How does the brain store and recall memories? What molecular mechanisms enable the storage of memory? What underpins the learning process?
If you are curious, come listen to Timothy Bliss who has been awarded the Croonian Lecture, delivered annually at the Royal Society in London.
We now know that the crucial component is the synapse – the junction between two neurons that enables the transmission of an electrical signal from one cell to the next. Timothy Bliss and Terje Lømo worked together in the late 60s on the rabbit hippocampus (important for short-term and long-term memory) and established the phenomenon of long-term potentiation (LTP).
LTP refers to the long-lasting enhancement in signal transmission between two neuronal cells. Persistent activation and enhancement induces chemical changes at a cellular level, which result in the strengthening of the synapse. As such, synapses are reinforced by positive feedback.
This suggests that the brain is plastic – i.e. that it can be moulded. Indeed, our personal experiences shape the growth and loss of synapses: throughout our lifetime, new synapses are formed, strengthened and pruned. These changes in synapses account for the brains plasticity and are enabled by LTP and long-term depression (LTD). LTD refers to negative feedback, the opposite of LTP.
The original theory of plasticity is called “Hebbian plasticity”, named after Donald Hebb who proposed this theory in 1949. It was not until Bliss and Lømo’s work, however, that this became truly apparent.
Thanks to the work of these two men, it is now well acknowledged that LTP underpins memory and learning. I strongly recommend this lecture (its free!), particularly because it is Timothy Bliss himself who will be talking. The lecture will provide an overview of how the brain stores memory, one the most fascinating things that our brains can do!
For more information visit the event page.
Hope to see you there!