Traumatic brain injury, alone or with striatal hemorrhage-like extension, transiently decreases GABA and glutamate levels along motor deficits in the rat striatum: an in vivo study.

The cerebral cortex is connected to the striatum via the axons of the pyramidal glutamatergic neurons, and this pathway is intimately involved in motor function. In the striatum, glutamatergic afferents initiate the activity of GABAergic medium spiny neurons. This study addressed whether traumatic brain injury (TBI) affects GABA and glutamate extracellular levels in the dorsal striatum as an indicator of effects on the cortico-striatal pathway, in rats with motor deficits and recovered animals. Animals were assigned to a sham group, a TBI-alone group, and a TBI + striatal injury group (local injection of a FeCl2 solution to mimic hemorrhagic lesion). In the TBI-alone and TBI + striatal injury groups, motor deficits were accompanied by decreased extracellular GABA and glutamate levels in the striatum at 3 days post-injury. The TBI + striatal injury group showed higher motor deficits, which lasted 7 days longer, and GABA levels were significantly different compared to the TBI alone group. At 18 days post-injury, in recovered rats from the TBI-alone group GABA and glutamate levels returned to control levels. Alterations in extracellular GABA and glutamate levels indicate damage to the cortico-striatal pathway, underscoring the importance of studying this pathway for treatment and recovery after TBI.

D1 Receptor Functional Asymmetry at Striatonigral Neurons: A Neurochemical and Behavioral Study in Male Wistar Rats.

Lateralization of motor behavior, a common phenomenon in humans and several species, is modulated by the basal ganglia, a site pointed out for the interhemispheric differences related to lateralization. Our study aims to shed light on the potential role of the striatonigral D1 receptor in functional asymmetry in normal conditions through neurochemical and behavioral means. We found that D1 receptor activation and D1/D3 receptor coactivation in striatonigral neurons leads to more cAMP production by adenylyl cyclase in the striatum and GABA release in their terminals in the right hemisphere compared to the left. These differences are linked to a higher receptor sensitivity and potentially a better coupling of Golf proteins. When we assessed motor behavior through intranigral injection of the D1 receptor agonist SKF 38393 in the left or right substantia nigra, we found higher contralateral circling when injected on the right side. Thus, differences in motor activity correlate with neurochemical data, indicating that D1 receptor signaling plays a significant role in motor asymmetry.

Longitudinal Change in Physical Activity in Children 6 to 36 Months of Age.

OBJECTIVE: To describe the developmental pattern for physical activity (PA) in children 6-36 months of age and to identify factors that are longitudinally associated with PA as children transition from infancy to preschool age. STUDY DESIGN: The study employed a prospective longitudinal design with baseline data collected when children were approximately 6 months of age. Mothers and infants (n = 124) were recruited through community and educational settings in South Carolina. Data were collected at 6-month intervals from 6 to 36 months. PA was measured via accelerometry. Mothers completed questionnaires that assessed independent variables, including parent characteristics, the child's sex, race, and ethnicity, birth/delivery type, motor milestones, sleep habits, dietary practices, childcare setting, and home environmental factors. Trained research staff administered anthropometric measures and assessed motor developmental status. Growth curve models described the age-related pattern for PA and evaluated relationships between independent variables and change in PA. RESULTS: PA increased by approximately 45% between 6 and 36 months of age and followed a curvilinear pattern, with most of the increase occurring between 6 and 24 months. The child's exposure to television/electronic media was negatively associated with change in PA, and the presence of older siblings in the home was positively associated with change in PA. CONCLUSIONS: As children develop from infancy to early childhood, their PA increases substantially, with most of the increase occurring by 24 months of age.

Improvement of motor function in mice after implantation of mononuclear stem cells from human umbilical cord and placenta blood after 3 and 6 weeks of experimental spinal cord injury.

