Research Links Autism to Brain Structure
Cells in Amygdala Implicated, According to Autism Speaks-funded Research
For years, researchers have been examining the relationship between the size of the brain structure known as the amygdala and autism-specific behaviors, and have also been working to understand how it this brain structure is activated under different social situations. However, the neurobiological cause of the difference in size and responsiveness of this brain structure is largely unknown.
A new study published by Autism Speaks-funded researcher David Amaral in the July 19, 2006 issue of the Journal of Neuroscienceaddressed this challenge by studying post-mortem tissue provided by the Autism Tissue Program, an Autism Speaks-supported program. He and his colleague, Dr. Cynthia Schumann at the MIND Institute at UC Davis, reported a change in the number of neurons in the lateral nucleus of the amygdala of men diagnosed with autism. This suggests that a change in cell number in this region may contribute to deficits in behaviors regulated by the amygdala, including processing of emotions and fear.
To read more about this study, look below.
UC Davis M.I.N.D. Institute
UC DAVIS M.I.N.D. INSTITUTE RESEARCHERS FIND FEWER NEURONS IN THE AMYGDALA OF MALES WITH AUTISM
Study quantifies a neuroanatomical distinction of the autistic brain
July 18, 2006
(SACRAMENTO, Calif.) — Researchers at the University of California, Davis, M.I.N.D. Institute have discovered that the brains of males with autism have fewer neurons in the amygdala, a part of the brain involved in emotion and memory.
The study, published in the July 19 issue of the Journal of Neuroscience, is the first neuroanatomical study to quantify a key difference in the autistic amygdala.David Amaral, research director of the UC Davis M.I.N.D. Institute, and former graduate student Cynthia Mills Schumann counted and measured representative samples of neurons in the amygdala of nine postmortem brains of males who had autism and 10 postmortem brains of males who did not have autism.
Both subject groups ranged in age from 10-to-44 years at the time of death. Using a technique known as “unbiased stereological analysis,” Schumann and Amaral counted neurons using a computer-aided microscope system.
They found significantly fewer neurons — cells responsible for creating and transmitting electrical impulses — in the whole amygdala and its lateral nucleus in the brains of people with autism.
“This is the first quantitative evidence of an abnormal number of neurons in the autistic amygdala and the first study to use modern unbiased sampling techniques for autism research,” Amaral said.“While we have known that autism is a developmental brain disorder, where, how and when the autistic brain develops abnormally has been a mystery,” said Thomas R. Insel, a physician and director of the National Institute of Mental Health . “This new finding is important because it demonstrates that the structure of the amygdala is abnormal in autism.
Along with other findings on the abnormal function of the amygdala, research is beginning to narrow the search for the brain basis of autism.”
Now affecting 1 in every 166 children and primarily affecting males, autism is a lifelong neurodevelopmental disorder characterized by social and communication deficits.
While autism has clear behavioral indicators, the neural alterations leading to the deficits have been difficult to pinpoint. In studies dating back to the mid-1980s, researchers began focusing on the amygdala because of its importance in generating appropriate emotional responses and assimilating memories that are key to social learning — functions that are impaired by autism.
“Previous magnetic resonance imaging studies from several laboratories, including the M.I.N.D. Institute, have indicated precocious enlargement of the amygdala in young children with autism,” said Schumann, who is now a postdoctoral researcher at the UC San Diego School of Medicine.
“But these studies were not able to determine whether the number of neurons were different in the autistic amygdala.”
Interpreting these earlier qualitative studies was hampered because many postmortem brains available for research were from individuals who had autism as well as epilepsy, a condition known to cause pathology of the amygdala.
“Back when these studies were conducted, it wasn’t easy to acquire the brain of a deceased person who just had autism,” Amaral explained. “We are fortunate now to have the Autism Tissue Program, funded by the National Alliance for Autism Research and the National Institutes of Health. With their help, we were able to analyze more than double the number of previously examined postmortem brains, none of which had seizure disorders or any major neurological disorder other than autism.”
