In “The Tale of Johnny Town mouse” by Beatrix Potter, the story tells of the different experiences of “Johnny, who was born in a cupboard” and “Timmie-Willie, who was born in a garden” when they visit each other’s environment.

If you ask someone who lives in a big city, how they would like to spend their down time or where they plan to retire to, how many times have you heard the wish expressed for a simpler and quieter life in the country?

When my father retired from his busy veterinary practice, my parents moved to live on a farm in a remote beauty spot.

The question then often asked is, if we have spent all our lives living in cities with their hustle and bustle, would we then we would miss all that busyness, the people and all the social activities that city life can bring? Would we have become so habituated to all the noise, the traffic, the urgency of everything we do, that our brains don’t notice it anymore?

Perhaps not.

The results of an international study recently published in Nature showed that where we spend the first 15 years of our life makes a big difference to how “wired” we are for potential stress for the rest of our lives.

Being born and brought up living in a city, is likely to put you at a greater lifetime risk of mood disorders anxiety and schizophrenia.

Why is that?

We have specialised brain regions that deal with our emotions such as fear and anxiety and stress control.
One area is called the amygdala. This structure is associated with recognising threat or danger to us and instigates an emotional response to it. These threats come partly in the form of exposure to noise and pollution. Other threats include time pressure and being around lots of people.

The other brain area now identified as being relevant here, is called the anterior cingulate or ACC. The ACC acts as more of a global regulator of stress and was shown in the study to be more highly activated and to remain so, if you are born and brought up in a city environment.

In other words our brain then becomes attuned to a higher level of vigilance. It remains on high alert and is more easily triggered by stresses. Over time this can them manifest itself in the form of anxiety and other mental health disorders.

What are the implications of this?

Well the suggestion here, is that while we remain living in a noisy city environments, whether by choice or necessity, it is really important to schedule in some breaks to “get away” to somewhere with more peace and quiet. Your brain needs that time out to quieten down the emotional load. It’s all about balance.

Half of the world’s population now lives in cities. So developing and maintaining healthy urban environments is crucial for our mental health and well-being.

Have you scheduled in your next break yet?

Ref:
Florian Lederbogen, Peter Kirsch, Leila Haddad, Fabian Streit, Heike Tost, Philipp Schuch, Stefan Wüst, Jens C. Pruessner, Marcella Rietschel, Michael Deuschle, Andreas Meyer-Lindenberg. City living and urban upbringing affect neural social stress processing in humans. Nature, 2011; 474 (7352): 498 DOI: 10.1038/nature10190

What is stress?

It has been defined in a number of different ways but for the purpose of this article, is taken to be: a sense of irritation, tension, nervousness, anxiety, fear or difficulty sleeping, lasting over a month as a result of problems at home, at work or health worries.

Stress is a term often used in society, but do we really understand what stress actually is and why it matters to brain health?

Should we worry about stress as a risk factor for dementia and Alzheimer’s?

Severe chronic stress is bad for our health. This is the sort of stress that keeps you awake at night with worry. This is the sort of stress that is associated with excessive release of catecholamines, the substances associated with the “flight or fight” syndrome. Here cortisol, which in normal amounts causes no problem, exerts a toxic effect on our neurons.

Studies looking at dementia risk and stress.

A high level of cortisol in the brain, by accelerating the process of biochemical and behavioural pathology, has been linked to an increased risk of dementia.

The results of a population study on a group of 1400+ women in Sweden followed for over 35 years from 1968 was published in 2010. They were aged between 38 and 60 when first recruited to the study and answered questions including one asking about psychological stress in 1968, 1974, and 1980.

Of the group, 161 women developed dementia (mostly in the form of Alzheimer’s disease). Those who had reported having repeated periods of stress in middle age were shown to have a 65% increase in their risk of dementia. In those who reported stress in all three surveys had double the risk. In this study, the timing of the stress was relevant. In other words, exposure to repeated stress in middle age appears to elevate the risk

Should this be a surprise? Maybe not. It is already known that stress has a negative impact on our health, increasing our susceptibility to an impaired immune response and an increased risk of cardiovascular disease in the form of stroke, high blood pressure and heart attack.

Previous animal studies had also previously shown an association of stress and dementia risk.

But it also needs to be put into perspective. The vast majority of women participating in the study did not develop dementia. So while stress is significant and needs to be dealt with appropriately, it is important not to stress, that being stressed will lead you to developing dementia!

