Feeding anatomy,filter-feeding rate,and diet of whale sharks Rhincodon typus during surface ram filter feeding off the Yucatan Peninsula,Mexico

The feeding anatomy, behavior and diet of the whale shark Rhincodon typus were studied off Cabo Catoche, Yucatan Peninsula, Mexico. The filtering apparatus is composed of 20 unique filtering pads that completely occlude the pharyngeal cavity. A reticulated mesh lies on the proximal surface of the pads, with openings averaging 1.2 mm in diameter. Superficial to this, a series of primary and secondary cartilaginous vanes support the pads and direct the water across the primary gill filaments. During surface ram filter feeding, sharks swam at an average velocity of 1.1 m/s with 85% of the open mouth below the water's surface. Sharks on average spent approximately 7.5 h/day feeding at the surface on dense plankton dominated by sergestids, calanoid copepods, chaetognaths and fish larvae. Based on calculated flow speed and underwater mouth area, it was estimated that a whale shark of 443 cm total length (TL) filters 326 m³/h, and a 622 cm TL shark 614 m³/h. With an average plankton biomass of 4.5 g/m³ at the feeding site, the two sizes of sharks on average would ingest 1467 and 2763 g of plankton per hour, and their daily ration would be approximately 14,931 and 28,121 kJ, respectively. These values are consistent with independently derived feeding rations of captive, growing whale sharks in an aquarium. A feeding mechanism utilizing cross-flow filtration of plankton is described, allowing the sharks to ingest plankton that is smaller than the mesh while reducing clogging of the filtering apparatus.     

Digestive capacities allow the Mexican long-nosed bat (Leptonycteris nivalis) to live in cold environments

Digestive capabilities of nectar-feeding vertebrates to assimilate sugars affect their ability to acquire and store energy and could determine the minimal temperatures at which these animals can survive. Here, we described the sugar digestive capability of Leptonycteris nivalis and related it with its capacity to live in cold environments. We measured the enzymatic activity, food intake rate and changes in body mass of bats feeding at four different sucrose concentrations (from 5 to 35% wt./vol.). Additionally, we used a mathematical model to predict food intake and compared it with the food intake of bats. L. nivalis was able to obtain ~ 111.3 kJ of energy regardless of the sugar concentration of their food. Also, bats gained ~ 2.57 g of mass during the experimental trials and this gain was independent of sugar concentration. The affinity (1 / K_m) of sucrase (EC 3.2.1.48) was one order of magnitude higher relative to that reported for its sister species Leptonycteris yerbabuenae (0.250 and 0.0189 mmol^? 1 L, respectively), allowing this species to have a higher energy intake rate. We propose that the high ability to acquire energy conferred L. nivalis the faculty to invade cold environments, avoiding in this way the ecological competition with its sympatric species L. yerbabuenae.     

Effects of plyometric and pneumatic explosive strength training on neuromuscular function and dynamic balance control in 60–70 year old males

The present study compared neuromuscular adaptations to 12 weeks of plyometric (PLY) or pneumatic (PNE) power training and their effects on dynamic balance control. Twenty-two older adults aged 60–70 (PLY n = 9, PNE n = 11) participated in the study. Measurements were conducted at Pre, 4, 8 and 12 weeks. Dynamic balance was assessed as anterior–posterior center of pressure (COP) displacement in response to sudden perturbations. Explosive isometric knee extension and plantar flexion maximal voluntary contractions (MVCs) were performed. Maximal drop jump performance from optimal dropping height was measured in a sledge ergometer. Increases in knee extensor and ankle plantar flexor torque and muscle activity were higher and occurred sooner in PNE, whereas in drop jumping, PLY showed a clearer increase in optimal drop height (24%, p < 0.01) after 8 weeks of training and soleus muscle activity after 12 weeks of training. In spite of these training mode specific adaptations, both groups showed similar improvements in dynamic balance control after 4 weeks of training (PLY 38%, p < 0.001; PNE 31%, p < 0.001) and no change thereafter. These results show that although power and plyometric training may involve different neural adaptation mechanisms, both training modes can produce similar improvements in dynamic balance control in older individuals. As COP displacement was negatively correlated with rapid knee extension torque in both groups (PLY r = −0.775, p < 0.05; PNE r = −0.734, p < 0.05) after training, the results also highlight the importance of targeting rapid force production when training older adults to improve dynamic balance.     

