Network homeostasis

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Chapter 4 endnote 5, from How Emotions are Made: The Secret Life of the Brain by Lisa Feldman Barrett.
Some context is:

A [sports] team has a pool of players; at any given moment, some players are in the game and others sit on the bench, ready to jump in when needed. Likewise, an intrinsic network has a pool of available neurons. Each time the network does its job, different groupings of its neurons play (fire) in synchrony to fill all the necessary positions on the team. You might recognize this behavior as degeneracy, because different sets of neurons in the network are producing the same basic function.

Network homeostasis[1][2] is that idea that neurons dynamically adjust their synapses so that they fire within the same dynamic range as each other, and the ensemble continues to work together, even as certain neurons bow out and others join in. The best example of this research has been conducted by the incomparable neuroscientist Eve Marder and her colleagues.[3][4][5] Neurons “self-tune” their intrinsic firing rates dynamically to stay “in sync” with their neighboring neurons, leading to network stability. This is how different realizations of the network produce virtually indistinguishable behavior.[6] This is also how we know that it is best to think about mental functions at the network level, and not at the module or hub level, and that a network is not, itself, a module, but a population of neurons with high levels of degeneracy.

Notes on the Notes

  1. Maffei, Arianna, and Alfredo Fontanini. 2009. "Network homeostasis: a matter of coordination." Current Opinion in Neurobiology 19 (2): 168-173.
  2. Marder, Eve and Jean-Marc Goaillard. 2006. "Variability, compensation, and homeostasis in neuron and network function." Nature Reviews Neuroscience 7 (7): 563-575.
  3. Marder, Eve. 2012. “Neuromodulation of Neuronal Circuits: Back to the Future.” Neuron 76 (1): 1–11.
  4. Marder, Eve, and Adam L. Taylor. 2011. “Multiple Models to Capture the Variability in Biological Neurons and Networks.” Nature Neuroscience 14 (2): 133–138.
  5. Prinz, Astrid A., Dirk Bucher, and Eve Marder. 2004. "Similar network activity from disparate circuit parameters." Nature Neuroscience 7 (12): 1345-1352.
  6. This is similar to the idea, from neuroscientist Olaf Sporns, that a network has one structural motif that constrains its many and variable functional motifs. See Sporns, Olaf, and Rolf Kötter. 2004. "Motifs in brain networks." PLoS Biology 2 (11): e369.