Real-time monitoring of cortical brain activity in response to acute pain using wide-area Ca2+ imaging

Previous human and rodent studies indicated that nociceptive stimuli activate many brain regions that is involved in the somatosensory and emotional sensation. Although these studies have identified several important brain regions involved in pain perception, it has been a challenge to observe neural activity directly and simultaneously in these multiple brain regions during pain perception. Using a transgenic mouse expressing G-CaMP7 in majority of astrocytes and a subpopulation of excitatory neurons, we recorded the brain activity in the mouse cerebral cortex during acute pain stimulation. Both of hind paw pinch and intraplantar administration of formalin caused strong transient increase of the fluorescence in several cortical regions, including primary somatosensory, motor and retrosplenial cortex. This increase of the fluorescence intensity was attenuated by the pretreatment with morphine. The present study provides important insight into the cortico-cortical network during pain perception.

Combined treatment with basalt stone and placenta extract to improve the chronic pain and scar after breast cancer surgery: a case report

BACKGROUND

The changes in body image caused by breast deformities and postoperative pain have a detrimental influence on the physical and mental health of patients with breast cancer. The postoperative quality of life (QOL) of these patients reduces significantly owing to the changes in the breast, an organ unique to women, that occur following breast cancer surgery.

CASE PRESENTATION

This case report presents the case of a Asian woman in her early 40 s with postoperative hypertrophic scarring and contraction of the scar following mastectomy; the patient presented with decreased range of motion of the upper arm, hyperpigmentation from radiation burns, changes in breast shape, and chronic pain. The patient received a combination therapy comprising Basalt Stone Treatment and the application of horse placenta extract. As a result of a total of eight sessions conducted once every two weeks, the patient's pain and scar improved. No adverse events were observed after the therapy.

CONCLUSION

Combination therapy with Basalt Stone Treatment and horse placenta extract improved the chronic pain and scar after breast cancer surgery.

Investigating the Influence of Morphine and Cocaine on the Mesolimbic Pathway Using a Novel Microimaging Platform

Dopamine (DA)'s relationship with addiction is complex, and the related pathways in the mesocorticolimbic system are used to deliver DA, regulating both behavioral and perceptual actions. Specifically, the mesolimbic pathway connecting the ventral tegmental area (VTA) and the nucleus accumbens (NAc) is crucial in regulating memory, emotion, motivation, and behavior due to its responsibility to modulate dopamine. To better investigate the relationship between DA and addiction, more advanced mapping methods are necessary to monitor its production and propagation accurately and efficiently. In this study, we incorporate dLight1.2 adeno-associated virus (AAV) into our latest CMOS (complementary metal-oxide semiconductor) imaging platform to investigate the effects of two pharmacological substances, morphine and cocaine, in the NAc using adult mice. By implanting our self-fabricated CMOS imaging device into the deep brain, fluorescence imaging of the NAc using the dLight1.2 AAV allows for the visualization of DA molecules delivered from the VTA in real time. Our results suggest that changes in extracellular DA can be observed with this adapted system, showing potential for new applications and methods for approaching addiction studies. Additionally, we can identify the unique characteristic trend of DA release for both morphine and cocaine, further validating the underlying biochemical mechanisms used to modulate dopaminergic activation.

Reinstating olfactory bulb-derived limbic gamma oscillations alleviates depression-like behavioral deficits in rodents

Although the etiology of major depressive disorder remains poorly understood, reduced gamma oscillations is an emerging biomarker. Olfactory bulbectomy, an established model of depression that reduces limbic gamma oscillations, suffers from non-specific effects of structural damage. Here, we show that transient functional suppression of olfactory bulb neurons or their piriform cortex efferents decreased gamma oscillation power in limbic areas and induced depression-like behaviors in rodents. Enhancing transmission of gamma oscillations from olfactory bulb to limbic structures by closed-loop electrical neuromodulation alleviated these behaviors. By contrast, silencing gamma transmission by anti-phase closed-loop stimulation strengthened depression-like behaviors in naive animals. These induced behaviors were neutralized by ketamine treatment that restored limbic gamma power. Taken together, our results reveal a causal link between limbic gamma oscillations and depression-like behaviors in rodents. Interfering with these endogenous rhythms can affect behaviors in rodent models of depression, suggesting that restoring gamma oscillations may alleviate depressive symptoms.

