How to change your brain’s stress response

stressed brain crop

I’d like to tell you the story of an apprehensive pack of lab rodents that have been able to teach us something profound about stress. If you’ve seen my film The Connection you will have heard a little about these animals, which were studied by scientists at the National Centre for Biological Sciences.


In a series of studies, the Indian researchers took lab rats and restrained them for two hours a day, for ten days to stress them out. The scientists observed that the animals started acting anxiously even when they weren’t being constrained. When they were placed in a maze, they would prefer dark corners rather than getting out exploring bright open spaces.


Have a look at these videos, which were given to me by the researchers. The first video shows a normal rat, which hasn’t been stressed. When it hears a loud noise it continues it’s usual behavior sniffing around.



The second video shows a rat when has been put thought the stress protocol. When it hears the loud noise, the rat freezes in fear.



When the scientists looked at the brains of the anxious rats, the part of the brain responsible for the stress response called the amygdala, had gotten bigger. They continued stressing the animals out for two weeks and then stopped. What was interesting is that three weeks later they observed that the rats were still acting anxiously despite the fact they were no longer being put through the stress exercises. When the scientists measured their brains again, they saw that the rats’ amygdala were still enlarged.


The take home message for me here is that we may need to actually work with our brains in order to counteract any amygdala-enlarging experiences we have been exposed to.


The good news is that work being done in the lab of Dr. Sara Lazar from Harvard who is one of the experts I interviewed for The Connection, indicates there may be a simple, inexpensive, drug free way to shrink our amygdala.


Dr. Lazar put people who had never meditated through an eight-week meditation program and observed that the amygdala of her subjects actually got smaller. They also reported less stress and greater feelings of peace.


What’s interesting about Dr. Lazar’s study in comparison to the studies on the rats is that nothing in these people’s lives had changed other than their meditation practice. They still had their work stressors and usual complications of everyday living. The only thing that was different was their regular mediation practice and yet they were able to rewire their brain. The rats on the other hand showed signs of anxiety and enlarged stress centers; even after the fear inducing protocols had been stopped.


As Dr. Lazar explains in this video sliced from The Connection, what all this indicates is that meditation allows people to perceive their stressors differently and that in turn may allow the rewiring their brain. She concludes that all this isn’t so much about changing your life but rather, it’s about changing your relationship to your life.


The next logical step with this ground breaking research will of course be to teach rats to meditate, but in the meantime you might like to experiment with your own meditation practice and over time, observe yourself reacting differently in stressful situations.



  • Armando Ribeiro

    Impressive effect of chronic stress on animal behavior. In humans, the consequences can be even more serious, because besides the conditioning is possible that maladaptive cognitive responses are enabled, with losses to physical, emotional and mental health. Learning mindfulness will become increasingly necessary to meet the challenges of today's world. Congratulations on the "The Connection"!

  • Neri

    Also the freeze response is seen in children who are continually yelled at – they turn off and get more yelling as they are "ignoring" whatever is going on, rather than it seen as a protective response.
    Love getting your posts

  • Shannon

    Thanks Neri. I'll check out the research with children.

  • Shannon

    Thanks Armando. Couldn't agree more abut the importance of learning mindfulness. My 21 month old son is already starting to get the idea of taking deep breaths when he's upset. He's also working on his 'downward facing dog,' 'star pose' and 'mountain pose' to give him a foundation in understanding yoga. Hopefully he will have the tools from an early age to handle the ups and downs and pressures of this modern, hyper connected world. I have a feeling he's going to need them.

  • Gordo

    Great article. I have suffered from anxiety and stress throughout my life. It started in my childhood and as I have become older, I have noticed that it takes longer to recover. I could relate to the rat who was stressed when the noise occurred. If our brains are plastic then, like you suggest, we can reverse this intolerance level. Thanks. I shall have a go at some yoga poses.

