Early deprivation increases high-leaning behavior, a novel anxiety-like behavior, in the open field test in rats

Nicotinamide adenine dinucleotide treatment confers resistance to neonatal ischemia and hypoxia: effects on neurobehavioral phenotypes

JOURNAL/nrgr/04.03/01300535-202412000-00031/figure1/v/2024-04-08T165401Z/r/image-tiff Neonatal hypoxic-ischemic brain injury is the main cause of hypoxic-ischemic encephalopathy and cerebral palsy. Currently, there are few effective clinical treatments for neonatal hypoxic-ischemic brain injury. Here, we investigated the neuroprotective and molecular mechanisms of exogenous nicotinamide adenine dinucleotide, which can protect against hypoxic injury in adulthood, in a mouse model of neonatal hypoxic-ischemic brain injury. In this study, nicotinamide adenine dinucleotide (5 mg/kg) was intraperitoneally administered 30 minutes before surgery and every 24 hours thereafter. The results showed that nicotinamide adenine dinucleotide treatment improved body weight, brain structure, adenosine triphosphate levels, oxidative damage, neurobehavioral test outcomes, and seizure threshold in experimental mice. Tandem mass tag proteomics revealed that numerous proteins were altered after nicotinamide adenine dinucleotide treatment in hypoxic-ischemic brain injury mice. Parallel reaction monitoring and western blotting confirmed changes in the expression levels of proteins including serine (or cysteine) peptidase inhibitor, clade A, member 3N, fibronectin 1, 5'-nucleotidase, cytosolic IA, microtubule associated protein 2, and complexin 2. Proteomics analyses showed that nicotinamide adenine dinucleotide ameliorated hypoxic-ischemic injury through inflammation-related signaling pathways (e.g., nuclear factor-kappa B, mitogen-activated protein kinase, and phosphatidylinositol 3 kinase/protein kinase B). These findings suggest that nicotinamide adenine dinucleotide treatment can improve neurobehavioral phenotypes in hypoxic-ischemic brain injury mice through inflammation-related pathways.

Effects of early-life stress followed by access to stevia or sucralose during adolescence on weight gain, glycemia, and anxiety-related behaviors in male and female rats

Early-life stress and subsequent high-calorie diets during adolescence are known to be risk factors for developing metabolic and psychological disorders. Although non-nutritive sweeteners such as stevia and sucralose have been a useful alternative to reduce sugar consumption, the effects of prolonged consumption of these sweeteners on metabolism and behavior in adolescents remain unclear. Here, we evaluated the effects of early-stress followed by access to stevia or sucralose during adolescence on weight gain, glycemia, and anxiety-related behaviors in male and female rats. During postnatal days (PNDs) 1-21, pups were separated twice a day, for 180 min each time, from their dam nest while non-separated pups served as controls. The pups were weaned, separated by sex and randomly distributed into the stevia, sucralose and water conditions. During PNDs 26-50, two bottles containing water and stevia or sucralose were placed in the animal home-cages, and body weight and blood glucose measures were scored. On PNDs 50 and 51, behavioral measures were obtained in the open-field test. Results showed that male rats consuming stevia reduced body weight gain, blood glucose and increased locomotion. Early-stress led to low blood glucose and alterations in anxiety and locomotion-related behaviors in a sex-dependent manner. Moreover, sucralose access during adolescence reversed the effects of early-stress on anxiety-related behaviors in female rats. The results suggest that the consumption of stevia and sucralose could be an alternative for the replacement of sugar-sweetened beverages, especially in adolescents who have had adverse early-life experiences.

Effect of a probiotic fermented milk supplementation on behavior and sleep

This study attempted to analyze the effect of supplementing Wistar-Kyoto rats with fermented milk containing the probiotic Bifidobacterium animalis BB-12 and pomegranate juice on the microbiota-gut-brain axis of rats, with special focus on their behavior, sleep patterns, and response to stress. This study was divided into two experiments: (1) For the behavioral analysis the animals were divided into two groups: Fermented probiotic milk (BB + 1) and control (BB-). (2) For the sleep analysis the animals were divided into two groups: Fermented probiotic milk (BB + 2) and control (H2O). For the behavioral analysis, the open field method was used, which evaluates the behavior after ten, twenty, and thirty days of supplementation. For sleep analysis, the animals were submitted to implantation of electrodes and 24 h polysomnography, followed by 48 h sleep deprivation (REM) and 48 h polysomnography, then euthanized 100 days after the beginning of the experiment. In addition, animal feces were collected before and after sleep deprivation to assess its effects on the microbiota. A decrease in anxiety-related behaviors was observed in the supplemented animals and an increase in sleep efficiency and a reduction in the number of awakenings of the animals before deprivation. It has also been observed that sleep deprivation decreased the amount of total bacterial DNA. The number of copies of genomes of the genus Bifidobacterium did not differ in both groups.

The potential beneficial effects of Lactobacillus plantarum GM11 on rats with chronic unpredictable mild stress- induced depression

OBJECTIVE

The main purpose of the present study was to assess the beneficial effect of Lactobacillus plantarum GM11 (LacP GM11), screened from Sichuan traditional fermented food, in depressive rats induced by chronic unpredictable mild stress (CUMS).

METHODS

Male SPF SD rats were randomly assigned to 3 groups: the control group, CUMS group and CUMS + LacP GM11 group (n = 10). The rats in the CUMS and LacP GM11 groups received CUMS stimulation for 42 d. The behavioral tests and levels of monoamine neurotransmitter, glucocorticoid hormone and brain-derived neurotrophic factor (BDNF) in the serum and hippocampus were measured. The effects of LacP GM11 on the mRNA and protein expression of BDNF and cAMP response element binding protein (CREB) in the hippocampus were also investigated.

RESULTS

After supplementation for 21 d, LacP GM11 was associated with alleviation of depressive-like behavior, not anxiety-like behavior, in depressive rats. LacP GM11 increased the levels of 5-hydroxytryptamine (5-HT) and BDNF and decreased the level of cortisol (CORT) in the serum and hippocampus in depressed rats. In addition, treatment with LacP GM11 also increased the mRNA and protein expression of BDNF and CREB in the hippocampus.

CONCLUSIONS

This work has revealed that LacP GM11 has potential beneficial effects on depression. This effect might be related to alleviating monoamine neurotransmitter deficiency, HPA axis hyperfunction and CREB-BDNF signaling pathway downregulation. This study demonstrates that LacP GM11 could be a potential therapeutic approach to treat depression and other mental health problems.

Particulate matter (PM10) exacerbates on MK-801-induced schizophrenia-like behaviors through the inhibition of ERK-CREB-BDNF signaling pathway

Particulate matter (PM), released into the air by a variety of natural and human activities, is a key indicator of air pollution. Although PM is known as the extensive health hazard to affect a variety of illness, few studies have specifically investigated the effects of PM10 exposure on schizophrenic development. In the present study, we aimed to investigate the impact of PM10 on MK-801, N-methyl-D-aspartate (NMDA) receptor antagonist, induced schizophrenia-like behaviors in C57BL/6 mouse. Preadolescent mice were exposed PM10 to 3.2 mg/m3 concentration for 4 h/day for 2 weeks through a compartmentalized whole-body inhalation chamber. After PM10 exposure, we conducted behavioral tests during adolescence and adulthood to investigate longitudinal development of schizophrenia. We found that PM10 exacerbated schizophrenia-like behavior, such as psychomotor agitation, social interaction deficits and cognitive deficits at adulthood in MK-801-induced schizophrenia animal model. Furthermore, the reduced expression levels of brain-derived neurotrophic factor (BDNF) and the phosphorylation of BDNF related signaling molecules, extracellular signal-regulated kinase (ERK) and cAMP response element-binding protein (CREB), were exacerbated by PM10 exposure in the adult hippocampus of MK-801-treated mice. Thus, our present study demonstrates that exposure to PM10 in preadolescence exacerbates the cognitive impairment in animal model of schizophrenia, which are considered to be facilitated by the decreased level of BDNF through reduced ERK-CREB expression.

Strongly Adhesive, Self-Healing, Hemostatic Hydrogel for the Repair of Traumatic Brain Injury

With wide clinical demands, therapies for traumatic brain injury (TBI) are a major problem in surgical procedures and after major trauma. Due to the difficulty in regeneration of neurons or axons after injury, as well as the inhibition of blood vessel growth by the formation of neural scars, existing treatment measures have limited effectiveness in repairing brain tissue. Herein, the biomultifunctional hydrogels are developed for TBI treatment based on the Schiff base reaction of calcium ion (Ca2+)-cross-linked oxidized sodium alginate (OSA) and carboxymethyl chitosan (CMCS). The obtained COCS hydrogel exhibits excellent adhesion to wet tissues, self-repair capability, and antimicrobial properties. What's particularly interesting is that the addition of Ca2+ increases the hydrogel's extensibility, enhancing its hemostatic capabilities. Biological assessments indicate that the COCS hydrogel demonstrates excellent biocompatibility, hemostatic properties, and the ability to promote arterial vessel repair. Importantly, the COCS hydrogel promotes the growth of cerebral microvessels by upregulating CD31, accelerates the proliferation of astrocytes, enhances the expression of GFAP, and stimulates the expression of neuron-specific markers such as NEUN and β-tubulin. All of these findings highlight that the strongly adhesive, self-healing, hemostatic hydrogel shows great potential for the repair of traumatic brain injury and other tissue repair therapy.

Early-life exposure to PM2.5 leads to ASD-like phenotype in male offspring rats through activation of PI3K-AKT signaling pathway

Previous studies have shown that early-life exposure to fine particulate matter (PM2.5) is associated with an increasing risk of autism spectrum disorder (ASD), however, the specific sensitive period of ASD is unknown. Here, a model of dynamic whole-body concentrated PM2.5 exposure in pre- and early-postnatal male offspring rats (MORs) was established. And we found that early postnatal PM2.5 exposed rats showed more typical ASD behavioral characteristics than maternal pregnancy exposure rats, including poor social interaction, novelty avoidance and anxiety disorder. And more severe oxidative stress and inflammatory responses were observed in early postnatal PM2.5 exposed rats. Moreover, the expression level of phosphatase and tensin homolog deleted on chromosome ten (PTEN) was down-regulated and the ratios of p-PI3K/PI3K and p-AKT/AKT were up-regulated in early postnatal PM2.5 exposed rats. This study suggests that early postnatal exposure to PM2.5 is more susceptible to ASD-like phenotype in offspring than maternal pregnancy exposure and the activation of PI3K-AKT signaling pathway may represent underlying mechanisms.

