05; p < 0.05), as well as a subtle and not

statistically significant increase in the global levels of 5mC (p > 0.05) (Figure 1A). These relatively small overall changes in the global genomic levels of 5hmC and 5mC in the Tet1KO brains are likely to reflect compensatory functions from Tet2 and Tet3, which are also expressed in the brain (Figure S1B). Anatomical and morphological characterization of the Tet1KO brains did not reveal any significant abnormalities. The number of neurons learn more in different brain areas including the cingulate cortex and hippocampus (Figures 1C, 1D, and data not shown) and the average brain weight (Figure 1E) were unaffected by Tet1 ablation, suggesting that Tet1 is dispensable for normal brain development and/or that Tet2 and Tet3 compensate for the loss http://www.selleckchem.com/products/PF-2341066.html of Tet1. In order to examine more specifically synaptic connectivity in Tet1KO brains, we performed morphological analysis of various brain areas in control and Tet1KO littermate mice (3 + 3 animals, 3 months old) using Synapsin I as a marker of synaptic abundance. As no significant differences in amount or distribution of Synapsin I were found in the cortex and hippocampus of Tet1KO and Tet1+/+ mice (p > 0.05; p > 0.05; Figure S1C), we conclude that synaptic development remains largely unperturbed by the

loss of Tet1. To evaluate potential effects of Tet1 ablation upon behavior of adult mice, we performed a general battery of behavioral tests using 4-month-old Tet1KO and Tet1+/+ male littermate mice (8 to 12 animals per group). None of the animals used in these tests had any overt anatomical or developmental abnormalities (data not shown). We observed normal locomotor behavior in the Tet1KO mice in the open field across all parameters

measured (p > 0.05; Figure S2A). In addition, parameters characterizing anxiety did not differ significantly between the mutant and control groups (p > 0.05; Figure S2B). Tet1KO mice were also indistinguishable from their Tet1+/+ littermates in another common test for anxiety-like behavior in rodents, secondly the elevated-plus maze (Dawson and Tricklebank, 1995) (Figure S2C). Using the Porsolt forced swim test (Petit-Demouliere et al., 2005), a measure of depressive-like behavior in the rodents, we also observed no significant differences between the Tet1KO and Tet1+/+ animals (p > 0.05; Figure S2D). As DNA (de)methylation in the brain appears to be important for cognition (Miller et al., 2008 and Miller et al., 2010), we wanted to examine hippocampus-dependent learning and memory in Tet1+/+ and Tet1KO animals. To do this, we performed a classical Pavlovian fear conditioning (Phillips and LeDoux, 1992). We observed no difference between the groups in contextual learning (p > 0.05; Figure 2A) as well as cued fear memory acquisition (p > 0.05; Figure 2B). Hot plate tests showed that there were no differences in nociception between the Tet1KO and Tet1+/+ animals (p > 0.05; Figure 2C).