Just look into the light: not quite, but researchers at the UC Davis Center for Neuroscience and Department of Psychology have used light to erase specific memories in mice, and proved a basic theory of how different parts of the brain work together to retrieve episodic memories.
Optogenetics, pioneered by Karl Diesseroth at Stanford University, is a new technique for manipulating and studying nerve cells using light. The techniques of optogenetics are rapidly becoming the standard method for investigating brain function.
Kazumasa Tanaka, Brian Wiltgen and colleagues at UC Davis applied the technique to test a long-standing idea about memory retrieval. For about 40 years, Wiltgen said, neuroscientists have theorized that retrieving episodic memories — memories about specific places and events — involves coordinated activity between the cerebral cortex and the hippocampus, a small structure deep in the brain.
“The theory is that learning involves processing in the cortex, and the hippocampus reproduces this pattern of activity during retrieval, allowing you to re-experience the event,” Wiltgen said. If the hippocampus is damaged, patients can lose decades of memories.
But this model has been difficult to test directly, until the arrival of optogenetics.
Wiltgen and Tanaka used mice genetically modified so that when nerve cells are activated, they both fluoresce green and express a protein that allows the cells to be switched off by light. They were therefore able both to follow exactly which nerve cells in the cortex and hippocampus were activated in learning and memory retrieval, and switch them off with light directed through a fiber-optic cable.
They trained the mice by placing them in a cage where they got a mild electric shock. Normally, mice placed in a new environment will nose around and explore. But when placed in a cage where they have previously received a shock, they freeze in place in a “fear response.”
Tanaka and Wiltgen first showed that they could label the cells involved in learning and demonstrate that they were reactivated during memory recall. Then they were able to switch off the specific nerve cells in the hippocampus, and show that the mice lost their memories of the unpleasant event. They were also able to show that turning off other cells in the hippocampus did not affect retrieval of that memory, and to follow fibers from the hippocampus to specific cells in the cortex.
The Latest on: Optogenetics
[google_news title=”” keyword=”Optogenetics” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
via Google News
The Latest on: Optogenetics
- Beyond Human Perception: Study Unlocks Secrets Of Consciousnesson April 28, 2024 at 4:31 am
The study introduces the phenomenon of neon color spreading, an optical illusion observed in humans, and explores its effects on mice for the first time.
- Scientists engineer 'mini colons' - sparking revolution in colorectal cancer researchon April 26, 2024 at 11:00 am
Groundbreaking 'mini colons' developed by scientists from Roche Institute of Human Biology and EPFL University have sparked a revolution in colorectal cancer research. Induced to develop tumors using ...
- Illusion demystifies the way vision works: Experiments imply brightness perception occurs deeper in brain than thoughton April 26, 2024 at 8:13 am
For the first time, research shows that a certain kind of visual illusion, neon color spreading, works on mice. The study is also the first to combine the use of two investigative techniques called ...
- Lab-made miniorgans take scientists a step closer to curing canceron April 25, 2024 at 8:34 am
In the fight to cure cancer, scientists need better models. And they might just get them — human-derived organoids — thanks to light.
- Mapping the Neural Circuit of Social Avoidanceon April 25, 2024 at 7:51 am
Moving forward, Lin plans to continue studying this circuit to uncover other neuronal populations and brain regions that may contribute to social avoidance learning. She also wants to examine this ...
- Lab-Grown Mini-Colons Accurately Mimic Colorectal Tumor Developmenton April 24, 2024 at 5:00 pm
The researchers were able to turn inducible oncogenic genes on using “optogenetics”. This cutting-edge technique uses light to control biological processes such as gene expression. By integrating a ...
- Slog AM: First Seattle Police Shooting This Year, Supreme Court Hears Idaho Abortion Case, Senate Passes TikTok Banon April 24, 2024 at 9:23 am
Now to Ashley for a brief interlude… The first police shooting of the year: The King County Medical Examiner’s Office has released the name of the suspect Seattle police killed last week in a sting ...
- Mini-colons advance colorectal cancer researchon April 24, 2024 at 8:00 am
In a breakthrough for cancer research, scientists at EPFL have created lab-grown mini-colons that can accurately mimic the development of colorectal tumors, offering a powerful new tool for studying ...
- Wednesday briefing: Ukraine aid; TikTok ban; David Pecker at Trump’s trial; Supreme Court abortion case; campus protests; and moreon April 24, 2024 at 5:36 am
The Supreme Court will hear arguments today about emergency room abortions. College protests over the Israel-Gaza war are continuing to spread.
- MIT Technology Reviewon April 23, 2024 at 2:00 pm
Polina Anikeeva, PhD ’09, followed up her ultrathin brain probes with tools to study the gut-brain connection—and now leads an MIT research center investigating neural pathways throughout the body.
via Bing News