Cobbers on the Brain

Kids with autism are seen to spend more time on screens than neurotypical kids which results in lower physical activity. Screen use may be related to poor academic and development performance, sleep problems, obesity, social behavior deficits, and attention problems. The AAP (American Academy of Pediatrics) advises caregivers to not expose children under the age of 2 years to any electronic device. Kids between the ages of 2 and 5 years old can be exposed to screens for one hour a day before displaying developmental factors described previously. (1)

Watching television at the age of 12 months can increase the chances of developing autistic symptoms at 2 years old. Early exposure can increase a child’s chances of autistic behavior by 2%. However, caregivers can decrease the chances by 8.9% from daily one on one play. (2)

Screens act as a stimulant equivalent to caffeine, amphetamines, or cocaine for children. Autistic kids are more vulnerable to addiction and negative impacts compared to neurotypical kids. Factors that cause the vulnerability include:

• • Low melatonin and sleep disturbance
    • Screen time causes a disturbance in circadian rhythms by suppressing melatonin. Melatonin regulates hormones, the immune system, and inflammation.
  • Arousal regulation issues
    • Autistic kids experience overstimulation with increased stress response and emotional dysregulation. Screen use can heighten these symptoms.
  • Inflammation of the nervous system
    • The combination of increased stress suppressed melatonin, and sleep disturbances cause inflammation within the nervous system.
  • Decreases healthy frontal lobe development
    • Reduces the connection of white matter and gray matter in the frontal lobe. This affects verbal competence, aggression, and cognitive abilities.
  • Social and communication deficits
    • Autistic kids experience difficulties identifying social cues like reading body language, having low empathy, and having trouble communicating with others. Screen use inhibits the development of these skills. One study found that screen use and background screens can delay language development.
  • Prone to anxiety
    • Screen use is positively correlated with the risk of developing OCD, social anxiety, high arousal, and diminished coping methods. The amygdala can be seen to change functions when exposed to screens which cause serotonin synthesis abnormalities.
  • Sensory and motor integration
    • Kids with autism are prone to have tics that can worsen due to dopamine release from watching screens.
  • Psychiatric disorders
    • Autistic kids are at higher risk of developing ADHD, tics, anxiety, mood disorders, and psychosis. Screen use is seen to increase the display of such disorders. Individuals with psychosis “may experience hallucinations, paranoia, dissociation, and loss of reality-testing” while actively using screens. (3)

Increased screen time is correlated with melanopsin-expressing neurons and decreasing GABA neurotransmitters which cause autistic-like behavior and decreased cognitive and language development. One study found:

• • kids who were exposed to screen for less than 3 hours per day had language delays and a short attention span.
  • kids who were exposed to screens for more than 3 hours per day had language delay, short attention span, and hyperactivity
    • This shows that any duration of screen exposure produces negative effects on children.

The light projected from screens is detected by retinal ganglion cells (RGCs) which signal the thalamic nuclei and visual cortex for image visual function. Melanopsin is used for non-image visual function. It can be found in the suprachiasmatic nucleus (SCN), ventrolateral preoptic area (VLPO), and limbic regions to help balance sleep patterns, cognitive function, and mood.

Neurotransmitter deficiency such as dopamine, acetylcholine, gamma-aminobutyric acid (GABA), and 5-hydroxytryptamine (5-HT) may cause a spectrum of autism. (4)

Neurotypical Brain ~ Brain with Early Onset ~ Autistic Brain

The structure of an autistic brain can be seen to be different compared to a neurotypical brain such as:

• • An enlarged hippocampus
  • They will have a larger amygdala early in life then a smaller amygdala with age compared to a neurotypical brain
  • Smaller tissue in the cerebellum
  • An enlarged head and brain which will shrink prematurely (before mid-20’s)
  • Excess cerebrospinal fluid (5)

Screen use can worsen these factors due to the topics discussed throughout this blog. In conclusion, screen use can heavily negatively impact children with and without autism.

Resources:

1. https://www.frontiersin.org/articles/10.3389/fpsyt.2021.619994/full
2. https://www.medpagetoday.com/neurology/autism/86051
3. https://www.psychologytoday.com/us/blog/mental-wealth/201612/autism-and-screen-time-special-brains-special-risks
4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5849631/
5. https://www.spectrumnews.org/news/brain-structure-changes-in-autism-explained/

What is Autism? 

• Autism (ASD, Autism Spectrum Disorder) is a neurodevelopmental, lifelong condition, with a broad range of conditions characterized by challenges faced by an individual. There are many social skills, repetitive behaviors, speech and nonverbal communication involved with autism. However, each person with autism is unique and may have better or worse skills. 
• An ASD diagnosis now includes other conditions that used to be diagnosed separately, such as Asperger syndrome and pervasive developmental disorder 
• Autism begins to develop during pregnancy and goes through the first few years of a child’s life. If proper nutrition is not available to the mothers during pregnancy, there is an increased risk of having a child with autism. Some nutrients such as zinc, vitamin D, and omega-3 fatty acids have been linked to neuropsychological symptoms. Low zinc has been linked to learning and cognitive impairments, while low vitamin D has been linked to less aid with brain function and axonal connectivity. During the first few years of life, there is abnormal overgrowth in the cerebral, cerebellar, and limbic structures. The overgrowth happens in regions associated with cognition, social and emotional functions, as well as language functions. This overgrowth is then followed by an abnormally slow or stunted growth.

