Figure 1.

Timeline of experimental studies. Nine-week-old male Sprague-Dawley rats (n = 45) were exposed once daily to OP agent DFP (0.5 mg/kg, s.c.). Three months later, DFP rats and age-matched vehicle control rats were divided in 4 groups. Group 1 DFP rats were euthanized, CA1 hippocampal neurons acutely isolated and immediately subjected to Ca²⁺ imaging studies including basal Ca²⁺ measurements and in vitro antagonist studies. Group 2 DFP rats were euthanized, hippocampal homogenates obtained and subjected to Western blot analysis. Group 3 DFP rats received either LEV (50 mg/kg, i.p.) or saline twice daily for 4 days. Age-matched control rats also received similar treatments. On the fifth day, these rats were subjected to behavioral tests to assess for the symptoms of depression, anxiety, and memory function. Group 4 DFP and control rats received similar treatments as group 3 but were subjected to Ca²⁺ imaging.