Human brain organoids kept maturing for seven years; heat left Morpho wings a duller blue
A Harvard-led team reported in Nature that human brain organoids kept changing for seven years in the dish. Morpho helenor pupae raised at projected heat took longer to emerge, died more often, and left a duller blue.
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Organoids kept changing for seven years in the dish
A Harvard-led team reported in Nature that peppercorn-sized clumps of human brain cells grown from stem cells survived and kept changing for seven years, far past the previous limit of a little under two years. Genetic clocks inside the cells aged at roughly the pace of a developing human brain. Paola Arlotta's group describes organoids that go on maturing over years instead of settling into a fixed state, and says past development is engraved at the cellular level, wording the researchers separate from memory or consciousness.[1]
When cells one year old were mixed with cells two weeks old, the older cells pulled the younger ones forward, yielding neurons that ordinarily take four months to appear. The limits are structural: organoids receive no sensory input and have no body, and researchers broadly agree they cannot support consciousness or higher-order brain function. The organoids used in the work were destroyed afterwards.[1]
Projected heat left Morpho wings a duller blue
Researchers at the Smithsonian Tropical Research Institute raised Morpho helenor pupae at average tropical temperatures, at temperate-zone temperatures, and at the hot temperatures climate projections give for their habitat. The hot group took longer to develop, died more often, and emerged with iridescence dim enough for bird predators and other Morpho to register. The blue of a Morpho wing comes from the spacing of nanostructures on the scales. Under heat that spacing shrinks, each plate thins with it, and neighbouring scales overlap less, which is the mechanism the team offers for the loss of brightness. The paper, in PNAS Nexus, works with a projected temperature applied in the laboratory rather than a warming measured in the forest, and it does not report how many pupae were used, so this experiment does not settle the size of the effect in wild populations.[2]
