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Sample records for novelty locomotor response

  1. Locomotor response to novelty as a predictor of reactivity to aversive stimuli in the rat.

    PubMed

    White, David A; Kalinichev, Mikhail; Holtzman, Stephen G

    2007-05-29

    In an animal model for vulnerability to drug abuse, animals that exhibit greater motor activity in a novel environment (high responders; HR) are more sensitive to drugs of abuse and are more likely to self-administer these drugs compared to less reactive animals (low responders; LR). In the light of clinical evidence on comorbidity between drug abuse and mood disorders, we used this model to investigate whether individual differences in locomotor reactivity to novelty are related to anxiety- and depression-like responsiveness using male Sprague-Dawley rats. Animals were categorized as HR and LR based on motor responses to novelty during a 30-min session. Anxiety-like reactivity was then measured using the elevated plus-maze, the defensive withdrawal test and acoustic startle-induced ultrasonic vocalization test. Depression-like reactivity was measured by the forced swim test. HR rats showed less anxiety-like behavior in the elevated plus-maze and defensive withdrawal tests than LR, but the opposite was true in the acoustic startle-induced vocalization test. In response to a series of loud acoustic stimuli, HR rats were faster to begin vocalizing and did so for a longer duration compared to LR. There were only minor differences between LR and HR rats in the forced swim test. These data suggest that an HR/LR model can be used to study a link between vulnerability to drug abuse and anxiety-like reactivity. The exact nature of this link depends upon the model of anxiety used and may reflect the heterogeneous nature of anxiety-like reactivity in the rat. PMID:17383617

  2. Differential effects of social defeat in rats with high and low locomotor response to novelty.

    PubMed

    Calvo, N; Cecchi, M; Kabbaj, M; Watson, S J; Akil, H

    2011-06-01

    We compared the response to repeated social defeat in rats selected as high (HR) and low (LR) responders to novelty. In experiment 1, we investigated the behavioral and neuroendocrine effects of repeated social defeat in HR-LR rats. By the last defeat session, HR rats exhibited less passive-submissive behaviors than LR rats, and exhibited higher corticosterone secretion when recovering from defeat. Furthermore, in the forced swim test, while HR defeated rats spent more time immobile than their undefeated controls, LR rats' immobility was unaffected by defeat. In experiment 2, we compared the effects of repeated social defeat on body, adrenal, thymus, and spleen weights in HR-LR rats; moreover, we compared the effects of repeated social defeat on stress related molecules gene expression in these two groups of rats. Our results show that HR rats exhibited a decrease in thymus weight after repeated social defeat that was not present in LRs. Analyses of in situ hybridization results found HR-LR differences in 5-HT(2a) mRNA levels in the parietal cortex and 5-HT(1a) mRNA levels in the dorsal raphe. Moreover, LR rats had higher glucocorticoid receptor (GR) mRNA expression than HR rats in the dentate gyrus, and repeated social defeat decreased this expression in LR rats to HR levels. Finally, hippocampal mineralcorticoid receptor (MR)/GR ratio was reduced in HR rats only. Taken together, our results show a differential response to social defeat in HR-LR rats, and support the HR-LR model as a useful tool to investigate inter-individual differences in response to social stressors. PMID:21453756

  3. Capacity of novelty-induced locomotor activity and the hole-board test to predict sensitivity to the conditioned rewarding effects of cocaine.

    PubMed

    Arenas, M Carmen; Daza-Losada, Manuel; Vidal-Infer, Antonio; Aguilar, Maria A; Miñarro, José; Rodríguez-Arias, Marta

    2014-06-22

    Novelty-seeking in rodents, defined as enhanced specific exploration of novel situations, is considered to predict the response of animals to drugs of abuse and, thus, allow "drug-vulnerable" individuals to be identified. The main objective of this study was to assess the predictive ability of two well-known paradigms of the novelty-seeking trait - novelty-induced locomotor activity (which distinguishes High- and Low-Responder mice, depending on their motor activity) and the hole-board test (which determines High- and Low-Novelty Seeker mice depending on the number of head dips they perform) - to identify subjects that would subsequently be more sensitive to the conditioned rewarding effects of cocaine in a population of young adult (PND 56) and adolescent (PND 35) OF1 mice of both sexes. Conditioned place preference (CPP), a useful tool for evaluating the sensitivity of individuals to the incentive properties of addictive drugs, was induced with a sub-threshold dose of cocaine (1 mg/kg, i.p.). Our results showed that novelty-induced motor activity had a greater predictive capacity to identify "vulnerable-drug" individuals among young-adult mice (PND 56), while the hole-board test was more effective in adolescents (PND 35). High-NR young-adults, which presented higher motor activity in the first ten minutes of the test (novelty-reactivity), were 3.9 times more likely to develop cocaine-induced CPP than Low-NR young-adults. When total activity (1h) was evaluated (novelty-habituation), only High-R (novelty-non-habituating) young-adult male and Low-R (novelty-habituating) female mice produced a high conditioning score. However, only High-Novelty Seeker male and female adolescents and Low-Novelty Seeker female young-adult animals (according to the hole-board test), acquired cocaine-induced CPP. These findings should contribute to the development of screening methods for identifying at-risk human drug users and prevention strategies for those with specific

  4. Contrasting responses to novelty by wild and captive orangutans.

    PubMed

    Forss, Sofia I F; Schuppli, Caroline; Haiden, Dominique; Zweifel, Nicole; van Schaik, Carel P

    2015-10-01

    Several studies have suggested that wild primates tend to behave with caution toward novelty, whereas captive primates are thought to be less neophobic, more exploratory, and more innovative. However, few studies have systematically compared captive and wild individuals of the same species to document this "captivity effect" in greater detail. Here we report the responses of both wild and captive orangutans to the same novel items. Novel objects were presented to wild orangutans on multiple platforms placed in the canopy and equipped with motion-triggered video cameras. The same and different novel objects were also presented to orangutans in two different zoos. The results demonstrate extreme conservatism in both Bornean and Sumatran wild orangutans, who gradually approached the novel objects more closely as they became familiar, but avoided contact with them over many encounters spanning several months. Their zoo-living conspecifics, in contrast, showed an immediate neophilic response. Our results thus confirm the "captivity effect." To the various ecological explanations proposed before (reduced risk and increased time and energy balance for captive individuals relative to wild ones), we add the social information hypothesis, which claims that individuals confronted with novel items preferentially rely on social cues whenever possible. This caution toward novelty disappears when human caretakers become additional role models and can also be eroded when all experience with novelty is positive. PMID:26119509

  5. High Locomotor Reactivity to Novelty Is Associated with an Increased Propensity to Choose Saccharin Over Cocaine: New Insights into the Vulnerability to Addiction

    PubMed Central

    Vanhille, Nathalie; Belin-Rauscent, Aude; Mar, Adam C; Ducret, Eric; Belin, David

    2015-01-01

    Drug addiction is associated with a relative devaluation of natural or socially-valued reinforcers that are unable to divert addicts from seeking and consuming the drug. Before protracted drug exposure, most rats prefer natural rewards, such as saccharin, over cocaine. However, a subpopulation of animals prefer cocaine over natural rewards and are thought to be vulnerable to addiction. Specific behavioral traits have been associated with different dimensions of drug addiction. For example, anxiety predicts loss of control over drug intake whereas sensation seeking and sign-tracking are markers of a greater sensitivity to the rewarding properties of the drug. However, how these behavioral traits predict the disinterest for natural reinforcers remains unknown. In a population of rats, we identified sensation seekers (HR) on the basis of elevated novelty-induced locomotor reactivity, high anxious rats (HA) based on the propensity to avoid open arms in an elevated-plus maze and sign-trackers (ST) that are prone to approach, and interaction with, reward-associated stimuli. Rats were then tested on their preference for saccharin over cocaine in a discrete-trial choice procedure. We show that HR rats display a greater preference for saccharin over cocaine compared with ST and HA whereas the motivation for the drug was comparable between the three groups. The present data suggest that high locomotor reactivity to novelty, or sensation seeking, by predisposing to an increased choice toward non-drug rewards at early stages of drug use history, may prevent the establishment of chronic cocaine use. PMID:25120076

  6. High locomotor reactivity to novelty is associated with an increased propensity to choose saccharin over cocaine: new insights into the vulnerability to addiction.

    PubMed

    Vanhille, Nathalie; Belin-Rauscent, Aude; Mar, Adam C; Ducret, Eric; Belin, David

    2015-02-01

    Drug addiction is associated with a relative devaluation of natural or socially-valued reinforcers that are unable to divert addicts from seeking and consuming the drug. Before protracted drug exposure, most rats prefer natural rewards, such as saccharin, over cocaine. However, a subpopulation of animals prefer cocaine over natural rewards and are thought to be vulnerable to addiction. Specific behavioral traits have been associated with different dimensions of drug addiction. For example, anxiety predicts loss of control over drug intake whereas sensation seeking and sign-tracking are markers of a greater sensitivity to the rewarding properties of the drug. However, how these behavioral traits predict the disinterest for natural reinforcers remains unknown. In a population of rats, we identified sensation seekers (HR) on the basis of elevated novelty-induced locomotor reactivity, high anxious rats (HA) based on the propensity to avoid open arms in an elevated-plus maze and sign-trackers (ST) that are prone to approach, and interaction with, reward-associated stimuli. Rats were then tested on their preference for saccharin over cocaine in a discrete-trial choice procedure. We show that HR rats display a greater preference for saccharin over cocaine compared with ST and HA whereas the motivation for the drug was comparable between the three groups. The present data suggest that high locomotor reactivity to novelty, or sensation seeking, by predisposing to an increased choice toward non-drug rewards at early stages of drug use history, may prevent the establishment of chronic cocaine use. PMID:25120076

  7. Effects of inflammation on hippocampus and substantia nigra responses to novelty in healthy human participants.

    PubMed

    Harrison, Neil A; Cercignani, Mara; Voon, Valerie; Critchley, Hugo D

    2015-03-01

    Humans are naturally inquisitive. This tendency is adaptive, aiding identification of potentially valuable novel outcomes. The dopaminergic substantia nigra (SN) is implicated in the drive to explore novel stimuli and situations. However, infection and inflammation inhibit the motivation to seek out novelty. This likely serves to limit exposure to uncertain, potentially detrimental outcomes when metabolic resources are limited. Nevertheless, the neural mechanisms through which inflammation constrains novelty seeking are poorly understood. We therefore scanned 16 healthy participants (6 male, mean 27.2±7.3 years), using fMRI, once following experimental inflammation (intramuscular (i.m.) typhoid vaccination) and once after placebo (i.m. saline), with the aim of characterizing effects of inflammation on neural processing of novel and familiar place, and face stimuli. We specifically tested the effects of inflammation on the hypothesized roles of SN and hippocampus in novelty processing. Typhoid vaccination evoked a nearly threefold increase in circulating pro-inflammatory cytokine (interleukin-6) levels 3 h after injection, indicating induction of mild systemic inflammation. Enhanced hippocampal responses to novel (compared with familiar) stimuli were observed following both vaccine and placebo, consistent with intact central novelty detection. However, the normal bilateral reactivity of SN to stimulus novelty was significantly attenuated following inflammation. Correspondingly, inflammation also markedly impaired novelty-related functional coupling between the SN and hippocampus. These data extend previous findings of SN sensitivity to mild inflammation associated with changes in psychomotor responding, and suggest that inflammation-induced blunting of SN responses to hippocampal novelty signals may represent a plausible mechanism through which inflammation impairs motivational responses to novelty. PMID:25154706

