This has been a little bit different from the others, since we did not have any lecture, but we had only the exercise session on Tuesday. Also the exercise session was different! Indeed, we did not have a normal exercise session with some questions, but we went to a laboratory (actually the same visited in a previous excursion) and we performed ourselves an EEG (electroencephalogram). For this experiment it was possible to apply in order to be a volunteer for the EEG. None of us was a volunteer. Because of the number of participants, the experiment was performed twice with two different groups.
It has been really interesting to see finally how a real EEG is performed, in particular because we did some exercises related to this kind of medical application in other courses such as Principles of Biomedical Imaging. In this course we learnt how to reconstruct an image once the data have been collected. Now, with the experiment performed in this last exercise session we saw how the data are actually collected. We lost a little bit of time for the preparation of the experiment: in order to have the good conductance, we had to put some gel between the skin and the electrodes, but it was really difficult to dose the amount of gel! The real measurement did not take a lot of time. Unfortunately, the results we obtained were not very good, which may be due to some inactive electrodes or to some errors of other types. But it is not important, the most important thing was to understand the principle!
See you next week,
Laura, Leonardo and Hugues
This week we worked on learning about chapters 22 and 23 which speak about both the wiring of the brain as well as the structure and regions of the brain. It was really interesting to hear about ocular dominance shifts and how it can effect the vision of cats for example who have had occlusion of one eye for a majority of their early developmental life. We had no idea that a majority of the neurons will not be responsive in the occluded eye ever it is allowed to regain sight.
Unfortunately some of us missed out on doing the quiz this week but we appreciated you guys giving some students the opportunity to retake it because they hadn’t read both of the chapters.
We also had the opportunity to visit the Baba Center this week which is the Baby Brain Activity Center. According to their website, they have four key mission statements which include:
1) To understand the development of brain functions, and how illness and other adversities may affect infant brain development
2) To recognize atypical brain development at infancy
3) To develop new generation methods for infant brain studies
4) To serve as a hub of knowledge and bridge for collaborative efforts between hospitals, academic institutions, families, and businesses
It is really interesting to see an organization spending so much time working so heavily on understanding and diagnosing different problems that can arise in the earliest parts of infancy.
Thanks again for an interesting week!
Laura, Leonardo and Hugues
Today the title of the post might not be very appropriate since we didn’t have any lecture this week but anyway it’s our 9th post on this blog so let’s keep thing the same way as usual! So the lecture of this week was replaced by an excursion but in general it felt more like three little excursions because we visited 3 labs at the same time which is very convenient! The first one was AMI (Advanced Magnetic Imaging center) where we had the opportunity to learn a bit more about brain MRI techniques and instrumentations because we actually saw the MRI scanner and all the coils possibly used for this kind of imaging. The second lab was ABL (Aalto Behavioral Laboratory) in which we visited some rooms we behavioral studies can be leaded with for exemple eye tracking technologies or thermographic cameras. Finally we visited the TMS (Transcranial Magnetic Stimulation) laboratory. There we were shown that some areas of the brain can be activated or desactivated by sending electromagnetic pulses, we never heard about that before so it was really interesting to see that such things were possibles.
The following day we also had an excursion in Helsinki to visit a company called Sooma in the health innovation village. This company use a principle similar to the one we saw at the TMS laboratory to heal depression. It’s really nice to see that theoretical physics and biology can be used in real life for medical application. The presentation was a bit short I wish we could have learnt more about the mechanism and how the product really work but it was anyway a very good introduction!
In general the excursions are really well chosen even if it’s nice that we are also following the principle of biomedical imaging course so we can better understand the technical details.
Really looking forward to next week excursion at Baba center!
Laura, Leonardo and Hugues
This week we went through the motor system and how it is controlled by both the spinal cord and the motor cortex. The lecture started as always with the quiz about the chapter of the book we had to read to prepare for the lecture. The questions of the quiz were quite well organized and they were really useful to test our basic knowledge on the topic before the lecture. We are wondering what kind of question we will have in the final exam, something closer to the exercises question or to the quiz question?
The lecture was really interesting, notably because we had the possibility to go through the two chapters concerning the motor system and thus to have a good overview of the topic. It was particularly fascinating to learn about the several reflexes existing in our motor system. Everybody knows in general what a reflex is and everyone has tried at least once to trigger a muscle response tapping under the knee (knee-jerk reflex). Thus, it was satisfying to finally understand why we do this and why this “mechanical stimulus” should work. We did not even know that this test was made to test the intactness of the nerves and muscles in this reflex arc. Other interesting topics were the flexor withdrawal reflex, the Golgi organ circuit and the crossed-extensor reflex.
