Central elements in clue's anagram fodder (6)
I believe the answer is:
nuclei
'central elements' is the definition.
(plural of nucleus)
'in clue's anagram fodder' is the wordplay.
'anagram fodder' is an anagram indicator (letters in the clue provide fodder for an anagram).
'in'+'clue'='inclue'
'inclue' anagrammed gives 'NUCLEI'.
(Other definitions for nuclei that I've seen before include "Central pieces" , "hearts" , "Atomic cores" , "Centres of atoms" , "Cores of atoms" .)