  8. Effects of Inflammation on Hippocampus and Substantia Nigra Responses to Novelty in Healthy Human Participants

    PubMed Central

    Harrison, Neil A; Cercignani, Mara; Voon, Valerie; Critchley, Hugo D

    2015-01-01

    Humans are naturally inquisitive. This tendency is adaptive, aiding identification of potentially valuable novel outcomes. The dopaminergic substantia nigra (SN) is implicated in the drive to explore novel stimuli and situations. However, infection and inflammation inhibit the motivation to seek out novelty. This likely serves to limit exposure to uncertain, potentially detrimental outcomes when metabolic resources are limited. Nevertheless, the neural mechanisms through which inflammation constrains novelty seeking are poorly understood. We therefore scanned 16 healthy participants (6 male, mean 27.2±7.3 years), using fMRI, once following experimental inflammation (intramuscular (i.m.) typhoid vaccination) and once after placebo (i.m. saline), with the aim of characterizing effects of inflammation on neural processing of novel and familiar place, and face stimuli. We specifically tested the effects of inflammation on the hypothesized roles of SN and hippocampus in novelty processing. Typhoid vaccination evoked a nearly threefold increase in circulating pro-inflammatory cytokine (interleukin-6) levels 3 h after injection, indicating induction of mild systemic inflammation. Enhanced hippocampal responses to novel (compared with familiar) stimuli were observed following both vaccine and placebo, consistent with intact central novelty detection. However, the normal bilateral reactivity of SN to stimulus novelty was significantly attenuated following inflammation. Correspondingly, inflammation also markedly impaired novelty-related functional coupling between the SN and hippocampus. These data extend previous findings of SN sensitivity to mild inflammation associated with changes in psychomotor responding, and suggest that inflammation-induced blunting of SN responses to hippocampal novelty signals may represent a plausible mechanism through which inflammation impairs motivational responses to novelty. PMID:25154706

  9. Response to novelty: continuity versus discontinuity in the developmental course of intelligence.

    PubMed

    Berg, C A; Sternberg, R J

    1985-01-01

    In this article, we have reviewed research in diverse domains that has provided evidence for the assertion that intelligence can be construed, in part, as a response to novelty. We began by distinguishing two types of continuities, namely, the continuity in the fundamental nature of intelligence throughout development and the relative stability of individual differences in intellectual abilities at various ages. Current empirical and theoretical work has culminated in a proposition that the actual nature of intelligence is discontinuous, at least in the early years of life, and that individual differences in intellectual functions are unstable (Bayley, 1970; McCall, 1979a,b). Research on aspects of an infant's response to novelty and the relationship between this response and later intellectual functioning was examined and interpreted as reflective not only of one element of continuity in the actual nature of intelligence throughout development but also of a stable source of individual differences in intellectual development. Other literature reviewed suggested that the interest in and ability to deal with novelty remains an integral component of individual differences in intelligence throughout the life span. A framework for conceptualizing intelligence as, in part, the response to novelty was offered to provide some synthesis to the literature we have reviewed on the relationship between one's response to novelty and intelligence across the life span. This framework comprises two major aspects: a motivational aspect, referring to interest in, curiosity about, and preference for novelty, and an information-extraction aspect, referring to component processes that are involved in the acquisition of novel information. These two aspects of dealing with novelty were evident in the literature that was reviewed above. They seem integral to intellectual development. We are not alone in positing the importance of one's response to novelty as a major element of individual

  10. Happier, faster: Developmental changes in the effects of mood and novelty on responses.

    PubMed

    Schomaker, Judith; Rangel-Gomez, Mauricio; Meeter, Martijn

    2016-01-01

    Positive mood ameliorates several cognitive processes: It can enhance cognitive control, increase flexibility, and promote variety seeking in decision making. These effects of positive mood have been suggested to depend on frontostriatal dopamine, which is also associated with the detection of novelty. This suggests that positive mood could also affect novelty detection. In the present study, children and adults saw either a happy or a neutral movie to induce a positive or neutral mood. After that, they were shown novel and familiar images. On some trials a beep was presented over headphones either at the same time as the image or at a 200-ms stimulus onset asynchrony (SOA), and the task of the participant was to detect these auditory targets. Children were slower in responding than adults. Positive mood, however, speeded responses, especially in children, and induced facilitatory effects of novelty. These effects were consistent with increased arousal. Although effects of novelty were more consistent with an attentional response, in children who had watched a happy movie the novel images evoked a more liberal response criterion, suggestive of increased arousal. This suggests that mood and novelty may affect response behaviour stronger in children than in adults. PMID:25692224

  11. The role of oxytocin in familiarization-habituation responses to social novelty

    PubMed Central

    Tops, Mattie; Huffmeijer, Renske; Linting, Mariëlle; Grewen, Karen M.; Light, Kathleen C.; Koole, Sander L.; Bakermans-Kranenburg, Marian J.; van IJzendoorn, Marinus H.

    2013-01-01

    Stress or arousal responses to novel social contexts ease off when individuals get familiar with the social context. In the present study we investigated whether oxytocin is involved in this process of familiarization-habituation as oxytocin is known to increase trust and decrease anxiety. Fifty-nine healthy female subjects took part in the same experimental procedure in two sessions separated by 4 weeks. In the first (novelty) session state trust scores were significantly positively correlated with salivary oxytocin levels while in the second (familiarity) session state trust scores were significantly negatively correlated with salivary oxytocin levels. In a path model oxytocin was associated with increased trust in the novelty session and trust was associated with decreased oxytocin levels in the familiarity session. The results are consistent with the idea that oxytocin decreases stress-to-novelty responses by promoting familiarization to novel social contexts. PMID:24151482

  12. A strict response criterion yields a mirror effect in the novelty paradigm.

    PubMed

    Aberg, Carola S; Nilsson, Lars-Göran

    2003-12-01

    According to the novelty/encoding hypothesis (NEH; Tulving & Kroll, 1995), efficacy of encoding information into long-term memory depends on the movelty of the information. Recognition accuracy is higher for novel than for previously familiarized material. This novelty effect is not a mirror effect: the superiority of novel over familiar items is not found in the hit rates but only in the false-alarm rates. The main result in the present replication study was that novel hit rates were higher than familiar ones when the most confident responses were examined separately, and thus a mirror effect could be demonstrated for these data, for both the low- and the high-frequency words. Similarly, the word-frequency effect on hits was stronger when a stricter response criterion was applied. It was concluded that the novelty effect and the word-frequency effect are more similar to one another than has hitherto been thought. PMID:15030108

  13. Mice expressing markedly reduced striatal dopamine transporters exhibit increased locomotor activity, dopamine uptake turnover rate, and cocaine responsiveness.

    PubMed

    Rao, Anjali; Sorkin, Alexander; Zahniser, Nancy R

    2013-10-01

    Variations in the expression levels of the dopamine transporter (DAT) can influence responsiveness to psychostimulant drugs like cocaine. To better understand this relationship, we studied a new DAT-low expresser (DAT-LE) mouse model and performed behavioral and biochemical studies with it. Immunoblotting and [(3) H]WIN 35,428 binding analyses revealed that these mice express ∼35% of wildtype (WT) mouse striatal DAT levels. Compared to WT mice, DAT-LE mice were hyperactive in a novel open-field environment. Despite their higher basal locomotor activity, cocaine (10 or 20 mg/kg, i.p.) induced greater locomotor activation in DAT-LE mice than in WT mice. The maximal velocity (Vmax ) of DAT-mediated [(3) H]DA uptake into striatal synaptosomes was reduced by 46% in DAT-LE mice, as compared to WT. Overall, considering the reduced number of DAT binding sites (Bmax ) along with the reduced Vmax in DAT-LE mice, a 2-fold increase in DA uptake turnover rate (Vmax /Bmax ) was found, relative to WT mice. This suggests that neuroadaptive changes have occurred in the DAT-LE mice that would help to compensate for their low DAT numbers. Interestingly, these changes do not include a reduction in tyrosine hydroxylase levels, as was previously reported in DAT knockout homozygous and heterozygous animals. Further, these changes are not sufficient to prevent elevated novelty- and cocaine-induced locomotor activity. Hence, these mice represent a unique model for studying changes of in vivo DAT function and regulation that result from markedly reduced levels of DAT expression. PMID:23564231

  14. Making Sense of Infant Familiarity and Novelty Responses to Words at Lexical Onset

    PubMed Central

    DePaolis, Rory A.; Keren-Portnoy, Tamar; Vihman, Marilyn

    2016-01-01

    This study suggests that familiarity and novelty preferences in infant experimental tasks can in some instances be interpreted together as a single indicator of language advance. We provide evidence to support this idea based on our use of the auditory headturn preference paradigm to record responses to words likely to be either familiar or unfamiliar to infants. Fifty-nine 10-month-old infants were tested. The task elicited mixed preferences: familiarity (longer average looks to the words likely to be familiar to the infants), novelty (longer average looks to the words likely to be unfamiliar) and no-preference (similar-length of looks to both type of words). The infants who exhibited either a familiarity or a novelty response were more advanced on independent indices of phonetic advance than the infants who showed no preference. In addition, infants exhibiting novelty responses were more lexically advanced than either the infants who exhibited familiarity or those who showed no-preference. The results provide partial support for Hunter and Ames’ (1988) developmental model of attention in infancy and suggest caution when interpreting studies indexed to chronological age. PMID:27242624

  15. Finding and Not Finding Rat Perirhinal Neuronal Responses to Novelty.

    PubMed

    von Linstow Roloff, Eva; Muller, Robert U; Brown, Malcolm W

    2016-08-01

    There is much evidence that the perirhinal cortex of both rats and monkeys is important for judging the relative familiarity of visual stimuli. In monkeys many studies have found that a proportion of perirhinal neurons respond more to novel than familiar stimuli. There are fewer studies of perirhinal neuronal responses in rats, and those studies based on exploration of objects, have raised into question the encoding of stimulus familiarity by rat perirhinal neurons. For this reason, recordings of single neuronal activity were made from the perirhinal cortex of rats so as to compare responsiveness to novel and familiar stimuli in two different behavioral situations. The first situation was based upon that used in "paired viewing" experiments that have established rat perirhinal differences in immediate early gene expression for novel and familiar visual stimuli displayed on computer monitors. The second situation was similar to that used in the spontaneous object recognition test that has been widely used to establish the involvement of rat perirhinal cortex in familiarity discrimination. In the first condition 30 (25%) of 120 perirhinal neurons were visually responsive; of these responsive neurons 19 (63%) responded significantly differently to novel and familiar stimuli. In the second condition eight (53%) of 15 perirhinal neurons changed activity significantly in the vicinity of objects (had "object fields"); however, for none (0%) of these was there a significant activity change related to the familiarity of an object, an incidence significantly lower than for the first condition. Possible reasons for the difference are discussed. It is argued that the failure to find recognition-related neuronal responses while exploring objects is related to its detectability by the measures used, rather than the absence of all such signals in perirhinal cortex. Indeed, as shown by the results, such signals are found when a different methodology is used. © 2016 The Authors

  16. Finding and Not Finding Rat Perirhinal Neuronal Responses to Novelty

    PubMed Central

    Muller, Robert U.; Brown, Malcolm W.