STUDY DESIGN: Experimental study utilizing with a standardized model (MASCIS Impactor) of Spinal Cord Injury (SCI) in Balb C mouse model with implantation of mononuclear stem cells derived from the human umbilical cord and placenta blood in the early chronic phase of SCI. OBJECTIVES: The aim of this study was to evaluate the nerve regeneration and motor functional recovery in Balb C mice with surgically induced paraplegia in response to the use of mononuclear stem cells, in early chronic phase (> 2 weeks and < 6 months), because there is yet potential of neuronal and functional recovery as the neuronal scar is not still completely established. METHODS: Forty-eight mice were randomly assigned to 6 groups of 8 animals. Group 1 received the stem cells 3 weeks after the trauma, and Group 2 received them six weeks later. In Group 3, saline solution was injected at the site of the lesion 3 weeks after the trauma, and in Group 4, 6 weeks later. Group 5 underwent only spinal cord injury and Group 6 underwent laminectomy only. The scales used for motor assessment were BMS and MFS for 12 weeks. RESULTS: The intervention groups showed statistically significant motor improvement. In the histopathological analysis, the intervention groups had a lower degree of injury (p < 0.05). Regarding axonal budding, the intervention groups showed increasing in axonal budding in the caudal portion (p < 0.05). CONCLUSIONS: The use of stem cells in mice in the chronic phase after 3 and 6 weeks of SCI brings functional and histopathological benefits to them.

Impact of 5-Lipoxygenase Deficiency on Dopamine-Mediated Behavioral Responses.

The 5-lipoxygenase/leukotriene system has been implicated in both physiological and pathological states within the central nervous system. Understanding how this system interacts with the dopaminergic system could provide valuable insights into dopamine-related pathologies. This study focused on examining both motor and non-motor dopamine-related responses in 5-lipoxygenase/leukotriene-deficient mice. We used pharmacological agents such as amphetamine, apomorphine, and reserpine to challenge the dopaminergic system, evaluating their effects on prepulse inhibition reaction (PPI), general motor activity, and oral involuntary movements. Additionally, we analyzed striatal glial marker expression (GFAP and Iba-1) in reserpine-treated mice. The 5-lipoxygenase/leukotriene-deficient mice exhibited increased spontaneous locomotor activity, including both horizontal and vertical exploration, along with stereotyped behavior compared to wild-type mice. This hyperactivity was reduced by acute apomorphine treatment. Although basal PPI responses were unchanged, 5-lipoxygenase/leukotriene-deficient mice displayed a significant reduction in susceptibility to amphetamine-induced PPI disruption. Conversely, these mice were more vulnerable to reserpine-induced involuntary movements. There were no significant differences in the basal expression of striatal GFAP and Iba-1 positive cells between 5-lipoxygenase/leukotriene-deficient and wild-type mice. However, reserpine treatment significantly increased GFAP immunoreactivity in wild-type mice, an effect not observed in 5-lipoxygenase-deficient mice. Additionally, the percentage of activated microglia was significantly higher in reserpine-treated wild-type mice, an effect absents in 5-lipoxygenase/leukotriene-deficient mice. Our findings suggest that 5-lipoxygenase/leukotriene deficiency leads to a distinctive dopaminergic phenotype, indicating that leukotrienes may influence the modulation of dopamine-mediated responses.

Transitional photoperiod induces a mania-like behavior in male mice.

This study aimed to investigate the behavioral responses and circadian rhythms of mice to both rapid and gradual increases in photoperiod, mimicking the transition from winter to summer, which is associated with a heightened prevalence of hospitalizations for mania and suicidal behavior. Behavioral tests were performed in C57BL/6 male mice exposed to a transitional photoperiod, from short to long durations. To determine if circadian rhythms are affected, we measured spontaneous locomotor activity and body temperature. Mice exhibited heightened exploratory and risk-taking behaviors compared with equatorial and static long (16:8 h of light-dark cycle for several days) groups. These behaviors were prevented by lithium. Spontaneous locomotor activity and body temperature rhythms persisted and were effectively synchronized; however, the relative amplitude of activity and interdaily stability were diminished. Additionally, the animals displayed increased activity during the light phase. Photoperiodic transition modulates behavior and circadian rhythms, mirroring certain features observed in bipolar disorder patients. This study introduces an animal model for investigating mania-like behavior induced by photoperiodic changes, offering potential insights for suicide prevention strategies and the management of mood disorders.

Divergent patterns of locomotor activity in cave isopods (Oniscidea: Styloniscidae) in Neotropics.

