Residues of chlorpyrifos in the environment induce resistance in Aedes albopictus by affecting its olfactory system and neurotoxicity

Aedes albopictus, a virus-vector pest, is primarily controlled through the use of insecticides. In this study, we investigated the mechanisms of resistance in Ae. albopictus in terms of chlorpyrifos neurotoxicity to Ae. albopictus and its effects on the olfactory system. We assessed Ca2+-Mg2+-ATP levels, choline acetyltransferase (ChAT), Monoamine oxidase (MAO), odorant-binding proteins (OBPs), and olfactory receptor (OR7) gene expression in Ae. albopictus using various assays including Y-shaped tube experiments and DanioVision analysis to evaluate macromotor behavior. Our findings revealed that cumulative exposure to chlorpyrifos reduced the activity of neurotoxic Ca2+-Mg2+-ATPase and ChAT enzymes in Ae. albopictus to varying degrees, suppressed MAO-B enzyme expression, altered OBPs and OR7 expression patterns, as well as affected evasive response, physical mobility, and cumulative locomotor time under chlorpyrifos stress conditions for Ae. albopictus individuals. Consequently, these changes led to decreased feeding ability, reproductive capacity, and avoidance behavior towards natural enemies in Ae. albopictus populations exposed to chlorpyrifos stressors over time. To adapt to unfavorable living environments, Ae. albopictus may develop certain tolerance mechanisms against organophosphorus pesticides. This study provides valuable insights for guiding rational insecticide usage or dosage adjustments targeting the nervous system of Ae. albopictus.

Focused ultrasound on the substantia nigra enables safe neurotensin-polyplex nanoparticle-mediated gene delivery to dopaminergic neurons intranasally and by blood circulation

Neurotensin-polyplex nanoparticles provide efficient gene transfection of nigral dopaminergic neurons when intracerebrally injected in preclinical trials of Parkinson's disease because they do not cross the blood-brain barrier (BBB). Therefore, this study aimed to open BBB with focused ultrasound (FUS) on the substantia nigra to attain systemic and intranasal transfections and evaluate its detrimental effect in rats. Systemically injected Evans Blue showed that a two-pulse FUS opened the nigral BBB. Accordingly, 35 μL of neurotensin-polyplex nanoparticles encompassing the green fluorescent protein plasmid (79.6 nm mean size and + 1.3 mV Zeta-potential) caused its expression in tyrosine hydroxylase(+) cells (dopaminergic neurons) of both substantiae nigrae upon delivery via internal carotid artery, retro-orbital venous sinus, or nasal mucosa 30 min after FUS. The intracarotid delivery yielded the highest transgene expression, followed by intranasal and venous administration. However, FUS caused neuroinflammation displayed by infiltrated lymphocytes (positive to cluster of differentiation 45), activated microglia (positive to ionized calcium-binding adaptor molecule 1), neurotoxic A1 astrocytes (positive to glial fibrillary acidic protein and complement component 3), and neurotrophic A2 astrocytes (positive to glial fibrillary acidic protein and S100 calcium-binding protein A10), that ended 15 days after FUS. Dopaminergic neurons and axonal projections decreased but recuperated basal values on day 15 after transfection, correlating with a decrease and recovery of locomotor behavior. In conclusion, FUS caused transient neuroinflammation and reversible neuronal affection but allowed systemic and intranasal transfection of dopaminergic neurons in both substantiae nigrae. Therefore, FUS could advance neurotensin-polyplex nanotechnology to clinical trials for Parkinson's disease.

Neurotoxic effects of 2-ethylhexyl diphenyl phosphate exposure on zebrafish larvae: Insight into inflammation-driven changes in early motor behavior

The extensive utilization and potential adverse impacts of the replacement flame-retardant 2-Ethylhexyl Diphenyl Phosphate (EHDPP) have raised concerns. Currently, there is limited knowledge regarding the developmental, neurological, and immunotoxic consequences of EHDPP exposure, as well as its potential behavioral outcomes. In this study, we undertook a comprehensive examination and characterization of the toxic effects over the EHDPP concentration range of 14-1400 nM. Our findings unveiled that EHDPP, even at an environmentally relevant concentration of 14 nM, exhibited excitatory neurotoxicity, eliciting a 13.5 % increase in the swimming speed of zebrafish larvae. This effect might be attributed to the potential influence of EHDPP on the release of neurotransmitters like serotonin and dopamine, which, in turn, mediated anxiety-like behavior in the zebrafish larvae. Conversely, sublethal dose EHDPP (1400 nM) exposure significantly suppressed the swimming vigor of zebrafish larvae, accompanied by morphological changes, abnormal behaviors, and alterations in intracerebral molecules. Transcriptomics revealed the underlying mechanism. The utilization of pathway inhibitors reshaped the inflammatory homeostasis and alleviated the toxicity induced by EHDPP exposure, anchoring the pivotal role played by the TLR4/NF-κB signaling pathway in EHDPP-induced adverse changes in zebrafish behavior and neurophysiology. This study observed the detrimental effects of EHDPP on fish sustainability at environmentally relevant concentrations, highlighting the practical significance for EHDPP risk management. Elucidating the toxic mechanisms of EHDPP will contribute to a deeper comprehension of how environmental pollutants can intricately influence human health.

Characterization of graded 6-Hydroxydopamine unilateral lesion in medial forebrain bundle of mice

Parkinson's disease (PD) is the second most common age-related neurodegenerative disease, with a progressive loss of dopaminergic cells and fibers. The purpose of this study was to use different doses of 6-hydroxydopamine (6-OHDA) injection into the medial forebrain bundle (MFB) of mice to mimic the different stages of the disease and to characterize in detail their motor and non-motor behavior, as well as neuropathological features in the nigrostriatal pathway. MFB were injected with 0.5 μg, 1 μg, 2 μg of 6-OHDA using a brain stereotaxic technique. 6-OHDA induced mitochondrial damage dose-dependently, as well as substantia nigra pars compacta (SNpc) tyrosine hydroxylase-positive (TH+) cell loss and striatal TH fiber loss. Activation of astrocytes and microglia in the SNpc and striatum were consistently observed at 7 weeks, suggesting a long-term glial response in the nigrostriatal system. Even with a partial or complete denervation of the nigrostriatal pathway, 6-OHDA did not cause anxiety, although depression-like behavior appeared. Certain gait disturbances were observed in 0.5 μg 6-OHDA lesioned mice, and more extensive in 1 μg group. Despite the loss of more neurons from 2 μg 6-OHDA, there was no further impairment in behaviors compared to 1 μg 6-OHDA. Our data have implications that 1 μg 6-OHDA was necessary and sufficient to induce motor and non-motor symptoms in mice, thus a valuable mouse tool to explore disease progression and new treatment in PD.

Do attentional focus cues affect the type or number of explicit rules? Proof of concepts of the self-invoking trigger or explicit knowledge hypotheses

Internal focus has been shown to be detrimental to performance by disrupting the motor system, whereas external focus enhances performance by promoting automaticity. One hypothesis, which explains the underlying mechanism of the disruption of the motor system, proposes that internal focus affects the type of thoughts (explicit rules) by invoking self-conscious, evaluative thoughts (McKay et al., 2015). In contrast, another hypothesis proposes that internal focus increases the number of explicit rules, loading working memory (Poolton et al., 2006). To examine the competing hypotheses, neurotypical young adults (22.98 ± 4.46 years old, n = 20 males, n = 40 females) were assigned to one of three groups: external focus (n = 20), internal focus (n = 20), and control (n = 20) groups, and practiced a reciprocal aiming task for two days with retention/transfer tests. Between trials, participant's thoughts were evaluated by an open-ended questionnaire. The type of explicit rules was analyzed using a chi-square test, and the number of explicit rules was analyzed using a mixed-effect Poisson regression. The results showed that external focus resulted in a greater proportion of explicit rules about the task and a lesser proportion of self-evaluative thoughts. The number of explicit rules did not differ between groups. Our results suggest that external focus may strengthen focus on task-relevant features, while internal focus moves people's attention away from important features, potentially explaining why the motor system is disrupted by internal focus.

Emotion in action: When emotions meet motor circuits

The brain is a remarkably complex organ responsible for a wide range of functions, including the modulation of emotional states and movement. Neuronal circuits are believed to play a crucial role in integrating sensory, cognitive, and emotional information to ultimately guide motor behavior. Over the years, numerous studies employing diverse techniques such as electrophysiology, imaging, and optogenetics have revealed a complex network of neural circuits involved in the regulation of emotional or motor processes. Emotions can exert a substantial influence on motor performance, encompassing both everyday activities and pathological conditions. The aim of this review is to explore how emotional states can shape movements by connecting the neural circuits for emotional processing to motor neural circuits. We first provide a comprehensive overview of the impact of different emotional states on motor control in humans and rodents. In line with behavioral studies, we set out to identify emotion-related structures capable of modulating motor output, behaviorally and anatomically. Neuronal circuits involved in emotional processing are extensively connected to the motor system. These circuits can drive emotional behavior, essential for survival, but can also continuously shape ongoing movement. In summary, the investigation of the intricate relationship between emotion and movement offers valuable insights into human behavior, including opportunities to enhance performance, and holds promise for improving mental and physical health. This review integrates findings from multiple scientific approaches, including anatomical tracing, circuit-based dissection, and behavioral studies, conducted in both animal and human subjects. By incorporating these different methodologies, we aim to present a comprehensive overview of the current understanding of the emotional modulation of movement in both physiological and pathological conditions.

