Fingolimod (FTY720) attenuates social deficits, learning and memory impairments, neuronal loss and neuroinflammation in the rat model of autism

Therapeutic effects of nanosilibinin in valproic acid-zebrafish model of autism spectrum disorder: Focusing on Wnt signaling pathway and autism spectrum disorder-related cytokines

In this study, we delved into the intricate world of autism spectrum disorder (ASD) and its connection to the disturbance in the Wnt signaling pathway and immunological abnormalities. Our aim was to evaluate the impact of silibinin, a remarkable modulator of both the Wnt signaling pathway and the immune system, on the neurobehavioral and molecular patterns observed in a zebrafish model of ASD induced by valproic acid (VPA). Because silibinin is a hydrophobic molecule and highly insoluble in water, it was used in the form of silibinin nanoparticles (nanosilibinin, NS). After assessing survival, hatching rate, and morphology of zebrafish larvae exposed to different concentrations of NS, the appropriate concentrations were chosen. Then, zebrafish embryos were exposed to VPA (1 μM) and NS (100 and 200 μM) at the same time for 120 h. Next, anxiety and inattentive behaviors and the expression of CHD8, CTNNB, GSK3beta, LRP6, TNFalpha, IL1beta, and BDNF genes were assessed 7 days post fertilization. The results indicated that higher concentrations of NS had adverse effects on survival, hatching, and morphological development. The concentrations of 100 and 200 μM of NS could ameliorate the anxiety-like behavior and learning deficit and decrease ASD-related cytokines (IL1beta and TNFalpha) in VPA-treated larvae. In addition, only 100 μM of NS prevented raising the gene expression of Wnt signaling-related factors (CHD8, CTNNB, GSK3beta, and LRP6). In conclusion, NS treatment for the first 120 h showed therapeutic effect on an autism-like phenotype probably via reducing the expression of pro-inflammatory cytokines genes and changing the expression of Wnt signaling components genes.

VPA-induced autism impairs memory ability through disturbing neural oscillatory patterns in offspring rats

Autism spectrum disorder (ASD) is a general neurodevelopmental disease characterized by unusual social communication and rigid, repetitive behavior patterns. The purpose of this study was to investigate the effects of ASD on the alteration of neural oscillatory patterns and synaptic plasticity, which commonly supported a wide range of basic and higher memory activities. Accordingly, a prenatal valproic acid (VPA) exposure rat model was established for studying autism. The behavioral experiments showed that the social orientation declined and the memory ability was significantly impaired in VPA rats, which was closely associated with the synaptic plasticity deficits. Neural oscillation is the rhythmic neuron-activity, and the pathological characteristics and neurological changes in autism may be peeped at the neural oscillatory analysis. Interestingly, neural oscillatory analysis showed that prenatal VPA exposure reduced the low-frequency power but increased high-frequency gamma (HG) power in the hippocampus CA1 area. Meanwhile, the coherence and synchronization between CA3 and CA1 were abnormally increased in the VPA group, especially in theta and HG rhythms. Furthermore, the cross-frequency coupling strength of theta-LG in the CA1 and CA3 → CA1 pathway was significantly attenuated, but the theta-HG coupling strength was increased. Additionally, prenatal VPA exposure inhibited the expression of SYP and NR2B but enhanced the expression of PSD-95 along with decreased synaptic plasticity. The neural oscillatory patterns in VPA-induced offspring were disturbed with the intensity and direction of neural information flow disordered, which are consistent with the changes in synaptic plasticity, suggesting that the decline in synaptic plasticity is the underlying mechanism.

Effects of agmatine on radial-arm maze memory performance and autistic-like behaviors in a male rat model of autism

BACKGROUND

Autism spectrum disorder (ASD) is the fastest-growing child neuropsychiatric condition. Cognitive dysfunctions such as memory impairments are experienced by patients along with social disturbances and repetitive/stereotypic movements. We have used the radial arm maze (RAM), for measurement of working and reference memory errors in an animal model of autism. In addition, the potential effects of agmatine, an endogenous NMDA antagonist, on RAM performance and autistic-like behaviors were assessed.

METHODS

Autism was modeled by valproic acid (VPA) administration at gestational Day 12.5. Autism-associated behaviors in male offspring were examined in an open field test (OFT) and three-chambered test (TCT) on postnatal days 50-51. Thereafter, the animals were trained in the RAM (PND 55) until they attained the criteria of 80% correct choices during five consecutive trials. Forty-eight hours after the acquisition of criteria, agmatine was injected 30 min before subsequent behavioral testing, which included the retention phase of the RAM, OFT, and TCT.

RESULTS

VPA-treated and intact rats showed the same performance in RAM, and acute injection of agmatine rescued social and anxiety-like behavior induced by VPA without the effect on RAM.

CONCLUSION

In a rat model of autism, spatial learning, and memory did not change. Agmatine rescued social and anxiety-like behavior in autistic animals.

Low-frequency repetitive transcranial magnetic stimulation alleviates abnormal behavior in valproic acid rat model of autism through rescuing synaptic plasticity and inhibiting neuroinflammation

Autism is a complex neurodevelopmental disorder with no effective treatment available currently. Repetitive transcranial magnetic stimulation (rTMS) is emerging as a promising neuromodulation technique to treat autism. However, the mechanism how rTMS works remains unclear, which restrict the clinical application of magnetic stimulation in the autism treatment. In this study, we investigated the effect of low-frequency rTMS on the autistic-like symptoms and explored if this neuroprotective effect was associated with synaptic plasticity and neuroinflammation in the hippocampus. A rat model of autism was established by intraperitoneal injection of valproic acid (VPA) in pregnant rats and male offspring were treated with 1 Hz rTMS daily for two weeks continuously. Behavior tests were performed to identify behavioral abnormality. Synaptic plasticity was measured by in vivo electrophysiological recording and Golgi-Cox staining. Synapse and inflammation associated proteins were detected by immunofluorescence and Western blot analyses. Results showed prenatal VPA-exposed rats exhibited autistic-like and anxiety-like behaviors, and cognitive impairment. Synaptic plasticity deficits and the abnormality expression of synapse-associated proteins were found in the hippocampus of prenatal VPA-exposed rats. Prenatal VPA exposure increased the level of inflammation cytokines and promoted the excessive activation of microglia. rTMS significantly alleviated the prenatal VPA-induced abnormalities including behavioral and synaptic plasticity deficits, and excessive neuroinflammation. TMS maybe a potential strategy for autism therapy via rescuing synaptic plasticity and inhibiting neuroinflammation.

Role of hippocampal and prefrontal cortical cholinergic transmission in combination therapy valproate and cannabidiol in memory consolidation in rats: involvement of CREB- BDNF signaling pathways

PURPOSE

Cognitive disorders are associated with valproate and drugs used to treat neuropsychological diseases. Cannabidiol (CBD) has beneficial effects on cognitive function. This study examined the effects of co-administration of CBD and valproate on memory consolidation, cholinergic transmission, and cyclic AMP response element-binding protein (CREB)-brain-derived neurotrophic factor (BDNF) signaling pathway in the prefrontal cortex (PFC) and hippocampus (HPC).

METHODS

One-trial, step-through inhibitory test was used to evaluate memory consolidation in rats. The intra-CA1 injection of physostigmine and atropine was performed to assess the role of cholinergic transmission in this co-administration. Phosphorylated CREB (p-CREB)/CREB ratio and BDNF levels in the PFC and HPC were evaluated.

RESULTS

Post-training intraperitoneal (i.p.) valproate injection reduced memory consolidation; however, post-training co-administration of CBD with valproate ameliorated memory impairment induced by valproate. Post-training intra-CA1 injection of physostigmine at the ineffective doses in memory consolidation (0.5 and 1 µg/rat), plus injection of 10 mg/kg of CBD as an ineffective dose, improved memory loss induced by valproate, which was associated with BDNF and p-CREB level enhancement in the PFC and HPC. Conversely, post-training intra-CA1 injection of ineffective doses of atropine (1 and 2 µg/rat) reduced the positive effects of injection of CBD at a dose of 20 mg/kg on valproate-induced memory loss associated with BDNF and p-CREB level reduction in the PFC and HPC.

CONCLUSION

The results indicated a beneficial interplay between valproate and CBD in the process of memory consolidation, which probably creates this interaction through the BDNF-CREB signaling pathways in the cholinergic transmission of the PFC and HPC regions.

Therapeutic Potential of Fingolimod on Psychological Symptoms and Cognitive Function in Neuropsychiatric and Neurological Disorders

Neuropsychiatric and neurological disorders pose a significant global health burden, highlighting the need for innovative therapeutic approaches. Fingolimod (FTY720), a common drug to treat multiple sclerosis, has shown promising efficacy against various neuropsychiatric and neurological disorders. Fingolimod exerts its neuroprotective effects by targeting multiple cellular and molecular processes, such as apoptosis, oxidative stress, neuroinflammation, and autophagy. By modulating Sphingosine-1-Phosphate Receptor activity, a key regulator of immune cell trafficking and neuronal function, it also affects synaptic activity and strengthens memory formation. In the hippocampus, fingolimod decreases glutamate levels and increases GABA levels, suggesting a potential role in modulating synaptic transmission and neuronal excitability. Taken together, fingolimod has emerged as a promising neuroprotective agent for neuropsychiatric and neurological disorders. Its broad spectrum of cellular and molecular effects, including the modulation of apoptosis, oxidative stress, neuroinflammation, autophagy, and synaptic plasticity, provides a comprehensive therapeutic approach for these debilitating conditions. Further research is warranted to fully elucidate the mechanisms of action of fingolimod and optimize its use in the treatment of neuropsychiatric and neurological disorders.

