Autism Spectrum Disorder (ASD) is marked by early-onset neurodevelopmental anomalies, yet the temporal dynamics of genetic contributions to these processes remain insufficiently understood. This study aimed to elucidate the role of the Shank3 gene, known to be associated with monogenic causes of autism, in early developmental processes to inform the timing and mechanisms for potential interventions for ASD. Utilizing the Shank3B knockout (KO) mouse model, we examined Shank3 expression and its impact on neuronal maturation through Golgi staining for dendritic morphology and electrophysiological recordings to measure synaptic function in the anterior cingulate cortex (ACC) across different postnatal stages. Our longitudinal analysis revealed that, while Shank3B KO mice displayed normal neuronal morphology at one week postnatal, significant impairments in dendritic growth and synaptic activity emerged by two to three weeks. These findings highlight the critical developmental window during which Shank3 is essential for neuronal and synaptic maturation in the ACC.
Animals ; Nerve Tissue Proteins/metabolism* ; Mice, Knockout ; Dendrites/metabolism* ; Mice ; Synapses/metabolism* ; Gyrus Cinguli/metabolism* ; Male ; Mice, Inbred C57BL ; Autism Spectrum Disorder/genetics* ; Microfilament Proteins

Normal heart function depends on complex regulation by the brain, and abnormalities in the brain‒heart axis affect various diseases, such as myocardial infarction and anxiety disorders. However, systematic tracking of the brain regions associated with the input and output of the heart is lacking. In this study, we injected retrograde transsynaptic pseudorabies virus (PRV) and anterograde transsynaptic herpes simplex virus (HSV) into the left ventricular wall of mice to identify the whole-brain regions associated with the input to and output from the heart. We successfully detected PRV and HSV expression in at least 170 brain subregions in both male and female mice. Sex differences were discovered mainly in the hypothalamus and medulla, with male mice exhibiting greater correlation and hierarchical clustering than female mice, indicating reduced similarity and increased modularity of virus expression patterns in male mice. Further graph theory and multiple linear regression analysis of different injection timelines revealed that hub regions of PRV had highly similar clusters, with different brain levels, suggesting a top-down, hierarchically transmitted neural control pattern of the heart. Hub regions of HSV had scattered clusters, with brain regions gathered in the cortex and brainstem, suggesting a bottom-up, leapfrog, multipoint neural sensing pattern of the heart. Both patterns contain many hub brain regions that have been previously overlooked in brain‒heart axis studies. These results provide brain targets for future research and will lead to deeper insight into the brain mechanisms involved in specific heart conditions.
Animals ; Male ; Female ; Heart/physiology* ; Mice ; Herpesvirus 1, Suid ; Brain/physiology* ; Mice, Inbred C57BL ; Brain Mapping ; Efferent Pathways/physiology* ; Afferent Pathways/physiology* ; Simplexvirus ; Sex Characteristics

Chronic pain, frequently comorbid with neuropsychiatric disorders, significantly impairs patients' quality of life and functional capacity. Accumulating evidence implicates the chemokine CCL2 and its receptor CCR2 as key players in chronic pain pathogenesis. This review examines the regulatory mechanisms of the CCL2/CCR2 axis in chronic pain processing at three hierarchical levels: (1) Peripheral Sensitization: CCL2/CCR2 modulates TRPV1, Nav1.8, and HCN2 channels to increase neuronal excitability and CGRP signaling and calcium-dependent exocytosis in peripheral nociceptors to transmit pain. (2) Spinal Cord Central Sensitization: CCL2/CCR2 contributes to NMDAR-dependent plasticity, glial activation, GABAergic disinhibition, and opioid receptor desensitization. (3) Supraspinal Central Networks: CCL2/CCR2 signaling axis mediates the comorbidity mechanisms of pain with anxiety and cognitive impairment within brain regions, including the ACC, CeA, NAc, and hippocampus, and it also increases pain sensitization through the descending facilitation system. Current CCL2/CCR2-targeted therapeutic strategies and their development status are discussed, highlighting novel avenues for chronic pain management.
Humans ; Chronic Pain/physiopathology* ; Animals ; Neuroglia/metabolism* ; Chemokine CCL2/metabolism* ; Receptors, CCR2/metabolism*

