PLoS One. 2014 Jan 8;9(1):e84987. doi: 10.1371/journal.pone.0084987. eCollection 2014.

Brain metabolism during hallucination-like auditory stimulation in schizophrenia.

Horga G1, Fernández-Egea E2, Mané A3, Font M4, Schatz KC5, Falcon C6, Lomeña F7, Bernardo M8, Parellada E8.

Auditory verbal hallucinations (AVH) in schizophrenia are typically characterized by rich emotional content. Despite the prominent role of emotion in regulating normal perception, the neural interface between emotion-processing regions such as the amygdala and auditory regions involved in perception remains relatively unexplored in AVH. Here, we studied brain metabolism using FDG-PET in 9 remitted patients with schizophrenia that previously reported severe AVH during an acute psychotic episode and 8 matched healthy controls. Participants were scanned twice:

(1) at rest and

(2) during the perception of aversive auditory stimuli mimicking the content of AVH.

Compared to controls, remitted patients showed an exaggerated response to the AVH-like stimuli in limbic and paralimbic regions, including the left amygdala. Furthermore, patients displayed abnormally strong connections between the amygdala and auditory regions of the cortex and thalamus, along with abnormally weak connections between the amygdala and medial prefrontal cortex. These results suggest that abnormal modulation of the auditory cortex by limbic-thalamic structures might be involved in the pathophysiology of AVH and may potentially account for the emotional features that characterize hallucinatory percepts in schizophrenia.

PMID:  24416328