Place learning prior to and after telencephalon ablation in bamboo and coral cat sharks (Chiloscyllium griseum and Atelomycterus marmoratus)

This study assessed complex spatial learning and memory in two species of shark, the grey bamboo shark (Chiloscyllium griseum) and the coral cat shark (Atelomycterus marmoratus). It was hypothesized that sharks can learn and apply an allocentric orientation strategy. Eight out of ten sharks successfully completed the initial training phase (by locating a fixed goal position in a diamond maze from two possible start points) within 14.9 ± 7.6 sessions and proceeded to seven sets of transfer tests, in which sharks had to perform under altered environmental conditions. Transfer tests revealed that sharks had oriented and solved the tasks visually, using all of the provided environmental cues. Unintentional cueing did not occur. Results correspond to earlier studies on spatial memory and cognitive mapping in other vertebrates. Future experiments should investigate whether sharks possess a cognitive spatial mapping system as has already been found in several teleosts and stingrays. Following the completion of transfer tests, sharks were subjected to ablation of most of the pallium, which compromised their previously acquired place learning abilities. These results indicate that the telencephalon plays a crucial role in the processing of information on place learning and allocentric orientation strategies.     

Effects of lead exposure on the expression of amyloid β and phosphorylated tau proteins in the C57BL/6 mouse hippocampus at different life stages

The objective of this study was to investigate the effects of lead exposure on spatial learning and memory capacity and the expression of amyloid β and phosphorylated tau proteins in the mouse hippocampus. A total of 24 adult C57BL/6 mice (12 of each sex) were mated at a 1:1 ratio. After delivery, the litters were normalised to 6 pups per litter. During the lactation period, the pups were randomly separated into four groups: control, early exposure, late exposure, or long-term exposure. These groups were not exposed to lead, exposed to lead from birth to week 24, exposed to lead from week 24 to week 48, or exposed to lead from birth to 48 weeks of age, respectively. Lead exposure was induced by providing Pb-contaminated drinking water at a concentration of 0.1%. All of the pups were fed until 72 weeks of age, at which time their spatial learning and memory capacity was evaluated via the Morris water maze test. Then, the lead levels in their blood and hippocampus were measured via graphite furnace atomic absorption spectrometry. The protein expression of amyloid β and phosphorylated tau in the hippocampus was detected via Western blot. The results revealed that the hippocampal and blood lead levels were significantly higher in all of the groups exposed to lead than the control group (P < 0.05). The spatial learning and memory performances of the lead-exposed groups were much poorer than those of the control group (P < 0.05). The expression levels of amyloid β and phosphorylated tau proteins were increased in the lead-exposed groups compared to the control group (P < 0.05). The enhanced expressions of amyloid β and phosphorylated tau proteins might contribute to the impairment in spatial learning and memory in the lead-exposed mice.     

The effects of post-stroke upper-limb training with an electromyography (EMG)-driven hand robot

Loss of hand function and finger dexterity are main disabilities in the upper limb after stroke. An electromyography (EMG)-driven hand robot had been developed for post-stroke rehabilitation training. The effectiveness of the hand robot assisted whole upper limb training was investigated on persons with chronic stroke (n = 10) in this work. All subjects attended a 20-session training (3–5 times/week) by using the hand robot to practice object grasp/release and arm transportation tasks. Significant motor improvements were observed in the Fugl-Meyer hand/wrist and shoulder/elbow scores (p < 0.05), and also in the Action Research Arm Test and Wolf Motor Function Test (p < 0.05). Significant reduction in spasticity of the fingers as was measured by the Modified Ashworth Score (p < 0.05). The training improved the muscle co-ordination between the antagonist muscle pair (flexor digitorum (FD) and extensor digitorum (ED)), associated with a significant reduction in the ED EMG level (p < 0.05) and a significant decrease of ED and FD co-contraction during the training (p < 0.05); the excessive muscle activities in the biceps brachii were also reduced significantly after the training (p < 0.05).     

