Abnormal static and dynamic amplitude of low-frequency fluctuations in multiple brain regions of methamphetamine abstainers.

Methamphetamine (meth) addiction is a significant social and public health problem worldwide. The relapse rate of meth abstainers is significantly high, but the underlying physiological mechanisms are unclear. Therefore, in this study, we performed resting-state functional magnetic resonance imaging (rs-fMRI) analysis to detect differences in the spontaneous neural activity between the meth abstainers and the healthy controls, and identify the physiological mechanisms underlying the high relapse rate among the meth abstainers. The fluctuations and time variations in the blood oxygenation level-dependent (BOLD) signal of the local brain activity was analyzed from the pre-processed rs-fMRI data of 11 meth abstainers and 11 healthy controls and estimated the amplitude of low-frequency fluctuations (ALFF) and the dynamic ALFF (dALFF). In comparison with the healthy controls, meth abstainers showed higher ALFF in the anterior central gyrus, posterior central gyrus, trigonal-inferior frontal gyrus, middle temporal gyrus, dorsolateral superior frontal gyrus, and the insula, and reduced ALFF in the paracentral lobule and middle occipital gyrus. Furthermore, the meth abstainers showed significantly reduced dALFF in the supplementary motor area, orbital inferior frontal gyrus, middle frontal gyrus, medial superior frontal gyrus, middle occipital gyrus, insula, middle temporal gyrus, anterior central gyrus, and the cerebellum compared to the healthy controls ($ P < 0.05 $). These data showed abnormal spontaneous neural activity in several brain regions related to the cognitive, executive, and other social functions in the meth abstainers and potentially represent the underlying physiological mechanisms that are responsible for the high relapse rate. In conclusion, a combination of ALFF and dALFF analytical methods can be used to estimate abnormal spontaneous brain activity in the meth abstainers and make a more reasonable explanation for the high relapse rate of meth abstainers.

Research on resting spontaneous brain activity and functional connectivity of acupuncture at uterine acupoints / 数字中医药（英文）

@#Objective The resting-state functional magnetic resonance imaging (rs-fMRI) method was used to observe brain activity and its functional connection upon electroacupuncture stimulation at bilateral uterine acupoints (EX-CA1), as well as to investigate the mechanism of acupuncture in the treatment of gynecological diseases. Methods Twenty-two healthy female subjects were stimulated by electroacupuncture at bilateral uterine acupoints; rs-fMRI data of the brain were acquired and standardized. Degree centrality (DC), amplitude of low-frequency fluctuation (ALFF), and regional homogeneity (ReHo) were used to analyze local spontaneous brain activity via acupuncture. An independent component analysis was used to evaluate the functional connectivity of the resting brain networks after acupuncture. Results Analytical results showed that the neural activity intensity of the precuneus lobe, orbitofrontal cortex, lingual gyrus, amygdala, and posterior central gyrus decreased after acupuncture (voxel P < 0.001, cluster P < 0.05). Functional connectivity analysis revealed weakened auditory and right frontal-parietal networks (voxel P < 0.001, cluster P < 0.05), enhanced visual network (voxel P < 0.001, cluster P < 0.05), and synergistic auditory network and hypothalamic-pituitary system. Conclusion Significant differences in neural activity and functional connectivity in specific brain regions were observed after acupuncture intervention at uterine acupoints; the hypothalamic-pituitary system also showed various active states in different brain regions. It is speculated that the effective mechanism of acupuncture at uterine acupoints is related to the regulation of reproductive hormones, emotional changes, and somatic sensations. Therefore, the methods used in this study could clarify the neural mechanism of uterine-point acupuncture in the treatment of gynecological diseases and may serve as a reference for other studies pertaining to acupuncture.