Looking forward for next week and the two planned excursions,
Laura, Leonardo and Hugues
This week we had the excursion to Elekta in Hakaniemi. It was nice that the teaching assistant walked with us from Kamppi so that we could easily find it since it wasn’t directly in the city center. We had the opportunity to hear from several employees about the products created at Elekta which are used throughout the world for MEG and EEG scans. These machines are primarily used for cancer treatment as well as diagnosis of brain disorders. It was really nice that they provided us with refreshments when we arrived and told us the story of how the company was founded essentially at a cabin in the Finnish country side. It was also really nice to speak and hear from a fellow student who is doing his dissertation with them and hear about how he is helping detect childhood brain disorders by creating a system for achieving clearer signals from moving children.
In class this week we learned about the auditory system. It was interesting to learn how our ears adapts to sudden loud sounds by using the attenuation reflex to avoid as much hearing loss as possible. Introducing audiovisual integration with the video about the guy saying the same sound but showing different visual ques was also really cool. We had never heard to the McGurk effect before. We completed a quiz in class this week which reflected the reading from this week quite well. There was a question about the ventral and dorsal pathways of the visual and auditory systems and how they relate to each other which was a little bit tricky.
Excited to see what next week has to offer.
Laura, Hugues, & Leonardo
As every week now, this one started with the quizz of 10 minute on the eye (chapter 9 of the book). The questions of the quizz were really precise and needed a really good comprehension of the topic. Maybe it’s wanted for those quizz to be hard but we feel like the questions are maybe going too deep in the subject since we haven’t got the lecture yet.
The lecture then started on the eye and visions topics. This subject is very interesting because the vision is a very complicated mecanism which allows us to do a lot of things since it’s one of the most important sense. Also, it appear that small damages in the optic nerves, chiasma or tract can lead to many different optical problems by cutting different areas of the visual field. A part of the lecture was about optical illusion, especially the one about the dress and the shoe and it’s really funny to see how different are the perceptions among the population.
The day following the lecture we had the exercise session. This one was like the second one, some open question about specific aspects of the course which was useful to help us understand the muddy parts. The last question of the exercise was about sound so we decided to wait for the lecture about the auditory system before doing it.
Since next week is the exam week let’s meet again in two week after our first excursion!
Laura, Leonardo and Hugues
Also this week we started the lecture with a quiz concerning neurotransmitters and their respective receptors. The quiz was not as simple as it would have seemed since there was a question asking what the functions of a signaling cascade are (–> in the case of second messenger pathways). The more obvious answer was the amplification of the signal, but it was not the only answer we should have written. Indeed, the signaling cascades are also important for the signaling at a distance, for long-lasting changes in the cell and for further regulation (all the chemicals involved in the cascade can be a good site of regulation of the signaling pathway). In addition, it is important to notice that it is not the neurotransmitter itself which determines if the synapse will be excitatory or inhibitory, but rather the receptor.
The lecture was a continuation of the previous one. The main topics were acetylcholinergic, catecholaminergic and seretoninergic neurons. It is very interesting to discover in detail how all these molecules and their pathways work. Sometimes it can be difficult to understand all the differences amongst these neurotransmitters and their pathways, which are often very subtle (we can mention for example the difference between the ACh, GABAa and Glycine receptors which are pentameric with the glutamate-gate channel which is tetrameric).
All these molecules play an important role in cognition, perception, attention, emotions and social behavior. It would be interesting to learn more about memory and the mechanisms which allow the long-term memories to exist.
This week we did not have any exercise session, since we were supposed to have an excursion in a laboratory, which has not been possible because of some timing reasons. We hope to do our first excursion soon!
See you next week,
Laura, Hugues and Leonardo
This week we had our lecture on neurotransmitters and neurotransmitter systems. Although the vitality of these molecules has been introduced in a number of our previous classes it was really nice to spend a bit of time learning exactly how the channels and pathways for some of the major neurotransmitter molecules work.
We do sort of feel that since these systems tend to be quite complex it would have been nice to maybe see a little bit more text and explanation on some of the slides. Although many of them are images from our text it helps when topics such as this are broken down a bit more because when we go back to study these materials for the exam we then wouldn’t have to completely reread the chapter in order to understand what the images in the lecture slides are telling us.
