Selective activation of the right hippocampus during navigation by spatial cues in domestic chicks (Gallus gallus).

In different vertebrate species, hippocampus plays a crucial role for spatial orientation. However, even though cognitive lateralization is widespread in the animal kingdom, the lateralization of this hippocampal function has been poorly studied. The aim of the present study was to investigate the lateralization of hippocampal activation in domestic chicks, during spatial navigation in relation to free-standing objects. Two groups of chicks were trained to find food in one of the feeders located in a large circular arena. Chicks of one group solved the task using the relational spatial information provided by free-standing objects present in the arena, while the other group used the local appearance of the baited feeder as a beacon. The immediate early gene product c-Fos was employed to map neural activation of hippocampus and medial striatum of both hemispheres. Chicks that used spatial cues for navigation showed higher activation of the right hippocampus compared to chicks that oriented by local features and compared to the left hippocampus. Such differences between the two groups were not present in the left hippocampus or in the medial striatum. Relational spatial information seems thus to be selectively processed by the right hippocampus in domestic chicks. The results are discussed in light of existing evidence of hippocampal lateralization of spatial processing in chicks, with particular attention to the contrasting evidence found in pigeons.

Optical flow analysis reveals that Kinesin-mediated advection impacts the orientation of microtubules in the Drosophila oocyte.

The orientation of microtubule (MT) networks is exploited by motors to deliver cargoes to specific intracellular destinations and is thus essential for cell polarity and function. Reconstituted in vitro systems have largely contributed to understanding the molecular framework regulating the behavior of MT filaments. In cells, however, MTs are exposed to various biomechanical forces that might impact on their orientation, but little is known about it. Oocytes, which display forceful cytoplasmic streaming, are excellent model systems to study the impact of motion forces on cytoskeletons in vivo. Here we implement variational optical flow analysis as a new approach to analyze the polarity of MTs in the Drosophila oocyte, a cell that displays distinct Kinesin-dependent streaming. After validating the method as robust for describing MT orientation from confocal movies, we find that increasing the speed of flows results in aberrant plus end growth direction. Furthermore, we find that in oocytes where Kinesin is unable to induce cytoplasmic streaming, the growth direction of MT plus ends is also altered. These findings lead us to propose that cytoplasmic streaming - and thus motion by advection - contributes to the correct orientation of MTs in vivo. Finally, we propose a possible mechanism for a specialized cytoplasmic actin network (the actin mesh) to act as a regulator of flow speeds to counteract the recruitment of Kinesin to MTs.

O nível de atividade física como um fator interveniente no estado cognitivo de idosos da atenção básica à saúde / The level of physical activity as an intervening factor in the cognitive state of primary care older adults

Resumo Este estudo propôs a avaliar o nível de atividade física e o estado cognitivo de idosos usuários das Unidades Básicas de saúde (UBS) do Município de Maringá, Paraná. Trata-se de um estudo epidemiológico descritivo, de corte observacional e transversal, realizado com 654 idosos, de ambos os sexos, usuários das UBS. Foi utilizado um questionário sociodemográfico, o Mini exame do estado mental e o International Activity Questionnaire (IPAQ), versão curta. A análise dos dados foi realizada mediante o teste Kolmogorov-Smirnov, Qui quadrado, Kruskal-Wallis e "U" de Mann-Whitney, adotando significância quando p < 0,05. Os idosos não realizam atividades físicas vigorosas e poucas atividades moderadas durante a semana. Porém, apresentaram alto escore na orientação temporal (Md = 5,0), Orientação espacial (Md = 5,0), memória imediata (Md = 3,0), evocação (Md = 3,0) e linguagem (Md = 8,0). Ao comparar o estado mental em função do nível de atividade física dos idosos verificou-se que os Muito ativo/ativo possuem melhor atenção e cálculo (p = 0,036), evocação (p = 0,001) e estado cognitivo geral (p = 0,002), se comparado aos irregularmente ativos e sedentários. Níveis adequados de atividade física podem estar relacionados a melhores escores de funções cognitivas de sujeitos idosos.

