In the first study of its kind, researchers found that neurons in a specific brain region play a key role in rapidly forming memories about every day events, a finding that may result in a better understanding of memory loss and new methods to fight it in Alzheimer's and other neurological diseases. The study was published in the journal Neuron.
Specifically, the study examined neurons in the medial temporal lobe associated with episodic memory, the brain's ability to consciously recall experienced events and situations like running into an old school friend at the opera. Episodic memory logs these unique experiences and relies on the very rapid formation of new associations in the brain.
The study involved 14 patients with severe epilepsy who were hospitalized and implanted with electrodes in their brains to identify the seizure focus for possible surgical intervention. The patients were shown about 100 pictures of celebrities, animals and places, and the research team analyzed the encoding activity of the individual neurons in the brain as the images registered.
After a single exposure to the composite images, the patients learned the associations between each person and place, such as Clint Eastwood placed in front of the Leaning Tower of Pisa. Medial temporal lobe neurons that selectively responded to Clint Eastwood but not the Tower of Pisa in the first phase of the experiment abruptly began firing to this famous landmark once the patient learned the association. Conversely, neurons that were originally activated by the Tower of Pisa but not by the picture of Eastwood began to respond strongly to the actor as soon as learning occurred. A large proportion of visually responsive neurons in the medial temporal lobe expanded their selectivity to encode these specific associations within a few trials.
Understanding the underpinnings of episodic memory formation is a central problem in neuroscience and may be of important clinical significance because this type of memory is affected in patients suffering from Alzheimer's and other neurological diseases.
The researchers are now working to develop both software and hardware for a neuro-prosthetic device that may restore episodic memory function in neurological patients.
Based on material originally posted by University of California - Los Angeles Health Sciences and Cell Press.