“A better understanding of the neurobiology of the amygdala is crucial to advance autism research, and this study helps answer many important questions about the fundamental basis of autism,” said Andy Shih, chief science officer for the National Alliance for Autism Research, which is now merged with Autism Speaks. “Autism Speaks and the Autism Tissue Program were proud to support this project so that these important discoveries could be made.”
By counting the actual number of neurons in tissue samples, the researchers also overcame a methodological concern raised by studies that described changes in neuronal density, or neurons per unit volume, in portions of the amygdala.
“Differences in neuron density could just indicate changes in tissue volume rather than changes in total cell number. The only way to determine the actual difference is to systematically count samples of neurons in a defined volume,” Amaral said.
With this latest confirmation that the amygdala is pathological in autism, Amaral and colleagues will now determine why there are fewer neurons in the amygdala and if other parts of the brain are similarly affected.
“We need to look at other brain regions to find out if the cell loss is idiosyncratic to the amygdala or a more general phenomenon,” he said. “We’re in the very early stages of understanding autism and its neurological pathologies. It’s clearly a process with many steps, and at least we are now one step further.”
Additional research will also help identify the developmental point in time at which the neuron reduction actually occurs, which the current study does not address.“
One possibility is that there are always fewer neurons in the amygdala of people with autism. Another possibility is that a degenerative process occurs later in life and leads to neuron loss. More studies are needed to refine our findings,” said Schumann.
Schumann and Amaral’s research was funded by the National Alliance for Autism Research and the National Institutes of Health.
A copy of the article, “Stereological Analysis of Amygdala Neuron Number in Autism,” is available from Caitlin Quigley in the Society for Neuroscience
Public Information Department.
She can be reached at (202) 962-4000 or firstname.lastname@example.org.
The UC Davis M.I.N.D. (Medical Investigation of Neurodevelopmental Disorders) is a unique, collaborative center bringing together parents, scientists, clinicians and educators for research on autism, fragile X syndrome, learning disabilities and other neurodevelopmental disorders. For more information, visit www.mindinstitute.org.
Autistic people have fought the inclusion of ABA in therapy for us since before Autism Speaks, and other non-Autistic-led autism organizations, started lobbying legislation to get it covered by insurances and Medicaid.
ABA is a myth originally sold to parents that it would keep their Autistic child out of an institution. Today, parents are told that with early intervention therapy their child will either be less Autistic or no longer Autistic by elementary school, and can be mainstreamed in typical education classes. ABA is very expensive to pay out of pocket. Essentially, Autism Speaks has justified the big price tag up front will offset the overall burden on resources for an Autistic’s lifetime. The recommendation for this therapy is 40 hours a week for children and toddlers.
The original study that showed the success rate of ABA to be at 50% has never been replicated. In fact, the study of ABA by United States Department of Defense was denounced as a failure. Not just once, but multiple times. Simply stated: ABA doesn’t work. In study after repeated study: ABA (conversion therapy) doesn’t work.
What more recent studies do show: Autistics who experienced ABA therapy are at high risk to develop PTSD and other lifelong trauma-related conditions. Historically, the autism organizations promoting ABA as a cure or solution have silenced Autistic advocates’ opposition. ABA is also known as gay conversion therapy.
The ‘cure’ for Autistics not born yet is the prevention of birth.
The ‘cure’ is a choice to terminate a pregnancy based on ‘autism risk.’ The cure is abortion. This is the same ‘cure’ society has for Down Syndrome.
This is eugenics 2021. Instead of killing Autistics and disabled children in gas chambers or ‘mercy killings’ like in Aktion T4, it’ll happen at the doctor’s office, quietly, one Autistic baby at a time. Different approaches yes, but still eugenics and the extinction of an entire minority group of people.
Fact: You can’t cure Autistics from being Autistic.
Fact: You can’t recover an Autistic from being Autistic.
Fact: You can groom an Autistic to mask and hide their traits. Somewhat. … however, this comes at the expense of the Autistic child, promotes Autistic Burnout (this should not be confused with typical burnout, Autistic Burnout can kill Autistics), and places the Autistic child at high risk for PTSD and other lifelong trauma-related conditions.
[Note: Autism is NOT a disease, but a neurodevelopmental difference and disability.]
Fact: Vaccines Do Not Cause Autism.