Spontaneous Locomotor Activity Research Articles

Specifics of Experimental Modeling 8-OH-DPAT-Induced Perseverative Behavior in Mice.

The effect of 5-HT1A receptor agonist 8-OH-DPAT (intraperitoneal injection in doses of 1, 2, and 4 mg/kg) on spontaneous alternation behavior of mice in Y-maze was studied without and with habituation procedure and food reward. In the first case, 8-OH-DPAT administration led to a decrease in spontaneous alternation and locomotor activity in mice. At the same time, 8-OH-DPAT treatment after habituation and food deprivation increased repeated choices of goal arms without affecting locomotor activity, which was consistent with perseverative behavior. 8-OH-DPAT-induced decrease in spontaneous alternation behavior in Y-maze in mice with habituation and food reward is the most suitable procedure for experimental modeling of the perseverative behavior and studying the anticompulsive activity of new substances.

PRAX-628 is a Novel, Well-Tolerated, Activity Dependent Sodium Channel Blocker with Potent Anticonvulsant Activity (P4-9.012)

<h3>Objective:</h3> We sought to define the <i>in vivo</i> efficacy and tolerability profile of PRAX-628, a novel activity dependent sodium channel blocker. <h3>Background:</h3> Gain-of-function (GoF) pathogenic variants in voltage-gated sodium channel (Na_V) genes can increase persistent sodium current (I_Na) leading to neuronal hyperexcitability and severe developmental and epileptic encephalopathies (DEE). We show in Kahlig et al., (this meeting) that PRAX-628 inhibits I_Na with greater activity dependence compared to standard of care carbamazepine (CBZ) and lamotrigine (LTG). Here we further define its <i>in vivo</i> efficacy and tolerability profile in mice. <h3>Design/Methods:</h3> The anticonvulsant activity of PRAX-628 (0.3–10 mg/kg) was assessed using the maximal electroshock seizure (MES) assay in outbred CD-1 mice. Effects of PRAX-628 (3–20 mg/kg) on spontaneous locomotor activity (sLMA) were measured to assess tolerability. The protective index (PI) of PRAX-628 was determined as the ratio of plasma concentrations in sLMA (TC₅₀) to MES (EC₅₀). The effects of CBZ and LTG were also assessed using MES (3–30 mg/kg and 1–10 mg/kg, respectively) and sLMA (30–96 mg/kg and 20–63.4 mg/kg, respectively), and their corresponding PIs computed. The concentration of PRAX-628 in terminal plasma and brain samples was measured using mass spectrometry. <h3>Results:</h3> PRAX-628 (10 mg/kg) completely blocked evoked seizures (MES ED₅₀ 0.67 mg/kg, brain EC₅₀ 67.2 ng/g) without affecting sLMA (TD₅₀ 10.27 mg/kg, plasma TC₅₀ 1123 ng/g; PI 16.7). In contrast, CBZ and LTG had PIs of 5–6x; full anticonvulsant efficacy with CBZ or LTG was not achieved without reducing sLMA. <h3>Conclusions:</h3> PRAX-628 exhibited markedly improved preclinical tolerability compared to standard of care Na_V blockers, potentially due to its improved activity dependent inhibition of peak I_Na. The profile of PRAX-628 may translate into well-tolerated efficacy in epilepsy as well as other indications caused by neuronal hyperexcitability. <b>Disclosure:</b> Dr. Eckert has received personal compensation for serving as an employee of Praxis Precision Medicines. Dr. Eckert has received personal compensation for serving as an employee of Janssen Research &amp; Development, LLC. Dr. Eckert has received personal compensation for serving as an employee of Inspire Pharmaceuticals, Inc.. Dr. Eckert has stock in Praxis Precision Medicines. Dr. Eckert has stock in Janssen Research and Development. Dr. Eckert has received intellectual property interests from a discovery or technology relating to health care. Dr. Kahlig has received personal compensation for serving as an employee of Praxis Precisoin Medicines. Dr. Kahlig has stock in Praxis Precision Medicines. Dr. Anderson has received personal compensation for serving as an employee of Praxis Precision Medicines. Steven Petrou has received personal compensation in the range of $100,000-$499,999 for serving as a Consultant for Praxis Precision Medicines. Steven Petrou has stock in Praxis Precision Medicines. The institution of Steven Petrou has received research support from Praxis Precision Medicines. The institution of Steven Petrou has received research support from Medical Research Future Fund. Steven Petrou has received intellectual property interests from a discovery or technology relating to health care. Steven Petrou has received intellectual property interests from a discovery or technology relating to health care.