Abstract This study proposed to evaluate the level of physical activity and the cognitive state of elderly users of Primary Care Facilities (UBS) of the Municipality of Maringá, State of Paraná, Brazil. This is a descriptive, cross-sectional, epidemiological study with 654 elderly men and women UBS users. A sociodemographic questionnaire, the Mini Mental State Examination (MMSE) and the short version of the International Physical Activity Questionnaire (IPAQ) were employed. Data was analyzed using the Kolmogorov-Smirnov, Chi-square, Kruskal-Wallis and Mann-Whitney "U" tests, with a significance level of p<0.05. However, they evidenced a high score in temporal orientation (Md = 5.0), spatial orientation (Md = 5.0), immediate memory (Md = 3.0), recall (Md = 3.0) and language (Md = 8.0). When comparing the mental state according to the level of physical activity of the elderly, we observed that very active/active individuals had better attention and calculation (p = 0.036), recall (p = 0.001) and general cognitive status (p = 0.002) against irregularly active and sedentary elderly. Adequate levels of physical activity may be related to better scores of cognitive functions of elderly subjects.

Minimum predicted distance: Applying a common metric to collision avoidance strategies between children and adult walkers.

BACKGROUND: Collision avoidance between two walkers involves a mutual adaptation to speed and orientation in order to successfully avoid a collision. Minimum Predicted Distance (MPD) is the distance at which two walkers would collide if their speed and path trajectory were maintained at first sight of one another. MPD has been used to describe the risk of collision and its evolution over time between two adult walkers when on a collision course. Middle-aged children have been shown to have poor perception-action coupling during static and dynamic collision avoidance tasks. Research has yet to examine whether perception-action coupling deficits persist in a dynamic collision avoidance task involving a child and another walker. RESEARCH QUESTION: Can the metric MPD(t) be used to examine collision avoidance strategies between children and adults? METHODS: Eighteen children (age: 10 ±â€¯1.5 years) and eighteen adults (34 ±â€¯9.6 years) walked along a 12.6 m pathway while avoiding another participant (child or adult). Groups of three children and three adults were recruited per session. Trials were randomized equally such that each adult interacted with another adult 20 times, each child interacted with another child 20 times, and each adult interacted with a child 21 times, for a total of 141 trials. 3D kinematic data of each participant's head was recorded using the Vicon system. RESULTS: The results demonstrated: (1) MPD(t) can be used to predict future collisions in children, (2) MPD(t) is an absolute measure that is consistently lower when a child is involved compared to two adult walkers, (3) the individual passing second, even when it is a child, contributes more to MPD(t) than the walker passing first. SIGNIFICANCE: It appears children have developed adult-like strategies during a collision avoidance task involving two walkers. Body anthropometrics should be considered when determining collision avoidance strategies between children and adults.

Revealing Dissociable Attention Biases in Chronic Smokers Through an Individual-Differences Approach.

Addiction is accompanied by attentional biases (AB), wherein drug-related cues grab attention independently of their perceptual salience. AB have emerged in different flavours depending on the experimental approach, and their clinical relevance is still debated. In chronic smokers we sought evidence for dissociable attention abnormalities that may play distinct roles in the clinical manifestations of the disorder. Fifty smokers performed a modified visual probe-task measuring two forms of AB and their temporal dynamics, and data on their personality traits and smoking history/status were collected. Two fully dissociable AB effects were found: A Global effect, reflecting the overall impact of smoke cues on attention, and a Location-specific effect, indexing the impact of smoke cues on visuospatial orienting. Importantly, the two effects could be neatly separated from one another as they: (i) unfolded with dissimilar temporal dynamics, (ii) were accounted for by different sets of predictors associated with personality traits and smoking history and (iii) were not correlated with one another. Importantly, the relevance of each of these two components in the single individual depends on a complex blend of personality traits and smoking habits, a result that future efforts addressing the clinical relevance of addiction-related AB should take into careful consideration.

Impact of orthognathic surgery on the body posture.

