Temporal Unfolding of Racial Ingroup Bias in Neural Responses to Perceived Dynamic Pain in Others / 神经科学通报·英文版

In this study, we investigated how empathic neural responses unfold over time in different empathy networks when viewing same-race and other-race individuals in dynamic painful conditions. We recorded magnetoencephalography signals from Chinese adults when viewing video clips showing a dynamic painful (or non-painful) stimulation to Asian and White models' faces to trigger painful (or neutral) expressions. We found that perceived dynamic pain in Asian models modulated neural activities in the visual cortex at 100 ms-200 ms, in the orbitofrontal and subgenual anterior cingulate cortices at 150 ms-200 ms, in the anterior cingulate cortex around 250 ms-350 ms, and in the temporoparietal junction and middle temporal gyrus around 600 ms after video onset. Perceived dynamic pain in White models modulated activities in the visual, anterior cingulate, and primary sensory cortices after 500 ms. Our findings unraveled earlier dynamic activities in multiple neural circuits in response to same-race (vs other-race) individuals in dynamic painful situations.

Abnormal gray matter volume of MRI in the somatic symptoms of depression / 中国神经精神疾病杂志

Objective To explore specific magnetic resonance imaging(MRI)features of somatic symptoms in depression by comparing the differences of brain gray matter volume in depression patients with and without somatic symptoms using voxel-based morphometry(VBM).Methods A total of 52 depression patients were recruited and divided into somatic and no somatic symptoms group according to the patient health questionnaire-15 score(＞9 and≤9,respectively).Forty gender-age-matched healthy volunteers were recruited as the control group.All subjects underwent MRI scanning.Imaging data were analyzed to explore the differences in brain gray matter between groups using VBM.Results Compared with control group,gray matter volume increased in the right superior temporal gyrus,and decreased in the right inferior orbitofrontal gyrus,right inferior temporal gyrus,left inferior orbitofrontal gyrus,and left superior temporal gyrus for depressive patients with somatic symptoms(P＜0.001);gray matter volume increased in the right middle temporal gyrus,and decreased in the right superior temporal gyrus and right inferior temporal gyrus for depressive patients without somatic symptoms(P＜0.001).Only the volume in the right tongue and left cingulate gyrus increased in depressive patients with somatic symptoms compared with that in patients without somatic symptoms(P＜0.01).Conclusion VBM-MRI has demonstrated increased volume in the tongue and cingulate gyrus in the somatic symptoms of depression.

An electric field modeling study with meta-analysis to understand the antidepressant effects of transcranial direct current stimulation (tDCS)

Objective: Transcranial direct current stimulation (tDCS) has mixed effects for major depressive disorder (MDD) symptoms, partially owing to large inter-experimental variability in tDCS protocols and their correlated induced electric fields (E-fields). We investigated whether the E-field strength of distinct tDCS parameters was associated with antidepressant effect. Methods: A meta-analysis was performed with placebo-controlled clinical trials of tDCS enrolling MDD patients. PubMed, EMBASE, and Web of Science were searched from inception to March 10, 2023. Effect sizes of tDCS protocols were correlated with E-field simulations (SimNIBS) of brain regions of interest (bilateral dorsolateral prefrontal cortex [DLPFC] and bilateral subgenual anterior cingulate cortex [sgACC]). Moderators of tDCS responses were also investigated. Results: A total of 20 studies were included (21 datasets, 1,008 patients), using 11 distinct tDCS protocols. Results revealed a moderate effect for MDD (g = 0.41, 95%CI 0.18-0.64), while cathode position and treatment strategy were found to be moderators of response. A negative association between effect size and tDCS-induced E-field magnitude was seen, with stronger E-fields in the right frontal and medial parts of the DLPFC (targeted by the cathode) leading to smaller effects. No association was found for the left DLPFC and the bilateral sgACC. An optimized tDCS protocol is proposed. Conclusions: Our results highlight the need for a standardized tDCS protocol in MDD clinical trials. Registration number: PROSPERO CRD42022296246.

