How Are Purkinje Cells in the Cerebellum Linked to Autism?

Scientists at the annual 2014 Society for Neuroscience meeting (November 14-19) in Washington D.C. presented unpublished research that links the Purkinje cells of the cerebellum with autism spectrum disorders (ASD).

In the 19th century, Santiago Ramón y Cajal made detailed sketches of Purkinje cells. Ramón y Cajal also provided detailed written descriptions of how these cell types were associated with neural structures. He was brilliant at producing detailed renderings of cellular structures and their connectivity.

Over a century later, neuroscientists are using the latest brain imaging techniques to grasp how Purkinje cells are connected within the cerebellum and how they communicate with other brain regions.

In November 2014, unpublished research was presented at the Society of Neuroscience conference that opens up fascinating possibilities of better understanding how Purkinje cells are involved in emotional and cognitive processes. In particular, there is growing evidence that Purkinje cells and specific brain regions within each cerebellar hemisphere may be directly linked to autism.

My father, Richard Bergland, was a neuroscientist, neurosurgeon, and author of The Fabric of Mind (VIking). My father was obsessed with Purkinje cells and the cerebellum. He passed this obsession on to me.

My dad always said, “Whatever the cerebellum is doing, it’s doing a lot of it.” Because of my father’s insights, I made Purkinje cells and the cerebellum the prime driving force of The Athlete’s Way (St. Martin’s Press).

Over the past decade I have had my antennae up for any new research about Purkinje cells and the cerebellum. I was thrilled to see Purkinje cells and the cerebellum take center stage at the annual Society of Neuroscience meeting this week and am excited to share these findings with my Psychology Today readers.

Background of Purkinje Cells and the Cerebellum

In 1504, Leonardo da Vinci made wax castings of the brain and coined the term “cerebellum” which is Latin for “little brain.” The cerebellum is only 10% of brain volume but holds over 50% of your brain’s total neurons.

Purkinje cells are named after Johannes Purkinje, who first identified these neurons in 1837. Dr. Purkinje was also the first person to identify the individuality of the human fingerprint. Purkinje cells held in the cerebellum are responsible for communicating information from the cerebellum to the cerebral cortex.

The traditional view on the role of the cerebellum was that it was primarily responsible for balance and motor control but that the control of our cognitive functions including social intelligence and linguistics were seated in the cerebral cortex. This view is radically changing.

The cerebellum is now believed to play a central role in regulating our emotional, psychological, and sensory interactions with the world around us and ourselves.

Cerebellar (of or pertaining to the cerebellum) dysfunction can impede both motor skills, as well as, executive and cognition function. The cerebellum and cerebrum work in concert to streamline implicit and explicit (declarative) learning and memory. The cerebellum is also important for communicating language and our intuitive understanding of emotions.

The cerebellum allows you to lock onto a target while you/re moving the head (VOR) or to shift your eyes when you decide to make eye contact or divert your gaze.

The cerebellum allows you to lock onto a target while you/re moving the head (VOR) or to shift your eyes when you decide to make eye contact or divert your gaze.

In autism spectrum disorders, the brain consistently shows defects in Purkinje cells, which have a single axon that projects from the cerebellum and creates connectivity from the cerebellum to most other brain regions.

Previous research has found cerebellar dysfunction in people with ASD through postmortem studies of brain samples that showed loss of Purkinje cell volume. Over the past few years, a variety of studies have confirmed this phenomenon in the majority of autistic brains.

Autism Researchers Are Putting the Cerebellum in the Spotlight

In a lecture at the 2014 Society of Neuroscience conference, Matt Mosconi, assistant professor of psychiatry at the University of Texas Southwestern in Dallas, presented unpublished research that shows how people with autism become overwhelmed when translating visual information into delicate or nuanced muscular responses.

In a video game that required holding a bar still using varying degrees of pressure from the fingertips, people with autism struggle to hold the mobile bar still, perhaps overcompensating when making adjustments in response to movement. Mosconi and his colleagues scanned the brains of participants with autism and 23 controls as they performed this task in a scanner.

The team found that with low sensitivity, people with autism showed weak responses in neural circuitry in a feedback loop going into and out of the cerebellum. In high sensitivity levels of the game, people with autism displayed hyperexcitability in sensory brain regions outside the cerebellum which appeared to be overcompensating for cerebellar deficiencies.

Developing an App for Children With Autism

Another exciting new and unpublished finding presented at the 2014 Society for Neuroscience meeting was a touch-screen game based on popular cartoon character that can improve cerebellar implicit learning in children with autism. Researchers hope that in the future applications like this could allow scientists to tailor treatments for children with autism.

The game is designed to evaluate implicit learning, which occurs without the learner being consciously aware of what he or she is being taught explicitly or held in declarative memory. Autism researchers are becoming more and more interested in the mechanisms of implicit learning because these automatic skills are involved in language and the unspoken rules of social engagement which become intuitive through implicit learning. .

Rebecca Jones, a postdoctoral researcher who works with Catherine Lord at Weill Cornell Medical College in New York, presented the findings. The researchers are introducing their game to young children with autism or intellectual disability in an attempt to find out whether there are explicit learning deficits specific to autism.

