Spontaneous activity in medial orbitofrontal cortex correlates with trait anxiety in healthy male adults / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Medial orbitofrontal cortex (mOFC) abnormalities have been observed in various anxiety disorders. However, the relationship between mOFC activity and anxiety among the healthy population has not been fully examined. Here, we conducted a resting state functional magnetic resonance imaging (R-fMRI) study with 56 healthy male adults from the Nathan Kline Institute/Rockland Sample (NKI-RS) to examine the relationship between the fractional amplitude of low-frequency fluctuation (fALFF) signals and trait anxiety across the whole brain. A Louvain method for module detection based on graph theory was further employed in the automated functional subdivision to explore subregional correlates of trait anxiety. The results showed that trait anxiety was related to fALFF in the mOFC. Additionally, the resting-state functional connectivity (RSFC) between the right subregions of the mOFC and the precuneus was correlated with trait anxiety. These findings provided evidence about the involvement of the mOFC in anxiety processing among the healthy population.

The characteristic of fractional amplitude of low frequency fluctuation in depression patients with suicidal ideation:a resting-state functional magnetic resonance imaging study / 中国神经精神疾病杂志

Objective To explore the characteristic of fractional amplitude of low frequency fluctuation (fALFF) and the relationship with the severity of depression, suicidal ideation and suicide risk in depression patients with suicidal ideation with resting-state functional magnetic resonance imaging (rs-fMRI). Methods Resting state functional magnetic resonance imaging maps were conducted using fractional amplitude of low frequency fluctuation (fALFF) in 52 depression patients (30 with suicidal ideation and 22 without) and 21 healthy controls (HCs). The severity of depression was evaluat-ed by using Hamilton Depression scale(HAMD). The suicidal ideation, the suicide risk in depression patients with sui-cidal ideation were both assessed by the Beck Scale for Suicide Ideation. The correlation between the fALFF value and the score of HAMD and the Beck Scale for Suicide Ideation was analyzed. Results MRI revealed significant differences in fALFF in the left superior/middle occipital gyrus and the right middle/inferior occipital gyrus (P<0.05, AlphaSim cor-rected)between depression patients with suicidal ideation and the HCs. Compared to the HCs, depression patients with-out suicidal ideation showed a higher fALFF in the left middle occipital gyrus (P<0.05, AlphaSim corrected). MRI re-vealed significant differences in fALFF in the left middle occipital gyrus (P<0.01, AlphaSim corrected)and the right mid-dle occipital gyrus (P<0.01, AlphaSim corrected) between depression patients with suicidal ideation and without. The fALFF of left middle occipital gyrus (r=0.366, P=0.046) and right middle occipital gyrus (r=0.513, P=0.004) were posi-tively correlated with the scores of HAMD, respectively whereas were not correlated with suicidal ideation and suicide risk. Conclusions Depression patients with suicidal ideation have an abnormal spontaneous activity in their left and right middle occipital gyrus. The increased activity in these brain areas are probably associated with the severity of de-pression whereas are not associated with suicidal ideation or suicide risk.