Direct and indirect connections between cochlear root neurons and facial motor neurons: Pathways underlying the acoustic pinna reflex in the albino rat

Cochlear root neurons (CRNs) are involved in the acoustic startle reflex, which is widely used in behavioral models of sensorimotor integration. A short-latency component of this reflex, the auricular reflex, promotes pinna movements in response to unexpected loud sounds. However, the pathway involved in the auricular component of the startle reflex is not well understood. We hypothesized that the auricular reflex is mediated by direct and indirect inputs from CRNs to the motoneurons responsible for pinna movement, which are located in the medial subnucleus of the facial motor nucleus (Mot7). To assess whether there is a direct connection between CRNs and auricular motoneurons in the rat, two neuronal tracers were used in conjunction: biotinylated dextran amine, which was injected into the cochlear nerve root, and Fluoro-Gold, which was injected into the levator auris longus muscle. Under light microscopy, close appositions were observed between axon terminals of CRNs and auricular motoneurons. The presence of direct synaptic contact was confirmed at the ultrastructural level. To confirm the indirect connection, biotinylated dextran amine was injected into the auditory-responsive portion of the caudal pontine reticular nucleus, which receives direct input from CRNs. The results confirm that the caudal pontine reticular nucleus also targets the Mot7 and that its terminals are concentrated in the medial subnucleus. Therefore, it is likely that CRNs innervate auricular motoneurons both directly and indirectly, suggesting that these connections participate in the rapid auricular reflex that accompanies the acoustic startle reflex. © 2008 Wiley-Liss, Inc.

Desenvolvimento motor de criança com paralisia cerebral: Avaliação e intervenção

The objective of this study was to analyze the motor development of a ten year old child with ataxic cerebral palsy and the effects of a motor activities program in the swimming pool. Motor development was measured according to the motor assessment and the intervention program of motor activities in the swimming pool conducted at Sesi/Londrina, twice a week, during 45 minute sessions over a 2 month period, with an attendance rate of 87%. Data was analyzed descriptively comparing the results with before and after tests. Generally, the motor quotient regarding all items was classified as very low, characterizing motor deficit, with exception of temporal organization, presented as normal low. After intervention, the only area that showed positive change was balance; this result showed that the child gained 12 months in motor age, without corresponding alterations in the other areas.

A structure excited by a DC motor of limited power supply and controlled by a pendulum like device

In this paper, a mathematical model is derived via Lagrange's Equation for a shear building structure that acts as a foundation of a non-ideal direct current electric motor, controlled by a mass loose inside a circular carving. Non-ideal sources of vibrations of structures are those whose characteristics are coupled to the motion of the structure, not being a function of time only as in the ideal case. Thus, in this case, an additional equation of motion is written, related to the motor rotation, coupled to the equation describing the horizontal motion of the shear building. This kind of problem can lead to the so-called Sommerfeld effect: steady state frequencies of the motor will usually increase as more power (voltage) is given to it in a step-by-step fashion. When a resonance condition with the structure is reached, the better part of this energy is consumed to generate large amplitude vibrations of the foundation without sensible change of the motor frequency as before. If additional increase steps in voltage are made, one may reach a situation where the rotor will jump to higher rotation regimes, no steady states being stable in between. As a device of passive control of both large amplitude vibrations and the Sommerfeld effect, a scheme is proposed using a point mass free to bounce back and forth inside a circular carving in the suspended mass of the structure. Numerical simulations of the model are also presented Copyright © 2007 by ASME.

Clinical and microbiological evaluation of the use of toothpaste containing 1% chlorhexidine and the influence of motivation on oral hygiene in patients with motor deficiency

Patients with motor deficiency have variable difficulties with mechanical plaque control, and as a consequence, the incidence of dental caries and periodontal disease can be higher in these patients. The objective of this study was to evaluate the clinical and microbiological efficacy of a toothpaste containing 1% chlorhexidine, which was used by patients with motor deficiency for 14 days. The reduction in plaque and gingival index and the impact on salivary microorganisms was evaluated. We conclude that the motivation of caregivers to carry out oral hygiene for patients with mental and motor deficiency is of great importance and is effective in reducing the formation of plaque as long as it is continuously reinforced. The use of chlorhexidine- containing toothpaste significantly reduced the plaque index and microorganism count between days 0 and 14. A reduction was also observed in the group that used a dentifrice without the chlorhexidine, but this difference was not significant. © 2010 Special Care Dentistry Association and Wiley Periodicals, Inc.

Delay time detection and accommodation for a networked DC motor control

This paper presents a control method that is effective to reduce the degenerative effects of delay time caused by a treacherous network. In present application a controlled DC motor is part of an inverted pendulum and provides the equilibrium of this system. The control of DC motor is accomplished at the distance through a treacherous network, which causes delay time in the control signal. A predictive technique is used so that it turns the system free of delay. A robust digital sliding mode controller is proposed to control the free-delay system. Due to the random conditions of the network operation, a delay time detection and accommodation strategy is also proposed. A computer simulation is shown to illustrate the design procedures and the effectiveness of the proposed method. © 2011 IEEE.

