1.Morphological study of GABAergic neurons in the ventral zona incerta of mice involved in chronic itch
Shihao PENG ; Ze FAN ; Ziyi DAI ; Yiwen ZHANG ; Xiaotong SHI ; Yuanyuan ZHU ; Shengxi WU ; Jing HUANG
Chinese Journal of Neuroanatomy 2024;40(1):1-8
Objective:To detect itching,anxiety,depression behaviors in chronic itch models of mice and observe the activation of γ-aminobutiric acid(GABA)neurons in the ventral sector of the zona incerta(ZIv),and provide mor-phological evidence for their involvement in the modulation of itch information.Methods:Diphenylcyclopropenone(DCP)was used in glutamic acid decarboxylase 67-green fluorescent protein(GAD67-GFP)knock-in mice to establish chronic itch model.Itch behaviors were detected by video tracking system to verify whether the models were successfully established.The anxiety,depression behaviors of chronic itch model mice were detected by using elevated plus maze test(EPM)and tail suspention test(TST).By using GAD67-GFP mice,the distribution of GABAergic neurons in va-rious sectors of the zona incerta(ZI)was observed.And combined with immunofluorescence staining method,double labeling of GABAergic neurons with FOS in ZIv were observed respectively in control and DCP group mice.Results:In brain slices of GAD67-GFP mice,GABAergic neurons can be observed within all sectors of ZI and are more concentrat-ed in ZIv.Compared with control group mice,DCP group mice showed a significant increase in the bouts of scratching(P<0.001).The time of immobility in TST was significantly higher in DCP group mice than in control group mice,which displayed depression-like behavior.The EPM test showed that the numbers of entries and proportion of time in the cross region in DCP group mice were less than in control group mice.EPM test revealed that DCP group mice exhibited anxiety-like behavior.The results of immunofluorescence staining showed that the number of FOS-positive cells in ZIv was significantly higher in DCP group mice than in control group mice,and abundant co-labeled neurons of FOS and GABAergic neurons were observed in ZIv.Conclusion:GABAergic neurons were predominantly distributed in ZI,and were more concentrated in ZIv.The activation of GABAergic neurons in ZIv of DCP group mice provides morphological evidence on the involvement of GABAergic neurons in chronic itch and associated negative emotions.
2.Exercise-induced chronic fatigue impairs working memory in rats via basal ganglia output nuclei
Shuo JIN ; Hongyang LI ; Chenxuan JI ; Jinshun QI ; Lina SUN
Chinese Journal of Neuroanatomy 2024;40(1):9-15
Objective:To investigate possible neuromodulatory mechanisms involved in the involvement of parvalbu-min(PV)expression in the basal ganglia output nuclei,entopeduncular nucleus(EPN)and substantia nigra pars etic-ulata(SNr),in exercise-induced chronic fatigue impairs working memory capacity.Methods:Male SD rats were divid-ed into control group and Fatigue group by random number method,and a three-stage incremental load treadmill training program was selected to establish a chronic exhaustion exercise-induced fatigue rat model.The working memory ability of rats was assessed by the Y-maze autonomous alternation experiment.Immunohistochemical staining was used to ob-serve the expression of parvalbumin(PV)positive neurons and cysteine aspartate-specific protease-3(caspase-3)in EPN and SNr of rats.Results:The accuracy of voluntary alternation in the fatigue group was obviously lower than that in control group(P<0.05).The results of immunohistochemical staining showed that the density of PV positive neu-rons and the degree of positive fiber staining in EPN and SNr in the fatigue group were obviously lower than those in the control group(P<0.05,P<0.01).The number of caspase-3 positive cells per unit area of EPN and SNr in the fa-tigue group was obviously higher than that in the control group(P<0.05,P<0.01).Conclusion:The mechanism of impairing working memory in rats caused by exercise-induced chronic fatigue may be related to the apoptosis of PV posi-tive neurons in EPN and SNr.
