Reduced Locomotor Activity Research Articles

Individual Behavioral Syndromes and Shoal Characteristics in Farmed and Wild Acrossocheilus fasciatus

This study investigates the individual behavioral syndromes and shoal characteristics of farmed and wild populations of the cyprinid Acrossocheilus fasciatus to elucidate the factors influencing the efficacy of fish stock enhancement. We examined two wild populations from Quzhou and Lishui, in Zhejiang Province, China, and one farmed population from the same geographical location as the Quzhou wild population. Individual behavioral syndromes were thoroughly evaluated alongside shoal characteristics. Results indicated that farmed A. fasciatus exhibited greater boldness, exploratory behavior, and sociability compared to their wild counterparts. Wild populations demonstrated distinct behavioral traits, with the Quzhou population showing reduced locomotor activity and sociability, and the Lishui population displaying timidity. Shoal analysis revealed that wild fish had higher cohesion and shoal synchronization compared to farmed fish. Additionally, mixed groups exhibited intermediate locomotor behaviors but decreased cohesion, particularly in the Quzhou population. These findings underscore significant behavioral differences between farmed and wild fish, as well as among wild fish from different geographical locations, emphasizing the need for tailored training and environmental modifications in stock enhancement programs to improve survival.

Potassium Release From the Habenular Astrocytes Induces Depressive-Like Behaviors in Mice.

The habenula has been implicated in psychiatric disorders such as depression, primarily because of its role in the modulation of the dopaminergic and serotonergic systems, which play a role in the pathophysiology of these disorders. Despite growing evidence supporting the role of the habenula in behavioral regulation, the process by which neural cells develop in the habenula remains elusive. Since the habenular anlage is found in the prosomere 2 domain expressing transcription factor Dbx1 in mouse embryos, we hypothesized that the Dbx1-expressing prosomere domain is a source of astrocytes that modulate neuronal activity in the habenula. To address this, we examined the cell lineage generated from Dbx1-expressing cells in male mice using tamoxifen-inducible Cre recombinase under the control of the Dbx1 promoter. Perinatal induction of Cre activity labeled cells migrating radially from the ventricular zone to the pial side of the habenular anlage, and eventually showed astrocyte-like morphology with expression of the marker protein, S100β, for mature astrocytes in the habenula of the adult mouse. Photostimulation of astrocytes expressing ChR2 released potassium ions into the extracellular space, which in turn excited the neurons with an increased firing rate in the lateral habenula. Finally, photostimulation of habenular astrocytes exacerbated depression-like phenotypes with reduced locomotor activity, exaggerated despair behavior and impaired sucrose preference in open-field, tail suspension and sucrose preference tests, respectively. These results indicated that the Dbx1-expressing perinatal domain generated astrocytes that modulated neuronal activity via the regulation of extracellular potassium levels.

Abstract 4135662: Dietary Inulin Improves Glucose Metabolism and Energy Balance in Obese Mice via Adipocyte Free Fatty Acid Receptor 2 (FFAR2)

