Marsupial brain development sheds light on human neurodevelopment

summary: The early stages of human brain development are reflected in the marsupial brain.

The researchers observed that the neural activity patterns of the marsupial Australian fat-tailed dunnart resembled those of the human brain during pregnancy.

These findings may help advance our understanding of neurodevelopmental disorders such as autism spectrum disorders (ASD). Brain development studies in marsupials also provide an unprecedented opportunity to delve into the early stages of brain evolution.

Important facts:

1. Brain development in marsupials occurs mostly after birth and is similar to human brain development in the womb.
2. Researchers used optical indicators to record neuronal electrical activity in marsupial joeys, revealing distinct patterns.
3. This study suggests that subtle defects in these brain activity patterns may contribute to neurodevelopmental conditions such as ASD.

sauce: University of Queensland

Researchers at the University of Queensland have found that features of early human brain development are mimicked in marsupial brains.

Dr. Rodrigo Suarez, lead author of the UQ Queensland Brain Institute and Department of Biomedical Sciences, said the findings could lead to a better understanding of brain patterns and related brain patterns. neurodevelopment Conditions like Autism Spectrum Disorder (ASD).

“Marsupials are very early mammals, the equivalent of the third trimester in humans,” Suarez said.

“Most of the brain development in marsupials occurs in the mother’s pouch after birth.

“Thanks to this, we were able to study the pattern of neural activity in the Australian fat-tailed dunnart, which is endemic to Australia, and found that it resembles the pattern of neural activity in the human brain in utero. ”

In this study, we used optical indicators to record the electrical activity of neurons in marsupial joeys.

“We used advanced microscopy to read how Joey’s developing brain cells initially communicated, tracking the initiation and maturation of complex activity patterns,” Dr. Suarez said. .

“From the outset, there was a clear pattern indicating that not only does neural activity precede sensory experience, but the unique electrical features of neonatal cells may be important for the healthy establishment of brain connections.

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

Suarez said it’s well established that human babies respond to stimuli long before they are born.

“However, little is known about exactly when, where and how electrical activity begins in the developing brain,” he says.

“The main reason is that only mammals have evolved the cerebral cortex (the wrinkled surface of the brain that controls sensory-motor and cognitive tasks), and most models are at such early stages outside the uterus. Because you can’t survive.”

Dr. Suarez said studying marsupials could help researchers trace brain evolution further back.

“These findings highlight an early process in brain development that occurred millions of years ago, has progressed largely unchanged, and likely influences the evolution and diversification of the cerebral cortex. increase.”

About this neurodevelopmental research news

author: Merlet pie
sauce: University of Queensland
contact: Merret Pie – University of Queensland
image: Image credited to Neuroscience News

Original research: closed access.
“Cortical activity emerges in region-specific patterns early in brain developmentWritten by Rodrigo Suarez et al. PNAS

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overview

Cortical activity emerges in region-specific patterns early in brain development

The development of precise neural circuits in the brain requires spontaneous patterns of neural activity before functional maturity. In the rodent cerebral cortex, patchwork and wave patterns of activity develop in the somatosensory and visual regions, respectively, and are present at birth.

However, whether such patterns of activity occur in non-therian mammals, and when and how they occur during development, remain open questions relevant to our understanding of brain formation in health and disease. .

Because it is difficult to study the initiation of patterned cortical activity prenatally in eutherians, here we present an approach in a minimally invasive manner using dunnart in marsupials, in which cortices are formed postnatally. Offers.

We found similar patchwork and traveling waves in the somatosensory and visual cortices of Danat at stage 27 (corresponding to neonatal mice) and generated to determine how these patterns originate and first emerge. examined the early stages of

We found that these patterns of activity emerged region-specifically and continuously in cortical layers of the 24th and 25th stages of the somatosensory and visual cortices (equivalent to embryonic day 16 and 17 in mice, respectively). It was observed that the Thalamic axons establish and innervate the cortex.

Thus, in addition to forming synaptic connections for pre-existing circuits, evolutionarily conserved patterns of neural activity may help regulate other early events in cortical development.