Our brain’s ability to absorb new information relies on its remarkable talent for neural self-reinvention. When we practice something novel, millions of tiny contacts between nerve cells subtly adjust their strength, using multiple mechanisms to store knowledge. This process is known as synaptic plasticity.
However, researchers have long wondered how the brain decides which synapses to retune and which to leave alone. A new study from the University of California San Diego has shed light on this mystery, revealing that each synapse can follow distinct learning rules simultaneously.
Using advanced brain-imaging technology, including two-photon microscopy, scientists observed the brains of mice as they learned a new motor skill. The team found that separate compartments within the same neuron could have different learning rules, contradicting conventional wisdom that neurons obey a single plasticity rule throughout their structure.
This discovery has significant implications for understanding how the brain solves the “credit assignment problem” – determining which connections to reinforce and which to clear away noise. By segregating information streams and applying custom rule sets depending on location, neurons can run multiple internal scoreboards at once, rather than relying on a global scoreboard.
The study’s findings suggest that future AI architectures could benefit from compartment-specific learning rules, potentially leading to more efficient or flexible machines. The discovery also offers new avenues for treating neurological and psychiatric disorders, such as addiction and post-traumatic stress disorder (PTSD), by targeting specific compartments with tailored treatments.
Overall, this research reveals a more complex and nuanced understanding of how the brain learns and adapts, pushing neuroscience closer to deciphering the full score of the brain’s symphony of adaptation.
Source: https://www.earth.com/news/how-the-brain-learns-study-reveals-an-unexpected-twist