Background: Inulin is a non-digestible prebiotic dietary fiber that can promote metabolic health including reduced body weight and improved glucose metabolism via effects on gut microbiota. We hypothesize that inulin prevents obesity-associated cardiometabolic alterations by augmenting the production of short-chain fatty acids (SCFA) from gut microbiota, which activate free fatty acid receptor 2 (FFAR2), a major SCFA receptor, in murine adipose tissue. Methods: 8-week-old male C57BL/6J (wild-type, WT; n=34) and adipocyte FFAR2-knockout (Ad-FFAR2 KO; n=25) mice were fed a high-fat high-sucrose (HFHS) diet for 8 weeks, then randomized into experimental groups to receive either continued HFHS (n=8-13), or HFHS containing inulin (10% w/w chicory root inulin; n=17-21) for a further 5 weeks. Body weight was recorded weekly, food intake, body composition, and indirect calorimetry were assessed before and after the inulin intervention, and intraperitoneal glucose and insulin tolerance tests were performed. Subcutaneous and visceral white adipose tissue (WAT) samples were collected at the study termination. Results: HFHS-fed Ad-FFAR2 KO mice showed higher body weight (7.4%), fat mass, and WAT weight due to increased food intake, with worse glucose tolerance compared to WT mice. In WT mice, inulin significantly reduced body weight gain and body adiposity. These effects were associated with reduced locomotor activity and respiratory quotient (RQ) without effects on energy expenditure and were accompanied by improvements in glucose tolerance. Strikingly, inulin had no effect on body weight or body adiposity in Ad-FFAR2 KO mice but reduced RQ, locomotor activity, and improved glucose tolerance similar to WT mice. Conclusions: Our findings suggest that FFAR2 signaling in adipose tissue is crucial for improving cardiometabolic outcomes in obesity and that gut metabolites responsive to dietary interventions, such as inulin, are potential targets for obesity treatment strategies.

Chronic corticosterone exposure causes anxiety- and depression-related behaviors with altered gut microbial and brain metabolomic profiles in adult male C57BL/6J mice

Chronic exposure to glucocorticoids in response to long-term stress is thought to be a risk factor for major depression. Depression is associated with disturbances in the gut microbiota composition and peripheral and central energy metabolism. However, the relationship between chronic glucocorticoid exposure, the gut microbiota, and brain metabolism remains largely unknown. In this study, we first investigated the effects of chronic corticosterone exposure on various domains of behavior in adult male C57BL/6J mice treated with the glucocorticoid corticosterone to evaluate them as an animal model of depression. We then examined the gut microbial composition and brain and plasma metabolome in corticosterone-treated mice. Chronic corticosterone treatment resulted in reduced locomotor activity, increased anxiety-like and depression-related behaviors, decreased rotarod latency, reduced acoustic startle response, decreased social behavior, working memory deficits, impaired contextual fear memory, and enhanced cued fear memory. Chronic corticosterone treatment also altered the composition of gut microbiota, which has been reported to be associated with depression, such as increased abundance of Bifidobacterium, Turicibacter, and Corynebacterium and decreased abundance of Barnesiella. Metabolomic data revealed that long-term exposure to corticosterone led to a decrease in brain neurotransmitter metabolites, such as serotonin, 5-hydroxyindoleacetic acid, acetylcholine, and gamma-aminobutyric acid, as well as changes in betaine and methionine metabolism, as indicated by decreased levels of adenosine, dimethylglycine, choline, and methionine in the brain. These results indicate that mice treated with corticosterone have good face and construct validity as an animal model for studying anxiety and depression with altered gut microbial composition and brain metabolism, offering new insights into the neurobiological basis of depression arising from gut-brain axis dysfunction caused by prolonged exposure to excessive glucocorticoids.

Neuroprotective Roles of Lauric Acid and Resveratrol: Shared Benefits in Neuroinflammation and Anxiety, Distinct Effects on Memory Enhancement.

Neuroinflammation can be triggered by a high-fat/high-fructose diet (HFFD), and CD36 may be an underlying mechanism. Lauric acid (LA), the major fatty acid in coconut oil, and resveratrol, the plant-based polyphenolic compound, may exert anti-inflammatory effects. Therefore, this study investigated the possible effects of LA and resveratrol on diet-induced neuroinflammation and CD36. Healthy male C57BL/6 mice (8 weeks of age, n = 31) were fed a control diet (10%kcal fat) or diets containing high fat (60%kcal fat) and fructose (5% w/v fructose drinking water) for 6 weeks, ad libitum. Supplemented to the HFFD, mice daily received resveratrol (7.5 mg/kg) (HFFD-RSV) or LA (750 mg/kg) (HFFD-LA). At the end of the study, HFFD resulted in anxiety-like behavior, reduced locomotor activity, neuroinflammation (increased brain GFAP, IL-6, MCP-1, IFN-γ, TNF-α), and systemic inflammation (increased plasma GFAP, IFN-γ, TNF-α, IL-12p70, reduced plasma IL-10). HFFD-RSV and HFFD-LA alleviated HFFD-induced anxiety-like behavior, neuroinflammation, and systemic inflammation. HFFD-LA improved memory. Brain and plasma CD36 levels were increased by HFFD and reduced by HFFD-RSV or HFFD-LA. Dietary resveratrol and LA intake may alleviate HFFD-induced neuroinflammation, systemic inflammation, and anxiety-like behavior and improve memory, as CD36 may be an underlying mechanism.