These interventions aim to teach children how to have an implicit more intuitive response to social cues instead of relying on the explicit memory of the cerebral cortex.

Right Brain and Left Brain Functions Differ in People With Autism

Most people with autism have been found to process language on the right hemisphere of their cerebral cortex, which is strongly linked to the left hemisphere of the cerebellum. This shift in language processing to the right side in the cerebrum and the left side in the cerebellum might be a way of compensating for some other deficits of structure or connectivity.

A fascinating study from 2007 found that healthy children tend to show activity in the superior temporal gyrus on both sides of the brain at very young ages, and then develop more left-hemisphere activity over time. In contrast, children with autism don't show left-hemisphere dominance in this age range.

Brain imaging shows distinct signatures in the language circuits of young toddlers with autism when they sleep. Neuroscientists have found that when children with autism hear a bedtime story, they show more activity on the right side of the cerebrum, rather than the left side.

When toddlers with autism are sleeping and hear language, they show more activity in the right cerebral cortex. This is surprisingly different from children without autism who are believed to process grammar and vocabulary in the left side of the brain.

Interestingly, when children without autism hear an intelligible version of a bedtime story played backwards they show greater activity on the left side of the brain, whereas children with autism have more activity in the right hemisphere.

Understanding Subregions of the Cerebellum Is the Next Frontier

Sam Wang, Associate Professor of Molecular Biology at Princeton University, points out that many studies are trying to pin down subregions and “microzones’ within the cerebellum as neuroscientists strive to better understand overall cerebellar function.

In a press release Wang said, "One should not think of the cerebellum as a single monolithic object. I think that sharpening one's understanding of which part of the cerebellum might contribute to loss of function would be pretty interesting."

In his review of the highlights of the 2014 Society of Neuroscience conference Sam Wang said:

“An interesting presentation by Peter Tsai and Mustafa Sahin addressed the question of whether early-life contributions by cerebellar Purkinje cell function can affect later behavioral function. I like the way they are examining whether rescue at different points in life can affect later behavioral outcomes. Their work points toward the possibility outlined in my recent review, that brain regions can have effects that reach far beyond what they themselves are thought to do in the adult animal.”

Wang also concluded, “Work presented by Amaicha Mara Depino uses a totally different method, that of neuroinflammatory insult. In their case, they explored anatomical specificity: They found that certain lobules of the cerebellum (specifically, VI and VII, near the midline) had effects on social interaction, but other lobules (IV and V) did not. This suggests that different parts of the cerebellum have different roles, just as different layers of the neocortex have different functions.”

Conclusion: How Can You Optimize Your Cerebellar and Cerebral Function and Connectivity?

I have a hunch that in the 21st century neuroscientists will begin to focus more on understanding how specific regions of the cerebellum are related to neurological disorders.

As with any brain function, oftentimes neuroscientists learn and identify how various brain regions function optimally by first identifying dysfunctions in maladies like autism spectrum disorder.

These new findings on the role of Purkinje cells and ASD are promising because they offer clues for developing pharmacological and tailored behavioral treatments for people with autism spectrum disorders. These findings also offer valuable clues for the neuroscience of optimizing brain function so that people from all walks of life can fulfill their individual human potential.

In the late 20th century, the focus of many was on left brain-right brain and various regions of the cerebrum. I believe that in years to come that the focus will be on specific regions in both hemispheres of the cerebellum and cerebrum and the role they play in how humans interact with one another, ourselves, and the world around us.

Your cerebellum is an underestimated powerhouse that has been in the shadows for too long. It’s exciting to see neuroscientists finally putting the cerebellum in the spotlight.

If you'd like to read more about Purkinje cells, the cerebellum, and implicit learning check out my Psychology Today blog posts:

• "Research Links Autism Severity With Motor Skill Deficiencies"
• "How Is the Cerebellum Linked to Autism Spectrum Disorders?"
• "The Neuroscience of Knowing Without Knowing"
• "Is Cerebellum Size Linked to Human Intelligence?"
• "Primitive Brain Area Linked to Human Intelligence"
• "The Mysterious Neuroscience of Learning Automatic Skills"
• "Too Much Chrystalized Thinking Lowers Fluid Intelligence"
• "Why Does Overthinking Cause Athletes to Choke?"
• "Toward a New Split-Brain Model: Up Brain-Down Brain"
• "Neuroscientists Discover How Practice Makes Perfect"
• “Childhood Family Problems Can Stunt Brain Development”
• "The Neuroscience of Calming a Baby"
• “Why Is Dancing So Good For Your Brain?”
• “The Neuroscience of Madonna’s Enduring Success”
• "Gesturing Engages All Four Brain Hemispheres"
• "The Neuroscience of Superfluidity"
• "One More Reason to Unplug Your Television"
• "Better Motor Skills Linked to Higher Academic Scores"
• "Hand-Eye Coordination Improves Cognitive and Social Skills"
• "The Neuroscience of Imagination"
• "Can Practice Alone Create Mastery?"
• "No. 1 Reason Practice Makes Perfect"

Follow me on Twitter @ckbergland for updates on The Athlete’s Way blog posts.

Photo Credits:

• Wikimedia Commons
• Christopher Bergland hand sketched diagram and home photo.