Montreal, The enigma of memory has intrigued philosophers and intellectuals for a long time. Plato and Aristotle believed that memory was found only in the realm of the soul and mind, but there was nothing corporeal or physical about it. Memory is closely linked to our sense of self and subjective experiences, but there are physical processes associated with remembering.
The modern analogy likes to compare computer memory to that of the brain, where the activity of brain cells called neurons is compared to the binary codes of magnetic field patterns stored on a hard drive. However, computing devices do not change as a result of doing their work, unlike neurons.
Storing and processing memories uses nanoscopic motor proteins called kinesin that move materials within neurons to build the structural code of memory. These nanoscopic workers “walk” using alternating steps on long molecular tracks to deliver materials. For 20 years, neuroscientists (including me) have used cutting-edge microscopy technology in living animals to observe microscopic structures called dendritic spines that constantly sprout, They transform and recede into the dendrites of neurons.
Dendritic spines are where neurons form contacts with other neurons and create electrical circuits throughout the brain. Dendritic spine plasticity, as this change in the shape of dendrites is known, is more than the random movement of neuronal structures in the brain.
Budding spines to store new memories. In our recently published study, it is discovered that the degree of plasticity of the dendritic column is highly correlated with the memory performance of animals in our laboratory. We taught mice to fear a harmless tone by electrocuting them every time the tone was played; Next, we taught the mice to overcome the same fear by presenting the same tone repeatedly in a harmless situation.
After two days, the degree of fear, indicated by the time the mice were motionless, represents memory performance. The greater the number of dendritic spines that sprouted on the neurons, the shorter the time they remained frozen.
Similarly, the scientists found that motor memory (indicated by how long mice can run on a rotating rod after training) also correlates with the number of budding dendritic spines on neurons. When these newly formed dendritic spines are scratched using sophisticated technology called optogenetics, the mice lose their motor memory and behave as if they have not trained at all.
This evidence strongly affects the way we understand the way memory is stored. Beyond the all-or-nothing activity of an entire neuron, the structural traces of memory are formed by the patterns of microscopic structures called dendritic spines on neurons.
Delivering molecular cargo to the spinesThis discovery posed another challenge: how do neurons know where specifically on their branches to “build” these memory codes? These locations must be specific as they correspond to points of contact with different neurons to form neural circuits relevant to different experiences.
Since most cellular materials are synthesized in the cell body, there must be a transporter that delivers the materials into neurons to achieve precise construction of memory codes.
In our study, we speculate that kinesin was used to deliver molecular materials to “build” dendritic spines. To demonstrate this, we labeled molecular cargoes that kinesin is known to carry with fluorescent markers, so that we could follow the movement of kinesin under the microscope. Using this cutting-edge microscopy technology, we were able to track the movement of kinesin in the brain before and after creating and eliminating fear in mice. We also genetically deleted kinesins from another group of mice to understand whether the function of kinesin was really necessary to form the memory code of the dendritic column. We found that in normal kinesin mice, it took several hours, rather than minutes, for kinesin to move to a specific location on the dendrites, where dendritic spines can sprout. If kinesin was removed from the brain, the labeled molecular cargoes showed reduced movement and, as a result, the number of dendritic spines formed was completely altered and the stability of those formed was significantly hampered.
Without kinesin, mice were unable to learn and form memory properly in our study.
Understanding memoryThis is the first time that the process of formation of the structural code of memory has been visualized, identifying kinesin as the transport for the construction of dendritic spines after a learning experience to build the structural code of memory in the brain alive. This structural memory code can provide an even more complex dimension than the binary encoding of information.
Greater understanding and potential mapping of these large-scale dendritic spine structural codes in the brain could open up new ways to manipulate memory functions in medical conditions. (The conversation) NSA
NSA
The modern analogy likes to compare computer memory to that of the brain, where the activity of brain cells called neurons is compared to the binary codes of magnetic field patterns stored on a hard drive. However, computing devices do not change as a result of doing their work, unlike neurons.
Storing and processing memories uses nanoscopic motor proteins called kinesin that move materials within neurons to build the structural code of memory. These nanoscopic workers “walk” using alternating steps on long molecular tracks to deliver materials. For 20 years, neuroscientists (including me) have used cutting-edge microscopy technology in living animals to observe microscopic structures called dendritic spines that constantly sprout, They transform and recede into the dendrites of neurons.
Dendritic spines are where neurons form contacts with other neurons and create electrical circuits throughout the brain. Dendritic spine plasticity, as this change in the shape of dendrites is known, is more than the random movement of neuronal structures in the brain.
Budding spines to store new memories. In our recently published study, it is discovered that the degree of plasticity of the dendritic column is highly correlated with the memory performance of animals in our laboratory. We taught mice to fear a harmless tone by electrocuting them every time the tone was played; Next, we taught the mice to overcome the same fear by presenting the same tone repeatedly in a harmless situation.
After two days, the degree of fear, indicated by the time the mice were motionless, represents memory performance. The greater the number of dendritic spines that sprouted on the neurons, the shorter the time they remained frozen.
Similarly, the scientists found that motor memory (indicated by how long mice can run on a rotating rod after training) also correlates with the number of budding dendritic spines on neurons. When these newly formed dendritic spines are scratched using sophisticated technology called optogenetics, the mice lose their motor memory and behave as if they have not trained at all.
This evidence strongly affects the way we understand the way memory is stored. Beyond the all-or-nothing activity of an entire neuron, the structural traces of memory are formed by the patterns of microscopic structures called dendritic spines on neurons.
Delivering molecular cargo to the spinesThis discovery posed another challenge: how do neurons know where specifically on their branches to “build” these memory codes? These locations must be specific as they correspond to points of contact with different neurons to form neural circuits relevant to different experiences.
Since most cellular materials are synthesized in the cell body, there must be a transporter that delivers the materials into neurons to achieve precise construction of memory codes.
In our study, we speculate that kinesin was used to deliver molecular materials to “build” dendritic spines. To demonstrate this, we labeled molecular cargoes that kinesin is known to carry with fluorescent markers, so that we could follow the movement of kinesin under the microscope. Using this cutting-edge microscopy technology, we were able to track the movement of kinesin in the brain before and after creating and eliminating fear in mice. We also genetically deleted kinesins from another group of mice to understand whether the function of kinesin was really necessary to form the memory code of the dendritic column. We found that in normal kinesin mice, it took several hours, rather than minutes, for kinesin to move to a specific location on the dendrites, where dendritic spines can sprout. If kinesin was removed from the brain, the labeled molecular cargoes showed reduced movement and, as a result, the number of dendritic spines formed was completely altered and the stability of those formed was significantly hampered.
Without kinesin, mice were unable to learn and form memory properly in our study.
Understanding memoryThis is the first time that the process of formation of the structural code of memory has been visualized, identifying kinesin as the transport for the construction of dendritic spines after a learning experience to build the structural code of memory in the brain alive. This structural memory code can provide an even more complex dimension than the binary encoding of information.
Greater understanding and potential mapping of these large-scale dendritic spine structural codes in the brain could open up new ways to manipulate memory functions in medical conditions. (The conversation) NSA
NSA
