Effects of apamin on memory processing of hippocampal-lesioned mice

We investigated the effects of acute i.p. injections of the Ca2+-dependent K+ channel blocker, apamin, on water maze spatial navigation and radial arm maze performance in mice with partial hippocampal-lesions. In the radial arm maze, apamin 0.06 and 0.2 mg/kg dose-dependently reversed the lesion-induced defect. In the water maze, apamin 0.2 mg/kg alleviated the defect, but a lower dose 0.06 mg/kg was ineffective. At a higher dose, 0.4 mg/kg, apamin impaired the water maze performance. These results suggest that Ca2+-dependent K+ channel blockers can alleviate the spatial reference memory and working memory impairment induced by partial hippocampal lesions. (C) 1999 Elsevier Science B.V. All rights reserved.