PRAX-562 is a Well-Tolerated, Novel Persistent Sodium Channel Blocker with Broad Anticonvulsant Activity in Multiple DEE Mouse Models (S34.007)

PRAX-562 is a Well-Tolerated, Novel Persistent Sodium Channel Blocker with Broad Anticonvulsant Activity in Multiple DEE Mouse Models (S34.007)

Attenuation of ultraviolet (UV) radiation does not impede host location in egg parasitoids with positive UV phototaxis

Abstract In insects and other terrestrial arthropods, foraging is guided in part by visual cues making use of optical radiation, which includes ultraviolet (UV) radiation. Manipulating UV exposure with lamps and photo‐selective materials can help protect crops by disrupting related wavelength‐dependent behaviours in various pests, but little is known on how this could also affect the behaviour of their natural enemies. To investigate the effects of UV‐A radiation on parasitoid wasp foraging behaviours, we conducted laboratory and semi‐field experiments on female Telenomus podisi and Trissolcus utahensis (Hymenoptera: Scelionidae) that parasitize stink bug egg masses. In small laboratory arenas, both species of egg parasitoid displayed a positive UV phototaxis, but UV exposure also reduced their daily spontaneous locomotor activity regardless of the time of day. In large field cages, parasitism (i.e., host discovery and exploitation) rates were mostly unaffected by UV‐attenuated conditions created by UV‐absorbing filters (macrohabitat level) and/or by the plant canopy (microhabitat level). This study indicates that UV radiation can be involved in egg parasitoid foraging behaviours without UV attenuation negatively affecting parasitism, reflecting the heterogeneity and potentially hazardous nature of this abiotic factor. We highlight the importance of examining the role of UV radiation as an environmental cue in beneficial insects, especially with the prospect of combining physical and biological pest management strategies.

Conditioned catalepsy vs. Increase in locomotor activity induced by haloperidol

Previous research has revealed a high degree of complexity of the conditioned response that appears after associating a context with the effects of the dopaminergic antagonist haloperidol. Specifically, when a drug-free test is performed in the presence of the context, conditioned catalepsy is observed. However, if the test is extended over time, the opposite effect occurs, namely, a conditioned increase in locomotor activity. In this paper, we present the results of an experiment with rats that received repeated administration of haloperidol or saline before or after exposure to the context. Next, a drug-free test was performed to evaluate catalepsy and spontaneous locomotor activity. The results revealed, on the one hand, the expected conditioned response of catalepsy for those animals that received the drug prior to context exposure during conditioning. However, for the same group, an analysis of locomotor activity for an extended period of ten minutes after registering catalepsy revealed an increase in general activity and more faster movements compared to the control groups. These results are interpreted considering the possible temporal dynamics of the conditioned response that could induce changes in dopaminergic transmission responsible for the observed changes in locomotor activity.

TRPV1 inactivation alters core body temperature and serum corticosterone levels: Impacts on clock genes expression in the liver and adrenal glands

PurposeTRPV1 desensitization or blockade promotes hyperthermia in rodents. Daily changes in core body temperature (Tc), spontaneous locomotor activity (SLA), and glucocorticoids are temporal cues for peripheral clocks. Thus, this study aimed to evaluate the effects of both desensitization and blockade of TRPV1 on Tc, SLA, blood corticosterone, and the clock genes Per1 and Bmal1 in the liver and adrenal. Methods and ResultsResiniferatoxin (RTX, 20 μg kg−1) known to desensitize the intra-abdominal TRPV1 channels was i. p. administered in adult male rats. One day after, RTX rats displayed higher Tc than vehicle rats (control) in the light and dark phases. RTX rats showed higher corticosterone at zeitgeber time (ZT) 6 and ZT12 compared to ZT0. Control rats showed a rise in corticosterone at ZT12. RTX abolished the Per1 peak in both the liver and adrenal glands, whereas it enhanced the peak of Bmal1 expression in the liver and decreased it in adrenal glands. Circadian variation in Tc and SLA was unaffected despite higher Tc being found along the light phase up to 5 days after RTX injection. Acute blockade of TRPV1 with the antagonist AMG-517 injected at ZT0 increased Tc and reduced corticosterone without affecting SLA. In the liver, while AMG-517 did not affect Per1, it increased Bmal1 mRNA. In adrenal glands, AMG-517 increased Per1 and did not affect Bmal1 expression. Although rats exposed to a 60-min 34 °C environment showed similar hyperthermia to that observed in AMG-517 rats, neither corticosterone nor liver nor adrenal clock genes changed. ConclusionsInactivation of TRPV1 by abdominal desensitization or by antagonism alters the time-of-day changes of clock genes expression in the liver and adrenal, as well as corticosterone. TRPV1 may be necessary for signaling cyclical temporal cues for clock genes in the periphery but less critical for the circadian profile of Tc and SLA.

