Do prions aggregate in response to electrical stimulation and does this play a role in long-term memory?

Prions are multi-stable proteins that can assume at least two stable conformations: a normal one that is detergent-soluble and is protease-sensitive, and a pathogenic one that is protease-resistant and that forms detergent-insoluble fibrillar aggregates. The fibrillar aggregates have been implicated in various neurodegenerative disorders. The normal biological function of prions is not known, yet the high conservation of the sequences of prions among distantly related animals strongly suggests a common and important function. There is now increasing evidence that prions, which are abundant in nervous tissue, may in fact be involved in memory retention. We propose that electrical activity at the synapse induces the surrounding prion molecules to aggregate. The aggregates serve to hold together the synaptic connection between neurons which are interacting at the instant the sensory stimulus is received. The set of neurons connected in this manner then form the neuronal circuit which is associated with the particular stimulus. We propose that the stronger the electrical activity, the greater will be the aggregations. Long-lasting memory will result from traumatic, or exciting, experiences. Further, the aggregations will be maintained, or reinforced, by repeated stimulation of the same set of neurons. Memory loss will occur when those aggregates dissolve.