    2016-01-01

    ABSTRACT There is much evidence that the perirhinal cortex of both rats and monkeys is important for judging the relative familiarity of visual stimuli. In monkeys many studies have found that a proportion of perirhinal neurons respond more to novel than familiar stimuli. There are fewer studies of perirhinal neuronal responses in rats, and those studies based on exploration of objects, have raised into question the encoding of stimulus familiarity by rat perirhinal neurons. For this reason, recordings of single neuronal activity were made from the perirhinal cortex of rats so as to compare responsiveness to novel and familiar stimuli in two different behavioral situations. The first situation was based upon that used in “paired viewing” experiments that have established rat perirhinal differences in immediate early gene expression for novel and familiar visual stimuli displayed on computer monitors. The second situation was similar to that used in the spontaneous object recognition test that has been widely used to establish the involvement of rat perirhinal cortex in familiarity discrimination. In the first condition 30 (25%) of 120 perirhinal neurons were visually responsive; of these responsive neurons 19 (63%) responded significantly differently to novel and familiar stimuli. In the second condition eight (53%) of 15 perirhinal neurons changed activity significantly in the vicinity of objects (had “object fields”); however, for none (0%) of these was there a significant activity change related to the familiarity of an object, an incidence significantly lower than for the first condition. Possible reasons for the difference are discussed. It is argued that the failure to find recognition‐related neuronal responses while exploring objects is related to its detectability by the measures used, rather than the absence of all such signals in perirhinal cortex. Indeed, as shown by the results, such signals are found when a different methodology is used.

  17. Single-trial decoding of auditory novelty responses facilitates the detection of residual consciousness.

    PubMed

    King, J R; Faugeras, F; Gramfort, A; Schurger, A; El Karoui, I; Sitt, J D; Rohaut, B; Wacongne, C; Labyt, E; Bekinschtein, T; Cohen, L; Naccache, L; Dehaene, S

    2013-12-01

    Detecting residual consciousness in unresponsive patients is a major clinical concern and a challenge for theoretical neuroscience. To tackle this issue, we recently designed a paradigm that dissociates two electro-encephalographic (EEG) responses to auditory novelty. Whereas a local change in pitch automatically elicits a mismatch negativity (MMN), a change in global sound sequence leads to a late P300b response. The latter component is thought to be present only when subjects consciously perceive the global novelty. Unfortunately, it can be difficult to detect because individual variability is high, especially in clinical recordings. Here, we show that multivariate pattern classifiers can extract subject-specific EEG patterns and predict single-trial local or global novelty responses. We first validate our method with 38 high-density EEG, MEG and intracranial EEG recordings. We empirically demonstrate that our approach circumvents the issues associated with multiple comparisons and individual variability while improving the statistics. Moreover, we confirm in control subjects that local responses are robust to distraction whereas global responses depend on attention. We then investigate 104 vegetative state (VS), minimally conscious state (MCS) and conscious state (CS) patients recorded with high-density EEG. For the local response, the proportion of significant decoding scores (M=60%) does not vary with the state of consciousness. By contrast, for the global response, only 14% of the VS patients' EEG recordings presented a significant effect, compared to 31% in MCS patients' and 52% in CS patients'. In conclusion, single-trial multivariate decoding of novelty responses provides valuable information in non-communicating patients and paves the way towards real-time monitoring of the state of consciousness. PMID:23859924

  18. Information theory, novelty and hippocampal responses: unpredicted or unpredictable?

    PubMed

    Strange, Bryan A; Duggins, Andrew; Penny, William; Dolan, Raymond J; Friston, Karl J

    2005-04-01

    Shannon's information theory provides a principled framework for the quantitative analysis of brain responses during the encoding and representation of event streams. In particular, entropy measures the expected uncertainty of events in a given context. This contextual uncertainty or unpredictability may, itself, be important for balancing [bottom-up] sensory information and [top-down] prior expectations during perceptual synthesis. Using event-related functional magnetic resonance imaging (fMRI), we found that the anterior hippocampus is sensitive to the entropy of a visual stimulus stream. In contrast, activity in an extensive bilateral cortico-thalamic network was dictated by the surprise or information associated with each particular stimulus. In short, we show that the probabilistic structure or context in which events occur is an important predictor of hippocampal activity. PMID:15896570

  19. The pupillary response discriminates between subjective and objective familiarity and novelty

    PubMed Central

    Montaldi, Daniela

    2015-01-01

    Abstract The pupil response discriminates between old and new stimuli, with old stimuli characterized by larger pupil dilation patterns than new stimuli. We sought to explore the cause of the pupil old/new effect and discount the effect of targetness, effort, recollection retrieval, and complexity of the recognition decision. Two experiments are reported in which the pupil response and the eye fixation patterns were measured, while participants identified novel and familiar object stimuli, in two separate tasks, emphasizing either novelty or familiarity detection. In Experiment 1, familiarity and novelty decisions were taken using a rating scale, while in Experiment 2 a simpler yes/no decision was used. In both experiments, we found that detection of target familiar stimuli resulted in greater pupil dilation than the detection of target novel stimuli, while the duration of the first fixation discriminated between familiar and novel stimuli as early as within 320 ms after stimulus onset. Importantly, the pupil response distinguished between the objective (during an earlier temporal component) and the subjective (during a later temporal component) status of the stimulus for misses and false alarms. In the light of previous findings, we suggest that the pupil and fixation old/new effects reflect the distinct neural and cognitive mechanisms involved in the familiarity and novelty decisions. The findings also have important implications for the use of pupil dilation and eye movement patterns to explore explicit and implicit memory processes. PMID:26174940

  20. Effects of methylphenidate on responses to novelty in a teleost fish (Poecilia reticulata).

    PubMed

    De Serrano, Alex R; Fong, Charmaine; Rodd, F Helen

    2016-04-01

    Novelty seeking, the willingness to explore novel stimuli, can have important fitness consequences. The neurotransmitter dopamine has been linked to this behavior in studies on lab animals including rodents and fish; however, few studies have investigated this association in individuals from natural populations. Trinidadian guppies (Poecilia reticulata) show variation in willingness to explore novel objects and environments, and females tend to show a preference for novel males. In this study, we asked whether we could enhance interest in several types of novel stimuli in lab-reared, female Trinidadian guppies by administering methylphenidate hydrochloride, a stimulant known to increase dopamine levels. We scored their responses to three different types of novelty: novel environments, objects, and males. Treated females showed enhanced exploratory behavior: they traversed relatively more inner squares of the novel environment (open-field test); they spent more time inspecting a novel object; and they showed greater interest in the second male guppy to which they were exposed than control fish. We also found a positive association between our metrics of exploration in the open field and novel object tests. Our other assays suggest that these differences were not the result of increased activity or reduced levels of stress. Therefore, our results suggest that dopamine plays a role in the responsiveness of guppies to novelty; this opens the door to studies of behavioral mechanisms in natural populations. PMID:26792109

  1. Ghrelin Influences Novelty Seeking Behavior in Rodents and Men

    PubMed Central

    Hansson, Caroline; Shirazi, Rozita H.; Näslund, Jakob; Vogel, Heike; Neuber, Corinna; Holm, Göran; Anckarsäter, Henrik; Dickson, Suzanne L.; Eriksson, Elias; Skibicka, Karolina P.

    2012-01-01

    Recent discoveries indicate an important role for ghrelin in drug and alcohol reward and an ability of ghrelin to regulate mesolimbic dopamine activity. The role of dopamine in novelty seeking, and the association between this trait and drug and alcohol abuse, led us to hypothesize that ghrelin may influence novelty seeking behavior. To test this possibility we applied several complementary rodent models of novelty seeking behavior, i.e. inescapable novelty-induced locomotor activity (NILA), novelty-induced place preference and novel object exploration, in rats subjected to acute ghrelin receptor (growth hormone secretagogue receptor; GHSR) stimulation or blockade. Furthermore we assessed the possible association between polymorphisms in the genes encoding ghrelin and GHSR and novelty seeking behavior in humans. The rodent studies indicate an important role for ghrelin in a wide range of novelty seeking behaviors. Ghrelin-injected rats exhibited a higher preference for a novel environment and increased novel object exploration. Conversely, those with GHSR blockade drastically reduced their preference for a novel environment and displayed decreased NILA. Importantly, the mesolimbic ventral tegmental area selective GHSR blockade was sufficient to reduce the NILA response indicating that the mesolimbic GHSRs might play an important role in the observed novelty responses. Moreover, in untreated animals, a striking positive correlation between NILA and sucrose reward behavior was detected. Two GHSR single nucleotide polymorphisms (SNPs), rs2948694 and rs495225, were significantly associated with the personality trait novelty seeking, as assessed using the Temperament and Character Inventory (TCI), in human subjects. This study provides the first evidence for a role of ghrelin in novelty seeking behavior in animals and humans, and also points to an association between food reward and novelty seeking in rodents. PMID:23227170

  2. Interaction between 5-HT1B receptors and nitric oxide in zebrafish responses to novelty.

    PubMed

    Maximino, Caio; Lima, Monica Gomes; Batista, Evander de Jesus Oliveira; Oliveira, Karen Renata Herculano Matos; Herculano, Anderson Manoel

    2015-02-19

    Nitric oxide (NO) and serotonin (5-HT) interact at the molecular and systems levels to control behavioral variables, including agression, fear, and reactions to novelty. In zebrafish, the 5-HT1B receptor has been implicated in anxiety and reactions to novelty, while the 5-HT1A receptor is associated with anxiety-like behavior; this role of the 5-HT1A receptor is mediated by NO. This work investigated whether NO also participates in the mediation of novelty responses by the 5-HT1B receptor. The 5-HT1B receptor inverse agonist SB 224,289 decreased bottom-dwelling and erratic swimming in zebrafish; the effects on bottom-dwelling, but not on erratic swimming, were blocked by pre-treatment with the nitric oxide synthase inhibitor L-NAME. These effects underline a novel mechanism by which 5-HT controls zebrafish reactivity to novel environments, with implications for the study of neotic reactions, exploratory behavior, and anxiety-like states. PMID:25545556

  3. Novelty and emotion: Pupillary and cortical responses during viewing of natural scenes.

    PubMed

    Ferrari, Vera; De Cesarei, Andrea; Mastria, Serena; Lugli, Luisa; Baroni, Giulia; Nicoletti, Roberto; Codispoti, Maurizio

    2016-01-01

    Given the remarkable similarities in the antecedent conditions-stimulus motivational relevance and novelty (i.e., probability of occurrence)-that elicit amplitude modulation of the late positive potential (LPP) and the pupillary dilation response, the present study examines whether these two indexes of orienting response reflect common processes that are responsible for modulatory patterns in motivationally relevant contexts. In the present study, the LPP and the pupillary dilation response were co-registered in a free-picture viewing context in which stimulus novelty was manipulated through repeated presentation of the same picture exemplar. More specifically, pictures depicting both emotional and neutral contents could be novel, that is never seen before in the course of the study, or repeated 4-8 times in a row (i.e., massed repetition). Results showed that, despite massed repetitions, the late positive potential amplitude continued to be highly modulated by picture content, whereas affective modulation of pupil dilation decreased with picture repetition. These findings indicate that, although the LPP and pupil dilation are similarly affected by motivational relevance during the viewing of novel pictures, they differ when pictures are highly familiar, possibly reflecting different functional meanings in the context of the orienting response. PMID:26631353

  4. Dissociating intentional learning from relative novelty responses in the medial temporal lobe.

    PubMed

    Strange, Bryan A; Hurlemann, René; Duggins, Andrew; Heinze, Hans-Jochen; Dolan, Raymond J