3.Lycium barbarum polysaccharide inhibits starvation-induced apoptosis of Schwann cells by enhancing autophagy
Yumei LIU ; Heying WANG ; Caihong WEI ; Jinjuan WANG ; Junping LI ; Hua JIA
Chinese Journal of Neuroanatomy 2024;40(1):16-24
Objective:To investigate the inhibitory effect of lycium barbarum polysaccharide(LBP)on apoptosis of Schwann cells(SCs)and its related mechanisms.Methods:The autophagy model was prepared by starvation treatment of RSC96 cells for 12 h,and the expressions of autophagy related proteins LC3 and p62 were detected by Western Blot.Cell Counting Kit-8(CCK-8)kits were used to detect the optimal concentration of LBP.RSC96 cells were randomly divided into Control group,Starvation group and Starvation+LBP group.The expressions of autophagy associated pro-teins(LC3,p62)and myelin associated proteins(p75NTR,PMP22,S100β)were detected by Western Blot or immu-nofluorescence staining.Annexin V/PI fluorescence staining was used to detect apoptosis of the cells.The cell cycle was analyzed by flow cytometry.Western Blot analysis of phosphorylation levels of pathway proteins Erk1/2 and Akt.Results:CCK8 results showed that the viability of damaged RSC96 cells was the best when LBP was 300 μg/ml.Com-pared with Control group,LC3-Ⅱ/LC3-I levels in Starvation group were significantly increased(P<0.05).Compared with Starvation group,the proportion of apoptotic and necrotic cells in Starvation+LBP group was significantly de-creased,and the proportion of cells in S and G2/M stages was increased.The expression levels of LC3-Ⅱ,p75NTR,PMP22 and S100β were increased,while the expression levels of autophagy substrate protein p62 were decreased.In-creased expression of pathway protein p-Erk1/2(P<0.05),while the expression of p-Akt protein decreased slightly.Conclusion:LBP can inhibit the apoptosis of SCs and promote the expression of myelin-related proteins by enhancing autophagy,which is related to the activation of Erk1/2 and/or the inhibition of Akt.
4.Targeted inhibition of GABAergic neuron's DRP1 in substantia nigra pars reticulata improves motor function in mice with hepatic encephalopathy
Xiaodong LI ; Jingjing TIE ; Jinghao CHEN ; Yuze SUN ; Feifei WU ; Yanling YANG ; Yayun WANG
Chinese Journal of Neuroanatomy 2024;40(1):25-34
Objective:To investigate the effect of mitochondrial division of GABAergic neurons in substantia nigra pars reticulata(SNr)on motor dysfunction in mice with acute hepatic encephalopathy(AHE).Methods:AHE mice model was established by intraperitoneal injection of thioacetamide(TAA).The changes of liver lobules in AHE mice were observed by hematoxylin-eosin(HE)staining.The changes of serum aspartate aminotransferase(AST),alanine aminotransferase(ALT)and blood ammonia in AHE mice were detected by biochemical detection kit.Then,the motor function of AHE mice was observed by rod fatigue test,elevated cross maze test and open field test.Furthermore,the changes of mitochondrial area,perimeter,roundness and other morphological indicators in SNr of AHE mice were ob-served and analyzed by transmission electron microscopy.The expression of mitochondrial division and fusion related molecules in SNr of AHE mice was observed by Western Blot.Then,the expression of mitochondrial dynamic related protein 1(DRP1)in SNr of AHE mice was targeted by AAV virus.The mitochondrial membrane potential(MMP),ATP and reactive oxygen species(ROS)in SNr were detected by fluorescence enzyme marker,and the changes of motor function of mice were observed.Results:Compared with the control group,the motor function of AHE mice was signifi-cantly decreased,the mitochondrial division of SNr was significantly enhanced,and the expression of mitochondrial divi-sion related proteins was significantly increased.The MMP in SNr of AHE mice was significantly decreased,the ATP of cells was decreased,and the ROS was increased.After targeted inhibition of DRP1 expression in SNr of AHE mice,the movement was improved;further observation found that after the mitochondrial division in SNr of AHE mice was inhibi-ted,the MMP was significantly increased,the ATP of cells was increased,and the ROS was decreased,which demon-strated that the mitochondrial function was significantly improved.Conclusion:Targeted inhibition of mitochondrial di-vision of GABAergic neurons in SNr of AHE mice can improve mitochondrial morphology and function,thus alleviating their movement disorders.
