TFEB overexpression through GFAP promoter disrupts neuronal lamination by dysregulating neurogenesis during embryonic development.

INTRODUCTION: Transcription factor EB (TFEB), a key regulator of autophagy and lysosomal biogenesis, has diverse roles in various physiological processes. Enhancing lysosomal function by TFEB activation has recently been implicated in restoring neural stem cells (NSCs) function. Overexpression of TFEB can inhibit the cell cycle of newborn cortical NSCs. It has also been found that TFEB regulates the pluripotency transcriptional network in mouse embryonic stem cells independent of autophagy lysosomal biogenesis. This study aims to explore the effects of TFEB activation on neurogenesis in vivo through transgenic mice. METHODS: We developed a GFAP-driven TFEB overexpression mouse model (TFEB GoE) by crossing the floxed TFEB overexpression mice and hGFAP-cre mice. We performed immunohistochemical and fluorescence staining on brain tissue from newborn mice to assess neurogenesis changes, employing markers such as GFAP, Nestin, Ki67, DCX, Tbr1 and Neun to trace different stages of neural development and cell proliferation. RESULTS: TFEB GoE mice exhibited premature mortality, dying at 10-20 days after birth. Immunohistochemical analysis revealed significant abnormalities, including disrupted hippocampal structure and cortical layering. Compared to control mice, TFEB GoE mice showed a marked increase in radial glial cells (RGCs) in the hippocampus and cortex, with Ki67 staining indicating these cells were predominantly in a quiescent state. This suggests that TFEB overexpression suppresses RGCs proliferation. Additionally, abnormal distributions of migrating neurons and mature neurons were observed, highlighted by DCX, Tbr1 and Neun staining, indicating a disruption in normal neurogenesis. CONCLUSION: This study, using transgenic animals in vivo, revealed that GFAP-driven TFEB overexpression leads to abnormal neural layering in the hippocampus and cortex by dysregulating neurogenesis. Our study is the first to discover the detrimental impact of TFEB overexpression on neurogenesis during embryonic development, which has important reference significance in future TFEB overexpression interventions in NSCs for treatment.

Oxytocin neurons in the paraventricular nucleus and fear empathy among male mice.

BACKGROUND: Recent studies have identified empathy deficit as a core impairment and diagnostic criterion for people with autism spectrum disorders; however, the improvement of empathy focuses primarily on behavioural interventions without the target regulation. We sought to compare brain regions associated with empathy-like behaviours of fear and pain, and to explore the role of the oxytocin-oxytocin receptor system in fear empathy. METHODS: We used C57BL mice to establish 2 models of fear empathy and pain empathy. We employed immunofluorescence histochemical techniques to observe the expression of c-Fos throughout the entire brain and subsequently quantified the number of c-Fos-positive cells in different brain regions. Furthermore, we employed chemogenetic technology to selectively manipulate these neurons in Oxt-Cre-/+ mice to identify the role of oxytocin in this process. RESULTS: The regions activated by fear empathy were the anterior cingulate cortex, basolateral amygdala, nucleus accumbens, paraventricular nucleus (PVN), lateral habenula, and ventral and dorsal hippocampus. The regions activated by pain empathy were the anterior cingulate cortex, basolateral amygdala, nucleus accumbens, and lateral habenula. We found that increasing the activity of oxytocin neurons in the PVN region enhanced the response to fear empathy. This enhancement may be mediated through oxytocin receptors. LIMITATIONS: This study included only male animals, which restricts the broader interpretation of the findings. Further investigations on circuit function need to be conducted. CONCLUSION: The brain regions implicated in the regulation of fear and pain empathy exhibit distinctions; the activity of PVN neurons was positively correlated with empathic behaviour in mice. These findings highlight the role of the PVN oxytocin pathway in regulating fear empathy and suggest the importance of oxytocin signalling in mediating empathetic responses.

Environmental enrichment alleviates hyperalgesia by modulating central sensitization in a nitroglycerin-induced chronic migraine model of mice.

