Rotarod Assay Research Articles

Transdermal Delivery of Botulinum Neurotoxin A: A Novel Formulation with Therapeutic Potential

Background: Botulinum neurotoxin is widely regarded as a “wonder medicine” due to its therapeutic efficacy in treating a variety of conditions. While it is traditionally classified as a neurotoxin, it is arguably more appropriate to refer to it as a neuromedicine. All FDA-approved formulations of botulinum neurotoxin are currently administered through intramuscular injections, with no other delivery methods widely used. The primary reasons for this include the following: (a) the extremely high potency of the toxin, (b) the potential for diffusion to adjacent muscles, (c) factors related to the site of administration (e.g., muscle thickness), (d) the large size of the molecule, (e) the impermeability of skin to large protein molecules, and (f) safety concerns. Despite these challenges, there is growing interest in the development of an effective transdermal formulation of botulinum neurotoxin. Refining and standardizing the delivery technology for topical or transdermal use remains an important goal for the future. Methods: The aim of this study was to develop a nanoemulsion-based transdermal formulation capable of delivering active botulinum neurotoxin (BoNT) through human skin. The goal was to demonstrate its efficacy in a mouse model, highlighting the therapeutic effects on both neuromuscular activity and hyperhidrosis. We successfully developed a nanoemulsion-based formulation that facilitates the transdermal delivery of BoNT. The formulation was homogeneous, stable, and efficacious. In a mouse model, we evaluated the neurotoxin’s impact on neuromuscular function using the Digital Abduction Score (DAS) for toe-spread and rota-rod assay to assess motor coordination. Results: The results confirmed the successful paralytic effect of the neuotoxin. The formulation significantly reduced sweating in the hyperhidrosis mouse model, indicating the therapeutic potential for this indication. Beyond the neurotoxin’s paralyzing effect, we also observed the recovery of nerve function, showing that the neurotoxin does not cause permanent damage, further underscoring its safety and efficacy. Conclusions: This formulation is the first of its kind to successfully deliver a large biomolecule like BoNT across the skin and produce a therapeutic effect. The ability to deliver large biomolecules transdermally has the potential to serve as a platform technology for treating a variety of conditions, including neuromuscular disorders, skin conditions, and localized pain management.

Hematopoietic stem cell gene therapy for the treatment of SYNGAP1-related non-specific intellectual disability.

Synaptic Ras GTPase activating protein 1 (SYNGAP1)-related non-specific intellectual disability is a neurodevelopmental disorder caused by an insufficient level of SynGAP1 resulting in a dysfunction of neuronal synapses and presenting with a wide array of clinical phenotypes. Hematopoietic stem cell gene therapy has the potential to deliver therapeutic levels of functional SynGAP1 to affected neurons upon transduction of hematopoietic stem and progenitor cells with a lentiviral vector. As a novel approach toward the treatment of SYNGAP1, we have generated a lentiviral vector expressing a modified form of SynGAP1 for transduction of human CD34+ hematopoietic stem and progenitor cells. The gene-modified cells were then transplanted into adult immunodeficient SYNGAP1+/- heterozygous mice and evaluated for improvement of SYNGAP1-related clinical phenotypes. Expression of SynGAP1 was also evaluated in the brain tissue of transplanted mice. In our proof-of-concept study, we have demonstrated significant improvement of SYNGAP1-related phenotypes including an improvement in motor abilities observed in mice transplanted with the vector transduced cells because they displayed decreased hyperactivity in an open field assay and an increased latency to fall in a rotarod assay. An increased level of SynGAP1 was also detected in the brains of these mice. These early-stage results highlight the potential of this stem cell gene therapy approach as a treatment strategy for SYNGAP1.

Viral-mediated inflammation by Poly I:C induces the chemokine CCL5 in NK cells and its receptors CCR1 and CCR5 in microglia in the neonatal rat cerebellum.

