Quantitative evaluation of choroidal and retinal microvasculature post-alcohol consumption: A pilot study.

PURPOSE: The aim of this study was to assess the impact of acute, heavy alcohol consumption on the ocular microvasculature, providing insight into the largely unexplored response of microvascular structures to excessive drinking. METHODS: Healthy volunteers in this prospective pilot study were tasked with consuming spirits, wine, and water at different times. Alcohol intake was measured according to body weight (g/kg). The ocular microvascular parameters primarily including choroidal volume (CV) and choroidal vessel volume (CVV) reflecting arteriolovenularity, and choroidal capillary density (CCD) reflecting capillary, were evaluated using swept-source optical coherence tomography angiography at baseline and 0.5-, 1-, 2-, and 3-hour post-consumption. RESULTS: A total of 34 eyes underwent 170 successful examinations in this study. After consuming spirits or wine, we observed significant decreases in CV and CVV values (all P < 0.01 for 0.5-, 1-, 2-, and 3-hour post-consumption), along with significant increase in CCD (P < 0.05 at 0.5-, 1-, 2-hour post-spirits consumption and 1-hour post-wine consumption). The most pronounced changes occurred 1-hour after spirits or wine consumption (all P < 0.001 in both univariate and multivariate model). However, post-consumption changes in the ocular microvasculature showed no significant differences between spirits and wine (P > 0.05). Additionally, no significant differences were observed in any parameters after water intake (all P > 0.05). CONCLUSIONS: Excessive alcohol consumption leads to ocular arteriolovenular vasoconstriction and capillary vasodilation, most evident 1-hour post-consumption of spirits and wine. Our research provides insight into alcohol's immediate ocular microvascular effects, hinting at systemic microvascular effects.

Single cell transcriptome analysis identified a unique neutrophil type associated with Alzheimer's disease.

BACKGROUND: Neutrophils play an essential role in Alzheimer's disease (AD) pathology. However, the extent of their heterogeneity remains poorly explored, particularly in the context of developing novel therapies targeting these cells. RESULTS: We investigate the population structure of neutrophils purified from peripheral blood samples of AD mice. Utilizing single cell RNA sequencing, we comprehensively map neutrophil populations into six distinct clusters and find that the Neu-5 subset is specially enriched in AD mice. This subset exhibits fewer specific granules and a lower mature score. Gene ontology (GO) analysis reveals that genes involved in cytokine-mediated signaling are downregulated in the Neu-5 cluster. Furthermore, we identify the Ccrl2 gene is specifically upregulated in this subgroup, which is confirmed by flow cytometry in AD mice. Finally, immunohistochemical staining indicates that CCRL2 protein is increased in the brains of AD mice. CONCLUSIONS: We identify a unique CCRL2 positive neutrophil cluster, that is specifically enriched in the peripheral blood of AD mice.

Epiretinal Macrophage-like Cells on Optical Coherence Tomography: Potential Inflammatory Imaging Biomarker of Severity in Diabetic Retinopathy.

PURPOSE: To investigate the clinical value of epiretinal macrophage-like cells (eMLC) in different stages of diabetic retinopathy (DR), including diabetic macular edema (DME). METHODS: One hundred and seventy-six eyes of 176 patients, including 31 diabetes eyes without retinopathy (NDR), 24 with mild non-proliferative DR (NPDR), 37 with moderate NPDR, 32 with severe NPDR, and 52 with proliferative DR (PDR), were compared to 30 healthy controls. The optic nerve head and macular region were examined using en face optical coherence tomography (OCT) and OCT angiography. A previously described technique was employed to measure the eMLCs on the inner limiting membrane. RESULTS: The optic nerve head (ONH) and macular eMLC densities increased with worsening DR stage and were higher in moderate, severe NPDR and PDR, especially in eyes with DME (all adjusted p<0.01). The ONH and macular eMLC densities in the DME groups were higher than those in their corresponding non-DME groups at the same DR stage (all p<0.05). The average macular thickness was correlated with macular eMLC density (standardized ß=0.661, p<0.001) in patients with diabetes. The proportion of eyes with larger and plumper eMLCs increased with worsening DR and was higher in moderate, severe NPDR, PDR and eyes with DME (p=0.018, p<0.001, p<0.001 and p<0.001 respectively). CONCLUSIONS: Increased density along with morphological changes of eMLCs are observed beginning with moderate NPDR, and correlate with the progression of DR, including DME.