BACKGROUND: Chronic migraine (CM) is a debilitating neurofunctional disorder primarily affecting females, characterized by central sensitization. Central sensitization refers to the enhanced response to sensory stimulation, which involves changes in neuronal excitability, synaptic plasticity, and neurotransmitter release. Environmental enrichment (EE) can increase the movement, exploration, socialization and other behaviors of mice. EE has shown promising effects in various neurological disorders, but its impact on CM and the underlying mechanism remains poorly understood. Therefore, the purpose of this study was to determine whether EE has the potential to serve as a cost-effective intervention strategy for CM. METHODS: A mouse CM model was successfully established by repeated administration of nitroglycerin (NTG). We selected adult female mice around 8 weeks old, exposed them to EE for 2 months, and then induced the CM model. Nociceptive threshold tests were measured using Von Frey filaments and a hot plate. The expression of c-Fos, calcitonin gene-related peptide (CGRP) and inflammatory response were measured using WB and immunofluorescence to evaluate central sensitization. RNA sequencing was used to find differentially expressed genes and signaling pathways. Finally, the expression of the target differential gene was investigated. RESULTS: Repeated administration of NTG can induce hyperalgesia in female mice and increase the expression of c-Fos and CGRP in the trigeminal nucleus caudalis (TNC). Early exposure of mice to EE reduced NTG-induced hyperalgesia in CM mice. WB and immunofluorescence revealed that EE inhibited the overexpression of c-Fos and CGRP in the TNC of CM mice and alleviated the inflammatory response of microglia activation. RNA sequencing analysis identified that several central sensitization-related signaling pathways were altered by EE. VGluT1, a key gene involved in behavior, internal stimulus response, and ion channel activity, was found to be downregulated in mice exposed to EE. CONCLUSION: EE can significantly ameliorate hyperalgesia in the NTG-induced CM model. The mechanisms may be to modulate central sensitization by reducing the expression of CGRP, attenuating the inflammatory response, and downregulating the expression of VGluT1, etc., suggesting that EE can serve as an effective preventive strategy for CM.

Experiences Shape Hippocampal Neuron Morphology and the Local Levels of CRHR1 and OTR.

The dorsal hippocampus is involved in behavioral avoidance regulation. It is unclear how experiences such as the neonatal stress of maternal deprivation (MD) and post-weaning environmental enrichment (EE) affect avoidance behavior and the dorsal hippocampal parameters, including neuronal morphology, corticotrophin-releasing hormone (CRH) signaling, and oxytocin receptor (OTR) level. In male BALB/c mice, we found that MD impaired avoidance behavior in the step-on test compared to non-MD and EE rearing conditions could alleviate that partially. MD increased neuronal branches in the CA1 but decreased synaptic connection levels in the CA2, CA3, and DG. Meanwhile, MD increased the CA1's OTR levels, which negatively correlated with nucleus densities. MD also increased the CA1's and CA2's CRH levels, which positively correlated with CRHR1 levels. However, MD statistically elevated the CA3's CRH receptor 1 (CRHR1) levels, which negatively correlated with nucleus densities and, probably, synaptic connection levels in the CA3. The additive effects of MD and EE maintained similar CRH levels and CRHR1 levels as well as OTR levels in the hippocampal areas as the additive of non-MD and non-EE. However, the presence of MD and EE still decreased the CA1's neuronal branches and the CA2's and DG's synaptic connection levels. The study illustrates how MD and EE affect avoidance behaviors, hippocampal neuron morphology, and CRH and OTR levels. The results indicate that the late-life environmental improvement partially restores the alterations in dorsal hippocampal areas induced by early life stress.

Simultaneous Sensing of H2S and ATP with a Two-Photon Fluorescent Probe in Alzheimer's Disease: toward Understanding Why H2S Regulates Glutamate-Induced ATP Dysregulation.

Energy deprivation and reduced levels of hydrogen sulfide (H2S) in the brain is closely associated with Alzheimer's disease (AD). However, there is currently no fluorescent probe for precise exploration of both H2S and adenosine triphosphate (ATP) to directly demonstrate their relationship and their dynamic pattern changes. Herein, we developed a two-photon fluorescent probe, named AD-3, to simultaneously image endogenous H2S and ATP from two emission channels of fluorescent signals in live rat brains with AD. The probe achieved excellent selectivity and good detection linearity for H2S in the 0-100 µM concentration range and ATP in the 2-5 mM concentration range, respectively, with a detection limit of 0.19 µM for H2S and 0.01 mM for ATP. Fluorescence imaging in live cells reveals that such probe could successfully apply for simultaneous imaging and accurate quantification of H2S and ATP in neuronal cells. Further using real-time quantitative polymerase chain reaction and Western blots, we confirmed that H2S regulates ATP synthesis by acting on cytochrome C, cytochrome oxidase subunit 3 of complex IV, and protein 6 of complex I in the mitochondrial respiratory chain. Subsequently, we constructed a high-throughput screening platform based on AD-3 probe to rapidly screen the potential anti-AD drugs to control glutamate-stimulated oxidative stress associated with abnormal H2S and ATP levels. Significantly, AD-3 probe was found capable of imaging of H2S and ATP in APP/PS1 mice, and the concentration of H2S and ATP in the AD mouse brain was found to be lower than that in wild-type mice.

