My Little Grey Cells

This week we had an excursion to the Aalto NeuroImaging laboratory (ANI). The excursion was fascinating. It was nice to see what kind of research is done in Aalto in the field of neuroscience, because that is a field we are interested in applying our computational knowledge to. Especially the demos about various devices were super interesting and hearing about the actual research examples. The eye tracker was one of our favorites and it was interesting to see how it works and also how it is calibrated, as well as hearing about the detection algorithm, since we have a computational background. The infrared camera was cool and the example of measuring the breathing rhythm by looking at cold air going in and warm coming out. It was also amazing how the warmth from the hand on a notebook page can be transferred over 30 pages. It was interesting to hear these examples of what types of things can be analyzed using the devices because there are so many things that my imagination wouldn’t think of immediately. It was also great that the visit was interactive even though it was organized virtually and we got to vote on the “lie detector” number options and ask questions. The visit was well organized and maybe even better than in person because all could see everything in detail instead of some people being at the back and not being able to see. The visit was also inspiring when thinking about the future and possible PhD studies and career options.

Final exercises were also related to the ANI excursion. The first assignment was related to EEG measurement and reaction times. It would have been interesting to also see an EEG demo during the excursion, because it would have supported the exercise assignment better. During the excursion we saw the EEG cap and the electrodes, but that does not really help to understand the actual experiment and the results very much. But, nevertheless it was interesting to study the reaction times more from a different perspective and also use some imagination to design a hypothetical brain study using the techniques introduced during the excursion.

Overall the whole course has been very interesting and educational and our expectations have been fulfilled. The course covered the structure and operation of the brain well, but at the same time it meant a lot of new content. In addition to other courses during this fall, the amount of new concepts have been quite overwhelming and really challenged our little brain cells, but hopefully we have learned enough. The course was overall arranged very well and the course arrangement supported our learning. Our little grey brain cells thank you for the course!

Posted by Inka Lehtimäki

The topic of this week was the motor system and we had a lecture and an exercise session. The lecture discussed spinal control of movement as well as brain control of movement. We were somewhat familiar with the operation mechanism in skeletal muscles from a previous physiology course. Especially the sarcomere structure and how myosin pulls on the actin filaments to contract the muscle. It was interesting to hear how this is also dependent on calcium ions. It was a little bit confusing in the book that the intrafusal muscle fibers were drawn outside of the muscle, but it was good that it was explained in the lecture. However, it was interesting to learn how the nerves innervate the muscle and how the stretching of the muscle is observed and controlled. The concept of mirror neurons was interesting and especially that the action potentials are not fired if the human for example uses forceps instead of hands. Overall, the spinal control of movement was more familiar than brain control of movement already before, and it remained the same also after the lecture.

Exercise topic was also motor systems. The questions were again very applied but therefore also very interesting. The baseball question was especially interesting and we had not known or thought that the reaction for hitting the ball is actually not possible based on normal reaction times and decision making. It is obvious that training and learning improves the decision making ability and reaction time, but it was totally new for us that training and learning can alter neural pathways. The pathway for the physical movement based on visual input is different or shortened and is more based on reflex than actual decision making in the brain and commands based on that.

Now all the topics for the course have been covered in the lectures which causes mixed feelings. We have learned a massive amount of new things about the human brain, but we also feel that many things are still unclear. Good luck for us for the exam…

Posted by Maaria Malkamäki

The topic of this week was mental illnesses and we only had a lecture. The topic was very interesting because depression and anxiety disorders are very common and affect many people we all know. It is also a very important topic, because these diseases are very expensive for society because of diminished ability to work, we were surprised by the huge amount of costs these create. It was somewhat surprising to hear that depression is linked to increased stress activity. We would have thought that anxiety would be linked to increased stress and depression to be the opposite. It was also fascinating that the glucocorticoid receptors and the actual amount of receptors controls the functioning of the HPA axis and thus the stress response, and that the amount of receptors is affected by early childhood experiences (as well as genes, etc.).

While reading the book, we were surprised to learn how much schizophrenia genes affect the response and vulnerability to the environment which then can cause schizophrenia, in addition to the disease being purely genetic. We also realized how important it is to understand the normal functioning of the brain and chemicals related to that in order to understand mental illness fully as well as how to treat them properly. On the other hand, learning about mental diseases and their cause and effect in the brain helps us to understand how many things really work in a healthy brain and how changes in “small” things can have dramatic causes. 

It is also interesting to think about how the affinity of drugs affects the change in behavior and there was a nice figure about this in the book. When reading about the effects of neurotransmitters and receptors in previous chapters you could easily think that the effects apply to all of those receptors, but the effect depends of course on the affinity of the drugs for example.

