The brain uses unique systems to save recent versus remote worry memories. Previous research studies have suggested that while the initial formation of worry memory involves the hippocampus, it gradually matures with time and ends up being less based on the hippocampus. Much research study now explains how current fear memory is stored, however how the brain combines remote fear memories is not well understood.
The scientists concentrated on the PFC, a part of the cerebral cortex that has been implicated in remote memory debt consolidation in previous studies.
” We found a small group of nerve cells or neurons within the PFC, termed memory nerve cells, were active during the preliminary terrible event and were reactivated during the recall of remote fear memory,” Cho stated. “When we selectively inhibited these memory nerve cells in the PFC, it prevented the mice remembering not current but remote worry memory, recommending the vital role of PFC memory neurons in the recall of remote fear memories.”
In the experiments, the mice got an aversive stimulus in an environment called a context. They found out to associate the aversive stimulus with the context. When exposed to the same context a month later, the mice froze in action, showing they could remember remote worry memories. The scientists revealed that connections (synapses) in between memory neurons in the PFC, termed prefrontal memory circuits, were slowly reinforced with time after fear learning, and such strengthening assisted the PFC completely save remote fear memories.
Next, to snuff out the remote worry memory in the mice, the scientists consistently exposed the mice to the exact same fear-predictive context but without the aversive stimulus. The result was a minimized fear reaction to the context.
” Interestingly, the extinction of remote worry memory weakened the prefrontal memory circuits that were formerly enhanced to store the remote worry memory,” Cho said. “Moreover, other manipulations that blocked the fortifying of the PFC memory circuits likewise prevented the recall of remote fear memory.”
Cho explained that a dysregulation of worry memory consolidation can cause chronic maladaptive fear in PTSD, which impacts about 6% of the population at some point in their lives.
” Considering that PTSD patients experience fear memories formed in the remote past, our study offers an essential insight into establishing healing strategies to reduce persistent fear in PTSD clients,” he said.
Next, Chos team prepares to selectively compromise the prefrontal memory circuits and examine whether this adjustment reduces the recall of remote worry memories.
” We expect the results will contribute to developing a more efficient intervention in PTSD and other fear-related conditions,” Cho said.
Referral: “Neocortical synaptic engrams for remote contextual memories” by Ji-Hye Lee, Woong Bin Kim, Eui Ho Park, and Jun-Hyeong Cho, 23 December 2022, Nature Neuroscience.DOI: 10.1038/ s41593-022-01223-1.
The research study was moneyed by the National Institutes of Mental Health.
The image reveals worry memory nerve cells (red) amongst all prefrontal cortex neurons (blue). Credit: Cho laboratory, UC Riverside
A research study carried out by UC Riverside researchers on mice may pave the way for brand-new ingenious treatments for individuals with PTSD.
A mouse study from the University of California, Riverside, published in Nature Neuroscience, has actually discovered the basic systems that drive the brain to consolidate remote fear memories of terrible events from the past, ranging from a few months to decades earlier.
The study reveals that remote fear memories from the far-off past are completely stored in the connections in between memory nerve cells in the prefrontal cortex (PFC).
” It is the prefrontal memory circuits that are gradually strengthened after terrible occasions and this conditioning plays a vital role in how fear memories grow to stabilized forms in the cerebral cortex for permanent storage,” said Jun-Hyeong Cho, an associate teacher of molecular, cell and systems biology, who led the research study. “Using a similar system, other non-fear remote memories might likewise be completely kept in the PFC.”
The brain utilizes distinct mechanisms to store remote versus recent worry memories. Previous studies have actually recommended that while the initial formation of fear memory involves the hippocampus, it progressively grows with time and becomes less reliant on the hippocampus. Much research study now explains how recent worry memory is stored, but how the brain combines remote worry memories is not well understood.
When exposed to the very same context a month later on, the mice froze in response, suggesting they could remember remote worry memories. The researchers showed that connections (synapses) between memory nerve cells in the PFC, described prefrontal memory circuits, were gradually reinforced with time after worry knowing, and such strengthening helped the PFC completely save remote fear memories.