Week 5

The fifth week’s lecture handled topics like acetylcholine pathways and how this is involved in perceptual learning; the norepinephrine and serotonin system; stress response as a result of the mechanisms of the autonomic nervous system and more. What was interesting to see was how each neurotransmitter’s pathways reach different parts of the brain, and how the excess or absence of one neurotransmitter can have unforeseen effects on the functioning of another.

The first task of the given exercise, which was handed out last week, was about finding a drug or disease that affects the central nervous system. It was intriguing to explore and find out for example how an excess of a chemical call tryptophol can completely disrupt the circadian cycle and as a result daily functioning. Through a disease called Sleeping Sickness (or African trypanosomiasis), parasites producing tryptophol enter the hemolymphatic system. Eventually the chemical crosses the blood-brain barrier. Tryptophol can be a functional analog to serotonin or melatonin which are involved in sleep regulation and as a result causes symptoms simulating the effects of excess melatonin or serotonin.

The second exercise was an experiment measuring reaction times to aural and visual stimuli made with a python program. Having studied computer science, I naturally went to check the code. The timing as randomized to make it so that you cannot guess when the stimulus will come. The results of the experiment revealed differences in the reaction times in the beginning and end of the study. Also overall reaction times varied between the two stimuli. The figure below displays these differences. More detailed explanation on how these results came about will be discussed in the next blog post.
reactions_graph

 

Neurotransmitters

Sadly the excursion that was planned for this week got postponed due to scheduling issues, so this week consisted of a lecture as well as an exercise session that was supposed to introduce the python-based problem.

After having studied the basic structure of neurons and the principles behind synapses the past couple of weeks, it was interesting to finally go a bit deeper into the topic and learn about neurotransmitters. The basic functions of them were introduced already in the previous lectures so this week dealt mostly on the classes they are divided into, the most common neurotransmitters and their functions. One of the most interesting topic was the recent studies on the function the opioidergic system plays on behavioral reinforcement and social behaviour overall. We take so many things as given; for example, it does not surprise us that alcohol might make us more social, and many times people use it as a way to become more social and feel more confident. Having thought it was primarily due to becoming more relaxed, it was fascinating to find out that it might be related to alcohol releasing beta endorphin, which again strengthens social behaviour by modulating the opioidergic processing in the brain.

Diving into the material

“Since it is the third week of this course, it is about time to take a look at the studying material! At the first lecture we were given the names of the three books used in this course, plus the lecture notes from Risto. I have to admit that having three books plus notes seemed a bit excessive and complicated at first. But it seems to be working out just fine: every week the reading required for the next lecture is clearly stated, and I don’t feel confused about the amount of the material at all. Especially this week I have relied only on the reading material, since I could not make it to the lecture or the exercise session, and I have grown very fond of the Bear, Connors and Paradiso’s book. It is a wonderful example of a great course book: everything is explained very clearly and with lot of pictures, examples and even metaphors to help the reader understand what is going on. These things make the book very easy to follow.

Chapters 3, 4 and 5 from the book (some of these things also covered in the lecture this week), talking about neuronal membrane at rest, action potential and synaptic transmission, gave a really solid and even detailed ground on which to start building on understanding the operational aspects of the human brain. This ground is made even better in the next lecture, when we will start talking about neurotransmitters. Then we are starting to really get into the stuff that I am mainly interested about as a chemist! This week has been and the next weeks will be very important in the sense that it is crucial to understand the way neural cells communicate in detail to be able to affect it somehow.

One thing I also particularly like about this course is that we are encouraged to use more imaginative ways for our learning as well. This week the materials section was extended with tips for helpful apps and flashcards. The 3D brain structure app is very useful especially for me! I sometimes feel that it is difficult to try to comprehend the complex structures of brain with the help of the the “normal” brain structure pictures, since they can only display a limited segment at a time.”

– The Chemist of the Team

 

Neuronal Functions and Play-Doh Brains

The content of this week’s lecture focused mostly on neurons, action potentials and how they propagate. A lot of the material was somewhat familiar through previous courses, such as biophysics, but a recap is never a bad idea.  It would, however, be interesting to hear more about different neurons, and if different types of neurons serve only certain functions; i.e. if some neuroimaging techniques measure mostly the activity of pyramidal neurons, do pyramidal neurons account for most of the cortical activity? Is measuring them an accurate representation of what is happening in the brain?
In addition to having a lecture in the beginning of the week, this week’s exercise session offered us a practical way to to study the structure of the human brain. At the beginning of the session we were given tubs of play-doh and told to construct a model of the human brain. We were guided to construct each section of the brain at a time, while going  through the main functions of the section we were modelling. This hands-on session was a fun way to explore the different brain structures and their sizes relative to each other, as well as getting to know one another. Moreover, it was fun to see what structures other students payed more attention to and how different the outcomes were.

Below are results of the first workshop session.3D-BrainModel

Introduction Round

Greetings to all readers!

This blog post serves as a learning diary for students taking the course Structure and Operation of the Human Brain. During the first lecture we went through an introduction to the subject and practical matters on completing the course. Also, students introduced themselves to each other in the lecture, telling their background and motivation to choosing the course.

Halfway through the week we formed a group for writing these blog posts. The group is formed of three students as follows:

Anastasia Lowe is a Biomedical Engineering student with an interest in neuroscience. She has taken a few courses on Cognitive neuroscience before and is interested in the structural aspect that this course deals with. For her bachelor’s degree she studied Bioinformation Technology.

Iiris Hakaste is a Chemistry and Biotechnology student. She is mostly interested in chemical reactions in the brain. She is very interested in how drugs affect brain activity, and what kind of molecules are able to do that at all. She wishes to work with pharmaceutical research one day, so she feels that it is important for her to understand the brain’s structure and functions to be able to design effective medicine.

Alison Tshala is also a Biomedical Engineering student. She studied Computer Science for her bachelor’s with Bioinformation Technology as her minor. Choosing Bio-IT as her minor pivoted her towards the Life Sciences track. With her CS background she still hopes to be able to adapt to the major and specifically to this course. Due to her programming background, she is interested to learn how to apply Matlab for the course’s exercises and more specifically on its applications to the operation of the human brain.

Each week that there is contact teaching, will be followed by a blog post so watch this space for our thoughts, questions and observations on what we learn!