To study the effect of viral inflammation induced by Polyinosinic:polycytidylic acid (PIC) on the cerebellum during a critical period of development in rats. Neonatal rat pups were treated with PIC on postnatal days (PN) 8 and 10 after which we quantified RNA using Nanostring, qRT-PCR and RNAscope and analyzed immune cells through flow cytometry and immunohistochemistry on PN11. Using the same paradigm, we also analyzed play juvenile behavior, anxiety-like behavior, motor balance using the balance beam and the rotarod assays as well as fine motor behavior using the sunflower seed opening test. We determined that male and female pups treated with PIC reacted with a significant increase in CCL5, a chemotactic cytokine that attracts T-cells, eosinophils and basophils to the site of inflammation, at PN11. PIC treatment also increased the expression of two receptors for CCL5, CCR1 and CCR5 in the cerebellar vermis in both males and females at PN11. In-situ hybridization (RNAscope®) for specific transcripts revealed that microglia express both CCL5 receptors under inflammatory and non-inflammatory conditions in both males and females. PIC treatment also increased the total number of CCL5+ cells in the developing cerebellum which were determined to be both natural killer cells and T-cells. There were modest but significant impacts of PIC treatment on large and fine motor skills and juvenile play behavior. Our findings suggest an important role for CCL5 and other immune cells in mediating inflammation in the developing cerebellum that potentially impact the maturation of cerebellar neurons during a critical period of development.

Oxyberberine protects middle cerebral artery occlusion triggered cerebral injury through TLR4/NLRP3 pathway in rats

Cerebral ischemia is a life-threatening health concern that leads to severe neurological complications and fatalities worldwide. Although timely intervention with clot-removing agents curtails serious post-stroke neurological dysfunctions, no effective neuroprotective intervention is available for addressing post-recanalization neuroinflammation. Herein, for the first time we studied the effect of oxyberberine (OBB), a derivative of berberine, on transient middle cerebral artery occlusion (MCAO)-generated neurological consequences in Sprague-Dawley rats. The MCAO-operated rats exhibited significant somatosensory and sensorimotor dysfunctions in adhesive removal, foot fault, paw whisker, and rotarod assays at 1 and 3 days post-surgery. These MCAO-generated neurological deficits were prevented in OBB-treated (50 and 100mg/kg) rats, and also coincided with a smaller infarct area (in 2,3,5-triphenyl tetrazolium chloride staining) and decreased neuronal death (in cresyl violet staining) in the ipsilateral hemisphere of these animals. The immunostaining of neuronal nuclear protein (NeuN) and glial-fibrillary acidic protein (GFAP) also echoes the neuroprotective nature of OBB. The increased expression of neuroinflammatory and blood-brain barrier tight junction proteins like toll-like receptor 4 (TLR4), TRAF-6, nuclear factor kappa B (NF-κB), pNF-κB, nNOS, ASC, and IKBα in the ipsilateral part of MCAO-operated rats were restored to normal following OBB treatment. We also observed the decline in plasma levels/mRNA transcription of TNF-α, IL-1β, NLRP3, IL-6, and matrix metalloproteinase-9 and increased expression of occludin and claudin in OBB-treated rats. These outcomes imply that OBB may prevent the MCAO-induced neurological consequences and neuroinflammation by interfering with TLR4 and NLRP3 signaling in rats.

Oxyberberine an oxoderivative of berberine confers neuroprotective effects in controlled-cortical impact mouse model of traumatic brain injury

Background Traumatic brain injury (TBI) is known as a silent epidemic that causes many deaths and disabilities worldwide. We examined the response of oxyberberine (OBB) in lipopolysaccharide-stimulated BV2 microglial cells and a controlled-cortical impact (CCI) mouse model of TBI. Methods We synthesized OBB from berberine, and also prepared OBB-nanocrystals (OBB-NC). Male C57BL/6 mice were used for CCI surgery, and post-CCI neurobehavioral deficits were assessed from 1 h after injury through 21 days post-injury (dpi). Results OBB treatment reduced the lipopolysaccharide-triggered elevated levels of reactive oxygen species, nitric oxide, and nuclear factor kappa B (NF-κB) in BV2 microglial cells, indicating a neuroprotective potential. CCI-operated mice exhibited significant neurological deficits on 1, 3, and 5 dpi in neurological severity scoring and rotarod assay. OBB (25 and 50 mg/kg/day) and OBB-NC (3 mg/kg/day) ameliorated these neurological aberrations. Mice subjected to CCI surgery also displayed anxiogenic- and depression-like behaviours, and cognitive impairments in forced-swimming test and elevated-zero maze, and novel object recognition task, respectively. Administration of OBB reduced these long-term neuropsychiatric complications, and also levels of toll-like receptor 4 (TLR4), high-motility group protein 1 (HMGB1), NF-κB, tumour necrosis factor-alpha and interleukin 6 cytokines in the ipsilateral cortex of mice. Conclusion We suggest that the administration of OBB offers neuroprotective effects via inhibition of HMGB1-mediated TLR4/NFκB pathway.

