Summary: A new study finds that repetitive practice not only improves skills, but also induces significant changes in the brain’s memory pathways. The research shows how training mice to recall sequences of odors led to stable memory representations in the secondary motor cortex.
These findings improve understanding of learning and memory and could inform treatments for memory-related disorders. The study used a new microscope to track the neuronal activity of up to 73,000 neurons.
Highlights:
- Solidification of memory: Repetitive practice stabilizes memory patterns in the brain.
- New technique: Researchers imaged 73,000 neurons to observe changes in memory circuits.
- Consequences: Knowledge could help fight memory-related disorders.
Source: UCLA
A new study led by UCLA Health has shown that repetitive practice is not only helpful in improving skills, but also leads to profound changes in the brain’s memory pathways.
The research, published in the journal Nature and co-led by Rockefeller University, sought to understand how the brain’s ability to retain and process information, known as working memory, improves through training.
To test this, researchers tasked mice with identifying and recalling a sequence of odors over a two-week period.
The researchers then tracked the animals’ neuronal activity as they practiced the task using a new custom-made microscope capable of imaging the cellular activity of up to 73,000 neurons simultaneously throughout the cortex.
The study revealed a transformation in working memory circuits located in the secondary motor cortex as the mice repeated the task over time. As the mice learned the task for the first time, the memory representations were unstable.
However, after practicing this task repeatedly, the memory patterns began to solidify or “crystallize,” said corresponding author and UCLA Health neurologist Dr. Peyman Golshani.
“If we imagine that each neuron in the brain emits a different note, the melody that the brain generates as it completes the task changed from day to day, but then became more and more refined and similar as the animals continued to practice the melody task,” Golshani said.
These changes provide insight into why performance becomes more precise and automatic after repetitive practice.
“This idea not only advances our understanding of learning and memory, but also has implications in combating memory-related disorders,” Golshani said.
The work was carried out by Dr. Arash Bellafard, project scientist at UCLA, in close collaboration with Dr. Alipasha Vaziri’s group at Rockefeller University.
About this news from research in memory and neuroscience
Author: Will Houston
Source: UCLA
Contact: Will Houston – UCLA
Picture: Image is credited to Neuroscience News
Original research: Free access.
“Volatile working memory representations crystallize with practice” by Peyman Golshani et al. Nature
Abstract
Volatile working memory representations crystallize with practice
Working memory, the process by which information is maintained and manipulated transiently over a brief period, is essential for most cognitive functions. However, the mechanisms underlying the generation and evolution of neuronal working memory representations at the population level over long periods of time remain unclear.
Here, to identify these mechanisms, we trained head-fixed mice to perform a delayed olfactory association task in which mice made decisions based on the sequential identity of two odors separated by a 5-s delay.
Optogenetic inhibition of secondary motor neurons during late delay and choice epochs strongly impaired mouse performance.
Mesoscopic calcium imaging of large neuronal populations from the secondary motor cortex (M2), retrosplenial cortex (RSA), and primary motor cortex (M1) showed that many late epoch-selective neurons emerged in M2 as the mice learned the task.
Accuracy of late working memory decoding improved significantly in M2, but not in M1 or RSA, as mice became experts.
During the early expert phase, working memory representations during the late delay period drifted across days, while stimulus and choice representations stabilized.
In contrast to single-plane layer 2/3 (L2/3) imaging, simultaneous volumetric calcium imaging of up to 73,307 M2 neurons, which included superficial L5 neurons, also revealed stabilization of representations late effects of working memory with continued practice.
Thus, activities related to delays and choices, essential for working memory performance, drift during learning and only stabilize after several days of expert performance.
News Source : neurosciencenews.com
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