Talk to Bender the first time (before he's Bender):
"Hello..."
"What's wrong?"
"What made you so sick?"
"Brain enlargement..."
"But if you aren't dumb..."
"Maybe taking the brain enlargement..."
"Isn't there some doctor in town..."
"Maybe I can help..."
"Where can I find this doctor?"
"See you later."

Doc Moore:
"Hello!"
"I'm MapEd"
"I'm a Linarian"
"Yes, I had to fight..."
"Doctor, how can I keep..."
"Can you fix me up?"
"What do you mean, self-inflicted?"
"What can you tell me about Bender?"
"Doc, I took some of those brain..."

At this point, when I return to Bender the conversation starts off as, "You 
took too many strength pills..." automatically from me (unprompted) and his 
reply being "Nah. The strength pills were fine," blahblahblah.