Yes, when your stomach gurgles or you experience pain it is an indication that something is wrong in the system. If all is well you don't know they are there at all. No Dave, you're seeing this from the wrong perspective. Interoception is a subconscious brain function. You become consciously aware only when something goes wrong, like a palpitating heart. That's a serious control problem and you cannot think it right. You have to trust your subconscious control mechanism to regulate the pace of your heart. When you are resting you don't feel your heart. You can hear it, you can feel your pulse, but you cannot just feel your heart sitting in its little sack. Perhaps my ignorance makes mt too optimistic, but from what I have gleaned so far, I find no fundamental conflict in any of the proposed functions of microtubules. I admit my ignorance of fine detail, but then I am comforted by the number and authority of the scientists who are pursuing what has been called "very promising". And why not? Should we stop research? On what grounds? Microtubules do not function as they have been observed to function?