What is an unhappy brain like?

Neuroscience as we know it today is a science that is quite young

Very recent To understand how the brain works, what the neurons consist of, its anatomy

and their function Well, it doesn't take you on a journey through the history of how neuroscience came into being Notice that up to the year 1905 we thought that the brain was a mass continues As a kind of fluid Where then the information so to speak Circulated Through that tissue that was the nervous tissue That's the idea that they had Up to 1905 But at that time arose one of the most important characters for neuroscience which is the Spaniard

Don Santiago Ramón y Cajal Ramón y Cajal thought and had the hypothesis that our brain was formed by some individual components Which we call neurons But nevertheless the theory at that time stated that there were no those Bodies that were independent but formed a whole network Continues through which the information coming from the senses was processed

That was the debate that was being carried out at that time at the international level

There were these two figures One was Don Santiago Ramon y Cajal and the other one was Camilo Golgi

Santiago Ramón y Cajal was trying to demonstrate that neurons were independent and therefore that they were separate That they were not a mass that was united Golgi in Italy defended the opposite hypothesis there are no neurons

that are separate but that form a continuous network

So Camillo Golgi designed a technique that is the tension that we know today as the Golgi tension

Which was based on the following idea If we put on the brain on a sheet of paper that we cut very thinly of the brain if we put there a liquid That liquid if it sticks to the Membranes of the structures if neurons really are individual beings Then we would see, so to speak, as independent balls and a small space between them

This would give the reason to Ramón y Cajal's hypothesis

If on the contrary our brain were a smooth tissue and there are no independent neurons But they form a network It was the reticular theory as the tissue, the staining technique It would be deposited all over the tissue and so we would see like a kind of a sheet

Constantly painted smooth with no gaps in between Thanks to the staining technique developed by Camillo Golgi Santiago Ramón y Cajal at the University of Valencia in the Faculty of Medicine He was able to demonstrate that the neurons were indeed independent bodies and that there was a very small Distance between them is a distance As small as 20 nm something absolutely minuscule but essential So that the electricity can propagate through the brain At that small distance that separates the two neuronal bodies They are called synopsis Thanks to the Golgi staining technique, but thanks to the hypothesis defended by Ramón y Cajal Today we still consider that the brain is formed by neurons that have a neuronal body

What we call Soma We can imagine it as something spherical although it has many shapes and morphology

Neuronal is very very varied and very complex

In our brain it is associated The morphological diversity of the neurons is associated to the complexity of the information it can process That soma sometimes that's pyramidal and sometimes that's spherical, sometimes that's oval there are sometimes it's elongated But that is the neural body Of the soma From the neurons of its neuronal body where the nucleus with all its genetic load resides which is surrounded by a membrane, of that neuronal soma Two branches arise One are the ramifications which are the dendrites The dendrites are the branches through which the neuron receives the information

From the other neurons When we talk about information we are referring to physical information Electric fields the electric discharges it receives from the other neuron But we are also referring to biochemical information

The neurotransmitters that come from other neurons Those packets those hormones packets of information biochemistry that are passed between the neurons there is that first branch which are the dendrites and there is another branch which is the one that comes out which are the axons The branch also sometimes called the neuronal tail

It's the information is the branch by which the neurons transmit Information to the other neurons The neurons, as Ramón y Cajal already said, as a matter of fact Alone they would not be of much use Although it is a cell that is very complex What it does Especially diverse And useful and functional to our brain It's that neurons can receive information and give Information The neurons therefore form in the brain a very large and very complex Circuit of structures that although they are independent the important thing is the communication between them

The important thing is the information What they give and what they receive from each other These won the Nobel Prize jointly to Ramón y Cajal and Golgi

Both for their contribution to the study of neuronal architecture

the architecture of our Brain It must be taken into account That within what are the names that we have in neuroanatomy many of them are reminiscent of the language that we use in botany This is because Ramón y Cajal was absolutely passionate about botany

An expert in botany in many things, a true genius

So he gave names not like the Neural spines branching, dendrites, neuronal forests, leaves Neuronals all these names that the anatomy describes to us Of the neurons because they come from their inspiration in botany

and it is absolutely recommended that so let's look at the graphs, the charts, the plates

What did Ramón y Cajal and his assistants paint Everything he saw at that time he painted under the microscope And they are authentic works of art that give us an idea of the complexity that has the Brain of the complexity that a neuron has Why it is fixed We have that neuronal body that soma that is the body What a neuron has and we said that it has these ramifications what are dendrites and what are axons so we've represented it in this way which is a little bit like this Reduced and simplistic But we can get an idea that in the brain those neuronal bodies have thousands of dendrites by which they connect to thousands of neurons Many times the connection between two neurons It is done in ways Various That is to say There are many branches connecting two neurons That which allows us then to imagine that a neuron has processed a certain information And it is able to transmit it to display Spreading all its information among a forest Complete neural We have the capacity To transmit the information to many neurons Simultaneously But it also has the capacity the neurons of transmit the same information In different ways To the same neuron I what this does is it makes the information processing very complex

