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What Part Of The Brain Does Autism Affect

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Early Screening For Autism

Autism & Pediatric Diseases : What Parts of the Brain Does Autism Affect?

Many children arenât diagnosed with an autism disorder until preschool or even kindergarten, and may miss getting the help they need in the early years. That’s why guidelines call for screening all children at nine months old for delays in basic skills. Special ASD checkups are needed at:

  • 18 months
  • As needed for children with worrisome behaviors or a family history of autism

White Matter: Connecting The Clinical Dots

The second study, also published in Biological Psychiatry, linked changes in the brains white matter growth with autism traits in some children.

The researchers used a type of MRI scan called diffusion-weighted imaging, which allowed them to look at white matter regions, or tracts, in the brain. White matter provides the structural connections in the brain, allowing different regions to communicate with each other.

The study included 125 children with autism and 69 typically developing children who served as controls, between the ages of 2.5 and 7.

The researchers found that the development of the white matter tracts in the brain was linked to changes in autism symptom severity. They observed slower development in children whose symptom severity increased over time, and faster development in those with decreased severity over time.

From a biological standpoint, this emphasizes the role of white matter development in autism and autism symptoms, said Derek Sayre Andrews, postdoctoral scholar at the MIND Institute and lead author on the paper. We hope that in the future, measurements like this can identify children who would benefit from more intensive intervention and serve as a marker to determine the effectiveness of an intervention for a particular child, he said.;

Analysis Of Medication Use

Data on medication use was available for 832 individuals with ASD, of which 214 were categorized as medication users. For each AI that showed a significant effect of diagnosis in the primary analysis, a linear mixed model analysis was performed within-cases only, AI=medication+age+sex+random . Medication was coded as a binary variable .

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Why Autism Strikes Mostly Boys

Why does autism strike four times as many boys as girls? The answer may lie in specific biological shielding mechanisms that operate in girls, but not boys, even when both sexes have the same genetic defects associated with the disorder.

That conclusion leapt from the data in a study led by University of Minnesota researcher Nicola Grissom, Ph.D., an assistant professor of psychology. Published in Molecular Psychiatry, the study opens a door to understanding and one day better treating the disorder.

Researchers have known about the female protective effect in autism spectrum disorders for quite a while, but the reasons why girls might be protected while boys are vulnerable have remained mysterious, Grissom said.

This effect means a boy has a 1-in-42 chance of being diagnosed, but a girl has only a 1-in-189 chance, according to the Centers for Disease Control. Those who do develop the disorder have difficulty in responding to rewards that would otherwise serve as cues that help shape social behavior.

The Corpus Callosum And Brain Communication

Autistically Beautiful : Parts of the Brain Affected by Autism

The brain of children with autism spectrum disorder also has problems with a relevant and significant structure called the corpus callosum.

  • This structure is key to communication between different brain regions.
  • Lynn Paul, a researcher at the California Institute of Technology, saw various alterations in the corpus callosum of autistic children. This can lead to problems in everyday social interactions, inability to grasp various types of information, misinterpretation, and a more rigid mental approach.

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Increased Miscommunication For Autistic Brains

Too many brain connections may be at the root of autism was Science Dailys summary of a study from the Washington University School of Medicine. Researchers found a defective gene that influenced how neurons connect to and communicate with each other. Studies on animals that lacked the gene also showed too many connections existing between those key brain neurons and difficulties with learning and memory.

The findings led the Washington University researchers to suggest that the symptoms of autism may be the result of problems in how cells in the brain communicate with each other specifically that there may be too many synapses in the brains of patients with autism. The senior author of the study explained that instead of more synapses making the brain work better, the higher number results in increased miscommunication between neurons. This leads to impairments with learning, but the mechanisms of this problem arent fully understood.

Brain Structures In Asd

Since neuroimaging approach is one of the few methods that enable to make direct observation of the brain in vivo, Magnetic Resonance Image studies have provided many implications of neurodevelopmental characteristics underlying ASD . Although various results were shown from structural MRI studies over the past decade, there are abnormalities in gray and white matter with some regional brain differences between ASD and typically developing control . Many sMRI studies have investigated volumetric and morphometric brain in order to examine atypical brain anatomy and neurodevelopment in ASD. Reviewing these findings provides insights into the neural substrates and autistic symptoms across the human lifespan.

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Imaging And Image Processing

Autistic patients were anaesthetized prior to scanning. Control subjects were typically scanned during normal sleep, although some remained awake during scanning. All subjects were scanned between 1992 and 1997 on the same 1.5 T magnet using two imaging protocols: a T1-weighted sagittal protocol [TR = 600 ms, TE = 25 ms, 2 NEX , FOV = 16 cm, matrix = 256 × 256, 4 mm slices, no gaps); and a double-echo, T2- and PD-weighted axial protocol . Data were transferred to Silicon Graphics workstations for analysis. Image sets from both subject groups were coded with random numbers and intermixed to ensure blindness of the experimenter to groups.

