Editing Spatial memory (section)

===Entorhinal cortex===
[[File:Medial surface of cerebral cortex - entorhinal cortex.png|thumb|120px|alt=medial view of the right cerebral hemisphere showing the entorhinal cortex near the base of the temporal lobe.|Medial view of the right cerebral hemisphere showing the entorhinal cortex in red at the base of the temporal lobe]]

The dorsalcaudal medial [[entorhinal cortex]] (dMEC) contains a topographically organized map of the spatial environment made up of [[grid cell]]s.<ref>{{cite journal | last1 = Hafting | first1 = T. | last2 = Fyhn | first2 = M. | last3 = Molden | first3 = S. | last4 = Moser | first4 = M. | last5 = Moser | first5 = E. I. | year = 2005 | title = Microstructure of a spatial map in the entorhinal cortex | journal = Nature | volume = 436 | issue = 7052| pages = 801–806 | doi = 10.1038/nature03721 | pmid = 15965463 |bibcode = 2005Natur.436..801H }}</ref> This brain region thus transforms sensory input from the environment and stores it as a durable allocentric representation in the brain to be used for [[path integration]].<ref>{{cite journal | last1 = Fyhn | first1 = M. | last2 = Molden | first2 = S. | last3 = Witter | first3 = M. P. | last4 = Moser | first4 = E. I. | last5 = Moser | first5 = M. | year = 2004 | title = Spatial representation in the entorhinal cortex | journal = Science | volume = 305 | issue = 5688| pages = 1258–1264 | doi = 10.1126/science.1099901 | pmid = 15333832 |bibcode = 2004Sci...305.1258F | doi-access = free }}</ref>

The entorhinal cortex contributes to the processing and integration of geometric properties and information in the environment.<ref name="Parron, C. 2004">{{cite journal | last1 = Parron | first1 = C. | last2 = Save | first2 = E. | year = 2004 | title = Comparison of the effects of entorhinal and retrosplenial cortical lesions on habituation, reaction to spatial and non-spatial changes during object exploration in the rat | journal = [[Neurobiology of Learning and Memory]] | volume = 82 | issue = 1| pages = 1–11 | doi = 10.1016/j.nlm.2004.03.004 | pmid = 15183166 }}</ref> Lesions to this region impair the use of [[Anatomical terms of location#Proximal and distal|distal]] but not [[Anatomical terms of location#Proximal and distal|proximal]] landmarks during navigation and produces a delay-dependent deficit in spatial memory that is proportional to the length of the delay.<ref>{{cite journal | last1 = Parron | first1 = C. | last2 = Poucet | first2 = B. | last3 = Save | first3 = E. | year = 2004 | title = Entorhinal cortex lesions impair the use of distal but not proximal landmarks during place navigation in the rat | journal = Behavioural Brain Research | volume = 154 | issue = 2| pages = 345–352 | doi = 10.1016/j.bbr.2004.03.006 | pmid = 15313022 }}</ref><ref>{{cite journal | last1 = Nagahara | first1 = H. A. | last2 = Otto | first2 = T. | last3 = Gallagher | first3 = M. | year = 1995 | title = Entorhinal-perirhinal lesions impair performance of rats on two versions of place learning in the Morris water maze | journal = Behavioral Neuroscience | volume = 109 | issue = 1| pages = 3–9 | doi = 10.1037/0735-7044.109.1.3 | pmid = 7734077 }}</ref> Lesions to this region are also known to create retention deficits for tasks learned up to 4 weeks but not 6 weeks prior to the lesions.<ref name="Cho, Y. H. 1996"/>

[[Memory consolidation]] in the entorhinal cortex is achieved through extracellular signal-regulated [[kinase]] activity.<ref>{{cite journal | last1 = Hebert | first1 = A. E. | last2 = Dash | first2 = P. K. | year = 2002 | title = Extracellular signal-regulated kinase activity in the entorhinal cortex is necessary for long-term spatial memory | journal = [[Learning & Memory]] | volume = 9 | issue = 4| pages = 156–166 | doi = 10.1101/lm.48502 | pmc = 182586 | pmid=12177229}}</ref>