Purkinje cell hyperexcitability and depressive-like behavior in mice lacking erg3 (ether-à-go-go-related gene) K+ channel subunits.

Potassium channels stabilize the resting potential and neuronal excitability. Among them, erg (ether-à-go-go-related gene) K+ channels represent a subfamily of voltage-gated channels, consisting of erg1, erg2, and erg3 subunits; however, their subunit-specific neuronal functions in vivo are barely understood. To find erg3- and erg1-mediated functions, we generated global Kcnh7 (erg3) and conditional Kcnh2 (erg1) knockout mice. We found that erg3 channels stabilize the resting potential and dampen spontaneous activity in cerebellar Purkinje cells (PCs) and hippocampal CA1 neurons, whereas erg1 channels have suprathreshold functions. Lack of erg3 subunits induced hyperexcitability with increased action potential firing in PCs, but not in CA1 neurons. Notably, erg3 depletion caused depressive-like behavior with reduced locomotor activity, strongly decreased digging behavior, and shorter latencies to fall off a rotating wheel, while learning and memory remained unchanged. Our data show that erg K+ channels containing erg3 subunits mediate a neuronal subthreshold K+ current that plays important roles in the regulation of locomotor behavior in vivo.

Evaluation of Anxiolytic Activity of Angiotensin Receptor Blockers Using Actophotometer Test in Wistar Rats.

Introduction Anxiety disorders are common mental illnesses impacting quality of life, with current treatments like benzodiazepines andselective serotonin reuptake inhibitors (SSRIs)facing limitations due to side effects. Angiotensin receptor blockers (ARBs), used primarily for hypertension, have shown potential neuropsychiatric benefits, including anxiolytic effects. This study explores the anxiolytic effects of two ARBs, telmisartan and losartan, by evaluating locomotor activity in Wistar rats, aiming to identify new treatment options for anxiety through modulation of the renin-angiotensin system. Aim To evaluate the anxiolytic activity of telmisartan and losartan in experimental Wistar rats. Materials and methods The study was carried out afterconsent was obtained from the Institutional Animal Ethics Committee (IAEC). The rats were divided into four groups: group 1 (control group) received distilled water (2 ml/kg), group 2 (diazepam 2 mg/kg group) received diazepam (2 mg/kg), group 3 (telmisartan 5 mg/kg group) received telmisartan (5 mg/kg), and group 4 (losartan 5 mg/kg group) received losartan (5 mg/kg). The actophotometer test, which measures the locomotor activity levels of rats, was utilized to evaluate their anxiolytic activity. The percent decrease in locomotor activity was calculated for statistical evaluation. Results Our investigation found that the telmisartan 5 mg/kg and losartan 5 mg/kg groups had considerable anxiolytic activity (p<0.05) compared to the control group, and it was comparableto the diazepam 2 mg/kg (p>0.05) group. Conclusion The findings of our study indicate that ARBs, specifically telmisartan 5 mg/kg and losartan 5 mg/kg, exhibit potential anxiolytic effects, evidenced by a significant reduction in locomotor activity in the actophotometer test. These results imply that ARBs could be considered as possible therapeutic agents for anxiety, providing a new perspective on their use beyond traditional cardiovascular applications.

