This lesson is called Damage and disease in the human brain, including fMRI and electrical stimulation, and is from the unit Coordination and control: the human nervous system.

Hi there, my name's Mrs. McCready and I'm here to guide you through today's lesson.

So thank you very much for joining me today.

In our lesson today, we're going to describe some of the difficulties in studying and treating damage in the nervous system and the brain and we're gonna have a look at some specific techniques used to help to understand what is going on.

Now, we're gonna come across a good number of keywords in our lesson today, and they're listed up here on the screen for you now.

You may wish to pause the video and make a note of them but I will introduce them to you as we come across them.

Now in our lesson today, we're going to first of all look at investigating brain function and damage and some of the problems associated with that before we zoom in on two specific techniques, fMRI scanning and electrical stimulation.

And then we'll finish off by looking at how we might treat the brain and the nervous system and some of the problems and treatments available there for that.

So, you ready to go? I certainly am.

Let's get started.

So we know that the brain is a hugely complicated organ and it's also incredibly fascinating because after all, it controls everything about our body and our personality.

But when we look at the brain, say perhaps removing one from a recently dead animal, we can't really tell very much about how it works just by its appearance.

So by looking at it, we can see that it has two halves to it, two hemispheres.

We can see that it is highly folded and you can see all of those folds within those red streaks on the diagram there.

And we can see that it's got a really good blood supply, so it needs a lot of oxygen, it needs a lot of nutrients.

But other than that, that's about all that we can tell.

And even if we zoom in using a microscope, we can't really tell much more detail about how the brain actually functions.

In other words, what parts of the brain are controlling what parts of our body just by looking at it.

So, this makes understanding how the brain works really, really difficult to do, but it's really important that we understand how the brain functions because if someone develops brain damage of some form, we need to be able to understand how the brain works in order to be able to predict the kind of damage that is likely to have been incurred by that damage.

So if a certain part of the brain gets damaged, say within a stroke, then we can, if we understand how the brain works, we can then predict what damage that patient is likely to have upon recovery.

But if we don't understand what the various different parts of the brain do in the first place, then we couldn't possibly make those predictions secondarily.

It's also really important to be able to understand how the brain works if we want to develop treatments for damage and disease that might be incurred to the brain.

So, diseases might include dementia and Parkinson's disease, epilepsy and depression, and maybe brain damages from injuries such as sustained through an accident, a car crash, for instance.

These are all instances where damage can be caused to the brain.

And not only do we want to know what damage has been inflicted, but we also want to treat it and improve the condition for the patient.

So understanding how the brain functions is really important to both understanding what part does what and how we might then go and improve that function should it be damaged.

However, there are lots of different problems associated with doing this kind of research.

Firstly, we're dealing with patients who are living and when we're dealing with any living organism, be that human, lab mouse, a plant, we have to do so ethically.

Now, doing so ethically means that we consider the impact of all of the actions that we are going to be taking on the patient.

So that means that the actions that we're taking, the consequences that those actions will have, are they right? Are they fair? Are they moral? Will they cause harm? And if they're going to cause harm, then we shouldn't do them.

So trying to be ethical in our approach means that we are trying to be considerate of the actions that we're taking and the consequences that those actions will have.

And we're trying to make sure that those consequences are right, they are fair, they are moral, and that they don't cause harm.

So if the actions that we are taking have damaging consequences, then they are not ethical and we need to be ethical in all of the approaches that we take when we're dealing with any living organism, be that human, lab rat, or plant, for instance.

Now with humans, ethical practises also involve seeking informed consent.

Now, informed consent means that the patient fully understands what they are agreeing to before they give their consent.

So we haven't just asked them to sign on a dotted line without explaining what they are agreeing to, and we aren't just carrying on without asking for their permission in the first place.

Now, there's a real difference here to be very clear about.

Getting someone to sign on a dotted line does not equal informed consent.

And in fact, informed consent does not require a signature.

It requires the patient to be of understanding of what is going to happen.

Now, they might not be able to sign on the dotted line, but if they understand what is going to happen to them, then they can give consent.

