Neural Circuit Taxonomy

Neural network circuits

Brain stuff -- interesting to find out what might go on in that grey matter.

"Precision psychiatry: a neural circuit taxonomy for depression and anxiety"

By Dr. Leanne M Williams, PhD

Summary

"Although there have been tremendous advances in the understanding of human dysfunctions in the brain circuitry for self-reflection, emotion, and cognitive control, a brain-based taxonomy for mental disease is still lacking. 

As a result, these advances have not been translated into actionable clinical tools, and the language of brain circuits has not been incorporated into training programs. 

To address this gap, I present this synthesis of published work, with a focus on functional imaging of circuit dysfunctions across the spectrum of mood and anxiety disorders. 

This synthesis provides the foundation for a taxonomy of putative types of dysfunction, which cuts across traditional diagnostic boundaries for depression and anxiety and includes instead distinct types of neural circuit dysfunction that together reflect the heterogeneity of depression and anxiety. 

This taxonomy is suited to specifying symptoms in terms of underlying neural dysfunction at the individual level and is intended as the foundation for building mechanistic research and ultimately guiding clinical practice."

And from Wikipedia:

"Dysfunction in the salience network have been observed in various psychiatric disorders, including anxiety disorders, post-traumatic stress disorder, schizophrenia, frontotemporal dementia, and Alzheimer's disease. 

The AI node of the salience network has been observed to be hyperactive in anxiety disorders, which is thought to reflect predictions of aversive bodily states leading to worrisome thoughts and anxious behaviors. 

In schizophrenia, both structural and functional abnormalities have been observed, thought to reflect excessive salience being ascribed to internally generated stimuli.

In individuals with autism, the relative salience of social stimuli, such as face, eyes, and gaze, may be diminished, leading to poor social skills."

On the Reading Table: NeuroTribes by Steve Silberman

Steve Silberman

NeuroTribes:

The Legacy of Autism and the Future of Neurodiversity

A groundbreaking book that upends conventional thinking about autism and suggests a broader model for acceptance, understanding, and full participation in society for people who think differently.

What is autism? A lifelong disability or a naturally occurring form of cognitive difference akin to certain forms of genius? In truth, it is all of these things and more -- and the future of our society depends on our understanding it. Wired reporter Steve Silberman unearths the secret history of autism, long suppressed by the same clinicians who became famous for discovering it, and finds surprising answers to the crucial question of why the number of diagnoses has soared in recent years.

Going back to the earliest days of autism research and chronicling the brave and lonely journey of autistic people and their families through the decades, Silberman provides long-sought solutions to the autism puzzle, while mapping out a path for our society toward a more humane world in which people with learning differences and those who love them have access to the resources they need to live happier, healthier, more secure, and more meaningful lives.

Along the way, he reveals the untold story of Hans Asperger, the father of Asperger’s syndrome, whose “little professors” were targeted by the darkest social-engineering experiment in human history; exposes the covert campaign by child psychiatrist Leo Kanner to suppress knowledge of the autism spectrum for fifty years; and casts light on the growing movement of “neurodiversity” activists seeking respect, support, technological innovation, accommodations in the workplace and in education, and the right to self-determination for those with cognitive differences.

NeuroTribes was the first science book to win the Samuel Johnson Prize. It has also won a California Book Award and a Books for a Better Life Award.

Mini Reviews

“Explores in fascinating, near-encyclopedic depth how autism has evolved… a gripping narrative written with journalistic verve.”
—The Guardian

“An essential resource. My own copy is already dog-eared.”
—Nature

“NeuroTribes is a sweeping and penetrating history, presented with a rare sympathy and sensitivity. It is fascinating reading; it will change how you think of autism, and it belongs, alongside the works of Temple Grandin and Clara Claiborne Park, on the bookshelf of anyone interested in autism and the workings of the human brain.”
— From the foreword by Oliver Sacks, author of An Anthropologist On Mars and Awakenings

“The monks who inscribed beautiful manuscripts during the Middle Ages, Cavendish an 18th century scientist who explained electricity, and many of the geeks in Silicon Valley are all on the autism spectrum. Silberman reviews the history of autism treatments from horrible blaming of parents to the modern positive neurodiversity movement. Essential reading for anyone interested in psychology.”
–Temple Grandin, author of Thinking in Pictures and The Autistic Brain

