Researchers from Charité – Universitätsmedizin Berlin report new findings on brain development in human newborns. In this section, first author Dr. Stephan Krohn and senior author Prof. Carsten Finke (ECN Member) answer questions about their research findings.

^{The first weeks after birth are characterized by rapid brain development. Therein, the brain only not quickly develops in size (top, MRI recordings), but also in shape (bottom, computational models of left cerebral cortex).}

What was the research question or scientific inquiry behind your study?

The first weeks after birth represent a critical phase of human brain development. While it is well known that the brain shows a rapid increase in size during this time, the development of brain shape remains much less understood. For illustration, the cerebral cortex of prematurely born infants  around 28 weeks of gestational age is still very smooth. Conversely, the cortex of term-born infants (around 40 weeks) is already highly folded, as is also the case in adult brains.

What was the research question or scientific inquiry behind your study?

The first weeks after birth represent a critical phase of human brain development. While it is well known that the brain shows a rapid increase in size during this time, the development of brain shape remains much less understood. For illustration, the cerebral cortex of prematurely born infants  around 28 weeks of gestational age is still very smooth. Conversely, the cortex of term-born infants (around 40 weeks) is already highly folded, as is also the case in adult brains.

How did you approach the topic?

To describe these morphological developments, we studied MRI data of nearly 800 human newborns from the developing Human Connectome Project (dHCP). We applied a novel analysis method that quantifies brain shape using fractal dimensionality (FD), a measure of the brain’s structural complexity. The relatively smooth and regular cerebral cortex of prematurely born infants is reflected by low FD values, whereas the cortex of older infants becomes increasingly irregular with greater folding, resulting in higher FD values.

What did you discover?

Our results show that brain shape is inextricably linked to infant age. In consequence, we were able to predict the age of the newborns from the shape of their brains with high accuracy. In addition, brain shape revealed subtle signatures of premature birth that were not detected by brain size. Interestingly, the brains of genetically related infants were more similar in shape than those of unrelated infants. Moreover, the brains of identical twins who share almost 100% of their genes were even more alike in shape than those of fraternal twins.

Was there anything that surprised you?

We were surprised by the strong link between genetic factors and brain shape. Indeed, this effect was so pronounced that we were able to predict which babies are twin siblings from their MRIs with high accuracy.

What’s your takeaway?

Our work shows that structural complexity analysis captures early-life brain development substantially better than previous measures (e.g., brain volume). Our approach not only facilitates a better understanding of healthy brain development but may also enable the early detection of subtle pathological processes. Not least, the framework provides a new tool to study both age-related and disease-related changes of brain morphology, including neurological and psychiatric disorders. We are currently pursuing this line of research and are seeing some promising first results.

Original Publication: Krohn S et al. Fractal analysis of brain shape formation predicts age and genetic similarity in human newborns. Nat Neurosci 2025 Dec 29. doi: 10.1038/s41593-025-02107-w

Source: Press release

Contact:

Dr. Stephan Krohn & Prof. Dr. Carsten Finke
Department of Neurology with Chair in Experimental Neurology