SOLITARY PUNCTATE CHORIORETINITIS: A Unique Subtype of Punctate Inner Choroidopathy.

PURPOSE: To describe a case series of a special subtype of punctate inner choroidopathy with solitary lesions in the macular area and named solitary punctate chorioretinitis. METHODS: This retrospective observational study clinically evaluated 12 eyes from 12 patients diagnosed as punctate inner choroidopathy with solitary lesions. Demographic data and multimodal imaging features were analyzed for the included patients. RESULTS: All the included patients were Chinese and of Han ethnicity. The median age of the included patients was 29.5 years (range: 25-40 years). Most patients (11/12, 91.67%) were myopic, with median refraction errors of -4.4 diopters (D) (range: -8.5 to 0 D). Solitary chorioretinitis lesions were yellow‒white and appeared hyperfluorescent during the entire phase of fundus fluorescein angiography without leakage (9/12, 75%) and hypofluorescent on indocyanine green angiography (11/11, 100%). On spectral domain optical coherence tomography, active inflammatory lesions appeared as isolated, heterogeneous, moderately reflective material at the outer retina (10/12, 83.33%) in the fovea or parafoveal region with disruption of the outer retinal layers. When the inflammatory lesions regressed, the moderately reflective materials in the outer retina were absorbed or regressed with outer retinal tissue loss. Additional sequelae of lesion regression included focal choroidal excavation and intraretinal cystoid space. Secondary choroidal neovascularization was noticed in 2 eyes (2/12, 16.67%). CONCLUSION: Solitary punctate chorioretinitis is a rare and unique subtype of punctate inner choroidopathy. Solitary punctate chorioretinitis may also be an unrecognized etiology of some forms of focal choroidal excavation and idiopathic choroidal neovascularization.

Regulation of Neurotransmitter Release by Amyloid Precursor Protein Through Synapsin Phosphorylation.

Abnormal processing of amyloid precursor protein (APP) and aggregation of the Aß peptide are known to play a key role in the pathogenesis of Alzheimer disease, but the function of endogenous APP under normal physiological conditions remains poorly understood. In this study, we investigated presynaptic changes in APP knockout (KO) mice. We demonstrate that both sucrose-induced neurotransmission and synaptic depletion in response to high frequency stimulation are significantly enhanced in APP KO compared to wild type littermates. In addition, the level of phosphorylated forms of synapsins, but not total synapsins, is elevated in the KO mice. Furthermore, we show that the inhibition of L-type calcium channels normalizes phosphorylated synapsins and slows down the high frequency induced synaptic depletion in APP KO mice. These results suggest a new mechanism by which APP regulates synaptic vesicle dynamics through synapsin-dependent phosphorylation.

Antibiotic use in rural China: a cross-sectional survey of knowledge, attitudes and self-reported practices among caregivers in Shandong province.

