Gaining insight into the neural basis of resting-state fMRI signalThe blood oxygenation level-dependent (BOLD)-based resting-state functional magnetic resonance imaging (rsfMRI) has been widely used as a non-invasive tool to map brain-wide connectivity architecture. However, the neural basis underpinning the resting-state BOLD signal remains elusive. In this study, we combined simultaneous calcium-based fiber photometry with rsfMRI in awake animals to examine the relationship of the BOLD signal and spiking activity at the resting state. We observed robust couplings between calcium and BOLD signals in the dorsal hippocampus as well as other distributed areas in the default mode network (DMN), suggesting that the calcium measurement can reliably predict the rsfMRI signal. In addition, using the calcium signal recorded as the ground truth, we assessed the impacts of different rsfMRI data preprocessing pipelines on functional connectivity mapping. Overall, our results provide important evidence suggesting that spiking activity measured by the calcium signal plays a key role in the neural mechanism of resting-state BOLD signal.
Long-duration general anesthesia influences the intelligence of school age childrenBACKGROUND: General anesthesia has been linked to impaired brain development in immature animals and young children. In this study the influence of orthopedic surgery under general anesthesia on the intelligence of school age children has been evaluated. METHODS: A total of 209 subjects aged 6-12 years were recruited and allocated into 4 groups according to the duration of general anesthesia, including a control group (n = 30), short (< 1 h, n = 49), moderate- (1-3 h, n = 51) and long-duration groups (> 3 h, n = 79), respectively. The intelligence quotient (IQ) of the subjects was measured by the Raven's Standard Progressive Matrices (RSPM) before and after orthopedic surgery under general anesthesia of various durations (vide supra). RESULTS: The IQ score decreased significantly in the long-duration group at 1 month post-operation compared with the pre-operation score (P < 0.001), and IQ did not recover completely at 3 months postoperatively (P < 0.05), but had recovered when measured at the 1-year follow-up. Moreover, this study showed that the development of children's intelligence was affected by the exposure time to anesthetics at a younger age (OR = 5.26, 95% CI:2.70-8.41, P < 0.001), having a mother with a low education level (OR = 2.71, 95% CI:1.24-6.14, P = 0.014) and premature birth (OR = 2.76, 95% CI:1.34-5.46, P = 0.005). CONCLUSIONS: More than 3 h general anesthesia influenced the IQ of school age children for up to 3 months after orthopedic surgery. Beside extended exposure time to anesthetics additional factors for post-operative IQ reduction were younger children age, mothers with low educational levels and premature birth. TRIAL REGISTRATION: Chinese Clinical Trial Registry with registration number ChiCTR-OOC-17013497 retrospectively registered on 11/23/2017.
Research progress of plant‐derived natural alkaloids in central nervous system diseasesQingqing Zhang, Qinghua Jiang, Kuiru Sa et al.|Phytotherapy Research|2023 Central nervous system (CNS) disease is one of the most important causes of human death. Because of their complex pathogenesis, more and more attention has been paid to them. At present, drug treatment of the CNS is the main means; however, most drugs only relieve symptoms, and some have certain toxicity and side effects. Natural compounds derived from plants can provide safer and more effective alternatives. Alkaloids are common nitrogenous basic organic compounds found in nature, which exist widely in many kinds of plants and have unique application value in modern medicine. For example, Galantamine and Huperzine A from medicinal plants are widely used drugs on the market to treat Alzheimer's disease. Therefore, the main purpose of this review is to provide the available information on natural alkaloids with the activity of treating central nervous system diseases in order to explore the trends and perspectives for the further study of central nervous system drugs. In this paper, 120 alkaloids with the potential effect of treating central nervous system diseases are summarized from the aspects of sources, structure types, mechanism of action and structure-activity relationship.
Functional connectivity of the retrosplenial cortex in rats with ischemic stroke is improved by electroacupunctureQingqing Zhang, Jianhong Li, Sheng Huang et al.|Acupuncture in Medicine|2020 BACKGROUND: The aim of this study was to investigate the central mechanism underlying the putative beneficial effects of electroacupuncture (EA) on learning and memory ability of rats with ischemic stroke-induced cognitive deficits by resting-state functional magnetic resonance imaging (fMRI). METHODS: A rat model of middle cerebral artery occlusion (MCAO)-induced cognitive deficit (MICD) was established. Rats were randomly assigned into a sham-operated control group (SC group, n = 12), untreated MICD model group (MICD group, n = 12), and MICD group receiving EA treatment at GV20 and GV24 (MICD + EA group, n = 12). RESULTS: Compared to the MICD group, rats in the MICD + EA group receiving EA at GV20 and GV24 exhibited significantly shortened escape latency times and crossed the position of the platform a significantly increased number of times during the Morris water maze test on the 14th day after EA, which suggested EA could significantly improve spatial learning and memory ability. Furthermore, compared to the MICD group, functional connectivity of the left retrosplenial cortex (RSC) with the left hippocampus, left RSC, right RSC, left cingulate gyrus, right cingulate gyrus, right tegmentum of midbrain, and right visual cortex was increased in the MICD + EA group; the MICD group showed decreased functional connectivity of the left RSC with the left hippocampus, right hippocampus, left RSC, right RSC, right amygdaloid body, left visual cortex, and right visual cortex. CONCLUSION: These findings suggest that EA at GV20 and GV24 might improve the learning and memory ability of MICD rats by increasing the functional connectivity between the RSC and hippocampus, cingulate gyrus and midbrain, which is encouraging for the potential treatment for cognitive impairment secondary to ischemia stroke.
The Effect of Non-Invasive Brain Stimulation on the Downregulation of Negative Emotions: A Meta-Analysis(1) Background: Emotion regulation (ER) is regarded as a core treatment target for depression and other mental illnesses. In recent years, non-invasive brain stimulation (NIBS) has been extensively used as an intervention for mental illnesses, but there has been no systematic review conducted regarding its effect on emotion regulation. Therefore, we conducted a meta-analysis of the effectiveness of NIBS for emotion regulation; (2) Methods: Systematic searches were conducted in Embase, Web of Science, PubMed, and Cochrane Library. We analyzed the effects of NIBS on tasks assessing emotion regulation using a random-effects model, and further explored the moderating role of the following factors on transcranial direct current stimulation (tDCS) studies by conducting subgroup analyses and meta-regression: target electrode placement, return electrode placement, current intensity, target electrode size, and duration of intervention; (3) Results: A total of 17 studies were included. Our meta-analysis indicated a small but significant effect of NIBS on the downregulation of negative emotions. Separate analyses indicated that repetitive transcranial magnetic stimulation (rTMS) had a medium and significant effect on the downregulation of negative emotions, whereas tDCS had no significant effect. Subgroup analyses showed that the effect of tDCS was moderated by target and return electrode placemen; (4) Conclusions: These results indicate that NIBS had a positive effect on the downregulation of negative emotions. The stimulation protocols should be carefully considered and the underlying mechanisms should be further explored.