GABA as a Neurotransmitter in Gastropod Molluscs

Biol Bull. 2019 Apr;236(2):144-156. doi: 10.1086/701377. Epub 2019 Jan 16.


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.

Keywords: BCI, buccal-cerebral interneuron; CBC, cerebral-buccal connective; CBI, cerebral-buccal interneuron; CNS, central nervous system; CPG, central pattern generator; Cr-Aint, cerebral A interneuron; DA, dopamine; EPSP, excitatory postsynaptic potential; FCAP, feeding circuit activating peptide; GABA, gamma-aminobutyric acid; GABAli, GABA-like immunoreactivity; IPSP, inhibitory postsynaptic potential; PKC, protein kinase C.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Animals
  • Gastropoda / chemistry
  • Gastropoda / physiology*
  • Motor Neurons / chemistry
  • Motor Neurons / physiology
  • Neurons / chemistry
  • Neurons / physiology
  • Neurotransmitter Agents
  • gamma-Aminobutyric Acid / metabolism*
  • gamma-Aminobutyric Acid / physiology


  • Neurotransmitter Agents
  • gamma-Aminobutyric Acid