The Neuroscience of Being 'Us' - Part 2 How threat and unresolved emotion changes the brain

Interactions between the cortex (frontal lobe) and limbic system; the anterior cingulate and insula

(Part 2 of a 2 part series see here for part 1)
There is another important part of the mid-brain (adjacent to the amygdala) that has a function in registering threat and helping to lay the foundations of trauma. It’s called the Anterior cingulate cortex (ACC) and is important as a filtering system. It is another part of the brain that is functionally degraded as a result of trauma. It possesses structures called spindle cells which wrap around the nerve bundle of fibres linking the left to the right sides of the brain. These connections between left and right may be very important for how emotions are integrated and the meaning made of the emotional events in our lives– and it may be key to why techniques such as EMDR which stimulate better integration allow re-wiring to occur .

The Anterior Cingulate Cortex ACC is primarily involved in fear conditioning as it normally inhibits the amygdala, which as we know is the primary area for threat encoding. However, it also appears to play a role in emotionality, selective attention, and certain social functions, including emotional attachments and parenting, as well as generation of the concept of the self in relation to society. It is my contention that this is the part of the brain that fails in attachment disorder, and other more chronic relational trauma disorders. I have particularly noticed that the sense of self is often highly distorted, even in very outwardly functional people. They operate despite their own self-loathing to become very respected/hard-working/ achieving people but when questioned they cannot see that anything they have done has any worth. If you press them they will acknowledge grudgingly that it might have value but they do not feel that emotionally, it is more of an intellectual awareness. The ACC might be the part of the brain that we bring ‘online’ in trauma treatment, as when we do EMDR. We rewire the responses by a process of extinguishing the conditioned response of self-hating or limiting. I will discuss this within the tools section.

The insula (another part of the cortex just behind the PFC) is an area that helps interpret incoming sensation, rating it dangerous or not. It is highly involved in our subjective experience of pain, for example, and can become active just by imagining pain as well as in more pleasant experiences like music appreciation. It monitors incoming signals from the body (particularly the physiological experience of emotions like sadness, fear, anger, etc) and combines this information with the limbic system and brainstem to generate appropriate responses. As we will see later, when the signals get scrambled by unresolved emotional memory, stress is able to overwrite any inhibitory stimulus and most incoming signals are interpreted as painful, dangerous or life-threatening, causing all sorts of chronic pain and stress-related diseases.

Left and right sides; the Corpus callosum connection

Despite the fact that the cortical structures are split into left and right hemispheres, the brain remains undivided at the level of the lower reptilian brain structures - sometimes referred to as the ‘subcortical bridge’ In treatment, the client and therapist may also be able to capitalise on this. Nonverbal information, including “unconscious or preconscious codes, nuances we can never attach a name to,” cross most readily (Austin, 1999) . Using somatic experience as an entry point in therapy and maintaining mindful awareness of the body may facilitate information processing by enhancing information transfer between the hemispheres. This is what is aimed for in clinical hypnotherapy intervention by engaging the imaginative right hemisphere. However, there is controversy in hypnotherapy as to the nature of hypnosis as we have already shown with regard to whether it is a state separate from normal everyday experience or not. This was developed further by the great hypnotherapist and psychologist Pierre Janet.

We have already intimated that in subjects with PTSD and other lesser traumatically encoded states, the amygdala may become hyperactive towards “a generalisation of the fear response” or conversely underactive which “may allow continued functioning in situations characterized by ongoing threat” such as that experienced by a child who is under threat from their caregiver. That this may be in part to do with the alteration in function of the left and right hemispheres and specifically their inter-communication is an ongoing debate with psychotherapy.

This is an extract from my book The Scar the Won't Heal - available now on amazon. In the next instalment I look at Interactions between the cortex and the limbic system.