PI3K/ AKT-(PKB)/ mTOR pathway:

• Overactive PI3k/Akt/mTOR pathway in autism. See image to the right for pathway. 
• The dysfunctional PI3K/Akt/mTOR pathway is involved in many processes that are related to the autism spectrum disorder. These include apoptosis, the deficit in social interaction, repetitive behavior, and hyperexcitability.

Symptoms of Autism:

• It is important to understand that many individuals with autism do not experience all of these symptoms, or experience ones that are not listed. Also, individuals with autism who do experience many symptoms do not experience them the same way as others with autism. 
• Symptoms of autism may include: 
• Lack of social communication and interactions 
  • Avoids or cannot maintain eye contact
  • Lack of play, especially social play 
  • Lack of communication with peers 
  • Uses few or no gestures 
  • Difficulty understanding own feelings and the feelings of others
• Restricted or repetitive behaviors or interests 
  • May repeat words or phrases 
  • Uses toys the same way 
  • Focused more on the parts of the object, rather than the object as a whole 
  • Certain routines must be followed daily 
  • Can flap hands, rock body, etc 
• Other possible characteristics of Autism
  • Delayed language, cognitive, and movement skills 
  • Hyperactive, impulsive 
  • Unusual eating and sleeping patterns 
  • Anxiety and excessive worry about situations

Possible Treatments of Autism: 

• Autism has no cure, but there are therapies that may help manage symptoms and allow individuals to be “higher functioning”
• Therapies to help individuals:
  • Occupational therapy 
  • Speech therapy 
  • Pivotal response treatment (PRT)
  • Relationship development intervention (RDI)
• Comorbidities that require medical treatment, not only therapies: 
  • Epilepsy
  • Gastrointestinal problems
  • Sleep disturbances
  • Attention-deficit/hyperactivity disorder
  • Anxiety/ Depression
  • Obsessive-compulsive disorder

Works Cited: 

Autism Speaks Inc. (2021). Treatments for autism. Autism Speaks. Retrieved November 8, 2021, from https://www.autismspeaks.org/treatments-autism.

Centers for Disease Control and Prevention. (2021, March 29). Signs and symptoms of autism spectrum disorders. Centers for Disease Control and Prevention. Retrieved November 8, 2021, from https://www.cdc.gov/ncbddd/autism/signs.html. 

Sharma, A., & Mehan, S. (2021). Targeting PI3K-AKT/mTOR signaling in the prevention of autism. The Journal of Cellular and Molecular Neuroscience.

     Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by neurobiological abnormalities, impaired social skills, repetitive behaviors, and difficulty empathizing with the feelings of others. There is no definitive neurobiological difference that is an indication of ASD, but many areas of the brain have been identified to contribute to the symptoms of ASD.

Cerebral Cortex

     Those with ASD tend to have an overgrowth in the cerebral cortex. This increased volume has effects on the geometry of the brain. All structures in the brain can be affected by an enlarged cerebral cortex because they will have to move to accommodate for the increased volume. Those with ASD can have abnormalities in the folding patterns of the cortical area. Studies have found that the gyri of the frontal cortex in children and adolescents with ASD are significantly enlarged.  The frontal cortex is responsible for managing attention, understanding the feelings of other people, speech and language production, and forming one’s personality. Abnormalities in the frontal cortex associated provide one explanation for the symptoms that are characteristics of ASD.

Cerebellum

The cerebellum of those with ASD has a reduced number of Purkinje cells. Post mortem studies of autistic brains also show an increase in glial cells, reductions of cerebellar nuclei and overall mass, as well as an active inflammatory process within the cerebellum. The decreased number of nuclei within the cerebellum leads to abnormal connectivity with other key areas of the brain. Cognitive deficits, difficulty planning, and impaired working memory are observed in subjects with developmental decreases in the volume of their cerebellum. This video provides interesting information regarding the loss of Purkinje cells and cognitive impairments that are characteristic of ASD. 

The cerebellum is also important for fine motor movements, coordination, and balance. Infants with ASD develop basic motor skills later in life than a neurotypical child. Those with ASD often have repetitive hand movements, impaired gait, and slow manual dexterity. The loss of Purkinje cells is one cause of the motor deficits associated with ASD. The cerebellum sends signals to the prefrontal cortex and cortical motor regions; a loss of cells in the cerebellum leads to a loss of connectivity, signal transduction, and activation in key brain regions. 

Hippocampus

Those with ASD tend to have a larger hippocampus than those who are neurotypical. A study found that young male children with ASD had a 9% larger hippocampal mass compared to the control subjects. Researchers hypothesized this is due to an increased density of interneurons. Although this hippocampus is typically enlarged in those with ASD, another study found that there is a loss of GABAergic neurons in this area. En2 is a gene linked with ASD and mice with this gene knocked out display typical behaviors associated with ASD. Researchers hypothesized that mice with a double En2 (En2-/-) knockout would have defective GABAergic innervation in the hippocampus. 

Results from this study support the researchers’ hypothesis. Mice with the En2-/- phenotype had a reduced number of GABAergic mRNA markers in the hippocampus and cerebral cortex. Abnormalities of the GABAergic neurons within the hippocampus can lead to an unbalanced excitation/inhibition ratio. Loss of these neurons has been shown to lead to impaired maturation of the cerebral and visual cortex. Dysfunction in one area of the brain is rarely isolated to just that area: the brain is the communication center of the body and any deviation from a homeostatic environment can lead to impairments throughout the entirety of the brain.