Molecular and immunohistochemical alterations in fluoride-induced neurological impediment in adult rats

SummaryThis study highlights the potential neurotoxic and impaired behavioral effects associated with high fluoride concentrations in drinking water. PurposeFluoride is known to cause neurotoxicity, evinced by lower I.Q. levels in children from high-fluoride regions as compared to those in low-fluoride regions. Thus, the present study was designed to investigate the molecular mechanism behind the neurological and behavioural changes induced by sodium fluoride in Wistar rats. Material and methodsA total of 24 female Wistar rats, aged six weeks and weighing approximately 150–220 g, were randomly divided into three groups: Group I (control) received reverse osmosis (R.O.) water, Group II received Sodium Fluoride (NaF) at 10 ppm, and Group III received NaF at 50 ppm in their drinking water for 60 days. The animals underwent behavioural tests including the Forced Swim Test (F.S.T.), Open Field Test (OFT), and Novel Object Recognition Test (N.O.R.T.), to assess any alterations in behaviour. After 60 days, the animals were euthanized, and their blood and brain samples were analysed to evaluate biochemical changes by Western Blot/I.H.C. analysis of B.A.X., Bcl2, LC3B, TLR4, PARP1, p53, Caspase, α-Synuclein, PARKIN, NeuN, KI67, DNM-1, and M.F.N. for assessing molecular pathways for toxicity. ResultsImpaired locomotion, memory impairment, and behaviour resembling depression in the animals were evinced by reduced mobility index in the F.S.T., discrimination index in the N.O.R.T., and reduced locomotor activity in the open field test results. Additionally, alterations in antioxidant levels and oxidative stress parameters were observed in the brain. The expression levels of various apoptotic and inflammatory biomarkers (B.A.X., Bcl2, TLR4, PARP1, p53, and Caspase) showed apoptosis in neurons. The confocal studies showed increased expression of inflammatory (α-Synuclein, PARKIN), apoptotic (LC3B, B.A.X., p53, KI67), and mitochondrial dysfunction (NeuN, DNM-1, M.F.N.) markers in fluoride-treated animals. Toxicity was more prominent in 50 ppm of fluoride-treated animals. ConclusionFluoride showed potent neuronal toxicity as evidenced by alterations of various molecular markers.

Evaluation of (S)-T1 and (S)-T2 ligands targeting α3β4 nAChR as potential nicotine addiction pharmacotherapy.

Substance use disorders (SUDs) represent a significant global health concern, demanding the development of effective pharmacological treatments. To address this, an investigation was conducted to examine the anti-addictive properties of two compounds, (S)-T1 and (S)-T2, which specifically target the α3β4 nicotinic acetylcholine receptor (nAChR). The effects of (S)-T1 and (S)-T2 on nicotine-induced conditioned place preference (CPP), locomotor activity and dopamine levels in particular brain regions associated to addiction were investigated and compared in male C57BL/6N mice. The results demonstrate that neither (S)-T1 nor (S)-T2 induced place conditioning or conditioned place aversion (CPA), suggesting the absence of rewarding or aversive effects. Both compounds significantly attenuated nicotine-induced CPP, with (S)-T1 exhibiting a dose-dependent effect. Furthermore, the co-administration of (S)-T2 (10mg/kg) with nicotine markedly reduced locomotor activity compared to nicotine treatment alone. Additionally, dopamine analysis revealed that nicotine increased dopamine levels in the nucleus accumbens (NAc) and dorsal striatum, whereas the co-administration of (S)-T1 (1, 3, and 10mg/kg) and (S)-T2 (10mg/kg) significantly decreased dopamine levels in these brain regions. No significant effects were observed in the prefrontal cortex (PFC). These findings suggest that (S)-T1 and (S)-T2 hold promise for treating nicotine addiction by attenuating nicotine-induced CPP and modulating dopamine release in key reward-related brain regions. Further research is needed to gain insights into the underlying mechanisms behind their anti-addictive effects and substantiate their potential for treating nicotine addiction.

Daily rhythms in metabolic and locomotor behaviour of prematurely ageing PolgA mice.