Multi-Region Microdialysis Imaging Platform Revealed Dorsal Raphe Nucleus Calcium Signaling and Serotonin Dynamics during Nociceptive Pain

In this research, we combined our ultralight micro-imaging device for calcium imaging with microdialysis to simultaneously visualize neural activity in the dorsal raphe nucleus (DRN) and measure serotonin release in the central nucleus of the amygdala (CeA) and the anterior cingulate cortex (ACC). Using this platform, we observed brain activity following nociception induced by formalin injection in the mouse’s hind paw. Our device showed that DRN fluorescence intensity increased after formalin injection, and the increase was highly correlated with the elevation in serotonin release in both the CeA and ACC. The increase in calcium fluorescence intensity occurred during the acute and inflammatory phases, which suggests the biphasic response of nociceptive pain. Furthermore, we found that the increase in fluorescence intensity was positively correlated with mouse licking behavior. Lastly, we compared the laterality of pain stimulation and found that DRN fluorescence activity was higher for contralateral stimulation. Microdialysis showed that CeA serotonin concentration increased only after contralateral stimulation, while ACC serotonin release responded bilaterally. In conclusion, our study not only revealed the inter-regional serotonergic connection among the DRN, the CeA, and the ACC, but also demonstrated that our device is feasible for multi-site implantation in conjunction with a microdialysis system, allowing the simultaneous multi-modal observation of different regions in the brain.

Peripheral neuropathy in the pre-diabetic state of the type 2 diabetes mouse model (TSOD mice) involves TRPV1 expression in dorsal root ganglions

Peripheral neuropathy, which is a complication of diabetes mellitus (DM), is thought to occur in the pre-DM state, being known as impaired glucose tolerance (IGT) neuropathy, although its pathogenesis is unknown. Since it is reversible, an effective treatment at the pre-DM stage could stop the progression of peripheral neuropathy and improve patients’ quality of life and reduce medical costs. We investigated the hypersensitivity to mechanical and thermal stimuli during the pre-DM state in Tsumura Suzuki Obese Diabetes (TSOD) mice, a type 2 DM mouse model. The expression pattern of the Transient Receptor Potential Vanilloid 1 (TRPV1)-positive cells in the dorsal root ganglia (DRG) was examined in TSOD mice, which showed a pre-DM state at 5–12 weeks of age and decreased mechanical and thermal nociceptive thresholds. Additionally, the size of TRPV1-positive cells in TSOD mice increased compared with that in non-diabetic controls (Tsumura Suzuki Non-Obesity; TSNO). Furthermore, the expression of TRPV1 on myelinated nerve fibers (neurofilament heavy-positive cells) had significantly increased. Thus, TSOD mice in the pre-DM state at 5–12 weeks of age could be a useful animal model of IGT neuropathy. We also hypothesized that the development of IGT neuropathy may involve a switch in TRPV1 expression from small, unmyelinated neurons to large, myelinated neurons in the DRG.

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The mechanism of peripheral neuropathy was investigated in insulin resistance state.

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Tsumura Suzuki Obese Diabetes (TSOD) mice showed a pre-diabetic state.

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TSOD mice showed mechanical and thermal hypersensitivity in a pre-diabetic state.

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The TRPV1 expression shifted to larger dorsal root ganglia (DRG) cells in TSOD mice.

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TRPV1 expression in myelinated neurons of the DRG was involved in neuropathy.

Application of Kampo medicines for the palliation of cancer cachexia

Cancer cachexia results in the discontinuation of aggressive cancer therapy, and halting its progression has a significant effect on the survival rate and quality of life of patients with cancer. Currently, there are few therapies to control or slow down the progression of cancer cachexia. Although traditional Japanese Kampo medicine is widely used to support aggressive cancer therapy, the relevant scientific evidence is limited. Additionally, Kampo medicines are based on historical experience. In recent years, there have been widespread attempts to prove the efficacy of Kampo medicines through basic research, and an increasing number of studies have clarified the mechanism of action of Kampo medicines at the molecular level. It has been proposed that the improvement of cancer cachexia by Kampo medicines might involve enhancement of feeding via the central nervous system, improvement of protein maintenance in the skeletal muscle, and suppression of inflammatory cytokine production. In particular, among Kampo medicines, tonifying formulae, called "hozai" in Japanese, have been shown to be effective in alleviating cancer cachexia. In this review, we summarize the recent progress of basic and clinical research in Kampo medicines on cancer cachexia, and introduce Kampo medicines that are expected to be attractive supportive cancer medication.