Cynaroside improved depressive-like behavior in CUMS mice by suppressing microglial inflammation and ferroptosis

Depression is a common mental health disorder, and in recent years, the incidence of various forms of depression has been on the rise. Most medications for depression are highly dependency-inducing and can lead to relapse upon discontinuation. Therefore, novel treatment modalities and therapeutic targets are urgently required. Traditional Chinese medicine (TCM) offers advantages in the treatment of depression owing to its multi-target, multi-dimensional approach that addresses the root cause of depression by regulating organ functions and balancing Yin and Yang, with minimal side effects. Cynaroside (CNS), an extract from the traditional Chinese herb honeysuckle, is a flavonoid compound with antioxidant properties. In this study, network pharmacology identified 44 potential targets of CNS associated with depression and several highly correlated inflammatory signaling pathways. CNS alleviated LPS-induced M1 polarization and the release of inflammatory factors in BV-2 cells. Transcriptomic analysis and validation revealed that CNS reduced inflammatory polarization, lipid peroxidation, and ferroptosis via the IRF1/SLC7A11/GPX4 signaling pathway. In vivo experiments showed that CNS treatment had effects similar to those of fluoxetine (FLX). It effectively ameliorated anxiety-, despair-, and anhedonia-like states in chronic unpredictable mild stress (CUMS)-induced mice and reduced microglial activation in the hippocampus. Thus, we conclude that CNS exerts its therapeutic effect on depression by inhibiting microglial cells from polarizing into the M1 phenotype and reducing inflammation and ferroptosis levels. This study provides further evidence that CNS is a potential antidepressant, offering new avenues for the treatment of depression.

Resveratrol Improves Cognitive Function in Post-stroke Depression Rats by Repressing Inflammatory Reactions and Oxidative Stress via the Nrf2/HO-1 Pathway

Post-stroke depression (PSD) is a prevalent mental health issue, and resveratrol (RES) has been implicated in its management. This study aimed to elucidate the impact of RES on PSD. A PSD rat model was established through middle cerebral artery occlusion and chronic unpredictable mild stress. Rats received RES via gavage, and depressive behaviors were evaluated through various measures. Cerebral infarction areas and brain tissue pathology were assessed using TTC and H&E staining. Levels of inflammatory factors (TNF-α/IL-1β/IL-6/IL-10), neurotransmitters (ACH/DA/5-HT/BDNF), and oxidative stress-related indicators (SOD/GSH-Px/MDA), along with the total Nrf2/C-Nrf2/N-Nrf2/HO-1 proteins, were analyzed. The role of the Nrf2/HO-1 pathway was investigated by co-treating rats with RES and either an Nrf2 pathway specific inhibitor (ML385) or activator (dimethyl fumarate). PSD rats exhibited depressive behaviors, disrupted neurotransmitter levels, and oxidative stress markers. RES treatment effectively alleviated these symptoms and activated the Nrf2/HO-1 pathway in PSD rat brain tissues. Co-administration of ML385 attenuated the beneficial effects of RES in PSD rats. Altogether, RES mitigates depressive behaviors, improves cognitive dysfunction, and reduces oxidative stress and inflammatory response in PSD rats. These effects are mediated through the activation of the Nrf2/HO-1 pathway, suggesting RES as a potential therapeutic agent for PSD-related cognitive impairment.

Validation of Wistar-Kyoto rats kept in solitary housing as an animal model for depression using voxel-based morphometry

Major depressive disorder is a common psychiatric condition often resistant to medication. The Wistar-Kyoto (WKY) rat has been suggested as an animal model of depression; however, it is still challenging to translate results from animal models into humans. Solitary housing is a mild stress paradigm that can simulate the environment of depressive patients with limited social activity due to symptoms. We used voxel-based morphometry to associate the solitary-housed WKY (sWKY) rat model with data from previous human studies and validated our results with behavioural studies. As a result, atrophy in sWKY rats was detected in the ventral hippocampus, caudate putamen, lateral septum, cerebellar vermis, and cerebellar nuclei (p < 0.05, corrected for family-wise error rate). Locomotor behaviour was negatively correlated with habenula volume and positively correlated with atrophy of the cerebellar vermis. In addition, sWKY rats showed depletion of sucrose consumption not after reward habituation but without reward habituation. Although the application of sWKY rats in a study of anhedonia might be limited, we observed some similarities between the regions of brain atrophy in sWKY rats and humans with depression, supporting the translation of sWKY rat studies to humans.

Regulatory Effects and Mechanisms of L-Theanine on Neurotransmitters via Liver-Brain Axis Under a High Protein Diet

Excessive protein intake causes liver and brain damage and neurotransmitter disorders, thereby inducing cognitive dysfunction. L-theanine can regulate the neurotransmitter content and show great potential in liver and brain protection. However, it remains unclear whether l-theanine effectively regulates neurotransmitter content under high-protein diet. A 40-day feeding experiment was performed in Sprague Dawley rats to investigate the regulatory effects and mechanisms of l-theanine on neurotransmitters via liver-brain axis in high-protein diets. The results showed that a 30% protein diet increased the liver and brain neurotransmitter content while maintaining the normal structure of liver and the hippocampal CA1 of brain and improving the autonomous behavior of rats. In contrast, 40% and 50% protein diets decreased the content of neurotransmitters, affected autonomous behavior, destroyed the hippocampal CA1 of brain structure, increased hepatic inflammatory infiltration, lipid degeneration, and hepatocyte eosinophilic change in liver, increased liver AST, ALT, MDA, CRP, and blood ammonia level, and decreased liver SOD and CAT level. However, l-theanine improved liver and brain neurotransmitter content, autonomous behavior, liver and hippocampal brain structure, and liver biochemical indicators in 40% and 50% protein diets. To explore how LTA can eliminate the adverse effects of a high-protein diet, we analyzed different metabolites and proteomes and using western blotting for validate quantitatively. We found that l-theanine regulates the activity of PF4 and G protein subunit alpha i2, increases the content of brain-derived neurotrophic factor and dopamine under a 20% protein diet. In addition, l-theanine can activate the adenylate cyclase-protein kinase A pathway through the protein alpha/beta-hydrolase domain protein 12 to regulate the content of neurotransmitters under a 40% protein diet, thereby exerting a neuroprotective effect.

Effects of aqueous extracts and volatile oils prepared from Huaxiang Anshen decoction on p-chlorophenylalanine-induced insomnia mice

ETHNOPHARMACOLOGICAL RELEVANCE

Insomnia occurs frequently in modern society, and its common symptoms include difficulty in falling asleep and decreased sleep quality and time, memory, and attention. With the advantages of having few side-effects and reduced drug-dependence, a compound traditional Chinese medicine (TCM) prescription called Huaxiang Anshen Decoction (HAD) has been widely used in clinical practice in China mainly for primary insomnia treatment. Although the effects of volatile oils from TCM herbs have been increasingly reported, volatile oils in HAD are conventionally neglected because of its preparation process and clinical usage. Therefore, exploring the anti-insomnia effects of volatile oils from HAD is of great importance.

AIM OF THE STUDY

The sedative and hypnotic effects of the conventional aqueous extracts, the volatile oils from HAD, and their combinations were investigated.

METHODS

The main components in HAD volatile oils (HAD-Oils), were analyzed through gas chromatography-mass spectrometry (GC-MS). The HAD volatile oil inclusion complex (HAD-OIC) was prepared with β-cyclodextrin, and characterized. P-chlorophenylalanine (PCPA) was used to induce insomnia mice model and the test groups of HAD aqueous extract (HAD-AE), HAD-OIC and their combination (AE-OIC). An open field test was used in evaluating the mice's activities, and the levels of 5-hydroxytryptamine (5-HT) in mice sera, glutamate (Glu) in the hypothalamus, and γ-aminobutyric acid (γ-GABA) and dopamine (DA) in the brain tissues were assayed by enzyme-linked immunosorbent assay (ELISA).

RESULTS

A total 74 components in HAD-Oil were determined by GC/MS, and cyperenone (20.46%) and α-cyperone (10.39%) had the highest relative content. The characterization results of the physical phase showed that volatile oils were successfully encapsulated by β-cyclodextrin and HAD-OIC was produced. The average encapsulation rates of cyperenone and α-cyperone were 79.93% and 71.96%, respectively. The results of pharmacology study showed that all the test groups increased the body weight and decreased voluntary activity when compared with the model group (P < 0.05). The HAD-AE, HAD-OIC, and AE-OIC groups increased the levels of 5-HT in the sera and DA and Glu/γ-GABA in the brains, and AE-OIC groups showed better performance than the other test groups.

CONCLUSIONS

HAD-Oil exerts sedative and hypnotic effects, which are increased when it is used with HAD-AEs. This result provides a favorable experimental evidence that volatile oils should be retained for the further development of HAD.

Discovery and validation of genes driving drug-intake and related behavioral traits in mice

Substance use disorders are heritable disorders characterized by compulsive drug use, the biological mechanisms for which remain largely unknown. Genetic correlations reveal that predisposing drug-naïve phenotypes, including anxiety, depression, novelty preference and sensation seeking, are predictive of drug-use phenotypes, thereby implicating shared genetic mechanisms. High-throughput behavioral screening in knockout (KO) mice allows efficient discovery of the function of genes. We used this strategy in two rounds of candidate prioritization in which we identified 33 drug-use candidate genes based upon predisposing drug-naïve phenotypes and ultimately validated the perturbation of 22 genes as causal drivers of substance intake. We selected 19/221 KO strains (8.5%) that had a difference from control on at least one drug-naïve predictive behavioral phenotype and determined that 15/19 (~80%) affected the consumption or preference for alcohol, methamphetamine or both. No mutant exhibited a difference in nicotine consumption or preference which was possibly confounded with saccharin. In the second round of prioritization, we employed a multivariate approach to identify outliers and performed validation using methamphetamine two-bottle choice and ethanol drinking-in-the-dark protocols. We identified 15/401 KO strains (3.7%, which included one gene from the first cohort) that differed most from controls for the predisposing phenotypes. 8 of 15 gene deletions (53%) affected intake or preference for alcohol, methamphetamine or both. Using multivariate and bioinformatic analyses, we observed multiple relations between predisposing behaviors and drug intake, revealing many distinct biobehavioral processes underlying these relationships. The set of mouse models identified in this study can be used to characterize these addiction-related processes further.