Supplementation with stigma maydis polysaccharide attenuates autism-like behaviors and improves gut function in valproic acid-induced autism model male rats

Stigma maydis polysaccharide (SMPS) has regulatory effect on the intestinal microflora and promotes gastrointestinal peristalsis. Children with autism spectrum disorder (ASD) often experience gastrointestinal problems and dysbiosis in their gut microbiota. Our previous study revealed that SMPS interventions had an impact on the gut microbiota of valproic acid (VPA)-induced autism model rats. However, the effects of SMPS on the behavior and gut function of autism model rats remain poorly understood. Therefore, we gave different doses of SMPS intervention in the early stage of autism model rats to observe their developmental conditions and behavior performances. Through histological evaluation and real-time polymerase chain reaction (PCR), integrity of the intestinal structure and the expression of tight junction-related gene Zo-1 and Occludin were detected. The results indicated that SMPS intervention improved the physical development, learning and memory impairment, and social performance of autism model rats. Meanwhile, SMPS promoted intestinal peristalsis and restored the integrity of the intestinal structure, reduced the number of inflammatory cells, and increased the expression of the Zo-1 and Occludin genes. Furthermore, the expression levels of neurotransmitters (substance P, enkephalin, vasoactive intestinal peptide, and 5-hydroxytryptamine) in the hippocampal tissues were altered after SMPS treatment. In conclusion, SMPS could ameliorate ASD-like phenotypes and gut problems in autism model rats. Collectively, these results provide new evidence for the relationship between the gut-brain axis and ASD and suggest a novel therapeutic target for ASD treatment.

A snapshot on introspection of autism spectrum disorder

Autism spectrum disorder is a neurodevelopmental condition marked by restricted interests and difficulty with social communication. ASD is characterized by heightened neuroinflammation and irregular neuronal connections. ASD is more frequent in male than female with male-female ratio of around 4:1. ASD affects 2.8% or 1 in 36 8-year-olds, based on the CDC's Morbidity and Mortality Weekly Report. Various factors like Environmental, Genetic, Epigenetic and Developmental factors are linked with genesis of ASD. Repetitive behaviors, Impaired communication skills, difficulty with social interaction are some of the clinical features of ASD. Current Pharmacotherapy of ASD limits to management of symptoms only, not cure. The stem cell therapy has a promising potential to be a breakthrough in treating ASD. Various types of stem cells have been successfully tested in children with ASD. AI has a potential to emerge as a tool for early detection of ASD. Robotics can assist the children with ASD to overcome the challenges associated with ASD.

Ameliorating effect of pioglitazone on prenatal valproic acid-induced behavioral and neurobiological abnormalities in autism spectrum disorder in rats

Autism spectrum disorder (ASD) is a neurodevelopment disorder that mainly arises due to abnormalities in different brain regions, resulting in behavioral deficits. Besides its diverse phenotypical features, ASD is associated with complex and varied etiology, presenting challenges in understanding its precise neuro-pathophysiology. Pioglitazone was reported to have a fundamental role in neuroprotection in various other neurological disorders. The present study aimed to investigate the therapeutic potential of pioglitazone in the prenatal valproic acid (VPA)-model of ASD in Wistar rats. Pregnant female Wistar rats received VPA on Embryonic day (E.D12.5) to induce autistic-like-behavioral and neurobiological alterations in their offspring. VPA-exposed rats presented core behavioral symptoms of ASD such as deficits in social interaction, poor spatial and learning behavior, increased anxiety, locomotory and repetitive activity, and decreased exploratory activity. Apart from these, VPA exposure also stimulated neurochemical and histopathological neurodegeneration in various brain regions. We administered three different doses of pioglitazone i.e., 2.5, 5, and 10 mg/kg in rats to assess various parameters. Of all the doses, our study highlighted that 10 mg/kg pioglitazone efficiently attenuated the autistic symptoms along with other neurochemical alterations such as oxidative stress, neuroinflammation, and apoptosis. Moreover, pioglitazone significantly attenuated the neurodegeneration by restoring the neuronal loss in the hippocampus and cerebellum. Taken together, our study suggests that pioglitazone exhibits therapeutic potential in alleviating behavioral abnormalities induced by prenatal VPA exposure in rats. However, further research is needed to fully understand and establish pioglitazone's effectiveness in treating ASD.

The emerging role of α7nAChRs/caspase-3/Nrf-2 signaling pathway in citicoline improved autistic behavior induced by thimerosal in mice

AIMS

Autism spectrum disorder (ASD) is a global concern,affecting around 75 million individuals.Various factors contribute to ASD,including mercury-containing preservatives like thimerosal (Thim) found in some vaccines.This study explored whether citicoline could be a therapeutic option for Thim-induced neuronal damage in a mouse model of ASD.Additionally,the study investigated the effects of citicoline on the α7nAChRs/Akt/Nrf2/caspase-3 pathway,which may be involved in the development of ASD.

MATERIALS AND METHODS

The study separated newborn mice into four groups.The control group received saline injections,while the Thim group received intramuscular injections of 3000 μg Hg/kg Thim on days 7,9,11,and 15 after birth.The two citicoline groups were administered Thim followed by intraperitoneal injections of 250 mg/kg or 500 mg/kg citicoline for three weeks.Afterward,various parameters were assessed, including growth,behavior,brain histopathology,oxidative stress,apoptotic,and inflammatory markers.

KEY FINDINGS

Untreated Thim-exposed mice exhibited significant brain damage,which was substantially alleviated by citicoline treatment.This beneficial effect was associated with increased expressions and concentrations of brain α7nAChRs and Akt, increased brain content of Nrf2, and the hippocampus contents of acetylcholine. Citicoline treatment decreased the brain levels of oxidative stress markers (MDA and NO),the apoptotic marker caspase-3,and pro-inflammatory markers (NF-κB,TNF-α,and IL-1β). The drug also increased the brain GPx activity.

SIGNIFICANCE

Based on the results of this study,the α7nAChRs pathway appears to be essential for the therapeutic effectiveness of citicoline in treating Thim-induced ASD in mice.

Influence of environmental enrichment on sexual behavior and the process of learning and memory in a rat model of autism with valproic acid

Autism spectrum disorder (ASD) is a psychiatric disorder with severe behavioral consequences and no specific therapy. Its etiology is multifactorial, as it is caused by a complex interaction of genetic and environmental factors. In rats, prenatal exposure to the antiepileptic drug valproic acid (VPA) has been associated with an increased risk of autistic-like behaviors in offspring, including social behavior deficits, increased repetitive behaviors, and cognitive impairments. In addition, VPA-treated rats have shown altered sociosexual behaviors. However, the mechanisms underlying these alterations in reproductive processes in VPA-treated rats are not fully understood. Interestingly some abnormal behaviors in VPA autism models are improved by an enriched environment (EE). In the present study, we examined the effects of EE on memory performance and sexual behavior in male rats. We found that on postnatal day 90, EE reduced the time it took for both control and VPA-treated groups to find a hidden platform in the Morris water maze. On PND 100, prenatal exposure to VPA reduced total exploring time in object recognition tests. On PND 110, EE reduced mount and intromission latency and increased ejaculatory frequency in VPA-treated male rats. These results suggest that environmental stimuli significantly influence the onset of sexual behavior in VPA-treated male rats and that EE may be a potential tool for improving a variety of behavioral deficiencies in rodent models of autism.

Vitamin A ameliorates valproic acid-induced autism-like symptoms in developing zebrafish larvae by attenuating oxidative stress and apoptosis

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by social deficits and repetitive/stereotyped behaviors. Prenatal exposure to valproic acid (VPA) has been reported to induce ASD-like symptoms in human and rodents. However, the etiology and pathogenesis of ASD have not been well elucidated. This study aimed to explore the mechanisms underlying VPA-induced ASD-like behaviors using zebrafish model and investigated whether vitamin A could prevent VPA-induced neurotoxicity. Here, zebrafish embryos were exposed to 0, 25 and 50 μM VPA from 4 to 96 h post fertilization (hpf) and the neurotoxicity was assessed. Our results showed that VPA affected the normal development of zebrafish larvae and induced ASD-like behaviors, including reduced locomotor activity, decreased distance near conspecifics, impaired social interaction and repetitive swimming behaviors. Exposure to VPA decreased the GFP signal in transgenic HuC:egfp zebrafish according to the negative effect of VPA on the expression of neurodevelopmental genes. In addition, VPA enhanced oxidative stress by promoting the production of reactive oxygen species (ROS) and hydrogen peroxide (H2O2) and inhibiting the activity of superoxide dismutase, then triggered apoptosis by upregulation of apoptotic genes. These adverse outcomes were mitigated by vitamin A, suggesting that vitamin A rescued VPA-induced ASD-like symptoms by inhibiting oxidative stress and apoptosis. Overall, this study identified vitamin A as a promising strategy for future therapeutic regulator of VPA-induced ASD-like behaviors.

