Week 4 Exercise session

And again about the exercise session 🙂

Last week we were running a short experiment measuring the response time for aural and visual stimuli by using special application Expyriment. The process was interesting itself, but what was absolutely unexpected were the results. I’ve run the experiment 7 times, got quite controversial results for both types of stimuli, and the rest of the session was trying to understand this data with the help of professor Marko Havu and course assistants.

These exercise sessions do really motivate me to learn more, to try to find answers and explanations by revealing the questions and making me stuck.

Week 3

Today’s lecture was dedicated to the Synaptic Transmission. We were studying related terms and definitions (gap junction, neurotransmitters and their 3 types, absolute and relative refractory period, EPSP, IPSP, etc.), classifications and mechanisms and different methods of research (optogenetic, for instance). The difference between chemical and electrical transmission was explained (electrical synapses are bidirectional and they are faster). Then, since the majority of synapses are chemical the rest of the lecture we were studying them only.

Week 3 Exercise session

Couldn’t resist mention our second exercise session. We had a chance to try to make a 3d model a brain while listening the lecture of professor Marko Havu about the brain structure and its main parts. That was very crucial for me to be able to rebuild the whole thing from the scratch, step by step, since the final pictures of the brain in the books usually look too sophisticated and complicated to me (not to say messy :-))

(No no, I will not dare to post photos of my masterpiece here, but it was a great experience. And very beneficial in terms of understanding its spatial structure, inner organization and proportions.)

Thank you for this experience

Week 2

Week 2 was started with a short quiz of about 7 questions. The quiz was not that difficult since I have been reading the book and making my notes during all the weekend. Besides that, I have to say that I like a lot this kind of activity since it activates attention and forces to recall randomized parts of your new knowledge very rapidly – all the new information from the previous week in 5 minutes only.

After the quiz, the lecture has started. This week we had two lectures: Iiro Jääskeläinen and Risto Ilmoniemi were lecturing together. So. the lecture became not a monologue but a dialogue between two neuroscientists, which encouraged the audience to participate in the conversation.

We were studying the mechanism of AP, all it’s phases in details (rest state- stimuli-threshold-depolarization-peak-repolarization-hyperpolarization-resting state). Then, we went through different types of classification of synapses (electrical-chemical, axon-axonic/axon-dendritic/axon-somatic). Besides that, we were given the explanation of neurotransmitter transmission, we have learned where and how transmitters are synthesized, where are they stored, released and destroyed.

Reflections on the Lecture 1

Since my owner is not from the field (her background is architecture) I have learned a lot of new from the first lecture. Well, almost everything was new. It was crucial to get the general overview about my structure of brains. I have learned about Broadman’s areas, types of brain cells (which are not only neurons – surprise!), types of neurons and general understanding about how do I work.

So, here are some keynotes.

 

The brain is a system which could be studied on different levels: as a physical system, chemical system, biological system.

The brain receives information, interprets it, then stores, transforms it, then produces knowledge, and finally gives an output, which is expressed in the control of the body.

The brain has well-structured task-division management. The brain consists of 4 main areas (frontal lobe, pariental lobe, occipital lobe, and temporal lobe), which are subdivided into 52 areas of the brain surface, so-called Broadmanns zones (or Broadmanns areas). These zones have their fixed numbers. Each zone is responsible for a particular kind of tasks. For example, zone number 4 is responsible for movements, 3 – for skin sensors, 17 – for vision, 41- for hearing, 44 and 45 – for language, etc.

The brain consists of two main types of matter: gray and white, approximately in 50/50 proportion. Gray matter is on the top, and white is inside. Gray matter of the brain (cortex) is covered with gyri. Gyri is on top of convolutions, it covers all the surface of the brain. Sulci is inside

Brains could be studied on different levels, from the level of elementary particles (strings), through atomic physics, chemistry, molecular biology, cytology, physiology, anatomy, phycology, sociology, etc.

 

One of the Pioneers of the brain research was Santiago Ramon Y Cajal (1852 – 1934), who was studying brain cells with a microscope and making hand-drawings of brain cells. He was the first who defined different types of cells.

Neuron types:

  • unipolar cells (one input/output),
  • bipolar cells (two dendrites – for input and output separately),
  • multipolar cells,
  • pyramidal cells and
  • stellate cells.

Gray matter consists of cell bodies, unmyelinated axons, dendrites and glial cells. White matter consists of myelinated axons.

Glia (from “glue”) consists of astrocytes (which are not neurons, but between them), it fills most of the space in the brain that is not occupied by neurons and blood vessels. Glia transports “food” for brains, from blood to cells.

Synapse is a connector for information transfer, it’s a connector between two cells to pass a signal from presynaptic axon to post synaptic. Sygnal goes through synapse only in one direction. Astrocytes – is one type of the glia. Second type is Oligodendrocytes, which wrap around cell for electrical insulation. Axons are surrounded with many layers of oligodendrocytes. This insulation is called myelination, axon covered with oligodendrocytes is a myelinated nerve.

Neuron is an “adding machine”, it adds the input multiplied by synaptic strength. Tens of thousands of inputs comes into one cell. And synaptic connections are changing permanently. This mechanism is called neuroplasticity, and is one of the mechanisms of learning.