Soon there may be a real solution for those times when you’re trying to rack your brain to recall that lost piece. In search of lost memories, it’s easy to feel like you’re getting too old or your short-term memory is a bit of a bust.
Mice With Amnesia
Massachusetts Institute of Technology (MIT) — In a test on these furry victims of amnesia, mice were able to bring back their lost memories. As these mice had amnesia, it was not so much recovering lost memories as it was a reactivation of memories that had previously been blocked. Part of this testing involved optogenetics, a process of applying light to control our light-sensitive neurons.
The studies conclusions suggest lost memories sort of just sit around waiting to be discovered again. This is the case in the mice at least. This is good news for victims of amnesia because it suggests their memories could return through the process of activating brain cells with light.
Is Retrograde Amnesia an Issue of Storage or Retrieval of Memory?
Memory retrieval has been elusive of desired conclusiveness. Researchers at MIT’s Department of of Biology answered some hot topics in neuroscience and retrograde amnesia with this research. Retrograde amnesia follows traumatic injury (i.e. motorvehicle accidents), stress, or diseases (i. –e. Alzheimer’s). Retrograde amnesia occurs after specific brain cells have been damaged. In a event like this, it might be impossible for a following memory to be stored–or else it is blocked from recall, unable to be retrieved.
When it comes to amnesia, neuroscientists have debated whether it is a storage issue or a retrieval issue. MIT’s Department of of Biology found amnesia to be problem of retrieval.
In the process of recalling lost memories, what happens amongst the neurons in the brain’s network? The groups of neurons activated during this process could possibly be reactivated in future instances via a trigger of sorts. It could be the sight of something or the smell of something. In this study, it was a blue light that activated these neuron groups.
The MIT researchers used a technology called optogenetics to trigger the neuron groups that would retrieve memories. Via optogenetics, proteins are clinically added to the the neurons in order to allow them to be activated with light. The team hoped to acquire evidence to show that this group of neurons really exist in the brain–and in the hippocampus, in particular. They would be the first to really demonstrate this.
Engram Cells Recall Lost Memories After Optogenetic Light Activation
The neuron groups that express a memory after optogenetic light activation are called engram cells. This group of cells underwent an increased synaptic strength–in other words, the strength of the synapses connecting them got stronger.
When engram synapses strengthen, the brain is at an advantage because it will now be able to recall or access specific memories it is in search of. Moreover, the stronger connectivity pathways between these engram cells actually allows a more effective storage of memory information. The mice in the study were tested against this.
A compound called anisomycin was administered to the amnesiac mice right after they formed a new memory. The anisomycin is meant to block protein synthesis within the mice’s neurons, meaning that the synapses would not be allowed to strengthen. In the next day’s test, the mice were unable to recall the new memory despite any triggers.
While the same engram cells are there, without protein synthesis and synapse strengthening, the memory could not be kept and found. On the other hand, when researchers reactivated the protein synthesis and used optogentic tools as triggers, the mice were able to retrieve the memories.
