engleski

Development of human gyrification

Early prenatal brain development is characterized by a lissencephalic smooth cortical surface followed by a rapid development of gyrification during last trimester. Currently there is no agreement in the literature what developmental mechanisms contribute most to the process of gyrification. There is an increasing need to resolve this question as MRI bacame recognized as important prenatal diagnostic tool for detecting brain malformations. In this study, we analyzed 17 ex vivo fetal brains ranging from 13-40 post-conception weeks (PCW. All brains were scanned on 3T Siemens scanner. Image processing, corical surface extraction and 3D gyrification index (GI) estimation were conducted using MNI image processing tools. Our results demonstrate an overall increase of GI reaching a peak value at spproximately 40 PCW. Aparallel expansion of the gray surface area showed a similar growth trend. Cortical surface increased more than 10-fold during the perion of 30 to 40 PCW. In conclusion, our data indicate that gyrification index and cortical surface develop in two phases: a slower first phase from 13-30 PCW that we interpret as an ongoing cellular migration and ingrowth of thalamocortical fibers. Second phase, an exponential growth from 32-40 PCW that is probably due to the rapid cortical shaping and cortical fiber ingrowth. Our results support the idea of a relation between increased cortical surface and the process of gyrification. The results of this comprehensive quantitative ex vivo high resolution MRI study of fetal human brain development will serve as a ground work for future in vivo MRI brain developmental studies.

gyrification; magnetic resonance; fetal

Rad je koautorica Lana Vasung kao pozvano predavanje prezentirala i na skupu Seminar in Cognitive Neuroscience, održanom 01.05.2008, Montreal, Kanada