Brain complexity: memory formation (Introduction)

by David Turell , Friday, April 27, 2018, 18:06 (2185 days ago) @ David Turell

Enlarging synapses is part of the process:

https://www.the-scientist.com/?articles.view/articleNo/52441/title/Learning-Enhances-Sy...

"When making memories, certain neurons form larger, denser connections, according to a study published today (April 26).

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"In the study, Kaang and his team first injected the recombinant DNA into the hippocampus, a key brain area involved in memory formation, of mice. Then, the team used a fear-conditioning experiment to teach the rodents to associate a specific environment with an electric shock.

"When probing the animals’ brains under a microscope, the researchers observed that synapses between engram cells were enhanced. Dendrites, the neuronal projections that synapses form on, between engram cells were denser and larger than those between engram cells and non-engram cells, or between two non-engram cells. In addition, when the team compared mice that had been exposed to weak versus strong electric shocks, they found synaptic connectivity was stronger in mice receiving stronger shocks.

“'What’s very nice is they showed that the difference between the weak and strong memory is not that strong memories recruit more neurons,” says Sadegh Nabavi, a neuroscientist at Aarhus University in Denmark who did not take part in the study. “The number of neurons is similar, [but] the difference is that the synapses have larger sizes, higher density, and bigger diameters.”

"According to Wiltgen, this study “advances previous work by showing that small groups of hippocampal neurons ‘wire together’ during learning to form new memories.” He adds that the new work, along with other studies, “shows that many of our ideas about memory generalize to the real world.”

"Tomás Ryan, a neuroscientist at Trinity College Dublin in Ireland who also didn’t take part in this study, notes that while this is the first experiment that has labeled the specific synaptic inputs from engram and non-engram cells, prior work, including his own, has shown that new synaptic connections form between engram cells, and it’s that process that underlies memory formation."

Comment: The study shows how the brain responds to work of the s/s/c in memory formation. When we remember something, we must be able to find where it is stored in the brain. This shows the interdependence of brain and s/s/c.