presynaptic
adjective
pre·syn·ap·tic ˌprē-sə-ˈnap-tik 
: of, occurring in, or being a neuron by which a nerve impulse is conveyed to a synapse
a presynaptic membrane
a presynaptic neuron
presynaptically
ˌprē-sə-ˈnap-ti-k(ə-)lē
adverb 
Example Sentences
Recent Examples on the Web For example, sponge neuroid cells not only express some of the presynaptic machinery of neurons, but also express immune genes. 
Quanta Magazine, 4 Nov. 2021 The findings from this new study seem to bear on that mystery because the researchers found presynaptic gene sets expressed in neuroid cells and postsynaptic genes expressed in choanocytes. Quanta Magazine, 4 Nov. 2021 It had been observed that vesicles containing neurotransmitters routinely hover in clusters near the presynaptic membrane until they are needed. Quanta Magazine, 26 Nov. 2018
Quanta Magazine, 4 Nov. 2021 The findings from this new study seem to bear on that mystery because the researchers found presynaptic gene sets expressed in neuroid cells and postsynaptic genes expressed in choanocytes. Quanta Magazine, 4 Nov. 2021 It had been observed that vesicles containing neurotransmitters routinely hover in clusters near the presynaptic membrane until they are needed. Quanta Magazine, 26 Nov. 2018 Word History
First Known Use
1937, in the meaning defined above
Medical Definition
presynaptic
adjective
pre·syn·ap·tic -sə-ˈnap-tik
: relating to, occurring in, or being part of a neuron by which a nerve impulse is conveyed to a synapse
presynaptic terminals
presynaptic inhibition
a presynaptic membrane