"sentient" is fine
The etymological, technical meaning of "sentient" is "experiencing sensation". Inasmuch as this puddle of neurons apparently responds to changes in its environment, the term is fine.
It's primarily the less rigorous sort of SF which has used "sentient" as a synonym for "sapient", a rather different attribute.
99% of discussions of sentience are irrelevant and misguided. It's not the interesting question.
Biting the hand that feeds IT
