Introducing the brain: neurons change to form memories (Introduction)

by David Turell , Saturday, March 14, 2020, 01:29 (1713 days ago) @ David Turell

It shuttles genetic code within the neuron by altering synapses and transporting mRNA

https://medicalxpress.com/news/2020-03-brain-cells-infrastructure-memories.html

"Now scientists at the Centre for Genomic Regulation (CRG) in Barcelona have found that a type of kinesin called KIF3A/B can transport mRNAs, using another protein called adenomatous polyposis coli (APC) as an adaptor that binds both the kinesin and the mRNA-cargo. The proteins transport at least two types of mRNA which code for tubulin and actin, two types of proteins that neurons use to build their cellular skeleton. This is essential to shape the cell so that it can form new connections with other neurons.

"The findings are of interest because mRNAs play a key role in the storage and formation of memories. Previous studies show that mRNAs coding for the protein beta-actin continuously travel along synapses, the junction between two neurons. When synapses repeatedly receive a signal, the mRNA is used to make beta-actin proteins, which are important for reinforcing synapses and strengthening the attachment between two neurons. Repeatedly stimulating a synapse continuously reinforces the junction, which is thought to be how memories form.

"'Spanish neuroscientist Santiago Ramon y Cajal first proposed that our brains store memories by strengthening neuronal synapses, changing shape so that brain cells would firmly grasp one another and conduct signals more efficiently," says Sebastian Maurer, researcher at the Centre for Genomic Regulation and lead author of the study. "More than a century later we are describing one essential mechanism likely underlying his theories, showing just how ahead of his time he was."

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"The researchers found that mRNAs and their adaptor APC switch on the kinesin's ignition, activating the protein. Transported mRNAs were found to have a special localization signal that control the efficiency by which different mRNAs are loaded onto the kinesin. Even slight alterations to this signal affected the mRNA's journey to its target destination, showing the sophisticated mechanisms brain cells develop to control the logistics of thousands of different messages. When not carrying cargo, the kinesins shifted to energy saving mode to save fuel until their next job."

Comment: Once again a very refined system of molecular changes to manage the system of memory formation. Which raises the next issue: when you try to remember a given pint, how does the brain go about finding it? Nothing about our brain is all that simple, when digging into the biochemistry of thought and memory. Our brain is obviously a miraculous outcome of evolution. Evolution was not unguided but designed.