Mechanism of anterior cingulate cortex in modulating pain and anxiety-like behavior in chronic non-specific low back pain model rats / 中华行为医学与脑科学杂志

Objective:To explore the potential mechanisms of anterior cingulate cortex (ACC) in modulating pain behavior and anxiety-like behavior of rats with chronic non-specific low back pain induced by nerve growth factor (NGF).Methods:Ninety-six male SPF grade SD rats aged 8 weeks were randomly divided into four groups according the random number table method: control group, model group, control+ D-2-amino-5-phosphonopentanoate (D-AP5) group (control+ D-AP5 group) and model+ D-AP5 group, with 24 rats in each group.Low back pain model of rat was established by injection of NGF into multifidus muscle (left side) of the low backs of rats(two times with a five-day interval). Five days after modeling, rats in model+ D-AP5 group and control+ D-AP5 group were injected with the N-methyl-D-aspartate (NMDA) receptor antagonist D-AP5(2 μg, 0.3 μL) at the right side of the ACC once a day for consecutive 3 days, and rats in control group and model group were injected with the same amount of 0.9% sodium chloride solution. Seven days after modeling, the pain threshold of rats was evaluated by mechanical stimulation test and hot and cold plate test.The anxiety-like behavior was tested by open field test.The density of glial fibrillary acidic protein (GFAP) positive cells and c-Fos(a kind of immediate early gene) positive cells of the spinal cord were observed by immunofluorescence. The expression of GFAP, c-Fos, phosphorylated-c-Jun N-terminal kinases (p-JNK), monocyte chemoattractant protein-1 (MCP-1), and chemokine (C-X-C motif) ligand 1 (CXCL-1) proteins in the L2 segment of the spinal cord were detected by Western blot. SPSS 23.0 software was used for statistical analysis. One-way ANOVA was used to analyze normal distribution measurement data for comparison among multiple groups, and Tukey test was used for further pairwise comparisons. The Kruakal-Wallis H test was used for non-normal distribution measurement data, and Mann-Whitney U test was used for further pairwise comparisons with Bonferroni-corrected P-values. Results:In the experiments measuring pressure pain threshold (PPT) and paw withdrawal threshold (PWT), there were statistically significant differences in the PPT and PWT of rats among the four groups ( F=53.498, 41.939, both P<0.001). Seven days after modeling, PPT ((418.5±46.9) g) and PWT ( (55.6±7.1) g) in the ipsilateral side of the rats in model+ D-AP5 group were higher than those in model group ((290.0±32.0) g, (30.5±7.5) g) (both P<0.001). In the open field test, there were statistically significant differences in percentage of the inner zone distance ( H=11.922, P<0.01) and the percentage of inner zone time ( H=21.614, P<0.001) of rats among the four groups. The percentage of inner zone time in model+ D-AP5 group was higher than that in model group (5.6(4.3, 7.9) %, 3.1(2.1, 3.8) %) ( P<0.01). The results of immunofluorescence showed that there were statistically significant differences in the density of GFAP positive cells and c-Fos positive cells at the ipsilateral side of the superficial laminae of rats among the four groups ( H=49.085, F=18.120, both P<0.001). The density of GFAP positive cells (34.3(21.1, 47.5) cells/mm 2) and c-Fos positive cells ((52.7±39.4) cells/mm 2) at the ipsilateral side of the superficial laminae in model+ D-AP5 group were less than those in model group (76.5(68.6, 94.9) cells/mm 2, (112.4±63.7) cells/mm 2) (both P<0.001). The Western blot results showed that there were statistically significant differences in the protein expression of GFAP, c-Fos, p-JNK, MCP-1 and CXCL-1 in the L2 segment of rats among the four groups ( F=49.413, 38.437, 41.867, 36.735, 130.951, all P<0.001). The protein expression of GFAP (1.7±0.5), c-Fos (1.1±0.1), p-JNK (1.7±0.3), MCP-1 (1.0±0.4) and CXCL-1 (0.8±0.1) in the L2 segment in model+ D-AP5 group were lower than those in model group ((4.3±0.7), (2.6±0.5), (2.8±0.4), (2.9±0.4), (3.5±0.4)) (all P<0.01). Conclusion:ACC modulates mechanical hyperalgesia and anxiety-like behavior in chronic non-specific low back pain rats, which might be associated with the involvement of spinal astrocytes, p-JNK signal pathway and chemokines such as MCP-1 and CXCL-1.