Conversely, you could ask somebody to sign on a dotted line and them not understand what on earth they're signing up to.

So, just because they've signed doesn't mean to say they are giving informed consent.

It's really important that informed consent is obtained before procedures and research is then carried out.

There are some other ethical issues and hurdles that have to be overcome when we're studying the brain.

So firstly, when we're trying to study the brain, we've got to get access to it and that involves removing part of the skull.

And removing part of the skull instantly exposes the brain to damage, potential damage.

It might not necessarily damage the brain but it highly increases the risk of brain damage being incurred.

So, accessing the brain via the skull is in itself really precarious and potentially very damaging.

Furthermore, we need to make sure that they have consented with understanding in order for us to carry out brain research.

And then alternatives to that might be involving lab animals, for instance, but damaging an animal's brain just to see the effects of that damage is in itself very difficult to justify, especially when there are other techniques available to be used.

So studying the brain, given that when we look at it it doesn't really tell us very much, is really, really challenging.

Now, some of our understanding has come from researching people who have sustained significant damage to their brains.

And this has often been through investigating the damage caused by warfare to soldiers or to people from significant injury such as through a car crash or from disease like cancer.

Historically, these techniques have provided us with a lot of information about how the brain works and was a great starting point.

However, the morality and the ethics sitting behind these research methods are questionable, and we wouldn't be able to use these techniques in our modern day society, and quite rightly so.

However, with developments in technology, there have been significant developments in the way that we can research the function of the brain, and we're gonna have a look at some of these techniques in a little bit.

These have created quite a significant improvement in how we understand what parts of the brain are controlling what parts of our body or personality.

So, let's quickly check our understanding on this term ethical practises.

What does that mean? Does it mean A, good and godly, B, moral and right, or C, no injury caused? I'll give you five seconds to think about it.

Okay, so ethical practises means moral and right.

Did you get that correct? Well done if you did.

What about this term informed consent? So what does that mean? Does it mean A, the patient can sign on the dotted line, B, the patient has been told about what is going to happen, or C, the patient understands what they are agreeing to? Again, I'll give you five seconds to think about it.

So, informed consent means that the patient understands what they are agreeing to, but remember it doesn't require a signature on the dotted line and it doesn't just involve them being told.

What about this then? Which of these statements indicate ethical issues involved in studying patients with brain damage? So, is it A, the patient may not benefit from the research? Patient B, the patient's brain function may be severely limited from the stroke.

C, the patient may not be able to consent to the research.

Or D, the brain is a dense mass of neurons and connective tissue.

But which of these are ethical issues? Again, I'll give you five seconds to think about it.

Okay, so from this list you should have chosen that A, the patient may not benefit from the research and C, the patient may not be able to consent to the research are both ethical issues.

Now whilst B and D are true, they aren't ethical issues, which is why we haven't indicated these as correct.

If you've got both of those correct, well done indeed.

So what I'd like you to do now is to consolidate our understanding about investigating brain function and damage by considering these two generalised techniques of causing deliberate damage to laboratory animal brains or using equipment to take a live brain scan of humans.

So what I'd like you to do is to describe the benefits and the problems with these two techniques that's deliberately damaging lab animals or using equipment to scan live human brains.

So I'd like you to describe the benefits and the problems of these techniques when we are trying to learn more about brain function.

So pause the video and come back to me when you're ready.

Okay, let's see what you've included then.

So I asked you to describe the benefits and problems of using lab animals and human live brain scans when we're trying to learn more about how the brain functions.

So for lab animals, you should have included that the benefits include that damage can be caused very precisely and that therefore can be used to identify specific areas of brain activity with their function.

However, the problems are that the ethics to do with this technique are very challenging because what we are doing is causing deliberate harm to the animal and that's very difficult to justify.

However, with the brain scans of humans, you should have identified that the benefits are that they are not harmful techniques, they are completely ethical and can be done with informed consent and without causing harm.

However, the problems are that interpreting the data that we get from these sorts of scans is really complex and it's also really difficult to get people to sign up to these studies.

And sometimes this is because patients aren't actually able to do that because of the type of brain damage that they have incurred.

