The expression ‘sleeping like a baby’ refers to the good quality of sleep that little ones enjoy, but what happens if a baby doesn’t sleep well or their rest is frequently interrupted? Well, it seems that a sleep deficit in childhood has a powerful influence on key aspects of brain development and increases the risk of developing autism spectrum disorders (ASD).
That is the conclusion reached by a group of researchers from the laboratory of Graham Diering, assistant professor of cell biology and physiology at the University of North Carolina (UNC) School of Medicine, after conducting a study led by Sean Gay. , graduate student in the aforementioned laboratory.
It was already known that sleep deprivation in adults causes long-term physical and mental health problems, such as a weakened immune system, weight gain, depression or an increased risk of dementia, among others. But, in the case of children, sleep loss can have very serious consequences that determine their development, according to results published in the Proceedings of the National Academy of Sciences.
How sleep loss influences autism risk
Sleep plays a fundamental role from the moment we are born. During childhood, our brain continues to form connections at the endings of neurons, called synapses, which are essential for learning, attention, working memory and long-term memory. Sleep allows these neurons to develop and connect with each other, laying the foundation for brain functions for life.
If this delicate process is disrupted, whether by constant waking up or separation anxiety, it could have a lasting impact on the brain and behavior. The new study helps better understand how sleep loss in childhood affects brain development and how this may increase the risk of developing ASD.
“Infants and children are more vulnerable to the negative effects of sleep disruption and sleep loss may interact negatively with the underlying genetic risk for autism spectrum disorder.”
“The unique effects of sleep deprivation during development are largely unexplored,” Diering explained in a note published at UNC. “Our data shows that infants and children are more vulnerable to the negative effects of sleep disruption. “We also found that sleep loss during this crucial period may negatively interact with the underlying genetic risk for autism spectrum disorder.”
Sleep disturbances are an important early indicator of problems in brain growth and other neurodevelopmental disorders, such as ASD, attention deficit hyperactivity disorder (ADHD), and intellectual disability. More than 80% of people with ASD have sleep disturbances, although it is unknown if these are a cause or consequence of ASD.
A study on sleep compensation
Diering has long been researching how sleep strengthens synapses over time – a process called synaptic plasticity – and how lack of sleep contributes to cognitive and neurodegenerative disorders. If the relationship between sleep and ASD were better understood, they could be diagnosed earlier and scientists could develop new treatment strategies.
In 2022, Diering and his colleagues decided to analyze whether sleep disruption in childhood could interact with genetic risk for ASD and lead to lasting changes in adult behavior. Using mouse models, they found that sleep disruption during the third week of life (equivalent to 1-2 years in humans) caused long-lasting deficits in social behavior in male mice vulnerable to ASD.
To delve deeper into these findings, they studied how adult and developing mice compensate for sleep loss. Using sensors in a controlled environment, they tracked the rodents’ movements and breathing to record their wake and sleep states and were able to show that when the adult mice lost a significant amount of sleep, they compensated by increasing sleep during usual active hours, a phenomenon known as “sleep rebound.”
However, young mice did not show this ability, confirming the hypothesis that they are more susceptible to the detrimental effects of sleep deprivation. They also noted that sleep deprivation in young mice completely impaired their performance on learning memory tasks, while adults were more resilient.
They then examined how sleep and lack of sleep influence neuronal synapses, which facilitate communication between neurons and are essential for the formation and storage of memory. They performed advanced molecular analyzes and found that sleep deprivation in young mice, but not in adults, significantly affected synapse formation, an essential aspect of brain development.
An ongoing goal of the lab, driven by the molecular work of this study, is to develop sleep-based medications for children. Instead of acting as sedatives, they seek to create a drug that can act on synapses to restore sleep function without altering sleep behavior itself.
“Development is a process that cannot be repeated,” Diering said. “Sleep is important throughout life and especially in development. Understanding this now will help us put more emphasis on sleep problems in ASD and could open an important therapeutic avenue to treat ASD and other developmental conditions,” concludes the researcher.
