The C.E.O of the Body - Cerebral Cortex: A Journey into the Brain's Command Center.

4 months ago (Edited)

As a continuation of yesterday's blog post, we now turn to the cerebral cortex, the CEO, the part of the nervous system that makes us intelligent beings. Like we saw in the cats experiment, its presence or absence may not be utterly necessary, even though we noticed the animals are helpless without it.

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But when it comes to we humans, the absence of a ceberal cortex is highly catastrophic. Reason is, without it, there cannot be any form of planning, complex sequence of motor movements, perception in organized form, or speech. What you'd have after taking this brain region out will have no resemblance of anything that we call or know to be human .

Now the first discoveries made in the study of cortical function was the existence of something called projection areas. These areas serve as receiving stations for sensory information or as dispatching centers for motor commands.

Sensory projection areas are basically parts of the cortex where messages coming from our senses, often through relay stations, are initially received, whiles motor projection areas are those from which instructions that finally go to the muscles are issued.

In simple terms, "projection" in this context means that areas in the body, related to movement and senses, are mapped onto specific regions of the cortex. This creates a basic match between where something is in the body and where it's managed in the cortex.

This also shows us that everything in our body is linked and controlled by some part of the brain.

Amazing Right?

Time for the interesting part:

Discovery of the cortical motor areas happened when several physiologists opened the skull of a lightly anesthetized dog and then applied mild electric currents to various part of its cerebral cortex. They located a region in the frontal lobe that controls movement.

By stimulating a specific point, it caused the forelimb to move, and stimulating another point induced motion in the trunk, and so forth. Also, by exciting the left hemisphere, it led to movements on the right side of the body, and stimulating the right hemisphere caused movements on the left. Now this makes perfect sense in anatomy because many important pathways from the brain switch to the other side right as they exit the hindbrain.

Other similar studies were conducted on human subjects by the Canadian neurosurgeon Wilder Penfield . This stimulation was administered in the course of a brain operation. Since these kinds of operations are usually administered under local(you are conscious) rather than general(unconscious and unaware) anesthesia, patients are able to report their experiences.

He discovered that electrical stimulation applied to the open brain produced no pain.

🤯

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Yep, this means your Brian has no pain receptor. It also means if something hits you in the brain you won't feel it.

While pain receptors are located throughout the body and send their messages upward to the brain , the receiver and interpretator itself has none.

The study's findings revealed that the motor area in the human brain is in a part of the frontal lobe similar to that of dogs. When stimulated, it caused parts of the body to move. This was very surprising to patients who felt no conscious intention or sense of doing the action themselves but did them anyways.

Through careful exploration, it was found that every part of the motor cortex corresponds to a specific body area. When a specific cortical area was stimulated, the related part of the body moved, and each hemisphere controlled the opposite side of the body.

The results are sometimes shown visually using a "motor homunculus," which depicts how the body is represented in the motor projection area.

Let's take a look at this video to get a graphical understanding:

https://youtube.com/shorts/ln6prSJbj6M?si=YAIpdXjkrVEnxhV7

When you look at the motor homunculus in the video above, you can see that not all parts of the body get the same amount of space in the cortex. More mobile and finely controlled body parts, like fingers and the tongue, get more cortical space compared to less precise and more general movements, such as the shoulder.

This allocation is obviously based on function, considering the extent and complexity of use.

Fascinated?

What's the point?

As we understand how the cerebral cortex works, it would help in treating neurological disorders better and develop more effective forms of therapies. For people recovering from brain injuries, this is highly crucial for designing effective rehabilitation programs.

Also, ongoing neuroscience research would greatly benefit from this knowledge, and it would potentially lead to more discoveries that could improve our cognitive abilities or address brain-related conditions.

The Bus Stops Here!

I hope you had a great time reading. I would love to hear your opinions on this matter or suggestions on how to improve these blogs. I genuinely enjoy learning and sharing information, and I want to ensure you enjoy reading. Until tomorrow, stay safe and have a great day!