Intermittent Theta-Burst Stimulation for Stroke: Primary Motor Cortex Versus Cerebellar Stimulation: A Randomized Sham-Controlled Trial.

BACKGROUND: Stroke survivors with impaired balance and motor function tend to have relatively poor functional outcomes. The cerebellum and primary motor cortex (M1) have been suggested as targets for neuromodulation of balance and motor recovery after stroke. This study aimed to compare the efficacy and safety of intermittent theta-burst stimulation (iTBS) to the cerebellum or M1 on balance and motor recovery in patients with stroke. METHODS: In this randomized, double-blind, sham-controlled clinical trial, patients with subacute stroke were randomly divided into 3 groups: M1-, cerebellar-, and sham-iTBS (n=12 per group; 15 sessions, 3 weeks). All outcomes were evaluated before intervention (T0), after 1 week of intervention (T1), after 3 weeks of intervention (T2), and at follow-up (T3). The primary outcome was the Berg balance scale score at T2. Secondary outcomes include the Fugl-Meyer assessment scale for lower extremities, the trunk impairment scale, the Barthel index, the modified Rankin Scale, the functional ambulation categories, and cortical excitability. RESULTS: A total of 167 inpatients were screened, 36 patients (age, 57.50±2.41 years; 10 women, 12 ischemic) were enrolled between December 2020 and January 2023. At T2, M1- or cerebellar-iTBS significantly improved Berg balance scale scores by 10.7 points ([95% CI, 2.7-18.6], P=0.009) and 14.2 points ([95% CI, 1.2-27.2], P=0.032) compared with the sham-iTBS group. Moreover, the cerebellar-iTBS group showed a significantly greater improvement in Fugl-Meyer assessment scale for lower extremities scores by 5.6 points than the M1-iTBS ([95% CI, 0.3-10.9], P=0.037) and by 7.8 points than the sham-iTBS ([95% CI, 1.1-14.5], P=0.021) groups at T2. The motor-evoked potential amplitudes of the M1- and cerebellar-iTBS groups were higher than those of the sham-iTBS group (P<0.001). CONCLUSIONS: Both M1- and cerebellar-iTBS could improve balance function. Moreover, cerebellar-iTBS, but not M1-iTBS, induced significant effects on motor recovery. Thus, cerebellar-iTBS may be a valuable new therapeutic option in stroke rehabilitation programs. REGISTRATION: URL: https://www.chictr.org.cn/; Unique identifier: ChiCTR2100047002.

IL2-inducible T-cell kinase inhibitor ibrutinib reduces symptoms and Th2 differentiation in mouse allergic-rhinitis model.

Th2 and Th17 immune response contribute to allergic rhinitis (AR) development. Targeting Th2 and Th17 response has been shown to ameliorate AR. Ibrutinib is an inhibitor for IL2-inducible T-cell kinase, which can promote Th2 and Th17 immune response. We sought to investigate the effect of ibrutinib on AR and the underlying mechanisms. We established house dust mite-induced AR mouse model and treated AR mice with ibrutinib. The symptoms of AR, serum level of immunoglobulin E, percentage of Th1, Th2, Th17, and Treg in nasal lymphoid tissues were monitored. We also established in vitro T cell differentiation cell culture model. The T cells were treated with ibrutinib and the expression of specific transcriptional factors and cytokines was measured. The activation of PLC-γ1/calcium/NFAT2 signaling pathway was detected. Ibrutinib treatment had no effects on the development of lymphocytes and myeloid cells, but alleviated AR symptoms and decreased Th2 cell population in nasal lymphoid tissue. Meanwhile, iburitnib suppressed Th2 and Th17 differentiation in vitro. Moreover, iburitnib prevented phosphorylation of PLC-γ1and nuclear translocation of NFAT2 in Th2 cells. Our results suggested that ibrutinib could ameliorate AR symptoms through suppression of Th2 differentiation in AR mouse model.

The calcimedin annexin A3 displays tumor-promoting effect in esophageal squamous cell carcinoma by activating NF-κB signaling.