SEW2871 reduces seizures via the sphingosine 1-phosphate receptor-1 pathway in the pentylenetetrazol and phenobarbitone kindling model of drug-refractory epilepsy

Epilepsy is a prevalent neurological disorder characterized by neuronal hypersynchronous discharge in the brain, leading to central nervous system (CNS) dysfunction. Despite the availability of anti-epileptic drugs (AEDs), resistance to AEDs is the greatest challenge in treating epilepsy. The role of sphingosine-1-phosphate-receptor 1 (S1PR1) in drug-resistant epilepsy is unexplored. This study investigated the effects of SEW2871, a potent S1PR1 agonist, on a phenobarbitone (PHB)-resistant pentylenetetrazol (PTZ)-kindled Wistar rat model. We measured the messenger ribonucleic acid (mRNA) expression of multi-drug resistance 1 (MDR1) and multi-drug resistance protein 5 (MRP5) as indicators for drug resistance. Rats received PHB + PTZ for 62 days to develop a drug-resistant epilepsy model. From day 48, SEW2871 (0.25, 0.5, 0.75 mg/kg, intraperitoneally [i.p.]) was administered for 14 days. Seizure scoring, behaviour, oxidative markers like reduced glutathione, catalase, superoxide dismutase, inflammatory markers like interleukin 1 beta tumour necrosis factor alpha, interferon gamma and mRNA expression (MDR1 and MRP5) were assessed, and histopathological assessments were conducted. SEW2871 demonstrated dose-dependent improvements in seizure scoring and neurobehavioral parameters with a reduction in oxidative and inflammation-induced neuronal damage. The S1PR1 agonist also downregulated MDR1 and MRP5 gene expression and significantly decreased the number of dark-stained pyknotic nuclei and increased cell density with neuronal rearrangement in the rat brain hippocampus. These findings suggest that SEW2871 might ameliorate epileptic symptoms by modulating drug resistance through downregulation of MDR1 and MRP5 gene expression.

Clinically approved immunomodulators ameliorate behavioral changes in a mouse model of hereditary spastic paraplegia type 11

We have previously demonstrated that neuroinflammation by the adaptive immune system acts as a robust and targetable disease amplifier in a mouse model of Spastic Paraplegia, type 11 (SPG11), a complicated form of Hereditary Spastic Paraplegia (HSP). While we identified an impact of neuroinflammation on distinct neuropathological changes and gait performance, neuropsychological features, typical and clinically highly relevant symptoms of complicated HSPs, were not addressed. Here we show that the corresponding SPG11 mouse model shows distinct behavioral abnormalities, particularly related to social behavior thus partially reflecting the neuropsychological changes in patients. We provide evidence that some behavioral abnormalities can be mitigated by genetic inactivation of the adaptive immune system. Translating this into a clinically applicable approach, we show that treatment with the established immunomodulators fingolimod or teriflunomide significantly attenuates distinct behavioral abnormalities, with the most striking effect on social behavior. This study links neuroinflammation to behavioral abnormalities in a mouse model of SPG11 and may thus pave the way for using immunomodulators as a treatment approach for SPG11 and possibly other complicated forms of HSP with neuropsychological involvement.

Three Decades of Valproate: A Current Model for Studying Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder with increased prevalence and incidence in recent decades. Its etiology remains largely unclear, but it seems to involve a strong genetic component and environmental factors that, in turn, induce epigenetic changes during embryonic and postnatal brain development. In recent decades, clinical studies have shown that inutero exposure to valproic acid (VPA), a commonly prescribed antiepileptic drug, is an environmental factor associated with an increased risk of ASD. Subsequently, prenatal VPA exposure in rodents has been established as a reliable translational model to study the pathophysiology of ASD, which has helped demonstrate neurobiological changes in rodents, non-human primates, and brain organoids from human pluripotent stem cells. This evidence supports the notion that prenatal VPA exposure is a valid and current model to replicate an idiopathic ASD-like disorder in experimental animals. This review summarizes and describes the current features reported with this animal model of autism and the main neurobiological findings and correlates that help elucidate the pathophysiology of ASD. Finally, we discuss the general framework of the VPA model in comparison to other environmental and genetic ASD models.

Anti-apoptotic capacity of MALAT1 on hippocampal neurons correlates with CASP3 DNA methylation in a mouse model of autism

Prior evidence has suggested the alleviatory effect of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on neuroinflammation in neurodegenerative diseases. This study primarily investigates the underlying mechanism of how the long non-coding RNA MALAT1 affects neuronal apoptosis in the hippocampus of mice with autism spectrum disorder (ASD). The findings demonstrate that CASP3 is highly expressed while MALAT1 is downregulated in the hippocampal neurons of autistic mice. MALAT1 mainly localizes within the cell nucleus and recruits DNA methyltransferases (including DNMT1, DNMT3a, and DNMT3b) to the promoter region of CASP3, promoting its methylation and further inhibiting its expression. In vitro experiments reveal that reducing MALAT1 expression promotes the expression of CASP3 and Bax while suppressing Bcl-2 expression, thereby enhancing cellular apoptosis. Conversely, increasing MALAT1 expression yields the opposite effect. Consequently, these results further confirm the role of MALAT1 in suppressing neuronal apoptosis in the hippocampus of mice with ASD through the regulation of CASP3 promoter methylation. Thus, this research unveils the significant roles of MALAT1 and CASP3 in the pathogenesis of ASD, offering new possibilities for future therapeutic interventions.

Knockdown and inhibition of hippocampal GPR17 attenuates lipopolysaccharide-induced cognitive impairment in mice

BACKGROUND

Previously we reported that inhibition of GPR17 prevents amyloid β 1-42 (Aβ1-42)-induced cognitive impairment in mice. However, the role of GPR17 on cognition is still largely unknown.

METHODS

Herein, we used a mouse model of cognitive impairment induced by lipopolysaccharide (LPS) to further investigate the role of GPR17 in cognition and its potential mechanism. The mice were pretreated with GPR17 shRNA lentivirus and cangrelor by microinjection into the dentate gyrus (DG) region of the hippocampus. After 21 days, LPS (0.25 mg/kg, i.p.) was administered for 7 days. Animal behavioral tests as well as pathological and biochemical assays were performed to evaluate the cognitive function in mice.

RESULTS

LPS exposure resulted in a significant increase in GPR17 expression at both protein and mRNA levels in the hippocampus. Gene reduction and pharmacological blockade of GPR17 improved cognitive impairment in both the Morris water maze and novel object recognition tests. Knockdown and inhibition of GPR17 inhibited Aβ production, decreased the expression of NF-κB p65, increased CREB phosphorylation and elevated BDNF expression, suppressed the accumulation of pro-inflammatory cytokines, inhibited Glial cells (microglia and astrocytes) activation, and increased Bcl-2, PSD-95, and SYN expression, reduced Bax expression as well as decreased caspase-3 activity and TUNEL-positive cells in the hippocampus of LPS-treated mice. Notably, knockdown and inhibition of GPR17 not only provided protective effects against cholinergic dysfunction but also facilitated the regulation of oxidative stress. In addition, cangrelor pretreatment can effectively inhibit the expression of inflammatory cytokines by suppressing NF-κB/CREB/BDNF signaling in BV-2 cells stimulated by LPS. However, activation of hippocampal GPR17 with MDL-29951 induced cognitive impairment in normal mice.

CONCLUSIONS

These observations indicate that GPR17 may possess a neuroprotective effect against LPS-induced cognition deficits, and neuroinflammation by modulation of NF-κB/CREB/BDNF signaling in mice, indicating that GPR17 may be a promising new target for the prevention and treatment of AD.

Cholesterol alterations in fragile X syndrome, autism spectrum disorders and other neurodevelopmental disorders

Neurodevelopmental disorders (NDDs) are a group of etiologically diverse diseases primarily associated with abnormal brain development, impaired cognition, and various behavioral problems. The majority of NDDs present a wide range of clinical phenotypes while sharing distinct cellular and biochemical alterations. Low plasma cholesterol levels have been reported in a subset of NNDs including, autism spectrum disorder (ASD) and fragile X syndrome (FXS). The present review focuses on cholesterol metabolism and discusses the current evidence of lipid disruption in ASD, FXS, and other genetically related NDDs. The characterization of these common deficits might provide valuable insights into their underlying physiopathology and help identify potential therapeutic targets.

Phosphodiesterase inhibitor, ibudilast alleviates core behavioral and biochemical deficits in the prenatal valproic acid exposure model of autism spectrum disorder

BACKGROUND

Autism spectrum disorder (ASD) is categorized as a neurodevelopmental disorder, presenting with a variety of aetiological and phenotypical features. Ibudilast is known to produce beneficial effects in several neurological disorders including neuropathic pain, multiple sclerosis, etc. by displaying its neuroprotective and anti-inflammatory properties. Here, in our study, the pharmacological outcome of ibudilast administration was investigated in the prenatal valproic acid (VPA)-model of ASD in Wistar rats.