Performance of children with learning difficulties in fine motor function and handwriting

This study aimed to compare and characterize the fine, sensory and perceptive function performance and handwriting quality between students with learning difficulties and students with good academic performance. Methods: This study comprised 192 students from 2nd to 4th grades, both genders, whose ages ranged from 7 to 11 years old. The students were distributed into: GI, GII, GIII and GIV, comprising 96 students with learning difficulties, and groups GV, GVI, GVII, GVIII comprising 96 students with good academic performance. The students were submitted to evaluation of fine motor, sensorial and perception functions and handwriting evaluation under dictation. Results: The results showed that the students with learning difficulties, from 1st to 3rd grade, had lower performance on tests of fine motor, sensory and perceptive function, when compared to the students with good academic performance in the same grade; the students from 4th grade, both groups, did not show changes on fine motor, sensory and perceptive function; and only the students of GII showed dysgraphia. Conclusions: the results presented in this study suggest that the qualitative aspects of fine motor, sensory and perceptive skills reflect the integrity and maturity of central nervous system and can probably play an important role in early diagnosis of development disorders and consequently prevent academic disorders such as handwriting performance.

Bothropstoxin-I reduces evoked acetylcholine release from rat motor nerve terminals: Radiochemical and real-time video-microscopy studies

Understanding the biological activity profile of the snake venom components is fundamental for improving the treatment of snakebite envenomings and may also contribute for the development of new potential therapeutic agents. In this work, we tested the effects of BthTX-I, a Lys49 PLA2 homologue from the Bothrops jararacussu snake venom. While this toxin induces conspicuous myonecrosis by a catalytically independent mechanism, a series of in vitro studies support the hypothesis that BthTX-I might also exert a neuromuscular blocking activity due to its ability to alter the integrity of muscle cell membranes. To gain insight into the mechanisms of this inhibitory neuromuscular effect, for the first time, the influence of BthTX-I on nerve-evoked ACh release was directly quantified by radiochemical and real-time video-microscopy methods. Our results show that the neuromuscular blockade produced by in vitro exposure to BthTX-I (1 μM) results from the summation of both pre- and postsynaptic effects. Modifications affecting the presynaptic apparatus were revealed by the significant reduction of nerve-evoked [3H]-ACh release; real-time measurements of transmitter exocytosis using the FM4-64 fluorescent dye fully supported radiochemical data. The postsynaptic effect of BthTX-I was characterized by typical histological alterations in the architecture of skeletal muscle fibers, increase in the outflow of the intracellular lactate dehydrogenase enzyme and progressive depolarization of the muscle resting membrane potential. In conclusion, these findings suggest that the neuromuscular blockade produced by BthTX-I results from transient depolarization of skeletal muscle fibers, consequent to its general membrane-destabilizing effect, and subsequent decrease of evoked ACh release from motor nerve terminals. © 2012 Elsevier Ltd.

Trade openness and structural change in the Brazilian motor industry

Includes bibliography

Desempenho motor de aluno com paralisia cerebral discinética frente à adaptação das propriedades físicas de recurso pedagógico

The main purpose of this study was to analyze the modified physical properties of an educational resource for facilitating the handling of a child with dyskinetic cerebral palsy. The participant of the study was a six year old child with dyskinetic cerebral palsy enrolled in a regular early childhood education classroom. The educational resource that was selected was a brick game, in which the physical properties of weight, size and texture had been modified. The analysis was made regarding the quality of upper limb movement to the variables: righting index, scalar displacement (s), average speed (As) and time (t). The results showed that combined large size and heavy weight did not have a satisfactory outcome, affecting both grasping the educational resource and fitting. There was also inconsistency in children with cerebral palsy's responses. There is variation in the results, though a standard cannot be established. Thus, this study contributed to understanding the motor responses of a child with dyskinetic cerebral palsy when participating in a fitting activity with educational resources in which the physical properties had been modified.

Motor Recovery and Synaptic Preservation after Ventral Root Avulsion and Repair with a Fibrin Sealant Derived from Snake Venom

Background:Ventral root avulsion is an experimental model of proximal axonal injury at the central/peripheral nervous system interface that results in paralysis and poor clinical outcome after restorative surgery. Root reimplantation may decrease neuronal degeneration in such cases. We describe the use of a snake venom-derived fibrin sealant during surgical reconnection of avulsed roots at the spinal cord surface. The present work investigates the effects of this fibrin sealant on functional recovery, neuronal survival, synaptic plasticity, and glial reaction in the spinal motoneuron microenvironment after ventral root reimplantation.Methodology/Principal Findings:Female Lewis rats (7 weeks old) were subjected to VRA and root replantation. The animals were divided into two groups: 1) avulsion only and 2) replanted roots with fibrin sealant derived from snake venom. Post-surgical motor performance was evaluated using the CatWalk system twice a week for 12 weeks. The rats were sacrificed 12 weeks after surgery, and their lumbar intumescences were processed for motoneuron counting and immunohistochemistry (GFAP, Iba-1 and synaptophysin antisera). Array based qRT-PCR was used to evaluate gene regulation of several neurotrophic factors and receptors as well as inflammatory related molecules. The results indicated that the root reimplantation with fibrin sealant enhanced motor recovery, preserved the synaptic covering of the motoneurons and improved neuronal survival. The replanted group did not show significant changes in microglial response compared to VRA-only. However, the astroglial reaction was significantly reduced in this group.Conclusions/Significance:In conclusion, the present data suggest that the repair of avulsed roots with snake venom fibrin glue at the exact point of detachment results in neuroprotection and preservation of the synaptic network at the microenvironment of the lesioned motoneurons. Also such procedure reduced the astroglial reaction and increased mRNA levels to neurotrophins and anti-inflammatory cytokines that may in turn, contribute to improving recovery of motor function. © 2013 Barbizan et al.

