Crew to attack around nerve-centres (7)
I believe the answer is:
ganglia
'nerve-centres' is the definition.
I can't judge whether this definition defines the answer.
'crew to attack' is the wordplay.
'crew' becomes 'gang' (synonyms).
'to attack' becomes 'lia' (I am not sure about this - if you are sure you should believe this answer much more).
'gang'+'lia'='GANGLIA'
'around' is the link.
Can you help me to learn more?
(Other definitions for ganglia that I've seen before include "Cellular networks" , "Cystic tumours" , "I nag gal, having group of nerve cells" , "Structures in the body" , "Nerve cell structures" .)