A recent study conducted by the University of Queensland has discovered that marsupials exhibit features of early human brain development, offering potential insights into neurodevelopmental conditions such as autism spectrum disorder (ASD).
Lead author Dr Rodrigo Suárez, from UQ’s Queensland Brain Institute and School of Biomedical Sciences, explained that marsupials are born at extremely early stages, equivalent to mid-gestation in humans.
Since most of their brain development occurs postnatally inside the mother’s pouch, researchers were able to study neural activity patterns in the Australian native fat-tailed dunnart, which showed similarities to the human brain in utero.
By using light indicators to record the electrical activity of neurons in marsupial joeys, the research team observed the onset and maturation of complex activity patterns. Advanced microscopy techniques enabled them to understand how the communication between developing brain cells first occurs.
The researchers discovered distinct patterns indicating that neural activity begins before sensory experience and that specific electrical features in newborn cells may play a crucial role in establishing healthy brain connections. Conversely, subtle defects in these patterns could contribute to neurodevelopmental conditions such as ASD.
Dr Suárez noted that while it is widely known that human babies respond to stimulation before birth, the precise timing, location, and initiation of electrical activity in the developing brain have remained largely unknown.
This knowledge gap arises from the fact that only mammals possess a cerebral cortex, the folded outer layer of the brain responsible for sensory-motor and cognitive functions, and most experimental models cannot survive outside the uterus at such early stages.
Studying marsupials provides researchers with an opportunity to delve further back into brain evolution. The findings shed light on early brain development processes that emerged millions of years ago and have remained relatively unchanged, influencing the evolution and diversification of the cerebral cortex.
The study was published in the Proceedings of the National Academy of Sciences (USA), emphasising the significance of these findings in understanding the parallels between marsupial and human brain development.