BACKGROUND: Postural control is classically described as being based on the visual, vestibular, and proprioceptive musculo-articular sensory systems. The influence of mandibular proprioception on postural stabilization remains controversial. Most previous studies analyzed how postural stability is influenced by partial changes in mandibular proprioception (dental occlusion and jaw position). RESEARCH QUESTION: In the present experiment, we asked whether drastic mandibular changes, resulting from orthognathic surgery (including dental, joint and muscular efferents), modify postural control. METHODS: The analyzes were performed in 22 patients tested before, and 2.5 months, after orthognathic surgery for treatment of dysmorphic jaws. Experiments were performed under 4 experimental conditions: 2 visual conditions: Eyes Open (EO) and Eyes Closed (EC), and 2 occlusal conditions: Occlusion (OC: mandible positioned by the contact of the teeth), and Rest Position (RP: mandible positioned by the muscles without tooth contact). The analyses focused on head orientation in the frontal plane and on postural stabilization in a static task, consisting of standing upright. RESULTS: The results show that, 2.5 months after orthognathic surgery, head orientation in the frontal plane was improved, since patient's external intercanthal lines became closer to the true horizontal line when they were tested EC and in OC condition. Postural responses, based on the wavelet transformation data, highlight an improvement in maintaining an upright stance for all the tested sensory conditions. However, such improvement was greater in the EC and RP conditions. SIGNIFICANCE: These results show, for the first time, that after drastic mandibular changes, the weight of proprioceptive cues linked to the mandibular system may be so enhanced that it may constitute a new reference frame to orient the head in space, in darkness, and improve static postural stabilization, even in the presence of visual cues.

Don't neglect the clock drawing test.

INTRODUCTION: A 63-year-old, right-handed woman with a history of hypertension presented to the ED with left arm paresis of 2 days duration. Three weeks before admission, she had flu-like symptoms with intermittent left arm weakness that had recovered briefly but recurred 2 days prior to her presentation. On neurological examination, GCS was 15 and cranial nerves' function was normal. Left upper limb strength was 4/5. There was left arm drift and pronation but the patient denied noticing any difference between the positions of her arms. Hyper-reflexion was presented in the left arm. The rest of her motor, cerebellar, sensation and gait functions were normal. She was asked to draw a clock and set it to 15:30 (figure 1).emermed;35/1/38/F1F1F1Figure 1Clock drawing test results. QUESTION: What is the most probable aetiology?Right cerebral bleeding involving the occipital lobeRight middle cerebral artery occlusionRight parietal lesion, likely neoplasmLeft cortical stroke.

Subjective visual vertical after treatment of benign paroxysmal positional vertigo / Vertical visual subjetiva após tratamento da vertigem posicional paroxística benigna

Abstract Introduction: Otolith function can be studied by testing the subjective visual vertical, because the tilt of the vertical line beyond the normal range is a sign of vestibular dysfunction. Benign paroxysmal positional vertigo is a disorder of one or more labyrinthine semicircular canals caused by fractions of otoliths derived from the utricular macula. Objective: To compare the subjective visual vertical with the bucket test before and immediately after the particle repositioning maneuver in patients with benign paroxysmal positional vertigo. Methods: We evaluated 20 patients. The estimated position where a fluorescent line within a bucket reached the vertical position was measured before and immediately after the particle repositioning maneuver. Data were tabulated and statistically analyzed. Results: Before repositioning maneuver, 9 patients (45.0%) had absolute values of the subjective visual vertical above the reference standard and 2 (10.0%) after the maneuver; the mean of the absolute values of the vertical deviation was significantly lower after the intervention (p < 0.001). Conclusion: There is a reduction of the deviations of the subjective visual vertical, evaluated by the bucket test, immediately after the particle repositioning maneuver in patients with benign paroxysmal positional vertigo.

Resumo Introdução: A função do otólito pode ser estudada por meio de testes da vertical visual subjetiva, porque a inclinação da linha vertical além da faixa normal é um sinal de disfunção vestibular. A vertigem postural paroxística benigna é um distúrbio de um ou mais canais semicirculares labirínticos causado por frações de otólitos derivados da mácula utricular. Objetivo: Comparar a vertical visual subjetiva com o teste do balde antes e imediatamente após a manobra de reposicionamento de partículas em pacientes com vertigem posicional paroxística benigna. Método: Foram avaliados 20 pacientes. A posição estimada, onde uma linha de fluorescência dentro de um balde atingia a posição vertical, foi medida antes e imediatamente após a manobra de reposicionamento de partículas. Os dados foram tabulados e analisados estatisticamente. Resultados: Antes da manobra de reposicionamento, nove pacientes (45%) apresentaram valores absolutos de vertical visual subjetiva acima da referência padrão e dois (10%) depois da manobra; a média dos valores absolutos do desvio vertical foi significativamente mais baixa depois da intervenção (p < 0,001). Conclusão: Há uma redução dos desvios da vertical visual subjetiva, avaliada pelo teste do balde, imediatamente após a manobra de reposicionamento de partículas em pacientes com vertigem posicional paroxística benigna.

