Meninges are the thin layers of tissue that protect the brain and the spinal cord under the skull.

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Sandwiched between them was a wafer-thin disc of membrane tissue.

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Previous efforts to document neural wiring usually required samples of brain tissue to be sliced into hundreds or thousands of thin sections and then painstakingly reconstructed.

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This, too, is significant because the "scarring" tissue that naturally forms after a heart attack is thin and can get stretched in ways that alter the shape of the heart.

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