The seat of human intelligence is the human cerebral cortex, which is responsible for our exceptional cognitive abilities. Identifying principles that lead to the development of the large-sized human cerebral cortex will shed light on what makes the human brain and species so special. The remarkable increase in the number of human cortical pyramidal neurons and the size of the human cerebral cortex is mainly because human cortical radial glial cells, primary neural stem cells in the cortex, generate cortical pyramidal neurons for more than 130 days, whereas the same process takes only about 7 days in mice. The molecular mechanisms underlying this difference are largely unknown. Here, we found that bone morphogenic protein 7 (BMP7) is expressed by increasing the number of cortical radial glial cells during mammalian evolution (mouse, ferret, monkey, and human). BMP7 expression in cortical radial glial cells promotes neurogenesis, inhibits gliogenesis, and thereby increases the length of the neurogenic period, whereas Sonic Hedgehog (SHH) signaling promotes cortical gliogenesis. We demonstrate that BMP7 signaling and SHH signaling mutually inhibit each other through regulation of GLI3 repressor formation. We propose that BMP7 drives the evolutionary expansion of the mammalian cortex by increasing the length of the neurogenic period.
Animals ; Mice ; Humans ; Ependymoglial Cells/metabolism* ; Hedgehog Proteins/metabolism* ; Ferrets/metabolism* ; Cerebral Cortex ; Neurogenesis ; Mammals/metabolism* ; Neuroglia/metabolism* ; Bone Morphogenetic Protein 7/metabolism*

OBJECTIVE: To observe the effect of Tongdu Tiaoshen (promoting the circulation of the governor vessel and regulating the spirit) electroacupuncture (EA) pretreatment on pyroptosis mediated by peroxisome proliferators-activated receptor γ (PPARγ) of the cerebral cortex in rats with cerebral ischemia reperfusion injury (CIRI) and explore the potential mechanism of EA for the prevention and treatment of CIRI. METHODS: A total of 110 clean-grade male SD rats were randomly divided into a sham-operation group, a model group, an EA group, an EA + inhibitor group and an agonist group, 22 rats in each group. In the EA group, before modeling, EA was applied to "Baihui" (GV 20), "Fengfu" (GV 16) and "Dazhui" (GV 14), with disperse-dense wave, 2 Hz/5 Hz in frequency, 1 to 2 mA in intensity, lasting 20 min; once a day, consecutively for 7 days. On the base of the intervention as the EA group, on the day 7, the intraperitoneal injection with the PPARγ inhibitor, GW9662 (10 mg/kg) was delivered in the EA + inhibitor group. In the agonist group, on the day 7, the PPARγ agonist, pioglitazone hydrochloride (10 mg/kg) was injected intraperitoneally. At the end of intervention, except the sham-operation group, the modified thread embolization method was adopted to establish the right CIRI model in the rats of the other groups. Using the score of the modified neurological severity score (mNSS), the neurological defect condition of rats was evaluated. TTC staining was adopted to detect the relative cerebral infarction volume of rat, TUNEL staining was used to detect apoptosis of cerebral cortical nerve cells and the transmission electron microscope was used to observe pyroptosis of cerebral cortical neural cells. The positive expression of PPARγ and nucleotide-binding to oligomerization domain-like receptor protein 3 (NLRP3) in the cerebral cortex was detected with the immunofluorescence staining. The protein expression of PPARγ, NLRP3, cysteinyl aspartate specific protease-1 (caspase-1), gasdermin D (GSDMD) and GSDMD-N terminal (GSDMD-N) in the cerebral cortex was detected with Western blot. Using the quantitative real-time fluorescence-PCR, the mRNA expression of PPARγ, NLRP3, caspase-1 and GSDMD of the cerebral cortex was detected. The contents of interleukin (IL)-1β and IL-18 in the cerebral cortex of rats were determined by ELISA. RESULTS: Compared with the sham-operation group, the mNSS, the relative cerebral infarction volume and the TUNEL positive cells rate were increased (P<0.01), pyroptosis was severe, the protein and mRNA expression levels of PPARγ, NLRP3, caspase-1 and GSDMD were elevated (P<0.01); and the protein expression of GSDMD-N and contents of IL-1β and IL-18 were increased (P<0.01) in the model group. When compared with the model group, the mNSS, the relative cerebral infarction volume and the TUNEL positive cells rate were decreased (P<0.01), pyroptosis was alleviated, the protein and mRNA expression levels of PPARγ were increased (P<0.01), the protein and mRNA expression levels of NLRP3, caspase-1 and GSDMD were decreased (P<0.01), the protein expression of GSDMD-N was reduced (P<0.01); and the contents of IL-1β and IL-18 were lower (P<0.01) in the EA group and the agonist group; while, in the EA + inhibitor group, the protein expression of PPARγ was increased (P<0.01), the protein and mRNA expression levels of NLRP3 and GSDMD were decreased (P<0.01, P<0.05), the mRNA expression of caspase-1 was reduced (P<0.01); and the contents of IL-1β and IL-18 were lower (P<0.01). When compared with the EA + inhibitor group, the mNSS, the relative cerebral infarction volume and the TUNEL positive cells rate were decreased (P<0.05, P<0.01), pyroptosis was alleviated, the protein and mRNA expression levels of PPARγ were increased (P<0.01), the protein and mRNA expression levels of NLRP3, caspase-1 and GSDMD were decreased (P<0.01), the protein expression of GSDMD-N was reduced (P<0.01); and the contents of IL-1β and IL-18 were declined (P<0.01) in the EA group. Compared with the agonist group, in the EA group, the relative cerebral infarction volume and the TUNEL positive cells rate were increased (P<0.05, P<0.01), the mRNA expression of PPARγ was decreased (P<0.01) and the protein expression of GSDMD-N was elevated (P<0.05); and the contents of IL-1β and IL-18 were higher (P<0.01). CONCLUSION Tongdu Tiaoshen EA pretreatment can attenuate the neurological impairment in the rats with CIRI, and the underlying mechanism is related to the up-regulation of PPARγ inducing the inhibition of NLRP3 in the cerebral cortex of rats so that pyroptosis is affected.
Male ; Animals ; Rats ; Rats, Sprague-Dawley ; PPAR gamma/genetics* ; Pyroptosis ; Interleukin-18 ; Electroacupuncture ; NLR Family, Pyrin Domain-Containing 3 Protein ; Cerebral Cortex ; Cerebral Infarction/therapy* ; Caspases ; RNA, Messenger

