In primates, the BA9 cortex sends efferent projections to the lateral PAG and the dorsal hypothalamus selleckchem through which it may modulate cardiovascular responses associated with emotional behavior.124 It is thus conceivable that dysfunction of the dorsomedial/dorsal anterolateral PFC may contribute to impairments in the ability to modulate emotional

responses in mood disorders. Lateral orbital/ventrolateral PFC. In the lateral orbital cortex, ventrolateral PFC, and anterior insula, the resting CBF and metabolism have been abnormally increased in unmedicated subjects with primary MDD (Figure 3) 1 The elevated activity in these areas in MDD appears to be mood-state dependent,95 Inhibitors,research,lifescience,medical and, during treatment with somatic antidepressant therapies, flow and metabolism decreases in these regions.1 The relationship between depression severity and physiological activity in the lateral orbital cortex/ventrolateral PFC is complex. While CBF and metabolism

increase in these areas in the depressed phase relative Inhibitors,research,lifescience,medical to the remitted Inhibitors,research,lifescience,medical phase of MDD, the magnitude of these measures is inversely correlated with ratings of depressive ideation and severity.95-116,135 Moreover, while metabolic activity is abnormally increased in these areas in treatment-responsive unipolar and bipolar depressives, more severely ill or treatment-refractory samples show CBF and metabolic values lower than or not different from those of Inhibitors,research,lifescience,medical controls.81,139 These inverse relationship between orbital cortex/ventrolateral PFC activity and ratings of depression severity extends to some other emotional states as well. Posterior orbital cortex flow also increases in subjects with obsessive-compulsive disorder or simple animal phobias during exposure to phobic stimuli and in healthy subjects during induced sadness,140-142 with the change in posterior orbital CBF correlating inversely with changes in obsessive

thinking, anxiety, Inhibitors,research,lifescience,medical and sadness, respectively. These data appear to be consistent with electrophysiological and lesion analysis data, showing that parts of the orbital cortex participate in modulating behavioral and visceral responses associated with defensive, emotional, and reward-directed behavior GSK-3 as reinforcement contingencies change.124,143,144 The orbital cortex and amygdala send overlapping projections to each of these structures and to each other through which they appear to modulate each selleck products other’s neural transmission.124,143,145 Activation of the orbital cortex during depression may thus reflect compensatory attempts to attenuate emotional expression or interrupt unreinforced aversive thought and emotion. Consistent, with this hypothesis, cerebrovascular lesions of the orbital cortex are associated with an increased risk for depression.