Stimulating GABAergic Neurons in the Nucleus Accumbens Core Alters the Trigeminal Neuropathic Pain Responses in a Rat Model of Infraorbital Nerve Injury

The nucleus accumbens core (NAcc) is an important component of brain reward circuitry, but studies have revealed its involvement in pain circuitry also. However, its effect on trigeminal neuralgia (TN) and the mechanism underlying it are yet to be fully understood. Therefore, this study aimed to examine the outcomes of optogenetic stimulation of NAcc GABAergic neurons in an animal model of TN. Animals were allocated into TN, sham, and control groups. TN was generated by infraorbital nerve constriction and the optogenetic virus was injected into the NAcc. In vivo extracellular recordings were acquired from the ventral posteromedial nucleus of the thalamus. Alterations of behavioral responses during stimulation “ON” and “OFF” conditions were evaluated. In vivo microdialysis was performed in the NAcc of TN and sham animals. During optogenetic stimulation, electrophysiological recordings revealed a reduction of both tonic and burst firing activity in TN animals, and significantly improved behavioral responses were observed as well. Microdialysis coupled with liquid chromatography/tandem mass spectrometry analysis revealed significant alterations in extracellular concentration levels of GABA, glutamate, acetylcholine, dopamine, and citrulline in NAcc upon optic stimulation. In fine, our results suggested that NAcc stimulation could modulate the transmission of trigeminal pain signals in the TN animal model.     

Multicriteria programming in medical diagnosis and treatments

This paper deals with a special case of multicriteria optimization problems. The problems studied come from the medical domain and are of a very important practical relevance. One of the problems refers to the ranking of treatments for the Trigeminal Neuralgia. The second problem refers to a hierarchy of risk factors for Bronchial Asthma. The most common way to deal with a multiobjective optimization problem is to apply Pareto dominance relationship between solutions. But in the cases studied here, a decision cannot be made just by using Pareto dominance. In one of the experiments, all the potential solutions are nondominated (and we need to clearly find a hierarchy of these solutions) and in the second experiment most of the solutions are nondominated between them. We propose a novel multiple criteria procedure and then an evolutionary scheme is applied for solving the problems. Results obtained by the proposed approach in a very simple way are same as the results (or even better) obtained by applying weighted-sum method. The advantage of the proposed technique is that it does not require any additional information about the problem (like weights for each criteria in the case of weighted-sumapproach).     

复杂地质条件下三叉双向旋扩桩低应变检测方法研究

对地质条件较复杂的三个承力盘三叉双向旋扩桩低应变检测方法进行研究,通过对相近并不同的地质条件进行比对,采用PIT桩身完整性测试仪,对不同的方法进行信号的采集,得到最适宜的信号进行分析,并依据《建筑基桩检测技术规范》(JGJ 106-2014),结合多种手段对桩身完整性进行判断。     

The Role of Prostaglandin E1 as a Pain Mediator through Facilitation of Hyperpolarization-Activated Cyclic Nucleotide-Gated Channel 2 via the EP2 Receptor in Trigeminal Ganglion Neurons of Mice

Cyclooxygenase metabolizes dihomo-γ-linolenic acid and arachidonic acid to form prostaglandin (PG) E, including PGE1 and PGE2, respectively. Although PGE2 is well known to play an important role in the development and maintenance of hyperalgesia and allodynia, the role of PGE1 in pain is unknown. We confirm whether PGE1 induced pain using orofacial pain behavioral test in mice and determine the target molecule of PGE1 in TG neurons with whole-cell patch-clamp and immunohistochemistry. Intradermal injection of PGE1 to the whisker pads of mice induced a reduced threshold, enhancing the excitability of HCN channel-expressing trigeminal ganglion (TG) neurons. The HCN channel-generated inward current (I_h) was increased by 135.3 ± 4.8% at 100 nM of PGE1 in small- or medium-sized TG, and the action of PGE1 on I_h showed a concentration-dependent effect, with a median effective dose (ED₅₀) of 29.3 nM. Adenylyl cyclase inhibitor (MDL12330A), 8-bromo-cAMP, and the EP2 receptor antagonist AH6809 inhibited PGE1-induced I_h. Additionally, PGE1-induced mechanical allodynia was blocked by CsCl and AH6809. PGE1 plays a role in mechanical allodynia through HCN2 channel facilitation via the EP2 receptor in nociceptive neurons, suggesting a potential therapeutic target in that PGE1 could be involved in pain as endogenous substances under inflammatory conditions.     

超激光照射并针灸治疗原发性三叉神经痛的疗效观察

目的:观察超激光照射并针灸治疗原发性三叉神经痛的疗效.方法:将42例原发性三叉神经痛患者随机分为两组,治疗组21例,采用超激光照射并针灸治疗:对照组21例,单纯用针灸治疗.结果:治疗组愈显率85.7%,对照组愈显率为66.7%.两组比较差异显著(P＜0.05).结论:超激光照射并针灸治疗原发性三叉神经痛可明显提高疗效,且疗效巩固.     

