Postsynaptic

Part of speech: adjective

Definitions

1. relating to the neuron or cell membrane that receives chemical signals transmitted across a synaptic gap
2. describing the component of a neural junction that responds to neurotransmitters released from the adjacent neuron
3. referring to the part of a nerve junction that engages with neurotransmitters sent from the preceding neuron

Etymology: "Postsynaptic" is a modern scientific term built from the prefix "post-" combined with "synaptic," both components rooted in classical languages but assembled into this compound word only in the twentieth century as neuroscience developed the vocabulary to describe the fine structure of nerve cells. The prefix "post-" comes from Latin and means "after" or "behind." It entered English directly from Latin, where it functioned as both a preposition and prefix denoting sequence or position. This element has been productive in English for centuries, appearing in words like "postwar," "postpone," and "posterior." The root "synaptic" derives from "synapse," which was itself coined in the late nineteenth century. The neuroanatomist Charles Sherrington introduced "synapse" in 1897, deriving it from the Greek elements "syn-" meaning "together" and "haptein" meaning "to fasten" or "to join." The Greek "haptein" is related to the root found in "haptic," concerning touch or tactile sensation. Sherrington needed a term to describe the point of contact between nerve cells, and the Greek-derived "synapse" fit the purpose perfectly, suggesting the joining or connection of neural elements. "Synaptic" is the adjectival form, adding the standard "-ic" suffix (from Latin "-icus") to "synapse" to create an adjective describing things relating to or occurring at synapses. Once "synaptic" was established in neuroscientific vocabulary, "postsynaptic" followed logically: it describes structures, potentials, or processes that occur on the receiving side of a synapse—that is, on the membrane of the nerve cell that receives the signal. The term emerged in the mid-twentieth century as electron microscopy and electrophysiology allowed scientists to distinguish the presynaptic (sending) side from the postsynaptic (receiving) side of neural connections.