METHODS

Autistic-like symptoms were induced in Wistar male pups of dams administered with Valproic acid (VPA) on embryonic day 12.5. VPA-exposed male pups were administered with two doses of ibudilast (5 and10 mg/kg) and all the groups were evaluated for behavioral parameters like social interaction, spatial memory/learning, anxiety, locomotor activity, and nociceptive threshold. Further, the possible neuroprotective effect of ibudilast was evaluated by assessing oxidative stress, neuroinflammation (IL-1β, TNF-α, IL-6, IL-10) in the hippocampus, % area of Glial fibrillary acidic protein (GFAP)-positive cells and neuronal damage in the cerebellum.

KEY FINDINGS

Treatment with ibudilast significantly attenuated prenatal VPA exposure associated social interaction and spatial learning/memory deficits, anxiety, hyperactivity, and increased nociceptive threshold, and it decreased oxidative stress markers, pro-inflammatory markers (IL-1β, TNF-α, IL-6), and % area of GFAP-positive cells and restored neuronal damage.

CONCLUSIONS

Ibudilast treatment has restored crucial ASD-related behavioural abnormalities, potentially through neuroprotection. Therefore, benefits of ibudilast administration in animal models of ASD suggest that ibudilast may have therapeutic potential in the treatment of ASD.

Effect of WiFi signal exposure in utero and early life on neurodevelopment and behaviors of rats

The aim of this study is to examine the long-term effects of prenatal and early-life WIFI signal exposure on neurodevelopment and behaviors as well as biochemical alterations of Wistar rats. On the first day of pregnancy (E0), expectant rats were allocated into two groups: the control group (n = 12) and the WiFi-exposed group (WiFi group, n = 12). WiFi group was exposed to turn on WiFi for 24 h/day from E0 to postnatal day (PND) 42. The control group was exposed to turn-off WiFi at the same time. On PND7-42, we evaluated the development and behavior of the offspring, including body weight, pain threshold, and swimming ability, spatial learning, and memory among others. Also, levels of proteins involved in apoptosis were analyzed histologically in the hippocampus in response to oxidative stress. The results showed that WiFi signal exposure in utero and early life (1) increased the body weight of WiFi + M (WiFi + male) group; (2) no change in neuro-behavioral development was observed in WiFi group; (3) increased learning and memory function in WiFi + M group; (4) enhanced comparative levels of BDNF and p-CREB proteins in the hippocampus of WiFi + M group; (5) no neuronal loss or degeneration was detected, and neuronal numbers in hippocampal CA1 were no evidently differences in each group; (6) no change in the apoptosis-related proteins (caspase-3 and Bax) levels; and (7) no difference in GSH-PX and SOD activities in the hippocampus. Prenatal WiFi exposure has no effects on hippocampal CA1 neurons, oxidative equilibrium in brain, and neurodevelopment of rats. Some effects of prenatal WiFi exposure are sex dependent. Prenatal WiFi exposure increased the body weight, improved the spatial memory and learning function, and induced behavioral hyperactivity of male rats.

Mouse nerve growth factor suppresses neuronal apoptosis in valproic acid-induced autism spectrum disorder rats by regulating the phosphoinositide-3-kinase/serine/threonine kinase signaling pathway

BACKGROUND

Autism spectrum disorder (ASD) is a group of neurodevelopmental disorders characterized by deficits in social communication and restrictive behaviors. Mouse nerve growth factor (mNGF), a neurotrophic factor, is critical for neuronal growth and survival, and the mNGF treatment is considered a promising therapy for neurodegeneration. In light of this, we aimed to evaluate the effect of mNGF on neurological function in ASD.

METHODS

An ASD rat model was established by intraperitoneal injection of valproic acid (VPA). Social behavior, learning, and memory of the rats were measured. TdT-mediated dUTP Nick-end labeling and Nissl assays were performed to detect neuronal apoptosis and survival in the hippocampus and prefrontal cortex. Apoptosis-related proteins and oxidative stress markers were detected.

RESULTS

mNGF improved locomotor activity, exploratory behavior, social interaction, and spatial learning and memory in VPA-induced ASD rats. In the hippocampus and prefrontal cortex, mNGF suppressed neuronal apoptosis, increased the number of neurons, superoxide dismutase, and glutathione levels, and decreased reactive oxygen species, nitric oxide, TNF-α, and IL-1β levels compared with the VPA group. In addition, mNGF increased the levels of Bcl-2, p-phosphoinositide-3-kinase (PI3K), and p-serine/threonine kinase (Akt), and decreased the levels of Bax and cleaved caspase-3, while the PI3K inhibitor LY294002 reversed these effects.

CONCLUSION

These data suggest that mNGF suppressed neuronal apoptosis and ameliorated the abnormal behaviors in VPA-induced ASD rats, in part, by activating the PI3K/Akt signaling pathway.

Beyond an inflammatory mediator: Interleukin-1 in neurophysiology

NEW FINDINGS

What is the topic of this review? This review focuses on the physiological role of the cytokine interleukin-1β in the CNS. What advances does it highlight? Traditionally, interleukin-1β is known as a key mediator of inflammation and immunity. This review highlights the more recent findings describing how interleukin-1β signalling is required to maintain homeostasis in the CNS.

ABSTRACT

Since its discovery in the early 1940s, the interleukin-1 (IL-1) cytokine family has been associated primarily with acute and chronic inflammation. The family member IL-1β is produced by different leucocytes, endothelial cells and epithelial cells. This cytokine has been characterized as a key modulator of inflammation and innate immunity because it induces the transcription of several downstream inflammatory genes. More recently, several groups have demonstrated that IL-1β production is also required to maintain homeostasis in several organ systems. This review focuses on providing an overview of the more recently characterized role of IL-1β in the physiology of the CNS. So far, IL-1β signalling has been implicated in neuronal survival, neurite growth, synaptic pruning, synaptic transmission, neuroplasticity and neuroendocrine functions.

G protein-coupled estrogen receptor (GPER) selective agonist G1 attenuates the neurobehavioral, molecular and biochemical alterations induced in a valproic acid rat model of autism

AIMS

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder with a rising prevalence in boys rather than girls. G protein-coupled estrogen receptor (GPER) activation by its agonist G1 showed a neuroprotective effect, similar to estradiol. The present study aimed to examine the potential of the selective GPER agonist G1 therapy on the behavioral, histopathological, biochemical, and molecular alterations induced in a valproic acid (VPA)-rat model of autism.

MAIN METHODS

VPA (500 mg/kg) was intraperitoneally administered to female Wistar rats (on gestational day 12.5) to induce the VPA-rat model of autism. The male offspring were intraperitoneally administered with G1 (10 and 20 μg/kg) for 21 days. After the treatment process, rats performed behavioral assessments. Then, sera and hippocampi were collected for biochemical and histopathological examinations and gene expression analysis.

KEY FINDINGS

GPER agonist G1 attenuated behavioral deficits, including hyperactivity, declined spatial memory and social preferences, anxiety, and repetitive behavior in VPA rats. G1 improved neurotransmission and reduced oxidative stress and histological alteration in the hippocampus. G1 reduced serum free T levels and interleukin-1β and up-regulated GPER, RORα, and aromatase gene expression levels in the hippocampus.

SIGNIFICANCE

The present study suggests that activation of GPER by its selective agonist G1 altered the derangements induced in a VPA-rat model of autism. G1 normalized free T levels via up-regulation of hippocampal RORα and aromatase gene expression. G1 provoked estradiol neuroprotective functions via up-regulation of hippocampal GPER expression. The G1 treatment and GPER activation provide a promising therapeutic approach to counteract the autistic-like symptoms.

Selection of Young Animal Models of Autism over Adult: Benefits and Limitations

Autism is a complex neurodevelopmental broad-spectrum disorder characterized by social interaction, and aberrant restrictive and repetitive behavior. The complex pathophysiology and unexplored drug targets make it difficult to standardize and validate the animal models of autism. The review was purposed for determining the benefits of younger animal models over adult models of autism. Similarly, animal models with respect to age, sex, body weight, number of animals used, along with autism inducing agents have been reviewed in this article. The differentiation of behavioral parameters has shown the benefits in the selection of younger animal models. Thus, we conclude that young and adolescence animal models of autism will be supporting for early detection and interventions with significant results.

Chronic acetyl-L-carnitine treatment alleviates behavioral deficits and neuroinflammation through enhancing microbiota derived-SCFA in valproate model of autism

Autism spectrum disorder is characterized by a variety of cellular and molecular abnormalities which leads to autism-associated behaviors. Besides behavioral defects, these individuals also suffer from various associated disorders such as gastrointestinal deficit, altered gut microbiota composition and their metabolite. This study examined the effect of ALC on microbiota SCFA production and its effects on brain inflammation in VPA autism model. After prenatal exposure to valproate (600 mg/kg, i.p.) on embryonic day 12.5, followed by ALC treatment (100 mg/kg during postnatal days 23-51, p.o.), ASD-like behaviors, SCFAs amount in feces, intestine integrity (Occludin and ZO-1 tight junction proteins), systemic and brain inflammation (TNF-α and IL-1β) were assessed. Then, Golgi-Cox staining and Western blot for Iba1 protein were utilized to identify the changes in microglia profile in cerebral cortex. In the VPA model, we found that induction of autism was associated with demoted levels of SCFAs in feces and disintegration of intestine tissue which led to elevated level of TNF-α in the plasma. Further, we characterized an increased number of microglia in our histology evaluation and Iba1 protein in cerebral cortex. We also observed elevated level of TNF-α and IL-1β in the cerebral cortex of VPA rat. All these abnormalities were significantly alleviated by ALC treatment. Overall, our findings suggest that alleviation of behavioral abnormalities by ALC therapy in the VPA model of autism is associated with an improvement in the gut microbiota SCFAs, intestinal barrier and recovery of microglia and inflammation in the brain.