BACKGROUND: To improve antibiotic use globally, we must deepen our understanding of the public's knowledge, attitudes and practices (KAP) concerning antibiotics. Children are frequent users of antibiotics, and their caregivers play important roles in determining how antibiotics are used. The purpose of this study was to describe caregivers' KAP in a rural province in eastern China, and to identify socio-demographic factors associated with inappropriate antibiotic use. METHODS: A cross-sectional questionnaire based survey was conducted in 12 villages in one county in Shandong Province. A total of 727 individuals who were the primary day-to-day caregiver for a child aged 0-7 years were randomly selected and invited to participate. All caregivers were surveyed face-to-face using a semi-structured questionnaire focusing on the use of antibiotics in children. RESULTS: Almost all invited caregivers (99.3 %) completed the questionnaire in full. Caregivers expressed high levels of over-expectation for antibiotics for common childhood symptoms, stating that antibiotics were always or usually necessary when a child has a fever (46 %) or dry cough (42 %). Most caregivers (93 %) were aware that they should follow the doctor's advice when giving their children antibiotics. Many, however, reported that they had previously deviated from advice; this was most commonly through using antibiotics intermittently rather than regularly, but also by increasing and decreasing doses. Caregivers that were older and that had less formal education had higher levels of self-reported adherence (p < 0.01). A third of caregivers admitted to storing leftover antibiotics at home, and almost all of these caregivers (97 %) had used the antibiotics on a second occasion for their child. CONCLUSION: We have identified important gaps in knowledge, attitudes and practices concerning antibiotics among this rural population of caregivers. There is a clear need for multifaceted interventions that target village doctors, to improve prescribing and communication, as well as the general public, to improve health-seeking behaviours and promote responsible individual use of antibiotics.

Analyzing Formation and Absorption of Avascular Subretinal Hyperreflective Material in nAMD from OCTA-Based Insights.

PURPOSE: To investigate the formation and absorption of avascular subretinal hyperreflective material (avSHRM) in neovascular age-related macular degeneration (nAMD) based on optical coherence tomography angiography (OCTA) characteristics. DESIGN: Prospective cohort study METHODS: This study included patients with treatment-naïve nAMD and followed up for 3 months. Subjects were classified into avSHRM group and non-avSHRM group based on the presence of avSHRM at baseline. Quantitative OCTA characteristics including explant area, perimeter, vessel area, density, length, junctions, endpoints, lacunarity, maximum vessel caliber, vessel dispersion, and fractal dimension were assessed, three-dimensional volume and optical density ratio (ODR) of avSHRM were measured. Comparison analyses, correlate coefficients and regression models were applied to explore factors associated with avSHRM formation and absorption. RESULTS: 88 eyes from 88 patients (39 females) were enrolled. Compared to non-avSHRM group, avSHRM group exhibit a more intricate vasculature, characterized by higher value of macular neovascularization (MNV) perimeter, vessel area, total vessel length, total number of junctions and total number of endpoints (all P < 0.05), as well as the maximum vessel caliber (P < 0.001). In the multivariate model, which has been adjusted for age, gender, and types of medications, avSHRM absorption was correlated with baseline average vessel length, maximum vessel caliber and avSHRM ODR (standardized ß = 0.274, -0.367 and -0.334; P = 0.049, 0.010 and 0.018, respectively), with an adjusted R² of 0.453. CONCLUSION: Quantitative OCTA measurements can be utilized for assessing the dynamics of avSHRM in nAMD. Patients with more complex vasculature are at a higher risk of avSHRM formation. Average vessel length, maximum vessel diameter and avSHRM ODR play a role in its absorption.

A Novel Exploration of the Choroidal Vortex Vein System: Incidence and Characteristics of Posterior Vortex Veins in Healthy Eyes.

Purpose: The purpose of this study was to investigate the incidence and characteristics of posterior vortex veins (PVVs) in healthy eyes and explore their relationship with age and refractive status. Methods: This retrospective cross-sectional analysis encompassed 510 eyes from 255 consecutive healthy participants. Wide-field optical coherence tomography angiography (WF-OCTA) imaging was used to assess the presence of PVVs. Eyes were classified according to refractive status (emmetropia, low and moderate myopia, and high myopia) and age (minors and adults). The incidence and characteristics of eyes with PVVs were analyzed. Results: Participants (mean age = 30.60 ± 21.12 years, 47.4% men) showed a mean refractive error of -2.83 ± 3.10 diopters (D; range = -12.00 to +0.75). PVVs were observed in 16.1% (82/510) of eyes. Of these, 39% (32/82) had PVVs in one eye and 61% (50/82) in both eyes. The mean number of PVVs per eye was 1.65 ± 1.05 (range = 1-6). PVVs are mainly around the optic disc (78%, 64/82) of eyes with PVVs and less in the macular area (6.1%, 5/82) or elsewhere (15.9%, 13/82). PVV incidence correlated with refractive status: 10.3% (22/213) in emmetropia, 16.6% (31/187) in low and moderate myopia, and 26.4% (29/110) in high myopia (P = 0.001), but not with age. Refractive status was the key predictor of PVV occurrence (odds ratio [OR] = 1.45, 95% confidence interval [CI] = 1.02-2.06, P = 0.038). Conclusions: This study confirms PVVs' presence in healthy eyes, highlighting their inherent existence and susceptibility to alterations due to refractive conditions. These findings enhance our understanding of the vortex vein system and its distribution within the eyes.