N-methyl-D-aspartic acid receptor/MAPK/cAMP-response element binding protein pathway mediating pain-related aversion in anterior cingulate cortex / 解剖学报

Objective To explore the mechanism of N-methyl-D-aspartic acid ( NMDA) receptor/MAPK/cAMPresponse element binding protein ( CREB) pathway involved in pain-related aversion mediated by anterior cingulate cortex. Methods A total of 42 healtlry SD rats were randomly divided into control group (Ctrl) , normal saline(NS) injection group (NS) , complete freund adjuvant (CFA) model group ( CFA ) , injected CFA into the soles of the foot and injected NS into rostral part of anterior cingulate cortex (rACC)group (CFA+NS) , injected NS into the soles of the foot and injected NS into rACC group (NS+NS) , injected CFA into the soles of the foot and injected NMDA receptor antagonist ( APV ) into rACC group (CFA+APV) , injected NS into the soles of the foot and injected APV into rACC group ( NS + APV ) with 6 rats in each group. Rats avoidance score was analysised and rat thermal foot contraction latency ( PWL) ws alserved, the expression of NMDA receptor in rACC region was detected by immunohistochemical staining, the expression of NMDA receptor, phosphorylated ERK( p-ERK) and phosphorylated CREB ( p - CREB ) in rACC region was detected by immunofluorescent staining, the number of Nissl bodies in rACC region was observed by Nissl staining, and the expression of NMDA receptor, MAPK, CREB, ERK, p-ERK, p-CREB, synaptosomal-associated protein 25 interaction protein 30 (SIP30) protein in rACCregion was detected by Western blotting, and Real-time PCR was used to detect the mRNA expression of NMDA receptor, MAPK, CREB and ERK in the rACC region. Results Compared with the Ctrl group, the avoidance score and PWL decreased significantly and the expression of NMDA receptor, MAPK and CREB increased significantly in the CFA group (P<0. 05). Compared with the CFA+NS group, the number of Nissl bodies in CFA+APV and NS+APV groups increased significantly, while the expression of NMDA receptor, MAPK, CREB, p-ERK and p-CREB decreased significantly in NS+NS and NS+APV groups (P<0. 05). Conclusion NMDA receptor-MAPK-CREB signal pathway in rACC is involved in painrelated aversion, and inhibition of NMDA can reduce pain-related negative aversion.

An Anterior Cingulate Cortex-to-Midbrain Projection Controls Chronic Itch in Mice / 神经科学通报·英文版

Itch is an unpleasant sensation that provokes the desire to scratch. While acute itch serves as a protective system to warn the body of external irritating agents, chronic itch is a debilitating but poorly-treated clinical disease leading to repetitive scratching and skin lesions. However, the neural mechanisms underlying the pathophysiology of chronic itch remain mysterious. Here, we identified a cell type-dependent role of the anterior cingulate cortex (ACC) in controlling chronic itch-related excessive scratching behaviors in mice. Moreover, we delineated a neural circuit originating from excitatory neurons of the ACC to the ventral tegmental area (VTA) that was critically involved in chronic itch. Furthermore, we demonstrate that the ACC→VTA circuit also selectively modulated histaminergic acute itch. Finally, the ACC neurons were shown to predominantly innervate the non-dopaminergic neurons of the VTA. Taken together, our findings uncover a cortex-midbrain circuit for chronic itch-evoked scratching behaviors and shed novel insights on therapeutic intervention.

Morphological study on abnormal brain development induced by hypoxia in neonatal mice / 神经解剖学杂志

Objective:Neonatal mice hypoxia model was established to observe the responses of the main neural cell types in cognition-related brain areas.Methods:Pups at postnatal day 2(P2)were subjected to 10％oxygen for suc-ceeding 5 days,and harvested at different development stage for histologic study.Immunofluorescence histochemistry was used to compare the changes of oligodendrocyte density,mature oligodendrocyte ratio and myelin protein level in corpus callosum(CC)and motor cortex(M1)after hypoxia,as well as the expression changes of excitatory and inhibi-tory neurons in anterior cingulate cortex(ACC),hippocampus(Hippo)and sensory cortex(S1).Furthermore,the density changes of different types of inhibitory intermediate neurons,microglia and astrocytes in ACC were compared.At the same time,the effect of hypoxia on the expression of synaptic proteins was also detected.Results:Quantitative immunofluorescence results showed lower myelin protein levels and mature oligodendrocyte ratio in CC and M1 of hypoxic mice compared with control mice.There was no significant difference in the number of excitatory neurons in ACC,but the number of gamma-aminobutyric acid(GABA)neurons in ACC,Hippo,and S1 were significantly reduced,especially parvalbumin neuron,ssomatostatin neurons,and vasoactive intestinal polypeptide neurons in ACC.The number of excitatory synapses labeled by vesicular glutamate transporter 1(VGluT1)and inhibitory synapses labeled by gephyrin were significantly decreased in ACC of hypoxic mice.Although there was no significant difference in astrocyte and microglia numbers,microglia were activated after hypoxic injury.Conclusion:Chronic hypoxia will lead to changes in the development of oligodendrocytes and interneurons,impair synapse formation.These results provide an important experimental basis for exploring the neural mechanism of diseases related to abnormal brain intelligence devel-opment.

