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Abstract: Two types of acid-sensing ion channel (ASIC)-like currents in cultured rat hippocampal neurons were recorded and their characteristics were studied by using a whole-cell recording technique. The results revealed that the ASIC-like currents, induced by a quick drop of the extracellular pH, decayed with different time constants (τ) of 229 ± 16 (Type I) and 1209 ± 56ms (Type II). The ASIC-like currents displayed different sensitivities to extracellular proton (pH0.5 was 6.17 ± 0.04 for Type I and 5.70 ± 0.07 for Type II) and amiloride, a specific ASIC channel blocker (IC50 was 1.19 ± 0.37μM for Type I and 0.14 ± 0.02μM for Type II). Among all the 360 recorded neurons, ASIC-like currents were induced in 314 neurons (87.2%). In the neurons expressing ASICs, Type I currents were evoked from 269 neurons (85.7%) and Type II currents were induced only from 45 neurons (14.3%). As these ASIC-like currents presented various electrophysiological and pharmacological properties, further experiments should be conducted to decipher the complex subunit composition of ASICs in the hippocampus. [Copyright &y& Elsevier]

A response by Hua-Ying Liang, Ian H. Campbell, Charlotte A. Allen, Wei-Dong Sun, Ying-Weng Xie and Yuan-Qian Zhang to the letter to the editor about their article "The Age of the Potassic Alkaline Igneous Rocks Along the Ailao Shan-Red River Shear Zone: Implications for the Onset Age of Left-Lateral Shearing" in the 2007 issue is presented.

Hepatocellular carcinoma (HCC) is a familiar malignant tumor, and cepharanthine (CEP) was proven to prevent the malignant activity of multiple cancer cells, including HCC. However, there are few reports on the regulatory role of CEP in HCC. After treatment with CEP or/and JAK2/Stat3 inhibitor (AG490), the associative functions were assessed by MTT, wound healing, Trans well, and Hochest33342-PI double staining in HCC cells. Then the levels of CDK4, MMP-9, Bcl-2, p-JAK2/JAK2, and p-Stat3/Stat3 were monitored via western blot. Besides, the HCC xenograft model was constructed to verify the effects of CEP on tumor growth and the JAK/Stat3 pathway. CEP could restrain proliferation and metastasis and facilitate apoptosis in HCC cells. CEP also reduced Bcl-2 (anti-apoptosis), CDK4 (proliferation), and MMP-9 (invasion) expressions, and inhibited JAK2 and Stat3 phosphorylation. Besides, CEP suppressed HCC progression by JAK2/Stat3 pathway. Moreover, CEP inhibited the growth of subcutaneous HCC xenografts and reduced p-JAK2 and p-Stat3 in tumor tissues. CEP could suppress HCC progression by attenuating the JAK2/Stat3 pathway, indicating that CEP might be a therapeutic drug for HCC patients.

Objective: To compare the effects of medical ozone oil and urea ointment for prevention and treatment of hand-foot skin reaction (HFSR) caused by sorafenib in patients with hepatocellular carcinoma (HCC)., Methods: A total of 99 patients diagnosed with advanced HCC according to National Comprehensive Cancer Network (NCCN) who were scheduled to receive sorafenib treatment for the first time were enrolled in this study between April, 2018 and January, 2020. The patients were randomized into medical ozone oil group ( n =49) and urea ointment group (control group, n =49) for treatment with local application of 1 mL medical ozone oil (experimental group) and 10% urea ointment (2 g) on the palm and plantar skin (including the fingers and joints) for 12 weeks (3 times per day) starting at the beginning of sorafenib treatment, respectively. The patients were observed for occurrence of HFSR every 2 weeks for 14 weeks., Results: Eight patients were excluded for poor compliance or protocol violations, leaving a total of 91 patients for analysis, including 44 in medical ozone oil group and 47 in urea ointment group. Sixteen (36.4%) of patients in ozone oil group developed HFSR, a rate significantly lower than that in urea ointment group (57.4%; P < 0.05). The incidence of grade 2/3 HFSR was also lower in ozone oil group than in urea ointment group (15.9% [7/44] vs 27.7 [13/47])., Conclusions: Medical ozone oil can significantly reduce the incidence and severity of HFSR to improve the quality of life of HCC patients receiving sorafenib treatment.

Objective: To explore the effects of hyperpolarization-activated cyclic nucleotide-gated channels 2(HCN2) in the formation of peripheral neuropathic pain in rats., Methods: Twenty-four healthy adult rats were divided into two groups randomly( n =12):the sham group rats were only isolated the left L4, L5 spinal nerve, the spinal nerve ligation(SNL) group was separated the spinal nerve and performed the corresponding ligation. The behavioral experiments were tested 7 days after operation; The model rats were randomly divided into 3 groups( n =6):① negative group(Saline), intra-plantar injection of saline in left hindpaws; ② positive group(gabapentin, GBPT), intraperitoneal injection of gabapentin; ③ experimental group(ZD7288), intra-plantar injection of ZD7288 in left hindpaws. The behavioral experiments were tested before injection and 1 h, 4 h, 24 h and 48 h after injection; Obtaining the dorsal root ganglion(DRG) of the control group (before operation), sham group and the SNL group( n =6), using qPCR and Western blot to analyze the mRNA and protein of HCN2 in rats' DRG., Results: The rat model of neuropathic pain was successfully established. Compared with saline group, GBPT group and ZD7288 group could significantly reduce the symptoms of neuropathic pain in rats after injection 1 h ( P <0.01), and there was no difference between GBPT group and ZD7288 group. Compared with control group and sham group, the expression of HCN2 mRNA in SNL group's DRG was significantly increased ( P <0.01), and the expression of HCN2 channel protein was also increased significantly ( P <0.05)., Conclusions: HCN2 is involved in the development of peripheral neuropathic pain and is likely to be a potential new target for the treatment of neuropathic pain.