Noncanonical Roles of hα-syn (A53T) in the Pathogenesis of Parkinson's Disease: Synaptic Pathology and Neuronal Aging.

The motor and nonmotor symptoms of PD involve several brain regions. However, whether α-syn pathology originating from the SNc can directly lead to the pathological changes in distant cerebral regions and induce PD-related symptoms remains unclear. Here, AAV9-synapsin-mCherry-human SNCA (A53T) was injected into the unilateral SNc of mice. Motor function and olfactory sensitivity were evaluated. Our results showed that AAV9-synapsin-mCherry-human SNCA was continuously expressed in SNc. The animals showed mild motor and olfactory dysfunction at 7 months after viral injection. The pathology in SNc was characterized by the loss of dopaminergic neurons accompanied by ER stress. In the striatum, hα-syn expression was high, CaMKß-2 and NR2B expression decreased, and active synapses reduced. In the olfactory bulb, hα-syn expression was high, and aging cells in the mitral layer increased. The results suggested that hα-syn was transported in the striatum and OB along the nerve fibers that originated from the SNc and induced pathological changes in the distant cerebral regions, which contributed to the motor and nonmotor symptoms of PD.

Protective effect of metformin against rotenone-induced parkinsonism in mice.

Rotenone is a mitochondrial complex I inhibitor, which can cause the death of dopaminergic (DA) neurons and Parkinson's disease (PD). Currently, whether metformin has a protective effect on neurotoxicity induced by rotenone is unclear. The purpose of this study was to evaluate the potential protective effect of metformin against rotenone-induced neurotoxicity. PD animal model was established by unilateral rotenone injection into the right substantia nigra (SN) of C57BL/6 mice. The behavioral tests were performed by rotarod test and cylinder test. The numbers of TH-positive neurons and Iba-1 positive microglia in the SN were investigated by immunohistochemical staining. The mRNA levels of proinflammatory cytokines (TNF-α and IL-1ß) and molecules involved in endoplasmic reticulum (ER) stress (ATF4, ATF6, XBP1, Grp78, and CHOP) in the midbrain were detected by Quantitative real-time PCR. This study showed that 50 mg/kg metformin given orally daily, beginning 3 d before rotenone injection and continuing for 4 weeks following rotenone injection, significantly ameliorated dyskinesia, increased the number of TH-positive neurons, and mitigated the activation of microglia in the SN in rotenone-induced PD mice. Furthermore, 50 mg/kg metformin markedly downregulated the expression of proinflammatory cytokines (TNF-α and IL-1ß) and ER stress-related genes (ATF4, ATF6, XBP1, Grp78, and CHOP) in rotenone-induced PD mice. Metformin has a protective effect on DA neurons against rotenone-induced neurotoxicity through inhibiting neuroinflammation and ER stress in PD mouse model.

Interaction of basolateral amygdala, ventral hippocampus and medial prefrontal cortex regulates the consolidation and extinction of social fear.

