A simple scoring of beam walking performance after spinal cord injury in mice

Neuroprotective effects of Morus alba ethanolic extract against rotenone-induced neurodegeneration and motor impairments in mouse model

Morus alba formulations impart neuroprotective properties against dementia, oxidative stress and mitochondrial impairments. The current study aimed to evaluate the neuroprotective potential of ethanolic extract of Morus alba (EMA) on motor impairments. GC-MS characterization of extract revealed active ingredients. Adult mice were exposed to rotenone to induce neurodegeneration and motor dysfunctions. EMA reduced striatal dopamine depletion and motor impairment. Candidate genes for anti-oxidant enzymes, dopamine transmission, synaptogenesis and mitochondrial regulator were significantly modulated in EMA exposed mice. Collectively, EMA imparted preventive action against rotenone-mediated brain damage, augmented antioxidant capabilities and prevented motor dysfunctions. It is suggested that MA as a potential medicinal plant for development of protective strategies in relevant clinical applications.

Inhibition of the RNA Regulator HuR Mitigates Spinal Cord Injury by Potently Suppressing Post-Injury Neuroinflammation

Neuroinflammation is a major driver of secondary tissue damage after spinal cord injury (SCI). Within minutes after SCI, activated microglia and astrocytes produce proinflammatory mediators such as TNF-α, IL-6, iNOS, and COX-2 which induce tissue injury through cytotoxicity, vascular hyperpermeability, and secondary ischemia. The inflammatory cascade is amplified by chemokines like CCL2 and CXCL1 which recruit immune cells to the injured site. HuR is an RNA regulator that promotes glial expression of many proinflammatory factors by binding to adenylate- and uridylate-rich elements in the 3' untranslated regions of their mRNAs. SRI-42127 is a small molecule which blocks HuR function by preventing its nucleocytoplasmic translocation. This study aimed to evaluate the potential of SRI-42127 to suppress neuroinflammation after SCI and improve functional outcome. Adult female mice underwent a T10 contusion injury and received SRI-42127 1 h post injury for up to 5 days. Locomotor function was assessed by open field testing, balance beam, and rotarod. Immunohistochemistry was used to assess lesion size, neuronal loss, myelin sparing, microglial/astroglial activation, and HuR localization. Inflammatory mediator expression was assessed by qPCR, immunohistochemistry, ELISA, or western blot. We found that SRI-42127 treatment significantly attenuated loss of locomotor function and post-SCI pain. There was a reduction in lesion size and neuronal loss with an increase in myelin sparing. Microglia and astrocytes showed reduced activation and reduced nucleocytoplasmic translocation of HuR. There was a striking suppression of proinflammatory mediators at the epicenter along with peripheral suppression of inflammatory responses in serum, liver, and spleen. In conclusion, HuR inhibition with SRI-42127 may be a viable therapeutic approach for suppressing neuroinflammatory responses after SCI and improving functional outcome.

Exploring astaxanthin: a comprehensive review on its pharmacokinetics properties and neuroprotective potential

BACKGROUND

Carotenoids are naturally occurring bio-pigments found in microalgae, plants, fungi, bacteria, and various aquatic animals. They are generally classified into carotenes and xanthophylls based on their structural features. Among them, astaxanthin-a xanthophyll carotenoid-has attracted increasing attention due to its potent antioxidant, anti-inflammatory, and anti-apoptotic properties, which contribute to a range of health benefits.

METHOD

This review highlights the structural features, physicochemical properties, pharmacokinetics, and therapeutic potential of astaxanthin, particularly focusing on its neuroprotective effects in neurological disorders. To provide a comprehensive overview, we systematically searched published articles across Scopus, Google Scholar, PubMed, and Medline databases from inception to January 1, 2025.

RESULTS

Recent advancements in drug formulation and delivery technologies have enhanced astaxanthin's ability to cross the blood-brain barrier (BBB), significantly increasing its potential as a therapeutic agent for neurological diseases.

CONCLUSION

With its multifaceted biological effects and growing evidence of neuroprotection, astaxanthin shows great promise in the treatment of neurological disorders, particularly stroke. These findings support its future development and application in pharmaceutical strategies aimed at brain health.

