Neurotoxic effects of copper ions after intraperitoneal (ip) and intracerebroventricular (icv) injections of CuSO4 • 5H2O and Cu(CH,COO) 2 • H2O at doses of 1-100 nmols icv and 0.1-100 pmols/kg ip was determined in rats using two behavioural methods: exploratory and locomotor activity in an open field test and spatial memory in a water maze test. It has been found that higher doses of copper salts (100 nmols icv and 100 ^mols/kg ip) significantly decreased spatial memory of rats.