Construction and characterization of a cDNA library from shark regenerated hepatic tissue

Sharks are a type of fish with a full cartilaginous skeleton and have big livers. To better understand liver regeneration in sharks and screening for the important genes participated in disease-defense, in this study, a cDNA library of regenerated liver tissues of shark, Chiloscyllium plagiosum, was constructed. A total of 2103 expressed sequence tags (ESTs), which represents 997 unique genes, were sequenced. Among these genes, 434 (43.53%) of them showed significant similarity (E-values < 10^?5) to the sequences in NCBI Nt database, 685 (68.71%) of these unique genes showed significant similarity (E-values < 10^?5) to the sequences in NCBI Nr database, and 662 (66.40%) of these unique genes showed significant similarity (E-values < 10^?5) to the Swiss-Prot database. Preliminary analysis of unique genes according to COG database showed that unigenes were further grouped into 21 functional categories including inorganic ion transport and metabolism, energy production and conversion, posttranslational modification, protein turnover and chaperones, general function prediction only, translation, and ribosomal structure and biogenesis. Several possible candidate genes involved in liver regeneration were selected to analyze their expression with relative quantification real-time PCR. This study may contribute to our better understanding of the molecular mechanism of regeneration in shark liver. Furthermore, the EST cataloguing and profiling of shark will be also benefited to the functional genomic research in this marine species.     

The effects of different exercise training modalities on plasma proenkephalin Peptide F in women

Due to the important interactions of proenkephalin fragments (e.g., proenkephalin [107–140] Peptide F) to enhance activation of immune cells and potentially combat pain associated with exercise-induced muscle tissue damage, we examined the differential plasma responses of Peptide F to different exercise training programs. Participants were tested pre-training (T1), and after 8 weeks (T2) of training. Fifty-nine healthy women were matched and then randomly assigned to one of four groups: heavy resistance strength training (STR, n = 18), high intensity endurance training (END, n = 14), combined strength and endurance training (CMB, n = 17), or control (CON, n = 10). Blood was collected using a cannula inserted into a superficial vein in the antecubital fossa with samples collected at rest and immediately after an acute bout of 6 X 10 RM in a squat resistance exercise before training and after training. Prior to any training, no significant differences were observed for any of the groups before or after acute exercise. With training, significant (P ≤ 0.95) elevations were observed with acute exercise in each of the exercise training groups and this effect was significantly greater in the CMB group. These data indicate that in untrained women exercise training will not change resting of plasma Peptide F concentrations unless both forms of exercise are performed but will result in significant increases in the immediate post-exercise responses. Such findings appear to indicate adrenal medullary adaptations opioid production significantly altered with exercise training.     

Strength training,but not endurance training,reduces motor unit discharge rate variability

This study evaluates and compares the effects of strength and endurance training on motor unit discharge rate variability and force steadiness of knee extensor muscles. Thirty sedentary healthy men (age, 26.0 ± 3.8 yrs) were randomly assigned to strength training, endurance training or a control group. Conventional endurance and strength training was performed 3 days per week, over a period of 6 weeks. Maximum voluntary contraction (MVC), time to task failure (at 30% MVC), coefficient of variation (CoV) of force and of the discharges rates of motor units from the vastus medialis obliquus and vastus lateralis were determined as subjects performed 20% and 30% MVC knee extension contractions before and after training. CoV of motor unit discharges rates was significantly reduced for both muscles following strength training (P < 0.001), but did not change in the endurance (P = 0.875) or control group (P = 0.995). CoV of force was reduced after the strength training intervention only (P < 0.01). Strength training, but not endurance training, reduces motor unit discharge rate variability and enhances force steadiness of the knee extensors. These results provide new insights into the neuromuscular adaptations that occur with different training methods.     

Effects of developmental exposure to bisphenol A and ethinyl estradiol on spatial navigational learning and memory in painted turtles (Chrysemys picta)

Developmental exposure of turtles and other reptiles to endocrine disrupting chemicals (EDCs), including bisphenol A (BPA) and ethinyl estradiol (EE2, estrogen present in birth control pills), can induce partial to full gonadal sex-reversal in males. No prior studies have considered whether in ovo exposure to EDCs disrupts normal brain sexual differentiation. Yet, rodent model studies indicate early exposure to these chemicals disturbs sexually selected behavioral traits, including spatial navigational learning and memory. Thus, we sought to determine whether developmental exposure of painted turtles (Chrysemys picta) to BPA and EE2 results in sex-dependent behavioral changes. At developmental stage 17, turtles incubated at 26⁰C (male-inducing temperature) were treated with 1) BPA High (100 μg /mL), 2) BPA Low (0.01 μg/mL), 3) EE2 (0.2 μg/mL), or 4) vehicle or no vehicle control groups. Five months after hatching, turtles were tested with a spatial navigational test that included four food containers, only one of which was baited with food. Each turtle was randomly assigned one container that did not change over the trial period. Each individual was tested for 14 consecutive days. Results show developmental exposure to BPA High and EE2 improved spatial navigational learning and memory, as evidenced by increased number of times spent in the correct target zone and greater likelihood of solving the maze compared to control turtles. This study is the first to show that in addition to overriding temperature sex determination (TSD) of the male gonad, these EDCs may induce sex-dependent behavioral changes in turtles.     