Why when a neuron We imagine you want to transmit Some information can do it With a neuron speaking in a language With another one talking to it in another language or even With the same neuron speaking different neuronal languages at the same time what the neuron does is that we imagine that neuronal body that we call soma Which is surrounded by a membrane which is very important And so to speak we get a vague idea that the neuron is being charged Of electricity Gradually charging is charging is charging is charging And when it reaches a certain threshold Dependent on the Characteristics Morphological characteristics of these cells What the neuron does is that It fires an electric charge i

e

emits an electrical impulse What we call in technical language What produces a neuronal firing An electrical impulse that can be up to 100 times Higher than the electric charge it normally has That electrical impulse emitted by a neuron propagates Through its axon like an electric shock that reaches it To the neurons to which that neuron Is connected When a neuron emitted a Electrical discharge When a neuron is released from that neuron the neurotransmitters When this neuronal discharge is produced Some floodgates are opened In the neurons and it is released A neurotransmitter a little package Of information Neurons at which is connected to the neuron that just fired open Its floodgates all this through that little hole What is the synapse The gap that was so important To be able to say that the neurons were independent bodies and not a smooth tissue The neuron fires Opens its floodgates a neurotransmitter comes out those packets of information come out very many neurotransmitters and the receptive neuron opens certain gates and receives That neurotransmitter the neurotransmitters They have also been called the Packages of information biochemical bases Of thought When a neuron has received a neurotransmitter from the other According to Nature of that neurotransmitter For the neuron acts in one way or another There are neurotransmitters Which are excitatory That is to say When a neuron receives a packet of information from the neuron that has just produced a firing That neuron increases Its electric charge But there is also neurotransmitters What are inhibitory What is meant by When the neuron has just emitted an electric shot Release Those neurotransmitters that it receives The receptor neuron The inhibitory neurotransmitter makes the receptor neuron slows down Slow down Your electricity and therefore delay the time of its electrical trip inhibition is almost or more important than excitation in the brain Why because there must be processes that regulate the firing rate Of the neurons When a neuron fires it tries to propagate Its, its electric field therefore in space but not all of them Neurons not all areas of the brain have to respond to that Electrical discharge The extreme case that We have in Our uncontrolled propagation brain Of the electric discharges It is for example the case of epilepsy In that case the neurons fire, there is a deficit of inhibition and the electric charge propagates Through the brain With the consequent Deficits of cognition and processing we have It is important for some neurons to fire but also It is important that others do not fire inhibition It is one of the most important processes What we have in the brain But the important thing is that our neurons like yeah As individual entities are important But that concept of individuality because in neuroscience it has remained a little bit more in the background Because the important thing, as Ramon himself said and Cajal advanced the important thing of the neurons is that they connect With each other I think it was very wise that both Ramón y Cajal and Golgi shared the Nobel Prize

Why Because somehow, although they were defending opposite hypotheses, they were saying the same thing

on the one hand Ramon y Cajal said that neurons were independent that there must be a gap between them We have seen that this is fundamental so that the information can be transmitted But on the other hand if there is no communication between them if this reticulum is not formed That network that Golgi defended that theory reticular If there is no such connection Between everything else our brain didn't have that Functionality that we give it nowadays

It is important That there is an individuality but it is So important that there is a connection between them Our whole brain itself forms a very complex net There is a network of neurons, but there is also a network of brain areas

It is important to know and to be clear That we have gone through a time in neuroscience when we were placing The functions of the Brain in different areas This was the era of localizationism here is the Memory here is the attention here is the vision, here is the hearing it is true that it is still maintained that there are areas of the brain that are more important than others In order to perform a task We are still talking about frontal cortex for attention hippocampus for memory But we always have In account What is We are referring to that zone as the most important part Brain to perform that task but for any task we perform, no matter how simple