Methods for Assessing Neurodevelopmental Disorders in Mice: A Critical Review of Behavioral Tests and Methodological Considerations Searching to Improve Reliability

Many neurobehavioral tests are used for the assessment of human-like behaviors in animals. Most of them were developed in rodents and are used for the assessment of animal models that mimic human neurodevelopmental and neuropsychiatric disorders (NDDs). We have described tests for assessing social behavior, social interaction, and social communication; tests for restricted and repetitive behaviors; tests for cognitive impairment, for sensory stimuli, for anxiety like behavior, and for motor coordination deviations. These tests are used to demonstrate autistic-like behavior as well as other NDDs. We described possible general pitfalls in the performance of such studies, as well as probable individual errors for each group of tests assessing specific behavior. The mentioned pitfalls may induce crucial errors in the interpretation of the results, minimizing the reliability of specific models of defined human NDD. It is imperative to minimize these pitfalls and use sufficient and reliable tests that can demonstrate as many of the traits of the human disorder, grade the severity of the specific deviations and the severity of the tested NDD by using a scoring system. Due to possible gender differences in the clinical presentations of NDD, it is important to carry out studies on males and females.

Tetrapleura tetraptera fruit extracts ameliorate pentylenetetrazol-induced seizures as well as ensuing cognitive deficit and oxidative stress

Kindling is an experimental-induced seizure consistent with epilepsy disease, a chronic neurological disorder characterised by spontaneous and repeated seizures. This disease is associated with oxidative stress, and most therapeutic strategies against epilepsy aim at improving the antioxidant defence mechanism in the brain. However, prolonged usage and associated adverse side effects limit antiepileptics, warranting natural antioxidant patronage. The present study investigated the behavioural and antioxidant actions of Tetrapleura tetraptera fruit extracts (TT) against pentylenetetrazol (PTZ)-kindling rats. Twenty-five male Wistar rats (150-180 g) were assigned into five groups (1-5, n = 5): Control (normal saline, 5 ml/kg body weight, b.w.), PTZ-only (40 mg/kg/b.w. i.p.), and groups 3-5 administered PTZ (40 mg/kg/b.w. i.p.) after, respectively, receiving oral TT (500 mg/kg/b.w.), TT flavonoid (fTT, 50 mg/kg/b.w.), and sodium valproate (SV, 15 mg/kg/b.w.). All administrations were carried out 48 hourly for 21 days. In the end, buried food, novel object recognition (NOR), Y-maze, elevated plus maze (EPM), and beam walk tests were done, and the rats were sacrificed. Whole brains were processed for antioxidant assays. The results showed a high (p <.05) seizure score and buried food test latency, preference for the familiar object in the NOR test, aversion to open-arm and reduced grooming in the EPM, reduced beam walk latency, elevated brain malondialdehyde (MDA), and decreased superoxide dismutase (SOD) in the PTZ group. The TT, fTT, and SV suppressed seizure, decreased buried food latency, `preference for the novel object and open-arm, increased grooming, decreased brain MDA, and elevated SOD. In conclusion, TT extracts protected against PTZ-induced cognitive deficits and brain oxidative stress, with results similar to those of the standard anticonvulsant drug, SV.

Forestwalk: A Machine Learning Workflow Brings New Insights Into Posture and Balance in Rodent Beam Walking

The beam walk is widely used to study coordination and balance in rodents. While the task has ethological validity, the main endpoints of "foot slip counts" and "time to cross" are prone to human-rater variability and offer limited sensitivity and specificity. We asked if machine learning-based methods could reveal previously hidden, but biologically relevant, insights from the task. Marker-less pose estimation, using DeepLabCut, was deployed to label 13 anatomical key points on mice traversing the beam. Next, we automated classical endpoint detection, including foot slips, with high recall (> 90%) and precision (> 80%). Using data derived from key point tracking, a total of 395 features were engineered and a random forest classifier deployed that, together with skeletal visualizations, could test for group differences and identify determinant features. This workflow, named Forestwalk, uncovered pharmacological treatment effects in C57BL/6J mice, revealed phenotypes in transgenic mice used to study Angelman syndrome and SLC6A1-related neurodevelopmental disorder, and will facilitate a deeper understanding of how the brain controls balance in health and disease.

Inner and outer penetrating spinal cord injuries lead to distinct overground walking in mice

Spinal cord injury (SCI) is a devastating mechanical trauma. Although locomotion of model animals that mimic contusion SCI was actively examined, locomotion after penetrating SCI caused by sharp objects was not extensively studied. Severity of walking difficulty after partial transection of the spinal cord including penetrating SCI likely depends on the regions affected. Therefore, we compared beam walking and overground walking between mice after penetrating SCI at inner spinal cord region and mice with the injury at the outer region. Mice with the both penetrating SCIs did not display changes in beam walking. When appearance and movements of hindlimbs during overground walking was rated using Basso Mouse Scale for locomotion (BMS), however, mice with inner penetrating SCI showed low score shortly after the SCI. However, the score became high at later time points, as seen in contusion SCI mice. By contrast, BMS score did not decrease shortly after the outer penetrating SCI. However, the score became low 3 weeks after the SCI. As quantitative values during overground walking, movement duration in an open field were shorter at 1 day after the two penetrating SCIs. However, slower moving speed and fewer number of movement at 1 day were specific to mice with inner and outer penetrating SCIs, respectively. Moreover, BMS score was correlated with walking distance in open field only in mice with inner penetrating SCI. Thus, inner and outer penetrating SCI cause difficulty in overground walking with different severity and progress.