Electrical Stimulation of the Auricular Branch Vagus Nerve Using Random and Alternating Frequencies Triggers a Rapid Onset and Pronounced Antihyperalgesia via Peripheral Annexin A1-Formyl Peptide Receptor 2/ALX Pathway in a Mouse Model of Persistent Inflammatory Pain.

This study evaluated the antihyperalgesic and anti-inflammatory effects of percutaneous vagus nerve electrical stimulation (pVNS) by comparing the effects of alternating and random frequencies in an animal model of persistent inflammatory hyperalgesia. The model was induced by Freund's complete adjuvant (CFA) intraplantar (i.pl.) injection. Mice were treated with different protocols of time (10, 20, or 30min), ear laterality (right, left or both), and frequency (alternating or random). Mechanical hyperalgesia was evaluated, and some groups received i.pl. WRW4 (FPR2/ALX antagonist) to determine the involvement. Edema, paw surface temperature, and spontaneous locomotor activity were evaluated. Interleukin-1β, IL-6, IL-10, and IL4 levels were verified by enzyme-linked immunosorbent assay. AnxA1, FPR2/ALX, neutrophil, M1 and M2 phenotype macrophage, and apoptotic cells markers were identified using western blotting. The antihyperalgesic effect pVNS with alternating and random frequency effect is depending on the type of frequency, time, and ear treated. The pVNS random frequency in the left ear for 10min had a longer lasting antihyperalgesic effect, superior to classical stimulation using alternating frequency and the FPR2/ALX receptor was involved in this effect. There was a reduction in the levels of pro-inflammatory cytokines and an increase in the immunocontent of AnxA1 and CD86 in mice paw. pVNS with a random frequency in the left ear for 10min showed to be optimal for inducing an antihyperalgesic effect. Thus, the random frequency was more effective than the alternating frequency. Therefore, pVNS may be an important adjunctive treatment for persistent inflammatory pain.

Abstract TMP113: Kynurenine-3-monooxygenase Inhibition Confers Neuroprotection After Ischemic Stroke In Aged Mice

Background: The kynurenine pathway (KP) is the major route of tryptophan catabolism in mammals. KP branches into two major pathways - one (dependent on the kynurenine aminotransferases) implicated in neuroprotection, the other (dependent on the enzyme kynurenine-3-monooxygenase (KMO) in neurotoxicity. Under physiological conditions, the neuroprotective branch is more active, but under inflammatory conditions, such as seen in stroke, metabolism is shifted through the KP via KMO to produce toxic metabolites, including quinolinic acid. Recent studies have demonstrated that stroke leads to the activation of the KP. Here we tested whether inhibiting KMO activity after stroke could prevent and/or minimize the neuronal death and improve outcomes. Methods: WT C57Bl6 aged male mice were subjected to a 60-minute reversible middle cerebral artery occlusion (MCAO). Tissues collected from a sub-cohort of these mice was used for metabolomics. Other sub-cohort of mice was used for pharmacological studies. For this, mice received either an inhibitor of KMO (Ro 61-8048, 40mg/kg/day i.p) or vehicle immediately after stroke, and infarct was evaluated at day 3 post-stroke. Neurological deficit scores and open field analysis was performed to assess recovery. A separate cohort of aged WT and KMO knockout (KMO-/-) mice was also subjected to MCAO and assessed for infarct and recovery at 3 days after stroke to further evaluate the involvement of KMO on outcome. Results: Stroke caused significant reduction in the aged brain kynurenic acid/quinolinic acid (KYNA/QUIN) ratio, suggesting activation of the neurotoxic/KMO branch of the KP pathway. KMOi treatment administered immediately after the stroke reduced ischemic infarct size (p&lt;.05; n=8 mice/grp) and also improved spontaneous locomotor activity by 72h after stroke compared to vehicle treatment. We also found that genetic deletion of KMO reduces ischemic injury size (p&lt;.05; n=6-7mice/grp) and improves neurological deficit scores. Conclusions: Inhibition or deletion of KMO reduces neuronal death and improves motor function after stroke in aged male mice. Further studies are needed to ascertain if beneficial effects of KMOi on post-stroke recovery is not due to smaller injury, using aged animals of both sexes.

