interneuron (n.) Look up interneuron at Dictionary.com
1939, from neuron + first element from internuncial (adj.) "communicating between different parts of the body," from Latin internuncius "a messenger, mediator," from inter- "between" (see inter-) + nuntius "messenger," from PIE root *neu- "to shout" (cognates: Greek neuo "to nod, beckon," Old Irish noid "make known").