Treatment of polycystic ovary syndrome and its associated psychiatric symptoms with the Mongolian medicine Nuangong Qiwei Pill and macelignan

ETHNOPHARMACOLOGICAL RELEVANCE

The Mongolian medicine Nuangong Qiwei Pill (NGQW) is a folk prescription with a long history of use by the Mongolian people. NGQW comprises seven Mongolian medicines, which have the effects of regulating and nourishing blood, warming the uterus, dispelling cold and relieving pain. For a long time, it has been used as a good remedy for gynecological diseases, with remarkable curative effects, favored by the majority of patients and recommended by doctors. Polycystic ovary syndrome (PCOS) is a common gynecological endocrine disorder that can lead to menstrual disorders or infertility. In the gynecological classification of Mongolian medicine, polycystic ovary syndrome has not been distinguished in detail, and the mechanism of NGQW in the treatment of polycystic ovary syndrome has not been scientifically studied and standardized.

AIM OF THE STUDY

The aim of this study was to clarify the mechanism of action of NGQW and macelignan in the treatment of PCOS and to provide a reference for the clinical application of these drugs.

MATERIALS AND METHODS

The effect of intragastric administration of NGQW and macelignan on PCOS model mice was observed. The mental status of mice was examined behaviorally, and serum hormone levels and oxidative stress parameters were measured by ELISA. Giemsa staining was used to detect the reproductive cycle, and HE staining was used to observe the ovarian status. Immunofluorescence staining was performed to observe the proliferation and apoptosis of ovarian granulosa cells. qRT‒PCR was conducted to measure the expression of IL-6, BAX, BCL-2, and estrogen synthesis-related genes in ovarian tissue and particle cells.

RESULTS

In the dehydroepiandrosterone (DHEA)-induced PCOS model mice, both NGQW and macelignan improved the estrous cycle; increased the estradiol (E2) content; lowered testosterone (T), progesterone (P) and luteinizing hormone (LH) levels; reduced the number of polycystic follicles; promoted granulosa cell proliferation; reduced granulosa cell apoptosis; and alleviated depression and anxiety. In addition, Nuangong Qiwei Pill and macelignan reduced the mRNA levels of the ovarian inflammatory factor IL-6; improved the disordered levels of the antioxidant indicators GSH, MDA, and SOD; and activated the TGF-β3 signaling pathway to increase the transcription of Cyp19a1, which increases estrogen secretion.

CONCLUSION

NGQW and macelignan can treat PCOS through the TGF-β3/Smad/Cyp19a1 signaling pathway to regulate the secretion ability of ovarian granulosa cells. Our research justifies the traditional use of NGQW to treat PCOS and enriches the scope of action of macelignan.

Integrating serum metabolomics and network analysis to explore the antidepressant activity of crocin in rats with chronic unexpected mild stress-induced depression

CONTEXT

Crocin exhibits anti-depressant properties. However, its underlying mechanisms and its relationship with metabolomics remain unclear.

OBJECTIVE

This study elucidates the mechanism of action and potential targets of crocin in treating chronic unexpected mild stress (CUMS)-induced depression in rats.

MATERIALS AND METHODS

Male Sprague-Dawley (SD) rats underwent 4 weeks of CUMS to establish the depression model. The normal control (distilled water), crocin (25 mg/kg), and fluoxetine (5.4 mg/kg) groups were orally administered for 4-weeks. Behavioural tests evaluated the effects of crocin, while liquid chromatography-mass spectrometry metabolomics identified differential metabolites and their associated metabolic pathways. Subsequently, network pharmacology was utilized to predict the targets of crocin.

RESULTS

Crocin significantly increased body weight (from 319.16 ± 4.84 g to 325.67 ± 2.84 g), sucrose preference (from 0.46 ± 0.09 to 0.70 ± 0.09), vertical activity (from 2.83 ± 1.94 to 8 ± 2.36), horizontal activity (from 1 ± 0.63 to 4.5 ± 3.08) and decreased immobilization time (from 13.16 ± 2.69 to 3.97 ± 3.00). Metabolomics analysis identified 7 metabolites and 5 associated metabolic pathways. From the combined analysis of network pharmacology and metabolomics, three targets (PRMT1, CYP3A4, and GLB1) are the overlapping targets and the two most important metabolic pathways are tryptophan metabolism and glycerolipid metabolism.

DISCUSSION AND CONCLUSIONS

This study provides insights into the antidepressant therapeutic effect of crocin and its underlying mechanisms. The findings contribute to a better understanding of the metabolic mechanism involved in the anti-depressant effect of crocin, establishing a strong foundation for future research in this area.

Role of Imaging Modalities and N-Acetylcysteine Treatment in Sepsis-Associated Encephalopathy

Sepsis-associated encephalopathy is a severe systemic infection complication. Although early stages involve pathophysiological changes, detection using conventional imaging is challenging. Glutamate chemical exchange saturation transfer and diffusion kurtosis imaging can noninvasively investigate cellular and molecular events in early disease stages using magnetic resonance imaging (MRI). N-Acetylcysteine, an antioxidant and precursor of glutathione, regulates neurotransmitter glutamate metabolism and participates in neuroinflammation. We investigated the protective role of n-acetylcysteine in sepsis-associated encephalopathy using a rat model and monitored changes in brain using magnetic resonance (MR) molecular imaging. Bacterial lipopolysaccharide was injected intraperitoneally to induce a sepsis-associated encephalopathy model. Behavioral performance was assessed using the open-field test. Tumor necrosis factor α and glutathione levels were detected biochemically. Imaging was performed using a 7.0-T MRI scanner. Protein expression, cellular damage, and changes in blood-brain barrier permeability were assessed using western blotting, pathological staining, and Evans blue staining, respectively. Lipopolysaccharide-induced rats showed reduced anxiety and depression after treatment with n-acetylcysteine. MR molecular imaging can identify pathological processes at different disease stages. Furthermore, rats treated with n-acetylcysteine showed increased glutathione levels and decreased tumor necrosis factor α, suggesting enhanced antioxidant capacity and inhibition of inflammatory processes, respectively. Western blot analysis showed reduced expression of nuclear factor kappa B (p50) protein after treatment, suggesting that n-acetylcysteine inhibits inflammation via this signaling pathway. Finally, n-acetylcysteine-treated rats showed reduced cellular damage by pathology and reduced extravasation of their blood-brain barrier by Evans Blue staining. Thus, n-acetylcysteine might be a therapeutic option for sepsis-associated encephalopathy and other neuroinflammatory diseases. Furthermore, noninvasive "dynamic visual monitoring" of physiological and pathological changes related to sepsis-associated encephalopathy was achieved using MR molecular imaging for the first time, providing a more sensitive imaging basis for early diagnosis, identification, and prognosis.

Rosinidin inhibits NF-κB/ Nrf2/caspase-3 expression and restores neurotransmitter levels in rotenone-activated Parkinson's disease

Objectives

The examination was sighted to study the preventive effects of rosinidin against rotenone-activated Parkinson's disease in rats.

Methods

Animals were randamoized into five groups: I-saline, II-rotenone (0.5 mg/kg/b.wt.), III- IV-10 and 20 mg/kg rosinidin after rotenone and V-20 mg/kg rosinidin per se for 28 days and were assigned for behavioral analysis., Biochemical parameters i.e. lipid peroxidation, endogenous antioxidants, nitrite level, neurotransmitter levels, proinflammatory biomarkers such as interleukin- 6 (IL-6), tumor necrosis factor-α, IL-1β, nuclear factor kappa B, nuclear factor erythroid 2-related factor 2, and caspase-3 were assessed on the 29th day of the research.

Results

Rosinidin augmented the effectiveness of rotenone on akinesia, catalepsy, forced-swim test, rotarod, and open-field test. Biochemical findings indicated that treatment of rosinidin showed restoring neuroinflammatory cytokines, antioxidants, and neurotransmitter levels in rotenone-injected rats.

Conclusion

As a result of rosinidin treatment, the brain was protected from oxidative stress-induced neuronal damage and inhibited neuroinflammatory cytokines.

Modified Erchen decoction ameliorates cognitive dysfunction in vascular dementia rats via inhibiting JAK2/STAT3 and JNK/BAX signaling pathways

BACKGROUND

Vascular dementia (VaD) is one of the most common clinical syndromes of progressive neurocognitive dysfunction with uncertain mechanisms. Modified Erchen decoction (MECD), developed from "Erchen decoction (ECD)" recorded in "Taiping Huimin Heji Jufang", showed a good effect in the treatment of VaD. However, its therapeutic mechanism is still unclear.

PURPOSE

This study aimed to elucidate the multi-target mechanisms of MECD against VaD in vivo and in vitro.

METHODS

VaD model was established by two-vessel obstruction (2-VO) in Sprague-Dawley rats. Six groups, including the control, 2-VO operation, MECD treatment (2.5, 5.0 and 10.0 g kg^-1 d^-1), donepezil hydrochloride (positive control, 0.45 g kg^-1 d^-1) were designed in the whole experiment. After oral administration for 4 weeks, the effects of MECD were verified by behavioral experiments, histological observation, and biochemical index analysis. The chemical profiling of MECD was performed by UHPLC-Orbitrap Fusion-HRMS, and a "compound-target-pathway" multivariate network was constructed to validate and elucidate its pharmacological mechanisms.

RESULTS

Compared with 2-VO group, MECD treatment significantly alleviated anxiety and improved spatial memory in VaD rats according to the open field test (OFT) and Y-maze test. A significant increase in neuron number was observed from hematoxylin and eosin (H&E) stained images in cornu ammonis 1 (CA1) of the hippocampal region after MECD treatment. On the one hand, MECD reduced the plasma levels of triglyceride (TG), low-density lipoprotein (LDL), malondialdehyde (MDA), and amyloid-beta 42 (Aβ42), and inhibited mRNA expression of interleukin-1 beta (Il-1β) and Il-6 in the hippocampus. On the other hand, superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) were significantly increased after treatment with MECD. Moreover, MECD reduced the mRNA expression and protein expression of janus kinase 2 (JAK2), signal transducer and activator of transcription 3 (STAT3), c-Jun N-terminal kinase (JNK), and BCL2-associated X (BAX) in the brain of 2-VO rats. Furthermore, 71 compounds were identified from the extract of MECD. Among them, liquiritin and isochlorogenic acid C gave inhibiting effects on the mRNA expression of Jnk. In addition, liquiritin and hesperetin were conformed with the inhibition of Jak2 transcription level in vitro experiments.

CONCLUSION

MECD has demonstrated a significant amelioration effect on cognitive dysfunction in VaD rats via JAK2/STAT3 and JNK/BAX signaling pathways, which represents an innovative insight into the "activate blood and eliminate phlegm" theory.