Diurnal Variation in Choroidal Parameters Among Healthy Subjects Using Wide-Field Swept-Source Optical Coherence Tomography Angiography.

Purpose: The purpose of this study was to evaluate the diurnal variation in choroidal parameters in a wide field area among healthy subjects and to identify correlations between choroidal luminal area and stromal area and various systemic factors. Methods: In this cross-sectional study, 42 eyes from 21 healthy participants (mean age = 32.4 ± 8.8 years) were examined using wide-field swept-source optical coherence tomography angiography (WF SS-OCTA, 24 mm × 20 mm). Measurements of choroidal parameters, including choroidal volume (CV), choroidal thickness (CT), choroidal vessel volume (CVV), and choroidal stromal volume (CSV), were taken at 8:00, 12:00, 18:00, and 22:00. Systemic factors, such as blood pressure and heart rate, were concurrently monitored. Results: Our study observed significant diurnal variations in the mean total CV, CT, CVV, and CSV, with minimum measurements around 12:00 (P < 0.001) and peak values at 22:00 (P < 0.001). Furthermore, changes in CV in specific regions were more closely associated with fluctuations in CVV than CSV in the same regions. No significant diurnal variations were found in systolic (P = 0.137) or diastolic blood pressure (P = 0.236), whereas significant variations were observed in the heart rate (P = 0.001). Conclusions: Our study reveals diurnal variations in choroidal parameters and their associations, emphasizing that changes in choroidal volume relate more to the luminal than the stromal area in vessel-rich regions. This enhances our understanding of choroidal-related ocular diseases. Translational Relevance: Regions with higher choroidal vasculature observed greater choroidal volume changes.

A prospective observation of influence of anti-VEGF on optic disc vasculature in nAMD patients.

BACKGROUND: This study aims to investigate the short-term changes in relatively normal retinal vessels following anti-vascular endothelial growth factor (anti-VEGF) therapy in nAMD patients, an area that currently represents a research gap. METHODS: In this prospective study, we enrolled patients newly diagnosed with neovascular age-related macular degeneration (nAMD) and received standardized monthly anti-VEGF therapy for three months. Follow-ups were conducted at baseline and 1-week, 1-month, 2-months and 3-months post first injection. Assessment indicators included radial peripapillary capillary vascular density (RPC-VD) and retinal nerve fiber layer (RNFL) thickness in different optic disk regions using optical coherence tomography angiography, as well as intraocular pressure (IOP). RESULTS: 68 nAMD patients (68 eyes) were included in this study. Significant reductions of RPC-VD and increases of RNFL thickness primarily in the nasal regions were observed 1-week post anti-VEGF (adjusted P < 0.05). Significant negative correlations were found between 1-week changes in RPC-VD and RNFL thickness in the nasal sectors (P < 0.05). From 1 to 3 months post-injection, RPC-VD and RNFL thickness essentially returned to baseline levels. Throughout the follow-up periods, IOP remained stable (P > 0.05). CONCLUSION: Anti-VEGF treatments transiently influence the relatively normal retinal vessels, which might lead to nerve fiber edema, predominantly on the nasal side of the optic disk.

Macrophage-like Cells Characterized by En Face Optical Coherence Tomography was Associated with Fluorescein Vascular Leakage in Behçet's Uveitis.

