The Amygdala aka our Excitable Friend - Part 1

The brain. Honestly it blows my mind (no pun intended).

Let me introduce you to your overpowering friend, you know the kind, you need them in your life but better in small doses.

Welcome, the amygdala. Sometimes described as the ‘alarm bell’ or ‘smoke detector’ of the brain. The amygdala is part of the limbic system and drives our fight and flight response. When a threat arises (based on sound, image or body sensation) it perceives the level of threat based on previous experiences communicating with various brain structures deciding whether to fight or flee. Now when everything is working harmoniously it responds to the threat by messaging the hypothalamus to release stress hormones to mobilise our body to take action and when the threat is over our body returns to normal.

When we take what we call effective action, i.e. we respond to the threat by fighting or fleeing, our body has done its job, it has responded effectively and can return to its resting parasympathetic state. During stress adrenaline is immediately released, followed by cortisol for a more prolonged threat; our heart beats faster, our blood pressure whooshes up, blood and oxygen rushes to our brain and muscles to mobilise the body to take effective action and once the threat has dissipated everything slows down and blood and oxygen gets redirected back to our digestive and reproductive organs (which are considered secondary during our stress response). Another key factor here is glucose - during stress higher levels are released to our cells to allow the body to produce more ATP (energy) to respond to the threat. In chronic stress glucose levels stay high hence the link between stress and obesity. Stress in normal levels has its place, chronic stress is not our friend. 

The pandemic may naturally be heightening our stress levels and we may find the amygdala rings the alarm bell more frequently and to threats which are perceived worse than they actually are. Now this could be something fairly innocuous in normal times such as face to face meetings, passing people on the street and their proximity to you, chatting to parents at the school gates, calling your boss and so on, but during times of stress the littlest things that maybe wouldn’t normally bother us begin to and our amygdala keeps ringing that damn bell. When this happens this keeps our anxiety levels above where they may normally be.

Anxiety naturally goes hand in hand with stress, this is a usual reaction but becomes more overwhelming when it becomes a habit. I found it useful once when someone suggested labelling anxiety as something you have in reaction to a situation rather than labelling yourself as an anxious person. On the other hand many people naturally have anxious traits and understanding how the brain and body work together and paying attention to arising sensations can be helpful.

Back to the amygdala. It is located in our limbic system, one of the oldest parts of the brain (another being the brain stem), the part that comes on line the minute we’re born. As babies the amygdala is constantly being rung, we’re wet, hungry, tired and we need those needs met. The limbic system is our survival mechanism, our emotional brain. It’s involved in memory and learning, it’s where sensory data is received (via the thalamus) and sent on to the relevant brain structures to process and it's where the hypothalamus activates the stress response. The amygdala applies emotional significance to memories, including fearful ones hence its ability to perceive threat based on previous memories. When we feel safe and loved the amygdala is deactivated however in trauma it goes haywire. I’m not an expert (yet) but if you’re interested there is a fascinating book called ‘The Body Keeps the Score’ by Bessel Van der Kolk. Apparently 90% of us have experienced trauma and understanding our body that we inhabit is a pretty good inroad towards healing. 

To close. There’s always a party in our limbic system, sometimes it’s a small gathering, everyone’s excited but manageable and other times the party gets out of hand, raucous and overwhelming and that is when we need our responsible friend, the frontal lobe, specifically the prefrontal cortex (PFC) to get involved to calm things down. Easy right? The PFC gets more involved at the smaller gathering, keeping the party at a tempered level but once the party hits a certain high, the PFC is a distant friend and the tables switch; it’s the friend you desperately need but they’ve moved away and you no longer have that connection. 

My next blog is about our PFC, our relationship to it and why we need to keep that connection and how we can improve it.

Stay tuned…..