Antiedematogenic and Analgesic Activities of Abietic Acid in Mice.

Exacerbated inflammatory responses to harmful stimuli can lead to significant pain, edema, and other complications that require pharmacological intervention. Abietic acid (AA) is a diterpene found as a significant constituent in pine species, and evidence has identified its biological potential. The present study aimed to evaluate abietic acid's antiedematogenic and anti-inflammatory activity in mice. Swiss mice (Mus musculus) weighing 20-30 g were treated with AA at 50, 100, and 200 mg/kg. The central nervous system (CNS) effects were evaluated using open-field and rotarod assays. The antinociceptive and anti-inflammatory screening was assessed by the acetic acid and formalin tests. The antiedematogenic activity was investigated by measuring paw edema induced by carrageenan, dextran, histamine, arachidonic acid, and prostaglandin, in addition to using a granuloma model. The oral administration of abietic acid (200 mg/Kg) showed no evidence of CNS effects. The compound also exhibited significant antiedematogenic and anti-inflammatory activities in the carrageenan and dextran models, mostly related to the inhibition of myeloperoxidase (MOP) activity and histamine action and, to a lesser extent, the inhibition of eicosanoid-dependent pathways. In the granuloma model, abietic acid's effect was less expressive than in the acute models investigated in this study. In conclusion, abietic acid has analgesic and antiedematogenic activities related to anti-inflammatory mechanisms.

Screening of the action mechanisms involved in the antinociceptive effect of isopulegol and its complex in cyclodextrin using acute nociception models in mice

Screening of the action mechanisms involved in the antinociceptive effect of isopulegol and its complex in cyclodextrin using acute nociception models in mice

The herbicides glyphosate and glufosinate and the cyanotoxin β-N-methylamino-l-alanine induce long-term motor disorders following postnatal exposure: the importance of prior asymptomatic maternal inflammatory sensitization

BackgroundPrenatal maternal immune activation (MIA) and/or perinatal exposure to various xenobiotics have been identified as risk factors for neurological disorders, including neurodegenerative diseases. Epidemiological data suggest an association between early multi-exposures to various insults and neuropathologies. The “multiple-hit hypothesis” assumes that prenatal inflammation makes the brain more susceptible to subsequent exposure to several kinds of neurotoxins. To explore this hypothesis and its pathological consequences, a behavioral longitudinal procedure was performed after prenatal sensitization and postnatal exposure to low doses of pollutants.MethodsMaternal exposure to an acute immune challenge (first hit) was induced by an asymptomatic lipopolysaccharide (LPS) dose (0.008 mg/kg) in mice. This sensitization was followed by exposing the offspring to environmental chemicals (second hit) postnatally, by the oral route. The chemicals used were low doses of the cyanotoxin β-N-methylamino-l-alanine (BMAA; 50 mg/kg), the herbicide glufosinate ammonium (GLA; 0.2 mg/kg) or the pesticide glyphosate (GLY; 5 mg/kg). After assessing maternal parameters, a longitudinal behavioral assessment was carried out on the offspring in order to evaluate motor and emotional abilities in adolescence and adulthood.ResultsWe showed that the low LPS immune challenge was an asymptomatic MIA. Even though a significant increase in systemic pro-inflammatory cytokines was detected in the dams, no maternal behavioral defects were observed. In addition, as shown by rotarod assays and open field tests, this prenatal LPS administration alone did not show any behavioral disruption in offspring. Interestingly, our data showed that offspring subjected to both MIA and post-natal BMAA or GLA exposure displayed motor and anxiety behavioral impairments during adolescence and adulthood. However, this synergistic effect was not observed in the GLY-exposed offspring.ConclusionThese data demonstrated that prenatal and asymptomatic immune sensitization represents a priming effect to subsequent exposure to low doses of pollutants. These double hits act in synergy to induce motor neuron disease-related phenotypes in offspring. Thus, our data strongly emphasize that multiple exposures for developmental neurotoxicity regulatory assessment must be considered. This work paves the way for future studies aiming at deciphering cellular pathways involved in these sensitization processes.

