Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.

Q: the thalamus is a symmetrical structure in the brains of vertebrates.

A: thalamus
****
Q: the long-beaked echidnas make up one of the two genera (genus zaglossus) of echidna.

A: long-beaked echidna
****
Q: a commode is a special piece of furniture.

A:
commode
****