Okay, the user wants me to translate "signaling compounds" into Thai. Let me check if the original content is already in Thai. No, it's in English. So I need to translate it. The correct translation for "signaling compounds" in Thai would be "สารสื่อประสาท". I should make sure there's no explanation, just the translation. Let me confirm the term again to avoid any mistakes. Yep, that's the right term. Alright, ready to output the translation.