    2005-03-01

    The establishment of a role for medial temporal lobe (MTL) structures in episodic memory has led to an investigative focus on the specific contributions and interactions between constituent MTL regions, including the hippocampus and surrounding medial temporal cortices. By dissociating an intentional stimulus-category learning condition from a passive viewing condition, we demonstrate, using fMRI, that novelty- and familiarity-driven responses in human anterior and posterior hippocampus, respectively, only occur during intentional learning. With increasing familiarity of stimulus-category associations, there is a shift in neuronal responses from anterior to posterior hippocampal regions. This anterior/posterior response gradient may reflect a weighting of functional hippocampal architecture related to encoding of novel and retrieval of familiar information. By contrast, perirhinal cortex is engaged by novel stimuli irrespective of task, highlighting this region as a component of a generic familiarity discrimination system. By introducing distinct stimulus types, we further demonstrate that these MTL responses are independent of stimulus complexity. Different patterns of activity for intentional learning vs. passive viewing indicate that intentional encoding/retrieval of stimulus-category associations and automatic novelty/familiarity assessment of stimuli are processed in anatomically dissociable neuronal ensembles within the MTL memory system. PMID:15734343

  5. Relations between peripheral and brain serotonin measures and behavioural responses in a novelty test in pigs.

    PubMed

    Ursinus, Winanda W; Bolhuis, J Elizabeth; Zonderland, Johan J; Rodenburg, T Bas; de Souza, Adriana S; Koopmanschap, Rudie E; Kemp, Bas; Korte-Bouws, Gerdien A H; Korte, S Mechiel; van Reenen, Cornelis G

    2013-06-13

    Pigs differ in their behavioural responses towards environmental challenges. Individual variation in maladaptive responses such as tail biting, may partly originate from underlying biological characteristics related to (emotional) reactivity to challenges and serotonergic system functioning. Assessing relations between behavioural responses and brain and blood serotonin parameters may help in understanding susceptibility to the development of maladaptive responses. The objective of the current study was, therefore, to assess the relationship between the pigs' serotonergic parameters measured in both blood and brain, and the behaviour of pigs during a novelty test. Pigs (n=31) were subjected to a novelty test at 11weeks of age, consisting of 5-min novel environment exposure after which a novel object (a bucket) was introduced for 5min. Whole blood serotonin, platelet serotonin level, and platelet serotonin uptake were determined at 13weeks of age. Levels of serotonin, its metabolite and serotonin turnover were determined at 19weeks of age in the frontal cortex, hypothalamus and hippocampus. The behaviour of the pigs was different during exposure to a novel object compared to the novel environment only, with more fear-related behaviours exhibited during novel object exposure. Platelet serotonin level and brain serotonergic parameters in the hippocampus were interrelated. Notably, the time spent exploring the test arena was significantly correlated with both platelet serotonin level and right hippocampal serotonin activity (turnover and concentration). In conclusion, the existence of an underlying biological trait - possibly fearfulness - may be involved in the pig's behavioural responses toward environmental challenges, and this is also reflected in serotonergic parameters. PMID:23685231

  6. Locomotor training modifies soleus monosynaptic motoneuron responses in human spinal cord injury

    PubMed Central

    Smith, Andrew C.; Rymer, William Zev

    2015-01-01

    The objective of this study was to assess changes in monosynaptic motoneuron responses to stimulation of Ia afferents after locomotor training in individuals with chronic spinal cord injury (SCI). We hypothesized that locomotor training modifies the amplitude of the soleus monosynaptic motoneuron responses in a body position-dependent manner. Fifteen individuals with chronic clinical motor complete or incomplete SCI received an average of 45 locomotor training sessions. The soleus H-reflex and M-wave recruitment curves were assembled using data collected in both the right and left legs, with subjects seated and standing, before and after training. The soleus H-reflexes and M-waves, measured as peak-to-peak amplitudes, were normalized to the maximal M-wave (Mmax). Stimulation intensities were normalized to 50 % Mmax stimulus intensity. A sigmoid function was also fitted to the normalized soleus H-reflexes on the ascending limb of the recruitment curve. After training, soleus H-reflex excitability was increased in both legs in AIS C subjects, and remained unchanged in AIS A-B and AIS D subjects during standing. When subjects were seated, soleus H-reflex excitability was decreased after training in many AIS C and D subjects. Changes in reflex excitability coincided with changes in stimulation intensities at H-threshold, 50 % maximal H-reflex, and at maximal H-reflex, while an interaction between leg side and AIS scale for the H-reflex slope was also found. Adaptations of the intrinsic properties of soleus motoneurons and Ia afferents, the excitability profile of the soleus motoneuron pool, oligosynaptic inputs, and corticospinal inputs may all contribute to these changes. The findings of this study demonstrate that locomotor training impacts the amplitude of the monosynaptic motoneuron responses based on the demands of the motor task in people with chronic SCI. PMID:25205562

  7. New insights on amygdala: Basomedial amygdala regulates the physiological response to social novelty.

    PubMed

    Mesquita, Laura Tavares; Abreu, Aline Rezende; de Abreu, Alessandra Rezende; de Souza, Aline Arlindo; de Noronha, Sylvana Rendeiro; Silva, Fernanda Cacilda; Campos, Glenda Siqueira Viggiano; Chianca, Deoclecio Alves; de Menezes, Rodrigo Cunha

    2016-08-25

    The amygdala has been associated with a variety of functions linked to physiological, behavioral and endocrine responses during emotional situations. This brain region is comprised of multiple sub-nuclei. These sub-nuclei belong to the same structure, but may be involved in different functions, thereby making the study of each sub-nuclei important. Yet, the involvement of the basomedial amygdala (BMA) in the regulation of emotional states has yet to be defined. Therefore, the aim of our study was to investigate the regulatory role of the BMA on the responses evoked during a social novelty model and whether the regulatory role depended on an interaction with the dorsomedial hypothalamus (DMH). Our results showed that the chemical inhibition of the BMA by the microinjection of muscimol (γ-aminobutyric acid (GABAA) agonist) promoted increases in mean arterial pressure (MAP) and heart rate (HR), whereas the chemical inhibition of regions near the BMA did not induce such cardiovascular changes. In contrast, the BMA chemical activation by the bilateral microinjection of bicuculline methiodide (BMI; GABAA antagonist), blocked the increases in MAP and HR observed when an intruder rat was suddenly introduced into the cage of a resident rat, and confined to the small cage for 15min. Additionally, the increase in HR and MAP induced by BMA inhibition were eliminated by DMH chemical inhibition. Thus, our data reveal that the BMA is under continuous GABAergic influence, and that its hyperactivation can reduce the physiological response induced by a social novelty condition, possibly by inhibiting DMH neurons. PMID:27261213

  8. Decreased entropy modulation of EEG response to novelty and relevance in schizophrenia during a P300 task.

    PubMed

    Bachiller, Alejandro; Lubeiro, Alba; Díez, Álvaro; Suazo, Vanessa; Domínguez, Cristina; Blanco, José A; Ayuso, Marta; Hornero, Roberto; Poza, Jesús; Molina, Vicente

    2015-09-01

    The analysis of the interaction between novelty and relevance may be of interest to test the aberrant salience hypothesis of schizophrenia (SCH). In comparison with other neuroimaging techniques, such as functional magnetic resonance imaging, electroencephalography (EEG) provides high temporal resolution. Therefore, EEG is useful to analyze transient dynamics in neural activity, even in the range of milliseconds. In this study, EEG activity from 31 patients with SCH and 38 controls was analyzed using Shannon spectral entropy (SE) and median frequency (MF). The aim of the study was to quantify differences between distractor (i.e., novelty) and target (i.e., novelty and relevance) tones in an auditory oddball paradigm. Healthy controls displayed a larger SE decrease in response to target stimulus than in response to distractor tones. SE decrease was accompanied by a significant and widespread reduction of MF (i.e., a significant slowing of EEG activity). In comparison with controls, patients showed a significant reduction of changes in SE in response to both target and distractor tones. These differences were also observed in patients that only received a minimal treatment prior to EEG recording. Furthermore, significant changes in SE were inversely correlated to positive and total symptoms severity for SCH patients. Our findings support the notion that SCH is associated with a reduced response to both novelty and relevance during an auditory P300 task. PMID:25164969

  9. Localization of the event-related potential novelty response as defined by principal components analysis.

    PubMed

    Dien, Joseph; Spencer, Kevin M; Donchin, Emanuel

    2003-10-01

    Recent research indicates that novel stimuli elicit at least two distinct components, the Novelty P3 and the P300. The P300 is thought to be elicited when a context updating mechanism is activated by a wide class of deviant events. The functional significance of the Novelty P3 is uncertain. Identification of the generator sources of the two components could provide additional information about their functional significance. Previous localization efforts have yielded conflicting results. The present report demonstrates that the use of principal components analysis (PCA) results in better convergence with knowledge about functional neuroanatomy than did previous localization efforts. The results are also more convincing than that obtained by two alternative methods, MUSIC-RAP and the Minimum Norm. Source modeling on 129-channel data with BESA and BrainVoyager suggests the P300 has sources in the temporal-parietal junction whereas the Novelty P3 has sources in the anterior cingulate. PMID:14561451

  10. Adaptability: How Students' Responses to Uncertainty and Novelty Predict Their Academic and Non-Academic Outcomes

    ERIC Educational Resources Information Center

    Martin, Andrew J.; Nejad, Harry G.; Colmar, Susan; Liem, Gregory Arief D.

    2013-01-01

    Adaptability is defined as appropriate cognitive, behavioral, and/or affective adjustment in the face of uncertainty and novelty. Building on prior measurement work demonstrating the psychometric properties of an adaptability construct, the present study investigates dispositional predictors (personality, implicit theories) of adaptability, and…

  11. Prediction of individual differences in fear response by novelty seeking, and disruption of contextual fear memory reconsolidation by ketamine.