Microbiome and metabolome reveal the metabolic and microbial variations induced by depression and constipation

Depressed patients are often accompaniedwith constipation symptoms, and vice versa. However, the underlying mechanisms of such a bidirectional correlation have remained elusive. We aim to reveal the possible correlations between depression and constipation from the perspectives of gut microbiome and plasma metabolome. We constructed the depressed model and the constipatedmodel of rats, respectively. First, we measured the locomotor activity status and the gastrointestinal functions of rats. And then, nuclear magnetic resonance plasma metabolomics was applied to reveal the shared and the unique metabolites of depression and constipation. In addition, 16 S ribosomal RNA gene sequencing was used to detect the impacts of constipation and depression on gut microbiota of rats. Finally, a multiscale and multifactorial network, that is, the 'phenotypes - differential metabolites - microbial biomarkers' integrated network, was constructed to visualise the mechanisms of connections between depression and constipation. We found that spontaneous locomotor activity and gastrointestinal functions of both depressed rats and constipated rats significantly decreased. Further, eight metabolites and 14 metabolites were associated depression and constipation, respectively. Among them, seven metabolites and four metabolic pathways were shared by constipation and depression, mainly perturbing energy metabolism and amino acid metabolism. Additionally, depression and constipation significantly disordered the functions and the compositions of gut microbiota of rats, and decreased the ratio of Firmicutes to Bacteroidetes. The current findings provide multiscale and multifactorial perspectives for understanding the correlations between depression and constipation, and demonstrate new mechanisms of comorbidity of depression and constipation.

Eplerenone modulates the inflammatory response in monosodium iodoacetate-induced knee osteoarthritis in rats: Involvement of RANKL/OPG axis

AimsOsteoarthritis (OA) is a multifactorial degenerative disease marked by the progressive deterioration of articular cartilage with inflammation of the synovium. OA's main symptoms include pain and function loss. Monosodium Iodoacetate (MIA) experimental model is widely-used for OS induction since it produces symptoms comparable to those occurring in humans. Materials and methodsThirty-two rats were divided into four groups (n = 8). The 1st group received saline and included the normal-control rats. Groups 2–4 received intra-articular injections of MIA (3 mg/50 μL) in the rats' knee joints to induce OA. Group 2 included the MIA-control rats. Groups 3 and 4 received intra-articular MIA followed by a 14-day oral eplerenone (50 and 100 mg/kg); respectively. Key findingsIntra-articular injection of MIA in rats' knee joints caused significant inflammation and pain, elevation of Akt and ERK gene expression in knee joints along with significant alterations in the histological pictures of knee joints and OARSI scores. RANKL/OPG Axis was significantly disrupted. SignificanceEplerenone treatment produced a significant improvement in motor coordination and spontaneous locomotor activity in rats and modulated the key inflammatory mediators in OA (TNF-α, NF-κβ, and IL-6). Eplerenone also suppressed the qRT–PCR gene expression of Akt and ERK in knee joint tissues and improved the histological pictures and OARSI scores of knee joints of treated rats. Eplerenone caused a decline in RANKL concentration accompanied by a rise in OPG concentration thus modulating the RANKL/OPG Axis. Consequently, eplerenone is a candidate for OA therapy due to its potential anti-inflammatory effects.

Electroacupuncture attenuates LPS-induced depression-like behavior through kynurenine pathway.

