autoreceptor

noun

au·​to·​re·​cep·​tor ˌȯ-tō-ri-ˈsep-tər 

: a receptor present on the surface of a nerve cell that responds to a neurotransmitter released from the same nerve cell it is located on

When an autoreceptor becomes bound by neurotransmitter molecules in the synapse, the receptors signal the cell to reduce its firing rate and thus its release of the transmitter.

—Charles B. Nemeroff, Scientific American