Changes In Locomotor Activity Research Articles

Restricted cafeteria feeding and treadmill exercise improved body composition, metabolic profile and exploratory behavior in obese male rats

The aim of this study was to evaluate, in male Long-Evans rats, whether a restricted-cafeteria diet (CAFR), based on a 30% calorie restriction vs continuous ad libitum cafeteria (CAF) fed animals, administered alone or in combination with moderate treadmill exercise (12 m/min, 35 min, 5 days/week for 8 weeks), was able to ameliorate obesity and the associated risk factors induced by CAF feeding for 18 weeks and to examine the changes in circadian locomotor activity, hypothalamic–pituitary–adrenal (HPA) axis functionality, and stress response elicited by this dietary pattern. In addition to the expected increase in body weight and adiposity, and the development of metabolic dysregulations compatible with Metabolic Syndrome, CAF intake resulted in a sedentary profile assessed by the home-cage activity test, reduced baseline HPA axis activity through decreased corticosterone levels, and boosted exploratory behavior. Both CAFR alone and in combination with exercise reduced abdominal adiposity and hypercholesterolemia compared to CAF. Exercise increased baseline locomotor activity in the home-cage in all dietary groups, boosted exploratory behavior in STD and CAF, partially decreased anxiety-like behavior in CAF and CAFR, but did not affect HPA axis-related parameters.

Alpha-pyrrolidinopentiothiophenone (α-PVT) activates the TLR–NF-κB–MAPK signaling pathway and proinflammatory cytokine production and induces behavioral sensitization in mice

Synthetic cathinones are chemical derivatives of cathinone, a structural analog to amphetamine. It has been shown that synthetic cathinones have abuse potentials similar to psychomotor stimulants such as amphetamine and induce neuroinflammation. Among the novel synthetic cathinones, α-pyrrolidinopentiothiophenone (α-PVT) has been known to produce rewarding and reinforcing effects in rodent models. However, it has not yet been determined whether α-PVT induces neuroinflammation in vivo. In the present study, mice were exposed to repeated saline or α-PVT (20 mg/kg, intraperitoneally) for 7 days to test changes in locomotor activity and neuroinflammation-related factors in the striatum of mice. Repeated administration of α-PVT significantly induced locomotor sensitization. In addition, repeated α-PVT administration significantly increased the number of microglial cells, accompanied by marked increases in TLR1, TLR4, TLR6, and TLR7 mRNA levels in the striatum of mice. Furthermore, acute or repeated α-PVT administration increased the levels of phosphorylated NF-κB, ERK, p38, and JNK MAPK activation and repeated α-PVT, but not acute, increased the levels of TNF-α and IL-6 mRNA in the striatum of mice. Finally, systemic administration of TAK-242 (5 mg/kg, i.p.) or MPLA (50 μg/kg, i.p.), each an inhibitor or activator of TLR4, did not change α-PVT-induced behavioral sensitization in mice. These results suggest that the activation of TLR4 by repeated α-PVT administration may lead to neuroinflammation via TLR-mediated NF-κB and MAPK signaling pathways and the production of TNF-α and IL-6 in the striatum of mice, at least without the regulation of behavioral sensitization.

C-type natriuretic peptide preserves central neurological function by maintaining blood-brain barrier integrity.

C-type natriuretic peptide (CNP) is highly expressed in the central nervous system (CNS) and key to neuronal development; however, a broader role for CNP in the CNS remains unclear. To address this deficit, we investigated behavioral, sensory and motor abnormalities and blood-brain barrier (BBB) integrity in a unique mouse model with inducible, global deletion of CNP (gbCNP–/–). gbCNP–/– mice and wild-type littermates at 12 (young adult) and 65 (aged) weeks of age were investigated for changes in gait and motor coordination (CatWalk™ and rotarod tests), anxiety-like behavior (open field and elevated zero maze tests), and motor and sensory function (modified neurological severity score [mNSS] and primary SHIRPA screen). Vascular permeability was assessed in vivo (Miles assay) with complementary in vitro studies conducted in primary murine brain endothelial cells. Young adult gbCNP–/– mice had normal gait but reduced motor coordination, increased locomotor activity in the open field and elevated zero maze, and had a higher mNSS score. Aged gbCNP–/– animals developed recurrent spontaneous seizures and had impaired gait and wide-ranging motor and sensory dysfunction. Young adult and aged gbCNP–/– mice exhibited increased BBB permeability, which was partially restored in vitro by CNP administration. Cultured brain endothelial cells from gbCNP–/– mice had an abnormal ZO-1 protein distribution. These data suggest that lack of CNP in the CNS impairs tight junction protein arrangement and increases BBB permeability, which is associated with changes in locomotor activity, motor coordination and late-onset seizures.

