Membrane G-protein coupled estrogen receptor that binds to 17-beta-estradiol (E2) with high affinity, leading to rapid and transient activation of numerous intracellular signaling pathways. Plays a role in the embryonic development of sensory and motor neurons. Specifically induces apoptosis and reduces proliferation of brain cells. Involved in maintenance of meiotic arrest in oocytes. {Experimental EvidencePubMed:18420744, Experimental EvidencePubMed:19228597, Experimental EvidencePubMed:23583372}.