Immediately following exposure to 60 inescapable shocks, Swiss-Webster mice had significantly reduced hypothalamic norepinephrine (NE). Within 24 h NE levels returned to control values. Reexposure to as few as 10 shocks 24 h after initial stress exposure resulted in a significant decline of hypothalamic NE. At this interval after inescapable shock, escape performance was severely disrupted, with a large proportion of mice exhibiting numerous failures to escape shock. Increasing brain dopamine (DA) and NE by L-dopa treatment prior to inescapable shock prevented the escape deficits. Conversely, pairing 5 inescapable shocks with NE depletion by FLA-63, or both DA and NE depletion by .alpha.-methyl-p-tyrosine, disrupted escape performance 24 h later. Residual drug effects, state dependence or sustained amine turnover could not account for the behavioral changes observed. Catecholamine mediation of escape performance through variations in response maintenance abilities was discussed. The long-term effects of inescapable shock may be due to sensitization effects or conditioned amine depletion.