That it is We always need a circuit A network of areas It's not just one area We have abandoned this concept of localizationism to enter into connectionism

that the network, the brain forms a very complex network where the Different parts of our brain always have What to interact The interdependence both among neurons and between neurons The different areas Cerebral is one of the most important concepts in the neuroscience today So when we study cognitive neuroscience or the neuroscience of emotions the neuroscience Well-being for example We do studies in the laboratories on people in humans when we are doing studies in humans we have to work with techniques that are not invasive

the studies that are done in animals because they allow to be able to record what neurons do Individuals But for this We have to do what is called intracranial recordings i

e

we open The skull And we put electrodes Inside the brain And only then can we know what What a neuron does What a small group of neurons do or what they do then A set Of neurons in a given area In human studies well obviously we can't open the skull alone For research reasons It is true that there are times that when an operation is being carried out of neurosurgery because they are allowed For research purposes It is allowed to put electrodes To know what the neurons do of human beings in particular These studies are obviously very, very, very scarce And then also Well, it has the peculiarity that they would allow to study only the brain of People who already in themselves Have an injury Therefore all the studies that treat Of cognitive neuroscience or neuroscience of emotions that is, the neuroscience that studies the behavior of human beings They are always studies that have been done measuring the brain since Outside Therefore when we are measuring The brain from the outside With neuroimaging techniques We speak Always from regions Of the brain We are not talking about neurons Why we can't measure the activity of a neuron From outside It is very very very very small We already have A lot of problems to measure how it is brain activity from outside because the field Electromagnetic measuring, emitting Our brain is very tiny and look it is so tiny it doesn't stop To give you an idea I tell you an anecdote The person who discovered the technique that Allows us to measure the electric fields of our Brain was Hans Berger In England he was stationed, he was a doctor he worked at the Hospital in psychiatry but during his military service He had an accident Some days later he received a letter from his sister where she told him A very disturbing dream that she had had and that described the Accident that Berger had had as follows This is because he had absolutely shocked Not to see how his sister, hundreds of miles away, could have known what had happened to him

When he finishes his military service he comes back to the hospital and devotes all his Efforts in trying to To study to discover the neural mechanisms of telepathy It was also a time not so very close to the wars where So to be able to study the communication between brains at a distance And transmitting that information was something because it was Vital and very, very valuable at that time Well, he was in the hospital, so A lot of hours to see how his brain is like an antenna

He had communicated with his sister's brain Little by little he begins to make experiments and Discover one of the techniques that has revolutionized and advanced neuroscience the most

What is encephalography That is to say It is a system that by means of electrodes Sensors that we place on the scalp Non-invasive method We can measure the electric fields measured by our brain Well, to poor Berger's misfortune what he discovered is that the electric fields of our Brain They don't travel one centimeter When we have to measure the electric fields of the volunteers that lend themselves to experiments for memorizing Doing by doing any task We have to have a lot of Careful In that there is no interference of any kind Electromagnetic gels must be used Conductors to amplify The signal Why Why the field electromagnetic that our brain generates is very tiny But also our brain is perhaps the most protected organ of the body It is surrounded by fluids It is surrounded by a membrane then it's got the bone, the skin, the hair So that when we want to measure the electromagnetic field of the brain from outside So we have to use techniques That are very sophisticated such as for example The Magneto encephalography which is based on super conductivity quantum To measure fields Magnetic which are of the order of centoteslas, 10 to -12 Tiny, tiny, tiny Electric fields the same They are very small Then poor Berger was left wanting to find out what the mechanism was underlying telepathy Why the electromagnetic field is very tiny When we We measure what you do what electricity our brain generates Well, we have sensors That measure the field Who has generated the brain from outside As we have said before the neurons has the capacity to produce discharges electrical That electric discharge is very tiny For a single neuron When we study the human brain What we measure by Example in a small piece is The number of electrical discharges that all neurons have produced that are under there and this may seem like a technical detail but it's not so much, it's talking about a The principles of neuroscience For us to be able to perform any task thousands And thousands of neurons They have to synchronize Thousands and thousands of neurons have to be like singing in a chorus It's not worth the activity of a single neuron, there are thousands and millions of them than singing in a choir speaking the same language

We imagine a brain not that we had here for example And here you have the cortex prefrontal cortex the cortex is everything that covers our brain that's finite with if we were to put 6 credit cards Actually the outer part of the brain is very very very very thin

Nowadays neuroscience continues to recognize that we are only conscious of that information that processes The cortex of the brain The cortex of the brain is represents almost nothing very very low percentage of what is The entire brain volume Let's imagine that we are paying attention to something We are not attending We are listening for example to the Sensations of our Breathing We're going to have a lot of activity in this part of here which is the cortex

prefrontal It is one of the parts most important parts of our brain We are going to talk a lot about it in the neuroscience of wellbeing The prefrontal cortex Almost the jewel in the crown so when we're paying attention to something all these neurons here are boom, boom, boom, boom Emitting electrical discharges At the same time They are singing in a choir But it's a choir that is very peculiar Because there is a part of the choir that is speaking in a language Another part that is speaking in another another that is speaking in another our brain speaks up to almost five languages it is said These five languages allow the brain to communicate With each other Then when we perform Any task Producing everything Those electric shocks For the brain it supposes an enormous amount of hemodynamic resources The brain produces very little energy But it consumes up to 20% of the energy that our brain produces

