Innovative Brain-Wide Mapping Reveals a Single Memory Is Stored Across Many Connected Brain Regions:
A new study from 's Picower Institute for Learning and Memory provides the most extensive and rigorous evidence yet that the mammalian brain retains a single memory across a broadly distributed, functionally integrated complex spanning many brain regions, rather than in just one or a few spots.
Memory research pioneer Richard Semon had predicted such a "unified engram complex" more than a century ago, but achieving the new study's confirmation of his hypothesis required the application of multiple newly developed technologies. The researchers found and ranked dozens of previously unknown memory-related areas in the study, demonstrating that memory recall becomes more behaviorally powerful when multiple memory-storing regions are reactivated rather than just one.
"When talking about memory storage we all usually talk about the hippocampus or the cortex," said co-lead and co-corresponding author Dheeraj Roy. He began the research while a graduate student in the RIKEN-MIT Laboratory for Neural Circuit Genetics at The Picower Institute led by senior author Susumu Tonegawa, Picower Professor in the Departments of Biology and Brain and Cognitive Sciences. "This study reflects the most comprehensive description of memory encoding cells, or memory 'engrams,' distributed across the brain, not just in the well-known memory regions. It basically provides the first rank-ordered list for high-probability engram regions. This list should lead to many future studies, which we are excited about, both in our labs and by other groups."
[...] The team was able to map regions participating in an engram complex by conducting an unbiased analysis of more than 247 brain regions in mice who were taken from their home cage to another cage where they felt a small but memorable electrical zap. In one group of mice their neurons were engineered to become fluorescent when they expressed a gene required for memory encoding. In another group, cells activated by naturally recalling the zap memory (e.g. when the mice returned to the scene of the zap) were fluorescently labeled instead. Cells that were activated by memory encoding or by recall could therefore readily be seen under a microscope after the brains were preserved and optically cleared using a technology called SHIELD [...]. By using a computer to count fluorescing cells in each sample, the team produced brain-wide maps of regions with apparently significant memory encoding or recall activity.
The maps highlighted many regions expected to participate in memory but also many that were not. To help factor out regions that might have been activated by activity unrelated to the zap memory, the team compared what they saw in zap-encoding or zap-recalling mice to what they saw in the brains of controls who were simply left in their home cage. This allowed them to calculate an "engram index" to rank order 117 brain regions with a significant likelihood of being involved in the memory engram complex. They deepened the analysis by engineering new mice in which neurons involved in both memory encoding and in recall could be doubly labeled, thereby revealing which cells exhibited overlap of those activities.
Journal Reference:
Roy, Dheeraj S., Park, Young-Gyun, Kim, Minyoung E., et al. Brain-wide mapping reveals that engrams for a single memory are distributed across multiple brain regions [open], Nature Communications (DOI: 10.1038/s41467-022-29384-4)
(Score: -1, Troll) by Anonymous Coward on Wednesday April 27 2022, @03:55AM (1 child)
What does "single memory" even mean?
Thought so.
(Score: 0) by Anonymous Coward on Wednesday April 27 2022, @04:09AM
Did you?
(Score: -1, Troll) by Anonymous Coward on Wednesday April 27 2022, @06:47AM
Sure it does!! More than previously thought! And just think of the applications, what will create apps that make tons of money for the creators, and the early investors! I missed out on Apple stock at $1.50 a share, no way I am letting the opportunity of Pico-power pass me by!
Elon
(Score: 3, Interesting) by JoeMerchant on Wednesday April 27 2022, @06:40PM (1 child)
While the focus of so much brain research to-date has been "mapping" which regions do what, the results have been mostly... fuzzy. Things like mapping of sensory and motor neurons to their attachment points work well with the mapping approach, but functional mapping not so much.
The data and theories I have read over the years that make the most sense about memory, decision making and other cognitive aspects of the brain all seem to come back to coherence of repeating patterns - not only are memories encoded across wide areas of the brain, but they are encoded as a pattern of firings, and things like decisions are made by competing patterns "recruiting" wider and wider areas until one pattern becomes dominant and that is either the decision you have made or the memory you are recalling...
This all also fits with the reality: people rarely if ever remember exactly what happened, they recall a mish-mash of their perceptions, prejudices, etc. into a synthesized story that is related to the recalled event rather than a concrete reconstruction. Same for decision making, wafflers, etc.
The brain is not a computer system designed for precision, it's a guidance system designed to survive environmental challenges and procreate, accuracy is entirely optional.
You do the hokey-pokey and you turn yourself about. That's what it's all about.
🌻🌻🌻 [google.com]
(Score: 1, Interesting) by Anonymous Coward on Thursday April 28 2022, @04:50PM
Hey, check this out https://www.biologyexams4u.com/2014/10/what-are-place-cells-and-grid-cells-in_19.html [biologyexams4u.com]
that work won the Nobel Prize for Medicine in 2014.
Some amazing stuff. I have some very clear theories - that the hippocampus /encodes/ but doesn't long term /store/ location data; instead it works as CPU registers, where other connexions are activated in ways which re-establish those location encodings ('load register') before they can be worked with ('indirect deref location, food'), and so on and so on.
I think you'd be interested in the P300 impulse also, eg. https://www.researchgate.net/profile/Redmond-Oconnell/publication/277571226_The_classic_P300_encodes_a_build-to-threshold_decision_variable/links/556d862408aec22683056f07/The-classic-P300-encodes-a-build-to-threshold-decision-variable.pdf [researchgate.net]