[2] They play vital roles in reflexes, neuronal oscillations,[3] and neurogenesis in the adult mammalian brain.

[4] Local interneurons have short axons and form circuits with nearby neurons to analyze small pieces of information.

[7] Investigations into the molecular diversity of neurons is impeded by the inability to isolate cell populations born at different times for gene expression analysis.

In addition to these general functions, interneurons in the insect CNS play a number of specific roles in different parts of the nervous system, and also are either excitatory or inhibitory.

For example, in the olfactory system, interneurons are responsible for integrating information from odorant receptors and sending signals to the mushroom bodies, which are involved in learning and memory.