Tim writes:
TWiN,
I recently saw a show reporting infant facial recognition of multi racial and even monkey faces in early life (3 to 6 months) that is lost by the time they turn 9 months. Could this homeostatic model suggest a developmental fluctuation in IL-33 in the fusiform gyrus of these infants? I’m thinking about function here more than memory… like Erin’s point on different aspects of memory (ie salience, valence…) in this case facial recognition.
I’m wondering if language learning might also be affected by this pruning – marked for and then executed by microglia in other regions of the brain.
Does this model suggest possible models of schizophrenia and or autism that are pruning related but both developmentally emergent? Eric Kandel was very explicit in his most recent book (The Disordered Mind: What Unusual Brains Tell Us About Ourselves, New York: Farrar, Straus and Giroux, ISBN 9780374287863) that a spine resplendent or deficient model is correct for autism and schizophrenia (respectively – low prune == autism while over prune == schizophrenia.) Could IL-33 treatment be a homeostatic developmental intervention for youth in these patients. This is very exciting if so… even if far off or far out for that matter. It’s not all about senescence or Alzheimer.
This SARs pandemic has given me new respect for immunology. This science is as complex as any neuroscience. In fact, I’m beginning to blur the neural and immune systems all together with this paper. Systems can be unhelpful especially in neuroscience (thinking of the misnomer of the limbic and reptilian brain models of brain function and development.)
All these proteins and molecules precede multicellular life (I think all are found in unicellular life at some point) yet multicellular life is using and reusing them again and again in different ways even in fairly proximate places.
Seth Grant was recently on BrainScience.Com with Ginger Campbell. He has opened my brain to the synaptome. The synapse is really where the fun is it seems. I’m wondering if there are differences in the synapses themselves here. It seems like this work is mostly about spine development and glial interaction. I wonder if the synapses themselves are expressing different proteins with respect to the pruning. The astrocytes wrap these synapses tightly I think – If I understand the physiology.
I wasn’t able to access the paper you reviewed but did find this earlier work with similar authors and the same lab. It might be worthwhile to post links to the labs or earlier works if you can’t review open access work for those who are CoVid bound. I will make a trip to the library to see if I can contrast the recent paper with this one below. It seems very similar.
Astrocyte-derived interleukin-33 promotes microglial synapse engulfment and neural circuit development
Science 16 Mar 2018:
Vol. 359, Issue 6381, pp. 1269-1273
DOI: 10.1126/science.aal3589
I noticed that the editors of Cell wrote a preview to the paper Jason presented. I have had much luck reading those to gain perspective but I can’t access that either … doh! I really didn’t get their take from the summary – can you comment on what they said?
Great show. Can you share the figures when you talk about them? I think that is fair use. It would certainly help. Stephanie did that on Immune last week and it helped a ton.
Best,
Tim
Portland, Oregon
PS Someone wrote (I forget who -Kandel or Giulio Tononi or … IDK) that there are as many types of cells in the brain as there are cells in the brain. I think that is true. But in particular there are more types of Glia than two right? Aren’t Oligodendrocytes glial cells. It really surprises me that glial cells have been ignored – having centrioles makes them potentially cancerous. I would think that would focus more attention on them – perhaps not by neuroscientists as much as oncologists but still.
That is changing.
One last thing… I think Chronic Traumatic Encephalopathy has an ECM clearing component (or more likely lack of clearing.) When the blood brain barrier is broken there it makes for a hyper dendritic activity. This paper makes me think about inflammation and concussion recovery in a different way. What is going on in brains. I want to know.
I really appreciate your sharing your time here. I listen and think about these things (mostly in error…) Your judgement and skepticism is inspiring. Keep it coming. Ori, Andres, Erin… awesome comments and insight here.