PURPOSE: To investigate the features of macrophage-like cell (MLC) characterized by en face optical coherence tomography (OCT) in Behçet's uveitis (BU). METHODS: The extent of fluorescein vascular leakage (FVL) was graded on a scale of 0-3 (0=none, 1=mild, 2=moderate, 3=severe) for the optic nerve head (ONH), macula and peripheral retina. The 3µm en face OCT slabs on inner limiting membrane of ONH or macular region was used to visualize the MLCs. RESULTS: The MLC densities of BU group in ONH and macular region were significantly higher than the control group (both p<0.001). The ONH and macular MLC density were significantly higher in eyes with higher FVL grade and they were positively correlated with FVL score (all p<0.001). CONCLUSION: MLC density was elevated in Behçet's uveitis and it may serve as a noninvasive indicator for the severity of fluorescein leakage and retinal inflammation in Behcet's uveitis.

Choroidal Vein Alterations in Pachychoroid Disease With Choroidal Vascular Hyperpermeability: Evaluated by Wide-Field Indocyanine Green Angiography.

Purpose: The purpose of this study was to investigate choroidal vein (ChV) morphological features in pachychoroid disease (PCD) with choroidal vascular hyperpermeability (CVH). Methods: This retrospective study assessed subfoveal choroidal thickness (SFCT) and CVH area numbers and locations of recruited patients with PCD using multimodal images. ChV alteration patterns, including fusiform, bulbosity, sausaging, confluence, and anastomoses, as well as asymmetric ChVs, dominant ChVs, and non-dominant ChVs, were evaluated using wide-field indocyanine green angiograms. Results: Of 68 PCD eyes from 35 patients (mean age: 46.16 ± 6.28 years, 71.4% men), 2.9% had uncomplicated pachychoroid, 32.4% had pachychoroid pigment epitheliopathy (PPE), 55.9% central serous chorioretinopathy (CSC), and 8.8% pachychoroid neovasculopathy (PNV). Mean SFCT was 468.65 ± 131.40 µm. Among 419 CVH areas, ChV fusiform, ChV bulbosity, and ChV sausaging accounted for 35.8%, 35.1%, and 29.1%, respectively; 21.2% had ChV confluence and 11.9% had ChV anastomoses. At CVH areas, 13.1% had retinal pigment epithelium (RPE) leakage. ChV fusiform is steadily declining (37.4%, 36.8%, and 22.9%, respectively), and ChV sausaging, ChV anastomoses, and ChV confluence are increased gradually in the PPE, CSC, and PNV groups (21.4%, 30.0%, and 37.1%; 11.4%, 11.1%, and 20.0%; and 19.8%, 20.9%, and 28.6%, respectively). Dominant ChVs had higher CVH area numbers than non-dominant ChVs in the PPE and CSC groups (P = 0.010, P = 0.001). Conclusions: Different patterns of ChV alterations, including the newly identified ChV confluence, are commonly present at CVH areas in PCD. The CVH areas in PCD eyes are primarily located within the dominant ChVs. These findings provide crucial evidence for advancing our understanding of the underlying mechanisms of PCD pathogenesis.

Characterizing neurotrophic factor-induced synaptic growth in primary mouse neuronal cultures.

Neurotrophic factors and their signaling cascades play important roles in synaptic growth, which can be investigated in cultured primary neurons to better control the concentrations and timing of neurotrophic factor treatment. Here, we provide a protocol detailing the preparation of cultured primary mouse neurons and the neurotrophic factor treatment. We then describe electrophysiological recording of synaptic transmission, immunocytochemistry of AMPA receptor expression, and imaging analysis of dendritic spines. This platform enables characterization of synaptic growth at functional and morphological levels. For complete details on the use and execution of this profile, please refer to Zhou et al. (2021).

The Role of Neutrophil Extracellular Traps in Lipopolysaccharide-Induced Depression-like Behaviors in Mice.

