Amazing Facts About the Brain
Most people think of brain cells as neurons. While neurons are the main players in the brain, we have somewhere around 50 times more glial cells than neurons. Glial cells are simply non-neuronal brain cells.
While neurons transmit and receive electrical impulses, glial cells provide support and protection for neurons. Glial cells make myelin which are the insulating material of the axon of a neuron. Glial cells can make up 90% of the cells in the 3 pound mass that is our brain.
Interestingly enough, the genius Albert Einstein's brain did not have much more neurons than average. However, his brain did have much more glial cells than average.
Types of Brain Cells
There are different types of neurons depending on their shape. They include Purkinje neuron, Granule cell, Motor neuron, Tripolar neuron, Pyramidal Cell, Chandelier cell, Spindle neuron, and Stellate cell.
Just like there are different types of neurons, there are different types of glial cells classified as microglia and macroglia.
About 20% of glial cells are microglia. Microglia acts as the main immune defense system in the brain and central nervous system. They clean up debris by scavenging damaged neurons, plaques, and infectious agents and engulfs them in a process known as phagocytosis.
The different types of macroglia are astrocytes, oligodendrocytes, ependymal cells, radial glia, Schwann cells, Satellite cells, and Enteric glia cells.
Brain's Amazing Complexity
A single neuron may have anywhere from 6000 to 20,000 connections with other neurons.
Let's say a neuron have on average 10,000 connections with other neurons. And say we have 100 billion neurons. And they can transmit electrical impulses at 10 different levels of intensity. That means that that total number of potential brain states is greater than the total number of atoms in the universe.
Electrical impulse along nerve connection can travel at speeds of one mile per hour or up to 150 miles per hour.
Building of a Brain
At some point during gestation, the brain makes as many as 250,000 nerve cells each minute. DHA is require for the manufacture of these neurons.
At birth, the baby's brain contain about 100 billion neurons, that is roughly the number of star in the Milky Way galaxy. The size of the brain at birth is typically 350 grams. During the first year of life after birth, the brain nearly triples in size at over 1000 grams. This implies that the brain has not formed completely yet at the time of birth, otherwise it would be so big that it would not be able to come out.
Neuron connects with each other at synapses, or gaps. Neurotransmitter are chemical messengers that jump these gaps transmitting messages from one neuron to another.
Some of the neurotransmitters are ...
- Serotonin - affects mood, sleep, aggression
- Dopamine - for physical coordination
- Acetylcholine - for memory and activates muscles
- Glutamate - learning and memory and long-term potentiation (excitory)
- GABA - inhibitory neurotransmitter
- Epinephrine - regulates heart rate and fight-or-flight response
- Norepinephrine - stress hormone affecting fight-or-flight response
- Histamine - triggers inflammatory response as part of immune system
Mitochondria and Neurodegeneration
The brain weighs about 3 pounds. This is about 2% of body mass, yet it uses 20% of the oxygen and calories consumed by the body.
Needless to say the brain uses a lot of energy. What produces this energy? Mitochondria are organelles within cells that generate cellular energy known as ATP. Think of the mitochondria has the powerplants of the cells. Mitochondria dysfunction and oxidative stress are contributing factors in neurodegeneration (brain cell death). Almost without exception, our brains will shrink as we age. The most neurons we will ever have is at birth.
Although neurogenesis (the birth of new neurons) occurs mainly during pre-natal development, neurogenesis does occur in adults throughout life to a limited extent. However, it only happens in certain parts of the brain. And many of the newborn cells die shortly after they are created.
To help prevent or delay neurodegenaration, we want to increase neurogenesis and also to produce new mitochondria in our brain cells. Exercise increase both the creation of new brain cells and also spur growth of new mitochondria in existing cells.
In addition, oral coenzyme Q10 have been shown to increase brain mitochondrial concentration in mouse models. Coenzyme Q10 is an antioxidant and help support the mitochondria.
Interesting Facts about the brain
There have been evidence that in pre-industrial time, some people practice biphasic sleep where they sleep for a few hour right after sunset. Then wake up in the middle of night and is very alert. And then they go back to a second sleep before daybreak.
Some parts of the brain is more active during sleep than any other 24 hour period.
Although serotonin is a neurotransmitter, 90% of all the serotonin in your body is located in gut.
-  The Other Brain Cells: New Roles for Glia - ScientificAmerican.com
-  How to Classify Different Types of Neurons, or The Dendrology of the Neuron Forest - ScientificAmerican.com
-  Einstein's Brain Unlocks Some Mysteries Of The Mind - NPR.org
-  Book: Saving Your Brain by Jeff Victoroff
-  Coenzyme Q10 administration increases brain mitochondrial concentrations and exerts neuroprotective effects
-  How Exercise Can Strengthen the Brain - New York Times
-  Book: Smart Fats by Michael Schmidt