It’s a common expression to say your brain is full, but now synaptic changes shows remembering and forgetting can be based on the brain pushing out info.
According to Scripps Research, for the first time it has been shown that the physiological mechanism by which a memory is formed and then subsequently forgotten is indeed a phenomenon that occurs. The research, which was conducted on fruit flies, looked at the synaptic changes that occur during learning, remembering and forgetting. The investigators found that a single dopamine neuron can drive both the remembering and forgetting process.
The art of remembering and forgetting
Jacob Berry, PhD, a postdoctoral associate in the Department of Neuroscience on Scripps Research’s Florida campus, USA, says: “We believe this system is set up to remove memories that are unimportant and not necessarily supposed to last a long time,” says
“I find it elegant that all of this is done with the same neuron. Our paper highlights exactly how this is achieved.”
The researchers studied the memory of flies, whereby the insects were conditioned to associate a particular odour with an electric shock. Once they had been conditioned, scientists observed that they subsequently avoid that particular odour, which confirms that the memory had been made. By monitoring the activity of neurons in the brain before and after the conditioning process, scientists could get an inside look at the physiological underpinnings of memory formation.
In the current study, the investigators discovered that when a behavioural memory is degraded, the cellular changes made during the learning process are reversed by the same dopamine neuron that helped form the changes in the first place, therefore contributing to the remembering and forgetting aspect of the brain.
“Whenever you learn something new, you’re simultaneously forming a new memory while potentially interfering with or erasing old ones,” Berry says. “It’s a very important balancing act that prevents you from becoming overloaded.”
Ron Davis, PhD, a professor and chair of the Department of Neuroscience at Scripps Research explains further: “Only recently have neuroscientists grasped the importance of active forgetting and begun to unravel the processes that causes the brain to forget.”
Time to look at the synaptic changes in the human brain
Although the research was conducted on fruit flies, the investigators expect that the findings will apply to higher organisms, including humans.
“Evolution worked out a lot of important processes like this pretty early on,” Berry says, “so there’s a lot of relevance to studying these synaptic pathways in simpler organisms.”
This study led by Berry not only provides new insights into the brain mechanisms for remembering and forgetting but also offers a wonderful example of how much we learn about brain function from laboratory animals like the fruit fly, Drosophila.
Understanding the processes of both remembering and forgetting, and potentially how to manipulate them, has a number of implications for humans. Such a discovery is beneficial for conditions like drug addiction or post-traumatic stress disorder, it may be beneficial to develop approaches that can boost active forgetting. Improving memory retention, on the other hand, could help to treat dementia and other forms of memory loss.