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 explore the expression and ultrastructure distribution of cofilin and its potential mecha-nisms in postsynaptic mitochondrial anchoring and synaptic plasticity in the pre-B?tzinger complex(pre-B?tC)in rats.Methods:Using neurokinin 1 receptor(NK1R)as a morphological marker of the pre-B?tC,we examined the expres-sion and ultrastructure distribution of cofilin in pre-B?tC neurons of normoxic(NOR)and acute intermittent hypoxic(AIH)rats by combining Western blot,RT-qPCR,immunofluorescence,and immunoelectron microscopy.Results:Cofilin was expressed in the nuclei,somata and dendrites of NK1R-positive neurons in the pre-B?tC and its expression decreased after AIH intervention in this region detected.The results of immunoelectron microscopy showed that cofilin was expressed in the dendritic spines and postsynaptic filamentous or flocculent structures of pre-B?tC neurons.A total of 317 synapses were detected in pre-B?tC(NOR:122;AIH:195).In the NOR group,65.6％of the postsynaptic had cofilin expression,while in the AIH group,the proportion decreased to 47.2％.Combining with the role of cofilin in the regulation of actin severing,it is suggested that the severing effect of cofilin on postsynaptic actin is weakened af-ter AIH intervention,which may further enhance the postsynaptic mitochondrial anchoring.Conclusion:Cofilin,an ac-tin binding protein,plays a crucial role in regulating shearing and depolymerization of actin.Decreased cofilin expres-sion induced by AIH suggests an enhanced actin polymerization,which may be involved in the postsynaptic anchoring of mitochondria and the regulation of synaptic plasticity in the pre-B?tC.

Objective:To evaluate the role and molecular mechanism of laminin β1(LAMB1)in cortical neurons in regulation of glutamate receptors.Methods:Recombinant lentivirus(LV-shLamb1)-mediated knockdown of LAMB1 expression in mouse primary cortical neurons was performed,followed by immunofluorescence staining and Western blot to detect changes in F-actin,glutamate receptor subtypes(AMPA receptors GluR1/GluR2,NMDA receptors NR1/NR2A),and ERK-related protein expression in cortical neurons.Results:LV-shLamb1 significantly inhibited LAMB1 expression in mouse cortical neurons.Concurrently,LV-shLamb1 markedly increased F-actin polymerization,as well as the expression of AMPA receptor subunits GluR1 and GluR2,and NMDA receptor subunits NR1 and NR2A.Further,Western blot detection showed that the phosphorylation level of ERK was significantly increased after LV-shLamb1 infec-tion.Conclusion:LAMB1 is expressed in cortical neurons.Suppression of LAMB1 expression in mouse cortical neu-rons activates the ERK pathway,which in turn promotes the polymerization of the cytoskeletal protein F-actin and the expression of glutamate receptors.This suggests that LAMB1 may regulate F-actin homeostasis and glutamate receptor levels through the ERK pathway,thereby playing a potentially important role in neuronal function.

Objective:To compare the differential regulatory effects of corticotropin releasing hormone(CRH)neu-rons in periaqueductal gray(PAG)and medial preoptic area(MPA)downstream of paraventricular nucleus(PVN)in mediating stress-related abnormal behaviors.Methods:The anterograde labeled virus AAV2/9-hSyn-DIO-hChR2-EYFP and AAV2/9-mCrh-SV40 NLS-Cre was injected into the PVN brain region of mouse,and the projection distribution of PVN axons in the PAG and MPA brain regions was observed after statistical analysis of its projection distribution through Image J.The optogenetic inhibitory virus mixture of AAV2/9-DIO-stGtACR2-EGFP and AAV2/9-mCrh-SV40 NLS-Cre targeting CRH neurons was injected into the PAG and MPA brain regions receiving the corresponding PVN projection,respectively,and the CRH neurons in the PAG and MPA brain regions were inhibited by optogenetic blue light 460 nm to observe the anxiety-related behaviors of mice under acute restraint stress.Results:Densely distributed CRHergic PVN axon terminals were observed in PAG and MPA brain regions.Optogenetic inhibition of CRH neurons in the PAG region of acute stress mice showed no significant change in social preference behavior.The eating latency decreased in the novelty-suppressed feeding test,and the escape latency increased under visual fear stimulation.Optogenetic inhibi-tion of CRH neurons in the MPA brain region showed no significant change in social preference,significantly decreased eating latency in the novelty-suppressed feeding test,and no significant change in escape latency under visual fear stim-ulation.Conclusion:CRH neurons in PAG and MPA brain regions downstream of PVN have differential regulation in a-cute stress-related anxiety behavior,but no difference in social behavior regulation,which provides theoretical support and basis for in-depth exploration of stress-related brain regions and cellular mechanisms.

