Let me show you something amazing...
So, as we all know, this is a self-help site. I’m here to help you get the life you want. Now one of the things you RARELY find is someone in the self-help field who talks about how the brain works. They’ll talk about a lot of other little theories and tricks you can use, but they don’t have a basis in the nuts and bolts of your brain. So, few people who are striving to make a change end up understanding what’s going on under their skull and have to rely on pseudoscience and pop psychology and some of it is completely wrong.
I’m going to rectify that. There are some things that you can learn about your brain that will help you understand what’s really going on and filter out what does and does not work out there. In this article, I’m going to teach you the details of how neurons, the basic building blocks of the mind, actually work. And once you understand the basic principles they work under, you’ll understand some of the basic principles that underlie the mind.
Intrigued yet? Good. Let’s begin at the very beginning…
Atoms and Molecules
Didn’t think we were going to start THIS small, eh? Biochemistry isn’t too hard when you understand the core basics. And this is about as “core” as you can get.
Now, there’s some terminology we need to discus. An atom is the smallest particle of an element, such as oxygen, hydrogen, gold, chlorine, iron, etc., and different atoms bind in different ways to create a variety of molecules, which are more complex. For instance, sugar is a molecule made up of 12 carbon atoms, 22 hydrogen atoms, and 11 oxygen atoms. Because of the different ways these atoms bind to each other, you end up with not just a glob of atoms, but an actually shape to the molecule as well. The fact that molecules have unique shapes is important, and we’ll come back to it in a bit.
Let talk about the smaller end for a second. Atoms are made up of neutrons, electrons, and protons. Protons and neutrons make up the core of the atom. Protons have a positive electrical charge, while neutrons are neutral. Electrons, which have a negative charge, orbit around the protons and neutrons. When there are as many electrons as protons, the atom has a neutral charge. But, because electrons are free-floating around the core of the atom, they can get pulled off and migrate to other atoms. This ability of the electrons to move is what creates the phenomenon of electricity. Neat, eh?
Anyway… When an electron gets pulled off an atom, that atom ends up with a positive charge. When an electron is added, the result is a negative charge. There are atoms that either easily lose a single electron, or strongly attract other electrons. These, they’ve lost or gained an electron, are called ions. The most notable two are sodium and chlorine. One sodium and one chlorine create one molecule of salt. When they’re dissolved in water, however, the chlorine hangs onto one of the sodium’s electrons, giving the chlorine a negative charge and the sodium a positive charge. If the water dissolves, the ions are attracted to each other, since opposite charges are attracted to each other, and form salt again.
Now, keep this in mind: a positive and a negative together create a neutral, but when you separate them, then you get a positive or negative charge and opposite charges are naturally attracted to each other in order to get back to that neutral state. This will come into play later.
Proteins: The Movers and Shakers of Your Brain
Now, proteins are complex structures. The basic building block of a protein is an amino acid. Amino acids are short strings made up of carbon, hydrogen, oxygen, nitrogen, and sulfur and they connect with each other end-to-end to form long strings that form the proteins. The interesting thing, though, is that there are 20 different amino acids, each of which has a different group of atoms attached to the middle of the amino acid called the R-group or side chain. These side chains each have different properties, and certain ones are attracted to each other. It’s like having a necklace made from a selection of 20 different beads, and some of the beads are magnetic. The result is that the necklace would bunch up into a 3-dimensional shape instead of staying just a string. In this way, proteins form complex structures.
This effect can be changed, however, by altering the environment the protein is in. If the temperature is raised or lowered or the pH changes (that is, if the environment the protein is in becomes more acidic or basic) or the electrical charge in the environment changes, then bonds across amino acids that form the structure can be altered. The result is that the shape of the protein changes.
It’s kind of like sticking a plastic container in the microwave. After it gets hot enough, its shape starts to warp. Proteins are similar, but it’s more than just getting them hot that can change their shape.
Now here’s the crazy part where all of what I just wrote about proteins should start to make sense. Because the environment can cause proteins to change shape, they can serve mechanical functions. They become microscopic simple machines in your cells. Neat, huh?
Ions and Membranes and Pumps, oh my!