Analgesic and Side Effect Profiles of Novel Alpha-2 Adrenergic Receptor Agonists

<b>Abstract ID 24150</b> <b>Poster Board 316</b> Alpha 2 adrenergic receptor (α₂-AR) agonists are effective analgesics while avoiding concerns surrounding opioid analgesia including misuse, diversion, and overdose. Clonidine, the best characterized α₂-AR agonist, is limited in widespread use for analgesia by side effects including hypotension and sedation. We therefore developed a series of novel, non-opioid α₂-AR agonists and assessed their kinetics, analgesic efficacy, α₂-AR subtype affinity, and side effects. <b>Methods:</b> We designed and synthesized novel α₂-AR agonists, then determined dose ranges in female and male ICR mice (21-30 g) by intrathecally injecting the agonists with substance P to induce quantifiable transient nociceptive behaviors. Mice were pre-treated with either an in-class control or the newly developed α₂-AR agonists as single agents or in combinations and the maximum percent effect (%MPE) in reduction of the Substance P (SP)-induced nociception was calculated as compared to saline control. Following MPE calculation, motor impairment was assessed by administration of high effective doses in the open field and rotarod assays. In parallel, the novel agonists were administered in spared nerve injury (model of neuropathic pain), and in SPARC-null transgenic mice (model of low back pain). <b>Results:</b> The novel α₂-AR agonists, delivered either singly or in combination, were effective in reducing nociceptive behaviors in the SP assay. The efficacy of the novel compounds was inhibited by idazoxan or efaroxan, but not naloxone, supporting action at α₂-AR and not opioid receptors. Additionally, the novel α₂-AR agonists were also effective at reducing expression of pain behavior in chronic rodent models of neuropathic and low back pain. Additionally, the compounds showed attenuated sedation as compared to in-class controls. The pursuit of α₂-AR agonists may represent an improved non-opioid analgesic strategy. <b>Acknowledgments:</b> These studies were conducted with support from the College of Pharmacy, Winston and Maxine Wallin Neuroscience Discovery Fund, Center for Drug Design and the Dept of Anesthesiology.

KCC2 downregulation after sciatic nerve injury enhances motor function recovery

Injury to mature neurons induces downregulated KCC2 expression and activity, resulting in elevated intracellular [Cl−] and depolarized GABAergic signaling. This phenotype mirrors immature neurons wherein GABA-evoked depolarizations facilitate neuronal circuit maturation. Thus, injury-induced KCC2 downregulation is broadly speculated to similarly facilitate neuronal circuit repair. We test this hypothesis in spinal cord motoneurons injured by sciatic nerve crush, using transgenic (CaMKII-KCC2) mice wherein conditional CaMKIIα promoter-KCC2 expression coupling selectively prevents injury-induced KCC2 downregulation. We demonstrate, via an accelerating rotarod assay, impaired motor function recovery in CaMKII-KCC2 mice relative to wild-type mice. Across both cohorts, we observe similar motoneuron survival and re-innervation rates, but differing post-injury reorganization patterns of synaptic input to motoneuron somas—for wild-type, both VGLUT1-positive (excitatory) and GAD67-positive (inhibitory) terminal counts decrease; for CaMKII-KCC2, only VGLUT1-positive terminal counts decrease. Finally, we recapitulate the impaired motor function recovery of CaMKII-KCC2 mice in wild-type mice by administering local spinal cord injections of bicuculline (GABAA receptor blockade) or bumetanide (lowers intracellular [Cl−] by NKCC1 blockade) during the early post-injury period. Thus, our results provide direct evidence that injury-induced KCC2 downregulation enhances motor function recovery and suggest an underlying mechanism of depolarizing GABAergic signaling driving adaptive reconfiguration of presynaptic GABAergic input.