In cave environments, stable conditions devoid of light-dark cycles and temperature fluctuations sustain circadian clock mechanisms across various species. However, species adapted to these conditions may exhibit disruption of circadian rhythm in locomotor activity. This study examines potential rhythm loss due to convergent evolution in five semi-aquatic troglobitic isopod species (Crustacea: Styloniscidae), focusing on its impact on locomotor activity. The hypothesis posits that these species display aperiodic locomotor activity patterns. Isopods were subjected to three treatments: constant red light (DD), constant light (LL), and light-dark cycles (LD 12:12), totaling 1656 h. Circadian rhythm analysis employed the Sokolove and Bushell periodogram chi-square test, Hurst coefficient calculation, intermediate stability (IS), and activity differences for each species. Predominantly, all species exhibited an infradian rhythm under DD and LL. There was synchronization of the locomotor rhythm in LD, likely as a result of masking. Three species displayed diurnal activity, while two exhibited nocturnal activity. The Hurst coefficient indicated rhythmic persistence, with LD showing higher variability. LD conditions demonstrated higher IS values, suggesting synchronized rhythms across species. Significant individual variations were observed within species across the three conditions. Contrary to the hypothesis, all species exhibited synchronization under light-dark conditions. Analyzing circadian activity provides insights into organism adaptation to non-cyclical environments, emphasizing the importance of exploring underlying mechanisms.

Repeated ovarian hyperstimulation promotes depression-like behavior in female mice.

Controlled ovarian hyperstimulation (COH) is a common step for treating infertile couples undergoing assisted reproductive technologies and in female fertility preservation cycles. In some cases, undergoing multiple COHs is required for couples to conceive. Behavioral changes such as anxiety and depression can be caused by ovulation-inducing drugs. Sex steroids play a role in locomotor activity, behavioral changes, and nociception, specifically during fluctuations and sudden drops in estrogen levels. This study evaluated the effect of repeated ovarian hyperstimulation (ROH) on weight, locomotor activity, anxiety-like and depression-like behavior, and nociception in female mice. The animals were divided into two groups: control (placebo; Control) and treated (ROH; Treatment). Ovulation was induced once weekly for 10 consecutive weeks. Locomotor activity (open field test), anxiety-like behavior (elevated plus maze, hole board, and marble burying tests), depression-like behavior (splash and forced swim tests), and nociception (hot plate and Von Frey tests) were evaluated before and after ROH. Statistical analysis was conducted using two-way analysis of variance to evaluate the effects of ROH, age of mice, and their interaction. The results suggested that ROH contributed to weight gain, increased locomotor activity, and induced depression-like behavior in female mice. Furthermore, the age of the mouse contributed to weight gain, increased locomotor activity, and induced anxiety-like and depression-like behavior in female mice. ROH could change the behavior of female mice, particularly inducing depression-like behavior. Further studies are required to evaluate various COH protocols, specifically with drugs that prevent fluctuations and drastic drops in estrogen levels, such as aromatase inhibitors.

A versatile recording device for the analysis of continuous daily external activity in colonies of highly eusocial bees.

As pollinators, bees are key to maintaining the biodiversity of angiosperm plants, and for agriculture they provide a billion-dollar ecosystem service. But they also compete for resources (primarily nectar and pollen), especially the highly social bees that live in perennial colonies. So, how do they organize their daily temporal activities? Here, we present a versatile, low-cost device for the continuous, automatic recording and data analysis of the locomotor activity in the colony-entrance tube of highly eusocial bees. Consisting of an in-house built block containing an infrared detector, the passage of bees in the colony entrance tunnel is registered and automatically recorded in an Arduino environment, together with concomitant recordings of temperature and relative humidity. With a focus on the highly diverse Neotropical stingless bees (Meliponini), we obtained 10-day consecutive recordings for two colonies each of the species Melipona quadrifasciata and Frieseomelitta varia, and also for the honey bee. The Lomb-Scargle periodogram analysis identified a predominant circadian rhythmicity for all three species, but also indications of ultradian rhythms. For M. quadrifasciata, which is comparable in size to the honey bee, we found evidence for a possibly anticipatory activity already before sunrise. As all three species also presented activity at night in the colony entrance tube, this also raises questions about sleep organization in social insects. The cost and versatility of the device and the open-source options for data analysis make this an attractive system for conducting studies on circadian rhythms in social bees under natural conditions, complementing studies on flower visits by these important pollinators.

