Researchers here at Cool-jams have long known that sleep is important for forming and retaining memories, but how this process really works remains a mystery to most researchers. A study published in March suggests that some kind of electrical activity, involving neurons that fire backwards, play an important role in strengthening our memory.
Neuronal activity typically requires sensory input—like a taste or smell which gets received by neurons’ and then transmitted as an electrochemical message to other cells. This is interesting because the brain is mostly closed off to sensory input during sleep. Instead research seems to suggest that during sleep, neurons are controlled by electrical impulses that pulse through the brain like waves. In 2011 researchers found that these waves of electricity cause neurons in the hippocampus, the main brain area involved with memory, to fire backward during sleep, sending an electrical signal from their axons to their own dendrites rather than to other cells. The new work, published in the Proceedings of the National Academy of Sciences USA, confirmed this unusual behavior and suggested that firing in reverse weakens the dendrites’ ability to receive input from other neurons.