Ultrasonic vocalization (USVs) is a promising tool to measure behavioral anxiety in rodents as USV recording is noninvasive, behaviorally relevant, ethological, and reproducible. Studies reporting ...the effects of stress-induced USVs in adult mice remain limited and debated. We investigated the conditions under which mice emit aversive USVs and evaluated the effects of psychiatric drugs on stress-induced USVs. Male C57BL/6J mice were used. USVs during entire stress sessions were recorded according to their frequency. To investigate the effect of psychiatric drugs on USVs, the number of USVs under cold-restraint stress conditions before and after drug administration was compared. Immediately after stress exposure, blood samples were collected and plasma corticosterone levels were measured. The combination of cold and restraint stress conditions significantly increased the USV numbers and plasma corticosterone levels compared with each stress alone. A benzodiazepine anxiolytic (midazolam) and δ-opioid receptor agonist putative anxiolytic (KNT-127) significantly reduced the stress-induced USV number and plasma corticosterone levels; however, a monoaminergic antidepressant (duloxetine) and N-methyl-D-aspartic acid receptor antagonist antidepressant (ketamine) did not reduce the USV numbers. No changes were noted in the USV numbers after repeated exposure to cold-restraint stress on days 1 and 3. The suppressive effect of midazolam on day 3 was comparable to that on day 1. Stress-induced USV may be used as a quantitative measure of anxiety to systematically assess the effects of anxiolytics. Therefore, cold-restraint stress-induced USVs may be used as a novel tool to measure rodent anxiety and as a useful anxiolytic-screening system.
Increasing evidence has demonstrated that emotional states and intestinal conditions are inter-connected in so-called “brain–gut interactions.” Indeed, many psychiatric disorders are accompanied by ...gastrointestinal symptoms, such as the irritable bowel syndrome (IBS). However, the functional connection remains elusive, partly because there are few useful experimental animal models. Here, we focused on a highly validated animal model of stress-induced psychiatric disorders, such as depression, known as the chronic vicarious social defeat stress (cVSDS) model mice, which we prepared using exposure to repeated psychological stress, thereafter examining their intestinal conditions. In the charcoal meal test and the capsaicin-induced hyperalgesia test, cVSDS model mice showed a significantly higher intestinal transit ratio and increased visceral pain-related behaviors, respectively. These changes persisted over one month after the stress session. On the other hand, the pathological evaluations of the histological and inflammatory scores of naive and cVSDS model mice did not differ. Furthermore, keishikashakuyakuto—a kampo medicine clinically used for the treatment of IBS—normalized the intestinal motility change in cVSDS model mice. Our results indicate that cVSDS model mice present IBS-like symptoms such as chronic intestinal peristaltic changes and abdominal hyperalgesia without organic lesion. We therefore propose the cVSDS paradigm as a novel animal model of IBS with wide validity, elucidating the correlation between depressive states and intestinal abnormalities.
Ultrasonic vocalization (USVs) is a promising tool to measure behavioral anxiety in rodents as USV recording is noninvasive, behaviorally relevant, ethological, and reproducible. Studies reporting ...the effects of stress-induced USVs in adult mice remain limited and debated. We investigated the conditions under which mice emit aversive USVs and evaluated the effects of psychiatric drugs on stress-induced USVs. Male C57BL/6J mice were used. USVs during entire stress sessions were recorded according to their frequency. To investigate the effect of psychiatric drugs on USVs, the number of USVs under cold-restraint stress conditions before and after drug administration was compared. Immediately after stress exposure, blood samples were collected and plasma corticosterone levels were measured. The combination of cold and restraint stress conditions significantly increased the USV numbers and plasma corticosterone levels compared with each stress alone. A benzodiazepine anxiolytic (midazolam) and δ-opioid receptor agonist putative anxiolytic (KNT-127) significantly reduced the stress-induced USV number and plasma corticosterone levels; however, a monoaminergic antidepressant (duloxetine) and N-methyl-D-aspartic acid receptor antagonist antidepressant (ketamine) did not reduce the USV numbers. No changes were noted in the USV numbers after repeated exposure to cold-restraint stress on days 1 and 3. The suppressive effect of midazolam on day 3 was comparable to that on day 1. Stress-induced USV may be used as a quantitative measure of anxiety to systematically assess the effects of anxiolytics. Therefore, cold-restraint stress–induced USVs may be used as a novel tool to measure rodent anxiety and as a useful anxiolytic-screening system.