In the exercise session we had the opportunity to play around with a software program called Expyriment. Although our class struggled a bit with getting it to work during our actual exercise session it would be really nice to see a step by step tutorial or examples of what we were supposed to see using the program in MyCourses later this week. Also maybe having a reminder email telling us what we are required to bring in order to do the activities would be really helpful so we can make sure to be prepared for whatever is planned.
We also had a quiz this week on our reading which was a little tricky since the chapter was quite extensive and detailed. It might be helpful for future quizzes to sort of explain how the quiz will be structured so that those of us who read the chapter can properly prepare for the quiz (either maybe telling us it will cover the broader topics or that we should really focus on one section of the chapter for example) without having to memorize every single page of the chapter. It feels that if you just read the chapter and come in for the quiz it’s still extremely difficult to get perfect score which seems like it isn’t doing those students justice who are really trying to do well in the course.
Cheers! Can’t wait to see what next week will bring 🙂
Laura, Leonardo, and Hugues
The lecture this week started with a quick quiz of 5 minutes containing only multiple choice questions. What made it difficult for us was that some of the questions were about the classification of neurons (spinous or not, Golgi Type I or II, motor/sensory/interneuron), which was discussed in a very specific paragraph of the chapter we had to read. In addition, there was a question about Alzheimer’s disease, which was unexpected because of the fact that we haven’t spent much time discussing the biology behind Alzheimer’s disease yet.
The lecture was about action potentials (4th chapter of the course book) and synaptic communication (5th chapter of the book). We clarified the process of action potential propagation as well as the mechanisms of depolarization. In the picture below we can see the typical three phases of an action potential: the depolarization due to the Na+ influx, the re-polarization caused by the K+ efflux and the hyper polarization phase, which causes a “refractory period” making Vm more negative than the normal. The picture also depicts failed initiations, which indicate that to form an action potential the initial signal has to be strong enough to overcome the threshold.
We also learnt a lot about synapses and how they work. The main classification that must be done is between electrical and chemical synapses. The difference between them is in the way the signal is propagated: for electrical synapses there are the so-called gap junctions which allow an almost immediate propagation, chemical synapses on the other hand work by releasing some specific neurotransmitter molecules into the synaptic cleft. These will then bind to the receptors of the post-synaptic cell and induce the propagation of the signal. This difference is also the explanation of why the synaptic delay is present in the chemical synapses but not in the electric ones (there was a question in the exercises about the synaptic delay).
During the exercise session we went through few questions of the quiz. The assistants explained to us that all the possible choices we had in the question about Alzheimer’s disease were related to other neurological diseases (Parkinson, Multiple sclerosis, etc…). The other questions of this week were about the synaptic delay (as mentioned above), the action potential, glial cells and the Nernst equation. The latter was the most challenging, since we were asked to obtain the Nernst equation from the Boltzmann’s distribution.
See you next week,
Laura, Hugues and Leonardo
Now that school is back in session and the first week of this semester is behind us, both the organization of our classes and the expectations of our professors are finally starting to feel a bit more clear. This week we were introduced to the neuronal membrane, the structure of the brain as well as the propagation of messages across synapses.
Although understanding the composition of a membrane and the four tiers of protein structure are vital to understanding both their function and their value in the transmission of signals between neurons, we felt that perhaps just a tad too much of our class time was spent on reviewing these topics instead of discussing for example, the details of the phases of an action potential pulse or an example of how concentrations of potassium or the voltage in the membrane can be calculated. With this being said, for those that are taking this course with a background that is not so heavily based in biology, it was necessary and understandable that some review of cell and molecular structures might need to be done.
This week was also our first quiz and although we did our best completing the required reading assignment and reviewing our notes it would have been nice to see the topics of the quiz be covered at least a little in the previous lecture. It also felt as if the questions were very heavily weighted toward one part of the reading material and not the other (which is okay) but then makes us wonder whether in the future the quizzes will only be based on the readings from Iiro’s book..?
We also had the opportunity this week to build a model brain during our exercise session which was a pretty fun and interactive way to get hands-on with the structures of the brain. We were also able to almost complete the homework assignment during this session which was really convenient although it did seem a little tedious to spend so much time directly copying tables from the textbook into the answer for the third problem. This might be a great way for certain people to learn information but maybe next time we could be given the option of whether to do this task during the session instead of have it be a requirement for the homework for the week? That way those of us who learn better through just reading them via the book could avoid spending so much time copying vocabulary.
Looking forward to seeing what will be discussed in next week’s lecture as we slowly start to connect the dots between the delicate structures and complex abilities of the human brain.