Temporal Silencing of Purkinje Cell Neurotransmission Reveals a Dynamic Role for Cerebellar Function in Neurodevelopment (P10-9.006)

<h3>Objective:</h3> To determine whether differential timing of disrupted cerebellar function influences the nature and severity of associated neurodevelopmental outcomes. <h3>Background:</h3> Disruptions of cerebellar function have been increasingly implicated in the pathogenesis of a wide array of neurodevelopmental disorders. While there has been increasing focus on genetically mediated etiologies of disrupted cerebellar function, less attention has been given to acquired etiologies although they underlie diseases with high incidence and prevalence, such as the neurodevelopmental disability associated with prematurity and autism spectrum disorders. The present study uses mouse transgenics to develop a synthetic model of cerebellar developmental dysfunction and interrogates the role of cerebellar neurotransmission in early brain development. <h3>Design/Methods:</h3> Using inducible tissue specific Cre-mediated recombination the present model allows for spatial and temporal induction of cerebellar dysfunction through timed excision of the vesicular GABA transporter (VGAT) specifically in Purkinje cells. Using this line, Purkinje cell neurotransmission is silenced <i>in utero</i> (EarlyOff) or at time of weaning (LateOff), corresponding developmentally to the immature and mature cerebellum. Mouse behavior and the electrophysiologic profile of cerebellar nuclear neurons was then performed comparing EarlyOff, LateOff, and control animals at 8–10 weeks of life. <h3>Results:</h3> Compared to controls EarlyOFF showed significantly altered gross motor behavior (rotarod assay, footprinting), social behavior (3-chamber assay), and hyperactivity (open field assay). Compared to controls, LateOff had equivalent performance on gross motor assays but showed significant hyperactivity. Social tests are ongoing. Cerebellar nuclear electrophysiology from awake behaving animals revealed significantly different and divergent spike profiles between EarlyOff, LateOff, and controls. <h3>Conclusions:</h3> The developmental timing of cerebellar dysfunction leads to discrepant behavioral and electrophysiologic profiles. These findings underline that the disparate phenotypes of neurodevelopmental disability associated with prematurity and autism may nonetheless have shared cerebellar etiology, emphasize the necessity of understanding how cerebellar nuclear signaling influences broad cortical function, and reveal a potential target for neuromodulatory intervention. <b>Disclosure:</b> Dr. Gill has received personal compensation in the range of $500-$4,999 for serving as an Expert Witness for Elite Medical Experts. The institution of Dr. Gill has received research support from NIH-NINDS. Miss Nguyen has nothing to disclose. Roy Sillitoe has nothing to disclose.

LQM10, a guanylhydrazone derivative, reduces nociceptive and inflammatory responses in mice.

In the present study, we examined the antinociceptive and anti-inflammatory activities of a guanylhydrazone derivative, (E)-(3,5-di-tert-butyl-4-hydroxybenzylidene)-2-guanylhydrazone hydrochloride (LQM10), in mice. The antinociceptive effect was determined by assessing behavioural responses in different pain models, while anti-inflammatory activity was examined in carrageenan-induced pleurisy. Intraperitoneal LQM10 administration reduced the acetic acid-induced nociceptive behaviour, a phenomenon that was unaltered by pretreatment with yohimbine, atropine, naloxone or glibenclamide. In the formalin assay, LQM10 reduced nociceptive behaviour only in the second phase, indicating an inhibitory effect on inflammatory pain. LQM10 did not alter the pain latency in the hot plate assay and did not impact the locomotor activity of mice in the rotarod assay. In the carrageenan-induced pleurisy assay, LQM10 treatment inhibited critical events involved in inflammatory responses, namely, leucocyte recruitment, plasma leakage and increased inflammatory mediators (tumour necrosis factor Like Properties of Chalchones and Flavonoid Derivatives [TNF]-α and interleukin [IL]-1β) in the pleural exudate. Overall, these results indicate that LQM10 exhibits antinociceptive effects associated with peripheral mechanisms and anti-inflammatory activity mediated via a reduction in leucocyte migration and proinflammatory mediators, rendering this compound a promising candidate for treating pain and inflammatory process.