(2R,6R)-hydroxynorketamine (HNK) reverses mechanical hypersensitivity in a model of localized inflammatory pain

The ketamine metabolite (2R,6R)-hydroxynorketamine, or (2R,6R)-HNK, was recently reported to evoke antinociception in response to a noxious thermal stimulus in healthy mice and reverse mechanical hypersensitivity in a murine model of neuropathic pain. This study reports the behavioral effects of (2R,6R)-HNK in male and female C57BL/6J mice exposed to a localized inflammatory pain condition and the broad pharmacological mechanism underlying this effect. Hind paw intraplantar injection of λ-carrageenan (CARR) caused inflammation and mechanical hypersensitivity in mice within 2 h, lasting at least 48 h. Administration of (2R,6R)-HNK (10–30 mg/kg i.p.) 2 h following CARR injection significantly reversed mechanical hypersensitivity within 1 h in male and female mice, and the effect persisted for 24 h following a single dose. The magnitude and timing of the analgesic effect of (2R,6R)-HNK were comparable to the non-steroidal anti-inflammatory drug carprofen. The reversal of hypersensitivity by (2R,6R)-HNK was blocked at 4 and 24 h after administration by pretreatment with the AMPA receptor antagonist NBQX and was not accompanied by changes in locomotor activity. These findings reinforce the growing evidence supporting (2R,6R)-HNK as a novel analgesic in multiple preclinical pain models and further support an AMPAR-dependent mechanism of action. SignificanceThe ketamine metabolite (2R,6R)-HNK reversed mechanical hypersensitivity associated with localized inflammation with onset less than 1 h and duration greater than 24 h, an effect comparable to the NSAID carprofen. Reversal of mechanical hypersensitivity by (2R,6R)-HNK is AMPAR-dependent.

MGlu2 mechanism-based interventions to treat alcohol relapse.

Recently we identified a deficiency in metabotropic glutamate receptor 2 (mGlu2) function in the corticoaccumbal pathway, as a common pathological mechanism underlying alcohol-seeking and relapse behavior. Based on this mechanism, we hypothesized that mGlu2/3 agonists and mGlu2 positive allosteric modulators (PAMs) may be effective in reducing relapse-like behavior. Two mGlu2/3 agonists, LY379268 and LY354740 (a structural analog of LY379268 six-fold more potent in activating mGlu2 over mGluR3), were tested in a well-established rat model of relapse, the alcohol deprivation effect (ADE) with repeated deprivation phases. Since these agonists do not readily discriminate between contributions of mGlu2 and mGluR3, we also tested LY487379, a highly specific PAM that potentiates the effect of glutamate on the mGlu2 with less specificity on other mGlu receptor subtypes. Both LY379268 and LY354740 significantly and dose-dependently reduced the expression of the ADE. No significant changes in water intake, body weight and locomotor activity were observed. Importantly, repeated administration of mGlu2/3 agonist did not lead to tolerance development. mGlu2 PAM LY487379 treatment significantly reduced expression of the ADE in both male and female rats. Combination treatment of mGlu2/3 agonist and PAM had similar effect on relapse-like drinking to that seen in mGlu2/3 agonist treatment alone. Together with other preclinical data showing that PAMs can reduce alcohol-seeking behavior we conclude that mGlu2 PAMs should be considered for clinical trials in alcohol-dependent patients.

Vortioxetine liposomes as a novel alternative to improve drug stability under stress conditions: toxicity studies and evaluation of antidepressant-like effect.

Vortioxetine hydrobromide (VXT), a new therapeutic option in the treatment of major depressive disorder, is a poorly soluble drug, and instability under stress conditions has been reported. The aim of the present study was to prepare VXT liposomes (VXT-Ls) with an antidepressant-like effect, to improve drug stability and reduce toxicity of the free drug. Liposomes were prepared using the thin lipid film hydration method and properly characterized. Forced degradation studies were conducted in photolytic and oxidative conditions. The cytotoxicity was evaluated in VERO cells through MTT assay and in vivo toxicity was assessed in mice. The antidepressant-like effect in mice was confirmed using the open-field test paradigm and tail suspension test. The optimized VXT-Ls have multilamellar vesicles with an average size of 176.74nm ± 2.43. The liposomal formulation increased the stability of VXT. VERO cell viability was maintained at around 40% when the VXT-Ls were tested at higher concentrations and no signs of acute toxicity were observed in mice. The antidepressant-like effect was effective, for VXT-Ls, at doses ranging from 2.5mg/kg to 10mg/kg, measured by the tail suspension test in mice. The non-liposomal formulation was effective at a dose of 10mg/kg. The open field test was performed and any unspecific changes in locomotor activity were revealed. Liposomes seem to be a promising alternative for an oral VXT formulation at lower doses (2.5mg/kg).