Brain-Derived Estrogen Regulates Neurogenesis, Learning and Memory with Aging in Female Rats

Although 17β-estradiol (E2) can be locally synthesized in the brain, whether and how brain-derived E2 (BDE2) impacts neurogenesis with aging is largely unclear. In this study, we examined the hippocampal neural stem cells, neurogenesis, and gliogenesis of 1, 3, 6, 14, and 18-month (Mon) female rats. Female forebrain neuronal aromatase knockout (FBN-ARO-KO) rats and letrozole-treated rats were also employed. We demonstraed that (1) the number of neural stem cells declined over 14-Mon age, and the differentiation of astrocytes and microglia markedly elevated and exhibited excessive activation. KO rats showed declines in astrocyte A2 subtype and elevation in A1 subtype at 18 Mon; (2) neurogenesis sharply dropped from 1-Mon age; (3) KO suppressed dentate gyrus (DG) neurogenesis at 1, 6 and 18 Mon. Additionally, KO and letrozole treatment led to declined neurogenesis at 1-Mon age, compared to age-matched WT controls; (4) FBN-ARO-KO inhibited CREB-BDNF activation, and decreased protein levels of neurofilament, spinophilin and PSD95. Notably, hippocampal-dependent spatial learning and memory was impaired in juvenile (1 Mon) and adulthood (6 Mon) KO rats. Taken together, we demonstrated that BDE2 plays a pivotal role for hippocampal neurogenesis, as well as learning and memory during female aging, especially in juvenile and middle age.

Dysregulation of the microbiota-brain axis during long-term exposure to polystyrene nanoplastics in rats and the protective role of dihydrocaffeic acid

Polystyrene nano-plastics (PS-NPs) can be accumulated in the food chain and can penetrate biological barriers to affect multiple physiological functions. However, the adverse effects of nano-plastics on mammals and the underlying mechanism still remain unknown. To fill the gaps, our study administrated low-dose PS-NPs (50 and 100 μg/L) for 24 consecutive weeks in rats. Behavioral and morphological evaluations were performed to assess the neurobehavoirs. A combined analysis of multiple omics was used to evaluate the dysfunctions of the gut-microbe-brain axis. After dihydrochalcone(NHDC) treatment in the PS-NPs rat model, the inflammation response and apoptosis process were assessed and proteomics was used to explore the underlying mechanism. Our results indicated that long-term exposure to low-dose PS-NPs could induce abnormal neurobehaviors and amygdaloid nucleus impairment, and stimulate inflammatory responses and apoptosis. Metagenomics results revealed that four microbial phyla including Proteobacteria, Firmicutes, Defferibacteres, and Bacteroidetes changed significantly compared to the control. Targeted metabolomics analysis in the feces showed alteration of 122 metabolites induced by the PS-NPs exposure, among which the content of dihydrocaffeic acid was significantly associated with the different microbial genera and pivotal differential metabolites in the amygdaloid nucleus. And NHDC treatment significantly alleviated PS-NP-induced neuroinflammation and apoptosis and the cyclic adenosine monophosphate(cAMP)/protein kinase A(PKA)/phosphorylated cAMP-response element binding protein(p-CREB)/plasma membrane calcium-transporting ATPase 2(Atp2b2) signaling pathway was identified in the proteomics. In conclusion, long-term exposure to low-dose PS-NPs has adverse effects on emotion through the dysregulation of the gut-brain axis, and dihydrocaffeic acid can alleviate these effects via the cAMP/PKA/p-CREB/Atp2b2 signaling pathway.

Elateriospermum tapos Yoghurt as a Therapeutic Intervention for Obesity-Associated Cognitive Impairments and Anxiety-like Behaviour in a High Fat Diet Maternal Obese Rat Model

Maternal obesity can be considered an intergenerational cycle and is also an important indicator of cognitive impairments. It is thought that using natural products is the best and safest way to combat maternal obesity and associated complications. Recent studies have shown that Elateriospermum tapos (E. tapos) contains bioactive compounds with anti-obesity effects, and yoghurt is a convenient medium for supplementing obese maternal rats with E. tapos extract. Thus, the aim of this study is to investigate the impact of E. tapos in yoghurt on maternally obese rats' cognitive function supplemented with a high-fat diet (HFD). In this study, 48 female Sprague-Dawley rats were used. The rats were fed HFD for a period of 16 weeks to induce obesity, after which they were allowed to mate. Upon confirmation of pregnancy, obese rats were given varying doses of E. tapos (5, 50, and 500 mg/kg) in yoghurt until postnatal (PND) day 21. On PND 21, the dams' body mass index (BMI), Lee index, abdominal circumference, oxidative status, and metabolic profile were measured. The behavioral tests (open field, place, and object recognition) were conducted on PND 21 to access memory. The results show that the 50 and 500 mg/kg E. tapos in yoghurt supplemented groups had similar BMI, Lee index, abdominal circumference, lipid profile, FBG, insulin, FRAP, and GSH levels, as well as a similar recognition index, in comparison with the control group supplemented with saline. In conclusion, the results of this study indicate that the newly formulated E. tapos in yogurt can act as an anti-obesity agent in maternal obesity, alleviate anxiety, and enhance hippocampal-dependent memory.

Remodulation Effect of Elateriospermum tapos Yoghurt on Metabolic Profile of Maternal Obesity Induced Cognitive Dysfunction and Anxiety-like Behavior in Female Offspring-An In Vivo Trial on Sprague Dawley Rats

Pre-pregnancy weight gain induces dysregulation in the metabolic profile of the offspring, thereby serving as a key factor for cognitive decline and anxiety status in the offspring. However, early probiotic supplementation during the gestational period is linked with improved metabolic health. At the same time, a natural plant known as Elateriospermum tapos (E. tapos) is proven to improve cognition and modulate the stress hormone due to its high concentration of flavonoids. However, the effects of medicinal plant integrated probiotics in F1 generations warrants further investigation. Thus, this study aimed to study the effect of E. tapos yoghurt on the maternal obesity induced cognitive dysfunction and anxiety in female offspring. In this study, female Sprague Dawley rats were fed with normal chow (n = 8) or high fat diet (n = 40) across pre-pregnancy, gestation, and weaning. The treatment with different concentrations of E. tapos yoghurt (5, 50, and 500 mg/kg/day) were initiated in the obese dams upon post coitum day 0 up to postnatal day 21 (PND 21). Female offspring were weaned on PND 21 and body mass index, waist circumference, lee index, behavior, metabolic parameter, and antioxidant status were analyzed. The result shows that the female offspring of the 500 mg/kg E. tapos yoghurt supplemented group shows a decreased level of insulin, fasting blood glucose, cholesterol, triglycerides, LDL, low fat tissue mass with a high level of HDL, and an increased level of antioxidant status in the hypothalamus. The behavioral assessment proves that the female offspring of the 500 mg/kg E. tapos yoghurt supplemented group exhibits a high recognition index on novel object/place with low anxiety-like behavior in an open field test. In conclusion, our data signify the beneficial effect of early intervention in obese dams on the transgenerational impact on female offspring's metabolic profile, cognitive performance, and anxiety-like behavior.

Early Intervention of Elateriospermum tapos Yoghurt in Obese Dams Mitigates Intergenerational Cognitive Deficits and Thigmotactic Behaviour in Male Offspring via the Modulation of Metabolic Profile

Maternal obesity is an intergenerational vicious cycle and one of the primary causes of cognitive deficits and high anxiety levels in offspring, which often manifest independently of sex. It is proven that curbing the intergenerational inheritance of obesity through early intervention during the gestation period has a positive outcome on the body composition, cognitive function, and anxiety level of the offspring. A recent discovery shows that the consumption of Elateriospermum tapos (E. tapos) seed extract modulates body mass and ameliorates stress hormones in obese dams, while a probiotic bacterial strain can cross the placenta and boost a child's memory. Thus, we speculate that probiotics are the best medium to integrate plant extract (E. tapos extract) to access the effect on the child's cognition. Thus, this study aimed to investigate the early intervention of E. tapos yoghurt in obese dams in the cognition and anxiety levels of male offspring. In this study, 40 female rats were fed with a high-fat diet (HFD) to induce obesity before pregnancy, while another 8 rats were fed with standard rat pellets for 16 weeks. Upon successful copulation, treatment was initiated for the obese dams up to the postnatal day (PND) 21. The groups included normal chow and saline (NS), HFD and saline (HS), HFD and yoghurt (HY), HFD and 5 mg/kg E. tapos yoghurt (HYT5), HFD and 50 mg/kg E. tapos yoghurt (HYT50), and HFD and 500 mg/kg E. tapos yoghurt (HYT500). All rats were euthanised on PND 21, and the body mass index (BMI), Lee index, and waist circumference were measured for the male offspring. Hippocampal-dependent memory tests and open field tests were conducted to access for cognition and anxiety status. Fasting blood glucose (FBG), total fat (%), insulin, leptin, lipid profile, and antioxidant parameter on serum and hypothalamus (FRAP and GSH) were accessed on PND 21. The result shows male offspring of 50 mg/kg-supplemented obese dams have comparable total fat (%), lipid profile, insulin level, FBG level, plasma insulin level, recognition index, low anxiety level, and improved hypothalamic FRAP and GSH levels to the normal group. In conclusion, this study highlights that the effect of early intervention of our novel formulation of E. tapos yoghurt in obese dams alleviates cognitive deficits and anxiety in male offspring by modulating metabolic profiles at the dose of 50 mg/kg.

Omega-3 fatty acids prevent nicotine withdrawal-induced exacerbation of anxiety and depression by affecting oxidative stress balance, inflammatory response, BDNF and serotonin metabolism in rats

Adolescents are known to be more vulnerable than adults to the adverse effects of nicotine dependence. In the present study, we aimed to investigate whether adolescent nicotine exposure, followed by a period of abstinence, could affect the anxiety- and depressive-like behaviors in rats. For this purpose, behavioral assessments were carried out using open field test, elevated plus maze and forced swimming test in male rats received chronic nicotine intake during adolescence followed by a period of abstinence in adulthood, compared to their control counterparts. In addition, O3 pre-treatment was done at three different doses to reveal whether it could prevent nicotine withdrawal effects. Then, animals were euthanized and the cortical concentrations of oxidative stress markers, inflammatory indices, brain-derived neurotrophic factor, serotonin and the enzymatic activity of monoamine oxidase-A were measured. Results indicated that nicotine withdrawal exacerbates the behavioral signs of anxiety through alteration of the brain oxidative stress balance, inflammatory response and serotonin metabolism. Moreover, we found that omega 3 pre-treatment significantly prevents the nicotine withdrawal-induced complications by restoration of changes in the mentioned biochemical indices. Moreover, the improving effects of O3 fatty acids were found to be dose-dependent in all experiments. Taken together, we would like to suggest the O3 fatty acids supplementation as a safe, inexpensive and effective strategy for prevention or amelioration of detrimental effects induced by nicotine withdrawal at cellular and behavioral levels.