Esophageal squamous cell carcinoma (ESCC) is one of the lethal malignancies commonly found in the eastern world, with overall five-year survival rates less than 25%. The present study aimed to investigate the biological function of annexin A3 (ANXA3) in ESCC cell proliferation. The mRNA and protein levels of ANXA3 in ESCC tissues and cell lines were determined by real-time PCR and Western blot, respectively. Lentiviral transduction was applied to overexpress or reduce ANXA3 expression in ESCC cell lines. The effect of ANXA3 on ESCC cell proliferation was evaluated by cell-counting kit-8 assay in vitro and tumor-bearing animal model in vivo. We found that ANXA3 was substantially upregulated in ESCC tissues compared to adjacent normal tissues as well as ESCC cell lines compared to normal esophageal endothelial cells. Suppression of ANXA3 significantly inhibited ESCC cell proliferation in vitro and tumor growth in vivo. We further revealed that NF-κB was involved in ANXA3-mediated ESCC cell proliferation. Our results suggest that ANXA3 acts as an oncogene in ESCC, and targeting ANXA3 or NF-κB may serve as potential therapeutic strategies for patients with ESCC.

The projections from the anterior cingulate cortex to the nucleus accumbens and ventral tegmental area contribute to neuropathic pain-evoked aversion in rats.

Although the anterior cingulate cortex (ACC) plays a vital role in neuropathic pain-related aversion, the underlying mechanisms haven't been fully studied. The mesolimbic dopamine system encodes reward and aversion, and participates in the exacerbation of chronic pain. Therefore, we investigated whether the ACC modulates aversion to neuropathic pain via control of the mesolimbic dopamine system, in a rat model of chronic constriction injury (CCI) to the sciatic nerve. Using anterograde and retrograde tracings, we confirmed that a subgroup of ACC neurons projected to the nucleus accumbens (NAc) and ventral tegmental area (VTA), which are two crucial nodes of the mesolimbic dopamine system. Combining electrophysiology in juvenile rats 7 days post-CCI, we found that the NAc/VTA-projecting neurons were hyperexcitable after CCI. Chemogenetic inhibition of these projections induced conditioned place preference in young adult rats 10-14 days post-CCI, without modulating the evoked pain threshold, whereas activation of these projections in sham rats mimicked aversive behavior. Furthermore, the function of the ACC projections was probably mediated by NAc D2-type medium spiny neurons and VTA GABAergic neurons. Taken together, our findings suggest that projections from the ACC to the NAc and VTA mediate neuropathic pain-related aversive behavior.

Neurotrophin receptor p75 mediates amyloid ß-induced tau pathology.

Neurofibrillary tangles of hyperphosphorylated tau protein (p-tau) are a key pathological feature of Alzheimer's disease (AD). Tau phosphorylation is suggested to be secondary to amyloid-beta (Aß) accumulation. However, the mechanism by which Aß induces tau phosphorylation in neurons remains unclear. Neurotrophin receptor p75 (p75NTR) is a receptor for Aß and mediates Aß neurotoxicity, implying that p75NTR may mediate Aß-induced tau phosphorylation in AD. Here, we showed that Aß-induced tau hyperphosphorylation and neurodegeneration, including tau phosphorylation, synaptic disorder and neuronal loss, in the brains of both male wild-type (Wt) mice and male P301L transgenic mice (a mouse model of human tauopathy) were alleviated by genetic knockout of p75NTR in the both mouse models. We further confirmed that the activation or inhibition of cyclin-dependent kinase 5 (CDK5) and glycogen synthase kinase-3ß (GSK3ß) significantly changed Aß/p75NTR-mediated p-tau levels in neurons. Treatment of male P301L mice with soluble p75NTR extracellular domain (p75ECD-Fc), which antagonizes the binding of Aß to p75NTR, suppressed tau hyperphosphorylation. Taken together, our findings suggest that p75NTR meditates Aß-induced tau pathology and is a potential druggable target for AD and other tauopathies.

The ProNGF/p75NTR pathway induces tau pathology and is a therapeutic target for FTLD-tau.

Tau pathology is characterized as a form of frontotemporal lobar degeneration (FTLD) known as FTLD-tau. The underlying pathogenic mechanisms are not known and no therapeutic interventions are currently available. Here, we report that the neurotrophin receptor p75NTR plays a critical role in the pathogenesis of FTLD-tau. The expression of p75NTR and the precursor of nerve growth factor (proNGF) were increased in the brains of FTLD-tau patients and mice (P301L transgenic). ProNGF-induced tau phosphorylation via p75NTR in vitro, which was associated with the AKT/glycogen synthase kinase (GSK)3ß pathway. Genetic reduction of p75NTR in P301L mice rescued the memory deficits, alleviated tau hyperphosphorylation and restored the activity of the AKT/GSK3ß pathway. Treatment of the P301L mice with the soluble p75NTR extracellular domain (p75ECD-Fc), which can antagonize neurotoxic ligands of p75NTR, effectively improved memory behavior and suppressed tau pathology. This suggests that p75NTR plays a crucial role in tau paGSKthology and represents a potential druggable target for FTLD-tau and related tauopathies.

