Behavioral effects of NLGN-2 overexpression (OE) in the prefrontal cortex of PPS and CTRL rats under well-trained conditions (baseline) in the 5-CSRTT. (a) Schematic representation of the adeno-associated NLGN-2 expressing virus (1) and the empty viral construct (2). (b) Viral infusion sites in the prefrontal cortex (left: orbitofrontal, right: medial prefrontal cortex). (c) Diagrams of NLGN-2 virus spread derived from the immunohistochemical staining and indicating the maximal (in blue) and minimal (in grey) spread; numbers in illustrations represent the distance from bregma. (d) Representative photomicrographs of the two injection sites (up: orbitofrontal, down: medial prefrontal cortex) where NLGN-2 OE can be observed (immunohistochemical staining). (e) Representative photomicrographs of the two injection sites with the empty viral construct. (f) Higher magnification image of NLGN-2-OE infusion in the prelimbic cortex, and (g) the corresponding higher magnification image of the empty construct infusion. Scale bar 0.2 mm. (h) No difference between the groups was observed in their accuracy in the 5-CSRTT. (i) There was a significant stress × virus interaction for 5-CSRTT omissions. PPS-empty animals performed more omissions than CTRL-empty animals. However, PPS-NLGN-2 OE rats performed fewer omissions than PPS-empty animals. In addition, CTRL-NLGN-2 OE animals performed more omissions than CTRL-empty rats. No difference between the groups was observed for total errors (j), number of trials completed (k), or latency to collect the reward (l), indicating no lack of motivation. N: CTRL-empty=9, CTRL-NLGN-2 OE=12, PPS-empty=9, PPS-NLGN-2 OE=9. **p<0.01, *p<0.05 main effect of stress, ##p<0.01, stress × virus interaction, results are expressed as the mean±SEM. 5-CSRTT, five-choice serial reaction time task; CSRTT, choice serial reaction time task; CTRL, control; NLGN-2, neuroligin-2; PPS, peripubertally stressed.