    PubMed

    Duclot, Florian; Perez-Taboada, Iara; Wright, Katherine N; Kabbaj, Mohamed

    2016-10-01

    Only a portion of the population exposed to trauma will develop persistent emotional alterations characteristic of posttraumatic stress disorder (PTSD), which illustrates the necessity for identifying vulnerability factors and novel pharmacotherapeutic alternatives. Interestingly, clinical evidence suggests that novelty seeking is a good predictor for vulnerability to the development of excessive and persistent fear. Here, we first tested this hypothesis by analyzing contextual and cued fear responses of rats selected for their high (high responders, HR) or low (low responders, LR) exploration of a novel environment, indicator of novelty seeking. While HR and LR rats exhibited similar sensitivity to the shock and cued fear memory retention, fewer extinction sessions were required in HR than LR animals to reach extinction, indicating faster contextual and cued memory extinction. In a second part, we found an effective disruption of contextual fear reconsolidation by the N-methyl-d-aspartate receptor antagonist ketamine, associated with a down-regulation of early growth response 1 (Egr1) in the hippocampal CA1 area, and up-regulation of brain-derived neurotrophic factor (Bdnf) mRNA levels in the prelimbic and infralimbic cortices. Altogether, these data demonstrate a link between novelty seeking and conditioned fear extinction, and highlight a promising novel role of ketamine in affecting established fear memory. PMID:27343386

  12. Contagious risk taking: social information and context influence wild jackdaws' responses to novelty and risk.

    PubMed

    Greggor, Alison L; McIvor, Guillam E; Clayton, Nicola S; Thornton, Alex

    2016-01-01

    Although wild animals increasingly encounter human-produced food and objects, it is unknown how they learn to discriminate beneficial from dangerous novelty. Since social learning allows animals to capitalize on the risk-taking of others, and avoid endangering themselves, social learning should be used around novel and unpredictable stimuli. However, it is unclear whether animals use social cues equally around all types of novelty and at all times of year. We assessed whether wild, individually marked jackdaws-a highly neophobic, yet adaptable species-are equally influenced by social cues to consume novel, palatable foods and to approach a startling object. We conducted these tests across two seasons, and found that in both seasons observers were more likely to consume novel foods after seeing a demonstrator do so. In contrast, observers only followed the demonstrator in foraging next to the object during breeding season. Throughout the year more birds were wary of consuming novel foods than wary of approaching the object, potentially leading to jackdaws' greater reliance on social information about food. Jackdaws' dynamic social cue usage demonstrates the importance of context in predicting how social information is used around novelty, and potentially indicates the conditions that facilitate animals' adjustment to anthropogenic disturbance. PMID:27282438

  13. Contagious risk taking: social information and context influence wild jackdaws’ responses to novelty and risk

    PubMed Central

    Greggor, Alison L.; McIvor, Guillam E.; Clayton, Nicola S.; Thornton, Alex

    2016-01-01

    Although wild animals increasingly encounter human-produced food and objects, it is unknown how they learn to discriminate beneficial from dangerous novelty. Since social learning allows animals to capitalize on the risk-taking of others, and avoid endangering themselves, social learning should be used around novel and unpredictable stimuli. However, it is unclear whether animals use social cues equally around all types of novelty and at all times of year. We assessed whether wild, individually marked jackdaws—a highly neophobic, yet adaptable species—are equally influenced by social cues to consume novel, palatable foods and to approach a startling object. We conducted these tests across two seasons, and found that in both seasons observers were more likely to consume novel foods after seeing a demonstrator do so. In contrast, observers only followed the demonstrator in foraging next to the object during breeding season. Throughout the year more birds were wary of consuming novel foods than wary of approaching the object, potentially leading to jackdaws’ greater reliance on social information about food. Jackdaws’ dynamic social cue usage demonstrates the importance of context in predicting how social information is used around novelty, and potentially indicates the conditions that facilitate animals’ adjustment to anthropogenic disturbance. PMID:27282438

  14. Conditioned place preference and locomotor activity in response to methylphenidate, amphetamine and cocaine in mice lacking dopamine D4 receptors

    SciTech Connect

    Thanos, P.K.; Thanos, P.K.; Bermeo, C.; Rubinstein, M.; Suchland, K.L.; Wang, G.-J.; Grandy, D.K.; Volkow, N.D.

    2010-05-01

    Methylphenidate (MP) and amphetamine (AMPH) are the most frequently prescribed medications for the treatment of attention-deficit/hyperactivity disorder (ADHD). Both drugs are believed to derive their therapeutic benefit by virtue of their dopamine (DA)-enhancing effects, yet an explanation for the observation that some patients with ADHD respond well to one medication but not to the other remains elusive. The dopaminergic effects of MP and AMPH are also thought to underlie their reinforcing properties and ultimately their abuse. Polymorphisms in the human gene that codes for the DA D4 receptor (D4R) have been repeatedly associated with ADHD and may correlate with the therapeutic as well as the reinforcing effects of responses to these psychostimulant medications. Conditioned place preference (CPP) for MP, AMPH and cocaine were evaluated in wild-type (WT) mice and their genetically engineered littermates, congenic on the C57Bl/6J background, that completely lack D4Rs (knockout or KO). In addition, the locomotor activity in these mice during the conditioning phase of CPP was tested in the CPP chambers. D4 receptor KO and WT mice showed CPP and increased locomotor activity in response to each of the three psychostimulants tested. D4R differentially modulates the CPP responses to MP, AMPH and cocaine. While the D4R genotype affected CPP responses to MP (high dose only) and AMPH (low dose only) it had no effects on cocaine. Inasmuch as CPP is considered an indicator of sensitivity to reinforcing responses to drugs these data suggest a significant but limited role of D4Rs in modulating conditioning responses to MP and AMPH. In the locomotor test, D4 receptor KO mice displayed attenuated increases in AMPH-induced locomotor activity whereas responses to cocaine and MP did not differ. These results suggest distinct mechanisms for D4 receptor modulation of the reinforcing (perhaps via attenuating dopaminergic signalling) and locomotor properties of these stimulant drugs

  15. Does the age-related "anterior shift" of the P3 reflect an inability to habituate the novelty response?

    PubMed Central

    Alperin, Brittany R.; Mott, Katherine K.; Holcomb, Phillip J.; Daffner, Kirk R.

    2014-01-01

    Old adults often generate larger anterior neural responses than young adults when carrying out task requirements. A common finding in the ERP literature is an "anterior shift" of the P3b to targets. Utilizing principal component analysis (PCA), we recently demonstrated that rather than the P3b moving anteriorly, old adults generate a large P3a that temporally overlaps with their P3b. A dominant hypothesis for the age-related increase in anterior P3 is the failure to habituate the brain’s novelty response to rare targets. We tested this hypothesis in young and old adults by comparing the amplitude of the PCA factor representing P3a to targets presented in the first versus last of eight blocks of a visual oddball task. If, unlike young adults, old adults are unable to habituate a novelty response, one would expect 1) the P3a amplitude to decrease between the first and last blocks for young, but not old subjects and 2) the difference in P3a amplitude between young and old subjects to be greater in the last than the first block. Our results indicate the amplitude of the P3a was larger in old adults than young adults. However, this effect was not modulated by block. These findings argue against the hypothesis that an age-related increase in the P3a to targets reflects an inability of old subjects to habituate a novelty response. An alternative hypothesis is that the augmented P3a indexes the increased utilization of frontal executive functions to provide compensatory scaffolding to carry out a task. PMID:24905171

  16. Novelty's effect on memory encoding.

    PubMed

    Rangel-Gomez, Mauricio; Janenaite, Sigita; Meeter, Martijn

    2015-07-01

    It is often thought that novelty benefits memory formation. However, support for this idea mostly comes from paradigms that are open to alternative explanations. In the present study we manipulated novelty in a word-learning task through task-irrelevant background images. These background images were either standard (presented repeatedly), or novel (presented only once). Two types of background images were used: Landscape pictures and fractals. EEG was also recorded during encoding. Contrary to the idea that novelty aids memory formation, memory performance was not affected by the novelty of the background. In the evoked response potentials, we found evidence of distracting effects of novelty: both the N1 and P3b components were smaller to words studied with novel backgrounds, and the amplitude of the N2b component correlated negatively with subsequent retrieval. We conclude that although evidence from other studies does suggest benefits on a longer time scale, novelty has no instantaneous benefits for learning. PMID:26005196

  17. Dose-dependent changes in the locomotor responses to methamphetamine in BALB/c mice: Low doses induce hypolocomotion

    PubMed Central

    Singh, Rana A. K.; Kosten, Therese A.; Kinsey, Berma M.; Shen, Xiaoyun; Lopez, Angel Y.; Kosten, Thomas R.; Orson, Frank M.

    2012-01-01

    The overall goal of the present study was to determine the effects of different doses of (+)-methamphetamine (meth) on locomotor activity of Balb/C mice. Four experiments were designed to test a wide range of meth doses in BALB/c female mice. In Experiment 1, we examined locomotor activity induced by an acute administration of low doses of meth (0.01 and 0.03 mg/kg) in a 90-min session. Experiment 2 was conducted to test higher meth doses (0.3 – 10 mg/kg). In Experiment 3, separate sets of mice were pre-treated with various meth doses once or twice (one injection/week) prior to a locomotor challenge with a low meth dose. Finally, in Experiment 4, we tested whether locomotor activation would be affected by pretreatment with a low or moderate dose of meth one month prior to the low meth dose challenge. Results show that low doses of meth induce hypolocomotion whereas moderate to high doses induce hyperlocomotion. Prior exposure to either one moderate or high dose of meth or to two, low doses of meth attenuated the hypolocomotor effect of a low meth dose one week later. This effect was also attenuated in mice tested one month after administration of a moderate meth dose. These results show that low and high doses of meth can have opposing effects on locomotor activity. Further, prior exposure to the drug leads to tolerance, rather than sensitization, of the hypolocomotor response to low meth doses. PMID:23010423

  18. Infants' ERP Responses to Novel and Familiar Stimuli Change over Time: Implications for Novelty Detection and Memory

    ERIC Educational Resources Information Center

    Wiebe, Sandra A.; Cheatham, Carol L.; Lukowski, Angela F.; Haight, Jennifer C.; Muehleck, Abigail J.; Bauer, Patricia J.

    2006-01-01

    Detection of novelty is an important cognitive ability early in development, when infants must learn a great deal about their world. Work with adults has identified networks of brain areas involved in novelty detection; this study investigated electro-physiological correlates of detection of novelty and recognition of familiarity in 9-month-old…

  19. Comprehensive behavioral analysis of RNG105 (Caprin1) heterozygous mice: Reduced social interaction and attenuated response to novelty.

    PubMed

    Ohashi, Rie; Takao, Keizo; Miyakawa, Tsuyoshi; Shiina, Nobuyuki

    2016-01-01

    RNG105 (also known as Caprin1) is a major RNA-binding protein in neuronal RNA granules, and is responsible for mRNA transport to dendrites and neuronal network formation. A recent study reported that a heterozygous mutation in the Rng105 gene was found in an autism spectrum disorder (ASD) patient, but it remains unclear whether there is a causal relation between RNG105 deficiency and ASD. Here, we subjected Rng105(+/-) mice to a comprehensive behavioral test battery, and revealed the influence of RNG105 deficiency on mouse behavior. Rng105(+/-) mice exhibited a reduced sociality in a home cage and a weak preference for social novelty. Consistently, the Rng105(+/-) mice also showed a weak preference for novel objects and novel place patterns. Furthermore, although the Rng105(+/-) mice exhibited normal memory acquisition, they tended to have relative difficulty in reversal learning in the spatial reference tasks. These findings suggest that the RNG105 heterozygous knockout leads to a reduction in sociality, response to novelty and flexibility in learning, which are implicated in ASD-like behavior. PMID:26865403

  20. Comprehensive behavioral analysis of RNG105 (Caprin1) heterozygous mice: Reduced social interaction and attenuated response to novelty

    PubMed Central

    Ohashi, Rie; Takao, Keizo; Miyakawa, Tsuyoshi; Shiina, Nobuyuki

    2016-01-01

    RNG105 (also known as Caprin1) is a major RNA-binding protein in neuronal RNA granules, and is responsible for mRNA transport to dendrites and neuronal network formation. A recent study reported that a heterozygous mutation in the Rng105 gene was found in an autism spectrum disorder (ASD) patient, but it remains unclear whether there is a causal relation between RNG105 deficiency and ASD. Here, we subjected Rng105+/− mice to a comprehensive behavioral test battery, and revealed the influence of RNG105 deficiency on mouse behavior. Rng105+/− mice exhibited a reduced sociality in a home cage and a weak preference for social novelty. Consistently, the Rng105+/− mice also showed a weak preference for novel objects and novel place patterns. Furthermore, although the Rng105+/− mice exhibited normal memory acquisition, they tended to have relative difficulty in reversal learning in the spatial reference tasks. These findings suggest that the RNG105 heterozygous knockout leads to a reduction in sociality, response to novelty and flexibility in learning, which are implicated in ASD-like behavior. PMID:26865403

  1. Hemodynamic Response of the Supplementary Motor Area during Locomotor Tasks with Upright versus Horizontal Postures in Humans.