Reestablishment of ad libitum feeding following partial food deprivation: Impact on locomotor activity, visceral fat, food intake, and circadian glycemic curve.

Food deprivation has been associated with the development of metabolic pathologies. Few studies have explored the repercussions of a partial food deprivation following the reestablishment of an ad libitum diet. This study investigates the impact of a partial food deprivation (an 8-hour food intake restriction coupled with a 4-hour feeding window during the active phase) and the subsequent return to ad libitum feeding on the glycemic curve, food intake, and locomotor behavior. Wistar rats aged 45 days were subjected to 6 weeks of a partial food deprivation followed by 6 weeks of ad libitum feeding. Body weight, visceral fat, food intake, circadian glycemia, oral glucose tolerance, and locomotor activity were evaluated. It was found that the partial food deprivation resulted in the reduction of both the body weight and food intake; however, it increased visceral fat by 60%. Circadian glycemic values were altered at all intervals during the light phase, and glucose sensitivity improved at 60 minutes in the oral glucose tolerance test (OGTT). In the food-deprived group, the locomotor activity rhythm was reduced, with an observed delay in the peak of activity, reduction in total activity, and a decrease in the rhythmicity percentage. After the reestablishment of the ad libitum feeding, there was recovery of body weight, no difference in visceral fat, normalization of the food intake pattern, circadian glycemia, and oral glucose tolerance. Additionally, the return to ad libitum feeding restored locomotor activity, although the duration required for its complete recovery warrants further investigation. In conclusion, partial food deprivation induces physio-metabolic changes in rats, most of which are reversed after reestablishing ad libitum feeding.

Changes in energy expenditure and physical activity over 15 years of environmental changes: The Maycoba project.

OBJECTIVE: This work aimed to parse out the role of changing environments on body composition, total energy expenditure, and physical activity in the Mexican Pima, a population experiencing rapid industrialization. METHODS: Using doubly labeled water, we compared energy expenditure and physical activity in a longitudinal cohort of Mexican Pima (n = 26; female: 12) in 1995 and 2010. Body mass and composition were assessed by bioimpedance analysis. To determine the effects of environmental factors on body weight independent of age, we compared the 1995 longitudinal cohort with an age- and sex-matched cross-sectional cohort (n = 26) in 2010. RESULTS: Body mass, fat mass, and fat-free mass all significantly increased between 1995 and 2010. Despite a 13% average increase in body weight, weight-adjusted total daily energy expenditure decreased significantly. Measured physical activity levels also decreased between 1995 and 2010, after we adjusted for weight. CONCLUSIONS: Our results suggest that the recent industrialization of the Maycoba region in Sonora, Mexico, has contributed to a decrease in physical activity, in turn contributing to weight gain and metabolic disease among the Mexican Pima.

Spatio-temporal modulation of cortical activity during motor deadaptation depends on the feedback of task-related error.

Motor adaptations are responsible for recalibrating actions and facilitating the achievement of goals in a constantly changing environment. Once consolidated, the decay of motor adaptation is a process affected by available sensory information during deadaptation. However, the cortical response to task error feedback during the deadaptation phase has received little attention. Here, we explored changes in brain cortical responses due to feedback of task-related error during deadaptation. Twelve healthy volunteers were recruited for the study. Right hand movement and EEG were recorded during repetitive trials of a hand reaching movement. A visuomotor rotation of 30° was introduced to induce motor adaptation. Volunteers participated in two experimental sessions organized in baseline, adaptation, and deadaptation blocks. In the deadaptation block, the visuomotor rotation was removed, and visual feedback was only provided in one session. Performance was quantified using angle end-point error, averaged speed, and movement onset time. A non-parametric spatiotemporal cluster-level permutation test was used to analyze the EEG recordings. During deadaptation, participants experienced a greater error reduction when feedback of the cursor was provided. The EEG responses showed larger activity in the left centro-frontal parietal areas during the deadaptation block when participants received feedback, as opposed to when they did not receive feedback. Centrally distributed clusters were found for the adaptation and deadaptation blocks in the absence of visual feedback. The results suggest that visual feedback of the task-related error activates cortical areas related to performance monitoring, depending on the accessible sensory information.

Glutathione effect on functional and histological recovery after spinal cord injury in rats.