Inhibition of Metabotropic Glutamate Receptor Subtype 1 Alters the Excitability of the Commissural Pyramidal Neuron in the Rat Anterior Cingulate Cortex after Chronic Constriction Injury to the Sciatic Nerve.

BACKGROUND: Inhibition of the metabotropic glutamate receptor subtype 1 in the anterior cingulate cortex has an analgesic effect during sustained nociceptive hypersensitivity. However, the specific changes in different subtypes of anterior cingulate cortex layer 5 pyramidal neurons, as well as the distinct effect of metabotropic glutamate receptor subtype 1 inhibition on different neuronal subtypes, have not been well studied. METHODS: Retrograde labeling combined with immunofluorescence, whole cell clamp recording, and behavioral tests combined with RNA interference were performed in a rat model of chronic constriction injury to the sciatic nerve. RESULTS: Commissural layer 5 pyramidal neurons (projecting to the contralateral cortex) existed in the anterior cingulate cortex. The voltage-gated potassium channel subunit 2-mediated current in these neurons were substantially reduced after chronic constriction injury (current densities at +30 mV for the sham, and chronic constriction injury neurons were [mean ± SD] 10.22 ± 3.42 pA/pF vs. 5.58 ± 2.71 pA/pF, respectively; n = 11; P < 0.01), which increased the spike width and fast afterhyperpolarization potential, resulting in hyperexcitability. Inhibition of metabotropic glutamate receptor subtype 1 alleviated the down-regulation of voltage-gated potassium channel subunit 2 currents (current density increased by 8.11 ± 3.22 pA/pF; n = 7; P < 0.01). Furthermore, knockdown of voltage-gated potassium channel subunit 2 current in the commissural neurons attenuated the analgesic effect of metabotropic glutamate receptor subtype 1 inhibition (n = 6 rats; P < 0.05). CONCLUSIONS: The effect of metabotropic glutamate receptor subtype 1 inhibition on commissural anterior cingulate cortex layer 5 pyramidal neurons is likely different with the modification of previously studied hyperpolarization-activated/cyclic nucleotide-gated channel-dependent neurons but relies on the alteration of voltage-gated potassium channel subunit 2 currents. These results will contribute to a better understanding of the therapeutic role of metabotropic glutamate receptor subtype 1 in chronic pain.

Event-related alpha power in early stage of facial expression processing in social anxiety: Influence of language context.

Accurate interpretation of the emotional information conveyed by others' facial expressions is crucial for social interactions. Event-related alpha power, measured by time-frequency analysis, is a frequently used EEG index of emotional information processing. However, it is still unclear how event-related alpha power varies in emotional information processing in social anxiety groups. In the present study, we recorded event-related potentials (ERPs) while participants from the social anxiety and healthy control groups viewed facial expressions (angry, happy, neutral) preceded by contextual sentences conveying either a positive or negative evaluation of the subject. The impact of context on facial expression processing in both groups of participants was explored by assessing behavioral ratings and event-related alpha power (0-200 ms after expression presentation). In comparison to the healthy control group, the social anxiety group exhibited significantly lower occipital alpha power in response to angry facial expressions in negative contexts and neutral facial expressions in positive contexts. The influence of language context on facial expression processing in individuals with social anxiety may occur at an early stage of processing.

Intermittent Theta Burst Stimulation Attenuates Cognitive Deficits and Alzheimer's Disease-Type Pathologies via ISCA1-Mediated Mitochondrial Modulation in APP/PS1 Mice.