Plasma nitrate/nitrite levels are unchanged after long-term aerobic exercise training in older adults

Reduced nitric oxide (NO) production and bioactivity is a major contributor to endothelial dysfunction. Animal data suggest that improvements in endothelial function in response to aerobic exercise training may depend on the duration of the training program. However, no studies have examined changes in NO (as assessed by the major NO metabolites, nitrate and nitrite, NO_x) after long-term training in humans. In addition, aging may impair the ability of the vasculature to increase NO with exercise. Thus, we determined whether 24 weeks of aerobic exercise training increases plasma NO_x levels in sedentary older adults. We also examined changes in forearm blood flow (FBF) at rest and during reactive hyperemia as a measure of vasomotor function. Plasma NO_x levels were measured in 82 men and women using a modified Griess assay. FBF was assessed in a subset of individuals (n = 15) using venous occlusion plethysmography. After 24 weeks of exercise training, there were significant improvements in maximum oxygen consumption, HDL cholesterol, triglycerides, and body fat. Changes in plasma NO_x levels ranged from ?14.83 to +16.69 μmol/L; however, the mean change overall was not significant (?0.33 ± 6.30 μmol/L, p = 0.64). Changes in plasma NO_x levels were not associated with age, gender, race, HDL cholesterol, triglycerides, body weight, body fat, or maximal oxygen consumption. There were also no significant changes in basal FBF, peak FBF, hyperemic response, total hyperemic flow, or minimum forearm vascular resistance with exercise training. In conclusion, improvements in plasma NO_x levels and FBF are not evident after long-term training in older adults.     

δ15N and δ13C diet–tissue discrimination factors for large sharks under semi-controlled conditions

Stable isotopes (δ¹⁵N and δ¹³C) are being widely applied in ecological research but there has been a call for ecologists to determine species- and tissue-specific diet discrimination factors (?¹³C and ?¹⁵N) for their study animals. For large sharks stable isotopes may provide an important tool to elucidate aspects of their ecological roles in marine systems, but laboratory based controlled feeding experiments are impractical. By utilizing commercial aquaria, we estimated ?¹⁵N and ?¹³C of muscle, liver, vertebral cartilage and a number of organs of three large sand tiger (Carcharias taurus) and one large lemon shark (Negaprion brevirostris) under a controlled feeding regime. For all sharks mean ± SD for ?¹⁵N and ?¹³C in lipid extracted muscle using lipid extracted prey data were 2.29‰ ± 0.22 and 0.90‰ ± 0.33, respectively. The use of non-lipid extracted muscle and prey resulted in very similar ?¹⁵N and ?¹³C values but mixing of lipid and non-lipid extracted data produced variable estimates. Values of ?¹⁵N and ?¹³C in lipid extracted liver and prey were 1.50‰ ± 0.54 and 0.22‰ ± 1.18, respectively. Non-lipid extracted diet discrimination factors in liver were highly influenced by lipid content and studies that examine stable isotopes in shark liver, and likely any high lipid tissue, should strive to remove lipid effects through standardising C:N ratios, prior to isotope analysis. Mean vertebral cartilage ?¹⁵N and ?¹³C values were 1.45‰ ± 0.61 and 3.75‰ ± 0.44, respectively. Organ ?¹⁵N and ?¹³C values were more variable among individual sharks but heart tissue was consistently enriched by ~ 1–2.5‰. Minimal variability in muscle and liver δ¹⁵N and δ¹³C sampled at different intervals along the length of individual sharks and between liver lobes suggests that stable isotope values are consistent within tissues of individual animals. To our knowledge, these are the first reported diet–tissue discrimination factors for large sharks under semi-controlled conditions, and are lower than those reported for teleost fish.     

