Article Correctness Is Author's Responsibility: Small Set of Genes May Provide Unique Barcode for Different Types of Brain Cells August 19, 2020 Author: Neuroscience News Category: brain researchThe article below may contain offensive and/or incorrect content. The adult nervous system of a C. elegans worm contains 302 neurons, which can be divided into 118 types. Seventy homeobox genes are involved in characterizing the neuron types.