半导体激光与微波联用药物治疗护理带状疱疹后遗神经痛的疗效观察

探究半导体激光照射与微波联用药物治疗护理带状疱疹后遗神经痛( post-herpetic neuralgia, PHN)的疗效。选择78例带状疱疹后遗神经痛患者,随机分为对照组和观察组,各39例。对照组采取微波联用口服维生素B1、甲钴胺及曲马多,观察组在此基础上采用半导体激光照射治疗。治疗1个疗程后据患者疼痛视觉模拟评分( VAS)对两组疗效进行比较。对照组痊愈4例,显效14例;观察组痊愈12例,显效17例。观察组疗效明显优于对照组( Z=3.391, P=0.001)。半导体激光与微波联用药物能有效护理治疗PHN。     

17β-Estradiol Exacerbated Experimental Occlusal Interference-Induced Chronic Masseter Hyperalgesia by Increasing the Neuronal Excitability and TRPV1 Function of Trigeminal Ganglion in Ovariectomized Rats

Pain symptoms in temporomandibular disorders (TMD) predominantly affect reproductive women, suggesting that estrogen regulates pain perception. However, how estrogen contributes to chronic TMD pain remains largely unclear. In the present study, we performed behavioral tests, electrophysiology, Western blot and immunofluorescence to investigate the role and underlying mechanisms of estrogen in dental experimental occlusal interference (EOI)-induced chronic masseter mechanical hyperalgesia in rats. We found that long-term 17β-estradiol (E2) replacement exacerbated EOI-induced masseter hyperalgesia in a dose-dependent manner in ovariectomized (OVX) rats. Whole-cell patch-clamp recordings demonstrated that E2 (100 nM) treatment enhanced the excitability of isolated trigeminal ganglion (TG) neurons in OVX and OVX EOI rats, and EOI increased the functional expression of transient receptor potential vanilloid-1 (TRPV1). In addition, E2 replacement upregulated the protein expression of TRPV1 in EOI-treated OVX rats. Importantly, intraganglionic administration of the TRPV1 antagonist AMG-9810 strongly attenuated the facilitatory effect of E2 on EOI-induced masseter mechanical sensitivity. These results demonstrate that E2 exacerbated EOI-induced chronic masseter mechanical hyperalgesia by increasing TG neuronal excitability and TRPV1 function. Our study helps to elucidate the E2 actions in chronic myogenic TMD pain and may provide new therapeutic targets for relieving estrogen-sensitive pain.     

Investigating the oronasal contributions to metallic perception

Metallic taints elicited when consuming food can be unpleasant for the consumer and are therefore problematic to food manufacturers. Although metallic has been proposed as a taste in the past, evidence remains inconclusive. This study investigates the oral and nasal contributions to metallic perception using sensory evaluation and headspace analysis using gas chromatography–mass spectrometry (GC‐MS). When sniffing the headspace over divalent salt solutions, some were discriminated from water. GC‐MS did not detect volatiles in the sample headspace, one hypothesis being that sample volatiles react with phospholipids in the nasal cavity and it is lipid oxidation products which are perceived. Copper sulphate was reported as metallic when tasted with the nose occluded to eliminate retronasal perception, suggesting a gustatory or trigeminal mechanism may be involved. This work indicates orthonasal stimulation is involved in metallic perception, and contributes to the ongoing debate over metallic being a taste, trigeminal or flavour response.     

The multisensory perception of hop essential oil: a review

Hops are a key ingredient to add bitterness, aroma and flavour to beer, one of the most consumed beverages worldwide. Essential oils from different hop varieties are characterised by similar classes of chemical compounds and complexity, but their contribution to sensory characteristics in beer differs considerably. Volatiles in hop oil are categorised into several chemical classes. These induce diverse aroma and flavour sensations in beer being described as ‘floral’, ‘fruity’ (e.g. contributed by alcohols, esters, sulphur-containing compounds), ‘spicy’, ‘woody’, ‘herbal’ (sesquiterpenes, oxygenated sesquiterpenoids), and ‘green’ (aldehydes). The perception of hop volatiles depends on their concentrations and combinations, but also on threshold levels in different beer matrices or model systems. Several studies attributed modified taste and mouthfeel sensations to the presence of hop volatiles contributing to a multisensory perception of hop flavour. Linalool is frequently observed to show additive and synergistic-type behaviour and to affect aroma perception if combined with geraniol. Linalool has also been found to be involved in aroma-taste interactions, modifying the perception of bitterness qualities in beer. Particularly oxygenated sesquiterpenoids are suggested to be responsible for an irritating, tingling sensation indicating the activation of trigeminal receptors. The majority of these sensory interactions have been discovered almost by accident and a systematic research approach is required to gain a broad understanding of these complex phenomena. This review provides an overview of factors affecting the perception of hop derived volatiles involved in different sensory characteristics of beer, while illustrating the latest advances and highlighting research gaps from a sensory science perspective. © 2020 The Authors. Journal of the Institute of Brewing published by John Wiley & Sons Ltd on behalf of The Institute of Brewing & Distilling