Measurement of clavicular length and shortening after a midshaft clavicular fracture: Spatial digitization versus planar roentgen photogrammetry

Purpose: Clavicular shortening after fracture is deemed prognostic for clinical outcome and is therefore generally assessed on radiographs. It is used for clinical decision making regarding operative or non-operative treatment in the first 2 weeks after trauma, although the reliability and accuracy of the measurements are unclear. This study aimed to assess the reliability of roentgen photogrammetry (2D) of clavicular length and shortening, and to compare these with 3D-spatial digitization measurements, obtained with an electromagnetic recording system (Flock of Birds). Patients and methods: Thirty-two participants with a consolidated non-operatively treated two or multi-fragmented dislocated midshaft clavicular fracture were analysed. Two observers measured clavicular lengths and absolute and proportional clavicular shortening on radiographs taken before and after fracture consolidation. The clavicular lengths were also measured with spatial digitization. Inter-observer agreement on the radiographic measurements was assessed using the Intraclass Correlation Coefficient (ICC). Agreement between the radiographic and spatial digitization measurements was assessed using a Bland–Altman plot. Results: The inter-observer agreement on clavicular length, and absolute and proportional shortening on trauma radiographs was almost perfect (ICC > 0.90), but moderate for absolute shortening after consolidation (ICC = 0.45). The Bland–Altman plot compared measurements of length on AP panorama radiographs with spatial digitization and showed that planar roentgen photogrammetry resulted in up to 37 mm longer and 34 mm shorter measurements than spatial digitization. Conclusion: Measurements of clavicular length on radiographs are highly reliable between observers, but may not reflect the actual length and shortening of the clavicle when compared to length measurements with spatial digitization. We recommend to use proportional shortening when measuring clavicular length or shortening on radiographs for clinical decision making.     

Endurance and strength training effects on physiological and muscular parameters during prolonged cycling

PurposeThis study investigated the effects of a combined endurance and strength training on the physiological and neuromuscular parameters during a 2-h cycling test.MethodsFourteen triathletes were assigned to an endurance-strength training group and an endurance-only training group. They performed three experimental trials before and after training: an incremental cycling test to exhaustion, a maximal concentric lower-limbs strength measurement and a 2-h cycling exercise. Physiological parameters, free cycling chosen cadence and the EMG of Vastus Lateralis (VL) and Rectus Femoris (RF) were analysed during the 2-h cycling task before and after a strength training programme of 5 weeks (three times per week).ResultsThe results showed that the maximum strength and the isometric maximal voluntary contraction (isoMVC) after training were significantly higher (P < 0.01) and lower (P < 0.01) than those before training, respectively, in endurance-strength training group and endurance-only group. The physiological variables measured during the cycling tests and the progressive increase (P < 0.01) in EMGi_(VL) and EMGi_(RF) throughout the 2-h cycling test did not differ between the two groups before and after training, except for the variation of EMGi_(VL) over the cycle time which was stabilized during the second hour of the 2-h cycling test due to training in endurance-strength training group. The decrease in free cycling chosen cadence observed in pre-training (P < 0.01) was also replaced by a steady free cycling chosen cadence for the endurance-strength training group during the second hour of exercise.ConclusionThis study confirmed the decrease in the free cycling chosen cadence with exercise duration and demonstrated that a specific combined endurance and strength training can prevent this decrease during a 2-h constant cycling exercise.     

Effects of exercise training modality on skeletal muscle fatigue in men with coronary heart disease

Cardiopulmonary and skeletal muscle effects of combined aerobic and resistance training vs. aerobic training were studied in men with coronary heart disease. Sixteen men with coronary heart disease underwent a cardiopulmonary exercise testing and a quadriceps skeletal muscle fatigue assessment. Patients were divided into two groups and trained in a combined aerobic and resistance or aerobic training group during 7 weeks. Maximal voluntary contraction and isometric endurance time were measured with electromyographic signals recorded from vastus lateralis (VL), rectus femoris (RF) and vastus medialis (VM) during isometric endurance time. Exercise tolerance increased only in the combined group (p < 0.05). Maximal voluntary contraction and isometric endurance time did not change after training in either group but was performed at 5.8% higher force output for the combined group. After training, median frequency values were higher for the VL and VM (p < 0.001) in the aerobic group and also higher for the VL, RF (p < 0.001) and VM (p < 0.05) in the combined group. Combined aerobic and resistance training was more effective to improve exercise tolerance, decrease skeletal muscle fatigue and correct neuromuscular alterations in men with coronary heart disease.     

