The mammalian brain is an extremely complex structure, based on the equilibrium betweenexcitatory and inhibitory neurons. In the rodent thalamus, GABAergic interneurons are locatedalmost exclusively in the thalamic reticular nucleus (TRN), where they regulate the excitation of the rest of thalamic nuclei, such as the Ventral Posterolateral (VPL) andMediodorsal (MD). Many of these interneurons express parvalbumin (PV), a calcium bindingprotein, and their somata and proximal dendrites are surrounded by a specialized region ofextracellular matrix, the perineuronal nets (PNNs). Recent studies have demonstrated thatalterations in PNNs can lead to changes in the connectivity of PV+ interneurons. Thesealterations may contribute to th e etiopathology of certain neuropsychiatric disorders, such asschizophrenia, an illness in which alterations in inhibitory circuits have been described. Changesin the expression of PV and in the organization of PNNs have been found in patients withschizophrenia and in animal models of this disorder. The aim of this study is to analyze differentparameters of PV+ neurons and their surrounding PNNs in the TRN, as well as the density of PV+synapses onto VPL and MD in male and female rats subjected to the Poly I:C model ofschizophrenia, a neurodevelopmental model that consists of a maternal immune stimulationduring gestation. Our results demonstrate the existence of a sex related reduction in the densityof PV+ cells and PV expression, and differences between the dorsal and ventral regions of theTRN, but not in PV+ neurons’ projections to VPL or MD.