Relationship between swimming speed, intra-cycle variation of horizontal speed, and Froude efficiency during consecutive stroke cycles in adolescent swimmers

The purpose of this study was to investigate the relationship between swimming speed, intra-cycle variation of horizontal speed of displacement (dv), and Froude efficiency (ηF) in front-crawl during three consecutive stroke cycles. The sample consisted of 15 boys aged 16.07 ± 0.77 years and 15 girls aged 15.05 ± 1.07 years. Swimming speed, dv and ηF were measured during a 25 m front-crawl trial. Three consecutive stroke cycles were measured. Swimming speed showed a non-significant stroke-by-stroke effect (F = 2.55, p = 0.087, η2 = 0.08), but a significant sex effect (F = 90.46, p < 0.001, η2 = 0.76). The dv and ηF had the same trend as the swimming speed for the stroke-by-stroke effect, but a non-significant sex effect (p > 0.05). The Spearman correlation matrix between swimming speed and dv, and swimming speed and ηF showed non-significant correlations for the three stroke cycles in both sexes. However, the tendency of the former was not always inverse, and the latter was not always direct. Coaches and swimmers need to be aware that lower dvs are not always associated with faster swimming speeds and vice-versa, and that ηF is a predictor of swimming speed, not dv.

State-dependent interhemispheric inhibition reveals individual differences in motor behavior in chronic stroke

OBJECTIVE

To investigate state-dependent interhemispheric inhibition (IHI) in chronic stroke survivors compared to neurotypical older adult controls, and test whether abnormal IHI modulation was associated with upper extremity motor behavior.

METHODS

Dual-coil transcranial magnetic stimulation (TMS) measured IHI bi-directionally, between non-lesioned and lesioned motor cortex (M1) in two activity states: (1) at rest and (2) during contralateral isometric hand muscle contraction. IHI was tested by delivering a conditioning stimulus 8-msec or 50-msec prior to a test stimulus over contralateral M1. Paretic motor behavior was assessed by clinical measures of impairment, strength, and dexterity, and mirroring activity in the non-paretic hand.

RESULTS

Stroke survivors demonstrated reduced IHI at rest, and less IHI modulation (active - rest) compared to controls. Individual differences in IHI modulation were related to motor behavior differences where greater IHI modulation was associated with greater motor impairment and more mirroring. In contrast, there were no relationships between IHI at rest and motor behavior.

CONCLUSIONS

Abnormal state-dependent interhemispheric circuit activity may be more sensitive to post-stroke motor deficits than when assessed in a single motor state.

SIGNIFICANCE

Characterizing state-dependent changes in neural circuitry may enhance models of stroke recovery and inform rehabilitation interventions.

Adopting a holistic focus of attention promotes adherence and improves performance in college track and field athletes

Research on novices suggests that an external focus improves performance over an internal focus. For experienced performers the results on attentional focus have been mixed. Recently Becker, Georges, and Aiken (2019) suggested that a holistic focus may be a useful substitute when an external focus is not appropriate. The purpose of this study was to investigate attentional focus within track and field athletes performing an underhand shot throw. 18 female athletes performed an underhand shot throw (4 kg) under three focus conditions: internal, external, and holistic. Participants also rated their adherence to each attentional focus manipulation. Repeated-measures ANOVAs with Sidak post-hoc were used to analyze both underhand shot throw distance and focus adherence. A significant main effect for condition was observed for distance (F = 6.14, p = .005). A holistic threw farther than an internal focus (p < .001) with no difference between internal and external (p = .380), or holistic and external foci (p = .312). For adherence, a significant main effect for condition was observed (F = 4.56, p = .018) with holistic focus adhering to the cue significantly more than internal focus (p < .019). The results of this study are in line with research that found a benefit for a holistic focus with novice performers (Becker et al., 2019). Mullen and Hardy (2010) also found a benefit for the golf putt, basketball shot, and long jump with skilled performers adopting a focus on the global or holistic aspect of the skill.

Genetic and environmental mouse models of autism reproduce the spectrum of the disease

Genetic and environmental factors increase autism spectrum disorder (ASD) incidence, and this has led to the generation of corresponding animal models, with some showing strong construct and face validity. This short review focuses on results we have recently obtained with environmental and genetic mouse models of ASD and that are the valproic acid, the poly I:C and the Shank 3 models. This has allowed us to provide a comparative description of these widely used animal models providing an interesting perspective as to the pros and cons of each one of them, in our experimental settings. In these papers, we focused on motor and gait disorders which are currently not included in the diagnosis criteria, but which may provide new insights to ASD pathophysiology potentially leading to innovative therapies for a disease that currently has none. In all these models, we reported behavioral, cellular and molecular alterations related to the cerebellum. Motor and gait deficits were observed to various degrees in animal models and, when strongly present, they were correlated to the severity of social deficits as well as to the number of cerebellar Purkinje cells. Additionally, we also reported that, like in humans, males are more severely affected than females in these ASD models. These findings, along with an increasing body of literature, open new hopes in the ASD field pointing to brain regions, such the cerebellum, that are at the crossroads between cognitive, social and motor deficits. Targeting these brain regions and their underlying pathways and synaptic connections may prove of significant benefits.

Association of Early Sports Practice with Cardiovascular Risk Factors in Community-Dwelling Adults: A Retrospective Epidemiological Study

BACKGROUND

Sports practice in childhood and adolescence has been inversely related to the chances of developing cardiovascular risk factors (CRFs). However, it is not clear whether sports practice in childhood and adolescence could be inversely related to CRF in adult life.

OBJECTIVES

This study aimed to analyze the association between early sports practice and cardiovascular risk factors in a randomized sample of community-dwelling adults.

METHODS

For this, 265 adults aged ≥ 18 years composed the sample. Cardiovascular risk factors of obesity, central obesity, diabetes, dyslipidemia, and hypertension were collected. Early sports practice was retrospectively self-reported using an appropriate instrument. Total physical activity level was assessed by accelerometry. The association between early sports practice and cardiovascular risk factors in adulthood was analyzed by binary logistic regression, adjusted for sex, age, socioeconomic status, and moderate-to-vigorous physical activity.

RESULTS

Early sports practice was observed in 56.2% of the sample. The prevalence of central obesity (31.5 vs. 50.0%; p = 0.003), diabetes (4.7% vs. 13.7%; p = 0.014), dyslipidemia (10.7% vs. 24.1%; p = 0.005), and hypertension (14.1% vs. 34.5%; p = 0.001) was lower in participants who reported early sports practice. Participants who reported early sports practice in childhood and adolescence were, respectively, 60% (OR = 0.40; 95% CI 0.19-0.82) and 59% (OR = 0.41; 95% CI 0.21-0.82) less likely to have hypertension in adult life when compared to those with no early sports practice, independently of sex, age, socioeconomic status, and habitual physical activity level in adulthood.

CONCLUSION

Early sports practice in childhood and adolescence was a protective factor for hypertension in adulthood.

The development of hand, foot, trunk, hearing, and visual lateral preference throughout the lifespan

This research investigated the developmental process of five lateral preference dimensions (hand, foot, trunk, hearing, and visual preference). A total of 1236 volunteers participated in this study, divided into five age groups: 07-12 (n = 247); 13-17 (n = 234); 18-30 (n = 227); 31-60 (n = 225); and 61-90 years old (n = 303). Lateral preference was assessed via questionnaire with the Global Lateral Preference Inventory. By assessing the degree and direction of lateral preference in different ages, our results revealed a pattern of lateralization strengthening with aging in all the analyzed dimensions. We also verified significant correlation between hand preference and the other dimensions for all age groups, but correlation was stronger in the 7-12 group for all correlation pairs. Our results lead to the suggestion of an underlying general lateralization process in early ages (7-12 years old) followed by specific developmental trajectories of each preference dimension (13 years forward), likely startled by hemisphere and functional specialization related to innate developmental patterns of neural structures and social/environmental influences.

Promoting Positive Health Outcomes in an Urban Community-Based Physical Activity Intervention for Preschool Aged Children on the Autism Spectrum

While there is wide consensus regarding the importance of early intervention, health is rarely considered within priorities. Twenty-five children on the autism spectrum (M_age = 4.67, SD = 0.82) participated in a 12-week physical activity intervention. Primary objective was to examine impact of a physical activity intervention on physical activity, fitness and motor competence. Secondary objective was to examine associations between motor behavior and ASD symptoms. Ball skills (p < .001) and isometric push-up performance (p = .02) improved. Autism symptoms were associated with motor skills (r > -  .49, p < .05). Study outcomes provide new knowledge regarding design, delivery, and measures for early interventions targeting health disparities in young children on the autism spectrum.