    PubMed

    Yozu, Arito; Obayashi, Shigeru; Nakajima, Katsumi; Hara, Yukihiro

    2016-01-01

    To understand cortical mechanisms related to truncal posture control during human locomotion, we investigated hemodynamic responses in the supplementary motor area (SMA) with quadrupedal and bipedal gaits using functional near-infrared spectroscopy in 10 healthy adults. The subjects performed three locomotor tasks where the degree of postural instability varied biomechanically, namely, hand-knee quadrupedal crawling (HKQuad task), upright quadrupedalism using bilateral Lofstrand crutches (UpQuad task), and typical upright bipedalism (UpBi task), on a treadmill. We measured the concentration of oxygenated hemoglobin (oxy-Hb) during the tasks. The oxy-Hb significantly decreased in the SMA during the HKQuad task, whereas it increased during the UpQuad task. No significant responses were observed during the UpBi task. Based on the degree of oxy-Hb responses, we ranked these locomotor tasks as UpQuad > UpBi > HKQuad. The order of the different tasks did not correspond with postural instability of the tasks. However, qualitative inspection of oxy-Hb time courses showed that oxy-Hb waveform patterns differed between upright posture tasks (peak-plateau-trough pattern for the UpQuad and UpBi tasks) and horizontal posture task (downhill pattern for the HKQuad task). Thus, the SMA may contribute to the control of truncal posture accompanying locomotor movements in humans. PMID:27413555

  2. Hemodynamic Response of the Supplementary Motor Area during Locomotor Tasks with Upright versus Horizontal Postures in Humans

    PubMed Central

    Obayashi, Shigeru; Nakajima, Katsumi; Hara, Yukihiro

    2016-01-01

    To understand cortical mechanisms related to truncal posture control during human locomotion, we investigated hemodynamic responses in the supplementary motor area (SMA) with quadrupedal and bipedal gaits using functional near-infrared spectroscopy in 10 healthy adults. The subjects performed three locomotor tasks where the degree of postural instability varied biomechanically, namely, hand-knee quadrupedal crawling (HKQuad task), upright quadrupedalism using bilateral Lofstrand crutches (UpQuad task), and typical upright bipedalism (UpBi task), on a treadmill. We measured the concentration of oxygenated hemoglobin (oxy-Hb) during the tasks. The oxy-Hb significantly decreased in the SMA during the HKQuad task, whereas it increased during the UpQuad task. No significant responses were observed during the UpBi task. Based on the degree of oxy-Hb responses, we ranked these locomotor tasks as UpQuad > UpBi > HKQuad. The order of the different tasks did not correspond with postural instability of the tasks. However, qualitative inspection of oxy-Hb time courses showed that oxy-Hb waveform patterns differed between upright posture tasks (peak-plateau-trough pattern for the UpQuad and UpBi tasks) and horizontal posture task (downhill pattern for the HKQuad task). Thus, the SMA may contribute to the control of truncal posture accompanying locomotor movements in humans. PMID:27413555

  3. Responses to Novelty and Vulnerability to Cocaine Addiction: Contribution of a Multi-Symptomatic Animal Model

    PubMed Central

    Belin, David; Deroche-Gamonet, Véronique

    2012-01-01

    Epidemiological studies have revealed striking associations between several distinct behavioral/personality traits and drug addiction, with a large emphasis on the sensation-seeking trait and the associated impulsive dimension of personality. However, in human studies, it is difficult to identify whether personality/behavioral traits actually contribute to increased vulnerability to drug addiction or reflect psychobiological adaptations to chronic drug exposure. Here we show how animal models, including the first multi-symptomatic model of addiction in the rat, have contributed to a better understanding of the relationships between different subdimensions of the sensation-seeking trait and different stages of the development of cocaine addiction, from vulnerability to initiation of cocaine self-administration to the transition to compulsive drug intake. We argue that sensation seeking predicts vulnerability to use cocaine, whereas novelty seeking, akin to high impulsivity, predicts instead vulnerability to shift from controlled to compulsive cocaine use, that is, addiction. PMID:23125204

  4. Lipopolysaccharide exposure during late embryogenesis results in diminished locomotor activity and amphetamine response in females and spatial cognition impairment in males in adult, but not adolescent rat offspring.

    PubMed

    Batinić, Bojan; Santrač, Anja; Divović, Branka; Timić, Tamara; Stanković, Tamara; Obradović, Aleksandar Lj; Joksimović, Srđan; Savić, Miroslav M

    2016-02-15

    Numerous basic and epidemiological studies have connected prenatal maternal immune activation with the occurrence of schizophrenia and/or autism. Depending on subtle differences in protocols of the used animal model, a variety of behavioral abnormalities has been reported. This study investigated behavioral differences in Wistar rat offspring of both genders, exposed to the 100 μg/kg per day dose of lipopolysaccharide (LPS) in late embryogenesis (embryonic days 15 and 16), while tested at their adolescent and young adult age (postnatal days 40 and 60, respectively). Immune activation was confirmed by detecting high levels of TNF-α and IL-6 in dam blood withdrawn 2h after the first dose of LPS. The animals were assessed in three consecutive trials of locomotor activity (novelty exploration, response to i.p. saline injection and challenge with 0.5mg/kg amphetamine), Morris water maze and social interaction tests. Overt behavioral dysfunction was perceived in adult rats only, and these changes were gender-distinctive. When compared with control rats, LPS females displayed baseline hypolocomotion and a decreased reactivity to amphetamine, while LPS males exhibited spatial learning (acquisition trials) and memory (probe trial) impairments. Prenatal treatment did not affect the time spent in social interaction. As maternal exposure to LPS in late gestation resulted in behavioral changes in offspring in early adulthood, it may model schizophrenia-like, but not autism-like endophenotypes. However, lack of a potentiated response to amphetamine testified that this model could not mimic positive symptoms, but rather certain traits of cognitive dysfunction and deficit symptoms, in males and females, respectively. PMID:26620494

  5. Effects of fentanyl administration on locomotor response in horses with the G57C μ-opioid receptor polymorphism.

    PubMed

    Wetmore, Lois A; Pascoe, Peter J; Shilo-Benjamini, Yael; Lindsey, Jane C

    2016-08-01

    OBJECTIVE To determine the locomotor response to the administration of fentanyl in horses with and without the G57C polymorphism of the μ-opioid receptor. ANIMALS 20 horses of various breeds and ages (10 horses heterozygous for the G57C polymorphism and 10 age-, breed-, and sex-matched horses that did not have the G57C polymorphism). PROCEDURES The number of steps each horse took was counted over consecutive 2-minute periods for 20 minutes to determine a baseline value. The horse then received a bolus of fentanyl (20 μg/kg, IV), and the number of steps was again counted during consecutive 2-minute periods for 60 minutes. The mean baseline value was subtracted from each 2-minute period after fentanyl administration; step counts with negative values were assigned a value of 0. Data were analyzed by use of a repeated-measures ANOVA. RESULTS Data for 19 of 20 horses (10 horses with the G57C polymorphism and 9 control horses without the G57C polymorphism) were included in the analysis. Horses with the G57C polymorphism had a significant increase in locomotor activity, compared with results for horses without the polymorphism. There was a significant group-by-time interaction. CONCLUSIONS AND CLINICAL RELEVANCE Horses heterozygous for the G57C polymorphism of the μ-opioid receptor had an increased locomotor response to fentanyl administration, compared with the response for horses without this polymorphism. The clinical impact of this finding should be investigated. PMID:27463545

  6. Computational classification of different wild-type zebrafish strains based on their variation in light-induced locomotor response.

    PubMed

    Gao, Yuan; Zhang, Gaonan; Jelfs, Beth; Carmer, Robert; Venkatraman, Prahatha; Ghadami, Mohammad; Brown, Skye A; Pang, Chi Pui; Leung, Yuk Fai; Chan, Rosa H M; Zhang, Mingzhi

    2016-02-01

    Zebrafish larvae display a rapid and characteristic swimming behaviour after abrupt light onset or offset. This light-induced locomotor response (LLR) has been widely used for behavioural research and drug screening. However, the locomotor responses have long been shown to be different between different wild-type (WT) strains. Thus, it is critical to define the differences in the WT LLR to facilitate accurate interpretation of behavioural data. In this investigation, we used support vector machine (SVM) models to classify LLR data collected from three WT strains: AB, TL and TLAB (a hybrid of AB and TL), during early embryogenesis, from 3 to 9 days post-fertilisation (dpf). We analysed both the complete dataset and a subset of the data during the first 30after light change. This initial period of activity is substantially driven by vision, and is also known as the visual motor response (VMR). The analyses have resulted in three major conclusions: First, the LLR is different between the three WT strains, and at different developmental stages. Second, the distinguishable information in the VMR is comparable to, if not better than, the full dataset for classification purposes. Third, the distinguishable information of WT strains in the light-onset response differs from that in the light-offset response. While the classification accuracies were higher for the light-offset than light-onset response when using the complete LLR dataset, a reverse trend was observed when using a shorter VMR dataset. Together, our results indicate that one should use caution when extrapolating interpretations of LLR/VMR obtained from one WT strain to another. PMID:26688204

  7. Adaptability: Conceptual and Empirical Perspectives on Responses to Change, Novelty and Uncertainty

    ERIC Educational Resources Information Center

    Martin, Andrew J.; Nejad, Harry; Colmar, Susan; Liem, Gregory Arief D.

    2012-01-01

    Adaptability is proposed as individuals' capacity to constructively regulate psycho-behavioral functions in response to new, changing, and/or uncertain circumstances, conditions and situations. The present investigation explored the internal and external validity of an hypothesised adaptability scale. The sample comprised 2,731 high school…

  8. Reinstating the Novelty P3

    PubMed Central

    Barry, Robert J.; Steiner, Genevieve Z.; De Blasio, Frances M.

