New research published this week in the journal *Nature* is challenging decades of neurological understanding regarding how the brain forms and retains long-term memories. Scientists at Rockefeller University have discovered that memory isn’t governed by a single process, but rather a complex sequence of “molecular timers” operating across multiple brain regions, offering potential new avenues for treating memory loss [[2]]. The study, utilizing innovative virtual reality models with mice, identifies specific genes crucial in determining which experiences are remembered and which are forgotten, raising hopes for future therapies targeting conditions like Alzheimer’s disease – which currently affects approximately 6.7 million Americans .
A new study from Rockefeller University published in the journal Nature has revealed a surprisingly complex process by which the brain decides which memories to retain long-term and which to discard. Understanding how memories are prioritized could one day lead to new treatments for memory loss conditions like Alzheimer’s disease.
For years, scientists believed memory formation relied on a single mechanism. However, researchers now suggest memory isn’t governed by a single “switch,” but rather a series of “molecular timers” operating in sequence across multiple brain regions.
The research team, led by Priya Rajasethupathy, developed an innovative behavioral model using virtual reality specifically designed for mice to observe how the brain differentiates between repeated, important experiences and fleeting ones, according to scitechdaily. This system allowed scientists to control the number of times mice were exposed to different experiences and track whether the resulting memories would become solidified or fade away.
The study challenges the long-held belief that the hippocampus works in isolation to store memories. Instead, researchers found the hippocampus acts as an initial point of contact, with the thalamus playing a central role as a “sorting center.” The thalamus determines which memories are worthy of being transferred to the cerebral cortex for long-term storage.
Using CRISPR gene-editing technology, the researchers identified three key genes – Camta1 and Tcf4 in the thalamus, and Ash1l in the anterior cingulate cortex – that control memory persistence. Disrupting these genes demonstrated that each regulates a different stage of memory consolidation, confirming that the process unfolds through a series of timed stages.
“The first molecular timers work quickly to sort initial information, followed by slower timers that strengthen neural connections and make the memory more stable,” Rajasethupathy explained. “If a memory isn’t upgraded through these stages, the brain is primed to forget it.”
Interestingly, the study highlighted that one crucial molecule, Ash1l, belongs to a family of proteins with similar roles in other biological systems, such as the immune system, where they help cells “remember” previous infections. This suggests a fundamental biological principle at play in how the body retains important information.
Rajasethupathy believes that understanding these mechanisms could pave the way for new treatments for memory disorders. “If we can identify alternative brain regions responsible for stabilizing memories, we may be able to bypass damage and allow healthy areas to compensate,” she said.
The research team is now planning to investigate the factors that activate these molecular timers and determine their duration, aiming for a deeper understanding of the brain’s criteria for valuing and retaining each memory. These findings could ultimately lead to strategies for bolstering memory function and mitigating the effects of cognitive decline.