Electromyography as a Method for Distinguishing Dystonia in Mice

Electromyography (EMG) methods allow quantitative analyses of motor function. The techniques include intramuscular recordings that are performed in vivo. However, recording muscle activity in freely moving mice, particularly in models of motor disease, often creates challenges that prevent the acquisition of clean signals. Recording preparations must be stable enough for the experimenter to collect an adequate number of signals for statistical analyses. Instability results in a low signal-to-noise ratio that prohibits proper isolation of EMG signals from the target muscle during the behavior of interest. Such insufficient isolation prevents the analysis of full electrical potential waveforms. In this case, resolving the shape of a waveform to differentiate individual spikes and bursts of muscle activity can be difficult. A common source of instability is an inadequate surgery. Poor surgical techniques cause blood loss, tissue damage, poor healing, encumbered movement, and unstable implantation of the electrodes. Here, we describe an optimized surgical procedure that ensures electrode stability for in vivo muscle recordings. We implement our technique to obtain recordings from agonist and antagonist muscle pairs in the hindlimbs of freely moving adult mice. We validate the stability of our method by holding EMG recordings during dystonic behavior. Our approach is ideal for studying normal and abnormal motor function in actively behaving mice and valuable for recording intramuscular activity when considerable motion is expected.

Decabromodiphenyl ethane induced hyperactivity in developing zebrafish at environmentally relevant concentrations

Decabromodiphenyl ethane (DBDPE), a widely used novel brominated flame retardant, is gaining concerns due to rapidly increased contents in various environmental and biota samples. In the present study, zebrafish (Danio rerio) embryos were exposed to 2.91, 9.71, 29.14 and 97.12 μg/L of DBDPE until 120 h post-fertilization (hpf) to investigate the potential developmental neurotoxicity and underlying mechanisms. Chemical analysis revealed concentration-dependently increased body burdens of DBDPE in zebrafish larvae, with bioaccumulation factors (BCFs) ranging from 414 to 726. Embryonic exposure to DBDPE caused hyperactivity without affecting the development of secondary motoneuron axons and muscle fibers. However, further results implicated that DBDPE may affect the locomotor regulatory network via different mechanisms at lower and higher concentrations. On the one hand, embryonic exposure to 2.91 μg/L DBDPE transiently promoted spontaneous coiling contractions, but showed no effects on touch-response and swimming activity in zebrafish larvae. The whole-body contents of neurotransmitters were significantly decreased. Significant decreased protein abundances of α1-TUBULIN and SYN2a and molecular docking results pointed out possible interactions of DBDPE with these two proteins. However, these changes may be unconcerned with the transient hyperactivity, and the exact molecular mechanisms need further investigation. On the other hand, 29.14 and 97.12 μg/L DBDPE exposure caused longer-lasting effects in promoting spontaneous coiling contractions, and also touch-response and swimming activity. At the same time, increased ACh contents (without changes of other neurotransmitters) and ChAT activity and inhibited transcription of nAChRs were observed at higher concentrations. Molecular docking indicated direct interaction of DBDPE with ChAT. The results suggested that DBDPE induced hyperactivity at higher concentrations was probably involved with disrupted cholinergic system, with ChAT as a potential target. Given that the body burden of DBDPE in lower concentration group was comparable with those detected in wild fish, the current results may provide useful information for ecological risk assessment.

Hyperactivity of Purkinje cell and motor deficits in C9orf72 knockout mice

A hexanucleotide (GGGGCC) repeat expansion in the first intron of the C9ORF72 gene is the most frequently reported genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The cerebellum has not traditionally been thought to be involved in the pathogenesis of C9ORF72-associated ALS/FTD, but recent evidence suggested a potential role. C9ORF72 is highly expressed in the cerebellum. Decreased C9ORF72 transcript and protein levels were detected in the postmortem cerebellum, suggesting a loss-of-function effect of C9ORF72 mutation. This study investigated the role of loss of C9ORF72 function using a C9orf72 knockout mouse line. C9orf72 deficiency led to motor impairment in rotarod, beam-walking, paw-print, open-field, and grip-strength tests. Purkinje cells are the sole output neurons in the cerebellum, and we next determined their involvement in the motor phenotypes. We found hyperactivity of Purkinje cells in the C9orf72 knockout mouse accompanied by a significant increase of the large-conductance calcium-activated potassium channel (BK) protein in the cerebellum. The link between BK and Purkinje cell firing was demonstrated by the acute application of the BK activator that increased the firing frequency of the Purkinje cells ex vivo. In vivo chemogenetic activation of Purkinje cells in wild-type mice led to similar motor deficits in rotarod and beam-walking tests. Our results highlight that C9ORF72 loss alters the activity of the Purkinje cell and potentially the pathogenesis of the disease. Manipulating the Purkinje cell firing or cerebellar output may contribute to C9ORF72-associated ALS/FTD treatment.

Association of pain-related threat beliefs and disability with postural control and trunk motion in individuals with low back pain: a systematic review and meta-analysis

PURPOSE

Low back pain (LBP) individuals with high levels of fear of pain might display changes in motor behavior, which leads to disability. This study aimed to systematically review the influence of pain-related threat beliefs or disability on trunk kinematic or postural control in LBP.

METHOD

Eight electronic databases were searched from January 1990 to July 1, 2020. Meta-analysis using random-effect model was performed for 18 studies on the association between pain-related threat beliefs or disability and lumbar range of motion. Pearson r correlations were used as the effect size.

RESULT

Negative correlations were observed between lumbar range of motion (ROM) and pain-related threat beliefs (r = - 0.31, p < 0.01, 95% CI: - 0.39, - 0.24) and disability (r =  - 0.24, p < 0.01, 95% CI: - 0.40, - 0.21). Nonsignificant correlations were reported between pain-related threat beliefs and center of pressure parameters during static standing in 75% of the studies. In 33% of the studies, moderate negative correlations between disability and postural control were observed.

CONCLUSION

Motor behaviors are influenced by several factors, and therefore, the relatively weak associations observed between reduced lumbar ROM with higher pain-related threat beliefs and perceived disability, and postural control with disability are to be expected. This could aid clinicians in the assessment and planning rehabilitation interventions.

LEVEL OF EVIDENCE I

Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Neuroprotective Effect of Riboflavin Producing Lactic Acid Bacteria in Parkinsonian Models

Oxidative stress and inflammatory processes might contribute to the cascade of events leading Parkinson disease (PD); and vitamins such as riboflavin can exert protection on vulnerable neurons in neurodegenerative conditions. Previously, it was demonstrated that a mixture of lactic acid bacteria (including a riboflavin-producing strain) improved motor skills in a parkinsonian model. The aim of the present work was to investigate the neuroprotective potential of Lactiplantibacillus (L.) plantarum CRL2130, a riboflavin-producing strain in PD models. In vitro, N2a differentiated neurons were exposed the neurotoxin 1-methyl-4-phenylpyridinium (MPP+) and treated with intracellular bacterial extracts or commercial riboflavin. In vivo, adult male C57BL/6 mice were injected with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and probenecid, and received orally L. plantarum CRL2130, L. plantarum CRL725 (parent strain that produces low levels of riboflavin) or commercial vitamin. Results showed that when N2a cells were incubated with intracellular extract from L. plantarum CRL2130 maintained the viability, and significantly decreased the release of IL-6 and the formation of reactive oxygen species (ROS), all affected by MPP+. In vivo, the administration of L. plantarum CRL2130 attenuated motor deficits and prevented dopaminergic neuronal death. Decrease of pro-inflammatory cytokines and increase of IL-10 in both serum and brain were observed in samples from mice that received L. plantarum CRL2130 compared to MPTP control group (without treatment). In addition, these beneficial effects were similar or improved when compared with animals that received commercial riboflavin. In conclusion, L. plantarum CRL2130 showed a neuroprotective effect in both PD models through anti-oxidant/anti-inflammatory mechanisms.

Sedentary behavior is associated with musculoskeletal pain in adolescents: A cross sectional study

BACKGROUND

High prevalence of back pain has been observed in adolescents. Sedentary behavior (SB) is considered a risk factor for musculoskeletal pain. The association between back pain and SB in the pediatric/adolescent population is not well established.

OBJECTIVE

To investigate the association between SB and low back and neck pain in adolescents according to sex.

METHODS

This is a cross-sectional study with children and adolescents aged 10-17 years, randomly recruited from public and private schools in Presidente Prudente, Brazil. All students enrolled in the selected schools were eligible to participate. SB was evaluated by adding the number of hours of use of screen devices, such as television, computer, video game, and smartphone/tablet. To assess neck and low back pain, the Nordic Musculoskeletal Questionnaire was used. Physical activity and socioeconomic status were assessed by the Baecke Questionnaire and the Brazilian Criteria for Economic Classification (ABEP), respectively. Odds ratio (OR) from Binary Logistic Regression in the unadjusted and adjusted model (physical activity, abdominal obesity, and socioeconomic status) showed the relationship between musculoskeletal pain and SB.

RESULTS

A total of 1011 adolescents (557 girls) with a mean ± standard deviation age of 13.2±2.4 years were included. Moderate (OR = 1.80; 95%CI: 1.00, 3.23) and high (OR = 1.91; 95%CI: 1.02, 3.53) SB were associated with neck pain in girls. In boys, moderate SB [OR = 2.75; 95%CI: 1.31, 5.78) were associated with neck pain. Moderate (OR = 2.73; 95%CI: 1.45, 5.02) and high (OR = 2.49; 95%CI: 1.30, 4.76) SB were associated with low back pain only in girls.

CONCLUSION

Moderate and high SB were associated with neck pain in girls and boys, while moderate and high SB were associated with low back pain only in girls.