“NeuroTribes is remarkable. Silberman has done something unique: he’s taken the dense and detailed history of autism and turned the story into a genuine page-turner. The book is sure to stir considerable discussion.”
–John Elder Robison, Neurodiversity Scholar in Residence at The College of William & Mary and author of Look Me in the Eye

“Be prepared to overturn all prior knowledge you had about autism. With meticulous research, Steve Silberman has unearthed the surprising truths about the history of autism, uncovering the roots of the lie of the autism “epidemic.” Be prepared to share the deeply compassionate understanding that the author bestows on the many different individuals we now include in the autism spectrum. His empathy touches even the villains of the story, and this is both moving and apt when he advises us all to embrace diversity. This gripping and heroic tale is a brilliant addition to the history of autism.”
–Uta Frith, Emeritus Professor of Cognitive Development at University College London

“In this genuine page-turner, Steve Silberman reveals the untold history of autism: from persecution to parent-blaming, from Rain Man to vaccines, of doctors for whom professional ego trumped compassion, to forgotten heroes like Hans Asperger, unfairly tainted by Nazi links. It ends on an optimistic note, with ‘autistics’ reclaiming the narrative and defining autism in their terms — more difference than disability and an essential part of the human condition. Highly recommended for anyone with an interest in autism or Asperger’s, or simply a fascination with what makes us tick.”
–Benison O’Reilly, co-author of The Australian Autism Handbook

On the Reading Table: "Quiet" by Susan Cain

Susan Cain

This popular book got rather a lukewarm review from a New York Times books critic, but since I have a copy on hand, I'm reading it anyway.

Update: I finished reading it, and thought it rather good. Well worth reading for an introvert or those on the "autism spectrum."

Autism Linked With Too Many Brain Cells, Study Finds

 A model showing human brain-cell action is lighted by fiber optics; photo by John Schneeberger and Larry Kinney

         

by Amanda Chan  
USA Today, November 11, 2011

Autism is linked with having too many neurons in the part of the brain responsible for communication, cognitive development and social skills, according to a new study. Researchers said the finding suggests autism may begin when the baby is still in the womb.

Researchers from the Autism Center of Excellence at the University of California, San Diego found that boys with autism had 67 percent more neurons -- called cortical cells, which are made before a baby is born -- than boys without autism. Their work was published in the Journal of the American Medical Association.

"An excess of brain cells was found in each child with autism that we studied," study researcher Eric Courchesne, Ph.D. said in a statement. "While we think that ultimately not every child with an autism disorder will show this, our study does suggest that an abnormal excess of cells may be quite common among children with autism. This is an exciting finding because, if future research can pinpoint why an excessive number of brain cells are there in the first place, it will have a large impact on understanding autism, and perhaps developing new treatments."

Because these extra cells are only made before the child has been born, the findings suggest that something had to have happened prenatally.

Researchers examined the postmortem tissue of the prefrontal cortexes of 13 boys -- seven of them had autism, six did not. They found that the children with autism had more cortical cells in this brain region, and also had heavier brains than the children without autism.

Lizabeth Romanski, an associate professor of neurobiology and anatomy at the University of Rochester Medical Center who was not involved with the study, told USA Today that typically in the second trimester of pregnancy, a healthy baby's neurons are supposed to be "pruned" and die off in order for the brain to properly develop.

It needs to be determined if an autistic baby's brain isn't properly "pruning" these neurons, or, if the brain just develops too many of the neurons, Romanski told USA Today.

Previously in 2003, researchers from UCSD found that being born with a small head circumference, followed by a rapid increase in head circumference before age 1, is linked with autism. That research was also published in the Journal of the American Medical Association in 2003.

Signs of autism can occur early in life -- even in infancy -- for some children, while for others, it's something that occurs suddenly after the child has been developing without any problems for months or years, the Mayo Clinic reported.

And from the National Geographic website:

Being called a brainiac may be a compliment but when it comes to gray matter, a person can have too much of a good thing.  Scientists at University College London recently conducted a study that links high levels of distractibility with an increased volume of grey matter in the brain’s left superior parietal lobe.

The reasons for this are not yet fully understood, but it might have something to do with the way the brain pares away excess neurons as it matures in order to more effectively carry out certain tasks.  The brains of adults who suffer from attention deficit disorder may have failed to complete this process, and the connection may also help explain why children tend to be more easily distracted.

The results of the study appear in this week’s issue of The Journal of Neuroscience.