Untitled Document
Not a member yet? Register for full benefits!

Username
Password
 How to Erase a Memory – And Restore It

This story is from the category The Brain
Printer Friendly Version
Email to a Friend (currently Down)

 

 

Date posted: 06/06/2014

Researchers at the University of California, San Diego School of Medicine have erased and reactivated memories in rats, profoundly altering the animals’ reaction to past events.

The study, published in the June 1 advanced online issue of the journal Nature, is the first to show the ability to selectively remove a memory and predictably reactivate it by stimulating nerves in the brain at frequencies that are known to weaken and strengthen the connections between nerve cells, called synapses.

“We can form a memory, erase that memory and we can reactivate it, at will, by applying a stimulus that selectively strengthens or weakens synaptic connections,” said Roberto Malinow, MD, PhD, professor of neurosciences and senior author of the study.

Scientists optically stimulated a group of nerves in a rat's brain that had been genetically modified to make them sensitive to light, and simultaneously delivered an electrical shock to the animal's foot. The rats soon learned to associate the optical nerve stimulation with pain and displayed fear behaviors when these nerves were stimulated.

Analyses showed chemical changes within the optically stimulated nerve synapses, indicative of synaptic strengthening.

In the next stage of the experiment, the research team demonstrated the ability to weaken this circuitry by stimulating the same nerves with a memory-erasing, low-frequency train of optical pulses. These rats subsequently no longer responded to the original nerve stimulation with fear, suggesting the pain-association memory had been erased.

In what may be the study's most startlingly discovery, scientists found they could re-activate the lost memory by re-stimulating the same nerves with a memory-forming, high-frequency train of optical pulses. These re-conditioned rats once again responded to the original stimulation with fear, even though they had not had their feet re-shocked.

“We can cause an animal to have fear and then not have fear and then to have fear again by stimulating the nerves at frequencies that strengthen or weaken the synapses,” said Sadegh Nabavi, a postdoctoral researcher in the Malinow lab and the study’s lead author.

See the full Story via external site: www.newswise.com



Most recent stories in this category (The Brain):

04/02/2017: HKU scientists utilise innovative neuroimaging approach to unravel complex brain networks

26/01/2017: Personality linked to 'differences in brain structure'

12/01/2017: Donkey Kong used to Help Guide New Approaches in Neuroscience

10/12/2016: Doctors use deep-brain ultrasound therapy to treat tremors

17/02/2015: Hearing experts break sound barrier for children born without hearing nerve

17/02/2015: Smoking thins vital part of brain

05/02/2015: Intracranial Stimulation Proved Efficient in the Recovery of Learning and Memory in Rats

05/02/2015: Repeated head blows linked to smaller brain volume and slower processing speeds