Enables extracellularly glutamate-gated chloride channel activity. Involved in neurotransmitter loading into synaptic vesicle. Acts upstream of or within several processes, including chemical synaptic transmission; long-term memory; and sequestering of neurotransmitter. Located in several cellular components, including cerebellar mossy fiber; excitatory synapse; and synaptic vesicle membrane. Is expressed in several structures, including brain; retina layer; and spinal cord dorsal horn. Orthologous to human SLC17A7 (solute carrier family 17 member 7). [provided by Alliance of Genome Resources, Apr 2022]