Humans ; Cerebral Cortex ; Hallucinations/pathology* ; Neurodegenerative Diseases/pathology* ; Atrophy/pathology* ; Magnetic Resonance Imaging

OBJECTIVE: To investigate the changes in gray matter volume in depressive-like mice and explore the possible mechanism. METHODS: Twenty-four 6-week-old C57 mice were randomized equally into control group and model group, and the mice in the model group were subjected to chronic unpredictable mild stimulation (CUMS) for 35 days. Magnetic resonance imaging was performed to examine structural changes of the grey matter volume in depressive-like mice. The expression of brain-derived neurotrophic factor (BDNF) in the grey matter of the mice was detected using Western blotting and immunofluorescence staining. RESULTS: Compared with the control mice, the mice with CUMS showed significantly decreased central walking distance in the open field test (P < 0.05) and increased immobile time in forced swimming test (P < 0.05). Magnetic resonance imaging showed that the volume of the frontal cortex was significantly decreased in CUMS mice (P < 0.001, when the mass level was greater than or equal to 10 756, the FDRc was corrected with P=0.05). Western blotting showed that the expression of mature BDNF in the frontal cortex was significantly decreased in CUMS mice (P < 0.05), and its expression began to decrease after the exposure to CUMS as shown by immunofluorescence staining. The volume of different clusters obtained by voxel-based morphometry (VBM) analysis was correlated with the expression level of mature BDNF detected by Western blotting (P < 0.05). CONCLUSION The decrease of frontal cortex volume after CUMS is related with the reduction of mature BDNF expression in the frontal cortex.
Animals ; Mice ; Blotting, Western ; Brain-Derived Neurotrophic Factor ; Cerebral Cortex ; Depression/physiopathology* ; Frontal Lobe/pathology*