Knockdown of Astrocytic Monocarboxylate Transporter 4 in the Motor Cortex Leads to Loss of Dendritic Spines and a Deficit in Motor Learning

Monocarboxylate transporters (MCTs) shuttle molecules, including L-lactate, involved in metabolism and cell signaling of the central nervous system. Astrocyte-specific MCT4 is a key component of the astrocyte-neuron lactate shuttle (ANLS) and is important for neuroplasticity and learning of the hippocampus. However, the importance of astrocyte-specific MCT4 in neuroplasticity of the M1 primary motor cortex remains unknown. In this study, we investigated astrocyte-specific MCT4 in motor learning and neuroplasticity of the M1 primary motor cortex using a cell-type specific shRNA knockdown of MCT4. Knockdown of astrocyte-specific MCT4 resulted in impaired motor performance and learning on the accelerating rotarod. In addition, MCT4 knockdown was associated with a reduction of neuronal dendritic spine density and spine width and decreased protein expression of PSD95, Arc, and cFos. Using near-infrared-conjugated 2-deoxyglucose uptake as a surrogate marker for neuronal activity, MCT4 knockdown was also associated with decreased neuronal activity in the M1 primary motor cortex and associated motor regions including the dorsal striatum and ventral thalamus. Our study supports a potential role for astrocyte-specific MCT4 and the ANLS in the neuroplasticity of the M1 primary motor cortex. Targeting MCT4 may serve to enhance neuroplasticity and motor repair in several neurological disorders, including Parkinson's disease and stroke.

Effect of Different Sports Practice on Sleep Quality and Quality of Life in Children and Adolescents: Randomized Clinical Trial

Background

Sports practice can promote several health benefits in pediatric populations; nonetheless, most of the studies that investigated these benefits are of cross-sectional design. Thus, our objective was to verify the effectiveness of two types of physical activities through sports, judo and ball games (soccer, volleyball, handball, and basketball) on the quality of sleep and life of Brazilian children and adolescents.

Methods

The study is a randomized clinical trial, conducted with 65 participants of both sexes (6–15 years old) in a philanthropic institution in Brazil. The variables investigated were the quality of sleep and life, using the mini-sleep questionnaire and KidsCreen-52 questionnaires (this instrument has a scale ranging from 0 to 100, where 100 is the best value for each domain), respectively. The interventions carried out during 12 weeks (twice a week) were judo and ball games. In the statistical analysis, analysis of variance (ANOVA) for repeated measures was used and the level of statistical significance used was 5%.

Results

Judo (P = 0.032) and ball games (P = 0.005) contributed to improving the quality of sleep in the participants. Considering the score of the domains of quality of life, judo and ball games significantly increased the perception of health and physical activity [mean = 6.9 (8.3%) and 8.91 (12.2%) points, respectively], autonomy [mean = 5.81 (7.3%) and 5.00 (6.9%) points], friends and social support (mean = 2.83 (3.8%) and 12.00 (15.9%) points), provocation and bullying [mean = 10.21 (18.1%) and 2.14 (4.1%) points].

Conclusion

It is concluded that both judo and ball games brought benefits to the quality of sleep and life of children and adolescents. Health promotion actions should encourage the increase in sports practice in children and adolescents to improve sleep and quality of life.

Complex motion series performance differs between previously untreated patients with Parkinson's disease and controls

Motor behaviour in patients with Parkinson's disease is determined with instrumental tests and rating procedures. Results mirror impairment of an individual patient. Objectives were to determine the associations between two kinds of motion series and rating scores in previously untreated 64 patients and to compare outcomes to controls. The line tracing task asks to follow a given path. It measures the needed interval, the number and duration of contacts to the path. The aiming procedure asks to hit contact plates with a pencil and determines the needed time period and the number of accurate, respectively, missed key strokes. Both tests differed between patients and controls. The line tracing task was more sensitive. The line tracing task asks for a complex motion series performance with more cognitive load. The aiming task prompts for a conduction of preponderant simple, repetitive movement series. Only initially, a complex process of aiming is necessary. Performance of complex motion sequences better differs between patients with Parkinson's disease and controls than conduction of simple, repetitive movement series.

Early movement restriction deteriorates motor function and soleus muscle physiology

Children with low physical activity and interactions with environment experience atypical sensorimotor development and maturation leading to anatomical and functional disorganization of the sensorimotor circuitry and also to enduring altered motor function. Previous data have shown that postnatal movement restriction in rats results in locomotor disturbances, functional disorganization and hyperexcitability of the hind limb representations in the somatosensory and motor cortices, without apparent brain damage. Due to the reciprocal interplay between the nervous system and muscle, it is difficult to determine whether muscle alteration is the cause or the result of the altered sensorimotor behavior (Canu et al., 2019). In the present paper, our objectives were to evaluate the impact of early movement restriction leading to sensorimotor restriction (SMR) during development on the postural soleus muscle and on sensorimotor performance in rats, and to determine whether changes were reversed when typical activity was resumed. Rats were submitted to SMR by hind limb immobilization for 16 h / day from birth to postnatal day 28 (PND28). In situ isometric contractile properties of soleus muscle, fiber cross sectional area (CSA) and myosin heavy chain content (MHC) were studied at PND28 and PND60. In addition, the motor function was evaluated weekly from PND28 to PND60. At PND28, SMR rats presented a severe atrophy of soleus muscle, a decrease in CSA and a force loss. The muscle maturation appeared delayed, with persistence of neonatal forms of MHC. Changes in kinetic properties were moderate or absent. The Hoffmann reflex provided evidence for spinal hyperreflexia and signs of spasticity. Most changes were reversed at PND60, except muscle atrophy. Functional motor tests that require a good limb coordination, i.e. rotarod and locomotion, showed an enduring alteration related to SMR, even after one month of 'typical' activity. On the other hand, paw withdrawal test and grip test were poorly affected by SMR whereas spontaneous locomotor activity increased over time. Our results support the idea that proprioceptive feedback is at least as important as the amount of motor activity to promote a typical development of motor function. A better knowledge of the interplay between hypoactivity, muscle properties and central motor commands may offer therapeutic perspectives for children suffering from neurodevelopmental disorders.

Predicting motor behavior: an efficient EEG signal processing pipeline to detect brain states with potential therapeutic relevance for VR-based neurorehabilitation

Virtual reality (VR)-based motor therapy is an emerging approach in neurorehabilitation. The combination of VR with electroencephalography (EEG) presents further opportunities to improve therapeutic efficacy by personalizing the paradigm. Specifically, the idea is to synchronize the choice and timing of stimuli in the perceived virtual world with fluctuating brain states relevant to motor behavior. Here, we present an open source EEG single-trial based classification pipeline that is designed to identify ongoing brain states predictive of the planning and execution of movements. 9 healthy volunteers each performed 1080 trials of a repetitive reaching task with an implicit two-alternative forced choice, i.e., use of the right or left hand, in response to the appearance of a visual target. The performance of the EEG decoding pipeline was assessed with respect to classification accuracy of right vs. left arm use, based on the EEG signal at the time of the stimulus. Different features, feature extraction methods, and classifiers were compared at different time windows; the number and location of informative EEG channels and the number of calibration trials needed were also quantified, as well as any benefits from individual-level optimization of pipeline parameters. This resulted in a set of recommended parameters that achieved an average 83.3% correct prediction on never-before-seen testing data, and a state-of-the-art 77.1% in a real-time simulation. Neurophysiological plausibility of the resulting classifiers was assessed by time-frequency and event-related potential analyses, as well as by Independent Component Analysis topographies and cortical source localization. We expect that this pipeline will facilitate the identification of relevant brain states as prospective therapeutic targets in closed-loop EEG-VR motor neurorehabilitation.

Motor Skill Differences in Autism Spectrum Disorder: a Clinically Focused Review

PURPOSE OF REVIEW

This review synthesizes recent, clinically relevant findings on the scope, significance, and centrality of motor skill differences in autism spectrum disorder (ASD).

RECENT FINDINGS

Motor challenges in ASD are pervasive, clinically meaningful, and highly underrecognized, with up to 87% of the autistic population affected but only a small percentage receiving motor-focused clinical care. Across development, motor differences are associated with both core autism symptoms and broader functioning, though the precise nature of those associations and the specificity of motor profiles to ASD remain unestablished. Findings suggest that motor difficulties in ASD are quantifiable and treatable, and that detection and intervention efforts targeting motor function may also positively influence social communication. Recent evidence supports a need for explicit recognition of motor impairment within the diagnostic framework of ASD as a clinical specifier. Motor differences in ASD warrant greater clinical attention and routine incorporation into screening, evaluation, and treatment planning.

Neurotoxicity of fipronil affects sensory and motor systems in zebrafish

Fipronil is a phenylpyrazole insecticide that may selectively inhibit gamma-aminobutyric acid receptors in insects. Although fipronil is the most widely used insecticide in aquatic environments, few studies have evaluated its neurotoxicity for the sensory and motor systems of aquatic vertebrates. We assessed the effects of acute fipronil exposure on the survival rate, number of hair cells of lateral lines, and neurotoxicity for zebrafish (Danio rerio). In addition, heat maps and the speed and distance of the swimming trajectory were compared between zebrafish subjected to the sham and fipronil treatments. Western blotting and immunohistochemistry were conducted separately to compare expressions of oxidative stress, inflammation, apoptosis, and neurotoxicity related proteins in the brain tissue between adult zebrafish with sham and fipronil treatments. Our results indicated that the survival rates and the speed and distance of the swimming trajectory significantly decreased for adult zebrafish exposed to fipronil. The results also suggested that the number of hair cells of lateral lines significantly reduced for zebrafish embryos exposed to fipronil. In histopathology and Western blotting tests, substantial oxidative stress, inflammation, and apoptosis were observed in the brain tissue of adult zebrafish exposed to fipronil. Our results revealed that fipronil toxicity may impair sensory and motor systems in zebrafish because of damage to lateral hair cells and brain tissue through oxidative stress, inflammation, and apoptosis, which in turn result in a significantly reduced survival rate and impaired locomotion. The behavioral responses of zebrafish exposed to fipronil toxicity should be determined for better understanding the reliability of behavioral biomarkers in the risk assessment of environmental toxicology.

