Writer: Sophie Rogers
Over the last 200 years, UCL has been home to an incredible five Nobel Prize winners for neuroscience-related discoveries. Here’s a closer look at some of their historic work.
Dale & Loewi (1936)
Almost a century ago, nerve impulses were thought to be purely electrical: a theory propagated (no pun intended) by Sir John Eccles. Electrical impulses, called ‘action potentials’, do transmit along neurons. However, thanks to the work of Sir Henry Dale and Professor Otto Loewi, we now know that these impulses cause the release of chemicals called ‘neurotransmitters’, which can cross the gap between neurons to generate another action potential on the other side.
This is fundamental to modern neuroscience – but it took decades of research to be accepted, and some fantastically macabre dream-inspired experiments on frog hearts. Yes, really. By electrically stimulating one of the major nerves to the heart, the vagus nerve, Professor Loewi showed that a mystery substance was released, which he named ‘vagusstoff’. Transfer of this fluid to a different frog heart slowed its spontaneous beating. ‘Vagusstoff’ was later identified as acetylcholine, a neurotransmitter which can slow heart rate and lower blood pressure.
Meanwhile, in his research across UCL and Cambridge, Sir Henry Dale succeeded in isolating acetylcholine from a fungus called ‘ergot of rye’, which commonly infects rye and other cereal crops. Through collaboration, the two confirmed that not only can acetylcholine act on the human nervous system, but it is produced by our own bodies too.
These findings were controversial: it took decades for the ‘soup versus spark’ debates (chemical versus electrical transmission) to be resolved into our hybrid model. However, Dale & Loewi were ultimately awarded the Nobel Prize for revealing the chemical side of neural communication.
Huxley (1963)
The question remained: how do our neurons actually produce electrical signals?
Today, studying neurons is meticulous and painstaking work. In the 1960s, studying neuronal impulses in humans or most animals would have been almost impossible. To get around this, Professor Andrew Huxley and colleagues turned to the giant neurons of the longfin inshore squid. These giant neurons can reach up to 1.5mm in diameter: roughly 100 times larger than our own.
Using a ‘voltage clamp’, the scientists were able to record action potentials inside the giant neurons. Imagine a neuron like a leaky hose containing water. A voltage clamp involves a ‘feedback circuit’ which holds the neuron at a set water pressure (voltage), to measure any changes in the speed of water moving out of holes in the neuronal membrane (current).
Despite the interruption of their research due to the Second World War, Huxley and colleagues would eventually discover that action potentials are the result of charged particles called ions moving in and out of the neuron. In fact, the very same ions that make up table salt – sodium and potassium – drive the electrical language of the brain.
Katz & von Euler (1970)
Sir Bernard Katz and Ulf von Euler were awarded the 1970 Nobel Prize alongside Julius Axelrod for discovering how neurons release neurotransmitters.
Through painstaking experiments on the frog neuromuscular junction (the point where a neuron meets the muscle), Katz measured tiny concentrations of neurotransmitters released by the neuron when stimulating muscle contraction. He found that a familiar neurotransmitter, acetylcholine, is released in specific or ‘quantal’ amounts. Rather than a continuous stream of individual molecules being released, this suggests that neurotransmitters are released from neurons in discrete ‘packets’.
Von Euler discovered the identity of these ‘packets’. Through his work on noradrenaline, he observed compartments called vesicles, which look like tiny bubbles inside neuronal endings. A single vesicle can fuse with the membrane of the neuron to release its neurotransmitter cargo.
O’Keefe (2014)
Professor John O’Keefe has worked at UCL since 1967, and was awarded the 2014 Nobel Prize for his discovery of ‘place cells’ in the brain.
By recording electrical signals from individual neurons in the rat hippocampus, O’Keefe and colleagues discovered that specific neurons fired only when the rat was in a specific location in its cage. Different neurons fire at different locations, effectively forming a detailed internal map of the rat’s environment. O’Keefe termed this ‘cognitive spatial mapping’: an incredible example of how the brain makes sense of our world.
This work laid the foundation for subsequent discoveries, including ‘boundary vector cells’, which help to anchor place cells by tracking the location of spatial boundaries like walls or doors.
O’Keefe continues to teach and research at UCL, with some of his recent work exploring how dementia can affect place cells.
Hinton (2024)
Two years ago, Professor Geoffrey Hinton was awarded the 2024 Nobel Prize in Physics alongside Professor Hopfield. As the founder of the Gatsby Computational Neuroscience Unit situated at UCL, Hinton is known as the ‘Godfather of AI’.
Inspired by real brain structures, his research combined neuroscience and machine learning to build artificial neuronal networks. This led to the creation of the ‘Boltzmann machine’, a system that can learn to find patterns in data autonomously. Hinton’s work underpins much of the ‘deep learning’ that AI models like ChatGPT perform, with wide-ranging effects in modern society.
Looking to the future
UCL’s neuroscience legacy is evident across campus, from the Andrew Huxley building beside the Student Centre to the Bernard Katz building on Malet Place. Inside these buildings, pioneering research continues to drive discoveries that reshape our understanding of the brain – and the future of medicine and technology.
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