In a landmark stride for neuroscience, scientists have uncovered a novel signaling mechanism within the human brain
Proposing an enhanced level of neural processing power than previously acknowledged, a collaborative effort from research teams in Germany and Greece led to the identification of a new type of ‘graded’ communication emitted by individual neurons found in the cerebral cortex’s external layers. The pivotal study conducted in the year 2020 illuminated that these neurons utilize both sodium and calcium ions to generate electrical impulses, creating a type of voltage wave not observed until now, termed as calcium-mediated dendritic action potentials, or dCaAPs.
Electrical messaging system of the brain
When it comes to the electrical messaging system of the brain, our brains are frequently likened to computers due to their intricate computational capabilities, but the parallel isn’t exact. Both systems operate using electrical charges; computers achieve this via electron movement through transistors, whereas brains depend on the opening and closing of ion channels, exchanging particles like sodium, chloride, and potassium to create an action potential. These neuronal signals are conveyed chemically across dendrites, the branching ends of neurons.
Role of dendrites
“Dendrites play a pivotal role in delineating a neuron’s computational capacity,” highlighted neuroscientist Matthew Larkum of Humboldt University. These signals, vital for neural interaction, serve as the nervous system’s regulatory signals and are indispensable for coherent brain functions.
Discovery of dCaAPs
Within the densely concentrated neuron branches of the brain’s cerebral cortex layers two and three, which are associated with sophisticated functions such as sensation, cognition, and motor control, researchers gathered tissue from patients with epilepsy and scrutinized them using a technique known as somatodendritic patch clamping. This method brought to light the dCaAPs.
Implications of the discovery
Recalling the breakthrough, Larkum expressed the astonishment experienced upon visualizing the dendritic action potentials. Subsequent research on brain tumor tissues affirmed these signals were not exclusive to epileptic conditions. What caught the team off-guard was the neurons’ ability to conduct complex logical operations like standard AND, OR, and even the more nuanced ‘exclusive’ OR (XOR), indicating an elevated level of neuronal computation. This finding carries monumental importance for enhancing our comprehension of the human brain and poses potential breakthroughs in technology aiming to replicate the brain’s formidable computing prowess. Nonetheless, the extent to which this discovery impacts our grasp of advanced cerebral functions will unfold through forthcoming research.
The research findings were initially featured in the journal Science, with an earlier summary of the work circulated in January 2020.