Intermittent theta burst stimulation (iTBS), a time-saving and cost-effective repetitive transcranial magnetic stimulation regime, has been shown to improve cognition in patients with Alzheimer's disease (AD). However, the specific mechanism underlying iTBS-induced cognitive enhancement remains unknown. Previous studies suggested that mitochondrial functions are modulated by magnetic stimulation. Here, we showed that iTBS upregulates the expression of iron-sulfur cluster assembly 1 (ISCA1, an essential regulatory factor for mitochondrial respiration) in the brain of APP/PS1 mice. In vivo and in vitro studies revealed that iTBS modulates mitochondrial iron-sulfur cluster assembly to facilitate mitochondrial respiration and function, which is required for ISCA1. Moreover, iTBS rescues cognitive decline and attenuates AD-type pathologies in APP/PS1 mice. The present study uncovers a novel mechanism by which iTBS modulates mitochondrial respiration and function via ISCA1-mediated iron-sulfur cluster assembly to alleviate cognitive impairments and pathologies in AD. We provide the mechanistic target of iTBS that warrants its therapeutic potential for AD patients.

The long-term effects of intermittent theta burst stimulation on Alzheimer's disease-type pathologies in APP/PS1 mice.

Intermittent theta burst stimulation (iTBS), an emerging and highly efficient paradigm of repetitive transcranial magnetic stimulation (rTMS), has been demonstrated to mitigate cognitive impairment in Alzheimer's disease. Previous clinical studies have shown that the cognitive improvement of iTBS could last several weeks after treatment. Nonetheless, it is largely uncertain how the long-term effects of iTBS treatment are sustained. To investigate whether iTBS has a long-term effect on AD-type pathologies, 6-month-old APP/PS1 mice are administrated with 30 consecutive days of iTBS treatment. After a 2-month interval, morphological alterations in the brain are examined by immunohistochemistry and immunofluorescence staining, while levels of associated proteins are assessed by Western blot at the age of 9 months. We find that iTBS treatment significantly diminishes Aß burden in the cerebral cortex and hippocampus of APP/PS1 mice. Moreover, we observe that iTBS treatment inhibits the expression of BACE1 and elevates the level of IDE, suggesting that the reduction of Aß load could be attributed to the inhibition of Aß production and facilitation of Aß degradation. Furthermore, iTBS treatment attenuates neuroinflammation, neuronal apoptosis, and synaptic loss in APP/PS1 mice. Collectively, these data indicate that 1 month of iTBS treatment ameliorates pathologies in the brain of AD mice for at least 2 months. We provide the novel evidence that iTBS may exert after-effects on AD-type pathologies via inhibition of Aß production and facilitation of Aß degradation.

Solid-Phase Polymerization Using Anion-Exchange Resin Can Almost Completely Crosslink Hemoglobin to Prepare Hemoglobin-Based Oxygen Carriers.

Introduction: A limitation of hemoglobin-based oxygen carriers (HBOCs) as oxygen therapeutics is unpolymerized hemoglobin, which induces vasoconstriction leading to hypertension. The removal of unpolymerized hemoglobin from polymerized hemoglobin (PolyHb) is complex, expensive, and time-consuming. Methods: Herein, we developed a method to completely polymerize hemoglobin almost without unpolymerized hemoglobin. Hemoglobin was adsorbed on the anion-exchange resin Q Sepharose Fast Flow or DEAE Sepharose Fast Flow, and acetal, a crosslinker prepared from glutaraldehyde and ethylene glycol, was employed to polymerize the hemoglobin. The polymerization conditions, including reaction time, pH, resin type, and molar ratios of glutaraldehyde to ethylene glycol and hemoglobin to acetal, were optimized. The blood pressure and blood gas of mice injected with PolyHb were monitored as well. Results: The optimal polymerization condition of PolyHb was when the molar ratio of glutaraldehyde to ethylene glycol was 1:20, and the molar ratio of 10 mg/mL hemoglobin adsorbed on anion-exchange resin to glutaraldehyde was 1:300 for 60 min. Under optimized reactive conditions, hemoglobin was almost completely polymerized, with <1% hemoglobin remaining unpolymerized, and the molecular weight of PolyHb was more centrally distributed. Furthermore, hypertension was not induced in mice by PolyHb, and there were also no pathological changes observed in arterial oxygen, blood gas, electrolytes, and some metabolic indicators. Conclusion: The findings of this study indicate that the use of solid-phase polymerization and acetal is a highly effective and innovative approach to HBOCs, resulting in the almost completely polymerized hemoglobin. These results offer promising implications for the development of new methods for preparing HBOCs.

Adaptive backstepping sliding mode control of permanent magnet spherical motor based on disturbance observer.