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.
Mice ; Animals ; Gyrus Cinguli/physiology* ; Pruritus/pathology* ; Mesencephalon ; Cerebral Cortex/pathology* ; Neurons/pathology*

Gray Matter/diagnostic imaging* ; Cerebral Cortex ; Brain ; Magnetic Resonance Imaging

Heterozygous loss-of-function variants of FOXP4 are associated with neurodevelopmental disorders (NDDs) that exhibit delayed speech development, intellectual disability, and congenital abnormalities. The etiology of NDDs is unclear. Here we found that FOXP4 and N-cadherin are expressed in the nuclei and apical end-feet of radial glial cells (RGCs), respectively, in the mouse neocortex during early gestation. Knockdown or dominant-negative inhibition of Foxp4 abolishes the apical condensation of N-cadherin in RGCs and the integrity of neuroepithelium in the ventricular zone (VZ). Inhibition of Foxp4 leads to impeded radial migration of cortical neurons and ectopic neurogenesis from the proliferating VZ. The ectopic differentiation and deficient migration disappear when N-cadherin is over-expressed in RGCs. The data indicate that Foxp4 is essential for N-cadherin-based adherens junctions, the loss of which leads to periventricular heterotopias. We hypothesize that FOXP4 variant-associated NDDs may be caused by disruption of the adherens junctions and malformation of the cerebral cortex.
Mice ; Animals ; Ependymoglial Cells/physiology* ; Cadherins ; Neurons/metabolism* ; Cerebral Cortex/metabolism* ; Cell Differentiation ; Cell Movement

The axon initial segment (AIS) is a highly specialized axonal compartment where the action potential is initiated. The heterogeneity of AISs has been suggested to occur between interneurons and pyramidal neurons (PyNs), which likely contributes to their unique spiking properties. However, whether the various characteristics of AISs can be linked to specific PyN subtypes remains unknown. Here, we report that in the prelimbic cortex (PL) of the mouse, two types of PyNs with axon projections either to the contralateral PL or to the ipsilateral basal lateral amygdala, possess distinct AIS properties reflected by morphology, ion channel expression, action potential initiation, and axo-axonic synaptic inputs from chandelier cells. Furthermore, projection-specific AIS diversity is more prominent in the superficial layer than in the deep layer. Thus, our study reveals the cortical layer- and axon projection-specific heterogeneity of PyN AISs, which may endow the spiking of various PyN types with exquisite modulation.
Mice ; Animals ; Axon Initial Segment ; Synapses/physiology* ; Pyramidal Cells/physiology* ; Cerebral Cortex ; Axons/physiology*