And also when you're that poorly, you might not want to do anything other than focus on medical treatment and getting as well as you can do.

So have you included all of those aspects within your answer? Add anything in that you have missed and well done even if you've come up with only a few of these suggestions, that's excellent because trying to identify the ethics and the moralities around these techniques is really quite challenging.

So good job.

Well done.

Okay, let's have a look now at some techniques for investigating brain function including fMRI and electrical stimulation.

So let's have a look at fMRI first.

So fMRI stands for functional magnetic resonance imaging and this type of scanning allows us to see active areas in the brain whilst the patient is awake and doing tasks.

That's what the functional part means.

It means that the patient is able to be doing something whilst being scanned.

Now, an fMRI scanner uses very powerful electromagnets that can detect changes in blood flow to areas of the brain.

So, as the patient is doing an activity, the blood flow to various parts of the brain changes, and as the activity in the brain increases, so does the blood flow because of course that part of the brain requires more oxygen and more nutrients in order to carry out its function.

So as brain function increases, blood flow increases and that can be detected by the fMRI scanner.

Now FMI scanners can take snapshot pictures throughout the body or in this case throughout the brain and then sort of stack them on top of each other to create a 3D map, which can then be zoomed in and looked around.

And by doing so, areas of differing activity can be identified specifically when particular types of actions are being performed by the patient.

So, perhaps they're wiggling their toes, a certain part of the brain lights up for that.

Whereas if they're reading something or listening to some music, that sort of thing, then other parts of the brain will be highlighted instead.

And you can see on the map that is created, the areas where very high activity is taking place are highlighted in red.

But areas where there is no activity at all are in very dark blue to black and all the colours in between to show different levels of activity.

So we can see that by undertaking a task and observing the blood flow through the brain and how that changes we can identify or at least start to make links between certain parts of the brain and the function that those parts are performing.

That also means then that if a patient isn't able to do something or if they're thinking that they're doing something but is not actually happening, we can see that there's parts of the brain that they're missing.

And so, fMRI scans are able to identify damage to the brain as much as active areas of the brain so they can identify areas damaged by the brain through stroke or dementia or cancer for instance.

So as I say, areas of the brain that are most active at the time of the task show up as active areas on the brain scan, and you can see them in the images here.

So this means that researchers can link parts of the brain to specific functions such as to muscle groups.

Now the problem with fMRI scanning is that it uses electromagnets.

So hopefully you can see where I'm going with this, that if we're putting a patient inside an electromagnet, if they've got any metallic implants such as a pacemaker or an artificial heart valve or a replacement joint, then they might not be able to go into the scanner.

And that's because the electromagnet may well move the metallic implant around and either damage the body or damage the implant, neither of which would be particularly good for the patient themselves.

So, patients with metallic implants have to be really careful and may not be able to be scanned in this way.

So, let's quickly check our understanding.

Patients with piercings cannot use an fMRI scanner.

Is that true or false? I'll give you five seconds to think about it.

Okay, so you should have said that patients with piercings can use an fMRI scanner.

In other words, this statement is false.

Why though? Can you think of an explanation? So you should have said that although the piercings will be metal, they can be removed and therefore as long as they have been removed, the magnets in the fMRI scanner won't affect the patient.

Well done if you've got both of those correct.

Right, let's move on to see what electrical stimulation is about.

So electrical stimulation is actually a set of techniques that can be used to directly stimulate the brain.

And you can see there in the picture a version of electrical stimulation called deep brain stimulation, involves the insertion of electrodes deep into the brain so that they can be triggered and that part of the brain can be activated specifically.

Now, electrical stimulation can be used to identify links between the brain and the parts of the body it controls similarly to fMRI I suppose.

And essentially what happens with this form of electrical stimulation is that the part the brain is stimulated by the researcher and the patient then describes what they experience.

So they might see lights, they might hear a sound, or they might make an involuntary movement.

And this enables scientists to build up a much better understanding of exactly which parts of the brain have which functions and what happens to those parts of the brain if they become damaged.

So let's quickly check our understanding on this.

