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Dopaminergic neurons establish a distinctive axonal arbor with a majority of non‐synaptic terminals
Author(s) -
Ducrot Charles,
Bourque MarieJosée,
Delmas Constantin V. L.,
Racine AnneSophie,
Guadarrama Bello Dainelys,
DelignatLavaud Benoît,
Domenic Lycas Matthew,
Fallon Aurélie,
MichaudTardif Charlotte,
Burke Nanni Samuel,
Herborg Freja,
Gether Ulrik,
Nanci Antonio,
Takahashi Hideto,
Parent Martin,
Trudeau LouisEric
Publication year - 2021
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.202100201rr
Subject(s) - dopaminergic , neuroscience , neuroligin , glutamatergic , postsynaptic potential , synaptic pharmacology , axon , active zone , neurotransmission , dopamine , biology , gabaergic , synapse , synaptotagmin 1 , neurexin , neuron , excitatory postsynaptic potential , synaptic vesicle , synaptic fatigue , inhibitory postsynaptic potential , glutamate receptor , biochemistry , receptor , vesicle , genetics , membrane
Chemical neurotransmission typically occurs through synapses. Previous ultrastructural examinations of monoamine neuron axon terminals often failed to identify a pre‐ and postsynaptic coupling, leading to the concept of “volume” transmission. Whether this results from intrinsic properties of these neurons remains undefined. We find that dopaminergic neurons in vitro establish a distinctive axonal arbor compared to glutamatergic or GABAergic neurons in both size and propensity of terminals to avoid direct contact with target neurons. While most dopaminergic varicosities are active and contain exocytosis proteins like synaptotagmin 1, only ~20% of these are synaptic. The active zone protein bassoon was found to be enriched in dopaminergic terminals that are in proximity to a target cell. Finally, we found that the proteins neurexin‐1α SS4− and neuroligin‐1 A+B play a critical role in the formation of synapses by dopamine (DA) neurons. Our findings suggest that DA neurons are endowed with a distinctive developmental connectivity program.