Fingolimod mitigates memory loss in a mouse model of Gulf War Illness amid decreasing the activation of microglia, protein kinase R, and NFκB

Gulf War Illness (GWI) is an unrelenting multi-symptom illness with chronic central nervous system and peripheral pathology affecting veterans from the 1991 Gulf War and for which effective treatment is lacking. An increasing number of studies indicate that persistent neuroinflammation is likely the underlying cause of cognitive and mood dysfunction that affects veterans with GWI. We have previously reported that fingolimod, a drug approved for the treatment of relapsing-remitting multiple sclerosis, decreases neuroinflammation and improves cognition in a mouse model of Alzheimer's disease. In this study, we investigated the effect of fingolimod treatment on cognition and neuroinflammation in a mouse model of GWI. We exposed C57BL/6 J male mice to GWI-related chemicals pyridostigmine bromide, DEET, and permethrin, and to mild restraint stress for 28 days (GWI mice). Control mice were exposed to the chemicals' vehicle only. Starting 3 months post-exposure, half of the GWI mice and control mice were orally treated with fingolimod (1 mg/kg/day) for 1 month, and the other half were left untreated. Decreased memory on the Morris water maze test was detected in GWI mice compared to control mice and was reversed by fingolimod treatment. Immunohistochemical analysis of brain sections with antibodies to Iba1 and GFAP revealed that GWI mice had increased microglia activation in the hippocampal dentate gyrus, but no difference in reactive astrocytes was detected. The increased activation of microglia in GWI mice was decreased to the level in control mice by treatment with fingolimod. No effect of fingolimod treatment on gliosis in control mice was detected. To explore the signaling pathways by which decreased memory and increased neuroinflammation in GWI may be protected by fingolimod, we investigated the involvement of the inflammatory signaling pathways of protein kinase R (PKR) in the cerebral cortex of these mice. We found increased phosphorylation of PKR in the brain of GWI mice compared to controls, as well as increased phosphorylation of its most recognized downstream effectors: the α subunit of eukaryotic initiation factor 2 (eIF2α), IκB kinase (IKK), and the p65 subunit of nuclear factor-κB (NFκB-p65). Furthermore, we found that the increased phosphorylation level of these three proteins were suppressed in GWI mice treated with fingolimod. These results suggest that activation of PKR and NFκB signaling may be important for the regulation of cognition and neuroinflammation in the GWI condition and that fingolimod, a drug already approved for human use, may be a potential candidate for the treatment of GWI.

Fingolimod administration following hypoxia induced neonatal seizure can restore impaired long-term potentiation and memory performance in adult rats

Neonatal seizures commonly caused by hypoxia can lead to long-term neurological outcomes. Early inflammation plays an important role in the pathology of these outcomes. Therefore, in the current study, we explored the long-term effects of Fingolimod (FTY720), an analog of sphingosine and potentsphingosine 1-phosphate(S1P) receptors modulator, as an anti-inflammatory and neuroprotective agent in attenuating anxiety, memory impairment, and possible alterations in gene expression of hippocampal inhibitory and excitatory receptors following hypoxia-induced neonatal seizure (HINS). Seizure was induced in 24 male and female pups (6 in each experimental group) at postnatal day 10 (P10) by premixed gas (5% oxygen/ 95% nitrogen) in a hypoxic chamber for 15 minutes. Sixty minutes after the onset of hypoxia, FTY720 (0.3 mg/kg) or saline (100 µl) was administered for 12 days (from P10 up to P21). Anxiety-like behavior and hippocampal memory function were assessed at P90 by elevated plus maze (EPM) and novel object recognition (NOR), respectively. Long-term potentiation (LTP) was recorded from hippocampal dentate gyrus region (DG) following stimulation of perforant pathway (PP). In addition, the hippocampal concentration of superoxide dismutase activity (SOD), malondialdehyde (MDA), and thiol as indices of oxidative stress were evaluated. Finally, the gene expression of NR2A subunit of N-Methyl-D-aspartic acid (NMDA) receptor, GluR2 subunit of (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) AMPA receptor and γ2 subunit of γ-Aminobutyric acid (GABA_A) receptor were assessed at P90 by the quantitative real-time PCR. FTY720 significantly reduced later-life anxiety-like behavior, ameliorated object recognition memory and increased the amplitude and slope of the field excitatory postsynaptic potential (fEPSP) in the rats following HINS. These effects were associated with restoration of the hippocampal thiol content to the normal values and the regulatory role of FTY720 in the expression of hippocampal GABA and glutamate receptors subunits. In conclusion, FTY720 could restore the dysregulated gene expression of excitatory and inhibitory receptors. It also increased the reduced hippocampal thiol content, which was accompanied with attenuation of HINS-induced anxiety, reduced the impaired hippocampal related memory, and prevented hippocampal LTP deficits in later life following HINS.

Effects of different doses of lithium on the central nervous system in the rat valproic acid model of autism

Epidemiological studies have shown that low doses of lithium in the environment can have beneficial effects on mental health. Autism spectrum disorder, a neurodevelopmental disorder in which patients exhibit abnormal behaviors, pharmacological interventions usually relied on a range of psychotropic medications. However, such medications often produce severe side effects or are ineffective in symptoms. Finding alternative ways to improve abnormal behaviors in individuals with autism are warranted, in which case lithium may be a relatively safe and effective medication. Lithium salt therapy is used to treat a variety of neuropsychiatric disorders and has neuroprotective effects. In this study, we investigated the effects of different doses of lithium on neurobehavioural disorders using the rat model of autism established by valproic acid (VPA) injection. Lithium was observed to have an ameliorative effect on the social cognitive, social memory and anxiety levels in the rat model of autism. Immunofluorescence staining showed that subchronic LiCl administration (1.0 mmol/kg) significantly reduced the number of Iba-1 positive cells in the CA1 region of the hippocampus in VPA group and brought it close to the levels of control group. Significantly lower levels of the pro-inflammatory marker IL-6 were observed in the hippocampus and serum after lithium treatment. In addition, the lithium treatment increased the levels of H3K9 acetylation in the hippocampus of VPA-exposed rats. The results showed a defensive effect of environment-related lithium exposure doses on neurobehavioural deficits in the rat valproic acid model of autism, suggesting that it may be a potential drug for the treatment of autism.

Canagliflozin alleviates valproic acid-induced autism in rat pups: Role of PTEN/PDK/PPAR-γ signaling pathways

Autism is complex and multifactorial, and is one of the fastest growing neurodevelopmental disorders. Canagliflozin (Cana) is an antidiabetic drug that exhibits neuroprotective properties in various neurodegenerative syndromes. This study investigated the possible protective effect of Cana against the valproic acid (VPA)-induced model of autism. VPA was injected subcutaneously (SC) into rat pups at a dose of 300 mg/kg, twice daily on postnatal day-2 (PD-2) and PD-3, and once on PD-4 to induce an autism-like syndrome. Graded doses of Cana were administered (5 mg/kg, 7.5 mg/kg, and 10 mg/kg, P.O.) starting from the first day of VPA injections and continued for 21 days. At the end of the experiment, behavioral tests and histopathological alterations were assessed. In addition, the gene expression of peroxisome proliferator-activated receptor γ (PPAR γ), lactate dehydrogenase A (LDHA), pyruvate dehydrogenase kinase (PDK), cellular myeloctomatosis (c-Myc) with protein expression of glucose transporter-1 (GLUT-1), phosphatase and tensin homolog (PTEN), and level of acetylcholine (ACh) were determined. Treatment with Cana significantly counteracted histopathological changes in the cerebellum tissues of the brain induced by VPA. Cana (5 mg/kg, 7.5 mg/kg, and 10 mg/kg) improved sociability and social preference, enhanced stereotypic behaviors, and decreased hyperlocomotion activity, in addition to its significant effect on the canonical Wnt/β-catenin pathway via the downregulation of gene expression of LDHA (22%, 64%, and 73% in cerebellum tissues with 51%, 60%, and 75% in cerebrum tissues), PDK (27%, 50%, and 67% in cerebellum tissues with 34%, 66%, and 77% in cerebrum tissues), c-Myc (35%, 44%, and 72% in cerebellum tissues with 19%, 58%, and 79% in cerebrum tissues), protein expression of GLUT-1 (32%, 48%, and 49% in cerebellum tissues with 30%, 50%, and 54% in cerebrum tissues), and elevating gene expression of PPAR-γ (2, 3, and 4 folds in cerebellum tissues with 1.5, 3, and 9 folds in cerebrum tissues), protein expression of PTEN (2, 5, and 6 folds in cerebellum tissues with 6, 6, and 10 folds in cerebrum tissues), and increasing the ACh levels (4, 5, and 7 folds) in brain tissues. The current study confirmed the ameliorating effect of Cana against neurochemical and behavioral alterations in the VPA-induced model of autism in rats.