So electrical simulation can identify links between areas of the brain and function.

True or false? Okay, so you should have said that that is true, but can you explain why? Okay, so you should have said that electrical stimulation can identify links between areas of the brain and the function because patients describe the sensations that they experience when certain parts of their brain are stimulated and this can therefore suggest links between the area of the brain and its function.

Well done if you've got both of those correct.

So what I'd like you to do now is to consolidate your understanding about fMRI and electrical stimulation by creating a patient information leaflet about these procedures.

So for each procedure, I would like you to include a description of the procedure.

I would like you to say how they stimulate or create an image of the brain.

I would like you to describe what they might be able to treat or observe.

And any restrictions or cautions that might be appropriate.

So pause the video and come back to me when you're ready.

Okay, let's take a look at what you might have written then.

So for fMRI, you might have included that fMRI stands for functional magnetic resonance imaging and this is where the patient lies on a bed and then enters the fMRI scanner.

And the scanner uses electromagnets to detect changes in blood flow to areas of the brain.

This enables researchers or the medical team to identify changes in the structure of the brain such as those caused by stroke or dementia or cancer.

You might also have said that as the brain activity changes, so does the blood flow and the active areas of the brain can then be identified.

These are the functional areas of the brain.

Now, patients who have metal implants, particularly those made of iron and steel, need to be really careful with scanners.

So any patients who have a heart valve, a pacemaker, or replacement joints for instance, may not be able to use the scanner because of the electromagnets that it uses.

And patients who do have piercings need to remove those piercings before they use the scanner.

So check your work over.

Make sure you've got all of those salient points.

Well done.

Now let's have a look at electrical stimulation.

So for this, you might have included that electrical brain stimulation, EBS, this is a set of techniques that directly stimulate the brain in different ways and essentially, the patient has their brain stimulated and then they describe the experiences that they have had when those specific areas of the brain are stimulated.

And what this allows is for links to be made between the brain and the parts of the body that it controls.

So, just check over your work, make sure you've got all of those salient points, and well done again.

Now in the last section of the lesson, we're gonna have a look at how we might treat the brain and the nervous system.

So when we're dealing with brain and the nervous system, we're ultimately talking about neurons.

Now neurons are extremely complex cells and you can see just a glimmer of that from the image there on the screen.

They have many different parts to them, each of which is highly specialised.

They are very long cells often, and they interconnect with many, many other cells in very specific ways.

So they are very complex and that makes them incredibly difficult to treat if they become damaged through disease or injury.

Added to that is the fact that neurons cannot undergo mitosis.

And mitosis is a form of cell division, which creates identical copies of the original cell.

Now, neurons because they are so complex in their structure, that is what is prohibiting them, preventing them from completing mitosis.

So neurons cannot make new copies of themselves through this process of mitosis.

And this means that they cannot fix themselves, in addition to the fact that it's incredibly difficult for us to fix them too.

Put the two together and it makes treating any neuron-related damage incredibly difficult to complete.

Added to that, the problem of the very important role of coordination and response that the nervous system has within our body, if we start tinkering around with different parts of the brain or the neurons in the nervous system, we have to do so extremely carefully because one false move, one minor mistake could lead to irreversible loss of function for a particular part of the body.

And that would be disastrous because not only would it have caused more damage than we had before, it's also incredibly difficult to then undo that damage that has been caused because neurons can't fix themselves because they cannot undertake mitosis.

And because they are so complex, it's very difficult for us to fix them for them too.

Now, when we're talking about certain types of brain damage or disease, there are certain techniques that we can use to help manage those conditions.

So for instance, epilepsy, Parkinson's, and depression are all diseases that can be treated or at least managed through certain types of brain stimulation for instance.

Now brain stimulation is about triggering certain parts of the brain into being activated.

And for certain conditions and for certain patients, this might be a useful technique to use.

However, what is on the cutting edge of science is whether stem cells can be used to grow replacement neurons because that ultimately might actually be the easier way of dealing with problems to do with the nervous system if we can simply take a damaged neuron or neurons out and replace it with some new ones.

So what's a stem cell? A stem cell is an undifferentiated cell.