Involvement of dorsal hippocampal muscarinic cholinergic receptors on muscimol state-dependent memory of passive avoidance in mice

AimsIn the present study, the effects of bilateral intra-dorsal hippocampal (intra-CA1) injections of cholinergic agents on muscimol state-dependent memory were examined in mice.Main methodsA single-trial step-down passive avoidance task was used for the assessment of memory retention in adult male NMRI mice.Key findingsPre-training intra-CA1 administration of a GABA-A receptor agonist, muscimol (0.05 and 0.1 μg/mouse) dose dependently induced impairment of memory retention. Pre-test injection of muscimol (0.05 and 0.1 μg/mouse, intra-CA1) induced state-dependent retrieval of the memory acquired under pre-training muscimol (0.1 μg/mouse, intra-CA1) influence. Pre-test intra-CA1 injection of an acetylcholinesterase inhibitor, physostigmine (0.5 and 1 μg/mouse, intra-CA1) reversed the memory impairment induced by pre-training administration of muscimol (0.1 μg/mouse, intra-CA1). Moreover, pre-test administration of physostigmine (0.5 and 1 μg/mouse, intra-CA1) with an ineffective dose of muscimol (0.025 μg/mouse, intra-CA1) significantly restored the retrieval and induced muscimol state-dependent memory. Pre-test intra-CA1 administration of physostigmine (0.25, 0.5 and 1 μg/mouse) by itself cannot affect memory retention. Pre-test intra-CA1 injection of the muscarinic receptor antagonist, atropine (1 and 2 μg/mouse) 5 min before the administration of muscimol (0.1 μg/mouse, intra-CA1) dose dependently inhibited muscimol state-dependent memory. Pre-test intra-CA1 administration of atropine (0.5, 1 and 2 μg/mouse) by itself cannot affect memory retention.SignificanceThe results suggest that muscarinic cholinergic mechanism of the CA1 may influence muscimol state-dependent memory.     

Carnosine ameliorates cognitive deficits in streptozotocin-induced diabetic rats: Possible involved mechanisms

Diabetic patients are at increased risk to develop cognitive deficit and senile dementia. This study was planned to assess the benefits of chronic carnosine administration on prevention of learning and memory deterioration in streptozotocin (STZ)-diabetic rats and to explore some of the involved mechanisms. Rats were divided into 5 groups: i.e., control, carnosine100-treated control, diabetic, and carnosine-treated diabetics (50 and 100 mg/kg). Carnosine was injected i.p. at doses of 50 or 100 mg/kg for 7 weeks, started 1 week after induction of diabetes using streptozotocin. Treatment of diabetic rats with carnosine at a dose of 100 mg/kg at the end of the study lowered serum glucose, improved spatial recognition memory in Y maze, improved retention and recall in elevated plus maze, and prevented reduction of step-through latency in passive avoidance task. Furthermore, carnosine at a dose of 100 mg/kg reduced hippocampal acetylcholinesterase (AChE) activity, lowered lipid peroxidation, and improved superoxide dismutase (SOD) activity and non-enzymatic antioxidant defense element glutathione (GSH), but not activity of catalase. Meanwhile, hippocampal level of nuclear factor-kappaB (NF-κB), tumor necrosis factor α (TNF-α), and glial fibrillary acidic protein (GFAP) decreased and level of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and heme oxygenase 1 (HO-1) increased upon treatment of diabetic group with carnosine at a dose of 100 mg/kg. Taken together, chronic carnosine treatment could ameliorate learning and memory disturbances in STZ-diabetic rats through intonation of NF-κB/Nrf2/HO-1 signaling cascade, attenuation of astrogliosis, possible improvement of cholinergic function, and amelioration of oxidative stress and neuroinflammation.     