Vinpocetine, a PDE1 modulator, regulates markers of cerebral health, inflammation, and oxidative stress in a rat model of prenatal alcohol-induced experimental attention deficit hyperactivity disorder

Prenatal alcohol exposure (PAE) has been shown to induce symptomatology associated with attention deficit hyperactivity disorder (ADHD) by altering neurodevelopmental trajectories. Phosphodiesterase-1 (PDE1) is expressed centrally and has been used in various experimental brain conditions. We investigated the role of vinpocetine, a PDE1 inhibitor, on behavioral phenotypes and important biochemical deficits associated with a PAE rat model of ADHD. Protein markers of cerebral health (synapsin-IIa, BDNF, and pCREB), inflammation (IL-6, IL-10, and TNF-α), and oxidative stress (TBARS, GSH, and SOD) were analyzed in three brain regions (frontal cortex, striatum, and cerebellum). Hyperactivity, inattention, and anxiety introduced in the offspring due to PAE were assayed using open-field, Y-maze, and elevated plus maze, respectively. Administration of vinpocetine (10 & 20 mg/kg, p.o. [by mouth]) to PAE rat offspring for 4 weeks resulted in improvement of the behavioral profile of the animals. Additionally, levels of protein markers such as synapsin-IIa, BDNF, pCREB, IL-10, SOD, and GSH were found to be significantly increased, with a significant reduction in markers such as TNF-α, IL-6, and TBARS in selected brain regions of vinpocetine-treated animals. Vinpocetine, a selective PDE1 inhibitor, rectified behavioral phenotypes associated with ADHD, possibly by improving cerebral function, reducing brain inflammation, and reducing brain oxidative stress. This study provides preliminary analysis and suggests that the PDE1 enzyme may be an important pharmacological tool to study ADHD as a result of PAE.

Continuous Exposure to Alpha-Glycosyl Isoquercitrin from Gestation Ameliorates Disrupted Hippocampal Neurogenesis in Rats Induced by Gestational Injection of Valproic Acid

This study examined the ameliorating effect of alpha-glycosyl isoquercitrin (AGIQ), an antioxidant, on disrupted hippocampal neurogenesis in the dentate gyrus (DG) in a rat model of autism spectrum disorder induced by prenatal valproic acid (VPA) exposure. Dams were intraperitoneally injected with 500 mg/kg VPA on gestational day 12. AGIQ was administered in the diet at 0.25 or 0.5% to dams from gestational day 13 until weaning at postnatal day (PND) 21 and then to pups until PND 63. At PND 21, VPA-exposed offspring showed decreased numbers of type-2a and type-3 neural progenitor cells (NPCs) among granule cell lineage subpopulations. AGIQ treatment at both doses rescued the reduction in type-3 NPCs. AGIQ upregulated Reln and Vldlr transcript levels in the DG at 0.5% and ≥ 0.25%, respectively, and increased the number of reelin⁺ interneurons in the DG hilus at 0.5%. AGIQ at 0.25% and/or 0.5% also upregulated Ntrk2, Cntf, Igf1, and Chrnb2. At PND 63, there were no changes in the granule cell lineage subpopulations in response to VPA or AGIQ. AGIQ at 0.25% increased the number of FOS⁺ granule cells, accompanied by Gria2 and Gria3 upregulation and increasing trend in the number of FOS⁺ granule cells at 0.5%. There was no definitive evidence of VPA-induced oxidative stress in the hippocampus throughout postnatal life. These results indicate that AGIQ ameliorates the VPA-induced disruption of hippocampal neurogenesis at weaning involving reelin, BDNF-TrkB, CNTF, and IGF1 signaling, and enhances FOS-mediated synaptic plasticity in adulthood, potentially through AMPA-receptor upregulation. The ameliorating effects of AGIQ may involve direct interactions with neural signaling cascades rather than antioxidant capacity.

Protective Effect of Nimodipine Against Valproic-acid Induced Biochemical and Behavioral Phenotypes of Autism

OBJECTIVE

Present study was designed to investigate behavioral and biochemical role of nimodipine in prenatal valproic acid (Pre-VPA) induced autism in rats.

METHODS

Valproic acid was utilized to induce autistic phenotypes in Wistar rats. The rats were assessed for social behavior. Hippocampus and prefrontal cortex (PFC) were utilized for various biochemical assessments, whereas cerebellum was used to assess blood brain barrier (BBB) permeability.

RESULTS

Pre-VPA rats showed reduction social interaction. Pre-VPA administration were decreased PFC levels of interleukin- 10 (IL-10), and glutathione along with hippocampus cAMP response element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF). Also, the animals have shown increase in PFC levels of IL-6, tumor necrosis factor-α, thiobarbituric acid reactive substance, Evans blue leakage and water content. Nimodipine countered Pre-VPA administered reduction in social interaction, CREB, BDNF, inflammation, oxidative stress, BBB permeability.

CONCLUSION

Pre-VPA has induced autistic phenotype, which were attenuated by nimodipine in rats. Nimodipine and other calcium channel blockers should further investigate to check the management of autism.

Homotaurine ameriolates the core ASD symptomatology in VPA rats through GABAergic signalling: Role of GAD67

Dysregulated GABAergic signaling is reported in Autism Spectrum disorder (ASD). In the present study, we evaluated a GABA structural mimicker homotaurine (HT) via in-silico docking and investigated the therapeutic efficacy of this drug to ameliorate ASD symptoms in the valproic acid (VPA) rat model of ASD. For the in-vivo study, animals were divided into two groups [Normal control (NC, 0.9% saline; i.p) and disease control (VPA 600mg/kg; i.p)] on gestational day (GD) 12.5. Male pups from VPA-exposed mothers were further divided into five groups (n=6 in each group): disease control (DC, no-further treatment), standard treatment (risperidone (RES) 2.5mg/kg; i.p, consecutively from PND 23-43), HT (10, 25 and 50mg/kg; i.p, consecutively from PND 23-43). In in-silico studies, the binding pattern of homotaurine to GABA-A receptor was found similar to GABA with Tyr205, Glu155, Tyr157, Arg6, and Thr 130 as shared residues. In the in-vivo phase, the early developmental parameters (from PND 7-23) and behavioral parameters (from PND 43-54) were assessed. The offspring of the VPA exposed group exhibited significant (p<0.05) developmental delays, behavioral deficits [decreased sociability and social novelty (three-chamber sociability test), spatial memory (Morris water maze), increased stereotypy (self-grooming)], increased oxidative stress (decreased GSH, SOD, Catalase, and increased MDA), increased pro-inflammatory (IL-1β, 6, TNF-α) and decreased anti-inflammatory (IL-10) cytokines, Purkinje cell loss in the cerebellum and pyknosis in PFC (H/E, Nissil staining) and decreased GAD67 expression in the cerebellum (RT-PCR & immunohistochemistry). Compared to the DC, HT treatment (50mg/kg) was able to ameliorate the aberrant core behavioral deficits, decreased oxidative stress, decreased pro-inflammatory and increased anti-inflammatory cytokine profile with preservation of the Purkinje cell density in the cerebellum, decreased pyknosis in the prefrontal cortex and normalised the expression of GAD67. Thus, HT can be a useful therapeutic agent in ASD and requires further clinical evaluation.

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.

PI3K/AKT/mTOR signalling inhibitor chrysophanol ameliorates neurobehavioural and neurochemical defects in propionic acid-induced experimental model of autism in adult rats

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder marked by social and communication deficits as well as repetitive behaviour. Several studies have found that overactivation of the PI3K/AKT/mTOR signalling pathways during brain development plays a significant role in autism pathogenesis. Overexpression of the PI3K/AKT/mTOR signalling pathway causes neurological disorders by increasing cell death, neuroinflammation, and oxidative stress. Chrysophanol, also known as chrysophanic acid, is a naturally occurring chemical obtained from the plant Rheum palmatum. This study aimed to examine the neuroprotective effect of CPH on neurobehavioral, molecular, neurochemical, and gross pathological alterations in ICV-PPA induced experimental model of autism in adult rats. The effects of ICV-PPA on PI3K/AKT/mTOR downregulation in the brain were studied in autism-like rats. Furthermore, we investigated how CPH affected myelin basic protein (MBP) levels in rat brain homogenate and apoptotic biomarkers such as caspase-3, Bax, and Bcl-2 levels in rat brain homogenate and blood plasma samples. Rats were tested for behavioural abnormalities such as neuromuscular dysfunction using an actophotometer, motor coordination using a beam crossing task (BCT), depressive behaviour using a forced swim test (FST), cognitive deficiency, and memory consolidation using a Morris water maze (MWM) task. In PPA-treated rats, prolonged oral CPH administration from day 12 to day 44 of the experimental schedule reduces autistic-like symptoms. Furthermore, in rat brain homogenates, blood plasma, and CSF samples, cellular, molecular, and cell death markers, neuroinflammatory cytokines, neurotransmitter levels, and oxidative stress indicators were investigated. The recent findings imply that CPH also restores abnormal neurochemical levels and may prevent autism-like gross pathological alterations, such as demyelination volume, in the rat brain.

