Reliability of Synaptic Transmission in Cerebral Cortex Revealed by Research

Researchers from Leipzig University's Carl Ludwig Institute have uncovered significant findings regarding synaptic signal transmission in the human brain. Their study, published on July 4, 2025, in the journal *Science*, reveals that synapses in the cerebral cortex transmit signals with greater reliability compared to those in the rear regions of the brain, even under low calcium ion concentrations. This discovery has implications for both neuroscience and the development of artificial neural networks.

The human brain, comprising approximately 100 billion interconnected nerve cells, processes sensory perceptions through the rapid communication of signals at synapses—contact points between neurons. The study indicates that the properties of the sensor protein synaptotagmin 1, present in the cerebral cortex, allow for effective signal transmission at lower calcium concentrations. In contrast, synaptotagmin 2, found in the rear brain regions, requires higher calcium levels for similar functionality.

Professor Hartmut Schmidt, who led the research team, emphasized the significance of these findings: "Transmission in the cerebral cortex is much more reliable than in other brain regions." The research focused on the primary somatosensory cortex, an area integral to processing sensory information from the body before it is relayed to other cortical regions.

The study employed advanced methodologies, including the patch-clamp technique to measure electrical signals from connected neurons, and a novel method called 'axon walking' to identify active synapses along axons. These insights not only enhance the understanding of healthy brain function but also pave the way for potential therapeutic strategies for neurological disorders.

Moreover, the findings could influence artificial intelligence development, specifically in creating neural networks that mimic human brain processes. The study notes that understanding the mechanisms behind reliable synaptic transmission can inform both biological and computational models of neural activity.

As the research progresses, follow-up studies aim to explore further variations in synaptic transmission across different cerebral cortex regions. These investigations will build on the current model developed by the researchers, which is accessible for use by other scientific teams.

In summary, the research conducted at Leipzig University highlights the critical role of calcium sensitivity in synaptic transmission within the cerebral cortex. This breakthrough enhances our understanding of brain functionality and opens new avenues for technological advancements in neural network applications, signaling a pivotal moment in both neuroscience and computational technology.