Probing polypharmacy, ageing and sex effects on physical function using different tests

BACKGROUND

Ageing, sex and polypharmacy affect physical function.

OBJECTIVES

This mouse study investigates how ageing, sex and polypharmacy interact and affect grip strength, balance beam and wire hang, correlating and comparing the different test results between and within subgroups.

METHODS

Young (2.5 months) and old (21.5 months) C57BL/6 J male and female mice (n = 10-6/group) were assessed for physical function at baseline on grip strength, balance beam and wire hang with three trials of 60 s (WH60s) and one trial of 300 s (WH300s). Mice were randomised to control or diet containing a high Drug Burden Index (DBI, total anticholinergic and sedative drug exposure) polypharmacy regimen (metoprolol, simvastatin, citalopram, oxycodone and oxybutynin at therapeutic oral doses). Following 6-8 weeks of treatment, mice were reassessed.

RESULTS

High DBI polypharmacy and control mice both showed age group differences on all tests (p < 0.05). Only control mice showed sex differences, with females outperforming males on the WH60s and balance beam for old mice, WH300s for young mice (p < 0.05). Polypharmacy reduced grip strength in all subgroups (p < 0.05) and only in old females reduced wire hang time and cumulative behaviour and balance beam time and %walked (p < 0.05). Physical function assessments were all correlated with each other, with differences between subgroups (p < 0.05), and mice within subgroups showed interindividual variability in performance.

CONCLUSION

Age, sex and polypharmacy have variable effects on different tests, and behavioural measures are useful adjuvants to assessing performance. There was considerable within-group variability in change in measures over time. These findings can inform design and sample size of future studies.

[Validation of a C57/BL6J mouse model of focal cerebral ischemia established by electrocoagulation of the middle cerebral artery]

OBJECTIVE

To modify the method for establishing mouse models of middle cerebral artery occlusion (MCAO)-induced focal cerebral ischemia using electrocoagulation.

METHODS

Forty-six C57/BL6J male mice were divided into MCAO model group (n=34) and sham-operated group (n=12). In the model group, MCAO was induced by permanent coagulation of the right middle cerebral artery (MCA) using a coagulator, and cerebral blood flow perfusion was monitored before and at 20 min and 1 day after modeling. Neurological deficits of the mice at 1, 7, and 14 days after modeling were evaluated using Longa score, mNSS score, beam walking test, cylinder test and corner test. TTC staining was used to measure the cerebral infarct size, and Western blotting was performed to detect the expressions of BDNF, GFAP and DCX proteins in the ischemic cortex.

RESULTS

The mice in the model group showed significantly reduced cerebral blood flow in the MCA on the ischemic side and obvious neurological deficits with increased forelimb use asymmetry on days 1, 7 and 14 after modeling (P < 0.05). In the cerebral cortex on the ischemic side of the model mice, the expressions of GFAP and DCX increased significantly at 1, 7, and 14 days (P < 0.05) and the expression of BDNF increased at 1 day after modeling ischemia (P < 0.05).

CONCLUSION

We successfully prepared mouse models of MCAO using a modified method by changing the electrocoagulation location from the distal location of the junction between the MCA and the inferior cerebral vein to a 2 mm segment medial to the junction between the MCA and the olfactory bundle.

Methods for evaluating gait associated dynamic balance and coordination in rodents

Balance is the dynamic and unconscious control of the body's centre of mass to maintain postural equilibrium. Regulated by the vestibular system, head movement and acceleration are processed by the brain to adjust joints. Several conditions result in a loss of balance, including Alzheimer's Disease, Parkinson's Disease, Menière's Disease and cervical spondylosis, all of which are caused by damage to certain parts of the vestibular pathways. Studies about the impairment of the vestibular system are challenging to carry out in human trials due to smaller study sizes limiting applications of the results and a lacking understanding of the human balance control mechanism. In contrast, more controlled research can be performed in animal studies which have fewer confounding factors than human models and allow specific conditions that affect balance to be replicated. Balance control can be studied using rodent balance-related behavioural tests after spinal or brain lesions, such as the Basso, Beattie and Bresnahan (BBB) Locomotor Scale, Foot Fault Scoring System, Ledged Beam Test, Beam Walking Test, and Ladder Beam Test, which are discussed in this review article along with their advantages and disadvantages. These tests can be performed in preclinical rodent models of femoral nerve injury, stroke, spinal cord injury and neurodegenerative diseases.