TCHis mitigate oxidative stress and improve abnormal behavior in a prenatal valproic acid-exposed rat model of autism

Objective Troxerutin is known for its anti-inflammatory and antioxidative effects in nerve impairment. The purpose of this study is to investigate the effect of troxerutin and cerebroprotein hydrolysate injections (TCHis) on prenatal valproic acid (VPA)-exposed rats. Methods The VPA was administered to pregnant rats on gestational day 12.5 to induce a model of autism. The offsprings were given the treatment of TCHis on postnatal day (PND) 21-50. On PND 43-50, the behavioral analysis of offsprings was performed after the treatment of TCHis for 1 h. On PND 50, the offsprings were harvested and the brains were collected. The hippocampus and prefrontal cortex were isolated for relevant biochemical detections. Results The administration of TCHis increased the pain sensitivity and improved abnormal social behaviors in prenatal VPA-exposed rats. Prenatal expose of VPA induced neuronal loss and apoptosis, enhanced reactive oxygen species (ROS) production, and promoted oxidative stress in hippocampus and prefrontal cortex, while these effects were reversed by the postnatal treatment of TCHis. In addition, postnatal administration of TCHis ameliorated mitochondrial function in hippocampus and prefrontal cortex of prenatal VPA-exposed rats. Conclusion This study concluded that postnatal treatment of TCHis reduced oxidative stress and ameliorated abnormal behavior in a prenatal VPA-induced rat model of autism.

Pharmacological Activation of GPR55 Improved Cognitive Impairment Induced by Lipopolysaccharide in Mice

Our previous research found that activation of GPR55 can alleviate cognitive impairment induced by amyloid-beta 1-42 (Aβ_1-42) and streptozotocin in mice, but the role of GPR55 in the pathogenesis of cognitive impairment remains unknown. Here, we used a lipopolysaccharide (LPS) mouse model to further investigate the role and mechanism of O-1602, a GPR55 agonist, on cognitive dysfunction. ICR mice were treated with an intracerebroventricular (i.c.v.) injection of LPS, followed by cognitive function tests. The expression of GPR55, NF-κB p65, caspase-3, Bax, and Bcl-2 in the hippocampus was examined by Western blotting. Inflammatory cytokines and microglia were detected by ELISA kit and immunohistochemical analyses, respectively. The levels of MDA, GSH, SOD, and CAT were examined by assay kits. Furthermore, TUNEL-staining was used to detect neuronal apoptosis. Our results showed that i.c.v. injection of LPS in mice exhibited impaired performance in the behavior tests, which were ameliorated by O-1602 treatment (2.0 or 4.0 μg/mouse, i.c.v.). Importantly, we found that O-1602 treatment reversed GPR55 downregulation, decreased the expression of NF-κB p65, suppressed the accumulation of proinflammatory cytokines and microglia activation, increased the anti-inflammatory cytokines, and reduced the levels of MDA, increased the levels of GSH, SOD, and CAT in the hippocampus. In addition, O-1602 treatment also significantly reduced Bax and increased Bcl-2 expression as well as decreased caspase-3 activity and TUNEL-positive cells in the hippocampus. These observations indicate that O-1602 may ameliorate LPS-induced cognition deficits via inhibiting neuroinflammation, oxidative stress, and apoptosis mediated by the NF-κB pathway in mice.

Sumac and gallic acid-loaded nanophytosomes ameliorate hippocampal oxidative stress via regulation of Nrf2/Keap1 pathway in autistic rats

Autism spectrum disorders cover a range of neurodevelopmental disorders characterized by impairments in social interaction and cognitive deficits. Phenolic compound applications have been restricted due to their poor solubility, bioavailability, and low stability. This paper aimed to explore the neuroprotective effects of sumac and gallic acid-loaded nanophytosomes (GNP) on oxidative stress-induced cognitive impairment and Nrf2/Keap1 gene expression in the autism model. Valproic acid (VPA) was administered intraperitoneally at doses of 500 mg/kg to female rats during gestational 12.5 days (E12.5). The prenatal VPA-exposed rats were divided into five groups, including VPA, VPA treated with sumac, gallic acid (GA), sumac-loaded nanophytosome (SNP), and GNP at doses of 20 mg/kg for 4 weeks (n = 6). A novel object test was conducted and antioxidant parameters and Nrf2/Keap1gene expression were evaluated in the hippocampus. According to the obtained results, the rat model of autism exhibited recognition memory impairment. We observed an increase in glutathione peroxidase (GPx), glutathione reductase (GRx), superoxide dismutase (SOD), catalase (CAT) enzyme activity, total antioxidant capacity (TAC), and glutathione (GSH) levels. Furthermore, sumac and GNP improved recognition memory deficits and increased GPx, GRx, SOD, and CAT activities, GSH and TAC levels, and Nrf2/Keap1gene expression in the hippocampal area. Our results also suggested that SNP and GNP ameliorate VPA-induced learning and memory deficits more efficiently than sumac extract and pure GA by reducing oxidative stress, enhancing antioxidant enzyme activity, and Keap1/Nrf2 gene expression. The present study demonstrated that the utilization of SNP and GNP significantly improved recognition memory deficits.

Brain Cholesterol Biosynthetic Pathway Is Altered in a Preclinical Model of Fragile X Syndrome

Fragile X Syndrome (FXS) is the most frequent form of inherited X-linked pathology, associated with an intellectual and developmental disability, and currently considered the first monogenic cause of autism spectrum disorder (ASD). Low levels of total cholesterol reported in the serum of FXS patients, and evidence that FMRP targets a subset of mRNAs encoding proteins of lipid synthesis and transport suggests that the cholesterol metabolism impairments could be involved in FXS. Thus, the aim of the presented work was to investigate the modulations of the cholesterol biosynthetic pathway and its end-products in a recently developed Fmr1-Δexon 8 rat model of FXS. Here, we show that this experimental model mimics what is found in FXS patients, exhibiting a lower serum cholesterol content, accompanied by a reduction in food intake and body weight compared to WT animals. Moreover, alterations of proteins committed to cholesterol synthesis and uptake have been observed in the amygdala, prefrontal cortex and nucleus accumbens. Interestingly, the end-products show a brain region-dependent modulation in Fmr1-Δexon 8 rats. Overall, our results demonstrate that the cholesterol biosynthetic pathway is altered in some brain regions of this preclinical model of FXS. This finding has relevance for future studies to delve deeper into the involvement of this metabolic process in FXS, and thus its possible role as a therapeutic target.

Vesicle Fusion as a Target Process for the Action of Sphingosine and Its Derived Drugs

The fusion of membranes is a central part of the physiological processes involving the intracellular transport and maturation of vesicles and the final release of their contents, such as neurotransmitters and hormones, by exocytosis. Traditionally, in this process, proteins, such SNAREs have been considered the essential components of the fusion molecular machinery, while lipids have been seen as merely structural elements. Nevertheless, sphingosine, an intracellular signalling lipid, greatly increases the release of neurotransmitters in neuronal and neuroendocrine cells, affecting the exocytotic fusion mode through the direct interaction with SNAREs. Moreover, recent studies suggest that FTY-720 (Fingolimod), a sphingosine structural analogue used in the treatment of multiple sclerosis, simulates sphingosine in the promotion of exocytosis. Furthermore, this drug also induces the intracellular fusion of organelles such as dense vesicles and mitochondria causing cell death in neuroendocrine cells. Therefore, the effect of sphingosine and synthetic derivatives on the heterologous and homologous fusion of organelles can be considered as a new mechanism of action of sphingolipids influencing important physiological processes, which could underlie therapeutic uses of sphingosine derived lipids in the treatment of neurodegenerative disorders and cancers of neuronal origin such neuroblastoma.

Activation of GPR55 attenuates cognitive impairment and neurotoxicity in a mouse model of Alzheimer's disease induced by Aβ1-42 through inhibiting RhoA/ROCK2 pathway

The accumulation of amyloid-β (Aβ) peptides in the brain is considered to be the initial event in the Alzheimer's disease (AD). Neurotoxicity mediated by Aβ has been demonstrated to damage the cognitive function. In the present study, we sought to determine the effects of O-1602, a specific G-protein coupled receptor 55 (GPR55) agonist, on the impairment of learning and memory induced by intracerebroventricular (i.c.v.) of Aβ_1-42 (400 pmol/mouse) in mice. Our results showed that i.c.v. injection of aggregated Aβ_1-42 into the brain of mice resulted in cognitive impairment and neurotoxicity. In contrast, O-1602 (2.0 or 4.0 μg/mouse, i.c.v.) can improve memory impairment induced by Aβ_1-42 in the Morris water maze (MWM), and novel object recognition (NOR) tests. Besides, we found that O-1602 reduced the activity of β-secretase 1 (BACE1) and the level of soluble Aβ_1-42 in the hippocampus and frontal cortex. Importantly, O-1602 treatment reversed Aβ_1-42-induced GPR55 down-regulation, decreased pro-inflammatory cytokines, and the level of malondialdehyde (MDA), increased the levels of glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT), as well as suppressed apoptosis as indicated by decreased TUNEL-positive cells, and increased the ratio of Bcl-2/Bax. O-1602 treatment also pronouncedly ameliorated synaptic dysfunction by promoting the upregulation of PSD-95 and synaptophysin (SYN) proteins. Moreover, O-1602 concurrently down regulated the protein levels of RhoA, and ROCK2, the critical proteins in the RhoA/ROCK2 pathway. This study indicates that O-1602 may reverse Aβ_1-42-induced cognitive impairment and neurotoxicity in mice by inhibiting RhoA/ROCK2 pathway. Taken together, these findings suggest that GPR55 could be a novel and promising target for the treatment of AD.