Innate immune stimulation prevents chronic stress-induced depressive and anxiogenic-like behaviors in female mice

It has been reported that pre-stimulation of the innate immune system can prevent depressive and anxiogenic-like behaviors in chronically stressed male mice. However, it is unclear whether similar effects can be observed in female animals. In the present study, we investigated this question in female mice. Our results showed that a single injection of lipopolysaccharide (LPS; 100 μg/kg) one day before stress exposure prevented increased immobility time in the tail suspension test and forced swimming test and decreased sucrose intake in the sucrose preference test in chronic unpredictable stress (CUS)-treated female mice. The single LPS pre-injection (100 μg/kg) prevented the CUS-induced decrease in (i) time spent in open arms and number of entries into open arms in the elevated plus maze test, (ii) time spent in lit side in the light-dark test, and (iii) time spent in the central region of the open field in the open field test, along with no changes in locomotor activity. It was also found that the single LPS pre-injection in female mice prevented the CUS-induced increase in the expression levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6 mRNA in the hippocampus and medial prefrontal cortex. Inhibition of innate immune system stimulation by minocycline pretreatment abrogated the preventive effect of LPS on CUS-induced depressive and anxiogenic-like behaviors and neuroinflammatory responses in the hippocampus and medial prefrontal cortex in female mice. These results suggest that pre-stimulation of the innate immune system by LPS injection may prevent the development of behavioral abnormalities in female mice.

Synergistic antidepressant effects of citalopram and SB-334867 in the REM sleep-deprived mice: Possible role of BDNF

This study was done to evaluate the effect of co-treatment of orexin agents along with citalopram on the modulation of depression-like behavior and the expression of BDNF in the prefrontal cortex (PFC) of sleep-deprived male mice. A sleep deprivation model was performed in which rapid eye movement (REM) sleep was completely prohibited, and non-REM sleep was intensely reduced for 24 h. For drug microinjection, the guide cannula was surgically fixed in the left lateral ventricle of mice. Furthermore, we used the open-field test (OFT), forced swim test (FST), tail suspension test (TST), and splash test for recording depression-like behavior as well as Real-Time PCR amplification for assessing the expression of BDNF in the PFC of REM sleep-deprived mice. Our results revealed that REM sleep deprivation did not change locomotor activity while increased depressive-like behavior in FST, TST, and splash tests. However, the expression of BDNF was decreased in the PFC. Intraperitoneally (i.p.) administration of citalopram induced antidepressant effect in the normal and REM sleep-deprived mice. Moreover, intracerebroventricular (i.c.v.) microinjection of a non-effective dose of SB-334867, an orexin antagonist, potentiated the antidepressant-like effect of citalopram.On the other hand, a non-significant dosage of orexin-1 reversed the antidepressant effect of citalopram in the normal and REM sleep-deprived animals. Furthermore, our results showed that injection of citalopram alone or with SB-334867 increased the mRNA expression level of BDNF in the PFC of REM sleep-deprived mice. These data suggest that REM sleep deprivation interferes with the neural systems underlying the depression-like process and supports a likely interaction of the orexin system with citalopram on the modulation of depression-like behavior in REM sleep-deprived mice.

Innate responses to con‐ and heterospecific alarm chemicals in juveniles of a freshwater shrimp

