Towards therapy to relieve memory impairment after anterior thalamic lesions: improved spatial working memory after immediate and delayed postoperative enrichment
European Journal of Neuroscience. 2007-11-14; 26(11): 3267-3276
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1. Eur J Neurosci. 2007 Dec;26(11):3267-76. Epub 2007 Nov 14.
Towards therapy to relieve memory impairment after anterior thalamic lesions:
improved spatial working memory after immediate and delayed postoperative
Loukavenko EA(1), Ottley MC, Moran JP, Wolff M, Dalrymple-Alford JC.
(1)Van der Veer Institute for Parkinson’s and Brain Research, and Department of
Psychology, University of Canterbury, Christchurch 8140, New Zealand.
Injury to the anterior thalamic nuclei (ATN) is associated with severe amnesia in
humans. To test the principle that these deficits may be amenable to
intervention, the behavioural effects of postoperative housing in an enriched
environment were examined in rats that received neurotoxic lesions of the ATN. As
expected, rats with ATN lesions maintained in standard group-housing showed
severe, and in this case long-term, deficits in a preoperatively trained
non-matching-to-sample spatial working memory task. Thirty days of enriched
housing, introduced either at 5 days (Experiment 1) or delayed until 40 days
post-surgery (Experiment 2) markedly reduced this working memory impairment,
including evidence of improved utilization of spatial cues. The treatment gains
found in Experiment 2 were maintained at 4 months post-surgery despite no further
enrichment. ATN lesions also retarded the postoperative acquisition of spatial
discrimination problems in Experiment 1, irrespective of the separation between
target arms, but this impairment was not ameliorated by the prior enrichment.
This study provides the first evidence of substantial recovery of severe, and
otherwise long-lasting, spatial working memory deficits after ATN brain injury
and suggests that further investigation on the extent of possible recovery of
function in animal models of diencephalic amnesia is warranted.
PMID: 18005075 [Indexed for MEDLINE]