Brain's Unsung Heroes: The Remarkable World of Glial Cells 🧠

How Glial Cells Can Help Heal Trauma's Hidden Wounds (8min read/listen)

TL;DR Summary:

• Glial cells, once considered just brain "glue," are crucial for healing from trauma, maintaining homeostasis, and supporting neurons.

• Different types of glial cells, such as astrocytes, microglia, and oligodendrocytes, have unique roles, from forming the blood-brain barrier to facilitating neuron communication.

• Astrocytes protect neurons and help repair the blood-brain barrier, while microglia serve as the brain's immune system and are key to learning and memory.

• Oligodendrocytes create myelin for neuron insulation, aiding in efficient signal transmission, essential for brain recovery processes.

• Peripheral glial cells like satellite cells and Schwann cells help regulate the nervous system's response to stress and assist in nerve repair.

• The study of glial cells offers promising new insights for treating Complex PTSD and trauma, suggesting future personalized medical interventions based on individual glial profiles.

What Are Glial Cells?

In the vast expanse of the human brain, amidst the electrical storms of neuronal communication, lies an often-overlooked network of support: glial cells.

These cells once thought to merely be the "glue" of the nervous system, are now recognized as pivotal players in the brain's ability to heal, particularly from the sort of complex trauma that survivors of abusive relationships endure.

Glial cells are some of the deepest research I’ve done on the brain, they’ve fascinated me from the minute I learned about them.

It always made sense to me that the most complex thing in the known universe, the brain, would have an entire team of helpers at its disposal.

As it turns out, it does, which is exactly what we’re going to be talking about today.

Let’s dive in.

Glial Cells: More Than Just Brain "Glue"

Glial cells have traditionally been overshadowed by neurons in brain research, but these cells are now known to do much more than support.

They are critical in maintaining homeostasis, forming myelin, and providing protection and nutrition to neurons.

There are different types of glial cells, including astrocytes, microglia, ependymal cells, and oligodendrocytes in the central nervous system.

The peripheral nervous system has some of its own as well called satellite cells and Schwann cells.

Each has a unique role in brain function and health, let’s break them down!

Astrocytes: The Protectors and Healers

Astrocytes are star-shaped cells that perform a variety of tasks.

Most notably, they are responsible for creating the blood-brain barrier (BBB).

Blood is a neurotoxin, it hyper excites neurons until they explode, which isn’t good.

Astrocytes sit between our blood, and our brain to extract the nutrients our neurons need, without overwhelming them!

Not only that, but they also help repair the blood-brain barrier and reduce oxidative stress, which can be elevated due to the chronic activation of the stress response.

They are also involved in synaptic regulation, influencing the communication between neurons—a crucial factor in the rewiring of the traumatized brain.

Microglia: The Brain's Immune System

Microglia act as the first and main form of active immune defense in the central nervous system.

They are my favorite of all of the glial cells.

Not only do they act as the immune system of the brain, they are very important for learning and memory as well!

They help the brain prune unnecessary synapses and facilitate the formation of new connections—essential in the learning and adaptation that comes with recovery.

Following trauma, microglia can become overactivated, sometimes causing inflammation that might contribute to the symptoms of Complex PTSD.

When you hear the term “neuroinflammation” it’s glial cells that are most likely at the center of what’s going on.

Just like the immune system in the rest of your body, inflammation can be an adaptive way to heal damaged cells, but as it becomes chronic, you start to run into a multitude of issues.

There’s also research connecting microglial to all sorts of neurodegenerative diseases like Alzheimer’s, Parkinsons, Huntinings, MS, and more.

Oligodendrocytes: Facilitators of Communication

Oligodendrocytes are responsible for creating myelin, the fatty substance that insulates neuronal axons, enhancing the speed and efficiency of electrical signal transmission.

I’ve found it easiest to think about these bad boys as duct tape around a water hose with lots of holes poked in it.

When you run the hose with lots of holes in the tubing, water escapes through all the holes, so the stream at the end is very weak.