Sonic hedgehog pathway as a new target of atypical antipsychotics: Revisiting of amisulpride and aripiprazole effects in a rat model of schizophrenia

OBJECTIVES

Schizophrenia is a chronic mental illness presented by cognitive deficits that precede its positive and negative symptoms. Sonic hedgehog (Shh)-pathway contributes to its pathophysiology. Shh has a role in neurogenesis as it regulates proliferation and survival of neural cells. In this study, effects of the anti-psychotics Amisulpride and/or Aripiprazole on the Shh-pathway and its relation to cognitive functions and neurogenesis in a rat model of schizophrenia were tested.

METHODS

60 male Wistar rats were allocated into the following groups: control, socially isolated, amisulpride and/or aripiprazole-treated groups. Rats were then subjected to behavioral, biochemical, and histopathological tests to assess the impact of these drugs on Shh-pathway.

KEY FINDINGS

Cognitive-dysfunction was evidenced in socially isolated group in novel object, three-chamber, and Morris water maze tests, associated by disorganised Shh-pathway proteins levels concentrations, increased glial fibrillary acidic protein (GFAP)-stained astrocytes. Treated groups favorably reversed these changes evidenced by increased Shh, transmembrane patched-1 and smoothened, glioma-associated-oncogene (GLI)-1 levels, dopamine-1 receptors and brain derived neurotrophic factor, and decreased GLI-3 protein, GFAP immune reaction in astrocytes and inflammatory markers compared to socially isolated group.

CONCLUSION

Amisulpride and/or aripiprazole have a favorable role in turning on Shh-pathway with subsequent beneficial cognitive and neurogenesis effects.

Role of imaging modalities and N-acetylcysteine treatment in sepsis-associated encephalopathy.. [DOI: 10.21203/rs.3.rs-2459747/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background Sepsis-associated encephalopathy is a severe complication due to systemic infection. Although early stages involve pathophysiological changes, detection using conventional imaging is challenging. Glutamate chemical exchange saturation transfer and diffusion kurtosis imaging can noninvasively investigate cellular and molecular events in the early stage of the disease by MRI. N-acetylcysteine, an antioxidant and precursor of glutathione, regulates the metabolism of the neurotransmitter glutamate and participates in neuroinflammation. We aimed to investigate the protective role of n-acetylcysteine in sepsis-associated encephalopathy using a rat model and monitor changes in the brain using magnetic resonance molecular imaging. Methods Bacterial lipopolysaccharide was injected intraperitoneally into the rats to induce a sepsis-associated encephalopathy model. The behavioural performance was assessed using the open field test. Tumour necrosis factor alpha and glutathione levels were detected biochemically. Imaging was performed using a 7.0-T MRI scanner. Protein expressions and cellular damage were assessed by western blotting and pathological staining, respectively. We also evaluated changes in the blood-brain barrier permeability by the Evans blue staining. Results The lipopolysaccharide-induced rats showed reduced anxiety and depression after treatment with n-acetylcysteine. Magnetic resonance molecular imaging can identify pathological processes at different stages of the disease. Furthermore, rats treated with n-acetylcysteine showed increased glutathione levels and decreased tumour necrosis factor alpha, suggesting enhanced antioxidant capacity and inhibition of inflammatory processes, respectively. Western blot analysis showed a reduced expression of nuclear factor kappa B (p50) protein after treatment, suggesting that n-acetylcysteine inhibits inflammation via this signalling pathway. Finally, n-acetylcysteine treated rats also showed reduced cellular damage by pathology and reduced extravasation of their blood-brain barrier by Evan Blue staining. Conclusion This study showed that n-acetylcysteine might be a therapeutic option for sepsis-associated encephalopathy and other neuroinflammatory diseases. Furthermore, non-invasive ‘dynamic visual monitoring’ of the physiological and pathological changes related to sepsis-associated encephalopathy was achieved for the first time using magnetic resonance molecular imaging, which provides a more sensitive imaging basis for early clinical diagnosis, identification, and prognosis.

Prenatal ethanol exposure leads to persistent anxiety-like behavior during adulthood indicated by reduced horizontal and vertical exploratory behaviors

Background

Fetal alcohol spectrum disorders (FASD) caused by prenatal ethanol exposure (PE) consist of many cognitive/behavioral deficits. Studies have reported that PE leads to impairments of learning and memory, attention, executive function, and anxiety. Open field (OF) is a common behavioral model which offers comprehensive ethological information. Here, we analyzed multiple parameters of OF to examine anxiety behavior and habituation after PE.

Material and Methods

Pregnant Sprague Dawley rats were gavaged twice/day with 0 or 3 g/kg/treatment ethanol (15% w/v) during gestational day (GD) 8-20, mimicking second-trimester heavy PE in humans. The control and PE adult offspring were subjected to OF task in different ambient light levels with or without acute stress.

Results

Prenatal ethanol exposure did not influence the overall locomotor activities or habituation in the OF. In lower ambient light, no PE effects could be detected. In higher ambient light, female PE rats showed less activities in the center zone, indicative of increased anxiety. Males show lower activities in the center zone only after acute stress. Rats spent <2% of the time in the center zone compared to >75% of the time in the corner zone where they engaged in frequent rearing activities (vertical exploration; exploratory rearing). Prenatal ethanol exposure led to lower rearing activities in the corner in both males and females. Acute stress masks the PE effects in males but not in females.

Discussion

The results support that heavy PE leads to persistent anxiety-like behavior during adulthood in both sexes. This conclusion is supported by using multiple parameters of exploratory behavior in the OF, including the rearing activities in the corner to reach reliable quantification of anxiety-like behavior.

Astragaloside VI Ameliorates Post-Stroke Depression via Upregulating the NRG-1-Mediated MEK/ERK Pathway

BACKGROUND

Post-stroke depression (PSD) has been identified as one of the most commonly occurring complications attributed to stroke. Astragaloside VI (AsVI), which is an active Radix Astragali (AR)-derived compound, has been reported to be a potential drug for post-stroke therapy, but its effects on PSD and the underlying mechanisms remain uncovered.

METHODS

In this study, healthy male SD rats underwent a middle cerebral artery occlusion (MCAO) stroke model. To create a PSD model, these rats were then kept in isolated houses and subjected to chronic unpredictable mild stress. The rats were examined every five days for a series of behavioral tests of depression. The antidepressant properties of AsVI were also investigated in vitro in a corticosterone (CORT)-induced major depression model using a CCK-8 assay. The release of neurotransmitters dopamine (DA)/5-hydroxytryptamine (5-HT) was measured using HPLC. The expression of the neurotrophic factor Neuregulin 1 (NRG-1) in rat brain tissues was detected by immunostaining. The protein expression of NRG-1, p-MEK1, and p-ERK1/2 was analyzed utilizing western blotting.

RESULTS

AsVI treatment significantly reduced depression-like behaviors in PSD rats and attenuated the CORT-induced apoptotic cell death in neuronal PC-12 cells. Besides, AsVI treatment remarkably prevented the decrease of the levels of DA and 5-HT in the PSD rat brains and in CORT-induced PC-12 cells. Furthermore, AsVI treatment upregulated the NRG-1-mediated MEK/ERK pathway, which is associated with the improvement of PSD.

CONCLUSIONS

These findings suggest that AsVI could improve PSD at least partially by upregulating NRG-1-mediated MEK/ERK pathway. AsVI could be a novel therapeutic option for treating PSD.

Effects of brain-derived neurotrophic factor (BDNF) on the Schizophrenia model of animals

BACKGROUND

Schizophrenia（SCZ）is a common clinically chronic psychiatric disease, and there have no effective specific therapeutic drugs in clinical practice currently. Studies have shown that the expression level of brain-derived neurotrophic factor (BDNF) in schizophrenics has decreased, so the expression level of BDNF has always been one of the evaluation indicators of SCZ. The neurotrophic factor hypothesis believes that increase or decrease of the expression level of BDNF may be one of the pathophysiological basis of SCZ.

METHODS

In this study, schizophrenic mice model with MK-801-induced glutamate dysfunction was established, and two doses of BDNF were administered to schizophrenic mice by intranasal administration. The four groups of mice: Control group, Model group, BDNF-20, BDNF-100 performed a series of behavioral tests to explore the effects of BDNF on sensory motor gating, anxiety, depression, social interaction, spontaneous activity, and memory in schizophrenic mice. Transcriptome sequencing of the BDNF high group and Model group in prefrontal cortex and hippocampus, using Metascape for gene function annotation and enrichment pathway analysis, to obtain BDNF transcription regulation information, understand the molecular mechanism of BDNF in SCZ further. Subsequently，immunofluorescence detected the effects of BDNF on neurons and glial cells in the prefrontal cortex and hippocampus.

CONCLUSION

The results show that BDNF can improve the behavior of SCZ by regulating the construction of the nervous system, affecting the growth and distribution of neurons and glial cells, and changing inflammation and apoptosis in the brain.

Carrot-based fermentation juice rich in sleep-promoting components improved sleep in mice

The impact of fermentation by Levilactobacillus brevis YSJ3 on sleep-promoting components (SPCs) of carrot juice was evaluated. The contents of acetic acid, isovaleric acid, butyric acid, and γ-aminobutyric acid (GABA) significantly increased after fermentation. The beneficial effects of fermented carrot juice (FCJ) on sleep were evaluated in animal experiments. Behavioral test reveal SPCs-enriched FCJ could effectively relieve anxiety. The sleep duration in the FCJ group were extended compared to the control (NC) group and the unfermented carrot juice (UCJ) group. Moreover, the relative abundances of Ruminiclostridium and Akkermansia in the FCJ group and PC group, respectively, increased significantly, compared to the NC group the UCJ group. The contents of gut short-chain fatty acids in the FCJ group were significantly higher than that in the NC group and the UCJ group. The levels of GABA and 5-hydroxytryptamine in the brain for the FCJ group also increased significantly, compared to the NC group and the UCJ group. It indicated that SPCs-enriched FCJ effectively improved sleep in mice, which might be related to the fermentation of carrot juice and the compounds produced during the fermentation.