Ageing is an inherent and intricate biological process that takes place in living organisms as time progresses. It involves the decline of multiple physiological functions, leading to body structure and overall performance modifications. The ageing process differs among individuals and is influenced by various factors, including lifestyle, environment and genetic makeup. Metabolic changes and reduced locomotor activity are common hallmarks of ageing. Our study focuses on exploring these phenomena in prematurely ageing PolgA(D257A/D257A) mice (also known as PolgA) aged 41-42 weeks, as they closely mimic human ageing. We assess parameters such as oxygen consumption (VO2), carbon dioxide production (VCO2), respiratory exchange ratio (RER) and locomotor activity using a metabolic cage for 4 days and comparing them with age-matched wild-type littermates (WT). Our findings revealed that VO2, VCO2, RER, locomotor activities, water intake and feeding behaviour show a daily rhythm, aligning with roughly a 24-h cycle. We observed that the RER was significantly increased in PolgA mice compared to WT mice during the night-time of the light-dark cycle, suggesting a shift towards a higher reliance on carbohydrate metabolism due to more food intake during the active phase. Additionally, female PolgA mice displayed a distinct phenotype with reduced walking speed, walking distance, body weight and grip strength in comparison to male PolgA and WT mice, indicating an early sign of ageing. Taken together, our research highlights the impact of sex-specific patterns on ageing traits in PolgA mice aged 41-42 weeks, which may be attributable to human ageing phenotypes. The unique genetic composition and accelerated ageing characteristics of PolgA mice make them invaluable in ageing studies, facilitating the investigation of underlying biological mechanisms and the identification of potential therapeutic targets for age-related diseases.

Exposure to the herbicide tebuthiuron affects behavior, enzymatic activity, morphology and physiology of the midgut of the stingless bee Partamona helleri

Partamona helleri is an important pollinator in the Neotropics. However, this bee faces an increased risk of pesticide exposure, potentially affecting both individual bees and entire colonies. Thus, this study aimed to evaluate the effects of the herbicide tebuthiuron on behavior, antioxidant activity, midgut morphology, and signaling pathways related to cell death, cell proliferation and differentiation in P. helleri workers. tebuthiuron significantly reduced locomotor activity and induced morphological changes in the midgut. The activity of the detoxification enzymes superoxide dismutase and glutathione S-transferase increased after exposure, indicating a detoxification mechanism. Furthermore, the herbicide led to alterations in the number of positive cells for signaling-pathway proteins in the midgut of bees, suggesting induction of apoptotic cell death and disruption of midgut epithelial regeneration. Therefore, tebuthiuron may negatively impact the behavior, antioxidant activity, morphology, and physiology of P. helleri workers, potentially posing a threat to the survival of this non-target organism.

Exposure Effects of Environmentally Relevant Concentrations of the Tricyclic Antidepressant Amitriptyline in Early Life Stage Zebrafish.

Antidepressants are one of the most globally prescribed classes of pharmaceuticals, and drug target conservation across phyla means that nontarget organisms may be at risk from the effects of exposure. Here, we address the knowledge gap for the effects of chronic exposure (28 days) to the tricyclic antidepressant amitriptyline (AMI) on fish, including for concentrations with environmental relevance, using zebrafish (Danio rerio) as our experimental model. AMI was found to bioconcentrate in zebrafish, was readily transformed to its major active metabolite nortriptyline, and induced a pharmacological effect (downregulation of the gene encoding the serotonin transporter; slc6a4a) at environmentally relevant concentrations (0.03 μg/L and above). Exposures to AMI at higher concentrations accelerated the hatch rate and reduced locomotor activity, the latter of which was abolished after a 14 day period of depuration. The lack of any response on the features of physiology and behavior we measured at concentrations found in the environment would indicate that AMI poses a relatively low level of risk to fish populations. The pseudopersistence and likely presence of multiple drugs acting via the same mechanism of action, however, together with a global trend for increased prescription rates, mean that this risk may be underestimated using current ecotoxicological assessment paradigms.

