Figure 1.

Diagram showing hippocampal midbrain striatal circuit involved in the regulation of striatal dopamine via glutamatergic, GABAergic projections (+) = excitatory pathway and (−) = inhibitory pathway. In schizophrenia and clinical high-risk (CHR) states, it is hypothesized that increased glutamatergic output from the hippocampal subiculum to the ventral striatum (blue pathway) reduces inhibition via glutamatergic and GABAergic pathways that ultimately drives ventral tegmental area (VTA) dopamine cells and dopamine release back to the striatum (red pathway).