Daily Living Skills Impairments

How Does Autism Affect the Brain? Part 1 of 2 | SCIENCE CAFE

Medical disorders are common in ASD, with one study finding that only 29% of ASD individuals had excellent health according to parent reports . Gastrointestinal disorders, sleep difficulties, and epilepsy occur at elevated rates in ASD . Enlarged head circumference was found in 16% of ASD individuals but 3% of comparison individuals, and enlarged total brain volume measured by structural MRI was found in 9% of ASD individuals in meta-analyses of relevant studies .

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Brain Cell Development Differs In Kids With Autism

HealthDay Reporter

FRIDAY, March 30, 2018 — Neurons in a brain area involved with social and emotional behavior normally increase as children become adults, but this does not occur in people with autism, new research contends.

Instead, children with autism spectrum disorder have too many neurons in this part of the brain — the amygdala — and lose neurons as they mature, according to researchers at the MIND Institute at the University of California, Davis.

“The amygdala is a unique brain structure in that it grows dramatically during adolescence, longer than other brain regions, as we become more socially and emotionally mature,” study senior author Cynthia Schumann said in a university news release.

“Any deviation from this normal path of development can profoundly influence human behavior,” she said. Schumann is an associate professor of psychiatry and behavioral sciences.

For the study, Schumann’s team examined the brains of 52 people who had died, including some with autism. They ranged in age from 2 to 48.

The researchers were surprised to find that the number of neurons in one part of the amygdala increased by more than 30 percent from childhood to adulthood in individuals who had developed normally.

In people with autism, however, the number of neurons was higher than normal in young children and declined with age.

“We don’t know if having too many amygdala neurons early in development in ASD is related to the apparent loss later on,” Schumann said.

Changes In Autism Severity Over Time

The white matter research builds on a previous MIND Institute study, which found that while many children experience fairly stable levels of autism symptoms throughout childhood, a significant portion can be expected to increase or decrease in their symptom severity over time.

This new analysis provides an important clue about the brain mechanism that may be involved in some of these changes, said Amaral.

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Researchers Find A Web Of Factors Behind Multiple Sclerosis

Researchers involved in the study came upon the myelination problem while looking for something else.

They were studying brain cells in mice with a gene mutation that causes Pitt-Hopkins syndrome, which can include features of autism spectrum disorder. “We saw a signature that suggested there might be something wrong with myelination,” Maher says. “So that was pretty surprising to us.”

More experiments confirmed that “there was a clear deficit,” in the cells that control myelination, which are called oligodendrocytes, he says. This was true not only in mice with the Pitt-Hopkins syndrome, but in other mouse models of autism, too.

Next, a biostatistics expert named Andrew Jaffe looked at a genetic analysis of brain tissue from people with autism who had died. And that experiment also found problems with the system that controls myelination.

To fully understand what’s going on though, the problem needs to be studied in developing brain tissue, Vaccarino says.

That should be possible, she says, using tiny clusters of human brain cells called brain organoids, which can be grown in a petri dish. Vaccarino’s lab has created brain organoids from the cells of people with autism spectrum disorder, which might reveal how the myelination problems begin, she says.

Brain myelination “really does not start in earnest until the first year or two of life,” Weinberger says. “And this is around the time that autism is first apparent.”

Additional Brain Regions Display Likely Secondary Structural And Functional Atypicalities In Asd

Parts of the Brain Affected by Autism

Additional brain regions display structural and functional abnormalities in ASD, predominantly visual cortical areas, inferior frontal gyrus and other regions of the PFC, caudate nucleus and putamen in the basal ganglia, hippocampus, sensorimotor cortex, cerebellum, and thalamus . It is suggested that some of these abnormalities are sequelae rather than etiological disruptions.

5.4.1. Visual cortex

See , Box 7.

Visual cortical areas processing motion and ventral temporal cortex subregions have been found by structural neuroimaging to be abnormal in ASD . In addition, functional neuroimaging meta-analyses have reported MTG and FG hypoactivity in social tasks in ASD versus TD controls .

At the neural level, as previously summarized, the amygdala relays strongly and reciprocally with the visual cortex, and these regions engage in recurrent processing . Conversely, amygdala dysfunction caused by surgical lesions in monkey or UrbachWiethe or other diseases in human induces hypoactivation of the visual cortex to emotional stimuli, as well as structural degeneration of it relative to healthy controls . At the behavioral level, social network size in monkeys and in humans has been found to be positively associated with VTC and STS volumes . Moreover, as the monkeys were independently allocated to different sized groups, variations in network size likely drove the variation in visual cortex volumes .

5.4.2. IFG

See , Box 8.

5.4.3. Caudate Nucleus

See , Box 9.

5.4.4. Hippocampus

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Major Symptoms And Features Of Asd

ASD comprises a multiplicity of abnormalities, commonly affecting sensory, motor, cognitive, emotional, repetitive behavior, activities of daily living, social, and language domains , and these are summarized in turn below. The essence of ASD symptomatology is summarized by Jolliffe et al. .

