I have to agree that my metaphor was heavy handed (heavy footed?), but I distinctly remember how this was not a debate, but a dogma. People who suggested brain cells could regenerate were ridiculed. Everyone "knew" they couldn't (everyone "scientific" that is). The reason I remember it so clearly is that it was an early example in my experience of seeing dogma in what other people called science. The idea that brain cells would have some special non-regenerating status struck me instinctively as preposterous. It was a great example of how people turn "We have not observed X" into "X never happens", and from there it's a tiny step to "People who believe in X are nutcases".

On a parenthetical note, I haven't yet got around to reading Kuhn but the basic idea there strikes me as profoundly correct. When the majority consciousness isn't ready to acknowledge a phenomenon, it simply doesn't "exist". Evidence can change received opinion, but only if a shift in majority consciousness occurs first. (That's how I understand Kuhn's paradigms anyway.)