AbstractReleased substances from injured conspecifics and heterospecifics (alarm chemicals) often trigger inducible defenses (e.g., behavioral, morphological, and life‐history antipredator defenses). Although there are good reasons to assume that the detection of damage‐release chemicals may be inherited, immediate behaviors to alarm chemicals remain to be assessed in many aquatic taxa. This study examines changes in locomotor activity in juveniles of a freshwater shrimp, Palaemon argentinus, in response to (1) distilled water; (2) macerated adult conspecifics, and (3) macerated adult heterospecifics (a closely related, non‐coexisting species). We tested three sets of juveniles coming from (1) alarm cues‐unexposed mothers (naïve juveniles), (2) mothers exposed to macerated conspecifics, and (3) mothers exposed to macerated heterospecifics. Juveniles were tested for changes in locomotor activity before and after the addition of a corresponding stimulus. Locomotor activity of naïve juveniles decreased in response to con‐ and heterospecific stimuli, while it did not change in response to distilled‐water controls. Effect size, as Cohen's dRM (the standard mean difference between the pre‐ and the post‐stimulus period using the pooled standard deviation) indicated that the reduction in locomotor activity was strong in response to conspecific stimulus (dRM = −1.521), but it was moderate in response to heterospecific stimulus (dRM = −0.682). While the responses of naïve juveniles indicate an innate recognition of alarm substances, the responses to heterospecifics likely arise from the recognition of chemicals with a molecular structure partly conserved between related species, as predicted by the phylogenetic relatedness hypothesis. Furthermore, juveniles from treated mothers behaved differently than the naïve ones, suggesting that juvenile behavioral traits were modified through embryonic experience. As the embryonic exposure to alarm cues occurs during embryogenesis, we assume that the mothers have perceived these cues also, which might have caused part of the observed developmental effects.

Involvement of kynurenine pathway and N-methyl-d-aspartate receptors in the antidepressant-like effect of vilazodone in the tail suspension test in mice

The present study evaluated the antidepressant-like effects of vilazodone using the tail suspension test in mice. We also investigated the contribution of kynurenine pathway and N-methyl-d-aspartate receptors to this effect. For this purpose, we pretreated animals with sub-effective doses of L-kynurenine, 3-hydroxykynurenine, or quinolinic acid. We then assessed the immobility time, an indicative measure of depressive-like behavior, in the tail suspension test. We also evaluated the possible effects of sub-effective doses of vilazodone combined with sub-effective doses of ketamine (N-methyl-d-aspartate receptor antagonist) in a separate group. Vilazodone (3mg/kg, intraperitoneal) significantly reduced immobility time in the tail suspension test. L-kynurenine (1.7 mg/kg, intraperitoneal), 3-hydroxykynurenine (10 mg/kg, intraperitoneal), and quinolinic acid (3 nmol/site, intracerebroventricular) significantly increased the immobility time in the tail suspension test. The antidepressant-like effects of vilazodone (3mg/kg, intraperitoneal) were inhibited by pre-treatment with non-effective doses of L-kynurenine (0.83 mg/kg, intraperitoneal), 3-hydroxykynurenine (3.33 mg/kg, intraperitoneal), or quinolinic acid (1 nmol/site, intracerebroventricular). Pretreatment of mice with sub-effective doses of ketamine (1 mg/kg, intraperitoneal) optimized the action of a sub-effective dose of vilazodone (0.3mg/kg, intraperitoneal) and reduced the immobility time in the tail suspension test. None of the drugs used in this study induced any changes in locomotor activity in the open field test. The results showed that vilazodone induced an antidepressant-like effect in the tail suspension test, which may be mediated through an interaction with the kynurenine pathway and N-methyl-d-aspartate receptors.

Bmal1-knockout mice exhibit reduced cocaine-seeking behaviour and cognitive impairments

Brain and Muscle Arnt-like Protein 1 (BMAL1) is an essential component of the molecular clock underlying circadian rhythmicity. Its function has been recently associated with mood and reward processing alterations. We investigated the behavioural and neurobiological impact of Bmal1 gene deletion in mice, and how this could affect rewarding effects of cocaine. Additionally, key clock genes and components of the dopamine system were assessed in several brain areas. Our results evidence behavioural alterations in Bmal1-KO mice, including changes in locomotor activity with impaired habituation to environments, short-term memory and social recognition impairments. In addition, Bmal1-KO mice experienced reduced cocaine-induced sensitisation and rewarding effects of cocaine as well as reduced cocaine-seeking behaviour. Furthermore, Bmal1 deletion influenced the expression of other clock-related genes in the mPFC and striatum, as well as alterations in the expression of dopaminergic elements. Overall, the present article offers a novel and extensive characterisation of Bmal1-KO animals. We suggest that reduced cocaine's rewarding effects in these mutant mice might be related to Bmal1 role as an expression regulator of MAO and TH, two essential enzymes involved in dopamine metabolism.