5.FOS expression in oxytocin and vasopressin positive neurons in paraventricular nucleus of mice induced by diabetes
Shumin WANG ; Peng JIA ; Shuting REN ; Siting LYU ; Ting ZHANG ; Yanling YANG ; Juan SHI
Chinese Journal of Neuroanatomy 2024;40(1):35-42
Objective:To explore the feature of FOS expression in oxytocin-and vasopressin-positive neurons in the hypothalamic paraventricular nucleus(PVN)under different status of diabetes mellitus(DM).Methods:Intraperito-neal injection of vehicle or STZ in mice was conducted to establish control or diabetes model.Mechanical sensitivity was evaluated by von Frey filament tests to distinguish diabetic neuropathic pain(DNP)from without-pain group(DWP).The expression of FOS,oxytocin(OXT)-and vasopressin(VP)-positive neurons,as well as their double labeling was detected by immunohistochemical and immunofluorescent staining.Cell counting and comparison were made in groups.Results:FOS expression was easily detected in the PVN in the three groups(Control group,DNP group and DWP group)at 7 days,while that in DWP and DNP groups at 28 days was hardly detectable,with the number being signifi-cantly different from the 7 days group(P<0.05 or 0.001).Likewise,compared with the control group,immunofluo-rescent signals for VP and OXT staining in the DNP and DWP groups also showed a trend of weakening as the modeling time increased(P<0.05).The cell counting after double staining for VP or OXT with FOS showed that,in the DWP group at 7 days,the number of VP and FOS double-labeled neurons was 74.33±22.10,accounting for(56.64± 7.52)%of VP-positive cells,whereas the double labeling rate for OXT and FOS was only(10.44±3.14)%.In the DNP group at 7 days,the number of OXT and FOS double-labeled neurons was 51.00±31.80,accounting for(18.50 ±9.51)%of OXT-positive neurons,whereas the double labeling rate for VP and FOS was only(9.34±3.27)%.In contrast to these changes in 7 days group,the expression of FOS decreased sharply in the group of 28 days,thereby al-most no double-labeled neurons.Conclusion:The plasticity changes of oxytocin-and vasopressin-positive neurons in the PVN are different depending on the status of pain and non-pain,and the stage of disease progression.Understanding the changes is of great significance for unravelling the neural mechanism of diabetes and its complications.
