What marsupials can teach you about human brain development

Early developmental features of the human brain may be more similar to marsupial brains than you might think. That’s what a new study from the University of Queensland in Australia points out.

The researchers say their findings could lead to a better understanding of brain patterns associated with neurodevelopmental conditions such as autism spectrum disorder (ASD). The findings were published in the journal Proceedings of the National Academy of Sciences (PNAS).

“Marsupials are mammals born at extremely early stages – the equivalent of mid-gestation in human terms,” said Suárez. “Most marsupial brain development occurs after birth, inside the mother’s pouch,” details lead author Rodrigo Suárez of the Queensland Brain Institute and the university’s School of Biomedical Sciences.

The expert explains that the analysis made it possible to study patterns of neural activity in the Australian native species, the fat-tailed Dunnart, which led to discoveries of similarities to the human brain being formed in the womb.

The researchers used light indicators to record the electrical activity of neurons in the marsupials. “We followed the initiation and maturation of complex activity patterns, using advanced microscopy to read how developing brain cells communicate for the first time,” said Suárez.

He details that distinct patterns were identified early on, indicating not only that neural activity begins before sensory experience, but that unique electrical characteristics in newborn cells may be crucial for establishing healthy brain connections.

“Likewise, subtle defects in these patterns can lead to neurodevelopmental conditions like ASD,” he adds.

According to the researcher, it is well established that human babies respond to stimulation well before birth. “But exactly when, where and how electrical activity starts in the developing brain remains largely unknown,” he said.

Suárez says this is mainly because only mammals have evolved a cerebral cortex – the wrinkled surface of our brains that controls sensory, motor and cognitive tasks – and most experimental models cannot survive at such early stages outside the womb.

The study of marsupials can help researchers advance knowledge about the evolution of the human brain. “These findings highlight early brain development processes that emerged millions of years ago and are ongoing with little change, likely influencing the evolution and diversification of the cerebral cortex.”