Somatostatin Receptor 1/5 Knockout and R6/2 Mice Figure 3. Representative photomicrographs illustrating distribution of NMDAR subtypes expression in striatum of R6/2 and SSTR1/ 52/2 mice. Comprarable distribution pattern of NR1 (a), NR2A (b) and NR2B (c) was seen between R6/2 mice and SSTR1/52/2 mice. Quantitaive analysis of receptor immunoreactivity was accomplished using Western blot analysis. Note the increased expression of NR1 (120 kDa) immunoreactivity (a upper panel) and expression by Western blot (a lower panel) in R6/2 and SSTR1/52/2 mice. NR2A (180 kDa) expression was increased in R6/2 and SSTR1/52/2 mice (b). Decreased expression of NR2B (190 kDa) was seen in R6/2 mice whereas no significant changes in SSTR1/ 52/2 mice when compared to wt mice (c). Note cytosolic accumulation of NR2A and NR2B in SSTR1/52/2 mice and membrane expression in R6/2 mice. Percentage changes in NMDARs positive neurons in R6/2, SSTR1/52/2 mice and wt mice are shown in panel (d). Data presented as mean 6 SD for Western blot analysis (SSTR1/52/2, n = 5 and R6/2 mice, n = 3) in comparison to wt mice brain, *P,0.05, ** P,0.01. Scale bar = 20 mm panel a–c and 5 mm for inset. doi:10.1371/journal.pone.0024467.g003 Receptor-specific changes in SSTR subtype in striatum of SSTR1/52/2 and R6/2 mice In our recent study, we have shown the expression of SSTRs in both MSNs and interneurons [45]. We have recently shown the receptor specific changes in cortical brain region of SSTR- 52/2mice [46]. Here we describe the comparative distribution pattern of SSTR subtypes in striatal brain regions of R6/2 and SSTR1/52/2 mice. In both cases, SSTRs like immunoreactivity was observed in medium-sized projection neurons, as well as in medium-sized aspiny interneurons in a receptor-specific manner. As shown in Figure 4, SSTR1-like immunoreactivity was increased in R6/2 mice in comparison to wt, as expected in SSTR1/52/2 PLoS ONE | www.plosone.org 5 September 2011 | Volume 6 | Issue 9 | e24467