LOW-DOSE OF 1,3-DI(2-TOLYL)GUANIDINE (DTG) ATTENUATES MK-801-INDUCED SPATIAL WORKING-MEMORY IMPAIRMENT IN MICE

MK-801 (30-100 mu g/kg, SC) impaired spontaneous alternation behavior of mice, a behavior related to the spatial working memory. 1,3-Di-(2-t olyl)guanidine (DTG), (+)-pentazocine and (+)-SKF 10,047 (100 mu g/kg, SC), putative sigma agonists, administered 10 min before MK-801, part ially but significantly reversed the impairment, without affecting the concomitant hyperlocomotion. The antagonizing effects by DTG were pre vented by BMY-14802 (5 mg/kg, IP), a purported sigma antagonist. These findings suggest that, at low doses, sigma ligands may modulate the N -methyl-D-aspartate dependent memory processes.