6.6-hydroxydopamine induces mechanical hyperalgesia reaction in rats through p38 MAPK signaling pathway
Ningning MA ; Na LUO ; Tong MU ; Zhihong SUN
Chinese Journal of Neuroanatomy 2024;40(1):43-49
Objective:To study the regulatory mechanism of p38 MAPK signaling pathway participate in hyperalge-sia reaction in Parkinson's disease(PD)rats model induced by 6-hydroxy dopamine(6-OHDA).Methods:Forty male Sprague Dawley(SD)rats were randomly divided into four groups:Sham group(Sham),model group(6-OHDA),p38 MAPK inhibitor SB203580 treatment group(6-OHDA+SB203580)and p38 MAPK activator anisomycin(ANS)treatment group(6-OHDA+ANS).PD model was established by intra-striatal injection of 6-OHDA stereotactically.6-OHDA+SB203580 and 6-OHDA+ANS groups was injected with 6-OHDA to establish PD model,and treated with inhibitor SB203580 or activator ANS respectively.The von Frey hairs were applied to measure the mechanical paw with-draw threshold(PWT)of rats.Enzyme linked immunosorbent assay(ELISA)was used to detect the content of IL-6,IL-1β,and TNF-α in rat dorsal root ganglion(DRG).The mRNA levels of genes IL-6,IL-1β,TNF-α,and p38 MAPK in rat DRG was detected by real time RT-PCR.Results:In the DRG of 6-OHDA included PD rats,the expres-sion levels of IL-6,IL-1β,TNF-α,and p38 MAPK were significantly increased(P<0.05),and the PWT of rats were significantly decreased(P<0.05).The application of activator ANS further increased the expression levels of IL-6,IL-1β,TNF-α,and p38 MAPK,and the PWT of rats were decreased.After application of inhibitor SB203580,the ex-pression levels of IL-6,IL-1β,TNF-α and p38 MAPK were significantly decreased in the DRG of rats(P<0.05),and the PWT were significantly increased in rats(P<0.05).Conclusion:6-OHDA induces mechanical hyperalgesia reaction in rats,and the molecular mechanism is related to activation of the p38 MAPK signalling pathway.
7.The effects of gastrodin on TLR4 expression in microglia induced by ischemia and hypoxia
Shunda LI ; Yongqiang ZHAO ; Xueke YANG ; Shuyu CHEN ; Yan YANG ; Yun YUAN
Chinese Journal of Neuroanatomy 2024;40(1):50-56
Objective:To determine the effect of gastrodin(GAS)on toll-like receptor 4(TLR4)expression in mi-croglia after hypoxic-ischemic brain damage.Methods:Hypoxia-ischemic brain damage(HIBD)model was established in neonatal rat in vivo.Thirty 3 d SD rats of were randomly divided into there groups:Sham group,HIBD model group,HIBD model+gastrodin intervention group(HIBD+G).Oxygen glucose deprivation(OGD)model was established in BV2 cells in vitro,Control group(Control),oxygen glucose deprivation group(OGD),OGD+gastrodin intervention group(OGD+G)were randomly set in vitro.Both Western Blot and immunofluorescence staining techniques were used to detect the expression of TLR4 in cells of each group in vitro and in the left corpus callosum region in vivo.Results:The expression of TLR4 was significantly increased in OGD-induced microglia.After gastrodin intervention,TLR4 expression was decreased significantly(P<0.05).Conclusion:GAS can inhibit the expression of TLR4 in activated microglia and thus play a neuroprotective role in HIBD.
8.Ilex pubescens var.kwangsiensis improved radiation-induced cognitive impairment of mice by inhibiting oxidative stress
Ting LI ; Gaigai HE ; Linsha KONG ; Lin RUAN ; Shaojun WANG ; Li WEI
Chinese Journal of Neuroanatomy 2024;40(1):57-64
Objective:To investigate the improvement of radiation-induced cognitive dysfunction and its preliminary mechanism by Ilex pubescens var.kwangsiensis.Methods:SPF grade male Kunming mice were randomly divided into control group(Control),Ilex pubescens var.kwangsiensis(IP),radiation group(Rad)and radiation+Ilex pubescens var.kwangsiensiss group(Rad+IP),with 10 mice in each group.Morris water maze test and dark avoidance test were used to detect the changes in cognitive function of mice before and after drug intervention.Hematoxylin-eosin(HE)staining and electron microscopy were used to observe the changes of brain histopathology and ultrastructure in the hip-pocampus of mice.The expressions of nuclear factor E2-associated factor 2(Nrf2),heme oxygenase 1(HO-1),man-ganese superoxide dismutase(MnSOD),B-cell lymphoma/leukemia-2(Bcl-2)and Bcl-2 associated X protein(Bax)were detected by immunohistochemical assay.Results:The expressions of MnSOD and Bcl-2 in hippocampal tissue of mice in Rad group were significantly decreased,the expressions of Nrf2,Bax and HO-1 were significantly increased,and the nuclear translocation of Nrf2 was also significantly increased.After intervention,he expressions of MnSOD,Nrf2 and HO-1 were significantly increased,and the apoptosis rate was significantly decreased.Conclusion:Ilex pu-bescens var.kwangsiensis improved cognitive dysfunction in mice after radiation,and the mechanism may be related to Nrf2 activation and regulation of HO-1 transcription and expression,reducing oxidative stress damage.