Effect of Acute Cold Stress on Neuroethology in Mice and Establishment of Its Model

Cold environment is an inevitable stress source for humans and livestock in cold areas, which easily induce a cold stress response and then cause a series of abnormal changes in energy metabolism, neuroendocrine system, behavior and emotion. Homeostasis is maintained by the unified regulation of the autonomic nervous system, endocrine system, metabolism and behavior under cold exposure. Behavior is an indispensable part of the functional regulation of the body to respond to environmental changes. At present, the behavioral changes caused by cold exposure are unclear or even chaotic due to the difficulty of defining cold stress. Therefore, this study aims to systematically observe the changes in spontaneous movement, exploratory behavior and anxiety of mice under different intensity cold exposure and summarize the characteristics and behavior traits combined with relevant blood physiological indexes under corresponding conditions. Mice models of cold stress with different intensities were established (cold exposure gradients were 22 °C, 16 °C, 10 °C and 4 °C, and time gradients of each temperature were 2 h, 4 h, 6 h, 8 h, 10 h and 12 h). After the corresponding cold exposure treatment, mice immediately carried out the open field test(OFT) and elevated plus maze test (PMT) to evaluate their spontaneous movement, exploratory behavior and anxiety. Subsequently, blood samples were collected and used for the determination of corticosterone (Cort), corticotropin-releasing hormone (CRH), epinephrine (E), norepinephrine (NE), dopamine (DA) and 5-hydroxytryptamine (5-HT) by enzyme-linked immunosorbent assay (ELISA). Spontaneous movement of mice increased under 22 °C cold exposure, but their exploration behavior did not significantly change, and their anxiety improved at the initial stage. The spontaneous movement and anxiety of mice increased in the initial stage and decreased in the later stage under cold exposure at 16, 10 and 4 °C and the exploratory behavior was inhibited. The hypothalamic-pituitary-adrenal (HPA) axis and locus coeruleus-noradrenergic (LC/NE) system were activated by cold stress and fluctuated with different intensities of cold exposure. Meanwhile, serum DA increased, and 5-HT was the opposite under different intensities of cold exposure. In conclusion, mild acute cold exposure promoted the spontaneous movement, increased exploratory behavior and improved anxiety. As the intensity of cold exposure increases, cold exposure had a negative effect on spontaneous movement, exploratory behavior and emotion. The physiological basis of these behavioral and emotional changes in mice under different intensity cold stimulation is the fluctuation of Cort, CRH, E, NE, DA and 5-HT.

Inhibition of GABAAR or Application of Lactobacillus casei Zhang Alleviates Ulcerative Colitis in Mice: GABAAR as a Potential Target for Intestinal Epithelial Renewal and Repair

Emerging evidence indicates that the gamma−aminobutyric acid type A receptor (GABA_AR) and Lactobacillus casei Zhang regulate colitis in a variety of ways, such as by participating in host immune and inflammatory responses, altering the gut microbiota, and influencing intestinal barrier function. However, not much is known about the mechanisms by which GABA_AR and L. casei affect colon epithelial cell renewal and the interaction between GABA_AR and L. casei during this process. To elucidate this, we established a dextran sulfate sodium (DSS)−induced model and measured the mouse body weights, colon length, the disease activity index (DAI), and histological scores. Our results indicated that inhibition of GABA_AR alleviated the DSS−induced colitis symptoms, resulting in less weight loss and more intact colon tissue. Moreover, treatment with bicuculline (Bic, a GABA_AR inhibitor) increased the levels of PCNA, β−catenin, and TCF4 in mice with colitis. Interestingly, open field test performances showed that inhibition of GABA_AR also attenuated colitis−related anxiety−like behavior. By 16S RNA gene sequencing analysis, we showed that inhibition of GABA_AR partially reversed the gut dysbacteriosis of DSS−induced mice and increased the abundance of beneficial bacteria. Additionally, L. casei Zhang supplementation inhibited the expression of GABA_AR in mice with colitis, promoted the proliferation and renewal of colon epithelial cells, and alleviated anxiety−like behavior and intestinal microflora disorder in mice. Thus, GABA_AR plays a key role in the beneficial effects of L. casei on DSS−induced colitis in mice.

Taurine ameliorates volatile organic compounds-induced cognitive impairment in young rats via suppressing oxidative stress, regulating neurotransmitter and activating NMDA receptor

Long-term exposure to volatile organic compounds (VOCs) in children leads to intellectual and cognitive impairment. Taurine is an essential nutritional amino acid for children, which can improve neurological development in children. However, the neuroprotective effect of taurine on VOCs-induced cognitive impairment in children remains unclear. The aim of this study was to investigate the neuroprotective effects of taurine on VOCs-induced cognitive impairment in young rats. The rats were nose-only exposed to VOCs for a period of 4 weeks to create a model of cognitive impairment, and 0.5% and 1% taurine in tap water were administered throughout the trial period, respectively. Our results showed that young rats adjusted the recovery of their physiological functions by voluntarily increasing the intake of taurine in tap water when exposed to excessive VOCs by inhalation. In addition, taurine enhanced grasp, shortened the latency period of escape, and improved the learning and memory function of young rats. Moreover, taurine decreased malondialdehyde (MDA), γ-aminobutyric acid (GABA), Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), Urea, Creatinine (CREA) and injury biomarker level, enhanced superoxide dismutase (SOD), reduced glutathione (GSH) and glutamic acid (Glu) activities, up-regulated the protein expression of brain derived neurotrophic factor (BDNF) and N-Methyl-d-aspartate receptor 1 (NMDAR1) in model rats, and in most of cases 1% but not 0.5%, ameliorated the defects induced by VOCs. Collectively, these findings suggested that taurine protected against VOCs-induced cognitive-behavioral impairment in young rats through inhibiting oxidative stress and regulating neurotransmitter homeostasis. In addition, taurine were capable of restoring abilities of learning and memory in young rats exposed to VOCs by activating the N-Methyl-d-aspartate (NMDA) receptor. The findings suggest taurine as a potential novel drug for the treatment of cognitive behavioral disorders in children.

Triphenyl phosphate disturbs placental tryptophan metabolism and induces neurobehavior abnormal in male offspring

Epidemiological studies have shown that prenatal triphenyl phosphate (TPhP) exposure is related to abnormal neurobehavior in children. However, the neurodevelopmental toxicity of TPhP in mammals is limited. To study the neurodevelopmental toxicity of TPhP in mammals and investigate the underlying mechanism, we used a mouse intrauterine TPhP exposure model. We measured the inflammatory factors (IL-6, TNFα) and NFκB levels, and tryptophan metabolism in placentae, detected the fetal brain transcriptome, hippocampal neuron development and neurobehavioral in the male offspring. The results showed that the protein level of IL-6, TNFα and NFκB in the placenta of the TPhP treatment group (1, 5 mg/kg) were significantly increased. Change of the protein level of these pro-inflammatory factors in maternal serum or fetal brain was not observed. Expression of genes along tryptophan-serotonin metabolism pathway were significantly decreased. While, the concentration of 5-HT levels in the placenta or fetal brain were significantly increased. Consistent with the increased 5-HT, the Nissl body was reduced in the hippocampus of treatment group. The expression of serotonergic neuron gene markers including Tph2, Htr1A, Htr2A, Pet1 and Lmx1b in the hippocampus of treatment group was significantly decreased. The neurobehavioral test showed that TPhP decreased center time that represent anxiety-like behavior, and reduced learning and memory in male offspring. Meanwhile, expression of genes along tryptophan-kynurenine metabolism pathway were significantly increased. The result of the transcriptome analysis of fetal brain showed that the differentially expressed genes are mainly involved in the transcription regulation of DNA as a template in the nucleus, and the enriched pathways are mainly signal pathways regulated by axon guidance and neurotrophic factors, dopaminergic and cholinergic synapses, suggest that not only serotonergic neuronal was affected. Overall, this study demonstrates that TPhP has the potential to induce placental inflammatory response in the placenta, disturb placental tryptophan metabolism, compromise the neuronal development and synaptic transmission, and cause abnormal neurobehavior in male offspring.

Decrease in the rewarding value of spatial novelty due to the contamination of the stimulus field with light - evidence from a free exploration test involving rats

It has been shown that rearranging the spatial properties of a familiar environment consistently elicits a positive response in rats directed toward the source of novelty. Previous studies have been conducted under red light or darkness. The purpose of this study was to test the effect of rearranging the spatial properties of a familiar environment in conjunction with a change in lighting conditions. The results have shown specific effects of the light presence and its intensity on different behavioral measures. We propose that this study provides a basis for hypothesizing a two-way mechanism of the behavioral response to light regulation in rats. The first is based on ON/OFF states. This level may be related to fundamental, evolutionarily early, emergent components of behavioral antipredator adaptations. Another level of behavioral regulation involves mechanisms sensitive to light intensity. These appear to be involved in the regulation of more advanced behavioral acts, such as exploratory responses. This may suggest that light intensity analysis may require the involvement of more advanced cognitive components in the behavioral regulation system.

Under or Absent Reporting of Light Stimuli in Testing of Anxiety-Like Behaviors in Rodents: The Need for Standardization

Behavioral neuroscience tests such as the Light/Dark Test, the Open Field Test, the Elevated Plus Maze Test, and the Three Chamber Social Interaction Test have become both essential and widely used behavioral tests for transgenic and pre-clinical models for drug screening and testing. However, as fast as the field has evolved and the contemporaneous involvement of technology, little assessment of the literature has been done to ensure that these behavioral neuroscience tests that are crucial to pre-clinical testing have well-controlled ethological motivation by the use of lighting (i.e., Lux). In the present review paper, N = 420 manuscripts were examined from 2015 to 2019 as a sample set (i.e., n = ~20–22 publications per year) and it was found that only a meager n = 50 publications (i.e., 11.9% of the publications sampled) met the criteria for proper anxiogenic and anxiolytic Lux reported. These findings illustrate a serious concern that behavioral neuroscience papers are not being vetted properly at the journal review level and are being released into the literature and public domain making it difficult to assess the quality of the science being reported. This creates a real need for standardizing the use of Lux in all publications on behavioral neuroscience techniques within the field to ensure that contributions are meaningful, avoid unnecessary duplication, and ultimately would serve to create a more efficient process within the pre-clinical screening/testing for drugs that serve as anxiolytic compounds that would prove more useful than what prior decades of work have produced. It is suggested that improving the standardization of the use and reporting of Lux in behavioral neuroscience tests and the standardization of peer-review processes overseeing the proper documentation of these methodological approaches in manuscripts could serve to advance pre-clinical testing for effective anxiolytic drugs. This report serves to highlight this concern and proposes strategies to proactively remedy them as the field moves forward for decades to come.