BACKGROUND: Following a social defeat, the balanced establishment and extinction of aversive information is a beneficial strategy for individual survival. Abnormal establishment or extinction is implicated in the development of mental disorders. This study investigated the time course of the establishment and extinction of aversive information from acute social defeat and the temporal responsiveness of the basolateral amygdala (BLA), ventral hippocampus (vHIP) and medial prefrontal cortex (mPFC) in this process. METHODS: Mouse models of acute social defeat were established by using the resident-intruder paradigm. To evaluate the engram of social defeat, the intruder mice were placed into the novel context at designated time to test the social behavior. Furthermore, responses of BLA, vHIP and mPFC were investigated by analyzing the expression of immediate early genes, such as zif268, arc, and c-fos. RESULTS: The results showed after an aggressive attack, aversive memory was maintained for approximately 7 days before gradually diminishing. The establishment and maintenance of aversive stimulation were consistently accompanied by BLA activity. By contrast, vHIP and mPFC response was inhibited from this process. Additionally, injecting muscimol (Mus), a GABA receptor agonist, into the BLA alleviated the freezing behavior and social fear and avoidance. Simultaneously, Mus treatment decreased the zif268 and arc expression in BLA, but it increased their expression in vHIP. CONCLUSION: Our data support and extend earlier findings that implicate BLA, vHIP and mPFC in social defeat. The time courses of the establishment and extinction of social defeat are particularly consistent with the contrasting BLA and vHIP responses involved in this process.

Lipid accelerating the fibril of islet amyloid polypeptide aggravated the pancreatic islet injury in vitro and in vivo.

BACKGROUND: The fibrillation of islet amyloid polypeptide (IAPP) triggered the amyloid deposition, then enhanced the loss of the pancreatic islet mass. However, it is not clear what factor is the determinant in development of the fibril formation. The aim of this study is to investigate the effects of lipid on IAPP fibril and its injury on pancreatic islet. METHODS: The fibril form of human IAPP (hIAPP) was tested using thioflavin-T fluorescence assay and transmission electron microscope technology after incubated with palmitate for 5 h at 25 °C. The cytotoxicity of fibril hIAPP was evaluated in INS-1 cells through analyzing the leakage of cell membrane and cell apoptosis. Type 2 diabetes mellitus (T2DM) animal model was induced with low dose streptozotocin combined the high-fat diet feeding for two months in rats. Plasma biochemistry parameters were measured before sacrificed. Pancreatic islet was isolated to evaluate their function. RESULTS: The results showed that co-incubation of hIAPP and palmitate induced more fibril form. Fibril hIAPP induced cell lesions including cell membrane leakage and cell apoptosis accompanied insulin mRNA decrease in INS-1 cell lines. In vivo, Plasma glucose, triglyceride, rIAPP and insulin increased in T2DM rats compared with the control group. In addition, IAPP and insulin mRNA increased in pancreatic islet of T2DM rats. Furthermore, T2DM induced the reduction of insulin receptor expression and cleaved caspase-3 overexpression in pancreatic islet. CONCLUSIONS: Results in vivo and in vitro suggested that lipid and IAPP plays a synergistic effect on pancreatic islet cell damage, which implicated in enhancing the IAPP expression and accelerating the fibril formation of IAPP.

Autophagy plays beneficial effect on diabetic encephalopathy in type 2 diabetes: studies in vivo and in vitro.

OBJECTIVES: The hypothalamus regulates metabolism and feeding behavior by perceiving the levels of peripheral insulin. However, little is known about the hypothalamic changes after aberrant metabolism. In this study, we investigated the changes of insulin and autophagy relevant signals of hypothalamus under diabetes mellitus. METHODS: C57B/L mice were injected with low-dose streptozotocin (STZ) and fed with high-fat diet to induce type 2 diabetes mellitus. In vitro, PC12 cells were treated with oleic acid to mimic lipotoxicity. RESULTS: Results showed that the cholesterol level in the hypothalamus of the diabetic mice was higher than that of the normal mice. The expression of insulin receptors and insulin receptor substrate-1 were downregulated and the number of Fluoro-Jade C positive cells significantly increased in the hypothalamic arcuate nucleus of the diabetic mice. Furthermore, Upregulation of mammalian target of rapamycin (mTOR) and downregulation of LC 3II were obvious in the hypothalamus of the diabetic mice. In vitro, results showed that high-lipid caused PC12 cell damage and upregulated LC3 II expression. Pretreatment of cells with 3-methyladenine evidently downregulated LC3 II expression and aggravated PC12 cell death under high lipid conditions. By contrast, pretreatment of cells with rapamycin upregulated LC3 II expression and ameliorated PC12 cell death caused by lipotoxicity. CONCLUSION: These results demonstrate that autophagy activation confers protection to neurons under aberrant metabolism and that autophagy dysfunction in the hypothalamus occurs in the chronic metabolic disorder such as T2DM.