It would be interesting to know the reason for these diseases being much more common in women than in men. Is there a clear biological reason or are there also societal factors that affect this. The method for measuring these statistics probably also affect the results, if for example women are more likely to seek medical help for their anxiety or depression and they are only logged there. Another question we asked during the lecture was whether maternal and paternal care in early childhood differ with respect to the glucocorticoid receptor development because the lecture specified maternal care. It would make sense that in humans any physical touch from either the mother or the father would have the same effect, but is there some maternal bond or chemicals that do something special. In animals this could be different because of the nature and “roles” of the mother and father.

We also continued the exercise this week and tried the test again with the new script containing the latency calculations. The keyboard latency values were quite confusing, because they were very small or even negative, or alternatively very large so that the adjusted reaction times were only a few milliseconds. We started to think that maybe the script and the computer detects only the sound of the release of the key press and not the start, so that it would think that the key press started only after the press was detected by the computer if the latency values were negative or very small. The values were also very different between the two of us which is very strange. All in all the values were very strange and caused much confusion.

Posted by Inka Lehtimäki

The topic of this week was wiring the brain and there was a lecture and an exercise session. Lecture was very good, clear and also entertaining. It discussed neural proliferation, migration and differentiation, as well as the genesis of axons. The elimination of unnecessary synapses was also discussed as well as neuroplasticity. It was very interesting to hear how the brain eliminates unnecessary and redundant connections to optimize the functioning of the brain and surprising how many neurons all in all are destroyed. We were interested to hear about neuroplasticity and Hebb’s hypothesis stating that “neurons that fire together wire together” because we have heard it many times in different contexts. It was nice to hear that it is at least somewhat true. It was fascinating to hear how the brain develops from a prenatal brain to an adult brain and that some neurogenesis also happens during adult age to enable memory and learning. Most of the neurogenesis happens early in life but it seems like so many skills are also learned during adulthood. Are the connections already there but they are just somehow rewired and refined during learning? Even though we knew about apoptosis, we were surprised to learn that apoptosis is genetically coded into all neurons and needs to be switched off by neurotrophins. The chapter was also a good recap of the visual system we studied before because it was used as an example. It’s amazing how the brain works and keeps functioning so well in so many people even though the wiring is so specific and it seems like so many things can go wrong.

The exercise sessions topic was central nervous systems disorders and reaction time related to aural and visual input. The assignments were again very applied. For the exercise session, the focus was on the reaction time assignment. It was a very interesting assignment and it was nice to get a chance to do a “real” neurological test and analyse its results by ourselves. The test tested the reaction time from input to sensorimotor action of pressing a key on the keyboard. We have not finished the assignment yet, so it will be interesting to analyse the results and see if the reaction time changes during the test and how it changes if it changes. The assignment required some python related installation, which is always complicated and problematic according to my experiences, so it was nice to get technical support during the exercise session.

Next week’s topic is mental illness and we are very eager to learn about it!

Posted by Maaria Malkamäki

The topic of this week was the auditory system. The basic structure of the ear was somehow familiar in Finnish but the terms were new in English and Latin. The mechanism of hearing and the auditory system was basically completely new for both of us, and it was very interesting to learn about it and understand this day-to-day phenomena in practise. The sound localization ability is also very fascinating. The basic idea that both ears are needed for horizontal localization was familiar, but it is incredible that our brain can recognize the interaural time and intensity differences so well that even a 2 degree localization difference can be recognized. The vertical localization was not familiar, and it was interesting to learn that the structure of the pinna is important in that, and that only one ear is enough for sufficient localization. Overall, it was interesting to learn more about the sound localization, especially because Maaria has lived her whole life with a person who is deaf in one ear and knows the practical issues it generates, but has not known the physiological explanations. The lecture also covered audiovisual integration. It was interesting to learn how the brain believes the visual input more than auditory in conflict situations and alters the interpretation to match with the visual input.

It was fascinating to learn about how the different frequencies are heard and understood. We have both played different instruments, so music is very important to us, and thus we found it especially interesting to learn about the mechanisms and principles behind hearing related to music. We have been wondering already before this course, what the neurological reason is for some people being able to sing in tune and many people cannot. These people are not truly tone-deaf, but while being able to hear the differences in melodies they cannot sing melodies completely correctly or together with other people. After searching the internet Maaria found an article on the topic called Poor-pitch singing in the absence of “tone-deafness”, which provided evidence for their hypothesis that poor-pitch singing results from sensorimotor “mistranslation” during imitation, i.e. the auditory representations of pitch are mapped onto incorrect motor representations for phonation. The poor-singer then might have in his/her mind the correct pitch, but when it is produced the result is not the same and correct, because of the wrong wiring of the brain to produce that pitch. The singer might hear that the result was not correct but cannot correct it.