Effect of Cinnamaldehyde Chalcone on Behavior in Adult Zebrafish (Danio rerio): In Silico Approach.

The study focuses on the anxiolytic potential of chalcone (2E,4E)-1-(2-hydroxyphenyl)-5-phenylpenta-2,4-dien-1-one (CHALCNM) in adult zebrafish. Successfully synthesized in 58 % yield, CHALCNM demonstrated no toxicity after 96 h of exposure. In behavioral tests, CHALCNM (40 mg/kg) reduced locomotor activity and promoted less anxious behavior in zebrafish, confirmed by increased permanence in the light zone of the aquarium. Flumazenil reversed its anxiolytic effect, indicating interaction with GABAA receptors. Furthermore, CHALCNM (4 and 20 mg/kg) preserved zebrafish memory in inhibitory avoidance tests. Virtual screening and ADMET profile studies suggest high oral bioavailability, access to the CNS, favored by low topological polarity (TPSA≤75 Å2) and low incidence of hepatotoxicity, standing out as a promising pharmacological agent against the GABAergic system. In molecular coupling, CHALCNM demonstrated superior affinity to diazepam for the GABAA receptor. These results reinforce the therapeutic potential of CHALCNM in the treatment of anxiety, highlighting its possible future clinical application.

The Effect of Omega-3 Fatty Acid Supplementation and Exercise on Locomotor Activity, Exploratory Activity, and Anxiety-Like Behavior in Adult and Aged Rats.

Aging is an inevitable and complex biological process that is associated with a gradual decline in physiological functions and a higher disease susceptibility. Omega-3 fatty acids, particularly docosahexaenoic acid, play a crucial role in maintaining brain health and their deficiency is linked to age-related cognitive decline. Combining omega-3-rich diets with exercise may enhance cognitive function more effectively, as both share overlapping neurobiological and physiological effects. This study aimed to evaluate the effect of exercise and omega-3 fatty acid (FA) supplementation in two different doses (160 mg/kg and 320 mg/kg) on anxiety-like behavior and cognitive abilities in both adult and aged rats. Male Wistar rats (4-5- and 23-24-month-old) were randomly divided into seven groups: 3-week control supplemented with placebo without exercise, low-dose omega-3 FAs, high-dose omega-3 FAs, 7-week control supplemented with placebo without exercise, exercise-only, low-dose omega-3 FAs with exercise, and high-dose omega-3 FAs with exercise. The administered oil contained omega-3 FAs with DHA:EPA in a ratio of 1.5:1. Our results indicate that aging negatively impacts the locomotor and exploratory activity of rats. In adult rats, a low dose of omega-3 FAs reduces locomotor activity when combined with exercise while high dose of omega-3 FAs reduces anxiety-like behavior and improves recognition memory when combined with exercise. The combination of omega-3 FAs and exercise had varying impacts on behavior, suggesting a need for further research in this area to fully understand their therapeutic efficacy in the context of cognitive changes associated with aging.

Allosteric modulators of M1 muscarinic receptors enhance acetylcholine efficacy and decrease locomotor activity and turning behaviors in zebrafish

Allosteric modulation of muscarinic acetylcholine receptors (mAChR) has been identified as a potential strategy for regulating cholinergic signaling in the treatment of various neurological disorders. Most positive allosteric modulators (PAMs) of mAChR enhance agonist affinity and potency, while very few PAMs (e.g., amiodarone) selectively enhance G protein coupling efficacy. The key structural features of amiodarone responsible for enhancement of mAChR efficacy were examined in CHO cells expressing M1 receptors. Subsequent incorporation of these structural features into previously identified allosteric modulators of potency (i.e., n-benzyl isatins) generated ligands that demonstrated similar or better enhancement of mAChR efficacy, lower in vivo toxicity, and higher allosteric binding affinity relative to amiodarone. Notable ligands include 8a, c which respectively demonstrated the strongest binding affinity and the most robust enhancement of mAChR efficacy as calculated from an allosteric operational model. Amiodarone derivatives and hybrid ligands were additionally screened in wildtype zebrafish (Danio rerio) to provide preliminary in vivo toxicity data as well as to observe effects on locomotor and turning behaviors relative to other mAChR PAMs. Several compounds, including 8a, c, reduced locomotor activity and increased measures of turning behaviors in zebrafish, suggesting that allosteric modulation of muscarinic receptor efficacy might be useful in the treatment of repetitive behaviors associated with autism spectrum disorder (ASD) and other neuropsychiatric disorders.