DNA damage preceding dopamine neuron degeneration in A53T human α-synuclein transgenic mice.

Defective DNA repair has been linked with age-associated neurodegenerative disorders. Parkinson's disease (PD) is a progressive neurodegenerative disorder caused by genetic and environmental factors. Whether damages to nuclear DNA contribute to neurodegeneration of PD still remain obscure. in this study we aim to explore whether nuclear DNA damage induce dopamine neuron degeneration in A53T human α-Synuclein over expressed mouse model. We investigated the effects of X-ray irradiation on A53T-α-Syn MEFs and A53T-α-Syn transgene mice. Our results indicate that A53T-α-Syn MEFs show a prolonged DNA damage repair process and senescense phenotype. DNA damage preceded onset of motor phenotype in A53T-α-Syn transgenic mice and decrease the number of nigrostriatal dopaminergic neurons. Neurons of A53T-α-Syn transgenic mice are more fragile to DNA damages.

DNA Damage-Induced Foci of E2 Ubiquitin-Conjugating Enzyme are Detectable upon Co-transfection with an Interacting E3 Ubiquitin Ligase.

DNA damage repair elements accumulate at DNA damage sites to form ionizing radiation-induced foci (IRIF) for damage repair. IRIF, which represent direct evidence of DNA damage response activity, which are conveniently to be observed via immunofluorescence staining. Protein ubiquitination plays an important role in initiating the DNA damage response. Following DNA damage, the substrate binding protein E3 ubiquitin-ligases enzymes are recruited to DNA damage sites, then the E2 ubiquitin-conjugating enzymes are recruited to these sites by the E3 where they catalyze protein ubiquitination. However, IRIF of E2 enzymes are relatively transient and unstable in vivo and difficult to detect. Here, we present a new method for the observation of E2 IRIF. This method is based on the co-transfection of interacting E2 and E3 enzymes into cells and identifies IRIF via immunofluorescence following DNA damage.

A ratiometric fluorescent probe revealing the abnormality of acetylated tau by visualizing polarity in Alzheimer's disease.

Abnormal neuronal polarity leads to early deficits in Alzheimer's disease (AD) by affecting the function of axons. Precise and rapid evaluation of polarity changes is very important for the early prevention and diagnosis of AD. However, due to the limitations of existing detection methods, the mechanism related to how neuronal polarity changes in AD is unclear. Herein, we reported a ratiometric fluorescent probe characterized by neutral molecule to disclose the polarity changes in nerve cells and the brain of APP/PS1 mice. Cy7-K showed a sensitive and selective ratiometric fluorescence response to polarity. Remarkably, unlike conventional intramolecular charge transfer fluorescent probes, the fluorescence quantum yield of Cy7-K in highly polar solvents is higher than that in low polar solvents due to the transition of neutral quinones to aromatic zwitterions. Using the ratiometric fluorescence imaging, we found that beta-amyloid protein (Aß) inhibits the expression of histone deacetylase 6, thereby increasing the amount of acetylated Tau protein (AC-Tau) and ultimately enhancing cell polarity. There was a high correlation between polarity and AC-Tau. Furthermore, Cy7-K penetrated the blood-brain barrier to image the polarity of different brain regions and confirmed that APP/PS1 mice had higher polarity than Wild-type mice. The probe Cy7-K will be a promising tool for assessing the progression of AD development by monitoring polarity.

High salt diet exacerbates cognitive deficits and neurovascular abnormalities in APP/PS1 mice and induces AD-like changes in wild-type mice.

High salt diet (HSD) is a risk factor of hypertension and cardiovascular disease. Although clinical data do not clearly indicate the relationship between HSD and the prevalence of Alzheimer's disease (AD), animal experiments have shown that HSD can cause hyperphosphorylation of tau protein and cognition impairment. However, whether HSD can accelerate the progression of AD by damaging the function of neurovascular unit (NVU) in the brain is unclear. Here, we fed APP/PS1 mice (an AD model) or wild-type mice with HSD and found that the chronic HSD feeding increased the activity of enzymes related to tau phosphorylation, which led to tau hyperphosphorylation in the brain. HSD also aggravated the deposition of Aß42 in hippocampus and cortex in the APP/PS1 mice but not in the wild-type mice. Simultaneously, HSD caused the microglia proliferation, low expression of Aqp-4, and high expression of CD31 in the wild-type mice, which were accompanied with the loss of pericytes (PCs) and increase in blood brain barrier (BBB) permeability. As a result, wild-type mice fed with HSD performed poorly in Morris Water Maze and object recognition test. In the APP/PS1 mice, HSD feeding for 8 months worsen the cognition and accompanied the loss of PCs, the activation of glia, the increase in BBB permeability, and the acceleration of calcification in the brain. Our data suggested that HSD feeding induced the AD-like pathology in wild-type mice and aggravated the development of AD-like pathology in APP/PS1 mice, which implicated the tau hyperphosphorylation and NVU dysfunction.