Someone also linked the article Social Pleasures of Music in the lecture chat. This was an interesting article about the emotional and social aspects of music and how the brain activation is very similar to social bonding. All in all, the topic of this week was very interesting because hearing is so important in our everyday lives and also strongly connected to topics important for us. Therefore, it was also extremely interesting to learn the basics and apply these to the topics that interest us, such as music.

References:

Pfordresher, Peter & Brown, Steven. (2007). Poor-Pitch Singing in the Absence of “Tone Deafness”. Music Perception – MUSIC PERCEPT. 25. 95-115. 10.1525/mp.2007.25.2.95.

Nummenmaa, L., Putkinen, V., & Sams, M. (2020). Social Pleasures of Music. DOI: 10.31234/osf.io/y29cd.

Posted by Inka Lehtimäki

The topic of this week was chemical control of the brain and behavior. There was only a lecture this week and it focused specifically on the function of dopamine, serotonin and norepinephrine in the human brain. The lecture was very good and it was nice that the unanswered questions from the last lecture were answered in the beginning of this lecture. The short videos about the topics were very good.

It was interesting to learn about the functions of dopamine, serotonin and norepinephrine in more detail because they are often talked about in everyday life. The diffuse brain systems related to them as a concept was still new. It was also interesting to learn about how these chemicals regulate very mundane processes like thirst. The lecturer mentioned that long-term stress degenerates the hippocampus. We were left wondering if and how the hippocampus can be regenerated and how much of the hippocampus can be degenerated. The function and operation of hypothalamus was already familiar for us from physiology, including the homeostasis and the co-operation with the kidney. It was interesting to also learn about how the same chemicals and their regulation cause Alzheimer’s disease and Parkinson’s, especially because these are such common diseases and we know people who have them, which allows us to really reflect on them and put them into context. We are now in the halfway point of the course and there is already quite a lot of memorization and terminology especially with the latin words, but hopefully we have already passed the halfway point in the topic point of view. However, the upcoming topics seem very interesting and we are keen to learn about them.

Posted by Maaria Malkamäki

The lecture topic of this week was neurotransmitters and the exercise session was on chemical senses and the visual system. Having one chapter as pre-reading for the lecture was a good amount of reading and allowed the lecturer to cover the important topics in more detail and more clearly, as well as answer some open questions. It was nice after last week to be really able to read the whole chapter and take notes and be well prepared for the lecture. The quiz was also good and we felt that we understood the main parts of the topic because we were able to answer the quiz properly, even though we misunderstood some of the questions and accidentally answered wrong. Overall, based on the lecture and the quiz we felt that we are back on track again somehow and maybe we are not doomed with this course.

The neurotransmitter systems seemed very interesting, and it was interesting to learn that the receptor binding is in some cases very specific but on the other hand not always. For example different ACh receptors, such as the nicotinic and muscarinic receptors, both bind ACh but they only bind nicotine or muscarine. It was also fascinating that the same neurotransmitter might have a different effect on different parts of the body, for example ACh in cardiac muscle and in skeletal muscles.

Like mentioned, the exercise was from last week’s topic. It was very good to have an exercise on the visual system especially, because it was not thoroughly understood last week. The exercise was in a way quite different from exercises we are used to from other courses, because the questions were very applied and you really could not answer them properly just based on the book, even if you would have understood the topic very well. The questions had many terms that were not introduced in the book or during the lecture, and it was basically the point to search the answers from google. It was not bad but just different. On the other hand, it was interesting to also learn some extra information compared to the book through the exercise questions. Especially the question about differences in the cephalopod and vertebrate eye was very interesting and educating, and helped to understand the function of the human eye also better.

Source: Bear, Connors, Paradiso: Neuroscience: Exploring the Brain, 4th edition, Lippincott, Williams & Wilkins, 2015, p. 155.

Posted by Inka Lehtimäki

The topics of this week were chemical senses, gustation and olfaction, and the central visual system. This week we had only one lecture but that lecture was all the more intensive. Having three chapters for one week and a single lecture was a lot of content. Our own schedule did not permit us to prepare properly for the topic, but it was also simply too much for one lecture. The whole lecture was just running from slide to slide without proper explanations and the whole picture of the topic and lecture was very messy. We would have wanted clear emphasis on the most important parts and a more detailed explanation on those parts, instead of having all the pictures from the book without understandable explanations. The quiz was also a lot harder this week compared to previous weeks.

The topics themselves were interesting and very practical in our everyday life. The functioning of our chemical senses was completely new to us and it was interesting to learn new details about the processes such as the fact that the process of smelling does not actually happen in our nose, but high up in the nasal cavity in the olfactory epithelium. Also, we always thought that the taste buds are the ones you can clearly see on your tongue, but turns out that they are papillae and that the taste buds are actually much smaller. We were also surprised to learn that their lifespan is only two weeks. Although this information was all new to us, it was quite easily understandable due to our background in chemistry.