Astragalin induces autophagy of astrocytes in anterior cingulate cortex of inflammatory pain mice / 中国病理生理杂志

AIM:To investigate the effects of astragalin(AST)on activation status of astrocytes and the ex-pression level of autophagy-related proteins in the cortex of the anterior cingulate cortex of mice with a complete Freund's adjuvant(CFA)-induced inflammatory pain model.METHODS:Twenty-four 6-month-old male C57BL/6 mice were ran-domly divided into four groups:control group,saline group,CFA model group and CFA+60 mg/kg AST administration group,and six mice in each group.Mice in the AST administration group received 60 mg/kg AST by intraperitoneal injec-tion on a body weight basis for 21 d.The paw withdrawal threshold in each group of mice was evaluated by the von Frey test.The expression levels of autophagy-related factors LC3,p62,ATG12 and beclin-1,and astrocyte activation were de-tected by multiplex immunofluorescence staining in the anterior cingulate cortex of mice in each group.Western blot was used to measure the levels of autophagy-related proteins LC3,p62,ATG12 and beclin-1 in the anterior cingulate cortex of mice in each group.RESULTS:Behavioural tests showed that AST significantly increased mechanical pain thresholds in CFA mice(P＜0.05).The results from multiple immunofluorescent staining showed that AST significantly increased the fluorescence intensity of LC3(P＜0.01),ATG12(P＜0.01)and beclin-1(P＜0.05),attenuated the fluorescence intensi-ty of p62(P＜0.05),and inhibited the activation of astrocytes in the anterior cingulate cortex of CFA mice.Western blot results further confirmed that AST significantly increased the expressions of LC3(P＜0.01),ATG12(P＜0.01),beclin-1(P＜0.01),and decreased the expression of p62(P＜0.05)in the anterior cingulate cortex of CFA mice.CONCLU-SION:AST relieves CFA-induced inflammatory pain of mice,and its analgesic mechanism may be related to the inhibi-tion of activation of cortical astrocytes in the anterior cingulate cortex and the promotion of autophagy in CFA mice.

Clinical effectiveness and its mechanisms of deep brain stimulation in treatment-resistant depressive disor-ders / 中国神经精神疾病杂志

Deep brain electrical stimulation is one of the emerging therapeutic approaches for treatment-resistant depressive disorders.This article outlines a variety of potential targets for deep brain electrical stimulation in the treatment of treatment-resistant depressive disorders and summarizes the results of relevant clinical studies.These targets include the subgenual cingulate gyrus,nucleus accumbens,ventral capsule and ventral striatum area,medial forebrain bundle,and lateral habenula,among other regions.Based on these studies,the article integrates relevant basic research and further discusses the possible mechanisms through which deep brain stimulation may exert therapeutic effects,including synaptic plasticity,neurophysiology,neural circuits,and neurotransmitters.The article also assesses and prospects the further application potential of deep brain electrical stimulation.The authors believe that the multi-target stimulation combining existing clinical research results and neurobiological mechanisms could be a crucial development direction to enhance the treatment of treatment-resistant depressive disorders using deep brain electrical stimulation.

A narrative review on invasive brain stimulation for treatment-resistant depression

While most patients with depression respond to pharmacotherapy and psychotherapy, about one-third will present treatment resistance to these interventions. For patients with treatment-resistant depression (TRD), invasive neurostimulation therapies such as vagus nerve stimulation, deep brain stimulation, and epidural cortical stimulation may be considered. We performed a narrative review of the published literature to identify papers discussing clinical studies with invasive neurostimulation therapies for TRD. After a database search and title and abstract screening, relevant English-language articles were analyzed. Vagus nerve stimulation, approved by the U.S. Food and Drug Administration as a TRD treatment, may take several months to show therapeutic benefits, and the average response rate varies from 15.2-83%. Deep brain stimulation studies have shown encouraging results, including rapid response rates (> 30%), despite conflicting findings from randomized controlled trials. Several brain regions, such as the subcallosal-cingulate gyrus, nucleus accumbens, ventral capsule/ventral striatum, anterior limb of the internal capsule, medial-forebrain bundle, lateral habenula, inferior-thalamic peduncle, and the bed-nucleus of the stria terminalis have been identified as key targets for TRD management. Epidural cortical stimulation, an invasive intervention with few reported cases, showed positive results (40-60% response), although more extensive trials are needed to confirm its potential in patients with TRD.

