backbone vs ganglion

backbone

noun
  • Any fundamental support, structure, or infrastructure. 

  • Courage, fortitude, or strength. 

  • The series of vertebrae, separated by disks, that encloses and protects the spinal cord, and runs down the middle of the back in vertebrate animals. 

ganglion

noun
  • A centre of intellectual or industrial force, activity, etc. 

  • An encapsulated collection of nerve cell bodies, typically linked by synapses, and often forming a swelling on a nerve fiber. 

  • Any of certain masses of gray matter in the central nervous system, as the basal ganglia. 

  • A benign cystic tumour on a tendon sheath or joint capsule. 

How often have the words backbone and ganglion occurred in a corpus of books? (source: Google Ngram Viewer )