Gonadotropin-releasing hormone receptor (Gnrhr) gene knock out: Normal growth and development of sensory, motor and spatial orientation behavior but altered metabolism in neonatal and prepubertal mice.

Gonadotropin-releasing hormone (GnRH) is important in the control of reproduction, but its actions in non-reproductive processes are less well known. In this study we examined the effect of disrupting the GnRH receptor in mice to determine if growth, metabolism or behaviors that are not associated with reproduction were affected. To minimize the effects of other hormones such as FSH, LH and sex steroids, the neonatal-prepubertal period of 2 to 28 days of age was selected. The study shows that regardless of sex or phenotype in the Gnrhr gene knockout line, there was no significant difference in the daily development of motor control, sensory detection or spatial orientation among the wildtype, heterozygous or null mice. This included a series of behavioral tests for touch, vision, hearing, spatial orientation, locomotory behavior and muscle strength. Neither the daily body weight nor the final weight on day 28 of the kidney, liver and thymus relative to body weight varied significantly in any group. However by day 28, metabolic changes in the GnRH null females compared with wildtype females showed a significant reduction in inguinal fat pad weight normalized to body weight; this was accompanied by an increase in glucose compared with wildtype females shown by Student-Newman-Keuls Multiple Comparison test and Student's unpaired t tests. Our studies show that the GnRH-GnRHR system is not essential for growth or motor/sensory/orientation behavior during the first month of life prior to puberty onset. The lack of the GnRH-GnRHR axis, however, did affect females resulting in reduced subcutaneous inguinal fat pad weight and increased glucose with possible insulin resistance; the loss of the normal rise of estradiol at postnatal days 15-28 may account for the altered metabolism in the prepubertal female pups.

Is orienteering associated with allergic rhinitis in adolescents?

BACKGROUND: Allergic rhinitis (AR) is a disease that reduces athletic performance. Environmental allergen exposure is higher in outdoor sports (such as orienteering) than indoor sports. The main purpose of this study was to investigate the AR frequency in orienteers comparing with indoor athletes. METHODS: Sixty adolescent athletes (33 orienteers, 27 basketball players) enrolled this prospective study. AR diagnosis was made by both history (ISAAC questionnaire) and physical examination. Nasal endoscopy was performed to observe objective findings (concha hypertrophy, mucosal paleness, serosity, septum deviation, adenoid hypertrophy). Epidermal prick test, pulmonary function test, total IgE and serum eosinophil levels were also assessed. RESULTS: AR was diagnosed in 21 (35%) athletes. 14 (42.4%) were orienteers and 7 (25.9%) were basketball players (P=0.144). Endoscopic findings and skin test positivity were also seen at higher percentages in orienteers with no significance. Training age (sport duration), total IgE levels and skin test positivity were significantly higher in rhinitic orieenters than non-rhinitic orieenters (P=0.046, P=0.0001, and P=0.004, respectively). CONCLUSIONS: Although adolescent orieenters had some higher allergic parameters than indoor athletes, they were not found more susceptible to AR. It seems that the frequency of AR increases with longer training age in orieentering sport. This study is the first report about AR in adolescent orienteers. Future researchs should more focus on comparing allergic conditions between outdoor and indoor sports.

[CYTOKINES SECRETION BY SPLENOCY-TES IN RESPONSE TO MICE F1 (C57BL/6XDBA/2) BEHAVIOR IN ENVIRONMENTS OF VARYING COMPLEXITY].

We study the dependence of the mitogen-induced cytokine secretion by splenocytes from the character of the behavior of F1 (C57BL/6XDBA/2) mice in environments with different degrees of spatial complexity: simple in the form of home box, enriched box and maze. Suppression of in-terleukins IL-2, IL-4, IL-6 and IL-10 expression, regardless of their structural and functional properties, was observed only in an enriched environment when aggressive and neurotic manifestations were increased. The opposite effect in the form of significant increase of the productions in all studied cytokines was observed in the case of the stereotypical goal-directed behavior in a maze. It was supposed that cytokines of the splenocytes are involved in the realization of highly 307 differentiated adaptive response of the organism due to the influence of social and cognitive factors, the expression of which depends on the specific physiological and biochemical systems.