Recently, ultrasound exposure has been shown to be a noninvasive method for modulating brain activity and has to be applied to treat mental disorders, such as depression. However, its underlying ...mechanism remains unclear. Therefore, there is a need for animal models that can investigate the mechanism of ultrasound exposure. In this study, we utilized olfactory bulbectomized (OB) rats as an animal model of depression and investigated their emotional state following ultrasound exposure. As a result, following exposure to high-frequency ultrasonic vocalizations (USV)s of rats, the hyperemotionality of OB rats was significantly suppressed. Also, USV exposure significantly reduced the latency to the first entry into the open arm in the elevated plus maze tests and the plasma corticosterone levels of OB rats. Furthermore, artificial ultrasounds (50 and 100 kHz) also significantly decreased the hyperemotionality score of OB rats. These results suggested that ultrasound exposure, regardless of vocal or artificial sound, ameliorated depressive-like behavior and stress level in OB rats. We proposed that OB rats might be an appropriate animal model to identify mechanisms underlying the effects of ultrasound exposure.
Visible light communication using light is a kind of radio communication. VLC is expected to be used as a communication method for remote control for autonomous mobile robots. In this case, the VLC ...may be used indoors. In one type of VLC, a photodiode receives a signal, a comparator converts the signal into a square wave, and demodulates information from the square wave. There is a possibility that the signal cannot be correctly converted to High /Low if noise, which is light other than the signal, is placed on the signal. Because the noise caused by indoor lighting is periodic, we propose a method to reduce the effect of the periodic noise on the signal using the data of the periodic noise in without signal. The performance of the proposed method is confirmed by comparing the Bit Error Rate with the conventional method without noise countermeasure.
In this study, we investigated the growth response of chondrocytes on a metallic cell culture device with different microtopographies. Two different topographies were generated on 316L stainless ...steel by fine particle peening (FPP) treatment using either glass or alumina shot particles. Glass particles provided surface of micro asperities at low frequency spacing, whereas alumina provided surface micro asperities at high frequency spacing. Calf chondrocytes were seeded and cultured on both treated and smooth stainless steel surfaces. The cells were then counted. Based on the results, the FPP-treated surfaces showed better cell proliferation and denser filopodia compared to the polished surface, indicating that the micro asperities on the surface of the plate encouraged cell proliferation and adhesion. The number of cells observed on the FPP-treated surface depended on the shape of the asperities formed by FPP treatment, and alumina-treated surface had the highest cell counts. Cell distribution assay indicated that cells growing on the alumina-treated surface migrated easily. In addition, when the alumina-treated surface was used as a cell culture dish to incubate chondrocytes, cell proliferation was similar to that of obtained using polymeric culture dishes, demonstrating that FPP-treated surfaces are appropriate for use in cell culture dishes.
Visible light communication (VLC) using the electromagnetic wave in visible light band is a kind of wireless communication technology. In general, the transmission and reception elements of VLC are ...controlled by a microcomputer in a VLC module which makes high and low voltages at time slots correspond by the binary data. A timer interruption controls the timing of sending and reading the slots in the transmitter and the receiver, respectively. A timer interruption is an operation for performing thread processing by pausing the main function. By the specification of the timer interrupt, it becomes difficult to output the slot accurately as the communication speed increases. And it becomes difficult to accurately read. Here, we focus on the function of serial communication. serial communication can support time slots control as an embedded function. We propose the novel control method for VLC elements using the pulse waveform of serial communication where the sending and reading timings are controlled by the embedded serial function. This method makes VLC easy and can control the time slots more severely. We compare the symbol error rate for each communication speed. And we show that the proposed method is more accurate than the conventional method.
Recently, we developed that the mice chronic vicarious social defeat stress (cVSDS) model, known as validated animal model of depression, showed the irritable bowel syndrome (IBS)-like symptoms such ...as chronic intestinal motility changes and abdominal hyperalgesia without organic lesions. Previously, we reported that a selective delta opioid receptor (DOP) agonist KNT-127 improved the depression-like behaviors observed in mice cVSDS model. In the present study, we examined the effects of KNT-127 on the IBS-like symptoms in cVSDS model. The model mice were prepared by exposure to repeated psychological stress for 10 days in C57BL/6J mice. KNT-127 was administered subcutaneously (s.c.) and microinjected into the Insular cortex (IC) 30min before the test, respectively. KNT-127 (10mg/kg, s.c.) significantly improved increased intestinal transit ratio in the charcoal meal test and hypersensitivity symptoms in the capsaicin-induced hyperalgesia test, respectively. In addition, KNT-127 (300ng/mouse) in IC was normalized their intestinal transit ratio. These results suggested that KNT-127 improved the IBS-like symptoms in cVSDS mice via DOPs in IC. We proposed that DOP agonist have the potential to be an effective treatment for IBS, capable of breaking the vicious cycle in gut-brain interactions.
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