Archive for July, 2014


The Adaptive Brain

Our brain’s biological path is not set, rather its development is a highly adaptive process that responds to environment and experience. Our earliest experiences and environments occur at the same time that our brains are going through their most rapid stages of growth, so those earliest experiences and environments are critical to how the development of neural circuits adapt to what kind of environment we, as biological organisms, are expecting (prenatal) or experiencing (postnatal).

Prenatal environments (the womb) respond to maternal emotional states and maternal emotional states are dependent upon the mother’s experiences and environments. So what the mother is experiencing while carrying a foetus in the womb, affects the foetus’s development and adapts it to expect the kind of environment that the mother is perceiving and that the foetus expects to be delivered in to, both in terms of physiology and neurology. For instance, high levels of the hormone testosterone during pregnancy, produced as a response to aggression, has been implicated in autism. So repeated or prolonged aggressive episodes during pregnancy appears to have developmental consequences.

Postnatal environments take in a lot of factors, but are predominantly determined by parental interactions during the first few years. The relationship with parental figures, especially the mother, and the level of safety and nurture experienced in that relationship, determine relational patterns throughout the rest of life. If our earliest emotional bonds do not cultivate a sense of safety in making an emotional connection to someone, subsequent emotional connections throughout life will be subject to feelings of not being safe as the fear memory system triggers the amygdala and HP Axis in to a stress response, initiating fight or flight behaviours in response to attempts at genuine intimacy with another.

Early stressful environments cause areas of the brain associated with the fear response to receive a boost in developmental energy. So these areas grow faster, bigger and more dominant than they would in a safe nurturing environment. At the same time, areas of the brain that would normally moderate the fear response don’t receive as much developmental energy as they would have in a safe and nurturing environment. This means that things that shouldn’t cause a big fear/stress response, in fact do cause a fear stress response that the situation doesn’t really call for. As this fear/stress response is autonomous, when it is triggered it becomes very dominant in our thinking, feeling and perceiving. So we may perceive certain things far more negatively than those things actually warrant. Whatever caused the initial stress will be stored away in our emotional memories which will be autonomously triggered by reminders of the initial emotional wound.

Menstrual Problems

At any one time our bodies have a limited supply of available energy. There are complex biological mechanisms that determine how this available energy is made available to various processes. Experience and environment, both internal and external, both current and past, play a large part in determining how these mechanisms determine how and where they should make use of this limited available energy.

Homeostasis is the term used to describe when our body is working harmoniously and when it is in a restful and peaceful state. During Homeostasis, our biological and cellular maintenance tasks get an adequate supply of the available energy. They are constantly fighting against cellular damage and cell and gene mutations. For instance, the BRCA 2 gene, known as the breast cancer gene, and currently, also “The Angelina Jolie” gene, does not actually cause breast cancer, it fights against breast cancer. The reason the BRCA 2 gene has been associated with breast cancer is that the mutation means it is less effective at fighting breast cancer. This, however, is not how the media portrays the problem, preferring the sensational approach that paints the BRCA2 gene as some kind of monster that we should fear. Cortisol and the HPA Axis and their role in diverting energy to muscles as a response to stress, plays a part in how genes and cells mutate.

Stress interrupts homeostasis. Stress sends the signal that the muscles need all available energy via the HPA axis and the hormone cortisol. Cellular breakdown and mutation is going on in our bodies all the time and our biological maintenance systems will usually be working 24 hours a day cleaning up and maintaining cellular and biological health. Stress, however, reduces that available energy and reduces the effectiveness of our natural biological maintenance cycles.

Endometriosis is caused by cellular growths that should be going on inside the ovaries and fallopian tubes, actually growing outside the ovaries and fallopian tubes. This occurs even in healthy individuals. However, in healthy individuals, this dysfunctional behaviour of cells is usually well managed and quickly dealt with. But if our cellular maintenance is working with reduced efficiency, then this unwanted cellular activity is not managed as well as it might otherwise be, and this leads to continued growth that can lead to cysts and lesions on the exterior of the ovaries and fallopian tubes. These cysts and lesions then result in painful periods and other menstrual problems.

Reproductive Problems

The evolution of our stress response goes back to the dawn of evolution itself. Survival has been a biological imperative since the first creatures emerged on our planet and they began eating each other as a source of energy. The stress response grew out of the need not to be eaten so that the continuation of genes and species had the best chance of continuance. The stress response, as previously mentioned, mobilises all available energy to the muscles, it does this because the stress response is a survival response and to survive we need to evade and avoid anything that threatens to eat us because, throughout our evolution, that was the danger.

The stress system remains unchanged in us. It has had our entire evolution to develop and just because the need for it in our modern lives has reduced over the last few centuries does not undo millions of years of evolution.

Stress worked fine when we had to avoid a predator; we either escaped, fought off, or ended up being eaten by the predator. We only needed stress over a short period. Prolonged stress, however, is a product of our modern lives and is a biological disaster. Prolonged stress interferes with a host of biological processes.

However, reproductive problems go back to an earlier time when we still had to evade a predator. When your biology is screaming at you that your immediate environment contains danger then the last thing you want to do is bring a new life in to it. A new life will slow you down and that mean you are more likely to be eaten. And the new life itself will also likely be eaten. A lot of energy and time goes in to developing a new life, so that energy and time is not to be wasted and the biological cycles of reproduction are reduced, interrupted and put on hold by the stress response.

The active biological stress response says “Now is not the time to conceive and have a baby!”

That was all fine when the stress response was fleeting, but with our modern world we seem to have introduced new stresses that are prolonged and/or continuous and this can play havoc with our reproductive systems.

How the Stress Response can Become “Stuck On” By Traumatic Experience.

Traumatic experience, especially developmental traumatic experience, can cause the stress response to become “stuck on”, leading to hypersensitivity, hyper-arousal and hyper-vigilance.  This can be tested through saliva tests for levels of the hormone, cortisol. This maladaptive response can have long lasting, or even lifelong effects that disrupt reproductive systems throughout life. Our biological reproductive systems literally become set as default that our environment is too dangerous to allow ourselves to become pregnant and bring a new life in to that environment. Signals are sent to the womb and ovaries to reduce activity and even shut it down, menstrual cycles are interrupted and irregular. All biological processes are running at reduced efficiency; reproduction, digestion, cellular and organ maintenance, etc. Processes across our entire body are compromised by a biology that remains in constant readiness for “Fight or Flight”.

The modern implications for our reproductive system are;

Males:- Reduced sperm count, deformed sperm and low sex drive

Females:-Menstrual problems (pain and excessive bleeding), problems conceiving, problems producing eggs and low sex drive.

It is simply our biology, our stress response, doing the job that it evolved to do, but doing it in a way that is maladaptive and dysfunctional in our modern world.

It is our biology saying, “now is not the time to have sex and make babies because the environment we are in is not a safe one!”

A Further Complication.

If the stress response remains volatile yet conception is achieved, there can be a reduction in the nutritional quality and environment in the womb that can lead to a host of prenatal developmental problems; reduced birth weight, premature birth, developmental “disorders” (for instance; high levels of testosterone in the womb have been implicated in autism. Increased aggressiveness is associated with elevated levels of testosterone), miscarriages and other complications. In extreme cases, miscarriages can be almost immediate or occur within the first few days following conception.

 

Simon Attwood

Changing Brains