Nucleus accumbens local field potential power spectrums, phase‑amplitude couplings and coherences following morphine treatment

In the past decade, neural processing has been extensively studied in cognitive neuroscience. However, neural signaling in the nucleus accumbens (NAc) that might clarify reward process remained to be investigated. Male Swiss albino ICR mice implanted with intracranial electrodes into the NAc and the ventral tegmental area (VTA) were used for morphine administration and local field potential (LFP) recording. One‑way ANOVA revealed significant increases in low (30.3–44.9 Hz) and high (60.5–95.7 Hz) gamma powers in the NAc following morphine administration (5 and 15 mg/kg, i.p.). These gamma activities oscillated independently with different time‑course responses. Locomotor activity was also significantly increased by morphine administration. Regression analyses revealed that high gamma activity induced by morphine was positively correlated with distance travelled by animals. Low and high gamma powers were completely abolished by injection of naloxone, a non‑specific opiate antagonist. Analysis of phase‑amplitude coupling confirmed that slow oscillations at 1–4 Hz (delta) and 4–8 Hz (theta) for phase were found to significantly increase modulation index of broad (30.27–80.77 Hz) and narrow (59.48–70.34 Hz) frequency ranges for amplitude, respectively. Moreover, significant increases in coherence values between the NAc and the VTA during 30–40 min following morphine administration were seen for 22.46–44.90 Hz frequency range. Altogether, this study demonstrated changes of LFP oscillations in the NAc with low and high gamma activities, delta‑ and theta‑gamma couplings and interplay with VTA in response to morphine administration. These findings represent neural signaling in the mesolimbic dopamine pathway that might process reward function

Treatment with Pueraria mirifica extract prevented muscle atrophy and restored muscle strength in ovariectomized rats

Pueraria mirifica (PM) is a phytoestrogen-rich plant that was tested to establish if its phytosteroids could prevent estrogen dependent sarcopenia. The effect of PM on the estrogen levels, estrous cycle, toxicity, muscle mass, strength and endurance of extensor digitorum longus (EDL) and gastrocnemius muscles of ovariectomized rats was investigated. Adult female Wistar rats were divided into six groups: Sham-operated (SHAM); ovariectomized (OVX) fed with distilled water (PM0); OVX injected with 40 μg/kg estradiol benzoate (E40); (4-6) OVX fed with ethanolic extract of PM at doses of 50 (PM50), 500 (PM500) and 1000 (PM1000) mg/kg for 90 days. After treatment with all three doses of PM, no toxicity was detected to the hematopoietic system and liver function whereas the E40 group did show toxic effects. Treatment with 50 and 500 mg/kg of PM showed no effect on uterine hypertrophy and caused no arrest of the estrous cycle whereas treatment with estrogen and 1000 mg/kg of PM treatment did. The estrogen level, the cross sectional area of the EDL and the gastrocnemius muscle fiber strength and endurance were all significantly reduced in the PM0 group compared to that of the SHAM group (p<0.05) but were significantly increased in the E40, PM50, PM500 and PM1000 compared to that of the PM0 group (p<0.05). This indicated that the estrogenic activity of PM alleviated muscle atrophy and built up muscle strength and endurance. Thus, the 50 and 500 mg/kg of PM were suitable for treating estrogen dependent sarcopenia in ovariectomized rats

ANet: Autoencoder-Based Local Field Potential Feature Extractor for Evaluating An Antidepressant Effect in Mice after Administering Kratom Leaf Extracts

Kratom (KT) typically exerts antidepressant (AD) effects. However, evaluating which form of KT extracts possesses AD properties similar to the standard AD fluoxetine (flu) remained challenging. Here, we adopted an autoencoder (AE)-based anomaly detector called ANet to measure the similarity of mice's local field potential (LFP) features that responded to KT leave extracts and AD flu. The features that responded to KT syrup had the highest similarity to those that responded to the AD flu at 85.62 $\pm$ 0.29%. This finding presents the higher feasibility of using KT syrup as an alternative substance for depressant therapy than KT alkaloids and KT aqueous, which are the other candidates in this study. Apart from the similarity measurement, we utilized ANet as a multi-task AE and evaluated the performance in discriminating multi-class LFP responses corresponding to the effect of different KT extracts and AD flu simultaneously. Furthermore, we visualized learned latent features among LFP responses qualitatively and quantitatively as t-SNE projection and maximum mean discrepancy distance, respectively. The classification results reported the accuracy and F1-score of 79.78 $\pm$ 0.39% and 79.53 $\pm$ 0.00%. In summary, the outcomes of this research might help therapeutic design devices for an alternative substance profile evaluation, such as Kratom-based form in real-world applications

Jasmine essential oil promotes delta-beta power activities in the dorsal hippocampus under slow wave sleep promotion

