So I looked at fear last week and I will examine memory and trauma next. Before that, it will be useful to review how the brain works in a nutshell. The basics aren’t difficult. Here’s a little Brain 101 with a twist: neurons and synapses represented in text symbol pictures.
The brain is a network of cells called neurons that channel information in the form of electric charges and chemicals. A neuron has a main part – the cell body. At one end of the nucleus is a group of fibrous tentacles (called the dendrite) that branch out and bring information into the neuron. At the other end sits a couple of long fibers (called the axon) that blast information out. Simplified in text picture symbols, a neuron would look a little like this:
- The > is the “information in” end (dendrite),
- the O is the main body of the neuron (cell body), and
- the – is the “information out” end (axon).
Synapses connect neurons. A synapse is the space between the end of one neuron and the beginning of another. Cell bits called neurotransmitters (and other cell bits) live in the “information out” side of one neuron, and across the gap, cell bits called receptors live in the “information in” side of the next neuron.
In picture symbols, the synapse is the space between these two neurons:
Electric charges racing through the axon on the left ( – ) shoot neurotransmitters or other chemicals across the synapse, or space between ( ), and into the open arms of receptors sitting in the dendrite on the left ( > ).
The brain is a beautifully intricate network of these neurons and synapses. Like the below chain of symbols, but many different directions and a far more complicated fashion:
>O– >O– >O– >O– >O– >O– >O– >O– >O– >O– >O– >O– >O– >O– >O– >O–
These electric charges and shooting chemicals are everything we are.
Everything we think, remember, feel and do all come from this relay.
What we sense and perceive stimulates different parts of our brain, which send signals to the rest of our brain and different parts of our body.
The first five minutes of this fun drawing-explanation tell the real story behind the concepts above (I got over the hiccups in narration – the message is still good. It’s a little technical after a certain point…):
And an example of what real neuron in a human brain looks like is this:
(Here’s the link to the source photo.)
But wait… There’s more!
Researchers have recently found a new type of neuron in mouse brains. This type of neuron fast-tracks signals directly from axon to dendrite without having to go through the cell body. Axons attach directly to dendrites. Kind of like this:
Maybe we have the same in humans. I’d like to know. There is a bit of a question mark, though. The researchers have yet to find out what kinds of brain signals are so important that they need fast-tracking. My neurons and synapses are bursting to find out more.
Finally, it just so happens that the new types of neurons are located in the hippocampus – the part of the brain that, among other things, processes memories (or doesn’t). This is what I’ll point my axons to next. (That is, in between the NaNoWriMo frenzy…)