Recently in my online class, I learned about the different cells just within the CNS (Central Nervous System). For those of you thinking that we only had a one-part nervous system or just need a refresher course in biology, our nervous system consists of many parts. The main systems that we learn about in grade school are the CNS and the PNS. First, the CNS or the Central Nervous System, controls the brain and spinal cord. Second, the Peripheral Nervous System, controls everything outside of the brain/spinal cord. The microglial cell is a part of the CNS, which I will be discussing further in this topic.
Microglia cells are non-neuronal cells that are within our brain and spinal cord. The cells act as a special immune system by protecting the brain and removing debris that has been left over by dead neurons, also known as nerve cells. Since the cells act as an immune system, they respond much like how our body responds to the flu or the common cold.
Brain Injury and Microglial Cells
For example, swelling of the brain immediately comes to my mind when a brain injury occurs. Possibilities are endless when it comes to a diagnosis, such as a concussion, stroke, encephalitis, or even something as small as a headache. Much like when you scrape your arm on something sharp, you bleed and minutes later, the platelets in your body come rushing to the rescue and create a healing, protective barrier from the outside world.
The microglia cells do the same thing! They swell up when injured to protect the brain against any foreign invaders. Crazy? I think it’s pretty amazing!
When a person undergoes brain trauma or even the slightest of injuries to the head or spinal cord, the microglia cells are activated to respond quickly to the trauma site (Streit 2000). According to Streit and his studies, microglial cells aid the injured neurons by restoring them back to health, whereas a severely injured neuron cell will or can release a toxin to alert the MG cell to destroy it. Our bodies have a unique way in taking care of dying cells so that they can do no more harm or cause mutations.
In response to what I’ve learned in class about microglial cells and also through reading a few articles, it seems that even something as small as the MG cell, can have a huge impact on our brain and spinal cord in traumatic events. On occasion, we can lose brain cells from injuries, head-banging to our favorite rock song too hard, or dozing off to the laughing gas the dentist gives us, but we can always count on Robin (the microglia cells) to help restore or give a merciful death to our neurons, while Batman (the brain) stays focused on keeping us alive and well!
Please feel free to sound off down below in the comment section! I would love to hear your opinions/thoughts/ideas, etc. I also found a really neat video showing how microglial cells engulf neural debris (approx. 1 min. long).
Streit, Wolfgang J. (2000). Microglial Response to Brain Injury: A Brief Synopsis. Toxicologic Pathology, 28(1), 28-30. doi: 10.1177/019262330002800104