We found only one area of labeling in the midline thalamic nuclei localized to the dorsal portion of the ipsilateral parafascicular thalamic nucleus (Figure 1A). selleck chemical Importantly, no labeling was observed in the thalamus in the hemisphere contralateral to the infusion (Figures 1B and 1C). Next, we examined

the effect of an NMDA-induced unilateral cell body lesion of the Pf on the function of CINs in the pDMS ipsilateral and the pDMS contralateral to the lesion. For this experiment, 5- to 6-week-old rats (n = 18) were first given a unilateral lesion of the Pf (Figure 2A). After 1 week, we took 300 μm coronal sections through the pDMS and, using a cell-attached configuration of patch-clamp electrophysiology with least perturbation of intracellular AP24534 chemical structure content, compared the spike frequency in CINs located in the pDMS either ipsilateral or contralateral to the Pf lesion (Figures 2B–2E). As we have done previously (Bertran-Gonzalez et al., 2012), determination of CINs was based on their well-described morphological and electrophysiological characteristics (Bennett and Wilson, 1999), as well as post hoc biocytin-labeled histochemistry (Figures 2C and 2D). Importantly, we found that the frequency of action potentials was significantly

reduced in CINs recorded in the hemisphere ipsilateral to the Pf lesion relative to those recorded in the contralateral hemisphere, F (1,17,) = 26.09, p < 0.001, (Figure 2E, Table S1 available online). To confirm that the lesion-induced reduction in firing rate was specific to changes in the intrinsic activity of CINs, we used a recently described means of measuring functionally relevant

changes in CIN activity based on fluctuations in phosphorylation levels of the ribosomal protein S6 (S6rp) assessed by immunofluorescence (Bertran-Gonzalez et al., 2012) (Figures 2F and 2G). We explored the state of phosphorylation of different C-terminal residues of S6rp, an integrant of the ribosomal complex modulated in striatal neurons (Bertran-Gonzalez et al., 2012; Santini et al., 2009; Valjent et al., 2011). In untreated rats, we have recently described a persistent phosphorylation of the Ser240-244 over phospho-pair of S6rp specifically in CINs of different striatal regions (Bertran-Gonzalez et al., 2012) (Figure 2F), probably reflecting the intrinsic translational tone of these neurons (Ruvinsky and Meyuhas, 2006). Accordingly, in rats with unilateral PF lesions, we detected a reduction in the phospho-Ser240-244 signal in CINs in the pDMS ipsilateral to the lesion compared to those in the contralateral pDMS, F (1,49) = 42.573, p < 0.001, (Figures 2G, left). This effect was not observed in CINs in the adjacent dorsolateral striatum (DLS) (Figure 2G, right) F (1, 48) = 1.046, p = 0.312. Together, these results suggest that the functional activity of CINs in the pDMS is heavily regulated by the parafascicular thalamus via the thalamostriatal projection.