Lack of sleep as a child leads to "social fear" when growing up... New research reveals the neural mechanism by which adolescents' lack of sleep affects social behavior

▎WuXi AppTec Content Team Editor Sleep takes up almost one-third of one's li.
It is conceivable that adequate sleep must be of great significance to li.
Not getting enough sleep can sometimes quickly manifest problems such as headaches, fatigue, and difficulty concentrati.
If you lack sleep for a long time, many physiological indicators will also light up red lights, which are closely related to the increased risk of a series of diseases such as obesity, dementia, and canc.
However, there are some effects of sleep deprivation that may be less obvious, but can quietly affect life years lat.
You may not think that social barriers in adulthood may also be the hidden dangers of lack of sleep in adolescen.
Recently, a research paper published in "Nature Neuroscience" (Nature Neuroscience) revealed through mouse experiments that disturbed sleep during adolescence directly affects social behavior in adulthood, and social deficits appear when interacting with unfamiliar mi.
Conversely, managing to supplement sleep during adolescence could help autistic mice drastically improve their social impairments in adultho.
How long a person needs to sleep each day shows significant changes with age: in infancy, most of the day is spent sleeping; with continuous growth and development, our need for sleep continues to decrease until In adulthood, sleep duration usually stabilizes at 7-8 hours per d.
"Compared to the function of sleep in the adult individual, we still know very little about the role of sleep during development," said Wenjie Bian, .

, lead author of the study from Stanford Universi.
During adolescent development, sleep may play a special ro.
"▲Adolescents need 8 to 10 hours of sleep per night, but in recent years, meta-analyses from many countries have shown that more than half of the adolescents are sleep deprived (Image source: 123RF) In order to answer how sleep in adolescence affects brain function, researchers A set of experiments was designed in which mice were allowed to sleep 4 hours less each day for 5 consecutive days during their teenage years (35 to 42 days after birt.
As a result, these mice, as adults, were similar to control mice that slept normal.
In contrast, social behavior is abnorm.
Under normal circumstances, young mice who have just grown up are just like young people who have just entered the social fie.
They are naturally curious about unfamiliar mi.
The mice were also more interested in, and actively socialized with, unfamiliar mice when they were mi.
However, the mice that experienced sleep disturbance during the teenage years lost a strong interest in socializing with the unfamiliar mi.
Using the researchers' science In terms of terms, they lost their preference for social novel.
▲Behavioral tests showed that mice that were once sleep-deprived in adolescence lost a strong interest in socializing with unfamiliar mice in adulthood (Image source: Reference [1]) and When the researchers performed the same sleep disturbance in the mice at a slightly older age (42 to 49 days after birth), they found a similar loss of preference, but the effect was less pronounc.
Later, after adulthood, the same The degree of sleep deprivation did not cause changes in social behavi.
These results suggest that sleep in adolescence has a special function for later social behavi.
So why is sleep in adolescence so special? In further exploration of the neural circuit level After the change, the researchers found that dopaminergic neurons in the ventral tegmental area (VTA) of the midbrain play an important role in this proce.
▲The author's hand-painted schematic diagram: When you are a teenager, you get enough sleep, and you can "talk and laugh" with unfamiliar mice when you grow up (Image source: provided by the research author) Specifically, the dopaminergic neurons of the VTA and the nucleus accumbens ( NAc) and the prefrontal cortex (PFC) make up the midbrain-cortical/limbic system pathway and play important roles in motivation, addiction, and reward-related behaviors; while in social animals—whether humans or mice, social Stimulation is generally regarded as a "reward", so the VTA also regulates social behavi.
Using cutting-edge optical fiber recording technology (fiber photometry), combined with a novel dopamine fluorescent probe (GRABDA sensor) and other methods, the researchers recorded the electrical activity of VTA dopaminergic neurons in the brain of mice in real time during social behavi.
, and directly monitor dopamine relea.
The results consistently showed that when the mice in the control group first met an unfamiliar partner, both the neuronal response of the VTA and the release of dopamine in the NAc had the greatest response; with the increase of familiarity, the neural response gradually decreased; The social stimuli—new, unfamiliar mice—received sharp respons.
But in teenage sleep-deprived mice, this pattern of neural responses disappeared! Neither VTA neurons nor NAc dopamine release responded to the new, unfamiliar mi.
Not only that, projections from the VTA to the NAc were abnormally enhanced in the brains of these mice, suggesting that sleep disturbance during adolescence may have affected the wiring and refinement of dopaminergic neurons during development, leading to dopaminergic dopaminergic neurons in adultho.
The system cannot respond in a timely and effective manner to emerging social stimu.
Subsequent studies pointed out that VTA dopamine neurons have different states in different stages of sleep, and the normal sleep/wake cycle in adolescence helps to maintain the excitability level of VTA neurons within a reasonable range, preventing its development during developme.

In the process of being overexcited, normal dopaminergic circuit systems and social behaviors are form.
Image credit: 123RF The study also explored the possibility that increased sleep during adolescence could improve social behavioral disorders in adultho.

"In a variety of neurodevelopmental disorders, such as autism and schizophrenia, the proportion of sleep disorders is as high as 50% to 80%, especially in adolescent patien.

More studies have found that in autistic patients, sleep disorders are associated with There was a significant positive correlation with the severity of social impairment, " the researchers not.

Using a mouse model with a genetic mutation that causes autism, the researchers found that drugs that increase non-rapid eye movement (NREM) sleep in adolescence or optogenetically selectively increase the slow-wave component of the cortex (NREM sleep) One of the important features), or inhibiting the electrical activity level of the VTA by chemical genetics, can greatly improve the social impairment of these autistic mice, so that they no longer show "social fear" when facing unfamiliar peers in adulthood , but exhibit relatively normal social novelty preference.

Although these results are from mouse experiments, and human social behavior is more complex, the relationship between changes in social behavior and sleep needs more research, but these results are enough to make us more aware of the importance of sleep, especially for the brain For adolescents who are in their developmental stag.

▲.

Bian Wenjie is the first author and co-corresponding author of this study (Image source: provided by the author of the study) "Our findings reveal a completely new function and circuit mechanism of sleep in brain development during adolescence , expands our understanding of sleep and social behavio.

” .

Wenjie Bian pointed out, “For adolescents who are in the stage of continuous brain and body development, personality and various behavioral habits, ensuring sufficient quality sleep every d.

It may be particularly important; and for those young people who are unfortunately suffering from neurodevelopmental diseases such as autism and schizophrenia, maybe we can change our thinking and try to improve sleep to alleviate or prevent the symptoms of social disorders that may worsen in the futu.

improve their quality of li.

"Reference: [1] Wen-Jie Bian et .

, (2022) Adolescent sleep shapes social novelty preference in mi.

Nature Neuroscien.

Doi: https://d.

org/11038/s41593-022-01076-8