Dissociation of genotype-dependent cognitive and motor behavior in a strain of aging mice devoid of the prion protein

The prion glycoprotein (PrP^C) is highly expressed in the nervous system as well as in other organs. Its functional roles in behavior have been examined mainly in non co-isogenic, wild-type and PrP^C-deficient mice, which showed both age- and genotype-dependent differences. In general, however, effects of genetic background upon behavioral tests are mostly unclear when applied to aging rodents. The present study aimed to determine the effect of deletion of the prion protein on behavior of isogenic mice across different ages. We disclosed a genotype-dependent behavioral dissociation between either motor or cognitive tests, as a function of both age and test type. Remarkably, we also detected a clear age- and genotype-dependent difference in the variability of performance in a cognitive test. The current findings are relevant for both the interpretation of PrP^C-related behavior, as well as for issues of reproducibility in studies of rodent behavior.

Cannabinoid CB2 receptors are expressed in glutamate neurons in the red nucleus and functionally modulate motor behavior in mice

Cannabinoids produce a number of central nervous system effects via the CB2 receptor (CB2R), including analgesia, antianxiety, anti-reward, hypoactivity and attenuation of opioid-induced respiratory depression. However, the cellular distributions of the CB2Rs in the brain remain unclear. We have reported that CB2Rs are expressed in midbrain dopamine (DA) neurons and functionally regulate DA-mediated behavior(s). Unexpectedly, high densities of CB2-like signaling were also found in a neighboring motor structure - the red nucleus (RN) of the midbrain. In the present study, we systematically explored CB2R expression and function in the RN. Immunohistochemistry and in situ hybridization assays showed high densities of CB2R-immunostaining and mRNA signal in RN magnocellular glutamate neurons in wildtype and CB1-knockout, but not CB2-knockout, mice. Ex vivo electrophysiological recordings in midbrain slices demonstrated that CB2R activation by JWH133 dose-dependently inhibited firing rates of RN magnocellular neurons in wildtype, but not CB2-knockout, mice, while having no effect on RN GABA neurons in transgenic GAD67-GFP reporter mice, suggesting CB2-mediated effects on glutamatergic neurons. In addition, microinjection of JWH133 into the RN produced robust ipsilateral rotations in wildtype, but not CB2-knockout mice, which was blocked by pretreatment with either a CB2 or DA D1 or D2 receptor antagonist, suggesting a DA-dependent effect. Finally, fluorescent tract tracing revealed glutamatergic projections from the RN to multiple brain areas including the ventral tegmental area, thalamus, and cerebellum. These findings suggest that CB2Rs in RN glutamate neurons functionally modulate motor activity, and therefore, constitute a new target in cannabis-based medication development for motor disorders.

Titanium dioxide nanoparticle affects motor behavior, neurodevelopment and axonal growth in zebrafish (Danio rerio) larvae

More attention has been recently paid to the ecotoxicity of titanium dioxide nanoparticles (nano-TiO₂) owing to its common use in many fields. Although previous studies have shown that nano-TiO₂ is neurotoxic, the mechanism is still largely unknown. In the present study, zebrafish embryos were exposed to 0.01, 0.1, and 1.0 mg/L nano-TiO₂ and 1.0 mg/L micro-TiO₂ for up to 6 days post-fertilization (dpf). Exposure to 1.0 mg/L nano-TiO₂ significantly decreased the body length and weight of zebrafish larvae; however, the hatching and mortality rate of zebrafish embryos did not change. Behavioral tests showed that nano-TiO₂ exposure significantly reduced the swimming speed and clockwise rotation times of the larvae. The results revealed that nano-TiO₂ treatment adversely affected motor neuron axon length in Tg (hb9-GFP) zebrafish and decreased central nervous system (CNS) neurogenesis in Tg (HuC-GFP) zebrafish. Additionally, real-time polymerase chain reaction analysis demonstrated that genes associated with neurogenesis (nrd and elavl3) and axonal growth (α1-tubulin, mbp, and gap43) were significantly affected by nano-TiO₂ exposure. In conclusion, our study demonstrated that early-life stage exposure of zebrafish to nano-TiO₂ causes adverse neural outcomes through the inhibition of neurodevelopment and motor neuron axonal growth.

Serotonergic control of the glutamatergic neurons of the subthalamic nucleus

The subthalamic nucleus (STN) houses a dense cluster of glutamatergic neurons that play a central role in the functional dynamics of the basal ganglia, a group of subcortical structures involved in the control of motor behaviors. Numerous anatomical, electrophysiological, neurochemical and behavioral studies have reported that serotonergic neurons from the midbrain raphe nuclei modulate the activity of STN neurons. Here, we describe this serotonergic innervation and the nature of the regulation exerted by serotonin (5-hydroxytryptamine, 5-HT) on STN neuron activity. This regulation can occur either directly within the STN or at distal sites, including other structures of the basal ganglia or cortex. The effect of 5-HT on STN neuronal activity involves several 5-HT receptor subtypes, including 5-HT_1A, 5-HT_1B, 5-HT_2C and 5-HT₄ receptors, which have garnered the highest attention on this topic. The multiple regulatory effects exerted by 5-HT are thought to be modified under pathological conditions, altering the activity of the STN, or due to the benefits and side effects of treatments used for Parkinson's disease, notably the dopamine precursor l-DOPA and high-frequency STN stimulation. Originally understood as a motor center, the STN is also associated with decision making and participates in mood regulation and cognitive performance, two domains of personality that are also regulated by 5-HT. The literature concerning the link between 5-HT and STN is already important, and the functional overlap is evident, but this link is still not entirely understood. The understanding of this link between 5-HT and STN should be increased due to the possible importance of this regulation in the control of fronto-STN loops and inherent motor and non-motor behaviors.

Maternal stress programs accelerated aging of the basal ganglia motor system in offspring

Early-life stress involved in the programming of stress-related illnesses can have a toxic influence on the functioning of the nigrostriatal motor system during aging. We examined the effects of perinatal stress (PRS) on the neurochemical, electrophysiological, histological, neuroimaging, and behavioral correlates of striatal motor function in adult (4 months of age) and old (21 months of age) male rats. Adult PRS offspring rats showed reduced dopamine (DA) release in the striatum associated with reductions in tyrosine hydroxylase-positive (TH⁺) cells and DA transporter (DAT) levels, with no loss of striatal dopaminergic terminals as assessed by positron emission tomography analysis with fluorine-18-l-dihydroxyphenylalanine. Striatal levels of DA and its metabolites were increased in PRS rats. In contrast, D₂ DA receptor signaling was reduced and A_2A adenosine receptor signaling was increased in the striatum of adult PRS rats. This indicated enhanced activity of the indirect pathway of the basal ganglia motor circuit. Adult PRS rats also showed poorer performance in the grip strength test and motor learning tasks. The aged PRS rats also showed a persistent reduction in striatal DA release and defective motor skills in the pasta matrix and ladder rung walking tests. In addition, the old rats showed large increases in the levels of SNAP-25 and synaptophysin, which are synaptic vesicle-related proteins in the striatum, and in the PRS group only, reductions in Syntaxin-1 and Rab3a protein levels were observed. Our findings indicated that the age-dependent threshold for motor dysfunction was lowered in PRS rats. This area of research is underdeveloped, and our study suggests that early-life stress can contribute to an increased understanding of how aging diseases are programmed in early-life.

Phenotypic evaluation of a childhood-onset parkinsonism-dystonia mouse model with inherent postural abnormalities

Mouse models that replicate facets of human neurological diseases are often used at the pre-clinical stage to better understand the underlying mechanisms of a disease and test the target engagement of potential therapeutic interventions. We recently characterized a mouse model of childhood-onset parkinsonism-dystonia, a disease caused by a homozygous loss-of-function mutation in the SLC39A14 gene. The disease manifests itself phenotypically by impairments in locomotor behaviour and postural abnormalities. Our initial characterization of the model revealed that the Slc39a14^-/- mice showed altered Mn homeostasis and compromised locomotor performance in vertical pole-descending, horizontal beam-traversing, and rotarod tests (Jenkitkasemwong et al., 2018). However, some of the mice also displayed torticollis and Straub tail. In this study, we investigated whether these postural abnormalities affected the performance in the above motility tests and consequently, biased and compromised the external validity of reported abnormal locomotor profiles. Our analyses showed that the Slc39a14^-/- mice displaying torticollis and/or Straub tail had tests scores comparable to scores of their counterparts that never displayed these postural abnormalities. The z-score general index of performance revealed that the Slc39a14^-/- model presents a complex pathological motor phenotype relevant to the complexity of phenotypes identified in childhood-onset parkinsonism-dystonia.

