Brain comprises of a star-shaped cells called the astrocytes, which aid in the formation of long-lasting memoriesas studied by a group of researchers at the Salk Institute for Biological Studies.
The new study confirms that these star-shaped cells play a more vital role in addition to the supportive function in the brain. The findings were published in the journal Glia.
The research opens the way to successfully treat the disorders in which long-term memory is affected, including the commontraumatic brain injury or dementia.
A senior author and head of Salk’s Computational Neurobiology Laboratory, Professor Terrence Sejnowski said; “This is an indication that these cells are doing a lot more than just helping neurons maintain their activity,” he elaborated; “It suggests that they’re actually playing an important role in how information is transmitted and stored in the brain.”
For the release of neurotransmitters and for making communication possible throughout the brain, the speedy electrical signals of neurons play a leading role.
However, astrocytes produce signals of calcium and release substances known as gliotransmitters which may be chemically similar to neurotransmitters. It was traditionallybelieved that astrocytes have supportive effect on the more active neurons, these star-shaped cells aid in the nutrient transportation, removing debris and helps the neurons in staying rooted at their place.
The recent study suggested that astrocytes may perform other vital functions in the brain by releasing gliotransmitters but further research can resolve this mystery.
The researchers disclosed that inhibiting the release of gliotransmitters decreases gamma oscillation, a type of electrical rhythm known for its cognitive skills in the astrocytes.
Investigating the effect of IP3R2 receptor on living beings
The research involved trials on mice having dysfunctional astrocytes for testing of learning and memory skills. These findings were conducted by Sejnowski, Salk postdoctoral researcher António Pinto-Duarte and their colleagues in 2014.
For the first time researchers from the team of Sejnowski carried study on the longer-term memory of mice models with defected astrocytes. The study involved the use of genetically engineered animals without the type 2 inositol 1,4,5-trisphosphate receptors (IP3R2). These
IP3R2 receptors aid astrocytes in communication by releasing calcium.
Mice models were trialed with three different types of learning and memory skills and examined for their association with novel objects and determining the exit in a maze.
The researchers observed that the genetically engineered mice have the same learning ability as those of normal mice. Within 24-48 hours observation, the mice models had developed the capability to retain the data thus finding their maze, for instance. The conclusions were in favor of the research findings previously done.
A lead author of the study, António Pinto-Duarte said;”After a few-weeks delay, normal mice actually performed better than they did right after training, because their brain had gone through a process of memory consolidation,” he explained; “The mice lacking the IP3R2 receptor performed much worse.”
The research evidently shows the lack of astrocytes defects memory consolidation or remote memory. Memory consolidation plays essential role in several processes thus affecting the neurons in absence of astrocytes.
The findings show the involvement of astrocytes in the long-term depression of the adjoining neurons.
On the findings, Sejnowskireported; “The mechanism of long-term depression of neurons is not as well studied or understood,” He further explained; “And this tells us we should be looking at how astrocytes are connected to the weakening of these neural connections.”
The researchers are aiming to put efforts into better understanding the mechanism behind the pathways by which these star-shaped cells interact with the long-term depression of neuronal communication and memory skills.
Sejnowskisaid; “The long-term payout here is that if we better understand these pathways, we may be able to develop ways to manipulate memory consolidation with drugs,”
With more research being conducted on the subject the time might not be far where cognitive skills can be improved through drug intake. Moreover, further research might also enable the pharmaceuticals to develop drugs that could stop if not reverse damage to the neurons.