Summary: Memory formation requires high frequency ripples in the hippocampus and low frequency ripples in the parietal cortex. However, to make a thumb drive, coordinated high-frequency ripples between the hippocampus and the parietal cortex are needed.
Source: Colombia University
Neuroscientists know that what makes a memory truly stick is reconsolidation, when a new memory is reactivated by the same or similar experiences, stimulating the creation of additional and stronger neural connections.
If researchers can better understand what happens in the brain during reconsolidation, new ways to strengthen memories weakened by dementia or suppress unwanted memories in post-traumatic stress disorder could potentially be created.
Oscillations in the electrical activity of the brain, ie brain waves, are already known to play a role in the creation of new memories. So a team of Columbia neuroscientists led by Jennifer Gelinas, MD, Ph.D., assistant professor of neurology at Columbia University Vagelos College of Physicians and Surgeons, set out to determine how brain oscillations interact to help memories build up. .
To do this, neuroscientists recorded the brain oscillations of rats as they navigated a maze, finding water rewards they remembered and encountering new ones.
The results are published in the journal Proceedings of the National Academy of Sciences.
The recordings revealed that the coordination of brain oscillations between two brain regions (hippocampus and parietal cortex) plays a key role in solidifying long-term memories and differs from the brain oscillations primarily involved in creating initial memories.
To make a thumb drive, a coordinated interaction between high frequency ripples in the hippocampus of the brain and high frequency ripples in the parietal cortex was required, while memory creation required high frequency ripples in the hippocampus. and low frequency oscillations in the cortex.
By simply looking at the brain recordings, the researchers were able to determine whether the rats were learning a new memory or reinforcing an old one.
The results suggest that different mechanisms are at play when memories are consolidated and reconsolidated, which has potential clinical implications.
“Many neurological conditions are characterized by underactive or overactive retention of long-term memories,” says Gelinas. “It is possible that some of these oscillations that we have identified are disturbed under these conditions. A better understanding of these processes could lead to new ways to diagnose and treat these memory problems.
The team is now applying these findings to neuropsychiatric disease models with the aim of identifying new opportunities for improving memory function.
About this memory research news
Author: Press office
Source: Colombia University
Contact: Press Office – Columbia University
Picture: Image is in public domain
Original research: Access closed.
“Hippocampus-cortical coupling differentiates long-term memory processes” by Prawesh Dahal et al. PNAS
Abstract
See also
Hippocampus-cortical coupling differentiates long-term memory processes
The reactivation of long-term memories allows the strengthening, weakening or updating of memory traces depending on the experience.
Although the coupling of hippocampal and cortical activity patterns facilitates initial memory consolidation, it is unclear if and how these patterns are involved in post-reactivation memory processes.
Here, we monitored the hippocampal-cortical network as rats learned and repetitively retrieved spatial and non-spatial memories.
We show that the interactions between hippocampal high-wave undulations (SPW-R), cortical spindles (SPI) and cortical undulations (CXR) are co-modulated in the absence of memory demand but recruited independently in depending on the stage of memory and the type of task.
Memory reconsolidation after recovery is associated with an increased and extended coupling window between hippocampal SPW-Rs and CXRs compared to initial consolidation. Hippocampal and cortical spindle SPW-R interactions are preferentially engaged during memory consolidation.
These results suggest that specific, time-bound models of oscillatory coupling can support the distinct memory processes needed to flexibly manage long-term memories in a dynamic environment.