Rhythm of memory.

MedicalXpress dances to the beat that makes memories in our brains:

UCLA neuro-physicists have found there is an optimal brain “rhythm,” or frequency, for changing synaptic strength. And further, like stations on a radio dial, each synapse is tuned to a different optimal frequency for learning.

The findings, which provide a grand-unified theory of the mechanisms that underlie learning in the brain, may lead to possible new therapies for treating learning disabilities.

When, for example, a synapse was stimulated with just 10 spikes at a frequency of 30 spikes per second, it induced a far greater increase in strength than stimulating that synapse with 10 spikes at 100 times per second.

“The expectation, based on previous studies, was that if you drove the synapse at a higher frequency, the effect on synaptic strengthening, or learning, would be at least as good as, if not better than, the naturally occurring lower frequency,” [Mayank R. Mehta, associate professor in UCLA’s departments of neurology, neurobiology, physics and astronomy,] said. “To our surprise, we found that beyond the optimal frequency, synaptic strengthening actually declined as the frequencies got higher.”

The researchers found that not only does each synapse have a preferred frequency for achieving optimal learning, but for the best effect, the frequency needs to be perfectly rhythmic — timed at exact intervals. Even at the optimal frequency, if the rhythm was thrown off, synaptic learning was substantially diminished.