Spontaneous and multifaceted ATP release from astrocytes at the scale of hundreds of synapses – Wow, shit’s got levels.
Interpreting this, astrocytes can “encourage” information from particular neurons by adjusting the amount of ATP on a synapse by synapse basis (and conversely suppress input by reducing energy).
This granular control is independent of the global “wave” signalling.
Is the idea of astrocytes as an “information switchboard” coherent?
Seems like extracellular Ca2 serves as a “macro” state signal, and nervous systems can organize this discrete calculation according to the needs of these concurrent macro signals.
Think of a single astrocyte managing a few thousand neuronal input streams, when a macro wave comes in for say “fear”, the individual streams are all adjusted by the astrocyte on a granular level. Because only very small adjustments are needed to accommodate the requirements of the global state, this synapse by synapse energy management allows pretty efficient re-calculation of stimuli streams because it doesn’t require gross adjustment of homeostatic balance. That’s kind of cool.
The really cool thing about this finding is that it puts a lot of weight behind the idea that astrocytes at least form a completely “interdepedent” network from neuronal signalling, they aren’t simply reacting to what neurons are doing.
It seems like this is the core of “cognition” isn’t it? The ability to decouple from the pure stimuli and recalculate state independently?
Work like this tends to draw me back to the “autism” model, particularly big/little astrocyte work. Too much control = not enough stimuli response. Too little control = too reactive. Interesting.
Also, this work underlines just how myopic and trendy we are with measuring activity in general, the obsessive focus with Ca2 means that we aren’t seeing anywhere near a complete picture of intercellular mechanics with astrocytes. We are still only seeing a very tiny part of the actual “work” happening and making huge assumptions based on that.