Lactobacillus plantarum-derived postbiotics prevent Salmonella-induced neurological dysfunctions by modulating gut-brain axis in mice

Postbiotics are the inactive bacteria and/or metabolites of beneficial microbes which have been recently found to be as effective as their live probiotic. This study aimed to evaluate the benefits of Lactobacillus plantarum (LP)-derived postbiotics on ameliorating Salmonella-induced neurological dysfunctions. Mice were pretreated with LP postbiotics (heat-killed bacteria or the metabolites) or active bacteria, and then challenged with Salmonella enterica Typhimurium (ST). Results showed that LP postbiotics, particularly the metabolites, effectively prevented ST infection in mice, as evidenced by the inhibited weight loss, bacterial translocation, and tissue damages. The LP postbiotics markedly suppressed brain injuries and neuroinflammation (the decreased interleukin (IL)-1β and IL-6, and the increased IL-4 and IL-10). Behavior tests indicated that LP postbiotics, especially the metabolites, protected mice from ST-induced anxiety and depressive-like behaviors and cognitive impairment. A significant modulation of neuroactive molecules (5-hydroxytryptamine, gamma-aminobutyric acid, brain-derived neurotrophic factor, dopamine, acetylcholine, and neuropeptide Y) was also found by LP postbiotic pretreatment. Microbiome analysis revealed that LP postbiotics optimized the cecal microbial composition by increasing Helicobacter, Lactobacillus and Dubosiella, and decreasing Mucispirillum, norank_f_Oscillospiraceae, and Eubacterium_siraeum_group. Moreover, LP postbiotics inhibited the reduction of short-chain fatty acids caused by ST infection. Pearson's correlation assays further confirmed the strong relationship of LP postbiotics-mediated benefits and gut microbiota. This study highlights the effectiveness of postbiotics and provide a promising strategy for preventing infection-induced brain disorders by targeting gut–brain axis.

Neuronal MD2 induces long-term mental impairments in septic mice by facilitating necroptosis and apoptosis

Sepsis-associated encephalopathy (SAE) is a complication of sepsis with high morbidity rates. Long-lasting mental health issues in patients with SAE result in a substantial decrease in quality of life. However, its underlying mechanism is unclear, and effective treatments are not available. In the current study, we explored the role of apoptosis and necroptosis related to mental dysfunction in sepsis. In a mouse model of sepsis constructed by cecal ligation and puncture (CLP), altered behavior was detected by the open field, elevated-plus maze and forced swimming tests on the fourteenth day. Moreover, apoptosis- and necroptosis-associated proteins and morphological changes were examined in the hippocampus of septic mice. Long-lasting depression-like behaviors were detected in the CLP mice, as well as significant increases in neuronal apoptosis and necroptosis. Importantly, we found that apoptosis and necroptosis were related according to Ramsay’s rule in the brains of the septic mice. Inhibiting myeloid differentiation factor 2 (MD2), the crosstalk mediator of apoptosis and necroptosis, in neurons effectively reduced neuronal loss and alleviated depression-like behaviors in the septic mice. These results suggest that neuronal death in the hippocampus contributes to the mental impairments in SAE and that inhibiting neuronal MD2 is a new strategy for treating mental health issues in sepsis by inhibiting necroptosis and apoptosis.

Neural signals implicated in the processing of appetitive and aversive events in social and non-social contexts

In 2014, we participated in a special issue of Frontiers examining the neural processing of appetitive and aversive events. Specifically, we reviewed brain areas that contribute to the encoding of prediction errors and value versus salience, attention and motivation. Further, we described how we disambiguated these cognitive processes and their neural substrates by using paradigms that incorporate both appetitive and aversive stimuli. We described a circuit in which the orbitofrontal cortex (OFC) signals expected value and the basolateral amygdala (BLA) encodes the salience and valence of both appetitive and aversive events. This information is integrated by the nucleus accumbens (NAc) and dopaminergic (DA) signaling in order to generate prediction and prediction error signals, which guide decision-making and learning via the dorsal striatum (DS). Lastly, the anterior cingulate cortex (ACC) is monitoring actions and outcomes, and signals the need to engage attentional control in order to optimize behavioral output. Here, we expand upon this framework, and review our recent work in which within-task manipulations of both appetitive and aversive stimuli allow us to uncover the neural processes that contribute to the detection of outcomes delivered to a conspecific and behaviors in social contexts. Specifically, we discuss the involvement of single-unit firing in the ACC and DA signals in the NAc during the processing of appetitive and aversive events in both social and non-social contexts.

Resilience of females to acute blood–brain barrier damage and anxiety behavior following mild blast traumatic brain injury

Low-level blast exposure can result in neurological impairment for military personnel. Currently, there is a lack of experimental data using sex as a biological variable in neurovascular outcomes following blast exposure. To model mild blast traumatic brain injury (mbTBI), male and female rats were exposed to a single 11 psi static peak overpressure blast wave using the McMillan blast device and cohorts were then euthanized at 6 h, 24 h, 7 d and 14 d post-blast followed by isolation of the amygdala. After mbTBI, animals experience immediate bradycardia, although no changes in oxygen saturation levels or weight loss are observed. Male mbTBI animals displayed significantly higher levels of anxiety-like behavior (open field and elevated plus maze) compared to male sham groups; however, there was no anxiety phenotype in female mbTBI animals. Blast-induced neurovascular damage was explored by measuring expression of tight junction (TJ) proteins (zonula occludens-1 (ZO-1), occludin and claudin-5), glial fibrillary acidic protein (GFAP) and astrocyte end-feet coverage around the blood–brain barrier (BBB). Western blot analysis demonstrates that TJ protein levels were significantly decreased at 6 h and 24 h post-mbTBI in male rats, but not in female rats, compared to sham. Female animals have decreased GFAP at 6 h post-mbTBI while male animals display decreased GFAP expression at 24 h post-mbTBI. By 7 d post-mbTBI, there were no significant differences in TJ or GFAP levels between groups in either sex. At 24 h post-mbTBI, vascular integrity and astrocytic end-feet coverage around the BBB was significantly decreased in males following mbTBI. These results demonstrate that loss of GFAP expression may be due to astrocytic damage at the BBB. Our findings also demonstrate sex differences in acute vascular and behavioral outcomes after single mbTBI. Female animals display a lack of BBB pathology after mbTBI corresponding to improved acute neuropsychological outcomes as compared to male animals.

Effect of Xiongmatang Extract on Behavioral and TRPV1-CGRP/CGRP-R Pathway in Rats With Migraine

Migraine is a complex neurovascular disease, which seriously affects the quality of life in patients. This study aimed to evaluate the effect of Xiongmatang (XMT) extract on rats with migraine induced by inflammatory soup and the underlying mechanisms. First, 1 week after dural catheterization, inflammatory soup was injected through a microsyringe to stimulate the dura of rats for 6 times (12 days), once every 2 days, 10 μL each time, to establish a migraine model. According to pain threshold analysis, behavioral change detection, and pathological analysis, the effects of XMT extract on rats with migraine were evaluated. The positive, mRNA and protein expression of related factors were detected by immunohistochemistry, RT-QPCR, and Western blot analysis to elucidate the underlying mechanism. XMT extract improved the behavioral performance of rats, and improve the pathological changes in the trigeminal nerve in rats. Further experimental results show that XMT extract regulated the expression of migraine-related factors in the trigeminal nerve, manifested as transient receptor potential vanilloid 1 (TRPV1), calcitonin-gene-related peptide (CGRP), calcitonin receptor-like receptor (CRLR), and receptor activity-modifying protein 1 (RAMP1) positive expression, mRNA expression, and protein expression reduction. XMT extract can significantly improved the behavioral performance of rats with migraine, and its mechanism of action might involve regulating the activity of TRPV1-CGRP/CGRP-R pathway.

β-Hydroxybutyric acid attenuates heat stress-induced neuroinflammation via inhibiting TLR4/p38 MAPK and NF-κB pathways in the hippocampus

Heat stress causes many pathophysiological responses in the brain, including neuroinflammation and cognitive deficits. β-Hydroxybutyric acid (BHBA) has been shown to have neuroprotective effects against inflammation induced by lipopolysaccharide. The aim of the present study was to evaluate the effects of BHBA on neuroinflammation induced by heat stress, as well as the underlying mechanisms. Mice were pretreated with vehicle, BHBA or minocycline (positive control group) and followed by heat exposure (43°C) for 15 min for 14 days. In mice subjected to heat stress, we found that treatment with BHBA or minocycline significantly decreased the level of serum cortisol, the expressions of heat shock protein 70 (HSP70), and the density of c-Fos⁺ cells in the hippocampus. Surprisingly, the ethological tests revealed that heat stress led to cognitive dysfunctions and could be alleviated by BHBA and minocycline administration. Further investigation showed that BHBA and minocycline significantly attenuated the activation of microglia and astrocyte induced by heat stress. Pro-inflammatory cytokines were attenuated in the hippocampus by BHBA and minocycline treatment. Importantly, compared with the heat stress group, mice in the BHBA treatment group and positive control group experienced a decrease in the expressions of toll-like receptor 4 (TLR4), phospho-p38 (p-p38), and nuclear factor kappa B (NF-κB). Our results elucidated that BHBA inhibits neuroinflammation induced by heat stress by suppressing the activation of microglia and astrocyte, and modulating TLR4/p38 MAPK and NF-κB pathways. This study provides new evidence that BHBA is a potential strategy for protecting animals from heat stress.

Correlation between microRNA-320 and postoperative delirium in patients undergoing tibial fracture internal fixation surgery

Background

Although the incidence of postoperative delirium (POD) in the elderly after surgery are rising as individuals are living longer, the pathogenesis of POD remains poorly understood. It has been suggested that miRNA-320 may play a role in POD based on animal study and human study.

Methods

We first carried out an animal study, and designed and conducted a human study based on the result of animal study. The aged rats were randomly assigned to five groups: the control (C), anesthesia and surgery (AS), saline (NS), agomir-320 (AG), and antagomir-320 (AT) groups. Postoperative spatial learning and memory in rats were analyzed by the Morris water maze and the open field tests. The plasma levels of insulin-like growth factor-1 (IGF-1), amyloid precursor protein (APP) proteins, miRNA320 and IGF-1mRNA were measured by ELISA and qRT-PCR, respectively. A total of 240 Chinese Han patients over 65 years who underwent tibial fracture internal fixation were included in the PNDABLE study. POD cases and non-POD controls (1:1 matched) were selected by an anesthesiologist using Confusion Assessment Method.

