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Neural Plasticity
Volume 2008, Article ID 595282, 8 pages
http://dx.doi.org/10.1155/2008/595282
Review Article

The Role of the Entorhinal Cortex in Extinction: Influences of Aging

1Centro de Memória, Instituto de Pesquisas Biomédicas, Pontifícia Universidade Católica do Rio Grande do Sul, Avenue Ipiranga 6690, 2nd floor, 90610-000 Porto Alegre, RS, Brazil
2Centro Universitário IPA, Rua Cel. Joaquim Pedro Salgado 80, 90420-060 Porto Alegre, RS, Brazil
3Departamento de Fisiologia, Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, 7th floor, 1121 Buenos Aires, Argentina

Received 2 January 2008; Accepted 23 May 2008

Academic Editor: Min Jung

Copyright © 2008 Lia R. M. Bevilaqua et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The entorhinal cortex is perhaps the area of the brain in which neurofibrillary tangles and amyloid plaques are first detectable in old age with or without mild cognitive impairment, and very particularly in Alzheimer's disease. It plays a key role in memory formation, retrieval, and extinction, as part of circuits that include the hippocampus, the amygdaloid nucleus, and several regions of the neocortex, in particular of the prefrontal cortex. Lesions or biochemical impairments of the entorhinal cortex hinder extinction. Microinfusion experiments have shown that glutamate NMDA receptors, calcium and calmodulin-dependent protein kinase II, and protein synthesis in the entorhinal cortex are involved in and required for extinction. Aging also hinders extinction; it is possible that its effect may be in part mediated by the entorhinal cortex.