A 60-year argument in neuroscience has been resolved. A team at the Technical University of Munich (TUM) tracked the flow of visual information from one neuron to the next in the intact brain and found that it matches the core predictions of the model David Hubel and Torsten Wiesel proposed in the 1960s, work that earned them the 1981 Nobel Prize but whose details remained contested. The results appear in Science.
The group, led by Prof. Arthur Konnerth with Dr. Yang Chen and PhD student Marinus Kloos at TUM's Institute of Neuroscience and the Munich Cluster for Systems Neurology (SyNergy), built a high-resolution imaging approach capable of measuring the activity of individual synapses in a living brain. They applied it in mice to the pathway that carries signals from the thalamus, the brain's deep relay station, to the primary visual cortex, the first cortical area where basic features such as edges, contrast, and orientation are sorted out.
What makes the finding notable is less the confirmation itself than the fact that it was finally possible to observe directly. The researchers note that Hubel and Wiesel's principles still underpin modern neuroscience and even the design of artificial neural networks, and that biological systems continue to drive technological innovation. Being able to watch synaptic signaling unfold in an intact brain, rather than infer it, gives researchers a much sharper tool for studying how circuits normally pass information along.
The work was done in mice and covers one specific relay in one early stage of vision, so it settles a foundational question rather than describing the whole of perception. Its wider significance may lie in the method: synapses are where communication between neurons succeeds or fails, and techniques that make that communication visible in the living brain open the door to studying it in far more detail.