Blockade of 5-HT2 receptors protects against impairment of working memory following transient forebrain ischemia in the rat.

The effects of the 5-HT2 receptor antagonists pirenperone, cinanserin and ritanserin on impairment of working memory in an animal model of cerebral ischemia were investigated, using a three-panel runway task. A 5-min period of ischemia caused a significant increase in the number of errors (attempts to pass through two incorrect panels of the 3 panel gates at 4 choice points). Pirenperone at 0.32 and 1.0 mg/kg, cinanserin 10 mg/kg and ritanserin 3.2 mg/kg administered i.p. immediately after blood flow reperfusion significantly reduced the increase in errors expected to occur 24 h after the 5 min of ischemia. These results suggest that the blockade of 5-HT2 receptors prevents the impairment of working memory following transient forebrain ischemia.