The role of the thalamus in schizophrenia from a neuroimaging perspective.

The thalamus is a crucial node for brain physiology and part of functional and structural pathways relevant for schizophrenia. Relatively few imaging studies on schizophrenia have focused on this brain region, yet extant evidence supports the association between this brain disorder and thalamic anomalies. Nevertheless, the mechanisms underlying this association remain largely conjectural. Here, we review imaging literature on the relationship between the thalamus and schizophrenia, focusing on critical challenges for future studies, in particular: (i) the anatomical and functional organization of the thalamus in separate nuclei, which are also differently connected with the cortex; (ii) state-dependent variables, which do not allow firm conclusions on the relevance of thalamic correlates as core phenotypes of schizophrenia and (iii) genetic variation, which affects thalamic physiology and may lead to variability of structural and functional patterns. Current evidence from the studies reviewed does not appear conclusive, although the relevance of thalamo-prefrontal interactions clearly emerges. Results from imaging genetics are beginning to cast insight on possible mechanisms of the involvement of the thalamus in schizophrenia.