**2.1 Glutamate-gated chloride channels (GluCls)**

Glutamate-gated chloride channels (GluCls) are found only in protostome invertebrate phyla. Their functions include: the control and modulation of locomotion, the regulation of feeding, and the mediation of sensory inputs [29]. This channel is composed of 5 adjacent subunits. Each subunit is a polypeptide chain large extracellular N-terminal domain (for ligand binding) and four transmembrane domains (1–4) (**Figure 3**) [30].