Objective: To explore the underlying electrophysiological mechanism of depression induced by chronic pain in dopaminergic neurons in midbrain ventral tegmental area (VTA) of rats., Methods: Twenty-four healthy adult rats were divided into two groups randomly( n =12):12 rats formed the sham group by exposing the spared nerve, and another 12 rats were served as the spared nerve injury (SNI)group by branchedness sciatic nerve injury surgery. The mechanical allodynia test were detected on the day of 3, 7, 14, 28, 42 and 56 after surgery, and the depressive-like behaviors such as open-field test, sucrose preference and forcedswim test were detected at the same time. Then we used the Multichannel Acquisition Processor (MAP) system to record the firing activity of neurons in VTA in both Sham rats and SNI rats., Results: ①Comparing to sham rats, the paw withdrawalmechanical threshold of SNI rats was decreased significantly ( P < 0.01);② According to depression-related behavioral test, SNI rats showed significant difference in open field text, sucrose preference, focus swim text comparing with Sham rats ( P < 0.01);③ The firing rate and burst activity of dopaminergic neuronsin midbrain VTA are increased in depression rats compare to sham rats( P <0.05)., Conclusions: Chronic pain could induce depression, and the increase of spontaneous firing rate of dopaminergic neurons in midbrain VTA might be contribute to the depression induced by the chronic neuropathic pain.

Hyperpolarization-activated and cyclic nucleotide-gated (HCN) channels, distributing in a variety of tissues, especially in excitable cells such as heart cells and many kinds of neurons, have an important role in the modulation of heart rate and neuronal excitability. Different from typical voltage-gated sodium channels and potassium channels, HCN channels were evoked inward currents when the cell was hyperpolarized. More and more recent studies have disclosed that HCN channels play important roles in the nervous system, which were linked with its special electrophysiological features as well as its regulatory effect on the cellular membrane excitability. HCN channels could be modulated by many factors including both extracellular molecules and intracellular signaling cascades, which made its functions complicated in the different condition. Based on its role, HCN channels are presumed to be a promising target for chronic pain and brain disorders. In this paper, we will focus on the advancement of roles of HCN channels in the neural system as well as its complex modulator factors.

Aim: To investigate whether agmatine could selectively block a given type of the voltage-gated calcium channels (VGCC) and whether related receptors are involved in the blocking effect of agmatine on VGCC., Methods: The whole-cell patch recording technique was performed to record VGCC currents in the cultured neonatal rat hippocampal neurons., Results: Verapamil (100 micromol/L), a selective blocker of L-type calcium channel, significantly inhibited VGCC current by 80 %+/- 7 %. Agmatine (100 micromol/L) could further depress the remained currents by 25 %+/-6 %. The alpha 2-adrenoceptor antagonist yohimbine (10 micromol/L) and the I2 imidazoline receptor antagonist idazoxon (10 and 40 micromol/L) had no significant effect on VGCC currents when used respectively. When the mixture of yohimbine and agmatine was applied, VGCC currents were still depressed remarkably. However, the blocking effect of agmatine was decreased by 29 %+/- 8 % in the presence of idazoxon (10 micromol/L). The effect of idazoxon did not increase at a higher concentration (40 micromol/L)., Conclusion: Agmatine could block the L- and other types of VGCC currents in the cultured rat hippocampal neurons. Blocking effect of agmatine on VGCC was partially related to I2 imidazoline receptor and had no relationship with alpha 2-adrenoceptors.

Aim: To investigate the mechanism of agmatine by observing the effect of agmatine on the voltage-gated channels in rat hippocampal neurons., Methods: The whole-cell patch recording technique was performed to record the voltage-gated potassium, sodium, and calcium currents in cultured rat hippocampus. Agmatine was applied directly to the single neuron using a pressure injector with microtubules., Results: Agmatine (500 micromol/L) had no significant effect on the voltage-gated potassium and sodium channels. Agmatine reversibly blocked the voltage-gated calcium channel and the blockade was enhanced with the increasing concentration of agmatine. The inhibitory rates were 21%+/-4%, 35%+/-6%, 49%+/-6%, 67%+/-4%, 69%+/-6%, 86%+/-8%, and 87%+/- 9%, at the concentration of 0.1, 0.5, 1.0, 5.0, 10.0, 50.0, and 100 micromol/L, respectively. IC50 was (1.2+/-0.4) micromol/L. Two-way ANOVA revealed that change of membrane potential displayed a significant interaction with the blockade by agmatine., Conclusion: Agmatine reversibly blocked the voltage-gated calcium channel in rat hippocampal neurons in a concentration- and voltage-dependent way. Agmatine might perform its physiological and pharmacological effects partially by blocking the calcium channel.