That means it has no particular function at present.

It has yet to differentiate into its specific role.

And stem cells come from a number of different places, including embryos and in adults in bone marrow.

And stem cells can then differentiate into a specialised cell, one of many, and a neuron is one of those.

So we could possibly take a stem cell, an undifferentiated cell and differentiate it into a neuron.

Now, that process of differentiating a stem cell into a specific cell can happen in a lab.

And by happening in the lab it can be used to create tissue.

Now, this is a potential technique for replacing large sections of damaged tissue, such as large sections of pancreas in patients with type I diabetes.

Alternatively, stem cells could be injected into the damaged area and then triggered to differentiate and grow in situ, that means in the location required.

Now, this would be more suitable for replacing neurons because they're not large organs like the pancreas, but instead a few very fine strands bundled together, such as in the spine.

And if someone has, for instance, damaged their spine and become paralysed from say the waist down, if stem cells can be inserted into where the damaged part of the spine is and then triggered to differentiate into neurons, it's possible that those stem cells can turn into neurons and essentially bridge the gap between the top half of the body, which is working and the paralysed lower half, which has been severed from the top half, bridge that gap and restore function.

And in fact, that's actually been done in the UK and whilst it's still a work in progress, it is leading to some remarkable improvements in patients' quality of life where people who have been paralysed and are unable to walk are suddenly able to start to learn to walk again.

It's really quite remarkable.

So we've got these two uses for stem cells.

One either growing them in a lab and then inserting whole pieces of tissue into the patient or inserting the stem cells directly into the patient and then triggering them to differentiate into the specific type of cell that is required such as a neuron.

So, let's check our understanding.

What is a stem cell? Is it A, a specialised cell, B, a differentiated cell, or C, an undifferentiated cell? I'll give you five seconds to think about it.

So a stem cell is an undifferentiated cell.

Well done if you got that right.

What about this time? Damage to neurons is difficult to repair because the cell cannot undergo meiosis.

Is this true or false? I'll give you five seconds to think about it.

Okay, you should have said that that is false, but why? Okay, so you should have said that that is false because neurons are very complex cells and cannot undergo mitosis to create new copies of themselves, not meiosis.

Be careful of those two forms of cell replication because they are different and well done if you've got both of those right.

So what I'd like you to do now to conclude our lesson is to firstly define the term stem cell and then describe how, theoretically, patients who have suffered extensive injury to the nerves and the spinal cord, leaving them paralysed, may be able to walk again with stem cell treatment.

So, pause the video and come back to me when you're ready.

Okay, let's see how you got on.

So firstly, I asked you to define the term stem cell.

So you should have said that a stem cell is an undifferentiated cell which can differentiate into any specialised cell.

Then I asked you to describe how people who have been paralysed may be able to use stem cell treatment to learn to walk again.

And you should have said that stem cells are able to differentiate into neurons and if they are injected into the body where the new neurons are required, such as in the spinal cord where the damage is, then they may be able to differentiate into neurons and repair the damage.

And as I said, this is actually happening.

This research has been proven in its infancy to work.

So check over your work and well done if you got those right.

Okay, we've reached the end of our lesson today.

We've covered an awful lot today, so well done.

So in our lesson today, we have seen that it is difficult to study the brain and to learn how it functions and how it's affected by disease and injury just because of its incredible complexity.

And that also if we want to study the brain, we have to do that safely, we have to do it ethically, and we have to have informed consent from the patient.

And that adds to the complexity of studying what is already an incredibly complex organ.

Now, there are a variety of techniques available for studying live brain function, including fMRI and electrical stimulation that we've looked at today.

However, treating brain damage is equally difficult because of the complex nature of neurons and because the fact that they cannot enter mitosis once they have finished forming.

So this makes it much more difficult for us to treat neuron-based injuries and damage.

However, stem cells are being used to treat damage and disease in the nervous system.

It's complex, but it's proven to be possible.

And so, it's still work in progress.

So I hope you found that an interesting lesson today.

It's certainly been quite a complex one so well done for getting through it all and I hope to see you again soon.

Bye.