Let Us Put Our Brains in the Spotlight – Literally!
(2023) MOBK10 20231Degree Projects in Molecular Biology
- Abstract
- Neurons are the working force in each vertebrate’s nervous system. These small cells have the important task of transferring information in the form of electrical charges called action potentials. Neurons make it possible for us to sense touch, process our environment, and store memory. To conduct studies on the brain outside of the body, one can culture neural cells in the lab. However, to accurately replicate our brain through cultured neurons is easier said than done. The formation of arbitrary networks must be accounted for when trying to emulate our inner environment. Arbitrary networks are not representative of the network activities found in vertebrate brains.
In my work, I have been trying to solve these random network... (More) - Neurons are the working force in each vertebrate’s nervous system. These small cells have the important task of transferring information in the form of electrical charges called action potentials. Neurons make it possible for us to sense touch, process our environment, and store memory. To conduct studies on the brain outside of the body, one can culture neural cells in the lab. However, to accurately replicate our brain through cultured neurons is easier said than done. The formation of arbitrary networks must be accounted for when trying to emulate our inner environment. Arbitrary networks are not representative of the network activities found in vertebrate brains.
In my work, I have been trying to solve these random network formations by seeding human neural cells in microfluidic devices, a labyrinth for cells. The principle of culturing neural cells in a microfluidic device with a chevron pattern made up of a V-shape is to lead cellular growth in a desired direction. When the cellular growth is under control, it may be possible to activaley create the types of network more representative for our brain. For instance, I have tried to form feedforward networks in microfluidic devices. A feedforward network is a sleek organised structure where information is transferred from one layer of cells, through one or several hidden layers of cells, and eventually reaches an output layer of cells. My results point to the cell’s viability is almost as good as when they grow freely. The activity is similar and the cells’ growth is alike. The cells are also able to follow the chevron pattern in the desired direction and with a little tweaking of the design we expect to be able to better steer their growth and enable the formation of more representative networks.
Another aspect of my thesis was to evaluate the possibility of utlising optogenetics to these cultured neural cells. Optogenetics is a useful method to study and manipulate behaviour of animals and even singular cells. By transfecting the cells with the protein opsin, which is sensitive to light, it is possible to expose the cell to a visual stimulus wheruopon the cells open membrane channels and an action potential is elicited. Being able to control the amount of action potentials generated, we could potentially control how cells store memory. The information in form of memory is stored in the connections between neurons. One way to strengthen the connection is to generate multiple action potentials, which is possible with optogenetics. In my work, I found that it is possible to build an experimental setup and expose cells to visual stimulus as I simultaneously record the cellular activity. However, I did not add the opsin protein to the cells, meaning they were not actually sensitive to light. For future experiments, the opsin transfection should be performed to sensitise the cells to light.
To conclude, my work covers some basic ground for further future studies. With my chevron patterned microfluidicdevices I was able to steer the cellular growth. The cultured cells therefore exhibit potential to form feedforward networks with strong connection between the cells. When applying optogenetics to these cultured cells in coming experiments, the possibility to study memory formation in these networks will be possible. To manually strengthen the connections between the neurons in the created networks by using light, the prospect for memory research on mammalian brains outside of the body will open many doors. (Less) - Popular Abstract
- Let Us Put Our Brains in the Spotlight – Literally!
The brain is mysterious and we have much to unravel about it. I don’t have any means of solving it all in my thesis, but I hope to come just a smidge closer to some answers. The topics tackled in my project are immensely complex and one could easily fall down a rabbit hole reading about it simply because it is so fascinating. Our intriguing organ located in the centre of our heads does so much with so little. Our brain makes it possible to see the faces of our loved ones, listen to our favourite songs, and create beautiful memories. I have decided to dive into the last thing mentioned: memories.
Memory, in simple terms, is our brains' way of preserving and recovering information... (More) - Let Us Put Our Brains in the Spotlight – Literally!
The brain is mysterious and we have much to unravel about it. I don’t have any means of solving it all in my thesis, but I hope to come just a smidge closer to some answers. The topics tackled in my project are immensely complex and one could easily fall down a rabbit hole reading about it simply because it is so fascinating. Our intriguing organ located in the centre of our heads does so much with so little. Our brain makes it possible to see the faces of our loved ones, listen to our favourite songs, and create beautiful memories. I have decided to dive into the last thing mentioned: memories.
Memory, in simple terms, is our brains' way of preserving and recovering information encoded in neural connections. Our neurons can recognise patterns perceived from stimuli of light, sound, touch, and many other things. These very tiny cells have a power of information transferring much more capable than a supercomputer. And the more these neurons send information to each other, the stronger they become. This is the idea behind feedforward networks. Neurons in a feedforward network work in a sleek organised manner to optimise each other.
