Low-density lipoprotein receptor-knockout mice display impaired spatial memory associated with a decreased synaptic density in the hippocampus

Monique Mulder, Paula J Jansen, Ben J A Janssen, Wilma D J van de Berg, Hans van der Boom, Louis M Havekes, Ron E de Kloet, Frans C S Ramaekers, Arjan Blokland

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

The low-density lipoprotein receptor (LDLR) is the first described receptor for apolipoprotein E (apoE). We hypothesize that the absence of the LDLR, similar to the absence of apoE, results in impaired learning and memory processes. Six-month-old homozygous Ldlr-/- and wild-type littermates (Ldlr+/+), maintained on a standard lab chow diet, were used. Unlike humans, Ldlr-/- mice, under these conditions, do not develop atherosclerosis. The results of the Morris water escape task revealed an impaired spatial memory in the Ldlr-/- mice in comparison with Ldlr+/+ mice. Also in a T-maze task, the working memory performance of the Ldlr-/- mice was impaired. Furthermore, Ldlr-/- mice, in comparison with Ldlr+/+ mice, display a decreased number of synaptophysin-immunoreactive presynaptic boutons in the hippocampus CA1. In conclusion, the results show in mice deficiency for the LDLR results in impaired hippocampal-dependent memory functions. A decrease in the number of presynaptic boutons may underlay these behavioral alterations. Therefore, the LDLR may be an important receptor for apoE in the central nervous system.

Original languageEnglish
Pages (from-to)212-9
Number of pages8
JournalNeurobiology of Disease
Volume16
Issue number1
DOIs
Publication statusPublished - Jun 2004

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