We already knew the structure of the eye, the physics behind vision and how light is refracted, but it was interesting to learn also more about the cell biology and chemistry of the retina and how the messages are delivered to the brain. The message delivery would have been very interesting and probably also important to understand thoroughly, but we had not learned the whole anatomy of the brain and all the latin names for the parts yet, so it was hard to understand and internalize the system in such a short period of time. It would have required much more time, and with that being the last chapter of the three, there was not enough time to concentrate on that chapter and topic in our own preparation nor in the lecture. This week threw us straight to the deep end with a massive amount of new content like we suspected last week, but the shift from previous weeks was still a surprise.

Posted by Maaria Malkamäki

The topics of the lecture this week were the action potential and synaptic transmission. The basics of action potentials and synaptic transmission, both electrical and chemical, were familiar to us from our previous physiology and biology courses. However, the lecture and the chapters in the book gave us a deeper and more detailed understanding of the underlying processes. There was a lot of biochemistry, including the transportation of neurotransmitters in vesicles and their release into the synaptic cleft as well as their binding to the receptors to create an action potential in the postsynaptic neuron. Our previous knowledge of biochemistry and surface chemistry aided our learning greatly. It is nice to notice that even though we do not have an extensive background in physics, our knowledge from chemistry is a useful asset for this course and seems to be an important basis for understanding the structure and operation of the human brain. There were also some new and surprising facts, for example that in reality one neuron produces and uses only one type of neurotransmitter and thus has only one task. It seems very logical now, but our previous knowledge was more about the overall structure of a neuron and an overview of the different neurotransmitters, which left room for inaccurate interpretations. The lecture was easier to follow and understand this week compared to the last week and gave new insights to the topic, including the previously mentioned example.

The exercise session was in the form of a lecture this week. The topic of it was brain anatomy, which was interesting and very important for the course. Some very basic structures of the brain were familiar to us, but those also mainly in Finnish, so overall the exercise lecture had a lot of new terminology and facts. It contained a massive amount of new Latin words and also new English words and two hours was not nearly enough to understand and internalize them all. It requires a lot of work outside of the lecture to learn them and their functions. The exercise session contained a few breakout room sessions, where the idea was to draw or build the discussed brain structures and thus learn them better. The idea was good, but the remote implementation through Zoom made it very hard and the sessions were so short that it was impossible to complete the tasks there. Therefore, the learning remained quite superficial. Overall, it was very good to have this session, but it was not enough to actually learn and understand the topic. In the upcoming weeks, the topics of the course will be more about the operations of the brain, which are probably newer for us and the familiar parts are then mostly behind us.

Posted by Inka Lehtimäki

The topics of the week were the structure of neurons and glia, the neuronal membrane at rest and properties of the action potential. Most of the structural properties of the neuron were already familiar to us from molecule and cell biology courses as well as a physiology course, but this was a good recap. The biochemistry of the cell membrane, as well as behaviour and interaction of polar and nonpolar molecules in different solvents and between each other was common knowledge for us based on our bachelor studies. It was extremely useful that this first part was more familiar to us because this allowed us to understand the operating mechanism of the action potential more effectively as we did not have to spend as much time understanding the biochemical properties. The basics of the action potentials were also surprisingly familiar from earlier studies but more depth of understanding was obtained by reading the chapter 4. One question that remained unanswered, however, was the mechanism of releasing the contents of the vesicles into the cytosol when it does not fuse with the membrane and release the contents to the synaptic cleft or to other cell compartments.

During this week we had a lecture and an exercise session. The topic of the lecture was interesting, but having read chapters 2 and 3 before the lecture there was not much new information given on the lecture and some questions remained unanswered. On the other hand, the end of the lecture was very hard to understand because we had not read that chapter yet and the pace was very fast. Overall, we would have hoped that the lecture had explored the topic more in depth as we had already read the basics from the book. The exercise session was a useful introduction to the exercises and an opportunity to ask questions. It would have been even more useful if we had had a chance to complete some of the exercises and had already some more specific questions. The exercises themselves were quite a good balance of basic exercises and more difficult ones. Deriving the equation was especially challenging and remained still unclear. 

This understanding of the neuronal membranes and their function in facilitating the action potential in the small scale allows us to apply this knowledge to the larger scale to understand the operation of the brain and support our journey to understand the communication between our little grey cells. All in all, it was very interesting to apply existing knowledge from different courses and combine these to understand a new topic and application of the existing information. 

Posted by Maaria Malkamäki