Ever heard the brain referred to as your thinking organ or command center?

While it’s true that the brain enables higher-level processes that distinguish us from other species, its primary role is much more fundamental: keeping you alive.

Just as your heart pumps blood without your awareness, your brain runs a continuous, behind-the-scenes operation. It anticipates what your body will need, predicts what might happen next, and prepares responses before you’re aware there’s something to respond to. 

This process is known as predictive regulation. At its core, your brain works to maintain homeostasis – an internal state of balance and stability. It anticipates your body’s needs such as glucose, oxygen, water, and safety, and works to satisfy them before they become urgent. Think of feeding a newborn every few hours before they begin to cry from hunger. The brain operates in much the same way: proactive, not reactive. 

From this perspective, thoughts, emotions, and attention are not random – they are tools your brain uses to regulate your body and maintain survival.

Understanding this reframes how we think about trauma. Rather than viewing trauma responses as malfunctions, we can recognize them as adaptations – responses shaped by previous experiences that were once necessary for survival. Emotions such as fear, anxiety, and hypervigilance are not random outbursts; they are predictions informed by prior learning. 

Healing, then, is not “fixing a broken brain.” It is updating the predictions of a brain that has been doing its job – protecting you – based on outdated information. 

To understand how the brain carries out this work, we need to begin with its most basic building blocks.

The Cellular Makeup of Your brain

At the most fundamental level, the brain is composed of specialized cells called neurons. Each neuron forms between 1,000 and 10,000 connections with other neurons, resulting in an estimated 100 trillion or more synaptic connections. 

It is this density of connections, not the number of neurons, contributes to the complexity of human cognition and behavior. 

Each neuron consists of three primary components:

Neurons communicate using a combination of electrical and chemical signals. When a neuron activates, it sends an electrical signal down its axon. At the end, that signal triggers the release of neurotransmitters—chemical messengers—that cross a tiny gap (the synapse) and bind to the next neuron.

These neurotransmitters can have different effects. Excitatory neurotransmitters increase the likelihood that the receiving neuron will fire, while inhibitory neurotransmitters decrease that likelihood. Because neurons receive input from many other neurons simultaneously, they must integrate these competing signals. If excitatory input outweighs inhibitory input, the neuron fires; if not, it remains inactive.

This constant integration allows the brain to process information and respond dynamically.

trauma changes the brain

When we say trauma “changes the brain,” we are primarily referring to changes in how neurons connect and communicate. These changes are made possible by neuroplasticity – the brain’s ability to reorganize itself in response to experience. 

Neuroplasticity can involve strengthening or weakening connections between neurons, forming new synapses, pruning unused ones, generating new neurons, and growing new branches to expand communication networks. 

One of the most well-known ideas in neuroscience sums it up well: “neurons that fire together, wire together.” When neurons repeatedly activate simultaneously, their connection becomes stronger and more efficient. 

As a result, your brain constantly is shaped by what you experience and what you repeatedly pay attention to – and this doesn’t stop in adulthood. 

Just as trauma can wire in patterns of fear or hypervigilance, new experiences can wire in patterns of safety, connection, and regulation.

That’s what makes healing possible. 

Therapy, supportive relationships, somatic practices, and even sleep all help create new experiences for the brain to learn from. Over time, those new experiences can update old predictions. 

So recovery isn’t something separate from how the brain works – it’s actually the brain doing exactly what it’s designed to do: adapt, learn, and update based on what it experiences.