A growing body of evidence suggests that inflammation and changes in glutamate neurotransmission are two pathophysiological mechanisms underlying depression. Electroacupuncture (EA) is a common therapeutic tool for the treatment of depression. However, the potential antidepressant mechanism of EA remains obscure. The change of the kynurenine pathway (KP) is the research priority of antidepressant mechanisms. This study will investigate the role of EA on lipopolysaccharide (LPS)-induced depression-like behavior and explore its possible mechanism of action. Lipopolysaccharide was used to induce depression-like behavior, and EA was given at Hegu (L14) and Taichong (LR3) acupoints in C57BL/6J mice. Depression-like behaviors were measured by behavioral tests, including tail suspension test (TST), sucrose preference test (SPT), force swim test (FST), and open field test (OFT). The levels of inflammatory cytokines IL-1β, IL-6, and TNF-α, and KP enzyme IDO1 were measured by qPCR and enzyme-linked immunosorbent assay (ELISA), while high-performance liquid chromatography (HPLC) was performed to detect the content of prefrontal cortex and hippocampal as well as serum glutamate, tryptophan (TRP), kynurenic (KYN), and quinolinic acid (QA). The results showed that (1) as evidenced by increased spontaneous locomotor activities, decreased immobility duration, and a stronger preference for sucrose in the sucrose preference test, EA reversed LPS-challenged depressive-like behavior. (2) EA at L14 and LR3 decreased the levels of inflammatory cytokines, inhibited IDO1, and regulated KP metabolisms, as well as lowered the concentration of glutamate. (3) EA may exert anti-depression effects by acting on the kynurenine pathway. This study evaluated the effects of EA on depression-like behaviors induced by lipopolysaccharide (LPS) and its regulation of inflammation and the glutamatergic system. Our results suggest that EA can ameliorate depression-like behaviors, lower the level of inflammation, and reduce the release of glutamate, possibly through the regulation of the kynurenine pathway in the brain.

Antinociceptive efficacy of Clerodendrum petasites S. Moore, a Thai medicinal plant, and its CNS safety profiles.

Clerodendrum petasites, an herbal plant in Thailand, has been used for many years in folk medicine. However, scientific evidence regarding CNS safety pharmacology and antinociceptive activity of C.petasites (CP) has not yet been well characterized. The present study aimed to assess the CNS safety pharmacology and antinociceptive and antiinflammatory effects of CP extract. The effect of CP extract on CNS safety pharmacology was assessed using LABORAS automated home cage monitoring and rotarod test. Its pharmacological activity was evaluated both in-vitro, and in-vivo using hot-plate, acetic acid-induced writhing, formalin, and carrageenan-induced paw edema models. CP extract significantly improved thermal and chemical nociceptive behaviors and acute inflammatory pain at all doses: 300, 600, and 1200mg/kg, p.o. The antiinflammatory effect of CP extract in inflammatory pain models was comparable to the effect of positive control: indomethacin 10mg/kg at all dose levels tested. Further, the CP extract at 600mg/kg dose significantly inhibited 82.3% of carrageenan-induced total edema. In-vitro, CP extract at 12.5, 25, and 50μg/mL concentrations significantly reduced the expression of LPS-induced nitric oxide, IL-6, and TNF-α expression in both RAW 264.7 macrophage and BV-2 microglial cell lines. In addition, CP extract did not show any potential effects on the CNS, indicated by no significant effects on motor coordination, spontaneous locomotor activity, general behaviors, and well-being compared to vehicle-treated mice (p>0.05). Overall, the present study evidences the potential antinociceptive, antiinflammatory efficacies of CP extract with a favorable CNS safety profile.

