中间神经元，又称转接神经元（relay neuron），或共同神经元（association neuron）或局部回路神经元（local circuit neuron），是一种多极性神经元，在神经传导路径中连接上行（afferent）及下行（efferent）神经元。如运动神经元（motor neuron），中间神经元的细胞本体（soma）皆位于中枢神经系统（central nervous system，CNS）。

An interneuron (also called relay neuron, association neuron, connector neuron or local circuit neuron) is one of the three classifications of neurons found in the human body. Interneurons create neural circuits, enabling communication between sensory or motor neurons and the central nervous system (CNS). They have been found to function in reflexes, neuronal oscillations, and neurogenesis in the adult mammalian brain. Interneurons can be further broken down into two groups: local interneurons, and relay interneurons. Local interneurons have short axons and form circuits with nearby neurons to analyze small pieces of information. Relay interneurons have long axons and connect circuits of neurons in one region of the brain with those in other regions. The interaction between interneurons allow the brain to perform complex functions such as learning, and decision making.