Effects of repetitive hyperbaric oxygen therapy on neuroprotection in middle cerebral artery occlusion rats

Hyperbaric oxygen (HBO) has been suggested as a possible therapy for brain injury. However, the effects of HBO after transient brain ischemia are inconsistent and the underlying mechanisms are not fully known. The present study aimed to investigate the effects of repetitive HBO intervention in a transient middle cerebral artery occlusion (MCAO) animal model. Seventy-two Sprague-Dawley rats received MCAO and were randomly assigned to normal air control or HBO intervention groups. Each group was divided into 3 subgroups according to the intervention time period (7, 14, and 21 days). HBO was started 24 h post-MCAO for 1 h/day at 3.0 ATA with no-air breaks. After the final intervention, half of the rats in each subgroup were sacrificed and the right motor cortex was removed to examine levels of Akt phosphorylation and glutathione (GSH), as well as glutathione peroxidase (GPx) and reductase (GR) activity. The other half of the rats were used to examine infarct volume. At 24 h post-MCAO and the end of the final intervention, rats underwent tests to examine motor performance. We noted that 14- and 21-day HBO interventions significantly reduced infarct volume and increased Akt phosphorylation and GSH levels and GPx and GR activity. Motor performance was also significantly improved after 14- and 21-day interventions. No significant differences were observed between the controls and 7-day intervention groups. Repetitive HBO intervention starting 24 h post-MCAO and applied for at least 14 days, provided neuroprotective effects through modulating the cell survival pathway and antioxidative defense system.

The macrocyclic lactones ivermectin and moxidectin show differential effects on rotational behavior in the 6-hydroxydopamine mouse model of Parkinson's disease

Parkinson's disease (PD) is a common neurodegenerative disease characterized by motor and cognitive deficits, the result of dopamine (DA)-depletion within the basal ganglia. Currently, DA replacement therapy in the form of Sinemet (L-DOPA plus Carbidopa) provides symptomatic motor benefits and remains the "gold standard" for treatment. Several pharmacological approaches can enhance DA neurotransmission including the administration of DA receptor agonists, the inhibition of DA metabolism, and enhancing pre-synaptic DA release. DA neurotransmission is regulated by several receptor subtypes including signaling through the purinergic system. P2 × 4 receptors (P2 × 4Rs) are a class of cation-permeable ligand-gated ion channels activated by the synaptic release of extracellular adenosine 5'-triphosphate (ATP). P2 × 4Rs are expressed throughout the central nervous system including the dopaminergic circuitry of the substantia nigra, basal ganglia, and related reward networks. Previous studies have demonstrated that P2 × 4Rs can modulate several DA-dependent characteristics including motor, cognitive, and reward behaviors. Ivermectin (IVM) and moxidectin (MOX) are two macrocyclic lactones that can potentiate P2 × 4Rs. In this study, we sought to investigate the role of P2 × 4Rs in mediating DA neurotransmission by exploring their impact on DA-dependent behavior, specifically rotation frequency in the unilateral 6-hydroxydopamine-lesioned mouse model of DA-depletion. While we did not observe any differences in the degree of lesioning based on immunostaining for tyrosine hydroxylase between sexes, male mice displayed a greater number of rotations with L-DOPA compared to female mice. In contrast, we observed that IVM plus L-DOPA increased the number of rotations (per 10 min) in female, but not male mice. These findings highlight the potential role of pharmacologically targeting the purinergic receptor system in modulating DA neurotransmission as well as the importance of sex differences impacting outcome measures.

Levodopa improves handwriting and instrumental tasks in previously treated patients with Parkinson's disease

Motor symptoms in patients with Parkinson's disease may be determined with instrumental tests and rating procedures. Their outcomes reflect the functioning and the impairment of the individual patient when patients are tested off and on dopamine substituting drugs. Objectives were to investigate whether the execution speed of a handwriting task, instrumentally assessed fine motor behavior, and rating scores improve after soluble levodopa application. 38 right-handed patients were taken off their regular drug therapy for at least 12 h before scoring, handwriting, and performance of instrumental devices before and 1 h after 100 mg levodopa intake. The outcomes of all performed procedures improved. The easy-to-perform handwriting task and the instrumental tests demand for fast and precise execution of movement sequences with considerable cognitive load in the domains' attention and concentration. These investigations may serve as additional tools for the testing of the dopaminergic response.

Apolipoprotein D-mediated preservation of lysosomal function promotes cell survival and delays motor impairment in Niemann-Pick type A disease

Lysosomal Storage Diseases (LSD) are genetic diseases causing systemic and nervous system dysfunction. The glia-derived lipid binding protein Apolipoprotein D (ApoD) is required for lysosomal functional integrity in glial and neuronal cells, ensuring cell survival upon oxidative stress or injury. Here we test whether ApoD counteracts the pathogenic consequences of a LSD, Niemann Pick-type-A disease (NPA), where mutations in the acid sphingomyelinase gene result in sphingomyelin accumulation, lysosomal permeabilization and early-onset neurodegeneration. We performed a multivariable analysis of behavioral, cellular and molecular outputs in 12 and 24 week-old male and female NPA model mice, combined with ApoD loss-of-function mutation. Lack of ApoD in NPA mice accelerates cerebellar-dependent motor deficits, enhancing loss of Purkinje neurons. We studied ApoD expression in brain sections from a NPA patient and age-matched control, and the functional consequences of ApoD supplementation in primary human fibroblasts from two independent NPA patients and two control subjects. Cell viability, lipid peroxidation, and lysosomal functional integrity (pH, Cathepsin B activity, Galectin-3 exclusion) were examined. ApoD is endogenously overexpressed in NPA patients and NPA mouse brains and targeted to lysosomes of NPA patient cells, including Purkinje neurons and cultured fibroblasts. The accelerated lysosomal targeting of ApoD by oxidative stress is hindered in NPA fibroblasts, contributing to NPA lysosomes vulnerability. Exogenously added ApoD reduces NPA-prompted lysosomal permeabilization and alkalinization, reverts lipid peroxides accumulation, and significantly increases NPA cell survival. ApoD administered simultaneously to sphingomyelin overload results in complete rescue of cell survival. Our results reveal that ApoD protection of lysosomal integrity counteracts NPA pathology. ApoD supplementation could significantly delay not only the progression of NPA disease, but also of other LSDs through its beneficial effects in lysosomal functional maintenance.

Real-time visual feedback reduces patellofemoral joint forces during squatting in individuals with patellofemoral pain

BACKGROUND

Elevated patellofemoral joint forces appear to contribute to the development of patellofemoral pain. As a result, treatment of patellofemoral pain often includes movement retraining intended to reduce patellofemoral joint forces. Real-time visual feedback has been shown to be effective for retraining running kinematics; however, we are not aware of a previous study that has examined the influence of real-time visual feedback on patellofemoral joint mechanics during a squat.

METHODS

Twenty individuals with patellofemoral pain completed squats before (baseline) and immediately after (post-feedback) completing a real-time visual feedback training session. During the session, participants received visual feedback related to their patellofemoral joint forces (estimated via a musculoskeletal model) during squatting and were asked to alter their movement pattern to minimize these forces. Patellofemoral joint forces and hip, knee, and ankle joint mechanics were compared for the baseline and post-feedback trials in order to examine how feedback influenced squat performance.

FINDINGS

Participants demonstrated a 14.4% reduction in patellofemoral joint forces following the feedback session. They appeared to achieve this reduction in patellofemoral joint forces by squatting with less knee flexion (97.26 ± 17.11° vs. 102.96 ± 16.55°) and lower knee extension moments (0.10 ± 0.02 Nm/bodyweight vs. 0.11 ± 0.02 Nm/bodyweight) and quadriceps forces (4.06 ± 0.87 bodyweights vs. 4.67 ± 0.98 bodyweights).

INTERPRETATION

Real-time visual feedback appears to be effective for reducing patellofemoral joint forces during squatting in individuals with patellofemoral pain. As a result, training of this nature may be beneficial when treating patellofemoral pain.

Absence of Glia Maturation Factor Protects from Axonal Injury and Motor Behavioral Impairments after Traumatic Brain Injury

Traumatic brain injury (TBI) causes disability and death, accelerating the progression towards Alzheimer's disease and Parkinson's disease (PD). TBI causes serious motor and cognitive impairments, as seen in PD that arise during the period of the initial insult. However, this has been understudied relative to TBI induced neuroinflammation, motor and cognitive decline that progress towards PD. Neuronal ubiquitin-C-terminal hydrolase- L1 (UCHL1) is a thiol protease that breaks down ubiquitinated proteins and its level represents the severity of TBI. Previously, we demonstrated the molecular action of glia maturation factor (GMF); a proinflammatory protein in mediating neuroinflammation and neuronal loss. Here, we show that the weight drop method induced TBI neuropathology using behavioral tests, western blotting, and immunofluorescence techniques on sections from wild type (WT) and GMF-deficient (GMF-KO) mice. Results reveal a significant improvement in substantia nigral tyrosine hydroxylase and dopamine transporter expression with motor behavioral performance in GMF-KO mice following TBI. In addition, a significant reduction in neuroinflammation was manifested, as shown by activation of nuclear factor-kB, reduced levels of inducible nitric oxide synthase, and cyclooxygenase- 2 expressions. Likewise, neurotrophins including brain-derived neurotrophic factor and glial-derived neurotrophic factor were significantly improved in GMF-KO mice than WT 72 h post-TBI. Consistently, we found that TBI enhances GFAP and UCHL-1 expression and reduces the number of dopaminergic TH-positive neurons in WT compared to GMF-KO mice 72 h post-TBI. Interestingly, we observed a reduction of THpositive tanycytes in the median eminence of WT than GMF-KO mice. Overall, we found that absence of GMF significantly reversed these neuropathological events and improved behavioral outcome. This study provides evidence that PD-associated pathology progression can be initiated upon induction of TBI.