Brilaroxazine (RP5063), a Novel Serotonin-Dopamine Stabilizer, Displays Antipsychotic Efficacy in Rodents

Introduction: Brilaroxazine (RP5063) displays high affinity for serotonin (5-HT) 1A/2A/2B/7 and dopamine (D) 2/3/4 and moderate affinity for D1, serotonin transporter (SERT), and nicotinic acetylcholine receptor, α4β2. These receptors are associated with multiple psychological disorders. Methods: The pre-clinical assessment involved three standard models emulating human schizophrenia symptoms. The apomorphine climbing test (Protais et al., 1976), in 5 groups of 10 NMRI mice, compared brilaroxazine (1, 3, and 10 mg/kg i.p.), haloperidol (0.5 mg/kg i.p.), and vehicle. The apomorphine-induced deficit in prepulse inhibition (PPI) (Geyer et al., 2001), in 5 groups of 15 Wistar rats, compared brilaroxazine (3, 10, and 30 mg/kg i.p.), haloperidol (1 mg/kg), and vehicle. The dizocilpine effect on locomotion, stereotypy, and rearing (Rung et al. 2005), in 6 groups of 10 Wistar rats, compared brilaroxazine (3, 10, and 30 mg/kg i.p.), olanzapine (6 mg/kg i.p.) and vehicle with (and without) induction. Results: Brilaroxazine decreased apomorphine-induced climbing across the 1, 3, and 10 mg/kg doses versus controls (p&lt;0.001). This compound dose-dependently reversed the apomorphine-induced PPI effects- 10 mg/kg at 87 dB (p&lt;0.05) and 30 mg/kg at all levels (p&lt;0.01). In the dizocilpine-induced model, it decreased versus vehicle controls: (1) spontaneous locomotor activity by 15% (p&lt;0.05, 3 mg/kg), 40% (p&lt;0.001, 10 mg/kg) and 30% (p&lt;0.01, 30 mg/kg); (2) induced locomotion by 25% (p&lt;0.05, 3 mg/kg), 49% (p&lt;0.01, 10 mg/kg), and 47% (p&lt;0.01, 30 mg/kg), (3) stereotypy by 51% and 58% (p&lt;0.001, 10- and 30-mg/kg, respectively), and rearing (only 10 mg/kg, NS). Conclusion: Brilaroxazine showed animal proof-of-concept activity by mitigating pharmacologically induced behaviors in rodents reflecting psychotic symptoms in humans.

Beneficial Effect of Atomoxetine Treatment on Scopolamine-Induced Cognitive Impairments and Molecular Changes in Rats

Objective: Atomoxetine is a noradrenaline re-uptake inhibitory drug that is currently used in the pharmacological treatment of attention deficit/hyperactivity disorder in children, adolescents, and adults. Based on the findings that noradrenergic system is closely associated with learning and memory processes, dysfunction of this system might contribute to the pathophysiology of cognitive disorders. Therefore, atomoxetine, which alters the noradrenergic neurotransmission in the synaptic cleft, has a potential to modulate learning and memory functions in various areas of the central nervous system. In the present study, it was aimed to investigate the effects of atomoxetine treatment on the cognitive impairments in amnesic animals using behavioral and immunohistochemical methods. Method: Male Sprague-Dawley rats (adult, weighing 250-300 g) were used in the experiments. Atomoxetine at doses of 3 or 6 mg/kg (i.p.) was administered to the rats for 14 days. Experimental amnesia was induced in the animals by applying scopolamine (0.5 mg/kg, i.p.) injection. Following the treatment protocol, Morris water maze and passive avoidance tests were conducted to assess spatial and emotional learning and memory parameters of rats, respectively. Piracetam (300 mg/kg daily for 14 days) was used as reference drug in these experiments. In addition, motor performances of the animals were evaluated by activity cage and Rota-rod tests. Subsequent to behavioral tests, rats were euthanized and immunohistochemical analyses were performed to determine the alterations in the BDNF and NGF levels in the hippocampi of the animals. Results: In the Morris water maze test, amnesic rats found the hidden platform slower and spent less time in the target quadrant compared to the healthy controls. On the other hand, atomoxetine treatments significantly decreased the escape latencies, and also increased the target quadrant time values of the amnesic animals at both doses. Data obtained from the passive avoidance test showed that second transition latency values of the amnesic rats were significantly shortened with respect to the control animals; while atomoxetine treatment prolonged these shortened values significantly. It was observed that atomoxetine did not alter motor coordination or spontaneous locomotor activities of animals. Moreover, this drug increased the BDNF and NGF levels in the hippocampal sub-regions which were diminished by scopolamine administration. Conclusions: The obtained findings showed that atomoxetine treatment significantly improved the impaired learning and memory performances of the rats induced by scopolamine administration. Furthermore, anti-amnesic effects of this drug were concomitant with increased neurotrophic factors levels in the hippocampal brain regions. These results suggest a notable therapeutic potential of this drug in the treatment of dementia and several cognitive disorders; however, it should be underlined they are needed to be confirmed by well-designed clinical trials.