The Neuroscience of Being 'Us';Part 1 The cortex and emotion

The region of the brain called the prefrontal cortex (PFC) is really what defines us as human; it is crucial for how we pay attention, it enables us to put things in the ‘front of our mind’ and hold them in awareness. It is the basis of our moral system and capacity for empathy. Studies of people who have suffered injury to the PFC show us that it is an important brain area for creating our ‘map of the world’ i.e. the mental representation of our outer experience. Various different parts of the cortex have specific functions:

The Pre-Frontal Cortex (PFC) regions in the two hemispheres

• The Medial Pre-frontal Cortex (MPFC) is the integration centre involved in coordinating left and right sides with direct connections to the amygdala in the limbic system. This part is involved in our sense of curiosity and awareness and is the part that we target in therapy particularly for dissociated clients who have lost connection with their bodily self. It is activated during mindfulness meditation, mindful awareness or psychotherapy.
• The Dorso-lateral Pre-frontal cortex (DPFC) is the site of our short-term or working memory and has no direct connection with the limbic system. It is the last bit to develop in the human and often the first to go with ageing. We’ve all had the experience of walking into a room and forgetting why we went there – this is a failure of this part of the brain to hold the requisite information for long enough for us to commit it to longer term memory.
• The Right Orbital Pre-frontal cortex (ROPFC) (so called because it is directly behind the right orbit of the eye) is most specifically concerned with emotions and arousal regulation as it has good connections with the limbic system and can inhibit activation (this is important in trauma therapy). It develops early in life and is the social centre of the brain, which, if given support and trusting relationships in those early years, becomes more capable of regulating emotion but it depends on good parental attachment (Shore, 2007) . It becomes our 'soothing centre' if promoted by secure attachment. Self-soothing or auto-regulation is very important for subsequent adult emotional regulation. If childhood experience failed to develop this part of the brain a pattern of dysregulated ‘up and down’ or entirely absent emotions results. Our prisons are full of such people where auto-regulation has never been learnt successfully.

Through its links with the limbic system, and the immune system (via regulating levels of cortisol in the HPA axis), the PFC acts as the interface between mind and body and so is implicated in such medically unexplained conditions such as fibromyalgia, whiplash or pelvic pain. These could be construed as the body’s way of expressing emotions through pain; this is termed somatisation. Defined as feeling emotions through the body rather than as feelings, these issues are common in people “in whom emotion is undifferentiated and unregulated” (Shore) . In other words they can’t tell one emotion from another and they may find it difficult to put words to feelings; memories may also be completely dissociated from feelings. This is common after trauma – particularly attachment trauma. The brain gets confused as to what the input represents and may conflate pain with the emotional pain of betrayal/abandonment – they share many of the same pathways.

I met one such person who was on a training course with me. He described some awful events that happened in his childhood without emotion of any kind. He was suffering from this condition, termed alexithymia, (an inability to describe emotions with words) which could be seen as a failure of the ROPFC. Somatisation is not a commonly understood concept in conventional medicine although, in fact, it lies at the base of many of the chronic pain syndromes I am exploring in this book. It is a direct example of how poor relationships and unexpressed emotions make us ill.

The cortex is known to go ‘offline’ in the aftermath of trauma which may explain the sudden switches from hyper to hypo arousal of conditions such as PTSD and other trauma related conditions. As the cortex is normally the modulator of experience, helping to bring logic and a ‘wider view’ its failure to inhibit the limbic system prevents such fine tuning of curiosity and reason. In trauma work we often talk about ‘getting curious’ as the antidote to these limbic states. We need to engage people in what happens when they think a certain thought or act a certain way, enabling them to tune in to their body states – something that they may have actively blocked from childhood onwards. When they begin to look at their reactions as symptoms (i.e. “I've been triggered and this is my survival brain in charge”) and not from an underlying pathology (i.e. I’m mad, bad or weak), they begin to see how extraordinary the human brain is and their curiosity (MFPC-mediated) is aroused . This is a direct antidote to the dissociation and emotional dampening that many people suffer after a traumatic experience. It is the direct target of intervention, whether by linking the two sides of the cortex as in EMDR or by hypnotherapy and CBT whereby we engage the imagination and the thinking brain respectively. We cover these therapies in more detail in my website. Suffice to say no-one need suffer permanently; these states can be reversed as the brain is plastic (neuroplasticity).