Mechanisms of Actions Involved in The Antinociceptive Effect of Estragole and its β-Cyclodextrin Inclusion Complex in Animal Models.

(1) Background: estragole is a monoterpene found in the essential oils of several aromatic plants, which can be used for several pharmacological activities. The aim of this study was to evaluate the antinociceptive effect of estragole (Es) and its β-cyclodextrins inclusion complex (Es/β-CD). (2) Methods: the effects of Es and Es/β-CD on the central nervous system (CNS) were evaluated through open field and rota-rod assays, and the antinociceptive effect in formalin models, abdominal writhing induced by acetic acid, hot plate, tail flick test and plantar mechanical hyperalgesia. (3) Results: Es and Es/β-CD showed no alterations on the CNS evaluated parameters and the results suggested there was an antinociceptive action in the formalin, abdominal writhing, hot plate, tail flick tests and plantar mechanical hyperalgesia, proposing the involvement of the nitric oxide, glutamatergic signaling pathways, cyclic guanosine monophosphate and vanilloid pathways. (4) Conclusion: the results suggest that Es and Es/β-CD have a promising antinociceptive potential as a possible alternative for the pharmacological treatment of pain, also showing that the encapsulation of Es in β-cyclodextrins probably improves its pharmacological properties, since the complexation process involves much lower amounts of the compound, contributing to better bioavailability and a lower probability of adverse effect development.

Characterization of CM-398, a Novel Selective Sigma-2 Receptor Ligand, as a Potential Therapeutic for Neuropathic Pain.

Sigma receptors modulate nociception, offering a potential therapeutic target to treat pain, but relatively little is known regarding the role of sigma-2 receptors (S2R) in nociception. The purpose of this study was to investigate the in vivo analgesic and anti-allodynic activity and liabilities of a novel S2R selective ligand, 1-[4-(6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolin-2-yl)butyl]-3-methyl-1,3-dihydro-1,3-benzimidazol-2-one (CM-398). The inhibition of thermal, induced chemical, or inflammatory pain as well as the allodynia resulting from chronic nerve constriction injury (CCI) model of neuropathic pain were assessed in male mice. CM-398 dose-dependently (10–45 mg/kg i.p.) reduced mechanical allodynia in the CCI neuropathic pain model, equivalent at the higher dose to the effect of the control analgesic gabapentin (50 mg/kg i.p.). Likewise, pretreatment (i.p.) with CM-398 dose-dependently produced antinociception in the acetic acid writhing test (ED50 (and 95% C.I.) = 14.7 (10.6–20) mg/kg, i.p.) and the formalin assay (ED50 (and 95% C.I.) = 0.86 (0.44–1.81) mg/kg, i.p.) but was without effect in the 55 °C warm-water tail-withdrawal assay. A high dose of CM-398 (45 mg/kg, i.p.) exhibited modest locomotor impairment in a rotarod assay and conditioned place aversion, potentially complicating the interpretation of nociceptive testing. However, in an operant pain model resistant to these confounds, mice experiencing CCI and treated with CM-398 demonstrated robust conditioned place preference. Overall, these results demonstrate the S2R selective antagonist CM-398 produces antinociception and anti-allodynia with fewer liabilities than established therapeutics, adding to emerging data suggesting possible mediation of nociception by S2R, and the development of S2R ligands as potential treatments for chronic pain.

In utero exposure to dietary emulsifier alters the behavioral activity in offspring