Anxiolytic effect of the herbal remedy “Ky cuc dia hoang thang gia vi” in experimental animals

The present study evaluated the anxiolytic effect of the herbal remedy “Ky cuc dia hoang thang gia vi” in experimental animals. Swiss mice were treated with “Ky cuc dia hoang thang gia vi” remedy at 31.2 and 62.4 g/kg per day for seven consecutive days. The anxiolytic effect of “Ky cuc dia hoang thang gia vi” was assessed in mice using elevated plus maze, spontaneous locomotor activity, rotarod performance and grip strength tests. The results showed that “Ky cuc dia hoang thang gia vi” remedy increased the frequency and time in the open arms and decreased the index of open arm avoidance. Moreover, “Ky cuc dia hoang thang gia vi” remedy inhibited spontaneous locomotion, shortened the stay time on the rotating cylinder in rotarod performance test, and reduced the force in the grip strength test. No statistically significant difference in the anxiolytic effect was found between two doses after three hours of the last administration. Our findings demonstrated that “Ky cuc dia hoang thang gia vi” remedy exerted anxiolytic effect. The rationale for the ethnomedicinal use of “Ky cuc dia hoang thang gia vi” remedy for the management of anxiety was confirmed scientifically in this study.

Label-Free Imaging of Humic Substance Bioaccumulation by Pump–Probe Microscopy

Humic substances (HS) are the most abundant forms of natural organic matter on the earth surface. Comprised of decomposed plant and animal materials rich in carbon, oxygen, hydrogen, nitrogen, and sulfur complexes, HS facilitate global carbon and nitrogen cycling and the transport of anthropogenic contaminants. While it is known that HS also interact with organisms at different trophic levels to produce beneficial and harmful effects whether HS exert these biological effects through accumulation remains unknown. Current radiolabeling techniques, which only detect the amount of accumulated radiolabels, cannot visualize the transport and accumulation behavior of HS. Here, using a label-free method based on pump-probe microscopy, we show HS entered the protozoan Tetrahymena thermophila, zebrafish embryos, and human cells and exerted direct effects on these organisms. HS accumulated in the nucleus of T. thermophila, chorion pore canals of zebrafish embryos, and nucleus of intestinal and lung cells in a concentration- and time-dependent way. Epigenetic and transcriptomics assays show HS altered chromatin accessibility and gene transcription in T. thermophila. In zebrafish larvae, HS induced neurotoxicity, altering spontaneous muscle contraction and locomotor activity. Detailed images showing HS accumulation in our study reveal new insights on the ecological and environmental behavior of HS.

Effects of ELF-PEMF exposure on spontaneous alternation, anxiety, motor co-ordination and locomotor activity of adult wistar rats and viability of C6 (Glial) cells in culture

The effects of ELF-PEMF exposure on spontaneous alternation, anxiety, motor coordination, and locomotor activity have been discussed in various pre-clinical and clinical settings. Several epidemiological and experimental studies have demonstrated the potential effects of ELF-PEMF when exposed > ∼1 h/day; however, very few studies have focused on understanding the influence of ELF-PEMF exposure of 1–3 mT with an exposure duration of < 1 h/day on spontaneous alternation, anxiety, motor coordination, and locomotor activity. Hence, we attempted to study the effects of ELF-PEMF exposure of 1–3 mT, 50 Hz with an exposure duration of 20 min each with a 4 h gap (2 times) on the cellular proliferation and morphologies of C6 (Glial) cells and spontaneous alternation, anxiety, motor coordination and locomotor activity of Wistar rats under in vitro and in vivo conditions, respectively. The results showed that ELF-PEMF exposure did not induce any significant levels of cellular fragmentation and changes in the morphology of glial cells. Also, the outcomes revealed no noticeable effects on spontaneous alternation, anxiety, motor coordination, and locomotor activity in PEMF-exposed groups compared with the control. No undesirable side effects were observed at the highest dose (B=3 mT). We also performed histological analysis of the selected brain sections (hippocampus and cortex) following ELF-PEMF exposure. Incidentally, no significant changes were observed in cortical cell counts, tissue structure, and morphology.