OBJECTIVE: The aim of this study was to evaluate the GSH effect on functional and histological recovery after experimental spinal cord injury in rats. METHODS: Forty Wistar rats were subjected to spinal cord injury through the Multicenter Animal Spinal Cord Injury Study (MASCIS) Impactor system. The rats were sorted and divided into four groups, as follows: Group 1 ‒ Laminectomy and spinal cord injury; Group 2 ‒ Laminectomy, spinal cord injury and Saline Solution (SS) 0.9%; Group 3 ‒ Laminectomy, spinal cord injury, and GSH; and Group 4 ‒ lLaminectomy without spinal cord injury. GSH and SS were administered intraperitoneally. Groups 1 and 4 received no intervention. RESULTS: The rats were evaluated for locomotor function recovery at seven different times by the Basso, Beattie, and Bresnahan (BBB) scale on days 2, 7, 14, 21, 28, 35, and 42 after the spinal cord injury. On day 42, the rats were sacrificed to analyze the histological findings of the injured spinal cord. In the group submitted to GSH, our experimental study revealed better functional scores on the BBB scale, horizontal ladder scale, and cranial and caudal axon count. The differences found were statistically significant in BBB scores and axonal count analysis. CONCLUSION: This study demonstrated that using glutathione in experimental spinal trauma can lead to better functional recovery and improved axonal regeneration rate in Wistar rats submitted to experimental spinal cord injury.

Dietary restriction modulates ultradian rhythms and autocorrelation properties in mice behavior.

Animal behavior emerges from integration of many processes with different spatial and temporal scales. Dynamical behavioral patterns, including daily and ultradian rhythms and the dynamical microstructure of behavior (i.e., autocorrelations properties), can be differentially affected by external cues. Identifying these patterns is important for understanding how organisms adapt to their environment, yet unbiased methods to quantify dynamical changes over multiple temporal scales are lacking. Herein, we combine a wavelet approach with Detrended Fluctuation Analysis to identify behavioral patterns and evaluate changes over 42-days in mice subjected to different dietary restriction paradigms. We show that feeding restriction alters dynamical patterns: not only are daily rhythms modulated but also the presence, phase and/or strength of ~12h-rhythms, as well as the nature of autocorrelation properties of feed-intake and wheel running behaviors. These results highlight the underlying complexity of behavioral architecture and offer insights into the multi-scale impact of feeding habits on physiology.

Resting-state EEG as Biomarker of Maladaptive Motor Function and Depressive Profile in Stroke Patients.

Objective: Investigate the relationship between resting-state EEG-measured brain oscillations and clinical and demographic measures in Stroke patients. Methods: We performed a cross-sectional analysis of a cohort study (DEFINE cohort), Stroke arm, with 85 patients, considering demographic, clinical, and stroke characteristics. Resting-state EEG relative power from delta, theta, alpha, and beta oscillations were measured from the central region. Multivariate regression models were used for both affected and non-affected hemispheres. Results: Motor function was negatively associated with Delta and Theta oscillations, while positively associated with Alpha oscillations (both hemispheres). Similarly, cognition levels measured were negatively associated with Delta activity. Depression levels were negatively associated with Alpha activity specifically in the affected hemisphere, while positively associated with Beta activity in both hemispheres. Regarding pain measures, no significant association was observed, while CPM measure showed a positive association with Alpha activity in the non-affected hemisphere. Finally, we found that theta/alpha ratio was negatively associated with motor function and CPM scores. Conclusion: The results lead us to propose a framework for brain oscillations in stroke, whereas Delta and Beta would represent disrupted mal-adaptive brain plasticity and Theta and Alpha would represent compensatory and functional brain oscillations for motor and sensory deficits in stroke, respectively.

Sleep deprivation induces late deleterious effects in a pharmacological model of Parkinsonism.

