Giraffes neurons can be up to 15 feet long. Blue whales are speculated to have neurons up to 100 feet long, though they've never been directly observed (dissected).
They've been catastrophically dissected at least once, which we know due to the detailed field notes made by Paul Linnman, and subsequent citations by Dave Barry.
It's possible some of them were observed, given the likelihood of striking someone's glasses or windshield.
It's possible some of them were observed, given the likelihood of striking someone's glasses or windshield.