This paper proposes an adaptive backstepping sliding mode control method based on a nonlinear disturbance observer (NDO) to solve the problem that the tracking performance of the motion system of a permanent magnet spherical motor (PMSpM) is degraded due to the influence of external nonlinear disturbance. First, the dynamic model of the PMSpM under the compound interference is established. Second, an NDO and an adaptive backstepping sliding mode controller are designed to compensate for the external disturbances and modeling uncertainties, and the stability of the closed-loop system using the proposed method is confirmed through the Lyapunov theorem. Then, compared with the results of proportion differentiation control and conventional sliding mode control, the simulation results show that the proposed method can significantly reduce input signal chattering and improve the trajectory tracking performance of the PMSpM. Finally, experimental results are provided to validate the effectiveness of the proposed method.

Activation of Dopamine D2 Receptors Alleviates Neuronal Hyperexcitability in the Lateral Entorhinal Cortex via Inhibition of HCN Current in a Rat Model of Chronic Inflammatory Pain.

Functional changes in synaptic transmission from the lateral entorhinal cortex to the dentate gyrus (LEC-DG) are considered responsible for the chronification of pain. However, the underlying alterations in fan cells, which are the predominant neurons in the LEC that project to the DG, remain elusive. Here, we investigated possible mechanisms using a rat model of complete Freund's adjuvant (CFA)-induced inflammatory pain. We found a substantial increase in hyperpolarization-activated/cyclic nucleotide-gated currents (Ih), which led to the hyperexcitability of LEC fan cells of CFA slices. This phenomenon was attenuated in CFA slices by activating dopamine D2, but not D1, receptors. Chemogenetic activation of the ventral tegmental area -LEC projection had a D2 receptor-dependent analgesic effect. Intra-LEC microinjection of a D2 receptor agonist also suppressed CFA-induced behavioral hypersensitivity, and this effect was attenuated by pre-activation of the Ih. Our findings suggest that down-regulating the excitability of LEC fan cells through activation of the dopamine D2 receptor may be a strategy for treating chronic inflammatory pain.

Influence of affective verbal context on emotional facial expression perception of social anxiety.

Previous studies have shown that the perception of ambiguous facial expressions for individuals with social anxiety was influenced by the affective verbal context. However, it is still unknown how emotional facial expressions are perceived by individuals with social anxiety in the context of the verbal context. In this study, we used event-related potentials (ERPs) technology to examine how individuals with social anxiety perceive emotional facial expressions in positive and negative contexts. The results showed that: (1) Within the negative verbal contexts, the amplitude of P1 induced by facial expressions in the social anxiety group was significantly higher than that induced by the healthy control group; The N170 amplitude induced by facial expressions in social anxiety group was less negative than that in the healthy control group, and was not affected by the context. (2) The social anxiety group had significantly higher LPP in negative contexts elicited by angry expressions than by happy expressions. This study proved that the perception of emotional facial expressions was influenced by top-down information in the early and late stages of visual perception for individuals with social anxiety.

p75NTR Ectodomain Ameliorates Cognitive Deficits and Pathologies in a Rapid Eye Movement Sleep Deprivation Mice Model.

The neurotrophin receptor p75 (p75NTR) is a circadian rhythm regulator and mediates cognitive deficits induced by sleep deprivation (SD). The soluble extracellular domain of p75NTR (p75ECD) has been shown to exert a neuroprotective function in Alzheimer's disease (AD) and depression animal models. Nevertheless, the role of p75ECD in SD-induced cognitive dysfunction is unclear. In the present study we administrated p75ECD-Fc (10, 3 mg/kg), a recombinant fusion protein of human p75ECD and fragment C of immunoglobulin IgG1, to treat mice via intraperitoneal injection. The results revealed that peripheral supplementation of high-dose p75ECD-Fc (10 mg/kg) recovered the balance between Aß and p75ECD in the hippocampus and rescued the cognitive deficits in SD mice. We also found that p75ECD-Fc ameliorated other pathologies induced by SD, including neuronal apoptosis, synaptic plasticity impairment and neuroinflammation. The current study suggests that p75ECD-Fc is a potential candidate for SD and peripheral supplementation of p75ECD-Fc may be a prospective preventive measure for cognitive decline in SD.

Spleen Tyrosine Kinase Mediates Microglial Activation in Mice With Diabetic Retinopathy.

