Science’s last frontier

By Laura Eggerston

Fifty years ago, determining how the brain stores information and what underlies its ability to learn and remember would have topped brain researchers’ lists of unanswered questions.

However, neuroscience — the study of the brain — has made significant strides in understanding the plastic nature of the brain. We now know the brain can adapt and change throughout our lives, rewiring itself by weakening or strengthening the connections among nerve cells.

Nevertheless, says Jean-Claude Béïque, an associate professor at uOttawa’s Brain and Mind Research Institute, researchers don’t fully understand exactly how that process works.  

“Despite amazing progress, we are far from understanding how the brain learns. This is a fantastic mystery and is still amongst the most pressing unanswered questions in brain science,” says Béïque.

Béïque and other researchers are honing in on how to trigger the brain’s ability to adapt — known as neuroplasticity — in positive ways. Recovering from a stroke, overcoming learning disabilities, changing mood, even staving off the effects of Parkinson’s disease or Alzheimer’s are all potential changes to the brain researchers believe they can trigger if they discover how to stimulate the brain’s plasticity in the right ways. 

One breakthrough area of research Béïque highlights is what researchers know about the way synapses, or connections among nerves in the brain, change during memory formation. It’s a complex process, since one individual neuron can receive signals from up to 30,000 synapses (the connections among nerves).

Repetition strengthens synapses

When we use patterns of activity to activate those synapses, they become stronger. For example, repeating information such as phone numbers is one way of strengthening a particular network of synapses to help the brain remember that information. Repeating movements when playing a sport like tennis or ping-pong also strengthens and changes synapses in regions of the brain involved in motor control.

 “That is plasticity,” says Béïque. “That’s a form of learning … when you get better at ping-pong.”

The challenge for researchers is pinpointing sites in the brain that store different types of memories and to identify the networks of synapses specific to each type of memory that are activated in complex behaviours.

Networks regulate mood

Béïque is particularly interested by our response to adverse or traumatic events, and how it guides future behaviour. For example, every animal needs to assess whether or not a particular environment is safe, so the brain has many networks of synapses that assess and encode information. But if these networks become too strong — for example, due to enhanced, constant vigilance following an aversive event — they can contribute to anxiety or even post-traumatic stress disorder.

If researchers could determine what networks in the brain these experiences have strengthened too much, they might also be able to weaken the over-active networks, reducing anxiety or PTSD.  For instance, some researchers are experimenting with light, in the form of lasers, to trigger synapses in the brain to change their strength and regulate mood.

“We are getting better at studying these individual networks in isolation, the type of complex behaviours they underlie and how you can change their strength,” Béïque says. “What the understanding of plasticity offers us is if we can pinpoint different networks, then there are chances for us to manipulate their plasticity.”

Ultimately, identifying specific networks in the brain to weaken or strengthen to produce changes in mood or behaviour lead to new drugs that could stimulate the brain’s plasticity, promoting healing and improving lives.

On May 2, Béïque discussed research and discoveries in neuroplasticity during a “mini-medical school” lecture at Roger Guindon Hall, exploring the still-mysterious nature of the brain.