Depot-specific modulation of adipokine levels in rat adipose tissue by diet-induced obesity: The effect of aerobic training and energy restriction

The present study examined the effects of aerobic training and energy restriction on adipokines levels in mesenteric (MEAT) and retroperitoneal (RPAT) white adipose tissue from obese rats. Male Wistar rats were fed with standard laboratory diet (Control group) or high fat diet (HFD). After 15 weeks, HFD rats were randomly assigned to the following groups: rats submitted to HFD, which were sedentary (sedentary HFD, n = 8) or trained (trained HFD, n = 8); or submitted to energy-restriction (ER), which were sedentary (sedentary ER, n = 8) or trained (trained ER, n = 8). Trained rats ran on a treadmill at 55% VO_2max for 60 min/day, 5 days/week, for 10 weeks. ER rats were submitted to a reduction of 20% daily caloric ingestion compared to the Control group. ER and aerobic training decreased body weight, MEAT and RPAT absolute weight, and fat mass. IL-6, IL-10 and TNF-α levels were decreased and adiponectin did not change in RPAT in response to ER protocol. On the other hand, ER and the aerobic training protocol decreased IL-6, TNF-α and adiponectin levels in MEAT. Absolute MEAT weight showed a positive correlation with IL-6 (r = 0.464), TNF-α (r = 0.508); and adiponectin (r = 0.342). These results suggest a tissue-specific heterogeneous response in adipokines level. The combination of the protocols (aerobic training and energy restriction) did not induce an enhanced effect.     

Positive impact of levetiracetam on emotional learning and memory in naive mice

AimsThe effect of an antiepileptic drug on cognitive function is of primary importance with respect to the patient's quality of life. Levetiracetam (LEV) is a novel antiepileptic drug used to treat epilepsy, but its effects on spatial and emotional learning and memory are not yet well understood. The goal of our study was to establish the effects of LEV (17 and 54 mg/kg, intraperitoneally (IP)) on spatial memory retrieval in the Morris water maze test and on acquisition and memory formation in the passive avoidance (PA) test in naive mice.Main methodsThe subjects were adult male BALB/c mice. Spatial learning and memory was established with the Morris water maze (MWM) test. The ‘time spent in escape platforms quadrant’ and the ‘distance to platform’ analyses were measured using a video tracking system to determine spatial memory function. Emotional learning and memory were determined with a one-trial, step-through passive avoidance test.Key findingsIn the MWM test, LEV (17 and 54 mg/kg) neither affected the time spent in the target quadrant nor altered the distance to platform. Moreover, LEV had no effect on swim speed. In the PA task, LEV (17 and 54 mg/kg) significantly prolonged retention latency.SignificanceOur results indicate that LEV did not alter spatial memory retrieval in the MWM test, but it did show some ameliorating effects on acquisition and memory formation in the PA test in naive mice.     

Quantitative evaluation of motor functional recovery process in chronic stroke patients during robot-assisted wrist training

This study was to investigate the motor functional recovery process in chronic stroke during robot-assisted wrist training. Fifteen subjects with chronic upper extremity paresis after stroke attended a 20-session wrist tracking training using an interactive rehabilitation robot. Electromyographic (EMG) parameters, i.e., EMG activation levels of four muscles: biceps brachii (BIC), triceps brachii (TRI, lateral head), flexor carpiradialis (FCR), and extensor carpiradialis (ECR) and their co-contraction indexes (CI) were used to monitor the neuromuscular changes during the training course. The EMG activation levels of the FCR (11.1% of decrease from the initial), BIC (17.1% of decrease from the initial), and ECR (29.4% of decrease from the initial) muscles decreased significantly during the training (P < 0.05). Such decrease was associated with decreased Modified Ashworth Scores for both the wrist and elbow joints (P < 0.05). Significant decrease (P < 0.05) was also found in CIs of muscle pairs, BIC&TRI (21% of decrease from the initial), FCR&BIC (11.3% of decrease from the initial), ECR&BIC (49.3% of decrease from the initial). The decreased CIs related to the BIC muscle were mainly caused by the reduction in the BIC EMG activation level, suggesting a better isolation of the wrist movements from the elbow motions. The decreased CI of ECR& FCR in the later training sessions (P < 0.05) was due to the reduced co-contraction phase of the antagonist muscle pair in the tracking tasks. Significant improvements (P < 0.05) were also found in motor outcomes related to the shoulder/elbow and wrist/hand scores assessed by the Fugl–Meyer assessment before and after the training. According to the evolution of the EMG parameters along the training course, further motor improvements could be obtained by providing more training sessions, since the decreases of the EMG parameters did not reach a steady state before the end of the training. The results in this study provided an objective and quantitative EMG measure to describe the motor recovery process during poststroke robot-assisted wrist for the further understanding on the neuromuscular mechanism associated with the recovery.