Acute nicotine vapor normalizes sensorimotor gating and reduces locomotor activity deficits in HIV-1 transgenic rats.

Despite improved life expectancy of people with HIV (PWH), HIV-associated neurocognitive impairment (NCI) persists, alongside deficits in sensorimotor gating and neuroinflammation. PWH exhibit high smoking rates, possibly due to neuroprotective, anti-inflammatory, and cognitive-enhancing effects of nicotine, suggesting potential self-medication. Here, we tested the effects of acute nicotine vapor exposure on translatable measures of sensorimotor gating and exploratory behavior in the HIV-1 transgenic (HIV-1Tg) rat model of HIV. Male and female HIV-1Tg and F344 control rats (n=57) were exposed to acute nicotine or vehicle vapor. Sensorimotor gating was assessed using prepulse inhibition (PPI) of the acoustic startle response, and exploratory behavior was evaluated using the behavioral pattern monitor (BPM). Vehicle-treated HIV-1Tg rats exhibited PPI deficits at low prepulse intensities compared to F344 controls, as seen previously. No PPI deficits were observed in nicotine-treated HIV1-Tg rats, however. HIV-1Tg rats were hypoactive in the BPM relative to controls, whilst nicotine vapor increased activity and exploratory behavior across genotypes. Cotinine analyses confirmed comparable levels of the primary metabolite of nicotine across genotypes. Previous findings of PPI deficits in HIV-1Tg rats were replicated and, importantly, attenuated by acute nicotine vapor. Evidence for similar cotinine levels suggest a nicotine-specific effect in HIV-1Tg rats. HIV-1Tg rats had reduced exploratory behavior compared to controls, attenuated by acute nicotine vapor. Therefore, acute nicotine may be beneficial for remediating sensorimotor and locomotor activity deficits in PWH. Future studies should determine the long-term effects of nicotine vapor on similar HIV/NCI-relevant behaviors.

A plant-derived δ opioid receptor agonist rubiscolin-6 ameliorates sickness behavior in mice with cancer cachexia

Cancer cachexia, which encompasses a range of sickness behaviors such as anorexia, reduced locomotor activity, and depression, diminishes quality of life and increases mortality in cancer patients. Rubiscolin-6 is a hexapeptide derived from ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), a major plant leaf protein. Previous reports have demonstrated that rubiscolin-6 functions as an agonist of the δ opioid receptor, inducing diverse effects such as orexigenic, antinociceptive, and antidepressant-like effects. In this study, we investigated the effects of rubiscolin-6 on sickness behavior in colon26-bearing cachexia model mice. Intraperitoneal administration of rubiscolin-6 enhanced food intake in cachexic mice with chronic anorexia. It also increased locomotor activity, which decreased in cachexic mice, as assessed by the open field test. Moreover, the tail suspension test revealed that rubiscolin-6 alleviated depression-like behavior in mice with cachexia. These findings imply that rubiscolin-6 could be used to ameliorate the sickness behavior associated with cancer cachexia.