Neurodegeneration in streptozotocin-induced diabetic rats is attenuated by treatment with resveratrol.

AIM: Diabetes mellitus-associated hyperglycemia and oxidative stress have been shown to have detrimental effects on the brain and may lead to impairment of cognitive functions. Resveratrol (Rsv), a polyphenolic antioxidant, has been shown to have moderate hypoglycemic and prominent hypolipidemic effects in diabetic rats. In the present study, we examined if Rsv improves the diabetic encephalopathy and explored its possible underlying mechanisms. METHODS: Male SD rats were treated with streptozotocin (65 mg/kg), and the diabetic rats were orally fed with Rsv (0.75 mg/kg, every 8 h) or normal saline for 4 weeks. Animals were then sacrificed and the brain tissues (hippocampus) processed for biochemical and histological studies. RESULTS: Neurodegeneration and astrocytic activation were noted in the hippocampus of the diabetic rats. Tumor necrosis factor-α, IL-6 transcripts and nuclear factor-κB expression were increased in the brain. In addition, neuropathic alterations in the hippocampus were evident in diabetic rats, including increased blood vessel permeability and VEGF expression, decreased mitochondrial number and AMP-activated protein kinase activity. In Rsv-treated diabetic rats, the aforementioned abnormalities were all attenuated. CONCLUSION: These observations suggest that Rsv significantly attenuated neurodegeneration and astrocytic activation in the hippocampus of diabetic rats. Our results suggested that Rsv could potentially be a new therapeutic agent for diabetic encephalopathy and neurodegeneration.

Local CRF and oxytocin receptors correlate with female experience-driven avoidance change and hippocampal neuronal plasticity.

Understanding how experiences affect females' behaviors and neuronal plasticity is essential for uncovering the mechanism of neurodevelopmental disorders. The study explored how neonatal maternal deprivation (MD) and post-weaning environmental enrichment (EE) impacted the CA1 and DG's neuronal plasticity in the dorsal hippocampus, and its relationships with passive avoidance, local corticotrophin-releasing factor (CRF) levels, and oxytocin receptor (OTR) levels in female BALB/c mice. The results showed that MD damaged passive avoidance induced by foot shock and hotness, and EE restored it partially. In the CA1, MD raised CRF levels and OTR levels. Parallelly, MD increased synaptic connection levels but reduced the branches' numbers of pyramidal neurons. Meanwhile, in the DG, MD increased OTR levels but lowered CRF levels, DNA levels, and spine densities. EE did not change the CA1 and DG's CRF and OTR levels. However, EE added DG's dendrites of granular cells. The additive of MD and EE raised CA1's synaptophysin and DG's postsynaptic density protein-95 and OTR levels, and meanwhile, shaped avoidance behaviors primarily similar to the control. The results suggest that experience-driven avoidance change and hippocampal neuronal plasticity are associated with local CRF and OTR levels in female mice.

All-Hydrocarbon Stapled Peptide Multifunctional Agonists at Opioid and Neuropeptide FF Receptors: Highly Potent, Long-Lasting Brain Permeant Analgesics with Diminished Side Effects.

