This week we had our third excursion and we visited the Aalto NeuroImaging Infrastructure (ANI) in Otaniemi. Our group was divided into three smaller groups in which we were demostrated different topics. Some of the demonstrations and presentations were of old topics. For example we had a brief recap on transcranial magnetic stimulation in 10 minutes. We had previously gotten a quite extensive presentation on this topic at Nexstim but a little recap never killed anyone and it was nice to know that TMS is possible here in Otaniemi also. The second pitstop dealt with MRI.
For us the most interestin gvisit was to the Aalto Behavioural Laboratory. There we were presented modern eye-tracking methods and we even got to try them. It’s quite extraordinary that we can actually track someones focus of eye-sight. This also felt weird as we got to try it. Suddenly you’re very aware of where you are looking. Furthermore, we got a little demonstartion on lie detection. One of the group was instructed to write a number on a paper between 1-5 and then to lie of the written number when asked. The audience got to see the eletrcis responses of the liars body as she tried to get away with a lie. She wasn’t successful.
As a whole this week was pretty quiet in terms od this course, which is a blessing really. It seems like every other deadline on other courses strikes in the end of November.
– Pekko & Maria
This week started normally with a quiz and a lecture and on Tuesday we visited the Cognitive Brain Research Unit in the University of Helsinki. The chapter for the quiz was about the wiring of the brain. The topics were a bit more difficult than before in our opinion but the lecture after the quiz clarified some things. We for example studied the production process of neurons, which includes cell proliferation, migration and differentiation. On the cell profileration, precursor cells are neural stem cells. Immature neurons are called neuroblasts and they were pictured slithering upwards to the cortical plate through the subplate in the migration phase. At first this mechanism seemed quite strange. The whole neurogenesis process includes neural precursor cells production in the lateral ventricle area, migrating neuroblasts and finally newly generated neurons in the cortical plate. The neuroblasts always go on and form a new cortical plate, which then becomes a new layer. The differation order is neurons first, actrocytes second and oligodendrocytes last.
After the migration the neurons begin forming an axon and the axon travels from the gray matter to the deeper structures in the white matter. Guidance proteins either attract of repel the axon, which guides to axon into a correct direction. There was a good demonstrative video from youtube of this topic, which helped understanding this. There was also interesting information of the connection between neurotrophins and apoptosis. The survival of neuron depends on neurotrophins provided by target neurons and without the neurotrophins, apoptosis (systematic disassembly of a neuron) begins. Neurotrophins switch off the apoptosis.
The excursion was very interesting but seemed a bit rushed at times. First we visited the no interference room where the test subjects watch silent movies while their brain reactions are tested. After that we had a little presentation of the areas experimented in this unit. We found out that sounds development is affected by native language learnt as a child, particularly the difference between Finnish and Estonian language development. The difference was apparently due to the differing ö and õ sounds, which was interesting to know. We also saw how neural sound discrimination can be improved in dyslexic children using audio training game and a comparison of how MMN differs for different types of musicians. There also seemed to be a correlation between positive brain development and learning music, which was interesting. Furthermore, only listening to music is believed to improve verbal memory, mood and attention.
This week had a similar structure as the previous ones except that there was no exercise session for Tuesday. On Monday we begun with a quiz like before and this time there was only one chapter for studying. Sometimes the preparation for quizzes has been quite tough because the work must be done on weekends with numerous pages to be read. This time the workload was okay and we think we managed to study the chapters quite well. Also we think this might have been the first time none of the questions in the quiz were from review questions from the end of the book chapter although the questions there required quite long answers.
Chapter 15 dealt with chemical control of the brain and behavior. On the lecture we took a look at different neurotransmitter related pathways. It is useful to categorize different brain areas by the neurotransmitter used. For example we concentrated in the differences of acetylcholinergic and dopamine pathways. Also we returned to similar topics with the exercise two as we studied, which neurotransmitters are active in specific brain structures. In our opinion this recap came in a good spot as we’ve forgotten many of the studied brain areas and structures. For example we learned that Substantia nigra, striatum and nucleus accumbens are related to dopamine pathways. Also we learned that the first stages of Alzheimer’s occur because of the death of acetylcholine producing cells in the acetylcholinergic pathways a bit similarly as Parkinson’s disease is due to loss of dopamine producing cells in the Substantia nigra structure. Much of the topics we studied for the quiz were new information but there was something familiar too like the relation between pituitary and hypothalamus.
On the lecture we abruptly examined the differences between catecholaminergic substances. We already knew that dopamine, noradrenaline and adrenaline have similar origins but it came as a little surprise that their chemical structures are that similar. We are looking forward to the excursions, which might well be the most useful take from this course after all as we should probably begin planning for the future after university.
This week begun similarly with the previous one: we had a quiz. The quiz was about chapters four and five from the book and the topics included the action potential as a whole and synaptic transmissions. This time we had only five minutes to finish the quiz and some of the questions had a word limit of ten words which didn’t feel practical at all. This might have resulted in a worse performance than in the first quiz.
There were a lot of old and familiar information but also new. Basic properties of action potential; dividing it into phases of depolarization, repolarization and hyperpolarization and the fact that action potential transforms into a chemical form between neurons in the synaptic clefts was old information but a recap was useful because we had forgotten many details of this chain of events. Furthermore, the difference between agonists and antagonists was a useful recap and this topic as a whole is something to look forward to as the function of many modern day medicines are based on the manipulation of synaptic transmission.
The differences between resting membrane potentials in different cell types was new information for us although afterwards it seems quite obvious. We also found it interesting that the difference in the size of the diameter has such a big effect on the conduction velocity of an action potential. Myelin sheath obviously has a great influence but it was difficult to understand how the thickness of myelin makes a difference. We also learned about different types of synaptic transmission and whether the transmission is excitatory or inhibitory. An interesting example of inhibition was that hangovers are caused by body trying to excite the over inhibition of neurons after drinking alcohol. Learning about shunting inhibition and how to kill an action potential was new as well and quite interesting. Finally, the production mechanism of different neurotransmitter was new for us. It was fascinating to see that some of the neurotransmitter are actually created in the soma and how this chain of events leads to a complete product.
On Tuesday we had a brain composition session which supported our learning of different brain areas. This week had an exercise where we had to identify trillions of brain areas and structures. We think that the main input from this weeks exercises was that flash cards are going to be useful in our learning process of brain anatomy.
The first week begun with an introduction lecture and we also learned about the basic properties of neurons. In the beginning the lecturers shared their thoughts on the importance of brain research and we got an overall summary of the required actions on the course. The latter part of the lecture dealt mostly with basic functions of neurons.
Every week the lecture starts with a short quiz in the beginning and students are expected to prepare for these quizzes by reading given chapters from the course book. The first quiz is about chapters two and three: Neurons and Glia along with The Neuronal Membrane at Rest. These topics were already quite familiar for both of us since we’ve explored the basic functions of neurons and membrane potentials on previous courses as well as in high school. Of course we quickly realized that the text book had more specific descriptions on the topics. We found the classification of neurons and naming of different parts of the axon interesting as well as the introduction of stellate, pyramidal, spiny and aspinious cells. Furthermore, classifying of glia cells widened our knowledge. Previously we mainly only knew the names of different glia cells and whether they operated in the central or peripheral nervous system.
We’re looking forward to getting more information on the neurotransmitters and their influence on developing disorders and diseases. Also the chemical control of the brain and its impact on behavior is something that sounds intriguing.
– Pekko and Maria