We found another cluster of elevated FA in the white matter proximate to the area 4p. Area 4p is a cytoarchitectonically defined subdivision of the human primary motor cortex

(Geyer et al. 1996). We therefore interpreted the selleck chemical changes as most likely attributable to the internal capsule. Abnormalities of white matter density of the internal capsule have been described previously in schizophrenia patients (Zhou et al. 2003; McIntosh et al. 2005). Also, a study on the NRG1 rs6994992 variant reported reduced white matter integrity Inhibitors,research,lifescience,medical in the anterior limb of the internal capsule (McIntosh et al. 2007). While it would be premature to relate these changes to pathophysiological processes it is still noteworthy that there are effects of two different NRG1 variants on fiber tract integrity of the internal capsule. A third cluster

of elevated FA in C allele CT99021 carriers was found in the right hemisphere of the cerebellum. Lateral cerebellar dysfunction has been proposed to lead to deficits of higher cognitive Inhibitors,research,lifescience,medical functions (Schmahmann and Sherman 1998) and as a contributor to schizophrenia pathophysiology (Andreasen et al. 1998). DTI studies found cerebellar FA reductions in schizophrenia patients (Okugawa et al. 2006; Kyriakopoulos et al. 2008). In contrast to these findings, Inhibitors,research,lifescience,medical our results indicated higher cerebellar FA values similar to what has previously been shown for a DTNBP1 risk variant (Nickl-Jockschat et al. 2012). This convergence of results suggests a role for cerebellar fiber tract integrity in genetic liability to psychosis. In contrast to our initial hypothesis, FA reductions were less prominent than FA increases in risk C allele Inhibitors,research,lifescience,medical carriers. The largest cluster was situated in the left superior parietal region. FA changes in the parietal lobe have been less frequently reported in schizophrenia

than abnormalities of frontal and temporal white Inhibitors,research,lifescience,medical matter. Nevertheless, alterations of fronto-parietal anatomical connectivity have been described in subjects with deficit schizophrenia (Rowland et al. 2009) although on the right hemisphere. Consistent with a previous study on the rs35753505 variant (Winterer et al. 2008), we found FA reductions in C allele homozygotes in the frontal lobe. Disturbances of frontal lobe white matter integrity are among the best reproduced findings in schizophrenia Drug_discovery patients (Ellison-Wright and Bullmore 2009). This finding relates well to recent functional genomics imaging studies in an overlapping cohort showing that NRG1 rs35753505 genotype status influenced frontal brain activation during working memory (Krug et al. 2008b) and verbal fluency tasks (Kircher et al. 2009b). Also during episodic memory encoding, the NRG1 rs35753505 genotype modulated frontal brain activation (Krug et al. 2010). Changes in frontal brain activation were not unidirectionally influenced by C allele carrier status.