Purpose: Diabetic retinopathy (DR) is a leading cause of blindness in developed countries, in which microglial activation is involved. However, the mechanism of microglial activation in DR remains largely unknown. Methods: We used Cx3cr1CreERT2; Sykfl/fl mice to knockout microglial spleen tyrosine kinase (Syk) in the retina of mice (cKO mice) after streptozotocin injection to induce diabetes. We also isolated primary retinal microglia from wild-type and cKO mice, respectively, to explore the role of microglial Syk in DR. Results: The deletion of microglial Syk in the retina of mice or in the primary retinal microglia inhibited microglial activation and inflammatory response, eventually leading to the improvement of DR by regulating the expressions of interferon regulatory factor 8 (Irf8) and Pu.1 both in vivo and in vitro. Conclusions: The deletion of microglial Syk in the retina effectively ameliorated microglial activation-induced DR, suggesting the potential of microglial Syk as a therapeutic target for DR. Translational Relevance: Microglial spleen tyrosine kinase might serve as a potential therapeutic target for diabetic retinopathy.

Parameter Optimization Analysis of Prolonged Analgesia Effect of tDCS on Neuropathic Pain Rats.

Background: Transcranial direct current stimulation (tDCS) is widely used to treat human nerve disorders and neuropathic pain by modulating the excitability of cortex. The effectiveness of tDCS is influenced by its stimulation parameters, but there have been no systematic studies to help guide the selection of different parameters. Objective: This study aims to assess the effects of tDCS of primary motor cortex (M1) on chronic neuropathic pain in rats and to test for the optimal parameter combinations for analgesia. Methods: Using the chronic neuropathic pain models of chronic constriction injury (CCI), we measured pain thresholds before and after anodal-tDCS (A-tDCS) using different parameter conditions, including stimulation intensity, stimulation time, intervention time and electrode located (ipsilateral or contralateral M1 of the ligated paw on male/female CCI models). Results: Following the application of A-tDCS over M1, we observed that the antinociceptive effects were depended on different parameters. First, we found that repetitive A-tDCS had a longer analgesic effect than single stimulus, and both ipsilateral-tDCS (ip-tDCS) and contralateral-tDCS (con-tDCS) produce a long-lasting analgesic effect on neuropathic pain. Second, the antinociceptive effects were intensity-dependent and time-dependent, high intensities worked better than low intensities and long stimulus durations worked better than short stimulus durations. Third, timing of the intervention after injury affected the stimulation outcome, early use of tDCS was an effective method to prevent the development of pain, and more frequent intervention induced more analgesia in CCI rats, finally, similar antinociceptive effects of con- and ip-tDCS were observed in both sexes of CCI rats. Conclusion: Optimized protocols of tDCS for treating antinociceptive effects were developed. These findings should be taken into consideration when using tDCS to produce analgesic effects in clinical applications.

Activation of mGluR1 contributes to neuronal hyperexcitability in the rat anterior cingulate cortex via inhibition of HCN channels.

Neuronal hyperexcitability in the anterior cingulate cortex (ACC) is considered as one of the most important pathological changes responsible for the chronification of neuropathic pain. However, the underlying mechanisms remain elusive. In the present study, we investigated the possible mechanisms using a rat model of chronic constriction injury (CCI) to the sciatic nerve. We found a substantial decrease in hyperpolarization-activated/cyclic nucleotide-gated (HCN) currents in layer 5 pyramidal neurons (L5 PNs) in ACC slices, which dramatically increased the excitability of these neurons. This effect could be mimicked in sham slices by activating group 1 metabotropic glutamate receptors, and be blocked in CCI slices by inhibiting metabotropic glutamate receptor subtype 1 (mGluR1). Next, the inhibition of HCN currents was reversed by a protein kinase C (PKC) inhibitor, followed by a reduced neuronal hyperexcitability. Furthermore, HCN channel subtype 1 (HCN1) level was significantly reduced after CCI, whereas mGluR1 level increased. These changes were mainly observed in L5 of the ACC, where HCN1 and mGluR1 were highly colocalized. For behavioral tests, intra-ACC microinjection of mGluR1-shRNA suppressed the CCI-induced behavioral hypersensitivity, particularly thermal hyperalgesia, but not aversive behavior, and this effect was attenuated by the pre-blockade of HCN channels. Taken together, the neuronal hyperexcitability of ACC L5 PNs likely results from an upregulation of mGluR1 and a downstream pathway involving PKC activation and a downregulation of HCN1 in the early phase of neuropathic pain. These alterations may at least in part contribute to the development of behavioral hypersensitivity in CCI rats.