Open AccessGABA as a Neurotransmitter in Gastropod Molluscs
Author(s) -
Mark W. Miller
Publication year - 2019
Publication title -
the biological bulletin/biological bulletin
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.669
H-Index - 77
eISSN - 1939-8697
pISSN - 0006-3185
DOI - 10.1086/701377
Subject(s) - gabaergic , neurotransmitter , neuroscience , biology , inhibitory postsynaptic potential , excitatory postsynaptic potential , neurotransmitter agents , gamma aminobutyric acid , neurotransmission , central nervous system , receptor , biochemistry
The neurotransmitter gamma-aminobutyric acid (GABA) is widely distributed in the mammalian central nervous system, where it acts as a major mediator of synaptic inhibition. GABA also serves as a neurotransmitter in a range of invertebrate phyla, including arthropods, echinoderms, annelids, nematodes, and platyhelminthes. This article reviews evidence supporting the neurotransmitter role of GABA in gastropod molluscs, with an emphasis on its presence in identified neurons and well-characterized neural circuits. The collective findings indicate that GABAergic signaling participates in the selection and specification of motor programs, as well as the bilateral coordination of motor circuits. While relatively few in number, GABAergic neurons can influence neural circuits via inhibitory, excitatory, and modulatory synaptic actions. GABA's colocalization with peptidergic and classical neurotransmitters can broaden its integrative capacity. The functional properties of GABAergic neurons in simpler gastropod systems may provide insight into the role of this neurotransmitter phenotype in more complex brains.