This is an extract from my book The Scar the Won't Heal - available now on amazon. In the next instalment I look at Interactions between the cortex and the limbic system.

The gut brain - strangely true

The gut is not just the site of your digestion it is also a key part of your immune system and the site of a good deal of the information relayed to and from your brain. It has even been called the ‘second brain’ or ‘enteric brain’ as it contains 100 million neurons i.e. more neurons than the spinal cord or peripheral nervous system combined[i]. It is responsible in no small part for how you feel; your mental state, mood and health. For instance, 95% of the feel-good chemical serotonin in your body is found in your gut. This fact has been suggested as the reason why many mental diseases have correlates in the gut e.g. autism and depression often have gut symptoms associated with them.

Vitally, via the roughly 100 trillion bacteria that it contains[1], called the gut microbiome, it contains enough bacterial DNA to produce a vast array of the metabolic products (vitamins, neurotransmitters, enzymes, and signaling proteins called neuropeptides) that our body needs to function. It has been said the human being is simply a highly evolved, complex host for bacteria  In fact, evolution has shown us that bacteria have often been instrumental to the development of the organism, as they have developed in symbiosis with us[ii]. Babies born via Caesarian section often have poor gut function as they have not been properly inoculated with their mother’s gut flora via a vaginal birth[iii]. This may cause the children to have more allergies and health issues than children born normally, including mental health problems. Given the increasing use of C-section in hospitals, and the likelihood of deficiencies being passed on from  that child when she too has baby, this has health implications for us as a society not just as individuals.

The importance of the gut in general health is often ignored. Nutrition is mostly ignored when you engage with conventional medicine. How often has your doctor asked you about your diet when discussing your mental  – or even your physical - health[2]? Having a good balance of gut flora is vital – I am not looking at purely psychological factors here as I am only too aware that the balance of your gut microbes is crucial to your mental functioning. Your gut microbiome balance is vital to functioning. Unfortunately as your microbes get more out of balance, your digestion becomes poorer, you intake less vital nutrients and your gut gets further depleted and imbalanced. Opportunistic bacteria and resident yeasts begin to take hold. Symptoms are gas, bloating, itchy, flaky skin, cravings for sweet foods, and ‘foggy’ brain. You can see it is a cycle: poorer digestion – less nutrients and higher yeasts – poorer digestion.

Figure 1 Digestive tract and immunity

 

Let’s look at one example of how this works. The gut is one of the most important sites of  your immune system – the gut wall is, after all, a form of modified skin and as such is an entry point of pathological microbes (i.e. the unfriendly type!). Hence it’s not surprising that the most evolutionarily ancient immune function (called the ‘innate immune system’), is based here. It is the essential non-specific first-line defence to invasion controlled by the release of inflammatory molecules called cytokines. These are peptides (small proteins) produced in the body which control inflammation. Continuous stimulation by bacterial structural cell wall sugars called lipo-polysaccharides activate the immune system to be in a state of constant alert, helping to keep it activated. Bacteria keep us primed!

The release of cytokines is controlled by the balance of these polysaccharides and it helps the body maintain its immunity and, via their or its interaction with the stress response, even its normal sleep pattern (they are involved with the transition to Rapid Eye Movement sleep from non-REM sleep). This is important for dreaming and restful sleep. So, the balance of your gut flora influences your immunity and the quality of your sleep; therefore both directly and indirectly affecting your health using bi-products of their metabolism. This leads to the perhaps surprising conclusion that bacteria are essential to our physical wellbeing.