9.Mito-TEMPO inhibits the activation of BV2 microglia induced by lead exposure by reducing mitochondrial damage
Chao CHEN ; Zaihua ZHAO ; Tao WANG ; Jinsuo LU ; Gang ZHENG
Chinese Journal of Neuroanatomy 2024;40(1):65-72
Objective:To explore the mechanism of Mito-TEMPO inhibiting the activation of BV2 microglia induced by lead(Pb)exposure.Methods:Mouse microglia BV2 were cultured in vitro.The effects of different concentrations of lead exposure on the viability of BV2 cells were determined by MTT colorimetric method,and a model of lead expo-sure was developed and intervened with Mito-TEMPO antioxidant.Immunofluorescence staining was used to detect the expression of M1 activation marker CD86 protein.Enzyme-linked immunosorbent assay was used to detect the expression of pro-inflammatory factors interleukin-1 β(IL-1β),tumor necrosis factor α(TNF-α),interleukin-6(IL-6).Mito-chondrial superoxide indicator(MitoSOX)staining was used to detect the level of mitochondrial oxidative stress.JC-1 staining was used to detect mitochondrial membrane potential.The respiratory ability of mitochondria was detected by cell energy metabolism analysis system(O2k).Results:Compared with the control group,the expression of CD86 protein,the levels of pro-inflammatory cytokines IL-1β,TNF-α and IL-6 in BV2 cells increased significantly,the level of oxidative stress in mitochondria increased significantly,and the mitochondrial membrane potential and respiratory ability decreased significantly in lead exposed group.Mito-TEMPO treatment significantly reduced the oxidative stress and functional damage of mitochondria in BV2 cells,and significantly inhibited the M1 activation level of BV2 cells.Conclusion:The results show that Mito-TEMPO treatment can reverse the M1 activation of BV2 cells induced by lead exposure,and the specific mechanism may be related to the reduction of mitochondrial oxidative stress and dysfunction by Mito-TEMPO.
10.The effects of minocycline on neuroinflammation in rats with post-traumatic stress disorder
Chong ZHANG ; Zuolin SHI ; Zhen WANG ; Yushu DONG
Chinese Journal of Neuroanatomy 2024;40(1):73-77
Objective:To investigate the effect of minocycline on neuroinflammation of rats with post-traumatic stress disorder(PTSD).Methods:The rat model of PTSD was prepared by a single prolonged stress(SPS)method,and the rats were treated with minocycline(PTSD+Mino group)or normal saline(PTSD group)by gavage.The behavioral changes of rats were detected by light-dark box test.The expression of ionized calcium-binding adapter molecule 1(Iba-1)in hippocampus was detected by immunohistochemical staining.The contents of IL-1β and TNF-α in hippocampus were detected by ELISA,and the expression levels of IL-1β and TNF-α mRNA in hippocampus were detected by real-time RT-PCR(qRT-PCR).Results:After 3 days of SPS stimulation,the anxiety-like behavior of rats was obvious,the expression of Iba-1 in hippocampus was increased,and the contents of IL-1β and TNF-α in hippocampus were in-creased.Minocycline treatment significantly reduced anxiety-like behavior and decreased the expression of Iba-1 in the hippocampus of PTSD rats.Meanwhile,minocycline treatment also decreased the levels of IL-1β and TNF-α mRNA and protein in the hippocampus.Conclusion:Minocycline can improve the anxiety-like behavior of PTSD rats by inhibiting the activation of microglia.

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