In another study, the physiological changes in neurons susceptible to the effect of stress were examined were examined.
Here, researchers using rats, showed how stress led to an increase in the formation of abnormal clumps of tau protein in neurons. This led to increased cell death, particularly in the area of the brain associated with learning and memory i.e. the hippocampus and prefrontal cortex.

This builds on previous findings that stress is associated with the build up of beta amyloid, another protein associated with the pathology of Alzheimer’s disease.

The next step will now be to examine to see whether these results implicating stress as a possible trigger of neurodegenerative disease can be replicated in humans. One of the researchers Osborne Almeida, has also questioned the relationship between stress and depression. Stress has been recognised as a major risk to a person’s propensity to develop major depression. Could beta amyloid and tau proteins, by being accelerated to form under the influence of stress, be implicated in the development of this disease as well?

Stress Management: The need to manage stress levels.

The bottom line is that the effect of stress on our health and well-being should not be underestimated.

• Be aware that stress is potentially harmful to your health.
• Make sure you know what you can do and how you can mitigate the effects of stress.

This could be in the form of physical exercise, talking to a trusted friend or family member, seeking medical advice, learning meditation, practicing yoga or tai chi, deep breathing or mindfulness training.

So don’t ignore symptoms of stress either personally or in someone else. Take the necessary steps to bring your stress under control and minimise any potential risk to the health of your body and brain.

Refs:

L. Johansson, X. Guo, M. Waern, S. Ostling, D. Gustafson, C. Bengtsson, I. Skoog. Midlife psychological stress and risk of dementia: a 35-year longitudinal population study. Brain, 2010; DOI: 10.1093/brain/awq116

Ioannis Sotiropoulos, Caterina Catania, Lucilia G. Pinto, Rui Silva, G. Elizabeth Pollerberg, Akihiko Takashima, Nuno Sousa, and Osborne F. X. Almeida. Stress Acts Cumulatively to Precipitate Alzheimer’s Disease-Like Tau Pathology and Cognitive Deficits. Journal of Neuroscience, May 25, 2011; 31(21):7840-7847 DOI: 10.1523/JNEUROSCI.0730-11.2011

Have you noticed how with age and UV exposure some plastics change, becoming more brittle? Well, it seems that as we get older, our plastic brain loses some of its plasticity too.

Our middle aged brains start to notice that it gets harder to learn stuff and keep it in our heads. It takes more effort to pay attention to what we are doing and more practice to embed new memories. We’ve found out that part of this is due to a slowing down of the brains’ processing speed and our increasing levels of distractibility. But new research now indicates that there is another reason for this; our lovely plastic brain becomes less plastic.

What does this mean?

When we talk about our brain being plastic, we are referring to the ability of neurons to form new connections (synapses) with other neurons. This occurs at the level of the dendrites, fine branches that sprout out from the neurons. These dendrites have “spines” which can develop into the new synapses, These synapses are formed and lost, as part of normal rewiring of the brain.

When we are learning new information, the neurons are actively forming new synapses. However some neural pathways or connections become redundant and without use or stimulation, these synapses simply get resorbed. This then frees up more space for yet more new connections to form, so it’s a great system.

The part of the brain we use for our higher level of thinking such as planning, organising, decision-making and our working memory is the prefrontal cortex. This is the part of the brain that is the last to fully mature in humans and is the area most likely to be affected by the effects of ageing.

High levels of stress and cortisol are known to cause neurons to shrink and for synaptic connections to be lost. Fortunately, once the stress is removed, our plastic brain allows new synapses to reform.

The effect of ageing on our brains plasticity.

New research from the Mount Sinai School of Medicine has shown that the brains of middle aged and elderly rats were less able to adapt to a behavioural stress response. In other words they were less able to learn from the experience. The neurons of the younger rats did change, showing normal plasticity and rewiring. Previous studies in 2010 examining the effect of the stress response in older rat brains had found a lack of a plastic response here as well.
Does this mean that stress doesn’t affect us as much as we get older? No, it means that with age, we lose some of our resiliency to stress; our brain is less able to respond, or to produce new synapses after the stress has been removed.

Our somewhat fragile and demanding prefrontal cortex is continually rewiring itself in response to all the stimulation and experience it encounters every day. Like plastic bottles however, our level of plasticity appears to diminish with age, we become less able to respond to either learning or stress.

With brain fitness training we are encouraged to “use it or lose it.”
To keep our mental sharpness and brain plasticity, it appears essential we continue to provide our brain with a variety of new and challenging activities.