  • Shannon

    Thanks Gordo.
    You might also be interested in this blog post about the two simple steps to counter stress.
    Wishing you well with those yoga poses. :-)

  • Alicia

    Hi Shannon,
    Congratulations on "The Connection"- it is such an amazing movie! I heard you on the "All in the Mind" podcast and subsequently dowloaded the movie and have watched it twice already. I am in the midst of having a chronic health issue diagnosed and have been motivated to meditate daily since watching your movie. Which my husband and mum (who has a chronic auto-immune disease) loved to! I wondered whether your recovery was linear, or you had setbacks/relapses along the way? I've been doing all the right things but have had an increase in my symptoms over the last week. Doubt can creep in and affect your "Faith" when this happens, but I guess you have to look LONG term right?!
    Also- I was curious as to what type of meditation you did? I know the type doesn't actually matter, but am just trying to find the best fit.
    Hats off to you again on a job well done!
    Alicia :)

  • Shannon Harvey

    Hi Alica,

    Thanks for watching the film and for letting me know about the impact that it made. You and other people like you are the reason I made it and it gives me, and the small team I work with, renewed energy to keep going when we hear your stories.

    I definitely had health set backs on my journey and expect that I still will. It's one of the reasons I'm careful to use the word recovery and not cure which is a term I've pinched from the OMS community. It's an ongoing journey and for me the ultimate goal is not about living longer, but rather about living better. I have a genetic make up that predisposes me to autoimmune dysfunction and I always will. No matter what I do I can't change my genes. But I can influence the way they are expressed.

    You've inspired me to write a post about how to handle set backs, which I'll do soon.

    The one thing I would say though is that set backs were a huge part of the process for me and provided me with an opportunity to consider what I was doing and how I was doing it. In a strange way they were the ultimate teacher. For example, I realized at one point in my journey that being on a highly restrictive diet was causing me some stress. I was dreading social occasions because I didn't want to be 'that difficult person' to have a meal with. So I did some mental re-framing around my approach to food and that helped moved things forward to a new stage.

    In terms of the meditation, I won't go into specific types or brands, because it's very different for different people, but I will say that many of the scientists seem to be focused on the 12 week MBSR course developed by Jon Kabat-Zinn who is one of the experts in the film.

    Wishing you all the best on your wellness journey,

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  • Jacqui Fisher

    Hey "Team Connection"! I just gave my stressed-out, 75 year old dad a copy of The Connection for fathers day… let's see what happens… hopefully he'll at least WATCH IT! I'm flat-out spreading the word! All the best, Jax

  • Yasmin Escobedo

    Thank you for an interesting post. I do have a small bone to pick: Why not post a link to the original article where this research was performed? Or mention the full name of the researchers that performed the study and a link to their lab and not just the institute they are based at? I realize that the vast majority of people don't have access to academic journals but most researchers are happy to send e-copies of their published manuscripts to all interested parties so you could facilitate that by adding more information about the authors.

  • Shannon

    Hi Yasmin,
    As a journalist who writes about the science showing the connection between our mind, body and health, it's quite hard to find the right level of information to provide to various people who are looking for different things. Some people only want to basic information and to know how it applies to their lives, and others want to delve into the details. I do normally directly link to the studies I refer to in my blogs, and have corrected this for this post. It seemed to have slipped through the cracks. The researchers were kind enough to provide me with the video to use for the blog, so I have been in touch with them.
    Here are some links that you might be interested in following up:

  • M Faulkner

    Yes let's ignore the obvious moral dilemma of intentionally tormenting living beings who possess the capacity for fear (just like humans! evidenced here!) to make our curious inquiry, bypassing any claim to humanity because, after all, they are just rats so who cares about the pain they feel? The important thing is learning new stuff in the name of science. Ignore the obvious and intentionally-inflicted distress on them because, well, progress! At its best!

About the author: Shannon Harvey

Shannon Harvey is a journalist and producer who was diagnosed with an autoimmune disease when she was 24 years old. Although doctors meant well, none could offer her a cause or a cure. Since then Shannon has been researching the latest scientific research linking her mind and body to health outcomes. Nearly 10 years have passed since her diagnosis and today Shannon is well and not taking medication. Shannon has worked as a television, radio and online journalist and producer and has a Master’s degree in Communications. She worked for the ABC and Fairfax before starting her own production company, Elemental Media. Shannon is the director of the feature film The Connection.



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The Connection is a feature documentary and blog about integrating the latest science in mind body medicine into our everyday lives.


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