Animated, showing nerve, effects reform (12)
I believe the answer is:
effervescent
'animated' is the definition.
(thesaurus)
'nerve effects reform' is the wordplay.
'reform' is an anagram indicator.
'nerve'+'effects'='nerveeffects'
'nerveeffects' is an anagram of 'EFFERVESCENT'.
'showing' acts as a link.
(Other definitions for effervescent that I've seen before include "Sparkling" , "Fizzy" , "Bubbly" .)