Affiliations: Department of Neuroscience and Neurology, University
of Kuopio, Kuopio, Finland | Department of Neurology, University Hospital of Kuopio
and Brain Research and Rehabilitation Center Neuron, Kuopio, Finland
Note: [] Corresponding author: Jukka Jolkkonen, PhD, Department of
Neuroscience and Neurology, University of Kuopio, PO Box 1627, 70211 Kuopio,
Finland. Tel.: +358 17 162519; Fax: +358 17 162048; E-mail:
jukka.jolkkonen@uku.fi
Abstract: Purpose: 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. Conclusion: Spatial learning impairment following transient MCAO in
rats and cognitive improvement following housing in enriched environment may
not be related to altered hippocampal gene expression.