ObjectivePediatric mental health disorder is a combination of neuroinflammatory conditions with unknown etiology and currently, there are less awareness on the impacts of food additives on pediatric neuroinflammatory conditions and adolescent mental health disorders. Food additives such as dietary emulsifier (DE) (polysorbate 80, carrageenan and maltodextrin) are added to a variety of processed foods, and their consumption has increased dramatically worldwide which could be a risk factor for pediatric mental health disorders. Therefore, there is a critical need to understand the impact of maternal exposure to food additives associated pediatric mental health and the underlying mechanism.Materials and MethodsBehavioral testing such as tail flick assay, radial arm, rotarod and hot plate assay was done on the offspring from both control and DE exposed mice for the impaired motor activity, pain sensitivity and cognitive behavior. Colonic microbial composition was determined through 16sRNA pyrosequencing of fecal DNA samples from control and in utero DE‐exposed offspring. Level of pro inflammatory cytokines in the colon tissue as well as the serum sample was measured using Multianalyte cytokine assay kit from Qiagen.Summary of ResultsOur results show that in utero exposure to DE leads to decreased brain sizes and impaired motor learning in the offspring. Additionally, in utero exposure to DE leads to decreased pain sensitivity as a sign of stress in offspring. In utero exposure to DE shows on onset of cognitive impairment in offspring. In utero exposure to DE leads to an elevated M1 macrophage cytokine profile and CLGI symptoms in the gastrointestinal tract of offspring. In utero exposure to DE leads to gut dysbiosis in offspring. Among the DE‐exposed adolescents, the male offspring had significantly higher impact on these parameters compared to the DE‐exposed female offspring. In utero exposure to DE leads to imbalance in serum levels of dihydrotestosterone (DHT) and estradiol (E2) in the Offspring.ConclusionOur data suggest that maternal exposure to food additive is associated with the male biased cognitive impairment and neurobehavioral changes in the offspring. In future, we will determine the specific mechanism responsible for the sex specific alternation in offspring born to DE exposed mother to develop a preventative and therapeutic strategies.

The voltage-gated Ca2+ channel subunit α2δ-4 regulates locomotor behavior and sensorimotor gating in mice.

Voltage-gated Ca2+ channels are critical for the development and mature function of the nervous system. Variants in the CACNA2D4 gene encoding the α2δ-4 auxiliary subunit of these channels are associated with neuropsychiatric and neurodevelopmental disorders. α2δ-4 is prominently expressed in the retina and is crucial for vision, but extra-retinal functions of α2δ-4 have not been investigated. Here, we sought to fill this gap by analyzing the behavioral phenotypes of α2δ-4 knockout (KO) mice. α2δ-4 KO mice (both males and females) exhibited significant impairments in prepulse inhibition that were unlikely to result from the modestly elevated auditory brainstem response thresholds. Whereas α2δ-4 KO mice of both sexes were hyperactive in various assays, only females showed impaired motor coordination in the rotarod assay. α2δ-4 KO mice exhibited anxiolytic and anti-depressive behaviors in the elevated plus maze and tail suspension tests, respectively. Our results reveal an unexpected role for α2δ-4 in sensorimotor gating and motor function and identify α2δ-4 KO mice as a novel model for studying the pathophysiology associated with CACNA2D4 variants.

Examination of the Novel Sigma-1 Receptor Antagonist, SI 1/28, for Antinociceptive and Anti-allodynic Efficacy against Multiple Types of Nociception with Fewer Liabilities of Use.

Neuropathic pain is a significant problem with few effective treatments lacking adverse effects. The sigma-1 receptor (S1R) is a potential therapeutic target for neuropathic pain, as antagonists for this receptor effectively ameliorate pain in both preclinical and clinical studies. The current research examines the antinociceptive and anti-allodynic efficacy of SI 1/28, a recently reported benzylpiperazine derivative and analog of the S1R antagonist SI 1/13, that was 423-fold more selective for S1R over the sigma-2 receptor (S2R). In addition, possible liabilities of respiration, sedation, and drug reinforcement caused by SI 1/28 have been evaluated. Inflammatory and chemical nociception, chronic nerve constriction injury (CCI) induced mechanical allodynia, and adverse effects of sedation in a rotarod assay, conditioned place preference (CPP), and changes in breath rate and locomotor activity were assessed after i.p. administration of SI 1/28. Pretreatment with SI 1/28 produced dose-dependent antinociception in the formalin test, with an ED50 (and 95% C.I.) value of 13.2 (7.42–28.3) mg/kg, i.p. Likewise, SI 1/28 produced dose-dependent antinociception against visceral nociception and anti-allodynia against CCI-induced neuropathic pain. SI 1/28 demonstrated no impairment of locomotor activity, conditioned place preference, or respiratory depression. In summary, SI 1/28 proved efficacious in the treatment of acute inflammatory pain and chronic neuropathy without liabilities at therapeutic doses, supporting the development of S1R antagonists as therapeutics for chronic pain.