I feel it should have read, an inability to understand reality in the first place and that this itself leads to a person being withdrawn. This is where the problem in forming relationships and relating to other people comes in. The latter is difficult to do because you have never been able to make any sense of reality, and thus cannot understand why you should, and how you should, form a relationship, not that you have just withdrawn from reality. Reality to an autistic person is a confusing, interacting mass of events, people, places, sounds and sights. There seem to be no clear boundaries, order or meaning to anything. A large part of my life is spent just trying to work out the pattern behind everything. Set routines, times, particular routes and rituals all help to get order into an unbearably chaotic lifeIt is the confusion that results from not being able to understand the world around me which I think causes all the fear. This fear then brings a need to withdraw. .

Autism In The Brain Region By Region

27 February 2017

If the brain were a house with many rooms, you wouldnt find autism in just one of them. Autism has many causes and many forms. But no matter which form it takes, it seems to touch the entire brain. It permeates and perturbs the beams, foundation, wiring and piping of the house, rather than just, say, the kitchen.

Still, autism does have local effects: Different regions of the brain contribute uniquely to autisms impact on cognition, emotion and behavior.

In this special report, we detail the regional consequences of autism, one brain area at a time. Studies of the hippocampus, for example, may help explain the uneven effects of autism on memory. Investigations of the superior temporal sulcus may provide a window into the impact of autism on social perception.

The report is ongoing. Over time, our reporters will step into the various rooms of the brain to probe autisms effect on those regions.

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by Sarah DeWeerdt;/;20 August 2020

The brainstem controls such disparate functions as breathing, sensation and sleep all of which can be altered in autism.

by Sarah DeWeerdt;/;14 July 2020

The amygdala has long been a focus of autism research. But its exact role in the condition has been unclear.

by Sarah DeWeerdt;/;9 March 2020

Long known as the director of movement, the cerebellum may also coordinate social and cognitive abilities, including those central to autism.

by Angie Voyles Askham;/;15 October 2020

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Scientists Find Imperfections In ‘minibrains’ That Raise Questions For Research

That’s a problem because myelin provides the “insulation” for brain circuits, allowing them to quickly and reliably carry electrical signals from one area to another. And having either too little or too much of this myelin coating can result in a wide range of neurological problems.

For example, multiple sclerosis occurs when the myelin around nerve fibers is damaged. The results, which vary from person to person, can affect not only the signals that control muscles, but also the ones involved in learning and thinking.

The finding could help explain why autism spectrum disorders include such a wide range of social and behavioral features, says Brady Maher, a lead investigator at the Lieber Institute for Brain Development and an associate professor in the psychiatry department at Johns Hopkins School of Medicine.

“Myelination could be a problem that ties all of these autism spectrum disorders together,” Maher says. And if that’s true, he says, it might be possible to prevent or even reverse the symptoms using drugs that affect myelination.

“If we get to these kids really early, we might be able to change their developmental trajectory and improve their outcomes,” Maher says.

“It’s possible to make these cells healthier,” adds Dr. Daniel Weinberger, director of the Lieber Institute and a professor at Johns Hopkins. “And it’s never been a target of treatment in autism.”

The Effect Of High Functioning Autism On Gender Orientation

How Does Autism Affect the Brain? Part 2 of 2 | SCIENCE CAFE

The Autism Europe conference in Edinburgh had research presentations on the topic of gender dysphoria and its connection to high functioning ASD. Dr. Mark Stokes from;from La Trobe University in Melbourne Australia spoke about his recent study examining this topic.;The results from the international study found a higher percentage of those with ASD have gender distress, ambivalence and/or neutrality.

When compared to controls, individuals with ASD demonstrated significantly higher sexual diversity, reported gender-identities incongruent with their biological sex, and higher gender-dysphoric symptomatology.

The ASD group reported higher rates of asexuality; decreased heterosexual attraction and contact; increased homosexual attraction; ASD females reported higher homosexual contact; and were not concerned with the gender of their romantic partner. ASD individuals who were gender non-conforming reported better relationships with their opposite-sex peers during their schooling years than their gender-conforming peers did. The ASD group reported poorer mental health than controls and belonging to a sexual or gender-diverse group worsened this effect.

Increased non-heterosexuality in ASD may particularly fit predictions from the Extreme Male Brain theory of autism. An androgynous self-concept, gender ambivalence and dissatisfaction with culturally-dictated sex-roles emerged as major themes, which together may permit more fluid sexual-identities.

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Apparent Reversal Of Neurobiological Defects In The Adult

A remarkable finding in some recently studied animal models of autistic symptoms has been the surprising degree to which autistic symptoms have been apparently reversed or ameliorated by replacing or modulating gene function after birth or even in the adult. The first example of this came with a Drosophila model of Fragile × syndrome . Normally, the mutant flies have a defect in social/courtship learning and also have defects in the axons of neurons clustered in a brain region known as the mushroom body. The Fragile × disease pathway was modulated by administration of several drugs including metabotropic glutamate antagonists that can decrease the excessive protein translation caused by mutations in FMR or even using lithium carbonate, which modulates downstream signaling of the Fragile × pathway through the kinase GSK-3. Remarkably, in flies born with fixed defects in social behavior the phenotype could be rescued almost completely in adulthood by administration of metabotropic glutamate antagonists or even lithium .

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