Ionotropic glutamate receptor (By similarity). Activation by glutamate requires additional verification (PubMed:31474366). L-glutamate acts as an excitatory neurotransmitter at many synapses in the central nervous system. Binding of the excitatory neurotransmitter L-glutamate induces a conformation change, leading to the opening of the cation channel, and thereby converts the chemical signal to an electrical impulse. The receptor then desensitizes rapidly and enters a transient inactive state, characterized by the presence of bound agonist (By similarity). Independent of its ionotropic glutamate receptor activity, acts as a thermoreceptor in the ASER neuron where it triggers a calcium response to activate cold avoidance behavior in response to temperatures below 19 degrees Celsius (PubMed:31474366). Possibly functions as a metabotropic cold receptor and acts upstream of the G(o) G protein goa-1 in the ASER neuron (PubMed:31474366). Also functions in cold sensing in the intestine (PubMed:31474366). Activated by low temperature of 18 degrees Celsius in ASER neuron. Expressed in the intestine and in the ASER neuron (PubMed:31474366). Also expressed in the thermosensitive RIA interneuron (PubMed:11222641). During embryogenesis, expressed just before hatching at low levels. Abolishes signal transduction during cold signaling in intestine and ASER neuron. Belongs to the glutamate-gated ion channel (TC 1.A.10.1) family.