Anterior Cingulate Cortex Mediates Hyperalgesia and Anxiety Induced by Chronic Pancreatitis in Rats / 神经科学通报·英文版

Central sensitization is essential in maintaining chronic pain induced by chronic pancreatitis (CP), but cortical modulation of painful CP remains elusive. Here, we examined the role of the anterior cingulate cortex (ACC) in the pathogenesis of abdominal hyperalgesia in a rat model of CP induced by intraductal administration of trinitrobenzene sulfonic acid (TNBS). TNBS treatment resulted in long-term abdominal hyperalgesia and anxiety in rats. Morphological data indicated that painful CP induced a significant increase in FOS-expressing neurons in the nucleus tractus solitarii (NTS) and ACC, and some FOS-expressing neurons in the NTS projected to the ACC. In addition, a larger portion of ascending fibers from the NTS innervated pyramidal neurons, the neural subpopulation primarily expressing FOS under the condition of painful CP, rather than GABAergic neurons within the ACC. CP rats showed increased expression of vesicular glutamate transporter 1, and increased membrane trafficking and phosphorylation of the N-methyl-D-aspartate receptor (NMDAR) subunit NR2B and the α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR) subunit GluR1 within the ACC. Microinjection of NMDAR and AMPAR antagonists into the ACC to block excitatory synaptic transmission significantly attenuated abdominal hyperalgesia in CP rats, which was similar to the analgesic effect of endomorphins injected into the ACC. Specifically inhibiting the excitability of ACC pyramidal cells via chemogenetics reduced both hyperalgesia and comorbid anxiety, whereas activating these neurons via optogenetics failed to aggravate hyperalgesia and anxiety in CP rats. Taken together, these findings provide neurocircuit, biochemical, and behavioral evidence for involvement of the ACC in hyperalgesia and anxiety in CP rats, as well as novel insights into the cortical modulation of painful CP, and highlights the ACC as a potential target for neuromodulatory interventions in the treatment of painful CP.

To Blame or Not? Modulating Third-Party Punishment with the Framing Effect / 神经科学通报·英文版

People as third-party observers, without direct self-interest, may punish norm violators to maintain social norms. However, third-party judgment and the follow-up punishment might be susceptible to the way we frame (i.e., verbally describe) a norm violation. We conducted a behavioral and a neuroimaging experiment to investigate the above phenomenon, which we call the "third-party framing effect". In these experiments, participants observed an anonymous perpetrator deciding whether to keep her/his economic benefit while exposing a victim to a risk of physical pain (described as "harming others" in one condition and "not helping others" in the other condition), then they had a chance to punish that perpetrator at their own cost. Our results showed that the participants were more willing to execute third-party punishment under the harm frame compared to the help frame, manifesting a framing effect. Self-reported anger toward perpetrators mediated the relationship between empathy toward victims and the framing effect. Meanwhile, activation of the insula mediated the relationship between mid-cingulate cortex activation and the framing effect; the functional connectivity between these regions significantly predicted the size of the framing effect. These findings shed light on the psychological and neural mechanisms of the third-party framing effect.

Modulation of transcutaneous auricular vagus nerve stimulation on default mode network in patients with primary insomnia / 中国针灸

OBJECTIVE@#To explore the modulation of transcutaneous auricular vagus nerve stimulation (taVNS) on default mode network (DMN) in patients with primary insomnia (PI).@*METHODS@#A total of 22 PI patients (one patient dropped off and two patients were excluded) were included and treated with taVNS. The bilateral auricular points of Xin (CO15) and Shen (CO10) were selected and treated with disperse-dense wave at frequency of 4 Hz/20 Hz, the intensity was based on the patient's tolerance. taVNS was given once in the morning and once in the evening for 30 minutes each time. The treatment lasted for at least 5 days a week for 4 weeks. At the same time, 16 healthy subjects matched with gender and age were recruited. The Pittsburgh sleep quality index (PSQI) score was evaluated before and after treatment in PI patients. The resting-state functional magnetic resonance imaging (rs-fMRI) data of PI patients before and after treatment and healthy subjects at baseline period were collected to observe the effect of taVNS on the functional connection (FC) between posterior cingulate cortex (PCC) and whole brain.@*RESULTS@#After treatment, the total score of PSQI in PI patients was lower than that before treatment (P<0.01). Compared with healthy subjects, the FC of the left PCC was increased either with the left orbital superior frontal gyrus or with left middle frontal gyrus (P<0.001), and the FC between right PCC and left middle frontal gyrus was increased in PI patients before treatment (P<0.001). Compared before treatment, the FC between left PCC and left middle frontal gyrus was decreased (P<0.05), and the FC of the right PCC was decreased either with the right medial prefrontal cortex or with the left middle frontal gyrus in PI patients after treatment (P<0.001, P<0.01).@*CONCLUSION@#taVNS can modulate the FC between anterior and posterior DMN, and between DMN and cognitive control network of PI patients, which may be one of the brain effect mechanisms of taVNS in the treatment of PI patients.