    2016-01-01

    P300 (or P3) is a major positive complex in the human event-related potential, occurring some 300 ms after stimulus onset, and long thought to be the cortical correlate of the Orienting Reflex, our automatic attention-grabbing response to a novel stimulus. The Novelty P3 was the third P3 subcomponent discovered (after P3a and P3b) and appeared promising in its sensitivity to stimulus novelty, the defining characteristic of the Orienting Reflex. But some 15 years later it was claimed to be indistinguishable from the previously-discovered P3a. This led to a decline in interest in the field and confused nomenclature, with some studies using “P3a” and “Novelty P3” interchangeably. However, recent similar studies have again reported three subcomponents of the P3. Further, using single-stimulus habituation paradigms, in addition to P3a and P3b, a later decrementing P3 subcomponent has been reported, and recently labelled “HabP3” to avoid contention. We report three studies to resolve this chaotic situation, arguing for identification of the late subcomponent following the P3a and P3b as the Novelty P3. Reinstatement of the Novelty P3 as the central index of the Orienting Reflex will have widespread impact in a range of theoretical, practical, and clinical areas involving novelty processing and attention. PMID:27510599

  9. Reinstating the Novelty P3.

    PubMed

    Barry, Robert J; Steiner, Genevieve Z; De Blasio, Frances M

    2016-01-01

    P300 (or P3) is a major positive complex in the human event-related potential, occurring some 300 ms after stimulus onset, and long thought to be the cortical correlate of the Orienting Reflex, our automatic attention-grabbing response to a novel stimulus. The Novelty P3 was the third P3 subcomponent discovered (after P3a and P3b) and appeared promising in its sensitivity to stimulus novelty, the defining characteristic of the Orienting Reflex. But some 15 years later it was claimed to be indistinguishable from the previously-discovered P3a. This led to a decline in interest in the field and confused nomenclature, with some studies using "P3a" and "Novelty P3" interchangeably. However, recent similar studies have again reported three subcomponents of the P3. Further, using single-stimulus habituation paradigms, in addition to P3a and P3b, a later decrementing P3 subcomponent has been reported, and recently labelled "HabP3" to avoid contention. We report three studies to resolve this chaotic situation, arguing for identification of the late subcomponent following the P3a and P3b as the Novelty P3. Reinstatement of the Novelty P3 as the central index of the Orienting Reflex will have widespread impact in a range of theoretical, practical, and clinical areas involving novelty processing and attention. PMID:27510599

  10. ANTECEDENTS AND CONSEQUENCES OF DRUG ABUSE IN RATS SELECTIVELY BRED FOR HIGH AND LOW RESPONSE TO NOVELTY

    PubMed Central

    Flagel, Shelly B.; waselus, Maria; Clinton, Sarah M; Watson, Stanley J.; Akil, Huda

    2013-01-01

    Human genetic and epidemiological studies provide evidence that only a subset of individuals who experiment with potentially addictive drugs become addicts. What renders some individuals susceptible to addiction remains to be determined, but most would agree that there is no single trait underlying the disorder. However, there is evidence in humans that addiction liability has a genetic component, and that certain personality characteristics related to temperament (e.g. the sensation-seeking trait) are associated with individual differences in addiction liability. Consequently, we have used a selective breeding strategy based on locomotor response to a novel environment to generate two lines of rats with distinct behavioral characteristics. We have found that the resulting phenotypes differ on a number of neurobehavioral dimensions relevant to addiction. Relative to bred low-responder (bLR) rats, bred high-responder (bHR) rats exhibit increased exploratory behavior, are more impulsive, more aggressive, seek stimuli associated with rewards, and show a greater tendency to relapse. We therefore utilize this unique animal model to parse the genetic, neural and environmental factors that contribute to addiction liability. Our work shows that the glucocorticoid receptor (GR), dopaminergic molecules, and members of the fibroblast growth factor family are among the neurotransmitters and neuromodulators that play a role in both the initial susceptibility to addiction as well as the altered neural responses that follow chronic drug exposure. Moreover, our findings suggest that the hippocampus plays a major role in mediating vulnerability to addiction. It is hoped that this work will emphasize the importance of personalized treatment strategies and identify novel therapeutic targets for humans suffering from addictive disorders. PMID:23639434

  11. Modeling novelty habituation during exploratory activity in Drosophila.

    PubMed

    Soibam, Benjamin; Shah, Shishir; Gunaratne, Gemunu H; Roman, Gregg W

    2013-07-01

    Habituation is a common form of non-associative learning in which the organism gradually decreases its response to repeated stimuli. The decrease in exploratory activity of many animal species during exposure to a novel open field arena is a widely studied habituation paradigm. However, a theoretical framework to quantify how the novelty of the arena is learned during habituation is currently missing. Drosophila melanogaster display a high mean absolute activity and a high probability for directional persistence when first introduced to a novel arena. Both measures decrease during habituation to the arena. Here, we propose a phenomenological model of habituation for Drosophila exploration based on two principles: Drosophila form a spatial representation of the arena edge as a set of connected local patches, and repeated exposure to these patches is essential for the habituation of the novelty. The level of exposure depends on the number of visitations and is quantified by a variable referred to as "coverage". This model was tested by comparing predictions against the experimentally measured behavior of wild type Drosophila. The novelty habituation of wild type Canton-S depends on coverage and is specifically independent of the arena radius. Our model describes the time dependent locomotor activity, ΔD, of Canton-S using an experimentally established stochastic process Pn(ΔD), which depends on the coverage. The quantitative measures of exploration and habituation were further applied to three mutant genotypes. Consistent with a requirement for vision in novelty habituation, blind no receptor potential A(7) mutants display a failure in the decay of probability for directional persistence and mean absolute activity. The rutabaga(2080) habituation mutant also shows defects in these measures. The kurtz(1) non-visual arrestin mutant demonstrates a rapid decay in these measures, implying reduced motivation. The model and the habituation measures offer a powerful

  12. The emergence of saliency and novelty responses from Reinforcement Learning principles.

    PubMed

    Laurent, Patryk A

    2008-12-01

    Recent attempts to map reward-based learning models, like Reinforcement Learning [Sutton, R. S., & Barto, A. G. (1998). Reinforcement Learning: An introduction. Cambridge, MA: MIT Press], to the brain are based on the observation that phasic increases and decreases in the spiking of dopamine-releasing neurons signal differences between predicted and received reward [Gillies, A., & Arbuthnott, G. (2000). Computational models of the basal ganglia. Movement Disorders, 15(5), 762-770; Schultz, W. (1998). Predictive reward signal of dopamine neurons. Journal of Neurophysiology, 80(1), 1-27]. However, this reward-prediction error is only one of several signals communicated by that phasic activity; another involves an increase in dopaminergic spiking, reflecting the appearance of salient but unpredicted non-reward stimuli [Doya, K. (2002). Metalearning and neuromodulation. Neural Networks, 15(4-6), 495-506; Horvitz, J. C. (2000). Mesolimbocortical and nigrostriatal dopamine responses to salient non-reward events. Neuroscience, 96(4), 651-656; Redgrave, P., & Gurney, K. (2006). The short-latency dopamine signal: A role in discovering novel actions? Nature Reviews Neuroscience, 7(12), 967-975], especially when an organism subsequently orients towards the stimulus [Schultz, W. (1998). Predictive reward signal of dopamine neurons. Journal of Neurophysiology, 80(1), 1-27]. To explain these findings, Kakade and Dayan [Kakade, S., & Dayan, P. (2002). Dopamine: Generalization and bonuses. Neural Networks, 15(4-6), 549-559.] and others have posited that novel, unexpected stimuli are intrinsically rewarding. The simulation reported in this article demonstrates that this assumption is not necessary because the effect it is intended to capture emerges from the reward-prediction learning mechanisms of Reinforcement Learning. Thus, Reinforcement Learning principles can be used to understand not just reward-related activity of the dopaminergic neurons of the basal ganglia, but also some

  13. Environmental Control, Social Context, and Individual Differences in Behavioral and Cortisol Responses to Novelty in Infant Rhesus Monkeys

    ERIC Educational Resources Information Center

    Roma, Peter G.; Champoux, Maribeth; Suomi, Stephen J.

    2006-01-01

    The effects of appetitive controllability on behavioral and cortisol reactivity to novelty in 12 infant rhesus monkeys were studied. Surrogate-peer-reared infants had homecage access to food treats contingently via lever pressing ("master") or noncontingently ("yoked") for 12 weeks from postnatal month 2. Masters lever-pressed more, but did not…

  14. Maternal Accuracy and Behavior in Anticipating Children's Responses to Novelty: Relations to Fearful Temperament and Implications for Anxiety Development

    ERIC Educational Resources Information Center

    Kiel, Elizabeth J.; Buss, Kristin A.

    2010-01-01

    Previous research has suggested that mothers' behaviors may serve as a mechanism in the development from toddler fearful temperament to childhood anxiety. The current study examined the maternal characteristic of accuracy in predicting toddlers' distress reactions to novelty in relation to temperament, parenting, and anxiety development.…

  15. The Nicotine-Evoked Locomotor Response: A Behavioral Paradigm for Toxicity Screening in Zebrafish (Danio rerio) Embryos and Eleutheroembryos Exposed to Methylmercury

    PubMed Central

    Mora-Zamorano, Francisco X.; Svoboda, Kurt R.; Carvan, Michael J.

    2016-01-01

    This study is an adaptation of the nicotine-evoked locomotor response (NLR) assay, which was originally utilized for phenotype-based neurotoxicity screening in zebrafish embryos. Zebrafish embryos do not exhibit spontaneous swimming until roughly 4 days post-fertilization (dpf), however, a robust swimming response can be induced as early as 36 hours post-fertilization (hpf) by means of acute nicotine exposure (30–240μM). Here, the NLR was tested as a tool for early detection of locomotor phenotypes in 36, 48 and 72 hpf mutant zebrafish embryos of the non-touch-responsive maco strain; this assay successfully discriminated mutant embryos from their non-mutant siblings. Then, methylmercury (MeHg) was used as a proof-of-concept neurotoxicant to test the effectiveness of the NLR assay as a screening tool in toxicology. The locomotor effects of MeHg were evaluated in 6 dpf wild type eleutheroembryos exposed to waterborne MeHg (0, 0.01, 0.03 and 0.1μM). Afterwards, the NLR assay was tested in 48 hpf embryos subjected to the same MeHg exposure regimes. Embryos exposed to 0.01 and 0.03μM of MeHg exhibited significant increases in locomotion in both scenarios. These findings suggest that similar locomotor phenotypes observed in free swimming fish can be detected as early as 48 hpf, when locomotion is induced with nicotine. PMID:27123921

  16. Different dosing regimens of repeated ketamine administration have opposite effects on novelty processing in rats.

    PubMed

    Schumacher, Anett; Sivanandan, Brindan; Tolledo, Edgor Cole; Woldegabriel, Jacob; Ito, Rutsuko

    2016-08-01

    Repeated exposure to sub-anesthetic doses of ketamine in rats has been shown to induce cognitive deficits, as well as behavioral changes akin to the negative symptoms of schizophrenia, giving much face validity to the use of ketamine administration as a pharmacological model of schizophrenia. This study sought to further characterize the behavioral effects of two different ketamine pre-treatment regimens, focusing primarily on the effects of repeated ketamine administration on novelty processing, a capacity that is disrupted in schizophrenia. Rats received 5 or 14 intra-peritoneal injections of 30mg/kg ketamine or saline across 5 or 7days, respectively. They were then tested in an associative mismatch detection task to examine their ability to detect novel configurations of familiar audio-visual sequences. Furthermore, rats underwent a sequential novel object and novel object location exploration task. Subsequently, rats were also tested on the delayed matching to place T-maze task, sucrose preference task and locomotor tests involving administering a challenge dose of amphetamine (AMPH). The high-dose ketamine pre-treatment regimen elicited impairments in mismatch detection and working memory. In contrast, the low-dose ketamine pre-treatment regimen improved performance of novelty detection. In addition, low-dose ketamine pre-treated rats showed locomotor sensitization following an AMPH challenge, while the high-dose ketamine pre-treated rats showed an attenuated locomotor response to AMPH, compared to control rats. These findings demonstrate that different regimens of repeated ketamine administration induce alterations in novelty processing in opposite directions, and that differential neural adaptations occurring in the mesolimbic dopamine system may underlie these effects. PMID:27064663

  17. Assessment of Postflight Locomotor Performance Utilizing a Test of Functional Mobility: Strategic and Adaptive Responses

    NASA Technical Reports Server (NTRS)

    Warren, L. E.; Mulavara, A. P.; Peters, B. T.; Cohen, H. S.; Richards, J. T.; Miller, C. A.; Brady, R.; Ruttley, T. M.; Bloomberg, J. J.