The Medial Septum as a Potential Target for Treating Brain Disorders Associated With Oscillopathies

The medial septum (MS), as part of the basal forebrain, supports many physiological functions, from sensorimotor integration to cognition. With often reciprocal connections with a broad set of peers at all major divisions of the brain, the MS orchestrates oscillatory neuronal activities throughout the brain. These oscillations are critical in generating sensory and emotional salience, locomotion, maintaining mood, supporting innate anxiety, and governing learning and memory. Accumulating evidence points out that the physiological oscillations under septal influence are frequently disrupted or altered in pathological conditions. Therefore, the MS may be a potential target for treating neurological and psychiatric disorders with abnormal oscillations (oscillopathies) to restore healthy patterns or erase undesired ones. Recent studies have revealed that the patterned stimulation of the MS alleviates symptoms of epilepsy. We discuss here that stimulus timing is a critical determinant of treatment efficacy on multiple time scales. On-demand stimulation may dramatically reduce side effects by not interfering with normal physiological functions. A precise pattern-matched stimulation through adaptive timing governed by the ongoing oscillations is essential to effectively terminate pathological oscillations. The time-targeted strategy for the MS stimulation may provide an effective way of treating multiple disorders including Alzheimer's disease, anxiety/fear, schizophrenia, and depression, as well as pain.

Trend in the prevalence of atrial fibrillation 7 years after the Great East Japan Earthquake

Background

The age-adjusted prevalence rate of atrial fibrillation (AF) had kept increasing until 2-year after the Great East Japan Earthquake (reported in ESC2017). Whether the elevated prevalence was tentative or not has not been sufficiently elucidated yet.

Methods

Community dwellers aged 40 to 74 years living in Iwate Prefecture who underwent annual health checkups (2010 (n=17490), 2011 (n=174236), 2012 (n=183612), 2013 (n=188429), 2014 (n=188424), 2015 (n=193610), 2016 (n=194882), 2017 (n=195428) account for approximately 30% of total population) were enrolled. Participants were divided into two age categories (40–64, 65–74 years). Direct age-adjusted prevalence rate of AF in each year was estimated using the 2010 population as the reference.

Result

Data are shown in the figure.

Conclusion

Prevalence rates of AF increased only in elderly people for up to 3 years after the disaster. This indicated that accelerated development of AF in elderly people due to stressful life after the disaster would not end within a short term and lasted at least 3 years after the disaster.

Figure 1

Funding Acknowledgement

Type of funding source: None

Neoline, an active ingredient of the processed aconite root in Goshajinkigan formulation, targets Nav1.7 to ameliorate mechanical hyperalgesia in diabetic mice

ETHNOPHARMACOLOGICAL RELEVANCE

Goshajinkigan (GJG), a traditional Japanese Kampo formula, has been shown to exhibit several pharmacological actions, including antinociceptive effects. Processed aconite root (PA), which is considered to be an active ingredient of GJG, has also been demonstrated to have an ameliorative effect on pain, such as diabetic peripheral neuropathic pain. We recently identified neoline as the active ingredient of both GJG and PA that is responsible for its effects against oxaliplatin-induced neuropathic pain in mice.

AIM OF THE STUDY

In the present study, we investigated whether GJG, PA, and neoline could inhibit Nav1.7 voltage-gated sodium channel (VGSC) current and whether neoline could ameliorate mechanical hyperalgesia in diabetic mice.

MATERIALS AND METHODS

To assess the electrophysiological properties of GJG extract formulation, powdered PA, and neoline on Nav1.7 VGSCs, whole-cell patch clamp recording was performed using human HEK293 cells expressing Nav1.7 VGSCs. In addition, the ameliorative effects of neoline on diabetic peripheral neuropathic pain were evaluated using the von Frey test in streptozotocin (STZ)-induced diabetic model mice.

RESULTS

GJG extract formulation significantly inhibited Nav1.7 VGSC peak current. Powdered PA also inhibited Nav1.7 VGSC peak current. Like GJG and PA, neoline could inhibit Nav1.7 VGSC current. When diabetic mice were treated with neoline by intraperitoneal acute administration, the mechanical threshold was increased in diabetic mice, but not in non-diabetic mice, in a behavioral study.

CONCLUSION

These results suggest that neoline might be a novel active ingredient of GJG and PA that is one of responsible ingredients for ameliorating mechanical hyperalgesia in diabetes via the inhibition of Nav1.7 VGSC current at least.