Efficacy and possible mechanism study of low-intensity focused ultrasound therapy for neuropathic pain in mice / 中华超声影像学杂志

Objective:To study the efficacy of low-intensity focused ultrasound (LIFU) on neuropathic pain (NP) in mice, and its effect on the activation of astrocytes and the expression of pro-inflammatory cytokines were discussed.Methods:Thirty-six male C57BL/6J mice were randomly divided into three groups: sham operation (Sham) group and chroinc constriction injury (CCI) model group and treatment (CCI+ LIFU) group, 12 mice in each group.NP model was established by CCI on the sciatic nerve. The group of CCI+ LIFU received LIFU treatment for the anterior cingulate cortex (ACC) on the 7th day after surgery, the mechanical withdrawal threshold (MWT) on the affected side of mice was measured at preoperation 3, 6, 12, 18, 24, and 27 days after operation, respectively, H&E staining was used to observe pathological morphological changes in the ACC region, the expression levels of ACC region AQP4 and GFAP protein were detected by Western Blot and immunofluorescence, and the expression levels of ACC region pro-inflammatory cytokines IL-1β and TNF-α were detected by enzyme-linked immunosorption assay.Results:Compared with Sham group, MWT in the CCI group decreased from the 3rd day until the 27th day after surgery( P<0.05); Compared with the CCI group, the MWT in the CCI+ LIFU group increased on the 24th day after surgery, and was significantly higher than that of the CCI group on the 24th and 27th day after surgery ( P<0.05); LIFU stimulation did not produce significant pathological changes in the ACC region; Western Blot and immunofluorescence showed that AQP4 and GFAP protein expression in the ACC region were upregulated ( P<0.05) after peripheral nerve injury, while AQP4 and GFAP protein expression was downregulated after LIFU treatment ( P<0.05); Enzyme-linked immunosorbents showed that the expression of pro-inflammatory cytokines IL-1β and TNF-α in the region of ACC was upregulated ( P<0.05) after peripheral nerve injury, while the expression of IL-1β and TNF-α was downregulated after LIFU treatment ( P<0.05). Conclusions:LIFU can effectively relieve mechanical pain sensitivity symptoms in mice induced by CCI, possibly by inhibiting activation of astrocytes and neuro-inflammatory responses.

Cerebral Responses to Stationary Emotional Stimuli Measured by fMRI in Women with Persistent Postural-Perceptual Dizziness

Abstract Introduction Persistent postural-perceptual dizziness (PPPD) is a functional vestibular disorder characterized by chronic dizziness, unsteadiness, and hypersensitivity to motion. Preexisting anxiety disorders and neurotic personality traits confer vulnerability to PPPD. High anxiety during acute vertigo or dizziness incites it. A functional magnetic resonance imaging (fMRI) study of chronic subjective dizziness found unexpectedly hypoactive responses to vestibular stimulation in cortical regions that integrate threat assessment and spatial perception. Objective This fMRI study used non-moving, but emotionally charged visual stimuli to investigate the brain's activity of PPPD patients and control subjects. Methods The participants included 16 women with PPPD and 16 age-matched women who recovered completely from acute episodes of vertigo or dizziness capable of triggering PPPD. Brain responses to positive, neutral, and negative figures from the International Affective Picture System were measured with fMRI and compared between the groups. Dizziness handicap, anxiety, and depression were assessed with validated questionnaires. Results Between group analyses: Participants with PPPD showed reduced activity in anterior cingulate cortex and increased activity in left angular gyrus in response to negative versus positive stimuli, which was not observed in recovered individuals. Within group analyses: Participants with PPPD had increased activity in visuospatial areas (parahippocampal gyrus, intraparietal sulcus) in negative versus positive and negative versus neutral contrasts, whereas recovered individuals had increased activity in anxiety regions (amygdala, orbitofrontal cortex). Conclusion Patients with PPPD may be more attuned to spatial elements than to the content of emotionally charged visual stimuli.