P-550 Transgenerational epigenetic influences of maternal circadian rhythm changes during pregnancy and lactation periods on cognition and behavior in male offspring

Abstract Study question Do maternal circadian rhythm changes during pregnancy and lactation periods cause transgenerational behavioral and cognitive alterations in male offspring? Summary answer Maternal circadian rhythm changes cause impaired behavioral alterations such as motor activity impairments, increased anxiety and weakening of spatial memory in male offspring. What is known already The circadian system regulates the daily temporal organization in behavior and physiology in most species. Recent publications in model systems have emphasized the negative effects of circadian rhythm disruption on both female and male reproduction and fertility. There is growing concern about the long-term effects of circadian rhythm disruptions during pregnancy and lactation periods on human offspring and their descendants as circadian regulation during these periods can potentially alter epigenetic programing in offspring. However, there is a lack of information about the possible transgenerational effects of circadian rhythm disorders for the health of offspring in the literature. Study design, size, duration Male offspring from pregnant Wistar rats (n = 60) which were exposed to control (12 hours light/12 hours dark), short day (SD) (8 hours light/16 hours dark) or long day (LD) periods (16 hours light/8 hours dark) during only pregnancy, only lactation or both periods (n = 15/group) categorized as control, SD pregnancy (SD-P), SD lactation (SD-L), SD pregnancy and lactation (SD-P+L), LD pregnancy (LD-P), LD lactation (LD-L), LD pregnancy and lactation (LD-P+L) groups. Participants/materials, setting, methods The length of gestation, litter size, sex ratio of pups (fraction male) and birth weights were recorded. The maternal locomotor activity and anxiety were analyzed by open field (OF) and elevated plus maze (EPM) tests, respectively (n = 15 mothers/group). Learning and memory, locomotor activity and anxiety related changes were studied in the male offspring in pre-pubertal, pubertal and adult periods with object localization (OL) and Morris water maze (MWM), OF and EPM tests, respectively. Main results and the role of chance Newborn weights was significantly increased in SD (5.01±0.07) and LD (4.47±0.29) groups compared to control group (3.73±0.03) (p < 0.001). Male sex ratio of pups born to mothers on SD schedule was unusually low (0.21±0.62) compared to mothers on normal light schedule (0.48±0.05) (p < 0.001). The gestation length was not altered. Locomotor activity was increased in mothers exposed to SD schedule (p < 0.01). A significant motor activity impairment in the prepubertal period was remarkable in SD-P+L, LD-P, LD-L and LD-P+L groups (p < 0.001). Compared to control group, EPM test showed that all the offspring in SD groups had significant increase in their anxiety in the prepubertal period. Motor functions that decreased before puberty seems gradually improved at adulthood. Weakened short-term spatial memory was observed at puberty, especially in SD-P (p < 0.001), SD-P+L (p < 0.05), LD-P (p < 0.05) groups. Time to find the platform was significantly higher than those measured for control group for SD-P-L (p < 0.001) in the prepubertal period and LD-P+L group (p < 0.001) in the pubertal period meaning decreased spatial memory and learning. A probe trial given on day 6 with MWM test showed that LD groups had no alterations in spatial memory whereas SD-P (p < 0.05) and SD-G+L (p < 0.001) groups showed impaired changes in long-term spatial memory. Limitations, reasons for caution Due to limitations of working with human subjects exposed to shift work schedules, most chronoregulation research including ours has used rodent models with limitations in translating to human studies. However, to truly know if such concerns apply to humans will require retrospective and prospective human studies. Wider implications of the findings Epigenetic transitions are crucial for transcriptional reprogramming triggered by environmental cues. Our study might provide valuable information regarding transgenerational effects of maternal chronodisruption on health later in life of the offspring, particularly at prepubertal and pubertal periods, create suggestions and guidelines for reproductive biology, shift work and possible infertility problems. Trial registration number This work was supported by research grants from the Scientific and Technological Research Council of Turkey (TUBITAK) (SBAG 219S636) and Akdeniz University, The Scientific Research Projects Coordination Unit (TYL-2018-3580).

Protective effect of vitamin C on DNA damage in surgery-induced cognitive dysfunction in APP/PS1 mice

Postoperative cognitive impairment is more likely to occur in elderly patients and in those with neurodegenerative diseases. The mechanisms underlying this impairment include neuroinflammation and oxidative stress. The increase in reactive oxygen species during oxidative stress causes cellular and molecular injury to neurons, including DNA damage, which aggravate brain dysfunction. Vitamin C has antioxidant effects and improves cognitive function in patients with Alzheimer’s disease. However, it is unclear whether it can ameliorate surgery-induced cognitive impairment by inhibiting oxidative stress. In this study, 6-month-old mice overexpressing mutant amyloid precursor protein and presenilin-1 (APP/PS1) were subjected to laparotomy. The open field and fear conditioning tests were used to assess cognitive function. Mice that underwent surgery showed cognitive impairment without changes in spontaneous locomotor activity. Oxidative stress, DNA damage and inflammatory mediators were increased in the hippocampus after surgery. The expression levels of non-homologous end-joining DNA repair-associated proteins, including Ku heterodimer, DNA-dependent protein kinase catalytic subunit, X-ray repair cross complementing 4 (XRCC4) and XRCC4-like factor, were increased after surgery. Vitamin C pretreatment effectively attenuated cognitive dysfunction induced by surgery and reduced oxidative stress and DNA damage. Our findings suggest that DNA damage plays an important role in surgery-induced cognitive dysfunction, and that vitamin C pretreatment may have therapeutic potential as a preventative approach for the cognitive impairment.