Speed estimation for induction motor using neural networks method

This work presents an alternative approach based on neural network method in order to estimate speed of induction motors, using the measurement of primary variables such as voltage and current. Induction motors are very common in many sectors of the industry and assume an important role in the national energy policy. The nowadays methodologies, which are used in diagnosis, condition monitoring and dimensioning of these motors, are based on measure of the speed variable. However, the direct measure of this variable compromises the system control and starting circuit of an electric machinery, reducing its robustness and increasing the implementation costs. Simulation results and experimental data are presented to validate the proposed approach. © 2003-2012 IEEE.

Effect of muscle fatigue and physical activity level in motor control of the gait of young adults

The aim of this study was to analyze the effect of muscle fatigue in active and inactive young adults on the kinematic and kinetic parameters of normal gait and obstacle crossing. Twenty male subjects were divided into active (10) and inactive (10), based on self-reported physical activity. Participants performed three trials of two tasks (normal gait and obstacle crossing) before and after a fatigue protocol, consisting of repeated sit-to-stand transfers until the instructed pace could no longer be maintained. MANOVAs were used to compare dependent variables with the following factors: physical activity level, fatigue and task. The endurance time in the fatigue protocol was lower for the inactive group. Changes of gait parameters with fatigue, among which increased step width and increased stride speed were the most consistent, were independent of task and physical activity level. These findings indicate that the kinematic and kinetic parameters of gait are affected by muscle fatigue irrespective of the physical activity level of the subjects and type of gait. Inactive individuals used a slightly different strategy than active individuals when crossing an obstacle, independently of muscle fatigue. © 2013.

Motor intervention in children with school learning difficulties

This study sought to evaluate motor development in children aged 6 to 11 years with learning difficulties and school characteristics of delayed motor development, before and after application of a motor intervention program. The sample consisted of 28 children with a mean age of 107.21 ± 16.56 months, who were evaluated by the Motor Development Scale and received motor intervention for 6 months, followed by reassessment. We observed a statistically significant difference between the average of the motor activity ratios in all areas of the evaluation and reevaluation. Also verified in the evaluation were the concentration ratios of children with motor activity greater than or equal to 80 and there was a revaluation increase in this concentration on re-evaluation, the areas with the greatest increase in concentration and significant differences being: Body Schema, Space and temporal Organization. In the overall evaluation of MDS, most children presented the classification of low normal. However, in the reassessment most have evolved into the average normal, only 4 of themremaining in the same classification. Therefore, in this study, children with learning disabilities also showed motor deficits and the intervention applied contributed to an increase in the motor ratios with consequent improvement in motor development. Besides psychopedagogical asistance, it is essential to reassess them and if necessary apply the intervention in the motor development of children with learning difficulties.

Motor readiness and joint torque production in lower limbs of older women fallers and non-fallers

This study aimed to evaluate the motor response time and ability to develop joint torque at the knee and ankle in older women with and without a history of falls, in addition to investigating the effect of aging on these capacities. We assessed 18 young females, 21 older female fallers and 22 older female non-fallers. The peak torque, rate of torque development, rate of electromyography (EMG) rise, reaction time, premotor time and motor time were obtained through a dynamometric assessment and simultaneous electromyography. Surface EMGs of the rectus femoris (RF), vastus lateralis (VL), biceps femoris (BF), gastrocnemius lateralis (GL) and tibialis anterior (TA) muscles were recorded. Knee extension and flexion peak torques were lower in older fallers than in non-fallers. Knee extension and flexion and ankle plantarflexion and dorsiflexion peak torques were lower in both older groups than in the younger group. The rate of EMG rise of the BF and the motor time of the TA were lower and higher, respectively, in older fallers than in the younger adults. The time to reach peak torque in knee extension/flexion and ankle plantarflexion/dorsiflexion and the motor times of the RF, VL, BF and GL were higher in both older groups than in the younger groups. The motor time of the TA during ankle dorsiflexion and the knee extension peak torque were the major predictors of falls in older women, accounting for approximately 28% of the number of falls. Thus, these results further reveal the biomechanical parameters that affect the risk of falls and provide initial findings to support the prescription of exercises in fall prevention programs. © 2013 Elsevier Ltd.

Modelagem de um motor de indução trifásico operando com tensões desequilibradas por meio de redes neurais artificiais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)