Visualization of Brain Activity in a Neuropathic Pain Model Using Quantitative Activity-Dependent Manganese Magnetic Resonance Imaging

Human brain imaging studies have revealed several regions that are activated in patients with chronic pain. In rodent brains, functional changes due to chronic pain have not been fully elucidated, as brain imaging techniques such as functional magnetic resonance imaging and positron emission tomography (PET) require the use of anesthesia to suppress movement. Consequently, conclusions derived from existing imaging studies in rodents may not accurately reflect brain activity under awake conditions. In this study, we used quantitative activation-induced manganese-enhanced magnetic resonance imaging to directly capture the previous brain activity of awake mice. We also observed and quantified the brain activity of the spared nerve injury (SNI) neuropathic pain model during awake conditions. SNI-operated mice exhibited a robust decrease of mechanical nociceptive threshold 14 days after nerve injury. Imaging on SNI-operated mice revealed increased neural activity in the limbic system and secondary somatosensory, sensory-motor, piriform, and insular cortex. We present the first study demonstrating a direct measurement of awake neural activity in a neuropathic pain mouse model.

Involvement of l-lactate in hippocampal dysfunction of type I diabetes

Hippocampal neurons play a crucial role in memory formation. Accumulating evidence raises the possibility that hippocampal sharp-wave ripples (SW-Rs) are involved in memory consolidation. Here, we examined in an animal model of diabetes and found the amplitude of SW-Rs in diabetic mice were smaller than control group and were rescued by acute application of l-lactate, a major neural energy source. The cognitive impairment in diabetic mice was alleviated by intracerebroventricular l-lactate treatment. Our results suggested that l-lactate is important for hippocampal dysfunction in diabetes.

P3772Risk factors for future development of atrial fibrillation are not evident among apparently healthy individuals with paroxysmal atrial fibrillation

Background

Atrial fibrillation (AF) is one of the important factors of cardiovascular morbidity and mortality and to find not only patients with persistent AF but also individuals with paroxysmal AF among apparently healthy people is a crucial strategy for decreasing number of patients with serious cardio-embolic stroke. However, screening ability using previously known risk factors for future development of AF has not been examined in individuals with paroxysmal AF.

Methods

A total of 59730 male individuals, aged 40 years or older who underwent multiple comprehensive physical check-ups including 12 lead electrocardiogram (ECG) from 2012 to 2015 were enrolled. Persistent AF was defined a case that consecutively manifested AF till the last checkup. Paroxysmal AF was defined as a case who transiently manifested AF in each of the checkup and subsequently manifested sinus rhythm at the last checkup. Non-AF was defined as a case that never manifested AF in any of checkup. Age-adjusted prevalence rates and their 95% confidence intervals of known-risk factors in the first survey were estimated by logistic regression analysis separately by the three groups (non-AF (n=58602), paroxysmal AF (n=392) and persistent AF (736)).

Results

Age-adjusted prevalence rates (95% confidence interval) of risks factors for AF are shown in the table. Already known risk factors were evidently manifested in persistent AF group, however, prevalence rates of these factors in paroxysmal AF group were not different from the rates in non-AF group.

Conclusion

The repeated measurements of ECG study indicated that individuals who would develop paroxysmal AF in the near future did not have typical risk factors for AF and a screening test using risk factors for AF have no chance to find a high-risk individual for paroxysmal AF.

Neoline is the active ingredient of processed aconite root against murine peripheral neuropathic pain model, and its pharmacokinetics in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Processed aconite root (PA), the root of Aconitum carmichaeli (Ranunculaceae), is a crude drug used in traditional Chinese or Japanese kampo medicine to treat pain associated with coldness. In our previous study, PA and its active ingredient, neoline, alleviated oxaliplatin-induced peripheral neuropathy in mice.

AIM OF THE STUDY

The present study investigated the effects of PA on a murine peripheral neuropathy model induced by intraperitoneal injection of paclitaxel and partial ligation of the sciatic nerve (Seltzer model), and identified its active ingredients.

MATERIALS AND METHODS

PA powder (1 g/kg/day) was orally administered, and either neoline or benzoylmesaconine (10 mg/kg/day) was subcutaneously injected into the murine model. Mechanical hyperalgesia was evaluated via the von Frey filament method. PA extract was orally administered to rats; blood samples were chronologically collected, and the plasma concentrations of Aconitum alkaloids were measured. The contents of Aconitum alkaloids in commercial PA products were also measured.

RESULTS

PA extract and neoline significantly attenuated the mechanical hyperalgesia induced by either paclitaxel or partial ligation of the sciatic nerve in mice. In the plasma samples of rats treated with PA extract, higher concentrations of benzoylmesaconine and neoline were apparent among Aconitum alkaloids. The contents of benzoylmesaconine and neoline varied among PA products with different processing procedures. Subcutaneous injection of benzoylmesaconine did not attenuate the hyperalgesia induced by each paclitaxel, partial ligation of the sciatic nerve, or oxaliplatin in mice.