Alterations in gut microbiota affect behavioral and inflammatory responses to methamphetamine in mice.

Methamphetamine (METH) is a highly addictive and widely abused drug that causes severe neuroinflammation in the human brain. The gut microbiota has a tremendous impact on the core symptoms of neuropsychiatric disorders via the microbiota-gut-brain (MGB) axis. However, it is not clear whether alterations in the gut microbiota are involved in METH exposure. We established a mouse model with chronic, escalating doses of METH exposure. Intervene in gut microbiota with antibiotics to observe the changes of locomotor activity caused by METH exposure in mice. qPCR and 16S rRNA gene sequencing were used to analyze the gut microbiota profiles. In addition, we tested the levels of inflammatory factors in the nucleus accumbens (NAc), prefrontal cortex (mPFC), hippocampus (HIp), and spleen. Finally, short-chain fatty acids (SCFAs) were supplemented to determine the interaction between behavior changes and the structure of gut microbiota. In this research, METH increased the locomotor activity of mice, while antibiotics changed the effect. Antibiotics enhanced the expression of pro-inflammatory cytokines in mPFC, HIp, and spleen of METH-exposed mice. METH altered the gut microbiota of mice after antibiotic treatment, such as Butyricicoccus and Roseburia, which are related to butyrate metabolism. Supplementation with SCFAs changed the behavior of METH-exposed mice and decreased Parabacteroides and increased Lactobacillus in METH-exposed mice gut. This research showed that antibiotics affected the behavior of METH-exposed mice and promoted inflammation. Our findings suggest that SCFAs might regulate METH-induced gut microbiota changes and behavior.

Acute Cannabigerol Administration Lowers Blood Pressure in Mice

Cannabigerol (CBG) is a cannabinoid compound that is synthesized from Cannabis sativa L. and acts as a substrate for both Δ9‐tetraydrocannabinol (Δ9‐THC) and cannabidiol (CBD) formation. Given that it does not exhibit psychoactive effects, emerging research has focused on CBG as a potential therapeutic for health conditions including algesia, epilepsy, anxiety, and cancer. While CBG can bind to cannabinoid receptors CB1 and CB2, it has also been described as an agonist at α2‐adrenoreceptors (A2‐AR), which when activated inhibit the release of norepinephrine from α‐adrenergic neurons. This raises the concern that CBG could act at A2‐AR to reduce norepinephrine release to cardiovascular end organs, such as the heart and kidneys, causing a reduction in blood pressure. Despite this possibility, there are no reports examining cardiovascular effects of CBG. In this study, we tested the hypothesis that acute CBG administration can lower blood pressure. To test this, six male C57BL/6J mice underwent surgery at 8‐10 weeks of age to implant a radiotelemetry probe, which allows for continuous measurement of blood pressure, heart rate and locomotor activity in conscious, freely moving mice. Following 10 days of recovery, baseline measurements were obtained and then mice were randomized to receive intraperitoneal injections of CBG (3.3, 5.6, and 10 mg/kg) and vehicle in a crossover design, with at least one‐week washout between treatments. Changes in blood pressure, heart rate, and locomotor activity were measured for two hours post‐injection. We found that acute CBG significantly lowered blood pressure compared with vehicle (‐12±5 mmHg vehicle vs. ‐28±2 mmHg at 10 mg/kg CBG; p=0.018), with no apparent dose responsiveness at the doses used in this study (‐22±2 mmHg at 3.3 mg/kg CBG; ‐28±4 at 5.6 mg/kg CBG). The greatest blood pressure reduction was seen at 90‐minutes post‐CBG administration, which is consistent with reports for peak plasma concentrations of this compound in rodents. The blood pressure lowering effects of CBG occurred in the absence of changes in heart rate or locomotor activity. These overall findings suggest acute CBG may lower blood pressure in phenotypically normal young adult male mice, which may provide caution for the potential of hypotension as an adverse effect of CBG administration. Additional studies are needed to determine if the blood pressure lowering effects of CBG are via an A2‐AR mechanism.