The anterior cingulate cortex (ACC) has recently been proposed as a key player in the representation of itch stimuli. However, to date, little is known about the contribution of specific ACC interneuron populations to itch processing. Using c-Fos immunolabeling and in vivo Ca²⁺ imaging, we reported that both histamine and chloroquine stimuli-induced acute itch caused a marked enhancement of vasoactive intestinal peptide (VIP)-expressing interneuron activity in the ACC. Behavioral data indicated that optogenetic and chemogenetic activation of these neurons reduced scratching responses related to histaminergic and non-histaminergic acute itch. Similar neural activity and modulatory role of these neurons were seen in mice with chronic itch induced by contact dermatitis. Together, this study highlights the importance of ACC VIP⁺ neurons in modulating itch-related affect and behavior, which may help us to develop novel mechanism-based strategies to treat refractory chronic itch in the clinic.
Animals ; Pruritus/physiopathology* ; Vasoactive Intestinal Peptide/metabolism* ; Interneurons/metabolism* ; Gyrus Cinguli/metabolism* ; Mice ; Male ; Mice, Inbred C57BL ; Histamine ; Chloroquine ; Optogenetics ; Mice, Transgenic

Objective:To analyze the effect of depressive state on Alzheimer's disease(AD)mice,3xTg-AD mice were stimulated with chronic social frustration stress(CSDS)and chronic mild unpredictable stress(CUMS),to estab-lish an early AD-induced depression mouse model,and to detect cognitive and behavioral changes,activation of micro-glia in the hippocampus and neuronal loss.Methods:Three-month-old mice were subjected to 8-day stress stimulation alternately,the depressive state of the mice was evaluated by behavior,the evaluation criteria were formulated,and the cognitive behavior was detected and analyzed,and the hippocampal brain tissue sections were stained with immunofluo-rescence to observe the deposition of β-amyloid(Aβ)and the aggregation of microtubule-associated protein(tau),mi-croglia activation and neuronal loss.Results:Depression-related behavioral results showed that the CSDS+CUMS group had depression-related phenotypes.Cognitive-behavioral testing showed that the new object recognition index of the mice in the CSDS+CUMS group was significantly reduced(P＜0.05),and the Morris water maze showed that the spatial memory ability of the CSDS+CUMS group was significantly reduced(P＜0.05),but there was no obvious fear memory loss in the CSDS+CUMS group in the conditioned fear experiment.The results of immunofluorescence staining showed that Aβ deposition appeared in the hippocampus at 4 months of age,the activated microglia increased(P＜0.001),and a certain degree of neuronal loss appeared in the CSDS+CUMS group(P＜0.001);At 8 months of age,the CSDS+CUMS group showed tau protein aggregation early.Conclusion:We established a model of AD-induced de-pression in AD mice,in which 3xTg-AD mice experienced early decline in learning memory and increased AD-related pathological deposition of neurons in the hippocampus,accompanied by microglial activation and neuronal loss.

Objective:To explore the effects of dopamine receptor D2(DRD2)on astrocytic dedifferentiation based on SOX2-regulated genes in neural stem cells(NSCs)and astrocytes.Methods:Immunofluorescence staining and SOX2-GFP mice were used to examine the lineage differentiation of SOX2-positive cells during the development of cere-bral cortex.Primary NSCs/astrocytes culture,ChIP-seq and Western Blot were adopted to analyze and verify the expres-sion of candidate genes.Pharmacological manipulation,neurosphere formation,photochemical ischemia,immunofluo-rescence staining and behavior tests were adopted to evaluate the effects of activating DRD2 signaling on astrocytic dedif-ferentiation.Results:Immunofluorescence staining demonstrated the NSC-astrocyte switch of SOX2-expression in the normal development of cerebral cortex.ChIP-seq revealed enrichment of DRD2 signaling by SOX2-bound enhancers in NSCs and SOX2-bound promoters in astrocytes.Western Blot and immunofluorescence staining verified the expression of DRD2 in NSCs and reactive astrocytes.Application of quinagolide hydrocholoride(QH),an agonist of DRD2,signifi-cantly promoted astrocytic dedifferentiation both in vitro and in vivo following ischemia.In addition,quinagolide hydro-choloride treatment improved locomotion recovery.Conclusion:Activating DRD2 signaling facilitates astrocytic dedif-ferentiation and may be used to treat ischemic stroke.

