i.e. brain atrophy) and even of the initial stages of neurodegenerative conditions (such as Alzheimer’s disease).
In a study led by Dr. David Bartrés-Faz, Associate Professor at the Faculty of Medicine and Health Sciences and researcher at the Institute of Neurosciences of the UB and the August Pi i Sunyer Biomedical Research Institute (IDIBAPS), together with the team led by Dr. Michel J. Grothe, from the German Center for Neurodegenerative Diseases (DZNE) and published in The Journal of Neuroscience, the researchers, using magnetic resonance data, analysed the brain regions that differ in cortical thickness among older adults with high years of attained education (15 or more) compared to a group of lesser educated individuals.
“This analysis suggested the group of people with more years of education exhibited greater cortical thickness in the frontal lobe, particularly in the prefrontal areas of the anterior cingulate cortex and the orbital cortex”,
says David Bartrés-Faz.
In a second part of the study, researchers analysed whether these regions were featured, at a molecular level, by a different genetic expression profile than the other areas in the brain. To do so, researchers used data from the Allen Institute Human Brain Atlas, which contains information of the cerebral cortex’ human transcriptome. “What we saw –notes Bartrés-Faz is that, compared to the other regions of the cerebral cortex, the areas where people with higher levels of education show a major cortical thickness are characterized by an overexpression of gene families involved in synaptic transmission-, and therefore, in brain plasticity mechanisms, as well as in gene families involved in immune responses”.
“The results are relevant because they reflect -for the first time- the molecular features of brain areas in humans that vary in thickness depending on the education these people received. More specifically, this data is of interest because it conciliates previous studies suggesting that education modulates brain plasticity mechanisms. According to Bartrés-Faz, “the identified molecular evidence regarding the overexpression of gene families linked to neurotransmission systems suggest this effect”, says the researcher.
Previous studies on neuroimaging had already shown that prefrontal regions such as the anterior cingulate and orbital cortex exhibit increased metabolism and functional connectivity in old people with high levels of cognitive reserve. These results had been understood, as reflecting greater neural efficiency or higher compensatory capacity to counteract brain atrophy and damage in these elders. The new study is compatible with these interpretations, while providing new directions for future molecular studies on brain health in ageing.
The study has been carried out analysing neuroimaging data of 122 cognitively normal older adults (87 women and 35 men, average age of 68.2), including participants from the study Walnuts and Healthy Ageing (WAHA), coordinated by Dr. Emili Ros, from the Service of Endocrinology and Nutrition at Hospital Clinic de Barcelona-IDIBAPS and the Physiopathology of Obesity and Nutrition Networking Biomedical Research Centre (CIBERobn).
David Bartrés-Faz, Gabriel González-Escamilla, Lídia Vaqué-Alcázar, Kilian Abellaneda-Pérez, Cinta Valls-Pedret, Emilio Ros, Michel J. Grothe. “Characterizing the molecular architecture of cortical regions associated with high educational attainment in older individuals”. The Journal of Neuroscience, 8th April 2019.DOI:10.1523/jneurosci.2370-18.2019