messengers IP3 and DAG. The climbing fibers stimulate a large increase in postsynaptic Ca2+ levels when activated. The Ca2+, IP3, and DAG work together in a signal transduction pathway to internalize AMPA receptors and decrease the sensitivity of the postsynaptic cell to glutamate. See also Coincidence circuit Earth Coincidence Control Office Hebbian theory Long-term depression Long-term potentiation Neurobiology Neuroethology Quantum mind Sound localization References Further reading https://web.archive.org/web/20040519194818/http://bbsonline.cup.cam.ac.uk/Preprints/OldArchive/bbs.neur4.crepel.html External links Auditory Localization by ITD Analysis: The Jeffress Model - Online interactive tutorial (Flash) Neuroethology concepts Coincidence