Understanding the brain requites more than neuron connectivity:
> These waves of calcium, rippling across astrocytes, reflect signaling dynamics that modulate neurons.
Neuromodulation is necessary for keeping the brain’s activity level in a functional range, preventing it from either flatlining or erupting in seizures.
For years, neuromodulation was thought to be conducted by neurons themselves. While previous work has implicated astrocytes in some cellular signaling, the latest experiments use “advanced techniques to really pinpoint and satisfy beyond a doubt that astrocytes are having a key role in neuromodulation in the brain.
An excellent Quanta Magazine articles dives into the history and new evidence for the roles of astrocytes and their control over neurons. It has many implications:
"The results suggest that neuron-only brain models, such as connectomes, leave out a crucial layer of regulation."