Peripheral inflammation plays a key role in the development of depression-like behaviors. However, the mechanisms underlying these effects remain largely unknown. Here, we found that the level of citrullinated histone H3 (cit-H3) significantly increased in the plasma of wildtype mice treated with lipopolysaccharide (LPS), which indicated that neutrophil extracellular traps (NETs) were formed. Moreover, the LPS-induced depression-like and asocial behaviors were significantly alleviated in the mice deficient of NETs. Mechanistically, NETs formation aggravated peripheral inflammation by increasing the concentrations of TNF-α, IL-1ß and IL-6 in plasma, which are major proinflammatory cytokines that can enter the brain, resulting in microglia activation and reduced astrocytes. Following this, increased TNF-α and IL-1ß were released into brain, inducing neuroinflammation and finally depression-like behaviors. Prohibiting NETs by PAD4 ablation significantly prevented LPS-induced microglia activation and the loss of astrocytes. Our results propose the role for peripheral NETs in LPS-induced depression-like behavior, and that NETs might be a potential target to prevent inflammation-induced major depressive disorder.

NGPF2 triggers synaptic scaling up through ALK-LIMK-cofilin-mediated mechanisms.

Synaptic scaling is an extensively studied form of homeostatic plasticity critically involved in various brain functions. Although it is accepted that synaptic scaling is expressed through the postsynaptic accumulation of AMPA receptors (AMPARs), the induction mechanism remains elusive. In this study, we show that TTX treatment induces rapid but transient release of the neurite growth-promoting factor 2 (NGPF2), and this release is necessary and sufficient for TTX-induced scaling up. In addition, we show that inhibition of the anaplastic lymphoma kinase (ALK)-LIMK-cofilin signaling pathway blocks TTX- and NGPF2-induced synaptic scaling up. Furthermore, we show that TTX-induced release of NGPF2 is protein synthesis dependent and requires fragile X mental retardation protein 1 (FMRP1). These results indicate that activity blockade induces NGPF2 synthesis and release to trigger synaptic scaling up through LIMK-cofilin-dependent actin reorganization, spine enlargement, and stabilization of AMPARs at the synapse.

Neonatal exposure to ketamine disrupts developmental synapse unsilencing and predisposes adult mice for stressor-evoked anxiety.

Accumulating evidence suggests long-lasting impairments in brain development and cognition caused by neonatal exposure to general anesthetics. To date, very little is known about potential abnormal psychiatric manifestations attributable to neonatal anesthesia. In this study, we used ketamine to induce anesthesia in neonatal mice. By applying mild stressors one day before behavioral tests, we found that adult mice exhibit significant anxiety-like behaviors that were indistinguishable at basal level. Recruitment of AMPA (a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) type glutamate receptors into silent synapses is a prominent cellular process during neonatal neurodevelopment. We found that exposure to ketamine significantly disrupted synapse unsilencing, and impaired the expression of unsilencing-mediated long-term potentiation (LTP). Pharmacologically enhancement of neural activities by AMPAkine drug CX546 [1-(1,4-benzodioxan-6-ylcarbonyl) piperidine] effectively rescued disrupted developmental synapse unsilencing and LTP at neonatal age, and prevented stressor-evoked anxiety-like behaviors in adult mice. Together, our results indicate that neonatal exposure to ketamine may predispose individuals for psychiatric conditions via disrupting synapse unsilencing, and potentiation of neural activities during the anesthesia-recovery period may be an effective approach to manage adverse effects on brain development. This article is part of the special issue on 'Stress, Addiction and Plasticity'.

Expression of the erythropoietin receptor in patients with proliferative diabetic retinopathy and its correlation with postoperative visual prognosis.