Daily, limited access to methamphetamine self-administration during pregnancy leads to increased methamphetamine sensitivity in adult offspring.

Methamphetamine use by women, even throughout pregnancy, is common. But there is limited knowledge about the effects in prenatally methamphetamine-exposed children. This study investigated how prenatal methamphetamine exposure in rats, via maternal i.v. self-administration, affected the sensitivity of adult offspring to methamphetamine in comparison with controls. The offspring were generated from dams either self-administering methamphetamine daily under limited-access conditions prior to and throughout pregnancy, or their respective saline-yoked control dams. Spontaneous and methamphetamine-induced locomotor activity was assessed in male and female offspring of both exposure groups after a range of methamphetamine doses. In a separate group of offspring, acquisition of i.v. methamphetamine self-administration, responding under fixed and progressive ratio schedules of methamphetamine reinforcement, and reinstatement of extinguished drug-seeking behavior were assessed. Methamphetamine dose-dependently increased locomotor activity in both exposure groups. However, methamphetamine-exposed males showed significantly enhanced locomotor activity compared with controls at 1mg/kg, and methamphetamine-exposed females showed significantly enhanced locomotor activity compared with controls at 3.2mg/kg. Methamphetamine-exposed offspring of both sexes acquired methamphetamine self-administration faster and showed overall higher levels of methamphetamine-induced reinstatement compared with controls. Taken together, these results indicate that prenatal methamphetamine exposure to relatively low levels alters methamphetamine sensitivity in male and female adult offspring.

Pupillary dynamics of mice performing a Pavlovian delay conditioning task reflect reward-predictive signals.

Pupils can signify various internal processes and states, such as attention, arousal, and working memory. Changes in pupil size have been associated with learning speed, prediction of future events, and deviations from the prediction in human studies. However, the detailed relationships between pupil size changes and prediction are unclear. We explored pupil size dynamics in mice performing a Pavlovian delay conditioning task. A head-fixed experimental setup combined with deep-learning-based image analysis enabled us to reduce spontaneous locomotor activity and to track the precise dynamics of pupil size of behaving mice. By setting up two experimental groups, one for which mice were able to predict reward in the Pavlovian delay conditioning task and the other for which mice were not, we demonstrated that the pupil size of mice is modulated by reward prediction and consumption, as well as body movements, but not by unpredicted reward delivery. Furthermore, we clarified that pupil size is still modulated by reward prediction even after the disruption of body movements by intraperitoneal injection of haloperidol, a dopamine D2 receptor antagonist. These results suggest that changes in pupil size reflect reward prediction signals. Thus, we provide important evidence to reconsider the neuronal circuit involved in computing reward prediction error. This integrative approach of behavioral analysis, image analysis, pupillometry, and pharmacological manipulation will pave the way for understanding the psychological and neurobiological mechanisms of reward prediction and the prediction errors essential to learning and behavior.

Characterization of a WD-repeat family protein WDR3 in the brain of WDR3 hetero knockout mice

The nuclear protein WDR3 is a member of the WD-repeat family and is a component of the 18S pre-rRNA processing complex. However, the expression and function of WDR3 in the brain remains unknown. To characterize WDR3 in the adult mouse brain, we developed Wdr3 heterozygous knockout (WDR3-HKO) mice. Notably, no homozygous Wdr3 knockout mice were born, suggesting that complete absence of WDR3 causes lethal abnormalities during embryogenesis. Brain Wdr3 mRNA expression was significantly reduced to 60% in the WDR3-HKO mice compared to wild type (WT) mice, while the expression of 18S rRNA did not decline. Using immunohistochemistry and X-gal staining, we demonstrated that WDR3 is widely expressed in the mouse brain, especially in the hippocampus, habenular nucleus, and cerebellum. We observed no differences in body weight during adulthood or developmental weight gain between the WDR3-HKO and WT mice. Interestingly, WDR3-HKO mice exhibited a slight but significant increase in spontaneous locomotor activity compared to WT littermates. In conclusion, the WDR3-HKO mice showed no significant phenotypic changes. Further studies are required to explore the behavioral characteristics of WDR3-HKO mice.