K+/Cl- co-transporter-2 upmodulation: a multi-modal therapy to treat spinal cord injury.

K+/Cl- co-transporter-2 upmodulation: a multi-modal therapy to treat spinal cord injury.

Different Types of Environmental Stressors Could Have Disruptive or Constructive Effects on Vestibular Compensation

Background and Aim: Stress could play either helpful or harmful roles in vestibular compensation, the process of recovery after vestibular system lesions. Herein, we examined the effect of two stressor types on vestibular compensation: chronic anxiety disorder induced by early maternal separation (MS), and caloric restriction by an intermittent fasting (IF) diet. Methods: Male Wistar rats (n=56) received maternal separation (the MS group), intermittent fasting (IF group), unilateral vestibular deafferentation (UVD group), or a mixture of these interventions (UVD+IF, UVD+MS, and UVD+IF+MS). All the groups were compared with control animals. The animals’ balance, motor coordination, anxiety, locomotor activity, and serum cortisol levels were evaluated by rotarod, open field, and enzyme-linked immunosorbent assay methods, respectively. The data were compared with those of the healthy control (HC) group. Results: The UVD animals did not show a significant change in the time on the rod, except for the IF+UVD group (p=0.04). There was no significant difference between the experimental groups on the open field indices, except for the MS+IF+UVD group which traveled a significantly less total distance (p=0.02). Serum cortisol levels were significantly higher than HCs for all the groups except for the sham saline and IF+UVD group (p&lt;0.05). Conclusion: IF seems to promote compensation after UVD, while MS may disrupt it. However, IF loses its beneficial outcomes if the animal has received another source of stress, i.e. MS.

Protopine promotes the proteasomal degradation of pathological tau in Alzheimer's disease models via HDAC6 inhibition

Collective evidences have indicated that intracellular accumulation of hyperphosphorylated tau forms neurofibrillary tangles in the brain, which impairs memory, cognition and affects social activities in Alzheimer's disease (AD). To investigate the tau-reducing, and memory-enhancing properties of protopine (PRO), a natural alkaloid isolated from Chinese herbal medicine Corydalis yanhusuo (Yanhusuo in Chinese). By using Histone deacetylase 6 (HDAC6) profiling and immunoprecipitation assays, we assessed that PRO mediated the heat shock protein 90 (HSP90) chaperonic activities for the degradation of pathological tau in AD cell culture models. To study the efficacy of PRO in vivo, we employed 3xTg-AD and P301S tau mice models. Liquid chromatography/quadrupole time-of-flight mass spectrometry was used to analyze the pharmacokinetic profile of PRO. Seven-month-old 3xTg-AD mice and 1.5-month-old P301S mice were administered PRO (1 and 2.5mg/kg) orally every day. Morris water maze, contextual fear conditioning and rotarod assays were applied for studying memory functions. Sarkosyl differential centrifugation was used to analyze soluble and insoluble tau. Immunohistochemical analysis were performed to determine tau deposits in AD mice's brain sections. Molecular docking, binding affinity studies and primary cell culture studies were performed to demonstrate the mechanism of action of PRO in silico and in vitro. Our pharmacokinetic profiling demonstrated that PRO significantly entered the brain at a concentration of 289.47ng/g, and specifically attenuated tau pathology, improved learning and memory functions in both 3xTg-AD and P301S mice. Docking, binding affinity studies, and fluorometric assays demonstrated that PRO directly bound to the catalytic domain 1 (CD1) of HDAC6 and down-regulated its activity. In primary cortical neurons, PRO enhanced acetylation of α-tubulin, indicating HDAC6 inhibition. Meanwhile, PRO promoted the ubiquitination of tau and recruited heat shock protein 70 (HSP70) and heat shock cognate complex 71 (HSC70) for the degradation of pathological tau via the ubiquitin-proteasomal system (UPS). We identified PRO as a natural HDAC6 inhibitor that attenuated tau pathology and improved memory dysfunctions in AD mice. The findings from this study provides a strong justification for future clinical development of plant-derived protopine as a novel agent for the treatment of tau-related neurodegenerative diseases.