The Amphetamine Induced Rotation Test: A Re-Assessment of Its Use as a Tool to Monitor Motor Impairment and Functional Recovery in Rodent Models of Parkinson's Disease

Rats and mice with unilateral damage to the nigrostriatal dopamine system—induced by neurotoxins, such as 6-hydroxydopamine, overexpression of α-synuclein, or injections of toxic synuclein protofibrils—are widely used as experimental models to mimic the loss of dopamine neurons seen in Parkinson’s disease. The amphetamine rotation test is commonly used to monitor the extent of motor impairment induced by the lesion, and this test has also become the standard tool to demonstrate transplant-induced functional recovery or the efficacy of neuroprotective interventions aimed to preserve or restore DA neuron function. Although the amphetamine-induced rotation test is highly useful for this purpose it has some important pitfalls and the interpretation of the data may not always be straightforward. Unless the test is applied properly and the data are displayed and interpreted appropriately the conclusions may be misleading or simply totally wrong. The purpose of this review is to draw attention to the potential problems and pitfalls involved in the use of drug-induced rotation tests, and to provide recommendations and advice on how to avoid them.

Motor learning and COMT Val158met polymorphism: Analyses of oculomotor behavior and corticocortical communication

Differences in motor learning can be partially explained by differences in genotype. The catechol-O-methyltransferase (COMT) Val158Met polymorphism regulates the dopamine (DA) availability in the prefrontal cortex modulating motor learning and performance. Given the differences in tonic and phasic DA transmission, this study aimed to investigate whether the greater cognitive flexibility associated with the Val allele would favor the learning of movement parametrization, while the greater cognitive stability associated with the Met allele favors the acquisition of the movement pattern. Furthermore, we investigated if the genotypic characteristics impact visual scanning of information related to parametrization and to the movement pattern, and the level of cortical connectivity associated with motor planning and control. Performance and learning of a sequential motor task were compared among three genotypes (Val/Val, Val/Met, and Met/Met), as well as their oculomotor behavior and level of cortical coherence. The findings show that the cognitive flexibility promoted by the Val allele is associated with a better parametrization. The search for information through visual scanning was specific to each genotype. Also, a greater cortical connectivity associated with the Val allele was found. The combined study of behavioral, electrophysiological and molecular levels of analysis showed that the cognitive stability and flexibility associated with the COMT alleles, influence specific aspects of motor learning.

Synaptic zinc contributes to motor and cognitive deficits in 6-hydroxydopamine mouse models of Parkinson's disease

Hyperactivity of glutamatergic corticostrial pathways is recognized as a key pathophysiological mechanism contributing to development of PD symptoms and dopaminergic neurotoxicity. Subset of corticostriatal projection neurons uses Zn²⁺ as a co-transmitter alongside glutamate, but the role of synaptically released Zn²⁺ in PD remains unexplored. We used genetically modified mice and pharmacological tools in combination with 6-hydroxydopamine (6-OHDA) lesion models of PD to investigate the contribution of synaptic zinc to disease associated behavioral deficits and neurodegeneration. Vesicular zinc transporter-3 (ZnT3) knockout mice lacking releasable Zn²⁺ were more resistant to locomotor deficit and memory impairment of nigrostriatal dopamine (DA) denervation compared to wildtype littermates. The loss of striatal dopaminergic fibers was comparable between genotypes, indicating that synaptically released Zn²⁺ contributes to behavioral deficits but not neurotoxic effects of 6-OHDA. To gain further insight into the mechanisms of Zn²⁺ actions, we used the extracellular Zn²⁺ chelator CaEDTA and knock-in mice lacking the high affinity Zn²⁺ inhibition of GluN2A-containing NMDA receptors (GluN2A-NMDARs). Acute chelation of extracellular Zn²⁺ in the striatum restored locomotor deficit of 6-OHDA lesion, confirming that synaptic Zn²⁺ suppresses locomotor behavior. Disruption of the Zn²⁺-GluN2A interaction had, on the other hand, no impact on locomotor deficit or neurotoxic effect of 6-OHDA. Collectively, these findings provide clear evidence for the implication of striatal synaptic Zn²⁺ in the pathophysiology of PD. They unveil that synaptic Zn²⁺ plays predominantly a detrimental role by promoting motor and cognitive deficits caused by nigrostriatal DA denervation, pointing towards new therapeutic interventions.

Long-term effects of the glucocorticoid receptor modulator CORT113176 in murine motoneuron degeneration

The Wobbler mouse spinal cord shows vacuolated motoneurons, glial reaction, inflammation and abnormal glutamatergic parameters. Wobblers also show deficits of motor performance. These conditions resemble amyotrophic lateral sclerosis (ALS). Wobbler mice also show high levels of corticosterone in blood, adrenals and brain plus adrenal hypertrophy, suggesting that chronically elevated glucocorticoids prime spinal cord neuroinflammation. Therefore, we analyzed if treatment of Wobbler mice with the glucocorticoid receptor (GR) antagonist CORT113176 mitigated the mentioned abnormalities. 30 mg/kg CORT113176 given daily for 3 weeks reduced motoneuron vacuolation, decreased astro and microgliosis, lowered the inflammatory mediators high mobility group box 1 protein (HMGB1), toll-like receptor 4, myeloid differentiation primary response 88 (MyD88), p50 subunit of nuclear factor kappa B (NFκB), tumor necrosis factor (TNF) receptor, and interleukin 18 (IL18) compared to untreated Wobblers. CORT113176 increased the survival signal pAKT (serine-threonine kinase) and decreased the death signal phosphorylated Junk-N-terminal kinase (pJNK), symptomatic of antiapoptosis. There was a moderate positive effect on glutamine synthase and astrocyte glutamate transporters, suggesting decreased glutamate excitotoxicity. In this pre-clinical study, Wobblers receiving CORT113176 showed enhanced resistance to fatigue in the rota rod test and lower forelimb atrophy at weeks 2-3. Therefore, long-term treatment with CORT113176 attenuated degeneration and inflammation, increased motor performance and decreased paw deformity. Antagonism of the GR may be of potential therapeutic value for neurodegenerative diseases.

Reflex arc recovery after spinal cord dorsal root repair with platelet rich plasma (PRP)

Spinal dorsal roots can be affected by a wide range of lesions, leading to a significant loss of proprioceptive information transmission and greatly affecting motor behavior. In this context, the reimplantation of lesioned roots with platelet-rich plasma (PRP) may allow nerve regeneration. Therefore, the present study evaluated sensorimotor improvement following dorsal root rhizotomy and repair with PRP. For this purpose, female Lewis rats were subjected to unilateral rhizotomy (RZ) of the L4-L6 dorsal roots and divided into the following groups: (1) the unlesioned control group; (2) the group that underwent rhizotomy (RZ) without repair; and (3) the group that underwent RZ followed by root repair with PRP. PRP was obtained from human blood and characterized regarding platelet concentration, integrity, and viability. Reflex arc recovery was evaluated weekly for eight weeks by the electronic von Frey method. The spinal cords were processed 1 week postlesion to evaluate the in vivo gene expression of TNFα, TGF-β, BDNF, GDNF, VEGF, NGF, IL-4, IL-6, IL-13 by qRT-PCR and eight weeks postlesion to evaluate changes in the glial response (GFAP and Iba-1) and excitatory synaptic circuits (VGLUT1) by immunofluorescence. The results indicated that PRP therapy partially restores the paw withdrawal reflex over time, indicating the reentry of primary afferents from the dorsal root ganglia into the spinal cord without exacerbating glial reactivity. Additionally, the analysis of mRNA levels showed that PRP therapy has immunomodulatory properties. Overall, the present data suggest that the repair of dorsal roots with PRP may be considered a promising approach to improve sensorimotor recovery following dorsal rhizotomy.

Gait Ignition Failure in JNPL3 Human Tau-mutant Mice

Cognitive impairments and motor dysfunction are commonly observed behavioral phenotypes in genetic animal models of neurodegenerative diseases. JNPL3 transgenic mice expressing human P301L-mutant tau display motor disturbances with age- and gene dose-dependent development of neurofibrillary tangles, suggesting that tau pathology causes neurodegeneration associated with motor behavioral abnormalities. Although gait ignition failure (GIF), a syndrome marked by difficulty in initiating locomotion, has been described in patients with certain forms of tauopathies, transgenic mouse models mirroring human GIF syndrome have yet to be reported. Using the open field and balance beam tests, here we discovered that JNPL3 homozygous mice exhibit a marked delay of movement initiation. The elevated plus maze excluded the possibility that hesitation to start in JNPL3 mice was caused by enhanced levels of anxiety. Considering the normal gait ignition in rTg4510 mice expressing the same mutant tau in the forebrain, GIF in JNPL3 mice seems to arise from abnormal tau deposition in the hindbrain areas involved in locomotor initiation. Accordingly, immunohistochemistry revealed highly phosphorylated paired helical filament tau in JNPL3 brainstem areas associated with gait initiation. Together, these findings demonstrate a novel behavioral phenotype of impaired gait initiation in JNPL3 mice and underscore the value of this mouse line as a tool to study the neural mechanisms and potential treatments for human GIF syndrome.