CONCLUSIONS

The present results indicate that PA and its active ingredient, neoline, are promising agents for the alleviation of neuropathic pain. Neoline can be used as a marker compound to determine the quality of the PA products for the treatment of neuropathic pain.

Chronic brain blood-flow imaging device for a behavioral experiment using mice

A chronic brain blood-flow imaging device was developed for cerebrovascular disease treatment. This device comprises a small complementary metal-oxide semiconductor image sensor and a chronic fiber-optic plate window on a mouse head. A long-term cerebral blood-flow imaging technique was established in a freely moving mouse. Brain surface images were visible for one month using the chronic FOP window. This device obtained brain surface images and blood-flow velocity. The blood-flow changes were measured in behavioral experiments using this device. The chronic brain blood-flow imaging device may contribute to determining the cause of cerebrovascular disease and the development of cerebrovascular disease treatment.

Effect of Ninjin'yoeito on the Loss of Skeletal Muscle Function in Cancer-Bearing Mice

Ninjin'yoeito (NYT), a traditional Japanese Kampo medicine formula, is used as a remedy for conditions, and physical weakness. Cancer cachexia is seen in advanced cancer patients and is defined by an ongoing loss of skeletal-muscle mass that leads to progressive functional impairment. In the present study, we examined the hypothesis whether NYT improves the functional loss of skeletal muscle cancer cachexia. Male C57/BL 6J mice with B16BF6 melanoma tumor showed decreased expression of myosin heavy chain (MHC) in the gastrocnemius muscle. Moreover, the expression of SOCS3 and phosphorylated STAT3 and AMPK was increased, and the expression of phosphorylated 4E-BP1 was decreased in the gastrocnemius muscle of tumor-bearing mice. These data suggested that amino acid metabolism was altered in tumor-bearing mice, which were normalized by the NYT intervention. The present study showed that NYT might be a novel therapeutic option for the treatment of sarcopenia occurring cancer cachexia.

Improvement of Diabetes Mellitus Symptoms by Intake of Ninjin'yoeito

Diabetes mellitus is a well-known common disease and one of the most serious social problems in the worldwide. Although various types of drugs are developed, the number of patients suffering from diabetes mellitus is still increasing. Ninjin'yoeito (NYT) is one of formulas used in Japanese traditional herbal medicines for improving various types of metabolic disorders. However, the effect of NYT on diabetes mellitus has not yet been investigated. In the present study, we tried to clarify the action of NYT on the serum glucose level in streptozotocin (STZ)-induced diabetic mice. We found that intake of NYT decreased the serum glucose level and increased insulin sensitivity in STZ-induced diabetic mice. NYT treatment also improved acidification of the interstitial fluid around skeletal muscles found in STZ-induced diabetic mice, while the interstitial fluid acidification has been reported to cause insulin resistance. Furthermore, in the proximal colon of STZ-induced diabetic mice, NYT treatment showed a tendency to increase the expression of sodium-coupled monocarboxylate transporter 1 (SMCT1), which has ability to absorb weak organic acids (pH buffer molecules) resulting in improvement of the interstitial fluid acidification. Based on these observations, the present study suggests that NYT is a useful formula to improve hyperglycemia and insulin resistance via elevation of interstitial fluid pH in diabetes mellitus, which might be caused by increased absorption of pH buffer molecules (SMCT1 substrates, weak organic acids) mediated through possibly elevated SMCT1 expression in the proximal colon.

Ethanol-induced enhancement of inhibitory synaptic transmission in the rat spinal substantia gelatinosa

Recent studies have shown that ethanol produces a widespread modulation of neuronal activity in the central nervous system. It is not fully understood, however, how ethanol changes nociceptive transmission. We investigated acute effects of ethanol on synaptic transmission in the substantia gelatinosa (lamina II of the spinal dorsal horn) and mechanical responses in the spinal dorsal horn. In substantia gelatinosa neurons, bath application of ethanol at low concentration (10 mM) did not change the frequency and amplitude of spontaneous inhibitory postsynaptic currents. At medium to high concentrations (20–100 mM), however, ethanol elicited a barrage of large amplitude spontaneous inhibitory postsynaptic currents. In the presence of tetrodotoxin, such enhancement of spontaneous inhibitory postsynaptic currents was not detected. In addition, ethanol (20–100 mM) increased the frequency of spontaneous discharge of vesicular GABA transporter-Venus-labeled neurons and suppressed the mechanical nociceptive response in wide-dynamic range neurons in the spinal dorsal horn. The present results suggest that ethanol may reduce nociceptive information transfer in the spinal dorsal horn by enhancement of inhibitory GABAergic and glycinergic synaptic transmission.