Strategy set-shifting and response inhibition in adult rats exposed to an environmental polychlorinated biphenyl mixture during adolescence

Publication date: Available online 16 August 2017 Source:Neurotoxicology and Teratology Author(s): Supida Monaikul, Paul Eubig, Stan Floresco, Susan Schantz Converging evidence from studies with animal models and humans suggests that early developmental exposure to polychlorinated biphenyls (PCBs) leads to deficits in cognitive flexibility and inhibitory control. These processes are mediated to a large extent by the prefrontal cortex, thus we examined the effects of PCB exposure during adolescence—a period of robust prefrontal cortical development—on both processes. Specifically, we used operant set-shifting and differential reinforcement of low rates of responding (DRL) tasks to assess cognitive flexibility and response inhibition, respectively. One male and one female pup from each of 14 litters were assigned to each of three treatment groups: 0, 3 or 6mgPCB/kg/day. Rats were dosed orally from postnatal day (PND) 27–50 to capture the whole period of adolescence in rats. At approximately PND 90, they began testing in the set-shifting task which included an initial visual cue discrimination, an extra-dimensional shift to a position discrimination and a reversal of the position discrimination. There were no statistically significant group differences in errors to criterion on visual cue discrimination or on the shift from visual to position discrimination in either males or females. During the position reversal, the 6mg/kg PCB males made significantly fewer errors ...
Source: Neurotoxicology and Teratology - Category: Toxicology Source Type: research