Results

For Group AS, the escape latency was significantly longer and the ratio of time spent in the target quadrant was significantly reduced, APP and miR-320 were upregulated and IGF-1mRNA was downregulated compared with Group C. For Group AG, the escape latency was significantly longer and the ratio of time spent in the target quadrant was significantly reduced, APP and miR-320 were upregulated and IGF-1mRNA was downregulated compared with Group AS. For Group AT, the escape latency was significantly reduced and the ratio of time spent in the target quadrant was significantly longer, APP and miR-320 were downregulated and IGF-1mRNAwas upregulated compared with Group AS. Compared with NPOD patients, the expressions of plasma miR-320 and APP protein were increased and the expression of plasma IGF-1 mRNA was decreased in POD patients after surgery.

Conclusions

MiRNA-320 might play a role in up-regulating the levels of IGF-1mRNA and APP protein, which offered a new target for POD treatment.

Trial registration

Correlation of perioperative neurocognitive disorders with lifestyle and biomarkers. ChiCTR2000033439. Registered 1 June 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01612-w.

Inhibition of ROCK2 kinase activity improved behavioral deficits and reduced neuron damage in a DEACMP rat model

The main pathological changes that occur in delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) are extensive demyelination of brain white matter and neuron damage. Previous studies suggested that demyelination and neuron injury are related to activating the Rho/ROCK signaling pathway. Inhibition of the Rho/ROCK signaling pathway can alleviate neuron injury and promote myelin repair. This study utilized a DEACMP model in which rats were prepared by space injection of CO gas intraperitoneally (CO group), and the association between the Rho/ROCK signaling pathway and DEACMP was investigated. The ROCK2 kinase inhibitor Y-27632 was used to prevent the effects of the DEACMP model to elucidate its protective mechanism. The results demonstrated that the cognitive and motor functions were significantly impaired, and the GFAP, NSE, RhoA, and ROCK2 protein levels were significantly increased in the CO group within three weeks after the model was established. After Y-27632 intervention, the cognitive and motor functions of the CO+Y-27632 group were significantly improved within three weeks after the model was established. In the CO+Y-27632 group, the RhoA, ROCK2, GFAP, and NSE (indicating neuron injury) protein levels decreased significantly, and the MBP protein levels (indicating myelin repair) increased significantly within three weeks after the model was established. These results suggested that the pathogenesis of DEACMP was associated with activation of the Rho/ROCK pathway and that Y-27632 inhibited ROCK2 kinase activity in the CO exposed rats, resulting in improved behavioral deficits, reduced neuron damage, and promotion of myelin repair. Therefore, Y-27632 might be a potentially effective drug for the treatment of DEACMP-induced brain damage.

Intranasal Hydrogel of Armodafinil Hydroxypropyl-β-Cyclodextrin Inclusion Complex for the Treatment of Post-Traumatic Stress Disorder

Armodafinil inclusion complex (AIC) hydrogel was prepared and evaluated for its therapeutic effect on Post-traumatic Stress Disorder (PTSD). After computer simulation and physicochemical property investigation, the AIC was formed by lyophilization of armodafinil with ethanol as solvent and hydroxypropyl-beta-cyclodextrin (HP-β-CD) aqueous solution, in which the molar ratio of armodafinil and HP-β-CD was 1–1. The AIC encapsulation efficiency (EE) was (90.98 ± 3.72)% and loading efficiency (LE) was (13.95 ± 0.47)% and it increased the solubility of armodafinil in aqueous solution to 21 times. AIC hydrogel was prepared by adding AIC to methylcellulose (MC) hydrogels (3.33% w/v), and its higher drug release amount and slower release rate were testified by the in-vitro release assay and the rheological test. The mucosa irritation of AIC hydrogel was also evaluated. Healthy group, Model group, Sertraline group with 30 mg/kg sertraline gavage, AIC Hydrogel group with 20 mg/kg AIC hydrogel intranasal administration and AIC Aqueous Solution group with 20 mg/kg AIC aqueous solution gavage were set up for the treatment of mice with PTSD generated from foot shock method. Based on freezing response test in fear-conditioning box and open field test, compared with other groups, PTSD mice in AIC Hydrogel group showed significant improvement in behavioral parameters after 11 days of continuous drug administration and 5 days of drug withdrawal. After sacrifice, the plasma CORT level of PTSD mice in AIC Hydrogel group was elevated compared to Model group. Besides, the western blot (WB) of hippocampal brain-derived neurotrophic factor (BDNF) and amygdala dopamine transporter (DAT) immunohistochemistry sections indicated that AIC hydrogel had a protective effect on the brain tissue of PTSD mice. The brain targeting of intranasal administration was evaluated by fluorescence imaging characteristics of Cy7 hydrogel in the nasal route of drug administration, pharmacokinetics and in-vivo distribution of armodafinil. In short, AIC hydrogel is a promising formulation for the treatment of PTSD based on its high brain delivery and anti-PTSD effect.

Maternal Deprivation Increased Vulnerability to Depression in Adult Rats Through DRD2 Promoter Methylation in the Ventral Tegmental Area

OBJECTIVE

Early life adversity is a risk factor for depression in adulthood; however, the underlying mechanisms are not well understood. This study aims to investigate the effect of DNA methylation of DRD2 gene on early life stress-induced depression in adult rats.

METHODS

Newborn Sprague-Dawley rats were randomly assigned to four groups: maternal deprivation group (MD), chronic unpredictable stress (CUS) group, maternal deprivation plus chronic unpredictable stress (MD/CUS) group, and normal control group (NOR). Behaviors were measured by open field test (OFT), sucrose preference test (SPT), and Original Research Article forced swimming test (FST). Fecal CORT level was detected by ELISA. Bisulfite amplicon sequencing PCR was used to assess methylation levels of DRD2 promoter.

RESULTS

CUS and MD/CUS rats had a significantly shorter total distance, longer immobility time, and higher CORT level, while MD and MD/CUS rats had a significantly lower percentage of central distance, more feces, lower rate of sucrose preference, and lower levels of DRD2 protein and mRNA in the VTA than NOR rats. CUS rats showed a significantly higher DRD2 mRNA and protein levels in the VTA than NOR rats. CUS, MD, and MD/CUS rats showed a significantly higher level of DRD2 promoter methylation than NOR rats. CORT level was significantly correlated with the sucrose preference rate in SPT, the immobility time in FST, the total distance, and the number of fecal pellets in OFT. DRD2 protein level was significantly correlated with the sucrose preference rate and the number of fecal pellets. DRD2 mRNA level was significantly correlated with the percentage of central distance and the number of fecal pellets in OFT. The level of DRD2 promoter methylation was significantly correlated with the sucrose preference rate, immobility time, total distance, the percentage of central distance, and the number of fecal pellets.

CONCLUSIONS

Early life MD increased vulnerability to stress-induced depressive-like behavior in adult rats. Enhanced DRD2 promoter methylation in the VTA may increase the susceptibility to depression.

Global brain delivery of neuroligin 2 gene ameliorates seizures in a mouse model of epilepsy

BACKGROUND

Despite the increasing availability of effective drugs, around one-third of patients with epilepsy are still resistant to pharmacotherapy. Gene therapy has been suggested as a plausible approach to achieve seizure control, in particular for patients with focal epilepsy. Because seizures develop across wide spans of the brain in many forms of epilepsy, global delivery of the vectors is necessary to tackle such generalized seizures. Neuroligin 2 (NL2) is a postsynaptic cell adhesion molecule that induces or strengthens inhibitory synaptic function by specifically combining with neurexin 1.

METHODS

In the present study, we applied an adeno-associated virus (AAV) type 9 vector expressing NL2 to modulate neuronal excitability in broad areas of the brain in epileptic (EL) mice, a model of polygene epilepsy. We administered the AAV vector expressing Flag-tagged NL2 under the synapsin I promoter (AAV-NL2) via cardiac injection 6 weeks after birth.

RESULTS

Significant reductions in the duration, strength and frequency of seizure were observed during a 14-week observation period in NL2-treated EL mice compared to untreated or AAV-green fluorescent protein-treated EL mice. No behavioral abnormality was observed in NL2-treated EL mice in an open-field test. Immunohistochemical examination at 14 weeks after AAV-NL2 injection revealed the expression of exogenous NL2 in broad areas of the brain, including the hippocampus and, in these areas, NL2 co-localized with postsynaptic inhibitory molecule gephyrin.

CONCLUSIONS

Global brain delivery of NL2 by systemic administration of AAV vector may provide a non-invasive therapeutic approach for generalized epilepsy.

Helicid Reverses the Effect of Overexpressing NCALD, Which Blocks the sGC/cGMP/PKG Signaling Pathway in the CUMS-Induced Rat Model

Background

Increasing evidence has shown that apoptosis in the hippocampus is closely related to depressive-like behavior. We previously reported that helicid had good antidepressant activities, which manifested as the alleviation of depression-like behaviors and the reversal of the high expression of neurocalcin delta (NCALD) in chronic unpredictable mild stress (CUMS) rats. The aim of this study was, therefore, to characterize the antidepressant-like effects and underlying mechanism of helicid on CUMS rats by silencing NCALD and using rescue experiments.

Methods

We developed the CUMS rat model using CUMS stimulation from week 0 to week 6. The rats were treated with helicid, or NCALD silenced, then we overexpressed NCALD using adeno-associated virus. We also measured the protein levels of sGCα1, sGCβ1, PKG1/2, and cleaved caspase-3 in hippocampal tissues using western blotting and measured cGMP using an ELISA.

Results

Treating CUMS rats by silencing NCALD or by the administration of helicid improved the depressive-like behavior. The levels of proteins, including sGC, PKG, cleaved caspase-3, and cGMP, in hippocampus all decreased. NCALD overexpression reversed these decreases and reversed the alleviation of depression-like behaviors in CUMS rats. Limitation. We only detected the antidepressant effects of helicid in the hippocampus; therefore, other parts of brain should also be studied.

Conclusions

Inhibition of NCALD, as well as helicid administration, alleviated antidepressant-like behavior by regulating the expressions of apoptotic cytokines and the sGC/cGMP/PKG signaling pathway. Overexpressing NCALD reversed the amelioration effects of silenced NCALD and helicid administration.