The effect of graphene oxide administration on the brains of male mice: Behavioral study and assessment of oxidative stress

Graphene oxide (GO) nanoparticles are attracting growing interest in various fields, not least because of their distinct characteristics and possible uses. However, concerns about their impact on neurological health are emerging, underlining the need for in-depth studies to assess their neurotoxicity. This study examines GO exposure's neurobehavioral and biochemical effects on the central nervous system (CNS). To this end, we administered two doses of GO (2 and 5 mg/kg GO) to mice over a 46-day treatment period. We performed a battery of behavioral tests on the mice, including the open field to assess locomotor activity, the maze plus to measure anxiety, the pole test to assess balance and the rotarod to measure motor coordination. In parallel, we analyzed malondialdehyde (MDA) levels and catalase activity in the brains of mice exposed to GO nanoparticles. In addition, X-ray energy dispersive (EDX) analysis was performed to determine the molecular composition of the brain. Our observations reveal brain alterations in mice exposed to GO by intraperitoneal injection, demonstrating a dose-dependent relationship. We identified behavioral alterations in mice exposed to GO, such as increased anxiety, decreased motor coordination, reduced locomotor activity and balance disorders. These changes were dose-dependent, suggesting a correlation between the amount of GO administered and the extent of behavioral alterations. At the same time, a dose-dependent increase in malondialdehyde and catalase activity was observed, reinforcing the correlation between exposure intensity and associated biochemical responses.

Maternal alcohol drinking patterns predict offspring neurobehavioral outcomes

The timing, rate, and quantity of gestational alcohol consumption, collectively referred to here as Maternal Drinking Patterns (MDPs), are of known importance to fetal developmental outcomes. However, few studies have directly evaluated the impact of MDPs on offspring behavior. To do so, we used specialized equipment to record the precise amount and timing of alcohol consumption in pregnant dams, and then characterized MDPs using Principle Component Analysis (PCA). We next tested offspring on behaviors we have previously identified as impacted by prenatal alcohol exposure, and evaluated them where possible in the context of MDPs. Male alcohol exposed mice exhibited longer latencies to fall on the rotarod compared to their controls, which we attribute to a delayed decrease in body weight-gain. This effect was mediated by MDPs within the first 15 min of alcohol access (i.e. alcohol frontloading), where the highest performing male offspring came from dams exhibiting the highest rate of alcohol frontloading. Female alcohol exposed mice displayed reduced locomotor activity in the open field compared to controls, which was mediated by MDPs encompassing the entire drinking session. Surprisingly, total gestational alcohol exposure alone was not associated with any behavioral outcomes. Finally, we observed allodynia in alcohol exposed mice that developed more quickly in males compared to females, and which was not observed in controls. To our knowledge, this report represents the highest resolution assessment of alcohol drinking throughout gestation in mice, and one of few to have identified relationships between specific alcohol MDPs and neurobehavioral outcomes in offspring.

Zebrafish as a Human Muscle Model for Studying Age-Dependent Sarcopenia and Frailty.

Currently, there is an increase in the aging of the population, which represents a risk factor for many diseases, including sarcopenia. Sarcopenia involves progressive loss of mass, strength, and function of the skeletal muscle. Some mechanisms include alterations in muscle structure, reduced regenerative capacity, oxidative stress, mitochondrial dysfunction, and inflammation. The zebrafish has emerged as a new model for studying skeletal muscle aging because of its numerous advantages, including histological and molecular similarity to human skeletal muscle. In this study, we used fish of 2, 10, 30, and 60 months of age. The older fish showed a higher frailty index with a value of 0.250 ± 0.000 because of reduced locomotor activity and alterations in biometric measurements. We observed changes in muscle structure with a decreased number of myocytes (0.031 myocytes/μm2 ± 0.004 at 60 months) and an increase in collagen with aging up to 15% ± 1.639 in the 60-month group, corresponding to alterations in the synthesis, degradation, and differentiation pathways. These changes were accompanied by mitochondrial alterations, such as a nearly 50% reduction in the number of intermyofibrillar mitochondria, 100% mitochondrial damage, and reduced mitochondrial dynamics. Overall, we demonstrated a similarity in the aging processes of muscle aging between zebrafish and mammals.