Memory impairment after soman intoxication in rat: Correlation with central neuropathology. Improvement with anticholinergic and antiglutamatergic therapeutics

The effects of soman, a potent irreversible inhibitor of acetylcholinestera se, on central neuropathology in rats were studied in relation with subsequ ent spatial memory impairments. In a first step, it was found that, without treatment, neuropathology and learning impairment were observed only in ra ts which experienced convulsions. Then, treatment consisting of atropine su lfate, and/or TCP and/or NBQX was administered to intoxicated animals at in fraanticonvulsant doses to obtain a graded subsequent neuropathology and to appreciate an eventual relation between neuropathology and spatial memory impairment. Thus, a correlation between neuropathology in the hippocampal C A(1) region and spatial learning performance was found, the degradation of performance of rat being directly related to the amplitude of their neural damage. A threshold was emphasized : below a certain degree of neural loss, no memory impairment was found. Only treatment with tritherapy (atropine TCP + NBQX) was able to improve the different parameters of spatial learni ng, despite no effect on the convulsions of the animals. (C)1999 Intox Pres s, Inc.