The Alamo, USA, most of all a vital relay station (8)
'vital relay station' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'the alamo usa most of all a' is the wordplay.
I cannot really understand how this works, but
'usa' could be 'us' (synonyms) and 'us' is present in the answer.
'a' is found in the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for thalamus that I've seen before include "bit of brain" , "a bit of brains" , "Sensory part of brain; a lush mat (anag.)" , "Grey matter at base of brain" .)
'the alamo usa most of all a vital' is the definition.
I can't judge whether this definition defines the answer.
'relay station' is the wordplay.
'relay' becomes 'narrate' (I've seen this before).
'station' becomes 's' (this could be a standard abbreviation which I don't know about).
'narrate'+'s'='NARRATES'
Can you help me to learn more?
(Other definitions for narrates that I've seen before include "Recites, recounts" , "provides an account" , "Tells (a story)" .)