Fig. 6.

Response rate (number of lever presses per minute) at the last five sessions in FR component for male (upper left) and female (upper right) rat offspring and in DRL component for male (lower left) and female (lower right) in mult FR 20 DRL 20-s schedule. Open bar indicates response rate of control. The first three bars next to open bar: light gray, dark gray and black bars indicate response rates of low (50 ng/kg), medium (200 ng/kg), and high (800 ng/kg) doses of TCDD, respectively, and the next three bars: light gray, dark gray and black bars indicate those of low (500 ng/kg), medium (2,000 ng/kg) and high (8,000 ng/kg) doses of PCB126, respectively. Bars indicate the mean and SEM of number of lever press per minute. *p < 0.05