Now, where this really comes into play are in the cell membranes of the neurons themselves. Many people know that neurons create electrical impulses when they fire. But how do they do it? The area inside and around the cell is filled with ions. Normally, like dye dissolving into water, they spread out and fill all the available space equally. Because there’s an equal concentration of positive and negative ions, the charge all together is neutral. But, if you could separate them out by polarity, then you’d end up with one area with a positive charge and one with a negative and because positives and negatives attract, instead of moving randomly they’d be more likely to move toward each other if you let them. This creates a potential for action (otherwise known as the action potential).
Now, there are 3 ions that are used in the process of a nerve firing. Chlorine and sodium have already been mentioned, but potassium is another one. Because each of these ions is a different physical size, some can get through the membrane of a cell easier than others. Potassium has the easiest time getting through a cell membrane, while sodium is the slowest. In order to have the potential for a nerve to be able to fire, the greatest concentration of potassium ions needs to be inside the cell, while most of the sodium ions need to stay outside. This is not the natural state that they want to be in, so the cell has to exert energy to keep the potassium in and the sodium out.
This is where proteins come in. Nestled into the membrane of the cell are protein structures called channels. There are different kinds, but essentially they’re like gates that open up to let ions pass in and out more easily. Some, though, are pumps, and there is a particular one that is shaped to fit a potassium on the outside and a sodium on the inside. When these two ions lodge themselves in the protein channel and then a molecule, called ATP (a molecule produced by the mitochondrion of the cells to power mechanisms like these) also attaches to the protein on the inside of the cell, and with everything in place the protein pump changes its shape to push the potassium ion back inside and the sodium ion back out. This process breaks down the ATP molecule.
Essentially, the ATP is created by the mitochondrion (the power plants of a cell that mix sugar and oxygen). You can think of it as one unit of fuel or energy. So the process of keeping the sodium and potassium in the right places takes a unit of energy every time it’s done. So your body has to exert one unit of energy for every ion that slips out of place. Because ions are constantly moving across the membrane, it requires energy to keep your neurons going, even at rest! On the upside, the amount of energy required to work an ion pump is extremely minute, but with billions of cells all working to maintain a balance you can begin to see why the brain is the most energy-consuming organ in the entire body.
All That Energy Has To Go Somewhere…
Now, the resting state is actually a state of readiness, and it all it takes is a shift in the concentration of ions between the inside and outside of the cell membrane to set it off. Once it reaches a certain concentration, the neuron fires. What happens is this change in concentration changes the charge of the cell in that area, and that change in charge changes the shape of protein channels that begin to open to let sodium ions flood inward. This sets off a chain reaction.
The increase of sodium ions causes the cell to become positively charged, and that change in charge causes OTHER protein channels to open and let the potassium ions out. Now, this chain reaction starts on one end of the cell, but the change spreads the length of the cell as the change in charge affects nearby areas and they too open their sodium and potassium channels. This is the electrochemical process that transmits signals along neurons.
It’s kind of like a stadium of people doing “the wave” at sports games. When a couple people decide to stand up, the people next to them follow suit, while the people next to those do so as well. It continues in a chain reaction until it reaches the other side of the stadium.
What you need to realize here is that the firing itself takes no energy, but then the pumps have to work overtime to restore the nerve to readiness, and when the nerve is ready it’s easier to fire than to not fire. This creates a system where our nerves are firing frequently. If you’ve ever felt scatterbrained, or noticed that your thoughts were wandering all over the place, this is part of the mechanism involved. It’s our nature!
Nerve Talk
One nerve alone doesn’t do much. It takes many working together to form a thought. Here’s how. There are basically four parts of the nerve. There are dendrites on the one end presynaptic terminals on the other, and the bell body and axon in between. Let’s make sense of that gibberish.
The cell body is where all the organs of the cell reside to keep it alive. That’s pretty simple. The axon is the long tail that reaches out toward other neurons. At the end of the axon, it branches out into tendrils that connect with other neurons at a microscopic gap called a synapse. Presynaptic terminal is a fancy word for the end of the axon that terminates at a synapse. On the cell body side are dendrites, which are mini tails that reach out to connect with the presynaptic terminals at the end of the axons from other neurons.
The long and the short of it is simple: Any given neuron has from one up to thousands of other neurons sending a signal to it, while it sends signals to up to thousands of other cells. Now, if any one neuron could cause another to fire, we’d all suffer from epileptic fits all the time. Regulating mental and physiological functions would be completely impossible. Instead, a certain amount of impulses have to be received in order to cause a neuron to fire. Once it reaches that point, called the threshold, THEN the neuron fires.
