What Makes People Social? The Answer May Be Found in Petri Dish Brains Made from Teeth.

Research being done with brain organoids ("mini brains" deriving from cells, such as teeth) from those with autism and Williams syndrome is providing insight into what makes humans social. 

Sometimes the Tooth Fairy gives more than a dollar underneath your pillow.

In the case of Dr. Alysson Muotri, associate professor of pediatrics and cellular and molecular medicine at UC San Diego School of Medicine and a noted expert on autism, the Tooth Fairy gave new insight into what may make humans social. Through Dr. Muotri's Fairy Tooth Kit Collection campaign, donated baby teeth from both those with autism and those unaffected were collected for research. 

A tiny brain was then created in a petri dish from the teeth.

These miniature brains may provide a window into the human spectrum of sociability, helping us better understand why certain individuals like those with autism have diminished social skills. It may also help us understand how humans evolved to be as social as we generally are.

Called Brain or Cerebral Organoids, Dr. Muotri and his team were able to create these so-called mini-brains by extracting the pulp cells in the teeth and converting them into brain cells. This is done through the induced pluripotent stem cell (iPS) technique, a reprogramming of cells to be in a stem cell-like state. These neural progenitor cells are able to create networks similar to the developing cortex of a human brain. 

Dr. Muotri's research showed that the organoids using cells from those with autism had fewer neural connections than those unaffected. 

While autism is generally associated with low degrees of sociability, Williams syndrome is a rare genetic disorder where those affected have an extremely high level of sociability to the point of talking with strangers. It is often referred to as the "opposite of autism."

Dr. Muotri and his team of researchers at the University of California San Diego, along with researchers at the Salk Institute of Biological Studies, examined organoids grown from those affected by Williams syndrome. The team noticed that instead of former fewer neural connections like the autism organoids, the organoids contained an abnormally high level of neural connections.

Organoids derived from cells unaffected by a neurobiological disorder were right in the middle. In other words, the level of neural connections in the mini-brains correlated with the sociability of person. The higher the sociability (from autism to unaffected to Williams Syndrome), the greater the neural connections in the cerebral organoid.  

Speaking to New Scientist, Dr. Muotri said:

“The differences are striking, and go in opposite directions. In Williams syndrome, one of the cortical layers makes large projections linking into many other layers, and these are important for sociality. By comparison, autism-linked brains are more immature, with fewer synapses."

The connection between synapses and sociality was also found by the research team when examining donated brains from those who had autism or Williams syndrome. In addition, another research team working with brain organoids recently found that patients with idiopathic autism overproduced inhibitory neurons.

In the December 2015 issue of the journal Developmental Biology, researchers Madeline Lancaster and Iva Kelava explored both the promise and challenges of cerebral organoids. In the article, Dishing out mini-brains: Current progress and future prospects in brain organoid research, they argue that brain organoids can successfully model neurodevelopmental conditions such as idiopathic autism and the brain organoids "model early human embryonic and fetal brain development to a remarkably high degree."

While the work on brain organoids is quite new, there appears to be a great deal of promise in the research with unlocking some of the secrets of the brain.

"Brain organoids (and organoid systems in general), which adequately model tissue development and physiology, are a relatively new development, and the field has exploded in the last several years. Thus, it is easy to envisage that in 10–20 years from now (or even less) we will be able to almost fully mimic development of certain tissues in vitro. In addition, further improvements in the technique might allow us to model adult brain physiology and disorders of the adult and ageing brain."

Madeline Lancaster is a leading researcher in working with brain organoids and is credited with discovering the method of growing neurons in a petri dish long enough to develop characters is the human brain. 

"I'm mainly interested," she told MIT Technology Review, "in figuring out what it is that makes us human.”

LinkedIn meets Tinder in this mindful networking app

Swipe right to make the connections that could change your career.

Getty Images
Swipe right. Match. Meet over coffee or set up a call.

No, we aren't talking about Tinder. Introducing Shapr, a free app that helps people with synergistic professional goals and skill sets easily meet and collaborate.

Keep reading Show less

4 reasons Martin Luther King, Jr. fought for universal basic income

In his final years, Martin Luther King, Jr. become increasingly focused on the problem of poverty in America.

(Photo by J. Wilds/Keystone/Getty Images)
Politics & Current Affairs
  • Despite being widely known for his leadership role in the American civil rights movement, Martin Luther King, Jr. also played a central role in organizing the Poor People's Campaign of 1968.
  • The campaign was one of the first to demand a guaranteed income for all poor families in America.
  • Today, the idea of a universal basic income is increasingly popular, and King's arguments in support of the policy still make a good case some 50 years later.
Keep reading Show less

Dead – yes, dead – tardigrade found beneath Antarctica

A completely unexpected discovery beneath the ice.

(Goldstein Lab/Wkikpedia/Tigerspaws/Big Think)
Surprising Science
  • Scientists find remains of a tardigrade and crustaceans in a deep, frozen Antarctic lake.
  • The creatures' origin is unknown, and further study is ongoing.
  • Biology speaks up about Antarctica's history.
Keep reading Show less

Why I wear my life on my skin

For Damien Echols, tattoos are part of his existential armor.

  • In prison Damien Echols was known by his number SK931, not his name, and had his hair sheared off. Stripped of his identity, the only thing he had left was his skin.
  • This is why he began tattooing things that are meaningful to him — to carry a "suit of armor" made up the images of the people and objects that have significance to him, from his friends to talismans.
  • Echols believes that all places are imbued with divinity: "If you interact with New York City as if there's an intelligence behind... then it will behave towards you the same way."
Keep reading Show less