Objective:To evaluate the role and molecular mechanism of laminin β1(LAMB1)in cortical neurons in regulation of glutamate receptors.Methods:Recombinant lentivirus(LV-shLamb1)-mediated knockdown of LAMB1 expression in mouse primary cortical neurons was performed,followed by immunofluorescence staining and Western blot to detect changes in F-actin,glutamate receptor subtypes(AMPA receptors GluR1/GluR2,NMDA receptors NR1/NR2A),and ERK-related protein expression in cortical neurons.Results:LV-shLamb1 significantly inhibited LAMB1 expression in mouse cortical neurons.Concurrently,LV-shLamb1 markedly increased F-actin polymerization,as well as the expression of AMPA receptor subunits GluR1 and GluR2,and NMDA receptor subunits NR1 and NR2A.Further,Western blot detection showed that the phosphorylation level of ERK was significantly increased after LV-shLamb1 infec-tion.Conclusion:LAMB1 is expressed in cortical neurons.Suppression of LAMB1 expression in mouse cortical neu-rons activates the ERK pathway,which in turn promotes the polymerization of the cytoskeletal protein F-actin and the expression of glutamate receptors.This suggests that LAMB1 may regulate F-actin homeostasis and glutamate receptor levels through the ERK pathway,thereby playing a potentially important role in neuronal function.

Objective:To compare the differential regulatory effects of corticotropin releasing hormone(CRH)neu-rons in periaqueductal gray(PAG)and medial preoptic area(MPA)downstream of paraventricular nucleus(PVN)in mediating stress-related abnormal behaviors.Methods:The anterograde labeled virus AAV2/9-hSyn-DIO-hChR2-EYFP and AAV2/9-mCrh-SV40 NLS-Cre was injected into the PVN brain region of mouse,and the projection distribution of PVN axons in the PAG and MPA brain regions was observed after statistical analysis of its projection distribution through Image J.The optogenetic inhibitory virus mixture of AAV2/9-DIO-stGtACR2-EGFP and AAV2/9-mCrh-SV40 NLS-Cre targeting CRH neurons was injected into the PAG and MPA brain regions receiving the corresponding PVN projection,respectively,and the CRH neurons in the PAG and MPA brain regions were inhibited by optogenetic blue light 460 nm to observe the anxiety-related behaviors of mice under acute restraint stress.Results:Densely distributed CRHergic PVN axon terminals were observed in PAG and MPA brain regions.Optogenetic inhibition of CRH neurons in the PAG region of acute stress mice showed no significant change in social preference behavior.The eating latency decreased in the novelty-suppressed feeding test,and the escape latency increased under visual fear stimulation.Optogenetic inhibi-tion of CRH neurons in the MPA brain region showed no significant change in social preference,significantly decreased eating latency in the novelty-suppressed feeding test,and no significant change in escape latency under visual fear stim-ulation.Conclusion:CRH neurons in PAG and MPA brain regions downstream of PVN have differential regulation in a-cute stress-related anxiety behavior,but no difference in social behavior regulation,which provides theoretical support and basis for in-depth exploration of stress-related brain regions and cellular mechanisms.