Here you can read about everything that's happening in the ISB Group.
Last week some of us (Gunnar, William, Christian, Fredrik and Thea) went to Gothenburg to attend the Second Swedish Diabetes Summit. It’s a summit bringing together basic and clinical research.
We had a good time listening to some really interesting presentations with topics varying from treatment of metabolic diseases to artificial intelligence in health and diabetes. Gunnar was chairman for the session of AI and he and William also presented a poster each.
/Thea
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In october, I went to Barcelona to attend the annual meeting of the European Society for Magnetic Resonance in Medicine and Biology (ESMRMB). Gunnar also came for one day. I presented a poster about my work modelling liver function. I also presented a poster and gave a short “lightning talk” on behalf of Mikael Forsgren, who could not attend.
/Markus
A couple of weeks before defending a thesis, it is common that the PhD student nails their thesis to a log in some of the common areas of the university. This is done to annouce that the student intends to defend their thesis and that anyone who wishes may read it and attend the defense to ask questions. The nailing is then celebrated with delicious cake.
I, Karin Lundengård, have now nailed my thesis ”Mechanistic Modelling – a BOLD Response to the fMRI Information Loss Problem” and I will defend it on the 30:th of November, 13.15 in Hugo Theorells sal (Northern Entrance, Floor 9). My opponent will be Kamil Uludag, Associate Professor at the Faculty of Psychology and Neuroscience at Maastricht University in the Netherlands.
Anyone who wants to attend the defense is welcome.
The full thesis is available at the following link: https://doi.org/10.3384/diss.diva-142870
English abstract:
Functional Magnetic Resonance Imaging (fMRI) is a common technique for imaging brain activity in humans. However, the fMRI signal stems from local changes in oxygen level rather than from neuronal excitation. The change in oxygen level is referred to as the Blood Oxygen Level Dependent (BOLD) response, and is connected to neuronal excitation and the BOLD response are connected by the neurovascular coupling. The neurons affect the oxygen metabolism, blood volume and blood flow, and this in turn controls the shape of the BOLD response. This interplay is complex, and therefore fMRI analysis often relies on models. However, none of the previously existing models are based on the intracellular mechanisms of the neurovascular coupling. Systems biology is a relatively new field where mechanistic models are used to integrate data from many different parts of a system in order to holistically analyze and predict system properties. This thesis presents a new framework for analysis of fMRI data, based on mechanistic modelling of the neurovascular coupling, using systems biology methods.
Paper I presents the development of the first intracellular signaling model of the neurovascular coupling. Using models, a feed-forward and a feedback hypothesis are tested against each other. The resulting model can mechanistically explain both the initial dip, the main response and the post-peak undershoot of the BOLD response. It is also fitted to estimation data from the visual cortex and validated against variations in frequency and intensity of the stimulus. In Paper II, I present a framework for separating activity from noise by investigating the influence of the astrocytes on the blood vessels via release of vasoactive sub- stances, using observability analysis. This new method can recognize activity in both measured and simulated data, and separate differences in stimulus strength in simulated data. Paper III investigates the effects of the positive allosteric GABA modulator diazepam on working memory in healthy adults. Both positive and negative BOLD was measured during a working memory task, and activation in the cingulate cortex was negatively correlated to the plasma concentration of diazepam. In this area, the BOLD response had decreased below baseline in test subjects with >0.01 mg/L diazepam in the blood. Paper IV expands the model presented in Paper I with a GABA mechanism so that it can describe neuronal inhibition and the negative BOLD response. Sensitization of the GABA receptors by diazepam was added, which enabled the model to explain how changes to the BOLD response described in Paper III could occur without a change in the balance between the GABA and glutamate concentrations.
The framework presented herein may serve as the basis for a new method for identification of both brain activity and useful potential biomarkers for brain diseases and disorders, which will bring us a deeper understanding of the functioning of the human brain.
This
autumn, we welcome another new student in our group: Josef Grännö
Hello, my name is Josef, I study medicine, and
I’m here at ISB Group to do a project for my 6th semester.
My project is about glycemic management in
patients admitted to the intensive care unit. During my time here I will
compare different models that aim to be used as decision support systems to
help ICU staff maintain the patient’s glucose levels in optimal range. I
collaborate mainly with the GlucoSafe group that is based in Aarhus, Denmark.
When not desperately trying to understand
mathematics I enjoy the outdoors, volleyball and amateur acting.
This autumn, we welcome another new student in our group: Christian Simonsson
Hi!
My name is
Christian Simonsson and I will be doing my master thesis here in the ISB-group.
I am a 5th year engineering biology student with my master’s profile
being Materials and Sensors in Biomedince. For my master’s thesis I wanted to
do something a bit different from what I have been doing the last two years. Since
my Bachelor’s project was on the topic of systems biology, and since I have an
interest in modeling (in biology and physiology ), I was very pleased when I
was given the opportunity to do my thesis here in the ISB group.
Adiponectin, which is a hormone released by mature
adipocyte has been shown to have an important role in the development of type-2
diabetes. However, the precise underlying mechanisms for the production and
release of such hormones in adipocytes are not fully understood. Therefore, an
ongoing project in the ISB group has been to use mathematical modeling to
describe the exocytosis of white adipocytes to predict adiponectin secretion,
making it possible to quantify the exocytosis and endocytosis rates. An article
on the subject was recently published by William Lövfors et al and in my
project I will make use of the model presented in this article. The goal is to
extend the model to also describe the experimental data for adiponectin
secretion induced through the activation of beta-adrenergic signaling pathways
upon extracellular adrenalin stimulation. Hopefully this might contribute to
creating a more complete framework for understanding the regulation of this
important metabolic hormone.
This autumn, we welcome another new student in our group: Victor Viberg
Hi, my name is Victor Viberg. I’m studying
biomedical engineering at Linköping University, currently I’m working on my
master thesis in the ISB-group at IMT.
The goal of my project is to create a
model that can explain the metabolic fluxes of a cancer cell and how it differs
from a regular healthy cell. Hopefully this new insight will help in developing
more effective treatments for cancer. The model is based on isotropic labeling
of metabolites, and it is the first time this type of data is available for a
whole human cell. My work will build on the previous work of Nicolas Sundqvist.
This autumn, we welcome another new student in our group: Thea Sandqvist
Hi!
My name is Thea and
I’m here in the ISB Group to do a project in systems biology for my 6th semester in Medicine.
My project is about insulin- and
glucose metabolism in rodents switching between chow- and high fatty based-diets. The project is based on a multi-level-multi-scale model
conducted by former ISB Group-member Niclas Berqqvist. My experimental data
comes from Karin G. Stenkula and her research group in Lund.
Besides spending time at the office I enjoy an occational pain-au-chocolat (or two or five).
This Wednesday I nailed my thesis outside the C2 lecture hall at campus Valla. It was a peaceful, quiet and beautiful ceremony.
Tomorrow, Friday the 13th, I will nail a second copy at IMT, with a bit more pomp and circumstance.
Welcome to “spika-fika” at 14.45 at IMT, campus HU if you want to join for some cake.
You can find my thesis online:
https://doi.org/10.3384/diss.diva-141614
