kalim

The ability to store and recover information gives an organism a clear advantage when searching for food or avoiding harmful environments, and has been traditionally linked to organisms that have a nervous system. Our new study challenges this view by uncovering the surprising abilities of a highly dynamic, single-celled organism to store and retrieve information about its environment.
Read more:
Encoding memory in tube diameter hierarchy of living flow network.
Mirna Kramar & Karen Alim,
Proc. Natl. Acad. Sci. U.S.A. 118 (10) e2007815118 (2021).
(Press English) , (Press German) .

Within the newly acquired ERC Starting Grant “FlowMem” we aim to identify the physical principles of how flow networks can retain memories.

Fluid flows through tubular networks are crucial for life as they are the dominant means of substance and signal transport. In living networks – across organisms as disparate as animals and fungi, alterations of flows drive dynamic adaptation of tube diameters which in turn alters transport performance. In effect, local transient stimuli that affect flows are memorized as long-lived alterations to tube diameters across the network. We aim to identify the physical principles behind fluid flows driving dynamic memory storage in network morphology. We will thereby uncover how to control network morphology and performance by applied flow-altering stimuli, which promises significant advances in important challenges of the future: treatment of vascular diseases and tumour development, encoding complex behaviour in soft robotics and self-optimizing porous media.
The dynamic nature of flows and networks’ complex morphologies requires a combined experimental and theoretical approach to address: What are the physical mechanisms of how flows in living tubular networks can encode and store information about stimuli? How do memories impact network performance? As experimental model system we choose the slime mould Physarum polycephalum. It is ideally suited as a starting point, as it reduces the problem in its complexity to just a tubular network. This model allows us to follow with unprecedented level of detail how stimuli transiently perturb network-wide flows – flows that subsequently drive long-term changes in network morphology. Theoretical models will verify mechanisms and allow investigation of impact on network function. Identified principles of dynamic memory formation will be applied to study consequences of mini-stroke stimuli and possible treatment in brain microvasculature and to design self-optimizing porous media. We will develop general principles advancing physics and biology with far-reaching implications in medicine and engineering.

To join us on the project apply for a PhD or Post-doc position.

Karen was awarded an ERC Starting Grant:

Fluid flows through tubular networks like our bloodstream are vital building blocks of life – from simple slime molds to mammals including humans. They not only transport substances and signals but can also dynamically adapt their network architecture to new requirements. These kinds of changes are often memorized in the network for over long periods of time.

In the “FlowMem” project, Prof. Karen Alim aims to identify the physical principles behind the dynamic memory of such changes in network architectures and how they can be controlled. Knowledge of these physical mechanisms provides the basis for new approaches to topics ranging from the treatment of vascular diseases and tumor development to the development of self-optimizing porous materials in fuel cells.

TUM Press Release. EuroTech Universities Press Release. State of Bavaria Press Release. ERC Press Release.

Since January 2018 the Deutsche Physikalische Gesellschaft highlights each week one woman in physics who works in Germany or one German woman in physics who works abroad. This week it is Karen. https://www.dpg-physik.de/vereinigungen/fachuebergreifend/ak/akc/publikationen/physikerin-der-woche

P.M. Wissen the TV science magazine visited us in the lab to learn about Physarum here goes the show. (German only)

Er wirkt wie ein Wesen von einem anderen Stern. Der Schleimpilz „Physarum Polycephalum“ beschäftigt Forscher auf der ganzen Welt. Obwohl er nur aus einer einzigen Zelle besteht, kann er Informationen verarbeiten, effiziente Wege berechnen und scheinbar intelligent handeln.

Hier ist der Link zur Mediathek:

"Blob" – wie schlau sind Einzeller?

The slime mold Physarum polycephalum can add another achievement to its long list of remarkable properties. It is already known to find the shortest way through a maze or to follow a balanced diet, without having a central nervous system. Now we show in experiments that it can also spontaneously adjust its pumping efficiency as soon as its environmental conditions change. Thanks to the clever interaction of two superimposed pumping modes, it doesn’t even need more energy, but can still achieve a considerable increase in performance.

Read the full publication here
Living system adapts harmonics of peristaltic wave for cost-efficient optimization of pumping performance.
Felix K. Bäuerle, Stefan Karpitschka & Karen Alim,
Phys. Rev. Lett. 124,098102 (2020).

or go to the press release
(PDF), (Press English) , (Press German) .

The cell tissue of animals and plants is traversed by a complex vascular network, the blood vessels. The vascular network supplies cells in a tissue with nutrients. Animals can dilate individual capillaries to distribute nutrients differently in the vascular network. How do the capillaries have to be dilated to transport more nutrients to a specific area of the cell tissue? Does the change in nutrient availability for a cell strongly depend on the position of the cell in the tissue? Do vascular networks have a specific structure that allows them to precisely control nutrient supply to cells when only certain areas of cell tissue require more nutrients? To find out more read the article:

Robust increase in supply by vessel dilation in globally coupled microvasculature.
Felix Meigel, Peter Cha, Michael P. Brenner & Karen Alim,
Phys. Rev. Lett. 123, 228103 (2019). (PDF)
or browse the Physics Synopsis , Physics World Research Synopsis, or our press statement in English or German .

Felix graduated with his PhD thesis On mass transport in Physarum polycephalum. Congratulations Dr. Bäuerle!

Jason graduated with his PhD thesis on Morphogenesis control by mechanical stress: Mechanism behind efficient plant growth. Congratulations Dr. Khadka!

Congratulations to Felix J Meigel on the EPL Poster Award of the Association of Biological Physics of the German Physical Society at the spring conference in Regensburg.