Learning and memory in the brain has long been believed to be mediated by changes in the strengths of synaptic connections between neurons and a phenomenon termed synaptic plasticity. Most excitatory synapses in the brain are hosted on small membrane structures called dendritic spines, and plasticity of these synapses is dependent on calcium concentration changes within the dendritic spine.
In the last decade, it has become clear that spines are highly dynamic structures that appear and disappear, and can shrink and enlarge on rapid timescales. It is also clear that this spine structural plasticity is intimately linked to synaptic plasticity. Small spines host weak synapses, and large spines host strong synapses. Because spine size is one factor which determines synaptic calcium concentration, it is likely that spine structural plasticity influences the rules of synaptic plasticity. I am theoretically studying the consequences of this observation, and find that different spine-size to synaptic-strength relationships can lead to qualitative differences in long-term synaptic strength dynamics and information storage.
Related Publications and Presentations
- Cian ODonnell, Matthew Nolan, and Mark C W Van Rossum, “Dendritic spines can stabilize synaptic weights”, COSYNE, 2010.
- Cian ODonnell, Matthew Nolan, and Mark C W Van Rossum, “Dendritic spines as devices for synaptic metaplasticity”, Dendrites Gordon Research Conference, 2009.
- Cian ODonnell, Matthew Nolan, and Mark C W Van Rossum, “Dendritic spine dynamics regulate the long-term stability of synaptic plasticity”, Journal of Neuroscience, 2011, 31, 16142.