Characterization of Motor and Non-Motor Behavioral Alterations in the Dj-1 (PARK7) Knockout Rat

Parkinson's disease is a neurodegenerative disorder that encompasses a constellation of motor and non-motor symptoms. The etiology of the disease is still poorly understood because of complex interactions between environmental and genetic risk factors. Using animal models to assess these risk factors may lead to a better understanding of disease manifestation. In this study, we assessed the Dj-1 knockout (KO) genetic rat model in a battery of motor and non-motor behaviors. We tested the Dj-1 KO rat, as well as age-matched wild-type (WT) control rats, in several sensorimotor tests at 2, 4, 7, and 13 months of age. The Dj-1-deficient rats were found to rear and groom less, and to have a shorter stride length than their WT counterparts, but to take more forelimb and hindlimb steps. In non-motor behavioral tasks, performed at several different ages, we evaluated the following: olfactory function, anxiety-like behavior, short-term memory, anhedonia, and stress coping behavior. Non-motor testing was conducted as early as 4.5 months and as late as 17 months of age. We found that Dj-1 KO animals displayed deficits in short-term spatial memory as early as 4.5 months of age during place preference testing, as well as impaired coping strategies in the forced swim test, which are consistent with a parkinsonian-like phenotype. In some instances, effects of chronic stress were evaluated in the Dj-1-deficient rats, as an initial test of an environmental challenge combined with a genetic disposition for PD. Although some of the results were mixed with differential effects across several of the behaviors, the combination of the changes we observed indicates that the Dj-1 KO rat may be a promising model for the assessment of the prodromal stage of Parkinson's disease, but further evaluation is necessary.

The relationship between task difficulty and motor performance complexity

Difficult tasks are commonly equated with complex tasks across many behaviors. Motor task difficulty is traditionally defined via Fitts' law, using evaluation criteria based on spatial movement constraints. Complexity of data is typically evaluated using non-linear computational approaches. In this project, we investigate the potential to evaluate task difficulty via behavioral (motor performance) complexity in a Fitts-type task. Use of non-linear approaches allows for inclusion of many features of motor actions that are not currently included in the Fitts-type paradigm. Our results indicate that tasks defined as more difficult (using Fitts movement IDs) are not associated with complex motor behaviors; rather, an inverse relationship exists between these two concepts. Use of non-linear techniques allowed for the detection of behavioral differences in motor performance over the entire action trajectory in the presence of action errors and among neutrally co-constrained effectors not detected using traditional Fitts'-type analyses utilizing movement time measures. Our findings indicate that task difficulty may potentially be inferred using non-linear measures, particularly in ecological situations that do not obey the Fitts-type testing paradigm. While we are optimistic regarding these initial findings, further work is needed to assess the full potential of the approach.

Study of transcranial therapy 904 nm in experimental model of stroke

Cerebrovascular accidents (CVAs), commonly known as strokes, can damage the brain through vascular injuries caused by either blood vessel blockages (ischemic stroke) or ruptures (hemorrhagic stroke) which disrupt regular brain blood supply and can cause severe damage to the individual. The objective of the present study was to evaluate the effects of photobiomodulation with a light-emitting diode (LED) device (904 nm, 110 mW, 7 J/cm²) on neurogenesis, muscle resistance, and motor behavior in animals submitted to an experimental model of hemiplegia. The sample consisted of 30 Wistar rats, divided into two groups: control group (GC) and 904-nm LED-treated group (TG). All animals underwent stereotactic surgery for electrode implant and subsequent electrolytic injury to induce an ischemic stroke. TG was subjected to daily LED irradiation (904 nm, 110 mW, 7 J/cm²) for 63 s. Suspension test results indicate an improvement of TG muscle resistance when compared with baseline evaluation (BLT); a reduction in open-field freezing time and the number of fecal bolus pellets suggest diminished anxiety induced by 904-nm LED treatment on treatment days 7 and 21 (TG7 and TG21) compared with the baseline results; and lastly, histological analysis showed important signs of neurogenesis in TG in comparison to CG, especially on treatment days 7 and 21 (TG7 and TG21). In conclusion, the present study suggests that 904-nm LED irradiation may beneficially affect neurogenesis, muscle resistance, and animal motor behavior following ischemic CVA.

Abnormal postural behavior in patients with functional movement disorders during exposure to stress

BACKGROUND

Patients affected by functional (psychogenic) movement disorders (FMD) have abnormal processing of stress responses. However, little is known about the influence of this abnormal stress processing on automatic motor defense behavior, such as freeze response. Our aim was thus to investigate stress-induced postural motor responses in FMD.

METHODS

Nine FMD patients and thirteen healthy controls were engaged in the Trier Social Stress Test, while we measured the movement of their body by means of accelerometers and gyroscopes attached to the thorax. Standard deviation of thorax acceleration, reflecting the variability of movement amplitude (body sway), was compared across groups over time in a 2 × 2 ANOVA design. Higuchi's fractal dimension (HFD), reflecting the complexity of movement pattern over time, was also analyzed. Salivary cortisol and α-amylase samples were collected before and after the experiment, as stress biomarkers. Pearson's correlation coefficients were calculated between these biomarkers and movement parameters.

RESULTS

A significant interaction effect was found, showing that healthy controls reduced their thorax sway over time during exposure to stress (from 0.027 ± 0.010 m/s² to 0.023 ± 0.008 m/s², effect size of Cohen's d = 0.95), whereas patients with FMD did not. This change in body sway in controls over time negatively correlated with salivary cortisol values (ρ = -0.67, p = 0.012). A significant group effect revealed that FMD patients had an overall larger body sway (0.038 ± 0.013 m/s²) compared to controls (0.025 ± 0.009 m/s² - effect size of Cohen's d = 1.29) and a lower HFD (1.602 ± 0.071) than controls (1.710 ± 0.078 - Cohen's d = 1.43).

CONCLUSIONS

Patients with FMD failed to show a reduction of body sway over time, i.e., freeze response observed in the controls, thus suggesting an impairment in the automatic defense behavior. Moreover, our analysis found a lower complexity of movement (HFD) in FMD, which deserves future research in order to verify whether this could represent a characteristic trait of the disorder.

The influence of balance, physical disability, strength, mechanosensitivity and spinal mobility on physical activity at home, work and leisure time in women with fibromyalgia

BACKGROUND

Fibromyalgia syndrome is a chronic disease consisting of widespread pain, fatigue, sleep disturbances, and cognitive impairments, among other symptoms, which affect daily physical activity. However, the influence of functional status on physical activity involved in leisure, household and work activities has not been researched previously. The main objective was to evaluate balance, strength, spinal mobility, mechanosensitivity and function levels as related factors of physical activity in female with fibromyalgia.

METHODS

Thirty-four patients with Fibromyalgia and 22 matched controls were included in a cross-sectional study. Dynamic and static balance, general and daily activities disability, lumbosacral mechanosensitivity, spinal range of motion, lower limb strength, physical activity in leisure, household and work activities were registered. We tested for differences between groups by using independent sample t-tests. The influence of demographics, symptoms and physical outcomes on physical activity was statistically analyzed using bivariate and multivariate regression analyses.

FINDINGS

There was a significant association between leisure-time physical activity scores and age (r = 0.564), spinal flexion (r = 0.512), spinal extension (r = 0.421) and the total range of spinal inclination (r = 0.533). Fifty-eight percent of the variance of leisure-time physical activity was explained by age and range of spinal flexion-extension. Similarly, functional mobility was associated with physical activity at home and work scores (r = 0.459), explaining 21% of its variance.

INTERPRETATION

A higher time spent in leisure, household and work activities was related to higher age, spinal range of motion and lower functional mobility in women with Fibromyalgia. Rehabilitation intervention programs should promote physical activity at home, work and leisure time.

Interplay between hypoactivity, muscle properties and motor command: How to escape the vicious deconditioning circle?

Activity-dependent processes addressing the central nervous system (CNS) and musculoskeletal structures are critical for maintaining motor performance. Chronic reduction in activity, whether due to a sedentary lifestyle or extended bed rest, results in impaired performance in motor tasks and thus decreased quality of life. In the first part of this paper, we give a narrative review of the effects of hypoactivity on the neuromuscular system and behavioral outcomes. Motor impairments arise from a combination of factors including altered muscle properties, impaired afferent input, and plastic changes in neural structure and function throughout the nervous system. There is a reciprocal interplay between the CNS and muscle properties, and these sensorimotor loops are essential for controlling posture and movement. As a result, patients under hypoactivity experience a self-perpetuating cycle, in with sedentarity leading to decreased motor activity and thus a progressive worsening of a situation, and finally deconditioning. Various rehabilitation strategies have been studied to slow down or reverse muscle alteration and altered motor performance. In the second part of the paper, we review representative protocols directed toward the muscle, the sensory input and/or the cerebral cortex. Improving an understanding of the loss of motor function under conditions of disuse (such as extended bed rest) as well as identifying means to slow this decline may lead to therapeutic strategies to preserve quality of life for a range of individuals. The most efficient strategies seem multifactorial, using a combination of approaches targeting different levels of the neuromuscular system.