The predicting effect of disrupted functional connectivity of anterior cingulate cortex on the efficacy of nonsteroidal anti-inflammatory drugs in migraineurs without aura / 中华行为医学与脑科学杂志

Objective:To investigate the predicting effect of the disrupted functional connectivity of the anterior cingulate cortex (ACC) on the efficacy of non-steroidal anti-inflammatory drugs (NSAIDs) in patients with migraineurs without aura (MwoA).Methods:From January 2019 to January 2021, seventy patients with migraine and thirty-three healthy people in the same period were selected.The functional connectivity analysis based on the ACC was used in MwoA patients with NSAIDS-effective ( n=35), MwoA patients with NSAIDS-ineffective ( n=35), and healthy controls (HCs) ( n=33). The abnormal resting-state functional connectivity patterns among the three groups were analyzed to reveal potential correlations with clinical characteristics in migraine. Then the receiver operating characteristic (ROC) curve was used to analyze the predictive ability of the abnormal ACC functional connectivity on the efficacy of NSAIDs in patients with MwoA. Results:(1)Compared with the MwoA patients with NSAIDs-ineffective, the MwoA patients with NSAIDs-effective showed higher functional connectivity between bilateral ACC and left middle cingulate cortex (MCC) (MNI: x, y, z=0, -24, 48, cluster=14, t=3.380) and postcentral gyrus (PoCG)( MNI: x, y, z=-21, -45, 69, cluster=12, t=3.016) (all P<0.005, Bonferroni correction). Compared with the HCs, patients with MwoA showed increased functional connectivity between left ACC and ipsilateral inferior parietal lobule, middle frontal gyrus (MFG) and angular gyrus (AG), and between right ACC and right precuneus, bilateral MFG and left AG (all P<0.005, Bonferroni correction). (2)There was a positive correlation between the functional connectivity of right ACC to right precuneus and MIDAS scores ( r=0.375, P=0.035) in MwoA patients with NSAIDs-effective. In MwoA patients with NSAIDs-ineffective, there were also significant correlations between the functional connectivity of left ACC to ipsilateral AG and MFG and headache onset duration ( r=0.357, P=0.045) and disease duration ( r=-0.367, P=0.039). (3)ROC curve analysis showed that the area under the curve (AUC) for the functional connectivity between the right ACC and left MCC and between the left ACC and left PoCG to predict the efficacy of NSAIDs were 0.728 and 0.736, respectively. Conclusions:Resting-state functional connectivity of the ACC is involved in the evaluation and prediction for analgesic efficacy of NSAIDs in migraine patients, which provides neuroimaging evidence for further investigations on the neurophysiological mechanism of migraine and assistance in clinical individualized precise treatment.

Role of the Anterior Cingulate Cortex in Translational Pain Research / 神经科学通报·英文版

As the most common symptomatic reason to seek medical consultation, pain is a complex experience that has been classified into different categories and stages. In pain processing, noxious stimuli may activate the anterior cingulate cortex (ACC). But the function of ACC in the different pain conditions is not well discussed. In this review, we elaborate the commonalities and differences from accumulated evidence by a variety of pain assays for physiological pain and pathological pain including inflammatory pain, neuropathic pain, and cancer pain in the ACC, and discuss the cellular receptors and signaling molecules from animal studies. We further summarize the ACC as a new central neuromodulation target for invasive and non-invasive stimulation techniques in clinical pain management. The comprehensive understanding of pain processing in the ACC may lead to bridging the gap in translational research between basic and clinical studies and to develop new therapies.

Mechanism of Chuanxiong Rhizoma intervention on central sensitization of Panx1-Src-NMDAR-2B signaling pathway in neuropathic pain model rats / 中国中药杂志

