Tag Archives: brain

Cortical morphology and ancestry

Fan et al 2015_2A recent study published by a large neuroscience team involved in imaging, cognition, and genetics, showed that cortical geometry is correlated with genetic ancestry. Using a sample of US citizens from the PING data, they reconstructed 3D cortical surfaces to obtain information on the morphological variation of the sulci and gyri. To calculate proportions of genetic ancestry they used as reference populations from west Africa, east Asia, a sample of native Americans and a sample of European descendants. The main finding of the study is that cortical folding patterns are strongly related to the genetic ancestry. According to the authors, African ancestry is associated with more posterior and narrower temporal areas. Frontal and occipital surfaces are more projected in Europeans and flatter in Native Americans. Asians have more variability in the temporal and parietal regions. Their results were similar to  Howells’ craniometric analysis. Moreover, all but Europeans display increased morphological variation in the posterolateral-temporal region. Due to these  morphological differences among populations, the authors warn for a possible methodological bias when mixing sample from different geographical origins in imaging studies.

Sofia Pedro


Space oddities

I have previously published a post on the effects of space-travelling in astronauts, particularly concerning eyes and vision. This month, a group of researchers from the UC Irvine have published their study on the effects of space radiation in the brain and cognition. When travelling to Mars, astronauts are exposed to charged particles of the galactic cosmic rays, which can cause cell and tissue damage throughout the body. To find out the consequences of radiation in the brain, the team exposed mice to heavy ion irradiation and then examined their neuronal tissue and task performance. Their results revealed that these particles markedly and persistently change the structure of neurons and neurotransmission, leading to cognitive deficits. Furthermore, the intensity of damage correlates significantly with impairment in task performance, namely new object recognition and location. Thus, this work suggests exposition to space radiation can cause cognitive impairments which might be dangerous during the mission to Mars. Definitely, we are not adapted for the outer space. Yet.

Sofia Pedro