Comparative study of the effects of adamantane derivatives on the behavior of CD-1 mice with different phenotype of attention stability

The effect of memantine (1 and 10 mg/kg/day), ladasten (50 mg/kg/day) and cyclantane (10 mg/kg/day) on the behavior of CD-1 mice differing in the phenotype of attention stability in the "closed enriched cross maze" test after three days of intraperitoneal administration was studied. It was found that in a subpopulation of mice with an initial attention deficit, these aminoadamantane derivatives partially restored the level of attention. The drugs equally worsened attention in a subpopulation with an initially high attention index by 40–47 % relative to the control, which indicates the absence of selectivity of the effect of these drugs with respect to attention deficit. However, this effect was not accompanied by a change in exploratory and locomotor activity, which makes it possible to make an assumption about the prospects for further study of the pharmacological effects of adamantane derivatives and optimization of their dose and duration of administration.

Cardiomyocyte‐specific deletion of sarcoglycan‐δ leads to dilated cardiomyopathy, autonomic dysfunction, and exaggerated stress‐induced cardiovascular reactivity

Deficiency of sarcoglycan‐δ (Sgcd) induces disruption of the dystrophin glycoprotein complex, resulting in loss of membrane stability. We have reported that angiotensin II (AngII)‐mediated autonomic dysfunction precedes and predicts development of dilated cardiomyopathy (DCM) in the global Sgcd‐deficient mice [Exp Physiol 2015].The relative contribution of cardiomyocyte‐targeted Sgcd on DCM and autonomic dysfunction remains unknown. Our goal is to determine whether cardiac remodeling in the Sgcd mutations is an intrinsic process of the cardiomyocytes. We have also observed that global Sgcd‐deficient mice with DCM exhibit anxiety‐like behaviors. AngII via type 1 receptors (AT1R) is well‐known to mediate anxiety‐related behaviors, while Ang‐(1‐7) via Mas receptors is anxiolytic. Thus, we hypothesize that Sgcd in the ventricular myocytes is essential for the progression of DCM, and to elicit emotional stress responses. Cardiac‐specific Sgcd‐deficient (cSgcd‐KO) and littermate control (WT) mice were generated by breeding male αMHCcre+(αmyosin‐heavy chain Myh6 promoter drives expression of the cre‐recombinase) withfemaleglobal Sgcd‐deficientmice. Absence of Sgcdin the cardiomyocytes was confirmed by immunohistochemistry and qPCR in the cSgcd‐KO mice. WT (n=11) and cSgcd‐KO (n=14) mice were echoed every month, from 8 weeks of age, to monitor progression of DCM. At ~35 weeks of age, telemeters (DSI) were implanted to measure changes in blood pressure (BP), heart rate (HR) and locomotor activity during acute emotional stress challenge (20 min exposure to predator odor). Autonomic indices including baroreflex sensitivity (BRS, sequence technique), and resting cardiac vagal and sympathetic tone (HR responses to atropine and propranolol, respectively) were calculated. At 36±1 weeks of age, cSgcd‐KO mice exhibit 62% increase in left ventricular (LV) end‐diastolic volume, 58% decrease in LV ejection fraction, and increased cardiac fibrosis (p<0.05 vs. 10 weeks of age). At baseline, cSgcd‐KO mice exhibit lower BP (100±6 vs.121±1 mmHg), reduced BRS (0.72±0.08 vs.2.01±0.05 ms/mmHg) and vagal tone (∆HR= +32±6 vs. +151±18 bpm), and increased sympathetic tone (∆HR= ‐212±12 vs. ‐123±10 bpm) (p<0.05 vs.WT). Paradoxically, given increased basal sympathetic tone and decreased basal vagal tone, stress caused hypotension in the cSgcd‐KO mice with DCM, likely due to reduced cardiac output. This is accompanied by profound increase in AT1R, and reduced expression of Mas and MrgD receptors (ligand for newly identified heptapeptide alamandine) in LV and brainstem (p<0.0001‐0.01 vs. baseline and WT). We conclude ‐ (i) Sgcddeleted exclusively from the cardiac myocytes creates a novel transgenic mouse strain that develops DCM at ~35 weeks of age. (ii) Stress‐evoked profound changes in CNS and systemic hemodynamics occur directly or indirectly, and cannot be ascribed to Sgcd loss in vascular smooth muscle, endothelium, neurons, or astrocytes. (iii) Contributions of the renin‐angiotensin system is pivotal in pathophysiology of Sgcd deficiencies.