When you wrap the tubing with duct tape, covering the holes, the stream at the end strengthens.

This is what myelin does to neurons, the neuron is the hose, the axon is the tubing, and the myelin is the duct tape!

In the healing brain, remyelination can be critical as it allows for more rapid and efficient communication between neurons—vital for the processes of learning and the re-establishment of a sense of safety.

Ependymal Cells: Cerebral Aqueducts and Healing Streams

Ependymal cells are one of the lesser-known glial cells in the central nervous system (CNS), yet they hold a significant role in maintaining brain health and function.

These ciliated cells line the ventricles of the brain and the central canal of the spinal cord, forming a thin membrane.

The primary function of ependymal cells is to produce and regulate the flow of cerebrospinal fluid (CSF), which cushions the brain and spinal cord, provides nutrients, removes waste, and acts as a conduit for signaling molecules.

Ependymal cells can also interact with immune cells, my good friend the microglial.

They may help modulate inflammation following traumatic brain injury, which is critical for healing and preventing secondary damage.

Peripheral Glial Cells: Satellite Cells and Schwann Cells

While much focus is given to the central nervous system (CNS) when discussing brain trauma, the peripheral nervous system (PNS) also plays a pivotal role in the body's stress responses and overall well-being.

Satellite Cells: The Regulators of the Peripheral Nervous System

Satellite cells envelop the neuronal cell bodies within the ganglia of the PNS.

This is a fancy way of saying that the neurons of your body need cells to protect them just like the ones in your CNS do.

That being said, satellite cells regulate the chemical environment around neurons, much like astrocytes in the CNS.

For survivors, this regulation is vital since the PNS connects the brain to limbs and organs, coordinating the body's response to stress and relaxation.

Schwann Cells: Architects of Recovery in the PNS

Schwann cells are responsible for the myelination of neuronal axons in the PNS, aiding in the rapid transmission of electrical signals.

Just like oligodendrocytes do this in the CNS, Schwann cells do it in the PNS.

They also play a crucial role in the repair of nerves outside the CNS.

If a nerve is damaged, Schwann cells can help to regenerate the axon and restore function.

For someone who might experience physical symptoms related to their trauma, such as numbness or pain, the regeneration of nerve tissue facilitated by Schwann cells could be critical.

Healing in the PNS can mean not just emotional recovery but also the alleviation of physical symptoms that are psychosomatic manifestations of trauma.

What Do Glial Cells Have to Do with Trauma?

The connection between glial cells and the symptoms of Complex PTSD (CPTSD) or trauma is an emerging area of research, and while direct causality is often difficult to establish in neuroscience, there is a growing body of evidence suggesting that glial cells play a significant role in the brain's response to trauma, which could relate to the symptoms experienced by individuals with CPTSD.

Here are some ways in which glial cells may be implicated in the manifestation of trauma-related symptoms:

Neuroinflammation

Glial cells, particularly microglia, are involved in the brain's inflammatory response.

Studies have shown that chronic stress and trauma can lead to a state of sustained neuroinflammation, where microglia become overactivated.

This inflammation has been linked to various psychiatric symptoms, such as mood disturbances and anxiety, which are common in people with CPTSD.

Neurotransmitter Regulation

Glial cells are also involved in the regulation of neurotransmitters.

Dysregulation of neurotransmitters like serotonin, dopamine, and glutamate has been implicated in the pathology of mood disorders and other symptoms associated with CPTSD.

Peripheral Nervous System

Satellite cells and Schwann cells in the peripheral nervous system may also be affected by trauma, which could explain some of the physical symptoms of trauma stored in the body, such as pain or somatic complaints often reported by individuals with CPTSD.

It's important to note that while these associations are supported by research, they do not necessarily indicate a direct cause-and-effect relationship.

Trauma and CPTSD are complex conditions that are likely the result of a multitude of factors, including genetic predisposition, environmental triggers, and psychosocial influences, with glial cells being one piece of the puzzle!