OBJECTIVE: To investigate the effect of hydrogen gas on NOD-like receptor protein 3 (NLRP3) inflammasomes in the cerebral cortex of rats with traumatic brain injury (TBI). METHODS: 120 adult male Sprague-Dawley (SD) rates were randomly divided into 5 groups (n = 24): sham operation group (S group), TBI model group (T group), TBI+NLRP3 inhibitor MCC950 group (T+M group), TBI+hydrogen gas group (T+H group), TBI+hydrogen gas+MCC950 group (T+H+M group). TBI model was established by controlled cortical impact. NLRP3 inhibitor MCC950 (10 mg/kg) was intraperitoneally injected for 14 consecutive days before TBI operation in T+M and T+H+M groups. 2% hydrogen inhalation was given for 1 hour at 1 hour and 3 hours after TBI operation in T+H and T+H+M groups. At 6 hours after TBI operation, the pericontusional cortex tissues were obtained, the content of Evans blue (EB) was detected to evaluate the permeability of the blood-brain barrier. Water content in brain tissue was detected. The cell apoptosis was detected by TdT-mediated dUTP nick end labeling (TUNEL) and the neuronal apoptosis index was calculated. The expressions of Bcl-2, Bax, NLRP3, apoptosis-associated speck-like protein containing CARD (ASC) and caspase-1 p20 were detected by Western blotting. The levels of interleukins (IL-1β, IL-18) were detected by enzyme-linked immunosorbent assay (ELISA). RESULTS: Compared with the S group, the content of EB in cerebral cortex, water content in brain tissue, apoptosis index and the expressions of Bax, NLRP3, ASC, caspase-1 p20 in T group were significantly increased, the expression of Bcl-2 was down-regulated, the levels of IL-1β and IL-18 were increased [the content of EB (μg/g): 87.57±6.89 vs. 10.54±1.15, water content in brain tissues: (83.79±2.74)% vs. (74.50±1.19)%, apoptotic index: (62.66±5.33)% vs. (4.61±0.96)%, Bax/β-actin: 4.20±0.44 vs. 1, NLRP3/β-actin: 3.55±0.31 vs. 1, ASC/β-actin: 3.10±0.26 vs. 1, caspase-1 p20/β-actin: 3.28±0.24 vs. 1, Bcl-2/β-actin: 0.23±0.03 vs. 1, IL-1β (ng/g): 221.58±19.15 vs. 27.15±3.27, IL-18 (ng/g): 87.26±7.17 vs. 12.10±1.85, all P < 0.05]. Compared with the T group, the T+M, T+H and T+H+M groups had significant reductions in the content of EB and water content in brain tissue, apoptotic index of the cerebral cortex, the expressions of Bax, NLRP3, and caspase-1 p20 in the brain tissue and the levels of IL-1β and IL-18, significant increases in the expression of Bcl-2. However, there was no significant difference in ASC expression. Compared with the T+H group, the content of EB in the cerebral cortex, water content in brain tissue, and apoptotic index, and the expressions of Bax, NLRP3 and caspase-1 p20 were further down-regulated in T+H+M group, the expression of Bcl-2 was further up-regulated, the levels of IL-1β and IL-18 were further decreased [the content of EB (μg/g): 40.49±3.15 vs. 51.96±4.69, water content in brain tissue: (76.58±1.04)% vs. (78.76±1.16)%, apoptotic index: (32.22±3.44)% vs. (38.54±3.89)%, Bax/β-actin: 1.92±0.16 vs. 2.56±0.21, NLRP3/β-actin: 1.94±0.14 vs. 2.37±0.24, caspase-1 p20/β-actin: 1.97±0.17 vs. 2.31±0.19, Bcl-2/β-actin: 0.82±0.07 vs. 0.52±0.04, IL-1β (ng/g): 86.23±7.09 vs. 110.44±10.48, IL-18 (ng/g): 40.18±3.22 vs. 46.23±4.02, all P < 0.05], but there were no statistical significance in all the indicators between T+M group and T+H group. CONCLUSIONS The mechanism by which hydrogen gas alleviates TBI may be related to inhibiting NLRP3 inflammasomes in the cerebral cortex of rats.
Male ; Animals ; Rats ; Rats, Sprague-Dawley ; Actins ; Interleukin-18 ; Inflammasomes ; NLR Family, Pyrin Domain-Containing 3 Protein ; bcl-2-Associated X Protein ; Brain Injuries, Traumatic ; Cerebral Cortex ; Caspases

Existing neuroregulatory techniques can achieve precise stimulation of the whole brain or cortex, but high-focus deep brain stimulation has been a technical bottleneck in this field. In this paper, based on the theory of negative permeability emerged in recent years, a simulation model of magnetic replicator is established to study the distribution of the induced electric field in the deep brain and explore the possibility of deep focusing, which is compared with the traditional magnetic stimulation method. Simulation results show that a single magnetic replicator realized remote magnetic source. Under the condition of the same position and compared with the traditional method of stimulating, the former generated smaller induced electric field which sharply reduced with distance. By superposition of the magnetic field replicator, the induced electric field intensity could be increased and the focus could be improved, reducing the number of peripheral wires while guaranteeing good focus. The magnetic replicator model established in this paper provides a new idea for precise deep brain stimulation, which can be combined with neuroregulatory techniques in the future to lay a foundation for clinical application.
Brain ; Cerebral Cortex ; Computer Simulation ; Electricity ; Magnetic Fields