Influence of Prenatal Drug Exposure, Maternal Inflammation, and Parental Aging on the Development of Autism Spectrum Disorder

Autism spectrum disorder (ASD) affects reciprocal social interaction and produces abnormal repetitive, restrictive behaviors and interests. The diverse causes of ASD are divided into genetic alterations and environmental risks. The prevalence of ASD has been rising for several decades, which might be related to environmental risks as it is difficult to consider that the prevalence of genetic disorders related to ASD would increase suddenly. The latter includes (1) exposure to medications, such as valproic acid (VPA) and selective serotonin reuptake inhibitors (SSRIs) (2), maternal complications during pregnancy, including infection and hypertensive disorders of pregnancy, and (3) high parental age. Epidemiological studies have indicated a pathogenetic role of prenatal exposure to VPA and maternal inflammation in the development of ASD. VPA is considered to exert its deleterious effects on the fetal brain through several distinct mechanisms, such as alterations of γ-aminobutyric acid signaling, the inhibition of histone deacetylase, the disruption of folic acid metabolism, and the activation of mammalian target of rapamycin. Maternal inflammation that is caused by different stimuli converges on a higher load of proinflammatory cytokines in the fetal brain. Rodent models of maternal exposure to SSRIs generate ASD-like behavior in offspring, but clinical correlations with these preclinical findings are inconclusive. Hypertensive disorders of pregnancy and advanced parental age increase the risk of ASD in humans, but the mechanisms have been poorly investigated in animal models. Evidence of the mechanisms by which environmental factors are related to ASD is discussed, which may contribute to the development of preventive and therapeutic interventions for ASD.

Environmental enrichment and intranasal oxytocin administration reverse maternal separation-induced impairments of prosocial choice behavior

Adverse early life experiences influence behavioral and physiological functions and increase vulnerability to neuropsychiatric disorders. Maternal separation (MS) is an established animal model that reproduces the features of chronic stress or adverse experiences during early life. Previous studies have been shown that MS may lead to impairments of social behaviors. Here, we investigated the effects of MS on mutual reward preferences in a double T-maze prosocial choice task. Since enriched environment (EE) and intranasal oxytocin (OT) administration have beneficial effects on cognition and social behaviors, in the present study we tested whether these treatments, alone or in combination, would affect prosocial behavior of rats which underwent MS during infancy. Rat pups underwent MS paradigm for 180 min/day from postnatal day (PND) 1-21. From PND 22-34, rats were exposed to an EE and/or received intranasal OT (2 μg/μl, 7 days). Hence, the 8 groups consisted of control (CTRL), MS, CTRL+EE, CTRL+OT and the saline groups. Assessment of prosocial choice behavior was started in adolescence. MS impaired prosocial choice behavior and reduced mutual reward preferences. Getting exposed to EE and intranasal OT administration could overcome MS-induced deficits and promoted mutual reward preferences of MS rats. Combination of short-term EE and OT strengthened prosocial behavior. Obtained results showed that EE and OT may be considered as profitable therapeutic approaches for promoting some aspects of social behavior.

Effects of short environmental enrichment on early-life adversity induced cognitive alternations in adolescent rats

Early-life experiences, including parental care, affect cognitive performance later in life. Being exposed to early-life maternal separation (MS) increases susceptibility to stress-related psychopathology. Previous studies suggest that MS could induce learning and memory impairments. Since enriched environment (EE) provides more opportunities for exploration and social interaction, in the present study we evaluated the effects of a short EE paradigm with a duration of 13 days on cognitive abilities of maternally separated rats (MS; 180 min/day, postnatal day (PND) 1-21) during adolescence in four experimental groups: Control, Control+EE, MS, and MS+EE. Plasma corticosterone (CORT) and brain-derived neurotrophic factor (BDNF) levels were also measured in experimental animals. We also studied the induction of long-term potentiation (LTP) in the slices of hippocampal CA1 area. The behavioral and electrophysiological assessments were started at PND 35. MS caused higher basal CORT levels in plasma and impaired spatial learning, memory, and social interaction. LTP induction was also impaired in MS rats and plasma BDNF levels were reduced in these animals. MS also induced more anxiety-like behavior. Short EE reduced plasma CORT levels had the potential to improve locomotor activity and anxiety-like behavior in MS+EE rats and reversed MS-induced impairments of spatial learning, memory, and social behavior. LTP induction and plasma BDNF levels were also enhanced in MS+EE rats. We concluded that short EE might be considered as a therapeutic strategy for promoting cognition.

Neuroprotective Effects of Fingolimod in a Cellular Model of Optic Neuritis

Visual dysfunction resulting from optic neuritis (ON) is one of the most common clinical manifestations of multiple sclerosis (MS), characterized by loss of retinal ganglion cells, thinning of the nerve fiber layer, and inflammation to the optic nerve. Current treatments available for ON or MS are only partially effective, specifically target the inflammatory phase, and have limited effects on long-term disability. Fingolimod (FTY) is an FDA-approved immunomodulatory agent for MS therapy. The objective of the current study was to evaluate the neuroprotective properties of FTY in the cellular model of ON-associated neuronal damage. R28 retinal neuronal cell damage was induced through treatment with tumor necrosis factor-α (TNFα). In our cell viability analysis, FTY treatment showed significantly reduced TNFα-induced neuronal death. Treatment with FTY attenuated the TNFα-induced changes in cell survival and cell stress signaling molecules. Furthermore, immunofluorescence studies performed using various markers indicated that FTY treatment protects the R28 cells against the TNFα-induced neurodegenerative changes by suppressing reactive oxygen species generation and promoting the expression of neuronal markers. In conclusion, our study suggests neuroprotective effects of FTY in an in vitro model of optic neuritis.

Cilostazol attenuated prenatal valproic acid-induced behavioural and biochemical deficits in a rat model of autism spectrum disorder

OBJECTIVES

Autism spectrum disorder (ASD) is categorized as a neurodevelopmental disorder, presenting with a variety of aetiological and phenotypical features. Inhibiting the enzyme phosphodiesterase-3 (PDE3) with cilostazol is known to produce beneficial effects in several brain disorders. The pharmacological outcome of cilostazol administration was investigated in prenatal valproic acid (VPA)-induced ASD deficits in albino Wistar rats.

METHODS

Cilostazol was administered in two doses (30/60 mg/kg) to male rats born of females administered with VPA on gestational day 12. Behavioural assays on locomotion (open field), social interaction, repetitive behaviour (y-maze) and anxiety (elevated plus maze) were performed in all groups. Further, biochemical assessments of markers associated with neuronal function (BDNF, pCREB), inflammation (TNF-α, IL-6, IL-10) and oxidative stress were carried out in frontal cortex, hippocampus, striatum and cerebellum.

KEY FINDINGS

The cilostazol regimen, attenuated prenatal VPA exposure associated hyperlocomotion, social interaction deficits, repetitive behavior, and anxiety. Further, biochemical markers such as BDNF, pCREB, IL-10 and GSH were found to be significantly increased contrary to markers such as TNF-α, IL-6 and TBARS in the assessed brain regions.

CONCLUSIONS

Cilostazol rectified core behavioural traits while producing significant changes to biochemistry in the brain, suggesting benefits of cilostazol administration in experimental models of ASD.

Increased prevalence of attention-deficit hyperactivity disorder symptomatology in patients with familial Mediterranean fever

OBJECTIVES

Previous studies suggest that exposure to inflammation in infancy may increase the risk for attention-deficit and hyperactivity disorder (ADHD). We studied the ADHD manifestations among 124 familial Mediterranean fever (FMF) patients and examined the relationship between FMF patient characteristics and ADHD.

METHODS

Clinical, demographic, and genetic data were abstracted from patients' medical records and supplemented by information obtained during clinic visits. ADHD manifestations were assessed using the Diagnostic and Statistical Manual of Mental Disorders (5th ed.) questionnaire.

RESULTS

ADHD was diagnosed in 42 (32.8%) FMF patients, a rate significantly higher than in unselected populations (∼8%). A majority (n = 27, 64.3%) had combined inattentive, hyperactive-impulsive manifestations. Eight (19%) had predominantly hyperactive-impulsive, and seven (16.6%) had predominantly inattentive symptoms. FMF patients with severe manifestations reported more ADHD symptoms. FMF patients with ADHD symptoms were less adherent to their treatment regimen, with only 61.9% of the patients with ADHD symptoms adhering to colchicine therapy compared to 92.7% of the patients without ADHD symptoms.

CONCLUSION

The high prevalence of ADHD characteristics in children with FMF may support the neuroimmune hypothesis that chronic inflammation increases the risk for ADHD. Children with FMF should be screened for ADHD as its presence may adversely affect adherence to treatment.