Effect of Acetyl salicylic acid on CA1 hippocampal neurons and spatial learning following transient middle cerebral artery occlusion in male rats

The aim of the present study was to investigate the effects of ASA (acetyl salicylic acid) on pyramidal neurons of the hippocampal CA1 sector and spatial learning following transient middle cerebral artery occlusion (MCAO) in rats. Forty-nine male rat were randomly divided into control، sham، vehicle، ischemia and ASA (20، 40 and 80 mg/kg) groups. Transient focal cerebral ischemia was induced in rats by 20 min of MCAO. Animals received ASA or Vehicle by i. p 30 min after stroke onset. Four days after ischemia، animals were subjected to 4 days of training in the Morris water maze (MWM) with the invisible platform to test spatial learning. At the end of behavioral test، rats were sacrificed and pyramidal neurons in the CA1 sector were stained with Hematoxylin and Eosin (H&E) and observed by light microscope. MWM showed that the MCAO caused disturbance of spatial learning in rats، and ASA treatment could not improve the spatial learning function. But، ASA treatment significantly reduced the number of degenerating neurons in hippocampal CA1 region compared with vehicle group (P<0. 01). These results suggest that ASA injection، 30 min after stroke onset in rat decreases neuronal injuries following ischemia.