Parkinson's disease is a degenerative, chronic and progressive disease, characterized by motor dysfunctions. Patients also exhibit non-motor symptoms, such as affective and sleep disorders. Sleep disorders can potentiate clinical and neuropathological features and lead to worse prognosis. The goal of this study was to evaluate the effects of sleep deprivation (SD) in mice submitted to a progressive pharmacological model of Parkinsonism (chronic administration with a low dose of reserpine). Male Swiss mice received 20 injections of reserpine (0.1 mg/kg) or vehicle, on alternate days. SD was applied before or during reserpine treatment and was performed by gentle handling for 6 h per day for 10 consecutive days. Animals were submitted to motor and non-motor behavioral assessments and neurochemical evaluations. Locomotion was increased by SD and decreased by reserpine treatment. SD during treatment delayed the onset of catalepsy, but SD prior to treatment potentiated reserpine-induced catalepsy. Thus, although SD induced an apparent beneficial effect on motor parameters, a delayed deleterious effect on alterations induced by reserpine was found. In the object recognition test, both SD and reserpine treatment produced cognitive deficits. In addition, the association between SD and reserpine induced anhedonic-like behavior. Finally, an increase in oxidative stress was found in hippocampus of mice subjected to SD, and tyrosine hydroxylase immunoreactivity was reduced in substantia nigra of reserpine-treated animals. Results point to a possible late effect of SD, aggravating the deficits in mice submitted to the reserpine progressive model of PD.

Improving motor imagery through a mirror box for BCI users.

The aim of this study was to evaluate mirror visual feedback (MVF) as a training tool for brain-computer interface (BCI) users. This is because approximately 20-30% of subjects require more training to operate a BCI system using motor imagery. Electroencephalograms (EEGs) were recorded from 18 healthy subjects, using event-related desynchronization (ERD) to observe the responses during the movement or movement intention of the hand for the conditions of control, imagination, and the MVF with the mirror box. We constituted two groups: group 1: control, imagination, and MVF; group 2: control, MVF, and imagination. There were significant differences in imagination conditions between groups using MVF before or after imagination (right-hand, P = 0.0403; left-hand, P = 0.00939). The illusion of movement through MVF is not possible in all subjects, but even in those cases, we found an increase in imagination when the subject used the MVF previously. The increase in the r2s of imagination in the right and left hands suggests cross-learning. The increase in motor imagery recorded with EEG after MVF suggests that the mirror box made it easier to imagine movements. Our results provide evidence that the MVF could be used as a training tool to improve motor imagery.NEW & NOTEWORTHY The increase in motor imagery recorded with EEG after MVF (mirror visual feedback) suggests that the mirror box made it easier to imagine movements. Our results demonstrate that MVF could be used as a training tool to improve motor imagery.

Grade-4/5 motor activity log-Brazil for post-stroke individuals with a severely impaired upper limb: a validity, reliability and measurement error study.

PURPOSE: This study examined the clinimetrics of the Brazilian-Portuguese translation of the Grade-4/5 Motor Activity Log (MAL 4/5), which assesses everyday use of the more affected upper-limb (UL) in stroke survivors with moderate/severe or severe motor impairment. MATERIALS AND METHODS: The translated MAL 4/5 was administered to 47 stroke survivors with moderate/severe or severe UL motor impairment. Accelerometers were worn on participants' wrists for five days on average prior to the first assessment. Test-retest and inter-rater reliabilities were assessed using the intraclass correlation coefficient (ICC), internal consistency using Cronbach's α, and construct validity was tested with correlations with the accelerometry. The measurement error (SEM) and the minimal detectable change (MDC) were calculated. RESULTS: MAL4/5-Brazil's test-retest reliability (AOU: ICC = 0.84; QOU: ICC = 0.90), inter-rater reliability (AOU: ICC = 0.83; QOU: ICC = 0.91), internal consistency (Cronbach's α = 0.91 and 0.95 for AOU and QOU scales, respectively), the SEM and MDC were 0.3 and 0.8 points for the AOU subscale and 0.2 and 0.5 points for the QOU subscale, respectively. The construct validity (AOU scale: r = 0.67; QOU scale: r = 0.76) was high. CONCLUSION: Grade-4/5 Motor Activity Log-Brazil is a reliable and valid instrument for assessing the more-affected UL use of stroke patients with moderate/severe or severe UL motor impairments.

Reliability and concurrent validity of the Grade-4/5 MAL-Brazil were established in adults with hemiparesis moderate/severe or severe upper extremity post Stroke.The minimum detectable change for the Grade-4/5 MAL-Brazil was 0.8 points for the Amount of Use scale and 0.5 points for the Quality of Use scale.Data from the accelerometry supports the construct validity of this instrument.The assessment can now be used clinically and for research in adults with impairment upper extremity moderate/severe or severe post Stroke.