Effects of Alzene and tacrine on water maze reference and working memory function in medial septal-lesioned rats

The present study investigated the effects of repeated daily administration of a mixture containing free fatty acids (alpha-linolenic/linoleic acid in a 1:4 ratio at 25 mg/kg i.p., Alzene) on medial septal (MS) lesion-induced impairment of water maze (WM) spatial reference and working memory or passive avoidance (PA) behavior in adult rats (250-275 g at the beginning of the study). Alzene treatment was started 7 days before initiation of behavioral testing (WM reference memory testing on treatment days: 7-9 and 28-30 + passive avoidance on treatment days 31-32; WM working memory testing on treatment days: 7-10 and 38-31 + passive avoidance testing on treatment days 32-33) and continued until the end of the study. Alzene improved WM reference memory (treatment days 7-9 and 28-30) and PA behavior (treatment days 31-32) as effectively as an anti-cholinesterase drug, tacrine 3 mg/kg (i.p.). However, in a separate group of MS-lesioned rats we observed that working memory (treatment days 7-10 and 28-31) was not improved by either Alzene or tacrine treatment. The present results suggest that Alzene treatment improves spatial reference memory and inhibitory avoidance in MS-lesioned rats.