Recapitulation of Retinal Damage in Zebrafish Larvae Infected with Zika Virus.

Zebrafish are increasingly being utilized as a model to investigate infectious diseases and to advance the understanding of pathogen–host interactions. Here, we take advantage of the zebrafish to recapitulate congenital ZIKV infection and, for the first time, demonstrate that it can be used to model infection and reinfection and monitor anti-viral and inflammatory immune responses, as well as brain growth and eye abnormalities during embryonic development. By injecting a Brazilian strain of ZIKV into the yolk sac of one-cell stage embryos, we confirmed that, after 72 h, ZIKV successfully infected larvae, and the physical condition of the virus-infected hosts included gross morphological changes in surviving embryos (84%), with a reduction in larval head size and retinal damage characterized by increased thickness of the lens and inner nuclear layer. Changes in locomotor activity and the inability to perceive visual stimuli are a result of changes in retinal morphology caused by ZIKV. Furthermore, we demonstrated the ability of ZIKV to replicate in zebrafish larvae and infect new healthy larvae, impairing their visual and neurological functions. These data reinforce the deleterious activity of ZIKV in the brain and visual structures and establish the zebrafish as a model to study the molecular mechanisms involved in the pathology of the virus.

EFFECT OF MINOCYCLINE AND MINOSCYCLINE+METFORMIN ON DIABETES-RELATED DEPRESSION

Objective: Minocycline is a second-generation tetracycline group antibiotic that acts on the central nervous system. Minocycline reduces microglial activation and has anti-inflammatory, anti-apoptotic, and antioxidant properties. Recently, it has been proposed that there is a bidirectional relationship between diabetes and depression and that inflammation is one of the common pathways in their pathophysiology. The effects of minocycline on depression were then investigated. This study aimed to reveal the effects of minocycline alone or in combination with metformin, which is used in the treatment of diabetes, on diabetes-related depression. Material and Method: For this purpose, to establish a human-like type 2 diabetes model in mice, streptozotocin (STZ) (50mg/kg) was administered once a day for five consecutive days after a 4-week high-fat diet. Animals with blood glucose levels ≥200 mg/dl were considered diabetic and employed in this experiment. Minocycline (40 mg/kg), fluoxetine (20 mg/kg), and metformin (200 mg/kg) were given once a day for 7 days two weeks after STZ injection. After the drug injections were completed, an open field test was used to determine locomotor activity and a forced swimming test was used to determine depression level. Result and Discussion: It was concluded that diabetes and the drugs administered did not induce a significant change in locomotor activity, and that the minocycline and minocycline-metformin combination was at least as effective as fluoxetine in treating depression. It is recognized that the initiation of antidepressant effects in a short period is critical for patient adherence to therapy and diabetes prognosis. In conclusion, antidepressant-like effects of subchronic minocycline treatment appear to be potent as classical antidepressants. The mechanisms underlying minocycline's effects on mood should be broadly investigated to increase our understanding of depression and unveil potential novel therapies in depression management.

Modulation of Metabolic Hormone Signaling via a Circadian Hormone and Biogenic Amine in Drosophila melanogaster.

In insects, adipokinetic hormone is the primary hormone responsible for the mobilization of stored energy. While a growing body of evidence has solidified the role of adipokinetic hormone (AKH) in modulating the physiological and behavioral responses to metabolic stress, little is known about the upstream endocrine circuit that directly regulates AKH release. We evaluated the AKH-producing cell (APC) transcriptome to identify potential regulatory elements controlling APC activity and found that a number of receptors showed consistent expression levels, including all known dopamine receptors and the pigment dispersing factor receptor (PDFR). We tested the consequences of targeted genetic knockdown and found that APC limited expression of RNAi elements corresponding to each dopamine receptor and caused a significant reduction in survival under starvation. In contrast, PDFR knockdown significantly extended lifespan under starvation, whereas expression of a tethered PDF in APCs resulted in significantly shorter lifespans. These manipulations caused various changes in locomotor activity under starvation. We used live-cell imaging to evaluate the acute effects of the ligands for these receptors on APC activation. Dopamine application led to a transient increase in intracellular calcium in a trehalose-dependent manner. Furthermore, coapplication of dopamine and ecdysone led to a complete loss of this response, suggesting that these two hormones act antagonistically. We also found that PDF application led to an increase in cAMP in APCs and that this response was dependent on expression of the PDFR in APCs. Together, these results suggest a complex circuit in which multiple hormones act on APCs to modulate metabolic state.