Editing Tonotopy (section)

==== Cochlea ====
Tonotopic organization in the cochlea forms throughout pre- and post-natal development through a series of changes that occur in response to auditory stimuli.<ref>{{cite journal | vauthors = Mann ZF, Kelley MW | title = Development of tonotopy in the auditory periphery | journal = Hearing Research | volume = 276 | issue = 1–2 | pages = 2–15 | date = June 2011 | pmid = 21276841 | doi = 10.1016/j.heares.2011.01.011 | s2cid = 38361485 }}</ref> Research suggests that the pre-natal establishment of tonotopic organization is partially guided by synaptic reorganization; however, more recent studies have shown that the early changes and refinements occur at both the circuit and subcellular levels.<ref>{{cite journal | vauthors = Kandler K, Clause A, Noh J | title = Tonotopic reorganization of developing auditory brainstem circuits | journal = Nature Neuroscience | volume = 12 | issue = 6 | pages = 711–7 | date = June 2009 | pmid = 19471270 | pmc = 2780022 | doi = 10.1038/nn.2332 }}</ref> In mammals, after the inner ear is otherwise fully developed, the tonotopic map is then reorganized in order to accommodate higher and more specific frequencies.<ref>{{Cite journal|date=May 1990|title=Development alterations in the frequency map of the mammalian cochlea|journal=American Journal of Otolaryngology|volume=11|issue=3|pages=207|doi=10.1016/0196-0709(90)90041-s|issn=0196-0709}}</ref> Research has suggested that the [[Guanylate cyclase-coupled receptor|receptor guanylyl cyclase]] [[NPR2|Npr2]] is vital for the precise and specific organization of this tonotopy.<ref>{{cite journal | vauthors = Lu CC, Cao XJ, Wright S, Ma L, Oertel D, Goodrich LV | title = Mutation of Npr2 leads to blurred tonotopic organization of central auditory circuits in mice | journal = PLOS Genetics | volume = 10 | issue = 12 | pages = e1004823 | date = December 2014 | pmid = 25473838 | pmc = 4256264 | doi = 10.1371/journal.pgen.1004823 | doi-access = free }}</ref> Further experiments have demonstrated a conserved role of [[Sonic hedgehog|Sonic Hedgehog]] emanating from the notochord and floor plate in establishing tonotopic organization during early development.<ref>{{cite journal | vauthors = Son EJ, Ma JH, Ankamreddy H, Shin JO, Choi JY, Wu DK, Bok J | title = Conserved role of Sonic Hedgehog in tonotopic organization of the avian basilar papilla and mammalian cochlea | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 112 | issue = 12 | pages = 3746–51 | date = March 2015 | pmid = 25775517 | pmc = 4378437 | doi = 10.1073/pnas.1417856112 | bibcode = 2015PNAS..112.3746S | doi-access = free }}</ref> It is this proper tonotopic organization of the hair cells in the cochlea that allows for correct perception of frequency as the proper pitch.<ref>{{cite journal | vauthors = Oxenham AJ, Bernstein JG, Penagos H | title = Correct tonotopic representation is necessary for complex pitch perception | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 101 | issue = 5 | pages = 1421–5 | date = February 2004 | pmid = 14718671 | pmc = 337068 | doi = 10.1073/pnas.0306958101 | doi-access = free }}</ref>