I have created an outside of the body model of a feedforward network by using small silicone-based labyrinths. These labyrinths have a pattern where cells will only be able to grow in one direction and stopped if they grow the other way (Fig. 1). The idea is that the neurons will grow much further on the “right” side of the labyrinth represented by the yellow arrow in the figure, than on the “wrong” side represented by the blue arrow. However, the attachment of the labyrinth to glass was a harder task than expected and the cells grew surprisingly far the wrong way due to the silicone detaching on the sides. On a positive note, they seem to follow the chevron pattern and grow nicely along the sides of the V’s that are attached correctly, as they’re supposed to. There is still more to perfect with this method, but when it’s working as it should, it will be a great way of representing the brain outside of the body.
Another part of my project was to evaluate future application of optogenetics to neural cells. Optogenetics is a useful tool in biology with diverse areas of use. If you add the protein opsin to cells, you will be able to control them with light. It’s like using a remote control for cells, but instead of switching on a TV you’re activating neurons. If you were to show a stimulus consisting of light flashes to neurons with opsin in them, they will in theory start to remember the pattern. It’s like you remembering the words to a song. Eventually, they might be able to predict when the stimulus is going to happen, just like neurons do in the actual brain. In combination with growing the cells in the pattern mentioned above, we are one step closer to representing and carrying out experiments on the brain without having an actual brain in the lab.
To conclude, there is still more to develop in the methods I have used in this work. Among other things it is important to create labyrinths that functions well and to get the optogenetic setup to work with finesse. The theory behind the thesis still stands strong and I believe with some fine adjustments, we will be able to conduct impressive studies on neurons. Not only to overview the formation of memory but also to create a more life-like model of one of our most important organs – the brain.
Supervisor: Fredrik Johansson and Carl-Johan Hörberg
Bachelor’s Thesis, 30 Credits in Molecular Biology 2023
Department of Biology, Lund University (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9146728
- author
- Karjalainen, Elsa
- supervisor
- organization
- course
- MOBK10 20231
- year
- 2023
- type
- M2 - Bachelor Degree
- subject
- language
- English
- id
- 9146728
- date added to LUP
- 2024-01-24 14:34:00
- date last changed
- 2024-01-24 14:34:00
@misc{9146728,
abstract = {{Neurons are the working force in each vertebrate’s nervous system. These small cells have the important task of transferring information in the form of electrical charges called action potentials. Neurons make it possible for us to sense touch, process our environment, and store memory. To conduct studies on the brain outside of the body, one can culture neural cells in the lab. However, to accurately replicate our brain through cultured neurons is easier said than done. The formation of arbitrary networks must be accounted for when trying to emulate our inner environment. Arbitrary networks are not representative of the network activities found in vertebrate brains.
In my work, I have been trying to solve these random network formations by seeding human neural cells in microfluidic devices, a labyrinth for cells. The principle of culturing neural cells in a microfluidic device with a chevron pattern made up of a V-shape is to lead cellular growth in a desired direction. When the cellular growth is under control, it may be possible to activaley create the types of network more representative for our brain. For instance, I have tried to form feedforward networks in microfluidic devices. A feedforward network is a sleek organised structure where information is transferred from one layer of cells, through one or several hidden layers of cells, and eventually reaches an output layer of cells. My results point to the cell’s viability is almost as good as when they grow freely. The activity is similar and the cells’ growth is alike. The cells are also able to follow the chevron pattern in the desired direction and with a little tweaking of the design we expect to be able to better steer their growth and enable the formation of more representative networks.
Another aspect of my thesis was to evaluate the possibility of utlising optogenetics to these cultured neural cells. Optogenetics is a useful method to study and manipulate behaviour of animals and even singular cells. By transfecting the cells with the protein opsin, which is sensitive to light, it is possible to expose the cell to a visual stimulus wheruopon the cells open membrane channels and an action potential is elicited. Being able to control the amount of action potentials generated, we could potentially control how cells store memory. The information in form of memory is stored in the connections between neurons. One way to strengthen the connection is to generate multiple action potentials, which is possible with optogenetics. In my work, I found that it is possible to build an experimental setup and expose cells to visual stimulus as I simultaneously record the cellular activity. However, I did not add the opsin protein to the cells, meaning they were not actually sensitive to light. For future experiments, the opsin transfection should be performed to sensitise the cells to light.
To conclude, my work covers some basic ground for further future studies. With my chevron patterned microfluidicdevices I was able to steer the cellular growth. The cultured cells therefore exhibit potential to form feedforward networks with strong connection between the cells. When applying optogenetics to these cultured cells in coming experiments, the possibility to study memory formation in these networks will be possible. To manually strengthen the connections between the neurons in the created networks by using light, the prospect for memory research on mammalian brains outside of the body will open many doors.}},
author = {{Karjalainen, Elsa}},
language = {{eng}},
note = {{Student Paper}},
title = {{Let Us Put Our Brains in the Spotlight – Literally!}},
year = {{2023}},
}