Analyzing sleep electroencephalography (EEG) data can provide insights from application of basic principles of signal analysis (filtering, sampling, and spectral processing). This study investigated whether jasmine essential oil (JEO) intake differed in sleep EEG patterns from sedative drug intake. Adult male Swiss Albino (ICR) mice treated with distilled water, jasmine essential oil and lorazepam administration were assessed for sleep stages offline from the dorsal hippocampal brain activity. Two-way repeated measures ANOVA revealed that JEO reduced the wakening duration while increasing NREM sleep following 60 minutes of intake to the end of the 3-hour recording, in comparison to water gavage. Their pharmaco-EEG fingerprints after a single intake of jasmine oil and lorazepam showed a high power-level of delta and beta frequencies in the first 30 minutes of recording. A dramatic decrease in gamma2 power activity was observed only after lorazepam was administered. Slow wave activity within the hippocampus was a highlight of the scent relaxant as promoter of non-REM sleep

Mitragynine Attenuates Withdrawal Syndrome in Morphine-Withdrawn Zebrafish

A major obstacle in treating drug addiction is the severity of opiate withdrawal syndrome, which can lead to unwanted relapse. Mitragynine is the major alkaloid compound found in leaves of Mitragyna speciosa, a plant widely used by opiate addicts to mitigate the harshness of drug withdrawal. A series of experiments was conducted to investigate the effect of mitragynine on anxiety behavior, cortisol level and expression of stress pathway related genes in zebrafish undergoing morphine withdrawal phase. Adult zebrafish were subjected to two weeks chronic morphine exposure at 1.5 mg/L, followed by withdrawal for 24 hours prior to tests. Using the novel tank diving tests, we first showed that morphine-withdrawn zebrafish display anxiety-related swimming behaviors such as decreased exploratory behavior and increased erratic movement. Morphine withdrawal also elevated whole-body cortisol levels, which confirms the phenotypic stress-like behaviors. Exposing morphine-withdrawn fish to mitragynine however attenuates majority of the stress-related swimming behaviors and concomitantly lower whole-body cortisol level. Using real-time PCR gene expression analysis, we also showed that mitragynine reduces the mRNA expression of corticotropin releasing factor receptors and prodynorphin in zebrafish brain during morphine withdrawal phase, revealing for the first time a possible link between mitragynine's ability to attenuate anxiety during opiate withdrawal with the stress-related corticotropin pathway

Exploring of cardiac autonomic activity with heart rate variability in long-term kratom (Mitragyna speciosa Korth.) users: a preliminary study

Background Kratom is a psychoactive plant used to enhance productivity among laborers in Southeast Asian countries. Previous findings from in vitro research of mitragynine, a major component of kratom, suggested a possible risk of heart function abnormality. However, the cardiac autonomic function in long-term kratom users with chewing forms has never been studied. This study aimed to investigate heart rate variability (HRV) indices of cardiac autonomic function in long-term kratom chewers (LKC), compared to the control levels, and also to examine the correlation between HRV indices and relevant kratom use factors. Method A total number of 50 participants consisted of LKC (n = 31) who regularly chewed fresh kratom leaves for at least 2 years and demographically matched control subjects (n = 19). Resting electrocardiogram (ECG) signals were recorded from subjects for 3 min to analyze the ultrashort HRV in the frequency domain. The normalized low frequency (LFn) and high frequency (HFn) were chosen to be the HRV indices to evaluate cardiac autonomic function. The comparison of HRV indices between groups and the correlation between HRV indices and duration and quantity of kratom use was further conducted in statistical analysis. Results The LKC significantly increased LFn together with enhanced HFn compared to the control group tested, indicating that LKC changed cardiac autonomic function with parasympathetic dominance. Furthermore, no significant correlation between the HRV indices and the duration and quantity of kratom use was found, suggesting that the HRV indices were not relevant to these factors. The present study provided scientific-based evidence of cardiac autonomic modulation in long-term kratom chewers. LFn and HFn may be promising cardiac autonomic indicators for monitoring health outcomes in LKC

Anorectic effect, biochemical and hematological profiles of alkaloid extract from Mitragyna speciosa Korth. in rats

There is an on-going debate about medicinal use of kratom plant (Mitragyna speciosa (MS)) on whether it has beneficial or adverse effects. This study aimed to examine long-term weight-reducing effects, toxicity, and dopamine pathway activation of MS alkaloid extract on adult male Wistar rats. In anorexic study, the rats were divided into 3 groups (n = 10), receiving intragastric administration once a day for 19 weeks as control (distilled water), chronic (20 mg/kg MS alkaloid extract) and withdrawal (20 mg/kg MS alkaloid extract for week 1-12 and distilled water for week 13-19) groups. Body weights were measured daily, and blood samples were collected at the end of study for biochemical and hematological tests. In immunohistochemistry, the effects of the extract (40 and 80 mg/kg) on the nucleus accumbens (NAc) and striatum (STr) were determined by using Fos-like immunoreactivity. From week 2 to 19, the results showed a significant reduction in body weight gain produced by the extract. Cessation of the treatment at week 12 did not result in a rebound weight gain. Chronic MS alkaloid extract treatment significantly decreased non-fasting blood sugar, triglyceride, uric acid and blood urea nitrogen (BUN). However, elevated SGOT may suggest possible hepatotoxicity. Chronic MS alkaloid extract treatment also produced baseline levels for most of the hematological parameters except a decrease of monocyte. In immunohistochemistry, the acute treatment did not induce Fos-like immunoreactivity in the NAc and STr. These data demonstrated the beneficial effects of the MS alkaloid extract for possible treatment of metabolic syndromes without toxicity and rewarding effect