Excitatory toxicity(ET) is an important factor of neuropathic pain(NPP) induced by central sensitization(CS), and the association of pannexin-1(Panx1)-Src-N-methyl-D-aspartate receptor subunit 2 B(NMDAR-2 B) is an important new pathway for ET to initiate CS. The present study confirmed whether the central analgesic effect of Chuanxiong Rhizoma extract(CRE) was achieved through the synchronous regulation of the brain and spinal pathways of Panx1-Src-NMDAR-2 B. In this study, dynamic and simulta-neo-us microdialysis of the brain and spinal cord in vivo combined with behavioristics, high performance liquid chromatography(HPLC)-fluorescence detection, microdialysis analysis(ISCUS~(flex)), ultrasensitive multifactorial electrochemiluminescence immunoassay, ELISA, and Western blot was employed to investigate the protein expression of NMDAR-2 B, Src, and Panx1, extracellular excitatory amino acids, cytokines, energy metabolites, and substance P in spinal dorsal horn(SDH) and anterior cingulate cortex(ACC) after CRE intervention with the rat model of spared sciatic nerve injury(SNI) as the experimental tool. Compared with the sham group, the SNI group exhibited diminished mechanical withdrawal threshold(MWT)(P<0.01), increased cold spray scores(P<0.01), glutamate(Glu), D-serine(D-Ser), and glycine(Gly) in extracellular fluids of ACC, and Glu, D-Ser, interleukin-1β(IL-1β), and lactic acid(Lac) in extracellular fluids of SDH(P<0.05), dwindled tumor necrosis factor(TNF-α)(P<0.05), and elevated protein levels of NMDAR-2 B, Src, and Panx1 in ACC(P<0.05). Compared with the SNI model rats, high-and medium-dose CRE(CRE-H/M) could potentiate the analgesic activity as revealed by the MWT test(P<0.05) and CRE-M enabled the decrease in cold spray scores(P<0.05). CRE-H/M could inhibit the levels of Glu, D-Ser and Gly in the extracellular fluids of ACC(P<0.05), and the levels of Glu in the extracellular fluids of SDH(P<0.05) in SNI rats. CRE-M significantly increased the levels of glucose(Gluc), Lac, interferon-gamma(IFN-γ), keratinocyte chemoattractant/human growth-regulated oncogenes(KC/GRO), and IL-4 in extracellular fluids of SDH in SNI rats(P<0.05). CRE-H/M/L could also inhibit the levels of NMDAR-2 B, Src and Panx1 in ACC and SDH in SNI rats(P<0.05). The central analgesic effect of CRE is presumedly related to the inhibited release of excitatory amino acid transmitters(Glu, D-Ser and Gly) in ACC and SDH of SNI rats, decreased protein expression of NMDAR-2 B, Src and Panx1 in the two regions, and the regulation of the Panx1-Src-NMDAR-2 B pathway in the spinal cord and brain. The above findings partially clarified the scientific basis of clinical analgesic effect of Chuanxiong Rhizoma.

Chemokine CCL21 in anterior cingulate cortex is involved in chronic neuropathic pain in a rat model / 中国组织工程研究

BACKGROUND: The pathogenesis of chronic pathological pain is yet unknown. Some studies have shown that after spinal cord injury, CCL21 can activate microglia in the central nervous system and is expressed only in damaged neurons, promoting the formation of chronic pathological pain. OBJECTIVE: To investigate whether the anterior cingulate cortex is involved in the formation of chronic pathological pain after inferior orbital nerve ligation in rats, and whether blocking chemokine CCL21 in the anterior cingulate cortex can reduce the chronic neuropathic pain. METHODS: A total of 80 male Sprague-Dawley rats were randomly divided into 4 groups with 20 rats in each group. In the sham group, only the infraorbital nerve of the rats was exposed; in the model group, the left infraorbital nerve was ligated; in the anti-CCL21 group, CCL21 neutralizing antibodies was administered to the anterior cingulate cortex of the rats on the 7th day after surgery; and in the PBS control group, PBS solution was given into the anterior cingulate cortex of rats on the 7th day after surgery. Rats in the sham and model groups were subjected to behavioral tests on the 3rd, 5th, 7th, and 14th days after surgery, and those in the anti-CCL21 and PBS control groups were subjected to the behavioral test at 6 hours after administration. All rats were sacrificed under anesthesia after behavioral tests. The cortical tissues were taken from the anterior cingulate, and the protein content of CCL21 was determined by western blot and immunofluorescence. RESULTS AND CONCLUSION: The pain threshold of the rats in the model group was lower than that in the sham group, and the expression of CCL21 in the anterior cingulate cortex was significantly higher in the model group than the sham group. After the administration of CCL21 neutralizing antibody, the expression of CCL21 was reduced to some extents, and the rat pain threshold was increased accordingly. These findings reveal that the anterior cingulate cortex of rats may be involved in the production of chronic pathological pain, and the administration of CCL21 neutralizing antibody can relief the pain.

Recent advance in relation between functional anatomy of cingulate gyrus and epilepsy symptom of cingulate gyrus / 中华神经医学杂志

The cingulate gyrus is an important part of the limbic system. According to anatomical position, it can be divided into anterior cingulate cortex, middle cingulate cortex and posterior cingulate cortex. The functional anatomy characteristics of cingulate gyrus are closely related to epilepsy symptoms of the cingulate. Therefore, the study summarizes the anatomical function, seizure symptoms and electrical stimulation results of cingulate gyrus, in order to provide help for the diagnosis of cingulate gyrus epilepsy.