BACKGROUND: Proliferative diabetic retinopathy (PDR) is a leading cause of blindness. This study aimed to analyze the expression of the erythropoietin receptor (EpoR) in patients with PDR and its correlation with postoperative visual prognosis. METHODS: Between May 2016 and May 2017, 89 patients who underwent vitreoretinal surgery (VRS) in Affiliated Hospital of North Sichuan Medical College were enrolled. Among them, 45 patients (52 eyes) with PDR and 44 patients (50 eyes) with retinal vein occlusion (RVO) made up the study group and the control group, respectively. All patients received 25G standard flattened three-channel lens-preserving VRS; all procedures were performed by the same physician. Recovery and change in best corrected visual acuity (BCVA) were observed. Subsequently, the patients were divided into group A (improved vision) and group B (no improvement in vision). The integrated optical density (IOD) value of EpoR expression among the groups were compared. Pearson's correlation analysis was used to analyze the correlation between the IOD values of EpoR and the change in visual acuity after surgery for PDR. RESULTS: The IOD value of EpoR in the study group was higher than that in the control group (P<0.05). The postoperative BCVA of the PDR patients was significantly higher than that before surgery (≥0.1 vs. ≤0.02, P<0.05). Of the 45 PDR patients (52 eyes), 34 patients (39 eyes) had improved visual acuity after surgery (group A), while 11 patients (13 eyes) experienced no improvement (group B). The IOD value of EpoR expression in group B was higher than that in group A (P<0.05). Pearson's correlation analysis showed that the IOD value of EpoR expression were positively correlated with the recovery. CONCLUSIONS: EpoR is expressed at a high level in PDR patients. The expression level of EpoR in the epiretinal membrane of PDR patients is positively correlated with the prognosis of postoperative vision. Therefore, EpoR has promise as a prognostic biomarker and a potential therapeutic target for PDR.

Cdk7 Is Required for Activity-Dependent Neuronal Gene Expression, Long-Lasting Synaptic Plasticity and Long-Term Memory.

In the brain, de novo gene expression driven by learning-associated neuronal activities is critical for the formation of long-term memories. However, the signaling machinery mediating neuronal activity-induced gene expression, especially the rapid transcription of immediate-early genes (IEGs) remains unclear. Cyclin-dependent kinases (Cdks) are a family of serine/threonine kinases that have been firmly established as key regulators of transcription processes underling coordinated cell cycle entry and sequential progression in nearly all types of proliferative cells. Cdk7 is a subunit of transcriptional initiation factor II-H (TFIIH) and the only known Cdk-activating kinase (CAK) in metazoans. Recent studies using a novel Cdk7 specific covalent inhibitor, THZ1, revealed important roles of Cdk7 in transcription regulation in cancer cells. However, whether Cdk7 plays a role in the regulation of transcription in neurons remains unknown. In this study, we present evidence demonstrating that, in post-mitotic neurons, Cdk7 activity is positively correlated with neuronal activities in cultured primary neurons, acute hippocampal slices and in the brain. Cdk7 inhibition by THZ1 significantly suppressed mRNA levels of IEGs, selectively impaired long-lasting synaptic plasticity induced by 4 trains of high frequency stimulation (HFS) and prevented the formation of long-term memories.

Transient inhibition of LIMKs significantly attenuated central sensitization and delayed the development of chronic pain.

Central sensitization represents a key mechanism mediating chronic pain, a major clinical problem lacking effective treatment options. LIM-domain kinases (LIMKs) selectively regulate several substrates, e.g. cofilin and cAMP response element-binding protein (CREB), that profoundly affect neural activities, such as synaptogenesis and gene expression, thus critical in the consolidation of long-term synaptic potentiation and memory in the brain. In this study, we demonstrate that LIMK deficiency significantly impaired the development of multiple forms of chronic pain. Mechanistic studies focusing on spared nerve injury (SNI) model reveal a pivotal role of LIMKs in the up-regulation of spontaneous excitatory synaptic transmission and synaptogenesis after pain induction. Depending on the pain induction methods, LIMKs can be transiently activated with distinct time courses. Accordingly, pharmacological inhibition of LIMKs targeting this critical period remarkably attenuated central sensitization in the spinal cord and alleviated pain behaviors. We propose selectively targeting LIMKs during their activation phase as a potential therapeutic strategy for clinical management of chronic pain, especially for chronic pain with predictable onset and development time courses, such as chronic post-surgical pain (PSP).