Now, in that gap between neurons, chemicals are released called neurotransmitters. There’s a big deal made out of neurotransmitters such as serotonin and dopamine. They really aren’t at all important in this discussion. You see, certain neural circuits use certain neurotransmitters, and so the balance between neurotransmitters is really a balance between the neural circuits that use them.
We’ll get into parts of the brain another time, however.
In any case, neurotransmitters transmit a signal chemically from one neuron to another instead of electrically because that regulates the amount of signal that the receiving neuron gets. When a receiving neuron gets a neurotransmitter, those neurotransmitters may trigger the ion channels in the cell to open, changing the charge of the cell, and triggering it to fire when enough neurotransmitters open enough ion channels so that the electrical threshold is reached to set off the chain reaction of a nerve firing.
This threshold can be reached either by having several neurons sending impulses to the receiving one all at once, or through repeated firings from only a few until it’s pushed over the edge. On the one hand, think memory. The more details as well as emotional associations you have linked to a memory, the stronger it is. On the other, think sex. It takes repeated stimulation to push someone over the edge to orgasm.
Simple, eh? There’s more. Here’s another vitally important, but little-known fact. Not only are there neurotransmitters that stimulate the next nerve to fire, but there are also neuotransmitters that attempt to prevent the nerve from firing.
Nerves Police Themselves
Now it’s time to think of nerves working together to accomplish something. One neuron may fire, urging a nerve which happens to be controlling a muscle into action. The other neuron might fire and try to keep the nerve connected to the muscle from firing. Their respective influence may just add up to nothing happening. This happens in your brain all the time.
Without getting into a detailed explanation of the different parts of the brain and how scientists think so far that they interact, lets just say that while there are some parts of the brain that are wired to initiate movement, such as our survival instincts like the fight or flight response, other parts of the brain are there to suppress other parts to prevent a mindless reaction. This is the delicate and deliberate balance that runs our brains.
Now let’s apply this to our behaviors. I’ll use the example of an addiction. Addictions are strong impulses to behave a certain way. Smoking, for instance. You can, however, resist the urge. People call this willpower. Willpower does not last forever for a simple reason, however. Willpower is a function of another group of neurons acting to suppress the movement. Addictions are often habits that have been reinforced through repetition. This means that the neural connections that drive them have been reinforced themselves.
On the other hand, neural connections that we don’t use very often are pared away. In an addiction, the impulse to indulge is often stronger than the knowledge that the habit is bad and the desire to stop. The neurons that are responsible for stopping the impulse toward addiction have to work extra hard to suppress the urge if you exert willpower to restrain yourself. Because these neurons have to fire more often they use up much more energy. Basically, one part of your brain has to go into overdrive to prevent the other part that wants to pick up a cigarette from doing so. The fact of the matter is, sooner or later you’ll run out of energy, whether from fatigue or the effect of other stressors and those neurons will be exhausted.
This is where people fall off the wagon. They’ve spent so much time fighting against themselves that they’re not only emotionally tired, but literally physically tired as well.
Now, I’m not saying that you should never use willpower. It’s a good thing to be able to stop yourself from mindlessly reacting every now and then. But don’t rely on it in the long run, and, more importantly, you do have the same natural human limitations as everyone else. Whether you’re fighting procrastination or you’re fighting an addiction, if you falter it’s not necesarilly your fault. It’s just an indication that instead of kicking yourself you should rest up so you can have another go at it.
This is a very important concept to understand, and it’s really the reason why I wrote this extra-long and detailed article. Your brain is a physical entity that’s governed by physical rules. If you learn how they work, you can change how you think in a way that is natural instead of forced. This is also why changing the well-rooted drives of the problem is more effective than trying to kick something else into overdrive to overcompensate and suppress that problem.
Has Your Head Exploded?
I’ve presented a lot of information to you. I hope that it all makes sense, even if you have to read it a couple times to digest it. If not, though, feel free to get in contact with me and I’ll be happy to answer your questions and clarify anything that didn’t make sense. If you have other questions about the brain, feel free to ask those too. I might just write an article on it. After all, there is lots to write about.
In the meantime, here are a few good links explaining what I’ve presented to you in more detail.
How a protein’s structure works
The math behind the action potential
A fantastic site with animations showing how a nerve works