Objective:To analyze the activation of primary somatosensory cortex(S1)neurons in post-traumatic stress disorder(PTSD)mice after tactile stimulation of whiskers and the changes of S1 cortical neurons in PTSD mice.Methods:Using the neuron cytoskeleton-associated protein(Arc)labeling strategy and immunofluorescence staining technique,the Arc of S1 cortical neurons in PTSD mice and control mice after whisker stimulation was marked and ob-served.By analyzing the difference in the spatial expression position of Arc labeled neurons and the number of positive cells,the activation level of S1 cortical neurons in the two groups was compared and analyzed.The pyramidal neurons of S1 cortex were labeled by sparse virus labeling method,and the number of dendrites and the morphology and number distribution of dendritic spines were compared between the two groups.Results:After whisker stimulation,it was found that Arc positive neurons were distributed from shallow layer to deep layer of S1,and more densely distributed in layersⅡ/Ⅲ and V.Compared with the control group,the number of positive neurons in different layers of the PTSD group was significantly increased.The results of cell morphology and structure analysis showed that,compared with the control group,the density of dendritic spines in layer Ⅱ/Ⅲ of mice with PTSD increased,and the number of mushroom dendrit-ic spines increased,while the number of filamentous pseudopod dendritic spines decreased.The number of dendritic spines of Si V layer mushroom type and slender type was higher,but the total number of dendritic spines was not sig-nificantly different.Conclusion:After whisker stimulation in PTSD mice,S1 neurons were over-activated,and the structure and morphology of neurons changed significantly.

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.

Objective To study the effect of leucine rich repeat kinase 2(LRRK2)on pain sensitivity in neuro-pathic pain(NP)rats and explore its possible mechanism.Methods 48 SD rats were randomly divided into four groups:sham surgery(Sham),model,LRRK2 inhibitor(MLi-2),and LRRK2 inhibitor+p3 8 mitogen activated pro-tein kinase(MAPK)agonist(MLi-2+Anisomycin),with 12 rats in each group.The NP rat model was induced by chronic constriction injury(CCI)of the sciatic nerve.Intrathecal injection of MLi-2(1 mg/kg,10 μl)or Anisomy-cin(20 μmol/L,10 μl)was started from the 8th day after surgery,once a day for 7 consecutive days.Pain sensi-tivity tests were conducted before surgery(day 0)and on postoperative days 7 and 14,respectively.The changes in mechanical withdrawal threshold(MWT)and paw withdraw thermal latency(PWTL)were analyzed in each group of rats.ELISA was used to detect the levels of interleukin-1 β(IL-1β),IL-6 and tumor necrosis factor-α(TNF-α)in the dorsal horn of the rat spinal cord.Nissl staining was used to observe the pathological changes of neurons in rat spinal cord tissue.Immunofluorescence staining was used to observe the expression levels of ionized calcium-binding adapter molecule-1(Iba-1),a marker of microglia in the spinal cord of rats.Western blot was used to detect the protein expression levels of LRRK2,p-p38 mitogen activated protein kinase(MAPK),p38 MAPK,and Iba-1 in the dorsal horn of the rat spinal cord.Results Compared with the sham group,the model group showed a significant decrease in MWT and PWTL in the right hind limb of rats(P＜0.01).The levels of IL-1,IL-6,and TNF in the spi-nal dorsal horn tissue,as well as the expression levels of LRRK2,Iba-1 proteins and p-p38 MAPK/p38 MAPK pro-tein ratio significantly increased(P＜0.01).The proportion of Iba-1 positive cells in the spinal cord tissue signifi-cantly increased(P＜0.01),while Nissl bodies were significantly reduced(P＜0.01).Compared with the model group,the MLi-2 group showed a significant increase in MWT and PWTL in the right hind limb of rats(P＜0.01),a significant increase in Nissl bodies(P＜0.01),a significant decrease in the proportion of Iba-1 positive cells in the spinal cord tissue(P＜0.01),and a significant decrease in the levels of IL-1,IL-6,and TNF and the expression levels of LRRK2,Iba-1 proteins and p-p38 MAPK/p38 MAPK protein ratio(P＜0.01).However,Anisomychin in-tervention could activate the p38 MAPK signaling pathway and partially reverse the beneficial effects of MLi-2 on pain sensitivity and neuroinflammation in rats with neuropathic pain.Conclusion Inhibiting the expression of LRRK2 can alleviate pain sensitivity in NP rats induced by microglia activation mediated neuroinflammation,and its mechanism of action may be related to regulating the p38 MAPK signaling pathway.