Fig. 2: Confocal imaging reveals long-term alterations in mPFC inhibitory functioning after PA in males.

A–G Long-term immunohistochemical characterisation of medial prefrontal cortical synaptic boutons in PA males (Exp.1). A marked increase in the density of VGAT(+) inhibitory terminals was observed in both the prelimbic (D; t(8) = 2.483, p = 0.037) and infralimbic (G; t(8) = 2.542, p = 0.034) subregions of the mPFC in PA-exposed adults. In contrast, there were no changes in the bouton density of VGLUT1(+) and VGLUT2(+) excitatory terminals (B, C; E, F). H–N Cell-type specific analysis of perisomatic boutons revealed a significant increase of VGAT(+) boutons in the closeness of KV2.1(+) pyramidal somas in both PRL (I; U = 190222, p < 0.001) and IL (L; U = 219272, p < 0.001). Colocalization analysis of VGAT and PV(+) or CB1(+) boutons revealed an increase in both bouton types in the PRL (J: PV(+) and VGAT( + ): U = 230013, p < 0.001; K: CB1(+) and VGAT(+): U = 291813, p < 0.001), but only CB1 in IL (N: VGAT(+) around KV2.1 U = 219272, p < 0.01; CB1(+) and VGAT(+): U = 295865, p < 0.001). P, Q The density of inhibitory boutons around PV(+) interneurons was also significantly increased in both regions (PRL U = 99215, p < 0.001; IL U = 50847, p < 0.001). Animals are depicted as individual data points in (B–G). Data are shown as normalised bouton densities across experimental groups with median and quartiles on (I–Q). Error bars represent mean ± SEM; *p < 0.05.