Moderation of nicotine effects on covert orienting of attention tasks by poor placebo performance and cue validity.

INTRODUCTION AND RATIONALE: Given baseline-dependent effects of nicotine on other forms of attention, there is reason to believe that inconsistent findings for the effects of nicotine on attentional orienting may be partly due to individual differences in baseline (abstinence state) functioning. Individuals with low baseline attention may benefit more from nicotine replacement. METHOD: The effects of nicotine as a function of baseline performance (bottom, middle, and top third of mean reaction times during placebo) were assessed in 52 habitual abstinent smokers (26 females/26 males) utilizing an arrow-cued covert orienting of attention task. RESULTS: Compared to a placebo patch, a 14mg nicotine patch produced faster overall reaction times (RTs). In addition, individuals with slower RTs during the placebo condition benefitted more from nicotine on cued trials than did those who had shorter (faster) RTs during placebo. Nicotine also enhanced the validity effect (shorter RTs to validly vs. invalidly cued targets), but this nicotine benefit did not differ as a function of overall placebo-baseline performance. CONCLUSIONS: These findings support the view that nicotine enhances cued spatial attentional orienting in individuals who have slower RTs during placebo (nicotine-free) conditions; however, baseline-dependent effects may not generalize to all aspects of spatial attention. These findings are consistent with findings indicating that nicotine's effects vary as a function of task parameters rather than simple RT speeding or cognitive enhancement.

Pelvic orientation for total hip arthroplasty in lateral decubitus: can it be accurately measured?

INTRODUCTION: During total hip arthroplasty (THA), accurately predicting acetabular cup orientation remains a key challenge, in great part because of uncertainty about pelvic orientation. This pilot study aimed to develop and validate a technique to measure pelvic orientation; establish its accuracy in the location of anatomical landmarks and subsequently; investigate if limb movement during a simulated surgical procedure alters pelvic orientation. METHODS: The developed technique measured 3-D orientation of an isolated Sawbone pelvis, it was then implemented to measure pelvic orientation in lateral decubitus with post-THA patients (n = 20) using a motion capture system. RESULTS: Orientation of the isolated Sawbone pelvis was accurately measured, demonstrated by high correlations with angular data from a coordinate measurement machine; R-squared values close to 1 for all pelvic axes. When applied to volunteer subjects, largest movements occurred about the longitudinal pelvic axis; internal and external pelvic rotation. Rotations about the anteroposterior axis, which directly affect inclination angles, showed >75% of participants had movement within ±5° of neutral, 0°. CONCLUSIONS: The technique accurately measured orientation of the isolated bony pelvis. This was not the case in a simulated theatre environment. Soft tissue landmarks were difficult to palpate repeatedly. These findings have direct clinical relevance, landmark registration in lateral decubitus is a potential source of error, contributing here to large ranges in measured movement. Surgeons must be aware that present techniques using bony landmarks to reference pelvic orientation for cup implantation, both computer-based and mechanical, may not be sufficiently accurate.

Biological movement and the encoding of its motion and orientation.

Are you walking at me? Biological movement and the encoding of its motion and orientation. A person's motion conveys a wealth of information that ranges from the complex, such as intention or emotional state, to the simple, such as direction of locomotion. How we recognise and recover people's motion is addressed by models of biological motion processing. Single channel models propose that this occurs through the operation of form template neurons which respond to viewpoint dependent snapshots of posture. More controversially, a dual channel approach proposes a second stream containing motion template neurons sensitive to view dependent snapshots of biological movement's characteristic local velocity field. We used behavioural adaptation to look for the co-encoding of viewpoint and walker motion, a hallmark of motion template analysis. We show that opposite viewpoint aftereffects can simultaneously be induced for forwards and reversed walkers. This demonstrates that distinct populations of neurons encode forwards and reversed walking. To account for such aftereffects, these units must either be able to inhibit viewpoint-encoding neurons, or they must encode viewpoint directly. Whereas current single channel models would need extending to incorporate these characteristics, the idea that walker motion is encoded directly, such that viewpoint and motion are intrinsically interlinked, is a fundamental component of the dual channel model.