Body that compared to its small volume is the organ that consumes the most energy To do any task no matter how simple is a huge hemodynamic effort for our body

so here we have the frontal cortex Which as I say is very Involved in processes such as the maintenance of attention the regulation of our behavior The inhibition of our behavior Designing a strategy, this is the frontal cortex tremendously important Over here a little bit more to the sides we have The somato cortexes Sensory and the projection of memory areas Here in the temporal most lateral parts Our body is represented Because we have a representation Of all our body of the hands, of the face of our back of all the architecture of our body Over here if we could just stick our finger in this groove that leaves our ear when this bone is felt We have the insula The insula is one of the parts most important also in the neuroscience of well-being Because it is the one that tells us about who we are As I can observe myself Myself We have the most occipital or visual areas process a lot of information

In our brain Today, one of the most ambitious research projects there is It is the project that tries to discover The neural correlates of consciousness What this means What is the part of the brain most involved in the act of consciousness There is one in this project Two fronts trying to figure out which one is right There is a front that leads more Europe that says that consciousness would have more would give more place in the Front parts but there is another part of the project, the other side Who defends more U

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universities He says that consciousness would be more The occipital parts We'll see who Who is right We know that we have two hemispheres that are connected by a huge road map called the cayosian body

and it is important for us to know That in all the scientific literature we always talk about the zones in the singular we talk about the hippocampus, we talk about the insula, we talk about the cortex Frontal but of everything we have two okay, although we always refer to it in the singular If we open the brain and we could split it so that we can see The parts What they have inside Well, we find that inside in the deepest parts of the brain We have a whole structure Here it is called The pretty parts the emotional parts of the brain this is one of the most obviously important parts of the brain Why because they are the most involved in the memory But also in the emotional interpretation that we give To memory There is the hippocampus Which is so called because it's shaped like a hippocampus of a seahorse It is the most important for the memory people with Alzheimer's disease for example have atrophy in the hippocampus The emotional parts of our brain there is the amygdala the amygdala well it's a very tiny structure it is said to be the size of an almond Also from there its name It is one of the Zones that have the most power in the brain Why Because its biophysical activity and biochemical is able to reach To virtually all of the Structures of our brain It's the one that gives the emotional content to what we are living to our memories and our Experiences It's the one that reacts when we don't like something Most of all reacts very much when we are afraid of something When we have to defend ourselves when We feel Attacked What has been seen is that In people with chronic stress the amygdala grows So much in Its function as well as in its anatomy This leads to a bad Emotional management Within the emotional systems there is also the thalamus, and the thalamus so to speak is the distributor of information

It is the one that receives the information from all the senses, except the sense of smell

and it is the one that says Well, this information has come to me from the eyes For it is visual I send it to the visual parts This has come to me from the ears I send it to you to the auditory parts However, the sense of smell does not pass Through the thalamus Why because smell is one of the systems more Complex and the sense of smell is associated practically the whole anatomy of the emotional systems before at Anatomical structures of the emotional system It was called rhinoencephalon The sense of smell is for us a great manager of the emotions Within the emotional systems you see it as an umbrella here Gathering all the information from the Emotional structures is the cortex cingulate The cingulate cortex is going to be key also in the neuroscience of well-being

Why why is it the one that we Warns how We are Next to the island is the one that collects the information Of all Emotions is the one that picks up the Information From the body, and it's key, key to the interpretation of our experience

To live the experience more Full bark cingulate is going to be absolutely key and already inside we've talked about the cortex as the most superficial part of the cortex inside were the emotional systems this is a division anatomy As I say because then everything is functionally intertwined and going a little bit lower We have what is the Systems, what we call the reptilian system

the trunk of the encephalon the brainstem not that as its name says it is the brainstem that holds our encephalon It is the most visceral part, so to speak

more automatic More primitive but here is a zone which is especially important also in the neuroscience of well-being It's an area called the locus coeruleus

Because it is bluish and it is one of the areas most involved in respiration But not only in the breathing process But the one that tells our brain how we are breathing It is the key zone for the influence that the breathing has on our mental states So we have then a brain made up of neurons Which are independent but which are absolutely Intertwined We have a brain which is formed by areas They look independent but they are absolutely Intertwined and that the important thing about our brain for processing of the Information is not so much the components But the relationship between them