However, they also govern the balance in your mood and anxiety levels via the serotonin and other neurotransmitter levels they produce. Surprisingly most of the serotonin in your body is found in your gut. This is why when we increase levels via anti-depressants (the SSRIs like Prozac reduce re-uptake) you often get gut problems as a side-effect; oo much serotonin is just as much of a problem. So gut flora are vital for mental health too.

Another factor influenced by your gut bacteria is the permeability of your gut. With a standard western diet (also called the ‘standard American diet’  (SAD) in the US), your ‘bad’ bacteria are encouraged to overgrow which can cause the cells in your gut to become ‘leaky’ i.e. the gaps between the cells instead of having ‘tight junctions’ as normal, develop gaps. If you were unlucky enough to have childhood infections and were then prescribed extensive antibiotics these can affect gut flora for life too and exacerbate the problem. Antibiotics are non-selective about which bacteria they kill – the same is true of ‘anti-bacterial’ handwashes which are highly damaging to the gut.

Toxic bacterial overgrowth can encourage auto-immunity as undigested protein fragments (peptides) and toxins are able to penetrate through the gut wall causing the body to react with an immune response to food as if it were an invader. The cells in the gut are meant to be a semi-permeable barrier, finely controlled so as to only allow certain things in. When this control fails by the cells being permanently open, the barrier is broken and disease may result. Excessive permeability has been implicated in such definitive auto-immune conditions as diverse as coeliac disease, multiple sclerosis and chronic fatigue syndromes.

So, leaky gut syndrome is a precursor to many diseases as the gut is key in regulating so many bodily functions. In addition to the direct effects on immunity and inflammation, there are more factors in gut functioning that impinge on your health. The short-chain fatty acids (breakdown products of indigestible carbohydrate in your diet produced by your gut bacteria) are epigenetic regulators[3]; that is they help to control what genes are expressed in the cells. These epigenetic effects of the gut flora help to explain why each of us reacts differently to our environment – since each of us has an individual gut flora we have a unique response to the external environment. Those with a healthy gut not only have a healthier immune system but digestion and metabolism work better, with more nutrient availability, more accurate genetic regulation and intercellular communication. It can’t be overstated how important this is for brain function, especially in the area of pain response.

Although we are all familiar with the idea of ‘gut feelings as a source of information, we are seldom aware how vital the gut is in central nervous system (CNS) function. The enteric (gut) brain really does exist and it is just as important as the brain in your head. Stress (whether conscious and acute, or unconscious and chronic) alters the balance of your gut flora via the release of hormones like adrenaline and cortisol (from the adrenals) and cytokines produced by bacteria. The self-regulating system is sent haywire and the results are systemic (i.e. throughout your body). These findings are so important, the study of these interactions now has its own field

This is an extract from my book Stress, Trauma and Unresolved Emotion in Chronic Disease.

 

See here to purchase copies (digital or paperback)

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[1]10 times the amount of cells in your body! The combined gut flora has been called the ‘third brain’. Gut and brain start off as the same tissue embryologically. They then differentiate into central and enteric nervous systems. The enteric nerve cells are considered part of the autonomic nervous system in some newer definitions, see polyvagal theory later in the book. Brain, Gut, Microbes; First Second and Third brain.

[2] While writing this book I had a free GP health check organised by the NHS. The nurse did not physically assess me (apart from to weigh me and take a blood test). She asked a little about my diet and exercise but it was very general and no advice was given to reverse my hormone imbalance.. What an opportunity missed to educate people about health.

[3] ‘Above genetics’. It means there is another layer of control above what DNA you have. It is a very exciting development in biology. See the epigenetics section for more information.

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[i]Hadhazy, Adam.(2010). Think Twice: How the Gut's "Second Brain" Influences Mood and Well-Being. Scientific American. February 12

[ii] Yatsunenko, et al. (2012). Human gut microbiome viewed across age and geography. Nature, 48 6(7402), 222–227. doi:10.1038/nature11053

[iii]The Human Microbiome: considerations for pregnancy, birth and early mothering. January 2015 http://midwifethinking.com/2014/01/15