Ref:
E. B. Bloss, W. G. Janssen, D. T. Ohm, F. J. Yuk, S. Wadsworth, K. M. Saardi, B. S. McEwen, J. H. Morrison. Evidence for Reduced Experience-Dependent Dendritic Spine Plasticity in the Aging Prefrontal Cortex. Journal of Neuroscience, 2011; 31 (21): 7831 DOI: 10.1523/JNEUROSCI.0839-11.2011

When we feel good about ourselves, the assumption may be that we are actually healthier. But is this actually true?
Do positive emotions really make a difference to health outcomes especially as we age?

How we approach ageing, stress, pain or illness can make a huge difference in determining the quality of the life we lead.
So does positive thinking help us to engage in healthier activities and enable us to remain proactive in keeping healthy?

Meditation has been shown in studies to produce ongoing positive improvement in cognition, memory and mood stabilisation.

The technique of mindfulness training teaches a person the ability to deal with a challenge or situation by removing any emotional baggage or judgment attached. This then enables the person to become more aware of their present sensations, feelings and state of mind, to look at a possible solutions and make a decision based on clear, focussed thinking.

This technique has been found to be so effective that the US army has used mindfulness training for new recruits who are facing deployment to Afghanistan or Iraq.

It had been previously shown that experienced meditators (compared to non meditators) showed thickening of the cerebral cortex in those areas of the brain associated with attention and emotional integration.But not that these changes had been produced by the meditation.

A new study has now shown a beautiful example of the brain’s plasticity at work.

A small group of 16 people engaged in an 8-week mindfulness meditation program to reduce stress. They underwent MRI brain scans two weeks before and at the end of the program.

The researchers from Massachusetts General Hospital found two things:
• the group reported feeling better as a result of the meditation,
• actual physical and measurable structural changes were shown in the associated brain areas not seen in the control group

This supports the idea that we can increase our actual well being through this technique.

Over the 8 weeks, the group met weekly for practice of mindfulness meditation and in addition spent 27 minutes every day practising mindfulness meditation exercises.
The results from the scans showed increased grey matter density in the hippocampus (the area of the brain associated with memory and learning) and in areas associated with self-awareness, compassion and introspection.
Conversely in the amygdala, the area of the brain linked to anxiety and stress there was a corresponding decrease in grey matter.

So yes, our plastic brain can change using mindfulness meditation, to increase our actual well being through this technique.

This opens the door to look at whether this type of meditation could provide useful and effective treatment options for those living with other stress related disorders such as PTSD (post traumatic stress disorder)

Refs:

January 30 issue of Psychiatry Research: Neuroimaging,
Sara Lazar, PhD, of the MGH Psychiatric Neuroimaging Research Program

A. Ong Current Directions in Psychological Science journal of the Association for Psychological Science

It’s Friday night, it’s been a huge week, you are exhausted and just looking forward to getting home. The last thing you want to do is think about cooking dinner. The thought of just putting your feet up, maybe watching a movie and ordering takeaway becomes really attractive. When we are stressed, our emotional drivers are likely to lead us to eat high fat foods such as pizza and ice cream.

Dieting is a stress too.
Have you ever been on a crash diet, successfully lost some weight only to find that it all goes back on (with a little extra!) in a relatively short period of time?
Though if we continuously starve ourselves over an extended period of time, this restriction of calories or kilojoules will actually lead us to live a longer life (just hungry). There are people in the world actually experimenting on themselves to achieve this. I’m not suggesting you do too.
Most if us choose not to live with calorie restriction. Life is meant to be enjoyable too isn’t it? Unfortunately if you have some excess kilos you want to lose, your experience is more likely to be one of the merry-go-round of weight off, weight on, weight off, weight on.
It is this type of dieting stress, which alters our brain.

Researchers at the University of Pennsylvania put a group of mice on a diet for three weeks. They lost weight. They also showed increased levels of stress hormones and displayed depressive behaviour. An epigenetic* change was noted and that this change persisted even when the mice went back to a normal diet.
The mice were then subjected to stress, which resulted in them choosing to eat higher fat mouse food compared to a control group who had not previously dieted.

This outcome suggests that in humans, dieting alters our brain, making it not only more difficult for us to lose weight in the first place but also reprograms our brain on how we deal with future stress and our emotional food choices.

So in order to lose weight successfully, it comes back down to healthy food choices and exercise.

Have you noticed it’s Friday today? How are you going to respond to “what’s for dinner tonight?”

• In epigenetics, an experience can alter the form and structure of the DNA in certain genes.

Ref: Society for neuroscience (2010, Dec 1) Yo-yo dieting alters genes linked with stress