By better understanding how our brains work, can we change how we feel pain?

Professor Martyn Goulding is an internationally recognised and acclaimed molecular neuroscientist who leads the Molecular Neurobiology Laboratory at the Salk Institute - a San Diego-based research centre ranked in the top five in the world.

His unique approach to understanding how the brain works involves identifying specific attributes of spinal nerve cells, and may also be applied to other central nervous system neurons.

A Kiwi who graduated from the University of Auckland in the late 1980s, Goulding is working primarily in the field of spinal cord sensorimotor circuitry.

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Goulding has established an international reputation for his pioneering work on identifying and describing the function of spinal interneurons that generate and pattern rhythmic locomotor movements, and is also passionate about providing opportunities for the next generation of neuroscientists.

His visit home is hoped to help attract new talent to the Spinal Cord Injury Research Facility, developed by the university-based Centre for Brain Research.

Ahead of a free public lecture in Auckland on Wednesday evening, he spoke with science reporter Jamie Morton.

Back when you graduated university, how advanced was your field?

We had some understanding of how the spinal cord worked.

A lot of seminal work had actually been done during the 50s, 60s and 70s, using taps - and that work was really initiated by an Australian - Jack Eccles - who spent some time at the University of Otago.

He was really the first person to go and start to look at the spinal cord - and he was really interested in understanding how the brain worked.

But I should back up: when I left, I didn't head off to work on how the spinal cord functioned; I was really interested in how the foetus develops.

So I went off and worked in a lab in Germany, and essentially what we were doing was trying to figure out the genetic programmes that control the development of the foetus.

In doing that, I really started working on a number of genes that were expressed in the foetal nervous system and in particular, in the foetal spinal cord.

That provided us with a way to start to go in and look at the spinal cord circuitry and understand how it's put together and how it operates.

Today, there's still so much that scientists have to discover in this area. How exciting is the potential here?

It's immensely exciting.

It's a golden era for neuroscience.

For the past 40 years, we've been living in what I think has been a golden era for biology, but now is really the moment where we're able to start to understand how different parts of the brain work.

The real reason for that is we can now go in and manipulate individual components within the brain - those individual nerve cells - and we can kind of figure out what they do.

So there is a lot of things that have come together in the last 10 or so years, that have given us the ability to do things that we could have hardly dreamt of being able to do 15 or 20 years ago.

What would you ultimately hope to see achieved in this generation, or at least in the next?

There are two things that I'm really interested in.

As a scientist, you're just curious and you want to know how something works, maybe to a point where it's moderately simple.

So, if you think of the brain, what does it do?

The brain senses our surroundings, so it's kind of a perception-action machine, and it computes information that we need to move and make decisions and it takes that information and turns it into in an action or a behaviour.

What's really exciting is this idea that we can really understand how the brain, or some part of it, does that computation, as well as the flexibility that has been built into the system.

So, let's think of a simple reflex; the one most people would consider is touching something hot or a sharp object.

Why is it, that when you touch it, you always make that very same movement: you pull your hand away from it?

In this case, all of that operation is done within the spinal cord - but how is the spinal cord able to generate a response to that stimulus?

Or, let's say that you have an insect that bites you: how does the spinal cord know how to elicit that scratching behaviour we respond with?

So, that's looking at it on one level - and of course the second thing we are really interested in is being able to turn some of these discoveries into therapies or things that benefit our health and wellbeing.

Professor Martyn Goulding. Photo / Supplied
Professor Martyn Goulding. Photo / Supplied

If you look at patients who develop chronic pain, we know that certain forms of pain adapt, because there have been some changes within the internal workings of the spinal cord.

If we can understand how the spinal cord works and how those circuits are organised, maybe then, we could think about ways to go in and intervene.

I think this is really important because we are in the midst - or certainly this is the case in the US - of an opiate epidemic.

Part of the issue here is people often get hooked on these opiates because they are being used in association with some trauma or surgery to reduce the pain, but they also have these addictive qualities.

The other thing is you habituate over time to these opiates, to the point that you have to take larger and larger doses to get the same effect.

One of the things we might be able to do is come up with alternative strategies and therapies to modify these pain circuits.

Around two years ago, we made a fairly big discovery that came 50 years after a model for pain, called the Gate Control Theory, was proposed.

In a lot of patients, what happens is that normal touch modalities that we think would be pleasant - say, stroking of the skin eliciting a pleasant sensation - tends instead to elicit a much more painful sensation.

In our discovery, one of things we were able to do was identify specific types of neurons in the spinal cord that are important for making sure that painful stimuli are sensed as being painful, and that the pathways involved are separated from the pathways that are important for pleasant touch sensations.

So, you need to have a wall or a gate between the two - this is why it was called the Gate Control Theory - because, essentially what would happen is you would activate these neurons and they would shut the gate, so any pleasant touch sensations don't lead into the painful touch pathways.

Going forward, the hope is that these things will make a difference in terms of pain, how we treat spinal cord injuries, or neurodegenerative diseases that affect movement, or even better understanding the cellular basis for psychiatric disorders.

That said, is it still too hard to guess where we might be in 20 years?

Scientists are incredibly bad at making predictions - I think everyone is.

I've talked with people, you know, Nobel laureates, and there will often be times where we'll make predictions that might be somewhat fanciful but find that they come through, and other times where we suspect we may be able to do something, but we fall short.

But I do really think we are beginning to understand a lot more about how our bodies work and that's going to teach us a number of things about how to maintain healthier lifestyles.

It's also going to allow us to develop clever strategies to deal with diseases.

At the moment, maybe the best examples are some of the new cancer treatments that are emerging.

Here, people are understanding the fundamentals of what's going on in cancer cells, and the way these cells interact with the body, and we are coming up with clever strategies to interfere with those processes.

I think the same thing is going to happen with better understanding how the brain works - and how we are going to be able to intervene with greater precision.

Goulding's lecture, titled Understanding how the brain works: the real challenge, will be held at 6pm on Wednesday, March 15, at the Auckland Medical Research Foundation lecture theatre, at the University of Auckland's Faculty of Medical and Health Sciences, 85 Park Road, Grafton.