The Future of Glial Research in Trauma Recovery

The exploration of glial cells has opened a new frontier in understanding how the brain responds to and recovers from trauma.

The future of glial research holds promise for revolutionary approaches to healing, especially for individuals recovering from the effects of abusive relationships and associated trauma such as Complex PTSD.

The next wave of research could transform this understanding into actionable therapies and support mechanisms for trauma recovery.

Precision Medicine and Glial Cells

Future research may enable us to tailor interventions to the individual's specific glial cell profile.

For example, we might discover that certain types of glial cells respond more robustly to particular therapeutic interventions.

By mapping out the glial responses of a person, we can personalize medicine to target the most responsive areas, enhancing recovery rates and reducing the time it takes for survivors to feel whole again.

Glial Biomarkers for Trauma

Emerging studies may identify specific biomarkers within glial cells that correlate with trauma responses.

These biomarkers could become the key to assessing the severity of a person's trauma and the brain's state of healing.

They would provide concrete data that could guide the therapeutic process and measure the effectiveness of different treatment modalities.

Integrative Approaches for Comprehensive Care

Finally, the future of glial research could inspire a new framework for integrative care, where neuroscientists, psychotherapists, and coaches collaborate more closely.

By combining cutting-edge science with compassionate therapy, we can create a nurturing environment for survivors, one where the biological and psychological aspects of healing are addressed in unison.

This is the ultimate vision I have for Mind, Brain, Body Lab, in fact!

I believe connecting all of these disparate areas and integrating technologies like AI and data science into them would help us heal more people.

A Glial-Inspired Vision for Healing

As we learn more about these guardian cells of the brain, we open up possibilities for treatments that are not only effective but also gentle and attuned to the complex needs of those recovering from the profound impact of abusive relationships & traumatic childhoods.

The future looks bright, with glial cells guiding the way toward a deeper, more compassionate understanding of trauma and recovery.

I hope you found today’s topic as interesting and exciting as I do, and until next time… Live Heroically 🧠

Supporting Research:

• Abbott, N. Joan, Lars Ronnback, and Elisabeth Hansson. "Astrocyte–endothelial interactions at the blood–brain barrier." Nature Reviews Neuroscience 7.1 (2006): 41-53.

• Kettenmann, Helmut, et al. "Physiology of microglia." Physiological reviews 91.2 (2011): 461-553.

• Paolicelli, Rosa C., et al. "Synaptic pruning by microglia is necessary for normal brain development." science 333.6048 (2011): 1456-1458.

• Baumann, Nicole, and Danielle Pham-Dinh. "Biology of oligodendrocyte and myelin in the mammalian central nervous system." Physiological reviews 81.2 (2001): 871-927.

• Hinwood, Madelyn, et al. "Evidence that microglia mediate the neurobiological effects of chronic psychological stress on the medial prefrontal cortex." Cerebral cortex 22.6 (2012): 1442-1454.

• Fields, R. Douglas, and Ben A. Barres. "Glia: The Brain’s Other Cells." (2022): 354-362

• Hiremath, Madhav M., et al. "Precision medicine for traumatic brain injury: current status, challenges, and potential solutions." Frontiers in neurology 11 (2020): 912.

• Bigler, Erin D., and Amy Siegel. "Traumatic brain injury and glial biomarkers: Perspectives for precision medicine." Frontiers in Neurology 12 (2021): 1053.

• Kumar, Rajiv G., et al. "Glial fibrillary acidic protein is elevated in superior frontal, parietal and cerebellar cortices after traumatic brain injury in rats." Neurochemical research 35.12 (2010): 2057-2064.

• Olivera, Anlys, et al. "Peripheral total tau in military personnel who sustain traumatic brain injuries during deployment." JAMA neurology 72.10 (2015): 1109-1116.

• Nijenhuis, Ellert RS, and Onno Van der Hart. "Forgetting and reexperiencing trauma." (2011): 339-360.

• Gupta, Madhulika A. "Review of somatic symptoms in post-traumatic stress disorder." International Review of Psychiatry 25.1 (2013): 86-99.