Where is your Memory? (Not a Trick Question)
The human brain is like a computer. It translates, processes, and stores data for later consumption. A hundred years ago, world-renowned scientist Santiago Ramony Cajal predicted that the brain stores information in front of synapses and connections between neurons.
Ever since scientists worldwide have been trying to decipher the complexities of memory formation in the brain. However, memory mapping is challenging to accomplish. Because synapses are micro electric charges that are difficult to detect, they are also tightly packed together.
The synapses are estimated to be 10 million billion times smaller than the smallest object a clinical MRI can scan. In a rat, there are one billion synapses identical to the gray matter that is translucent.
After much experimentation, scientists discovered that every memory synapse changes how the brain cells connect. In the human brain, complex memories are made from a part and not a whole. Certain stimuli ignite memory in the human brain. For example, a smell ignited a memory or a speech.
Most times, memory formation is called consolidation. The hippocampus is the seat of memory in the human brain. However, other memory details are stored in several cortexes scattered around the brain—precisely the prefrontal cortex.
As the name implies, it is the frontal region of the human brain. Exposure to any cue would activate the prefrontal cortex, which would, in turn, activate the hippocampus. It is challenging to study the memory in a brain due to certain limitations.
Priya Rajasethupathy, a neuroscientist at Rockefeller University, and her team formulated a method for continuously recording and mapping several brain activities in multiple brain areas. As the mice encounter various smells and sights, it plays a massive role in their multi-sensory area.
The mice were in ongoing virtual memory consolidation. The researchers trained the mice to detect several rooms, which consisted of different sensory cues. It was either aversive or rewarding. After a few times, acclimatization sets in, and the mice know when to expect different tastes or smells.
They knew when they would be given sugar, water, or any other beverage. When the items were placed, they could easily trace them with their nasal sensors due to memory localization.
At the end of the experiment, it was denoted that the hippocampus is primarily the central region for memory formulation. The peripheral sensory receptors of the organisms were responsible for individual perceptions in memory, and these synapses are transferred to the prefrontal cortex.
Potential Treatment
After the experiment, the results indicate that there could be a potential and long-lasting treatment for Alzheimer's. “This suggests that there’s a dedicated pathway for memory recall separate from memory formation,” says Nakul Yadav, a graduate student and a mentee of Dr. Priya and Conor Liston, a neuroscientist at Weill Cornell Medicine.
The results will be used to determine memory formulation and storage. They will also be treated as separate entities during further research.
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