Neuroscientists have revealed that the spinal cord may make its memories, independently of the brain. This breakthrough discovery has the potential to revolutionize how spinal cord injuries are treated.
Previous studies have revealed that the spinal cord may initiate reflex movements without the brain’s involvement, and it appears to learn and adapt actions based on prior experiences. The mechanism underlying this has been unknown.
“Learning and memory are often attributed as functions of the brain exclusively. Although scientists knew for more than a century that the spinal cord could learn and adapt movements in the absence of brain input, we did not know how the spinal cord learns and memorizes what it has learned,” Aya Takeoka, the author of the study, told Newsweek.
“Gaining insights into the underlying mechanism is essential if we want to understand the foundations of movement automaticity in healthy people and use this knowledge to improve recovery after spinal cord injury,” she added.
How did the neuroscientists reach this conclusion?
To better understand the role of neurons in reflexive learning, the researchers first investigated whether spinal cord cells could adapt to sensory inputs in the absence of brain signals.
When they tried it with a pair of mice, they observed that the spinal cord could learn and remember independently of the brain.
They then attempted to identify the neuronal circuitry that allowed the spinal cord to store memory. They observed that the spinal cord does not require learning or memory cells to recall and learn from its previous experiences.
“The two groups of nerve cells have distinct functions; learning cells are not needed for recalling what the spinal cord had learned, and memory cells were not needed for learning,” researchers derived.
“Not only do these results challenge the prevailing notion that motor learning and memory are solely confined to brain circuits, but we showed that we could manipulate spinal cord motor recall, which has implications for therapies designed to improve recovery after spinal cord damage,” Takeoka added.