Our previous study reported the multifunctional agonist for opioid and neuropeptide FF receptors DN-9, along with its cyclic peptide analogues c[D-Cys2, Cys5]-DN-9 and c[D-Lys2, Asp5]-DN-9. These analogues demonstrated potent antinociceptive effects with reduced opioid-related side effects. To develop more stable and effective analgesics, we designed, synthesized, and evaluated seven hydrocarbon-stapled cyclic peptides based on DN-9. In vitro calcium mobilization assays revealed that most of the stapled peptides, except 3, displayed multifunctional agonistic activities at opioid and neuropeptide FF receptors. Subcutaneous administration of all stapled peptides resulted in effective and long-lasting antinociceptive activities lasting up to 360 min. Among these stapled peptides, 1a and 1b emerged as the optimized compounds, producing potent central antinociception following subcutaneous, intracerebroventricular, and oral administrations. Additionally, subcutaneous administration of 1a and 1b caused nontolerance antinociception, with limited occurrence of constipation and addiction. Furthermore, 1a was selected as the final optimized compound due to its wider safety window compared to 1b.

[Gap junction communication: alternative pattern of signal exchange in glia and neuron].

Gap junction is a direct communication between the cells as the channel, which exists widely in the central nervous system involving in transporting the electronic and chemical messages between neurons and glias. It plays roles in regulation of metabolism, ion buffer, "calcium wave" as well ATP receptor signal. Gap junction also has been complicated in the nerve growth and development. Switching the gap junction participates in pathological process and maintainning the local metabolites concentration. Calcium wave is the prominently regulated by gap junction. In the central nervous system, it is remain to be elucidated whether the gap junction play roles in embryonic development and pathophysiological processes.

Synergistic effects of hIAPP and Aß1-42 impaired the olfactory function associated with the decline of adult neurogenesis in SVZ.

According to many in the field，the prevalence of Alzheimer's disease (AD) in type II diabetes (T2DM) populations is considerably higher than that in the normal population. Human islet amyloid polypeptide (hIAPP) is considered to be a common risk factor for T2DM and AD. Preliminary observations around T2DM animal model show that the decrease of adult neural stem cells (NSCs) in the subventricular zone (SVZ) is accompanied by olfactory dysfunction. Furthermore, impaired olfactory function could serve as to an early predictor of neurodegeneration，which is associated with cognitive impairment. However, the synergistic effects between hIAPP and amyloid-beta (Aß) 1-42 in the brain and the neurodegeneration remains to be further clarified. In this study, olfactory capacity, synaptic density, status of NSC in SVZ, and status of newborn neurons in olfactory bulb (OB) were assessed 6 months after stereotactic injection of oligomer Aß1-42 into the dens gyrus (DG) of hIAPP-/+ mice or wild-type homogenous mice. Our results set out that Aß42 and amylin co-localized into OB and raised Aß42 deposition in hIAPP-/+ mice compared with wild-type brood mice. In addition, 6 months after injection of Aß1-42 in hIAPP-/+ mice, these mice showed increased olfactory dysfunction, significant loss of synapses, depletion of NSC in SVZ, and impaired cell renewal in OB. Our present study suggested that the synergistic effects between hIAPP and Aß1-42 impairs olfactory function and was associated with decreased neurogenesis in adults with SVZ.

Effects of maternal deprivation and environmental enrichment on anxiety-like and depression-like behaviors correlate with oxytocin system and CRH level in the medial-lateral habenula.

The medial-lateral habenula (LHbM)'s role in anxiety and depression behaviors in female mice remains unclear. Here, we used neonatal maternal deprivation (MD) and post-weaning environmental enrichment (EE) to treat female BALB/c offspring and checked anxiety-like and depression-like behaviors as well as the corticotropin-releasing hormone (CRH), oxytocin receptor (OTR), estrogen receptor-beta (ERß) levels in their LHbM at adulthood. We found that MD enhanced state anxiety-like behaviors in the elevated plus-maze test, and EE caused trait anxiety-like behaviors in the open field test and depression-like behaviors in the tail suspension test. The immunochemistry showed that MD reduced OT immunoreactive neuron numbers in the hypothalamic paraventricular nucleus but increased OTR levels in the LHbM; EE increased CRH levels in the LHbM but decreased OTR levels in the LHbM. The additive effects of EE and MD maintained the behavioral parameters, OT-ir neuronal numbers, CRH levels, and OTR levels similar to the additive of non-MD and non-EE. The correlation analysis showed that CRH levels correlated with synaptic connection levels, OTR levels correlated with nucleus densities, and ERß levels correlated with Nissl body levels and body weights in female mice. Neither MD nor EE affected ERß levels in the LHbM. Together, the study revealed the relationships between behaviors and neuroendocrine and neuronal alterations in female LHbM and the effects of experiences including MD and EE on them.