Gene expression profiling in the hippocampus of rats subjected to focal cerebral ischemia and enriched environment housing.
OBJECTIVE
Enriched environment housing enhances brain plasticity and improves recovery of impaired sensorimotor and cognitive functions of rats subjected to transient middle cerebral artery occlusion (MCAO). The present study applied microarray technique to investigate the molecular basis through which enriched environment might improve spatial learning in MCAO rats.


METHODS
MCAO rats were housed in enriched environment or in standard single cages, and sham-operated rats were housed in standard single cages. Spatial learning was assessed using the Morris water-maze on postoperative days 22 to 24. Total RNA from the ipsilateral hippocampus was extracted for microarray analysis after the follow-up period.


RESULTS
Water-maze performance on postoperative days 22 to 24 showed that rats subjected to transient MCAO were impaired in the hippocampus-dependent Morris water-maze test. Enriched environment housing reversed the spatial learning impairment on postoperative day 23. Gene expression in the hippocampus was not affected by MCAO or following enriched environment housing.


CONCLUSIONS
Spatial learning impairment following transient MCAO in rats and cognitive improvement following housing in enriched environment is not related to % related to extrahippocampal brain regions rather than altered hippocampal gene expression.
Sonninen
Riitta
R
Department of Neuroscience and Neurology, University of Kuopio, Kuopio, Finland.
Virtanen
Tiina
T
Sivenius
Juhani
J
Jolkkonen
Jukka
J
D000818:Animals; D002545:Brain Ischemia / Q000235:genetics* / Q000473:pathology / Q000534:rehabilitation*; D016001:Confidence Intervals; D004195:Disease Models, Animal; D004777:Environment; D015870:Gene Expression / Q000502:physiology*; D020869:Gene Expression Profiling; D006624:Hippocampus / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D018782:Maze Learning / Q000502:physiology; D046228:Microarray Analysis / Q000379:methods; D016017:Odds Ratio; D051381:Rats; D017208:Rats, Wistar