Breaking News: Students Probe Slime Mold Memory During Summer Neuroscience Research

Students probe slime mold memory during summer neuroscience research

Liam Safran ’23 and Jenny Makhoul ’23 worked together to study the memory mechanisms possessed by this unique single-celled organism.

From: Sarah Wojcik
Wednesday, September 7, 2022 9:36 AM



To see it – a thin neon yellow spot in a Petri dish – you’d be forgiven for your lack of confidence in slime mold’s cognitive abilities.

This humble single-celled organism is neither plant, animal, nor fungus (although it has been categorized as such for many years). Slime molds belong to a different biological kingdom: the protists.

This summer, Liam Safran ’23, a neuroscience major on the pre-dental track, and Jenny Makhoul ’23, a biochemistry major, got to know the organisms that have been known to baffle researchers for decades.

“It’s kind of interesting because there’s this thing that you’ve never thought about in your whole life, and now it’s like such a central part of my daily life,” Safran said with a laugh. “Over time, you sort of develop a weird relationship.”


Liam Safran 23 and Jenny Makhoul worked with slime mold and memory during summer research.

Working in the lab of psychology and neuroscience professor Gretchen Gotthard, Makhoul and Safran investigated how slime molds can create memories – and how those can be interrupted – despite the lack of a central nervous system.

Slime mold bodies, consisting of a single cell, can stretch, grow, and move to food sources. They will also avoid obstacles that they detect as harmful. And through experimentation, Safran and Makhoul collected data that seems to show that while slime molds can know if a perceived danger is real, that memory can be disrupted in ways that cause them to forget that information.

The lab partners brought the slime mold to a food source that the organisms found particularly tasty – in this case, oats. To reach the oats, the slime mold had to cross a “bridge” covered in vinegar. They could tell the organisms had become accustomed to the vinegar when they found them crossing the deck as quickly as those slime molds that didn’t have to fight the vinegar.

This result shows that the slime mold had begun to exhibit habituation, a form of non-associative memory. Safran and Makhoul hope to extend the experiment to determine if slime mold can perform more complex associative memory functions that could be disrupted by an amnesic agent.

Part of what was so rewarding about research, Safran said, is that neuroscience professors were so adamant that he tackled a research topic that touched him personally. Safran said he has always been fascinated by memory and is increasingly interested in exploring science that challenges preconceived notions of the separation of mind and body.

Choosing to work with slime mold meant that he and Makhoul had to do a lot of reading and research to prepare the lab for the organisms, but such work increased his sense of belonging to science.



“I really enjoyed learning how to design and execute research at all levels,” said Safran. “You get really intimate with the scientific process. And you gain a lot of discipline from that.

By tackling this particular research topic, Makhoul was entering a different field of study, driven by his passion for understanding memory and problem solving. The result was to dig into a topic of great interest and expand its knowledge base.

“It’s been rewarding to be able to step away from biochemistry a bit and focus on something that I don’t usually know about,” Makhoul said. “I was able to discover another science that fascinates me.”

The data collected on slime mold could have implications for a better understanding of biological memory, Safran said, particularly concepts related to memory storage. Research shows that a brain is not necessary for acquiring and modifying memories, Gotthard explained. Safran and Makhoul’s work has the potential to be the first published study to show that memory reconsolidation is possible in a brainless organism, Gotthard said.

“Research is a difficult undertaking even when researchers are pursuing an established line of work. Starting from scratch, as Jenny and Liam and their former collaborators did, greatly increases the challenge,” Gotthard said. “The perseverance and creativity that Liam and Jenny put into this work has made all the difference in moving this research forward.”


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