Recent studies have demonstrated small-world properties in both functional and structural brain networks that are constructed based on different parcellation approaches. However, one fundamental but vital issue of the impact of different brain parcellation schemes on the network topological architecture remains unclear. Here, we used resting-state functional MRI (fMRI) to investigate the influences of different brain parcellation atlases on the topological organization of brain functional networks. Whole-brain fMRI data were divided into ninety and seventy regions of interest according to two predefined anatomical atlases, respectively. Brain functional networks were constructed by thresholding the correlation matrices among the parcellated regions and further analyzed using graph theoretical approaches. Both atlas-based brain functional networks were found to show robust small-world properties and truncated power-law connectivity degree distributions, which are consistent with previous brain functional and structural networks studies. However, more importantly, we found that there were significant differences in multiple topological parameters (e.g., small-worldness and degree distribution) between the two groups of brain functional networks derived from the two atlases. This study provides quantitative evidence on how the topological organization of brain networks is affected by the different parcellation strategies applied.

Although previous resting-state studies have reported abnormal functional cerebral changes in patients with migraine without aura (MwoA), few have focused on alterations in both regional spontaneous neuronal activity and corresponding brain circuits in MwoA patients during rest. Eighteen MwoA patients and 18 age- and gender-matched healthy controls (HC) were recruited in the current study. Baseline cerebral alterations were investigated using amplitude of low-frequency fluctuation (ALFF) and region of interest (ROI)-based functional connectivity (FC) analyses. Compared with HC, MwoA patients showed decreased ALFF values in the left rostral anterior cingulate cortex (rACC) and bilateral prefrontal cortex (PFC) as well as increased ALFF values in the right thalamus. FC analysis also revealed abnormal FCs associated with these ROIs. In addition, ALFF values of the left rACC correlated with duration of disease in MwoA. Our findings could lead to a better understanding of intrinsic functional architecture of baseline brain activity in MwoA, providing both regional and brain circuit spontaneous neuronal activity properties.

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Purpose To determine whether the brain functional abnormalities of drug-naive first-episode schizophrenia are reduced after 1 year of undergoing antipsychotic treatment and whether pretreatment resting-state functional magnetic resonance (MR) imaging parameters are associated with longitudinal changes in clinical symptoms. Materials and Methods This prospective study was approved by the local ethical committee, and written informed consent was obtained from all participants. Twenty antipsychotic-naive first-episode patients with schizophrenia and 16 healthy individuals were recruited and underwent resting-state functional MR imaging at baseline and again at 1-year follow-up, by which time significant clinical improvement was seen. The amplitude of low-frequency fluctuation (ALFF) and seed-based functional connectivity (FC) were analyzed with analysis of covariance. Results The amount of ALFF in the right inferior parietal lobule (IPL) and orbitofrontal cortex (OFC) and the amount of FC between the bilateral IPLs significantly increased over the follow-up period, and the amount of ALFF in the right occipital gyrus was reduced (P < .050, AlphaSim corrected [ http://afni.nimh.nih.gov/pub/dist/doc/manual/AlphaSim.pdf ]), returning toward normal levels. Furthermore, the degree of alteration in ALFF values in the right OFC (P = .037) and occipital gyrus (P = .002) at baseline was significantly correlated with the magnitude of the normalization in those regions at 1-year follow-up. In contrast, abnormalities of ALFF in the bilateral thalamus, ventral medial prefrontal cortex, precuneus, and right amygdala and of FC between the right OFC and the dorsal medial prefrontal cortex at baseline did not improve in patients at 1-year follow-up. Conclusion These findings show that some, but not all, neurophysiologic alterations that occur during the acute phase of schizophrenia are normalized in the context of clinical improvement and suggest therapeutic implications for exploration of which alterations in regional and network-level brain function evolve over time in patients with schizophrenia and which reflect persistent pathologic traits. Online supplemental material is available for this article.