This week Bryce Vissel from the Sydney Garvan Institute of Medial Research was on ABC radio discussing the results of the study that had been published in the 29th September edition of PLoS One. Researchers from Australia and the States have identified a new way that the brain can create memories and store information. The implication of this is that this new pathway may prove useful to provide new and alternative ways of treatments where there has been brain injury or death, such as with stroke and Alzheimer’s disease.
The way our brain works to store memories involves the hippocampus where an essential mechanism called the NMDA receptor is involved. When the NMDA receptor is activated, calcium is allowed to enter the brain cell, which then triggers further molecular reactions resulting in our brain being able to process, store and recall information. Our understanding over the last twenty or thirty years has been that learning could not take place without these receptors. The scientists were looking to replicate the mechanism artificially and coincidentally uncovered an existing second system that the brain already has in place. In this second system a different receptor called AMPA does the job of encoding memory, but appears only to be activated when the information received is similar to something we have previously learnt. This is called second learning.
The questions now being raised from this finding is to work out what causes this second mechanism to operate. Then it may be possible to look for ways to get it to take over the role of the NMDA mechanism if that isn’t working because of disease or injury. It might then be used to protect us against conditions such as Alzheimer’s (where the ability to form new memories is lost), because it could be that stimulation of this alternative pathway would then help us to keep participating in memories. The other potential implication of this finding is that having this second means of learning could have really important effects on how we approach teaching in the classroom in the future as well.
Ref: A Role for Calcium Permeable AMPA Receptors in Synaptic Plasticity and Learning. Wiltgen BJ, Royle GA, Gray EE, Abdipranoto A, Thangthaeng N, et al. 2010 A Role for Calcium-Permeable AMPA Receptors in Synaptic Plasticity and Learning. PLoS ONE 5(9): e12818. doi:10.1371/journal.pone.0012818