    2006-01-01

    Space flight induces adaptive modification in sensorimotor function, allowing crewmembers to operate in the unique microgravity environment. This adaptive state, however, is inappropriate for a terrestrial environment. During a re-adaptation period upon their return to Earth, crewmembers experience alterations in sensorimotor function, causing various disturbances in perception, spatial orientation, posture, gait, and eye-head coordination. Following long duration space flight, sensorimotor dysfunction would prevent or extend the time required to make an emergency egress from the vehicle; compromising crew safety and mission objectives. We are investigating two types of motor learning that may interact with each other and influence a crewmember's ability to re-adapt to Earth's gravity environment. In strategic learning, crewmembers make rapid modifications in their motor control strategy emphasizing error reduction. This type of learning may be critical during the first minutes and hours after landing. In adaptive learning, long-term plastic transformations occur, involving morphological changes and synaptic modification. In recent literature these two behavioral components have been associated with separate brain structures that control the execution of motor strategies: the strategic component was linked to the posterior parietal cortex and the adaptive component was linked to the cerebellum (Pisella, et al. 2004). The goal of this paper was to demonstrate the relative contributions of the strategic and adaptive components to the re-adaptation process in locomotor control after long duration space flight missions on the International Space Station (ISS). The Functional Mobility Test (FMT) was developed to assess crewmember s ability to ambulate postflight from an operational and functional perspective. Sixteen crewmembers were tested preflight (3 sessions) and postflight (days 1, 2, 4, 7, 25) following a long duration space flight (approx 6 months) on the ISS. We

  18. Assessment of Postflight Locomotor Performance Utilizing a Test of Functional Mobility: Strategic and Adaptive Responses

    NASA Technical Reports Server (NTRS)

    Warren, L. E.; Mulavara, A. P.; Peters, B. T.; Cohen, H. S.; Richards, J. T.; Miller, C. A.; Brady, R.; Ruttley, T. M.; Bloomberg, J. J.

    2006-01-01

    Space flight induces adaptive modification in sensorimotor function, allowing crewmembers to operate in the unique microgravity environment. This adaptive state, however, is inappropriate for a terrestrial environment. During a re-adaptation period upon their return to Earth, crewmembers experience alterations in sensorimotor function, causing various disturbances in perception, spatial orientation, posture, gait, and eye-head coordination. Following long duration space flight, sensorimotor dysfunction would prevent or extend the time required to make an emergency egress from the vehicle; compromising crew safety and mission objectives. We are investigating two types of motor learning that may interact with each other and influence a crewmember's ability to re-adapt to Earth's gravity environment. In strategic learning, crewmembers make rapid modifications in their motor control strategy emphasizing error reduction. This type of learning may be critical during the first minutes and hours after landing. In adaptive learning, long-term plastic transformations occur, involving morphological changes and synaptic modification. In recent literature these two behavioral components have been associated with separate brain structures that control the execution of motor strategies: the strategic component was linked to the posterior parietal cortex and the adaptive component was linked to the cerebellum (Pisella, et al. 2004). The goal of this paper was to demonstrate the relative contributions of the strategic and adaptive components to the re-adaptation process in locomotor control after long duration space flight missions on the International Space Station (ISS). The Functional Mobility Test (FMT) was developed to assess crewmember s ability to ambulate postflight from an operational and functional perspective. Sixteen crewmembers were tested preflight (3 sessions) and postflight (days 1, 2, 4, 7, 25) following a long duration space flight (approx 6 months) on the ISS. We

  19. Chronic cocaine or ethanol exposure during adolescence alters novelty-related behaviors in adulthood.

    PubMed

    Stansfield, Kirstie H; Kirstein, Cheryl L

    2007-04-01

    Adolescence is a time of high-risk behavior and increased exploration. This developmental period is marked by a greater probability to initiate drug use and is associated with an increased risk to develop addiction and adulthood dependency and drug use at this time is associated with an increased risk. Human adolescents are predisposed toward an increased likelihood of risk-taking behaviors [Zuckerman M. Sensation seeking and the endogenous deficit theory of drug abuse. NIDA Res Monogr 1986;74:59-70.], including drug use or initiation. In the present study, adolescent animals were exposed to twenty days of either saline (0.9% sodium chloride), cocaine (20 mg/kg) or ethanol (1 g/kg) i.p. followed by a fifteen-day washout period. All animals were tested as adults on several behavioral measures including locomotor activity induced by a novel environment, time spent in the center of an open field, novelty preference and novel object exploration. Animals exposed to cocaine during adolescence and tested as adults exhibited a greater locomotor response in a novel environment, spent less time in the center of the novel open field and spent less time with a novel object, results that are indicative of a stress or anxiogenic response to novelty or a novel situation. Adolescent animals chronically administered ethanol and tested as adults, unlike cocaine-exposed were not different from controls in a novel environment, indicated by locomotor activity or time spent with a novel object. However, ethanol-exposed animals approached the novel object more, suggesting that exposure to ethanol during development may result in less-inhibited behaviors during adulthood. The differences in adult behavioral responses after drug exposure during adolescence are likely due to differences in the mechanisms of action of the drugs and subsequent reward and/or stress responsivity. Future studies are needed to determine the neural substrates of these long lasting drug-induced changes. PMID

  20. Locomotor and Stress Responses to Nicotine Differ in Adolescent and Adult Rats

    PubMed Central

    Cao, Junran; Belluzzi, James D.; Loughlin, Sandra E.; Dao, Jasmin M.; Chen, YiLing; Leslie, Frances M.

    2010-01-01

    Since adolescence is a critical period for the initiation of tobacco use, we have systematically compared behavioral and endocrine responses to nicotine in Sprague-Dawley rats of both sexes at early adolescence (postnatal day (P) 28), mid- adolescence (P38) and adulthood (P90). Locomotion and center time in a novel open field were evaluated for 30 min following intravenous injection of saline or nicotine (60 µg/kg), followed by measurement of plasma corticosterone. Complex age and sex differences in behavioral and endocrine response were observed, which were dependent on the functional endpoint examined. Whereas there were age differences in nicotine effects on all functional measures, sex differences were largely restricted to adult stress-related corticosterone and center-time responses. Although significant drug effects were detected at P28 and P90, there was no effect of nicotine at P38 on any measure examined. In saline-treated males, but not females, there were significant positive correlations across age between initial ambulatory counts and both initial vertical counts and total center time. Nicotine treatment increased correlations in both sexes, and yielded a significant negative interaction between initial ambulatory counts and plasma corticosterone. The unique responses of adolescents to nicotine are consistent with an immature function of nicotinic acetylcholine receptors at this age. PMID:20423718

  1. Locomotor and behavioural responses of empire gudgeons (Hypseleotris compressa) exposed to coal mine wastewater.

    PubMed

    Lanctôt, C; Melvin, S D; Leusch, F D L; Wilson, S; Fabbro, L

    2016-02-01

    Coal mining generates large quantities of complex effluent and may pose a threat to aquatic wildlife. Despite this, few studies have explored the consequences of exposure to mine wastewater on aquatic organisms, and this is particularly true for the Australian environment. We investigated sub-lethal behavioural responses in a native Australian fish exposed to wastewater from two releasing dams (CMW1 and CMW2) located at an open cut coal mine in Central Queensland. Swimming activity and movement of empire gudgeons (Hypseleotris compressa) were assessed during a two-week exposure using video-tracking software. Increased activity was observed in exposed fish after 7 and 14 days. Specifically, we found a significant increase in the mean velocity and mobility of fish exposed to CMW1 treatments. Exposed fish also spent on average 23% more time in the peripheral zone compared to controls after 14-d exposures. A similar response pattern was observed in fish exposed to CMW2, but differences between treated and control fish did not generally reach statistical significance. Alterations to normal swimming activity and movement patterns can be indicative of a stress response in fish, and could subsequently lead to negative population-level impacts by increasing the conspicuousness of exposed individuals to predators, or by altering foraging abilities. More research is warranted to explore relationships between behavioural and physiological outcomes, including endocrine disruption, and subsequent population-level outcomes in aquatic organisms at risk of exposure to coal process-affected water. PMID:26517382

  2. Antennal and locomotor responses to attractive and aversive odors in the searching cockroach.

    PubMed

    Nishiyama, Katsuhiro; Okada, Jiro; Toh, Yoshihiro

    2007-09-01

    The behavioral responses to attractive and aversive odors were examined in blinded adult male cockroaches under tethered-walking conditions. A sex pheromone-like stimulant derived from adult virgin females and artificially synthesized limonene were used as attractive and aversive odor sources, respectively. When a searching animal was stimulated with the attractive female-derived odor, the horizontal deflections of both the antennae were increased, and in most cases the vertical antennal positions were shifted downward. The stimulation also significantly decreased the walking speed of the animal. These behavioral changes imply a careful search in the immediate surroundings. The aftereffect of the sex pheromone was more pronounced on locomotion than on antennal movement. On the other hand, stimulation with the aversive odor (limonene) tended to suppress active antennal movement, and also increased the walking speed. Immediately after the withdrawal of the aversive odor, the active movement of the antennae was resumed, and the walking speed rapidly decreased to a level approximately the same as that of the control period. These results indicate that the responses to the qualitatively opposite types of odor are reciprocal to each other with regard to both antennal movement and locomotion. PMID:17609964

  3. Neurotransmitters and Novelty: A Systematic Review.

    PubMed

    Rangel-Gomez, Mauricio; Meeter, Martijn

    2016-01-01

    Our brains are highly responsive to novelty. However, how novelty is processed in the brain, and what neurotransmitter systems play a role therein, remains elusive. Here, we systematically review studies on human participants that have looked at the neuromodulatory basis of novelty detection and processing. While theoretical models and studies on nonhuman animals have pointed to a role of the dopaminergic, cholinergic, noradrenergic and serotonergic systems, the human literature has focused almost exclusively on the first two. Dopamine was found to affect electrophysiological responses to novelty early in time after stimulus presentation, but evidence on its effects on later processing was found to be contradictory: While neuropharmacological studies mostly yielded null effects, gene studies did point to an important role for dopamine. Acetylcholine seems to dampen novelty signals in the medial temporal lobe, but boost them in frontal cortex. Findings on 5-HT (serotonin) were found to be mostly contradictory. Two large gaps were identified in the literature. First, few studies have looked at neuromodulatory influences on behavioral effects of novelty. Second, no study has looked at the involvement of the noradrenergic system in novelty processing. PMID:26601905

  4. Medial hypothalamic 5-hydroxytryptamine (5-HT)1A receptors regulate neuroendocrine responses to stress and exploratory locomotor activity: application of recombinant adenovirus containing 5-HT1A sequences.

    PubMed

    Li, Qian; Holmes, Andrew; Ma, Li; Van de Kar, Louis D; Garcia, Francisca; Murphy, Dennis L

    2004-12-01

    Our previous studies found that serotonin transporter (SERT) knock-out mice showed increased sensitivity to minor stress and increased anxiety-like behavior but reduced locomotor activity. These mice also showed decreased density of 5-hydroxytryptamine (5-HT1A) receptors in the hypothalamus, amygdala, and dorsal raphe. To evaluate the contribution of hypothalamic 5-HT1A receptors to these phenotypes of SERT knock-out mice, two studies were conducted. Recombinant adenoviruses containing 5-HT1A sense and antisense sequences (Ad-1AP-sense and Ad-1AP-antisense) were used to manipulate 5-HT1A receptors in the hypothalamus. The expression of the 5-HT1A genes is controlled by the 5-HT1A promoter, so that they are only expressed in 5-HT1A receptor-containing cells. (1) Injection of Ad-1AP-sense into the hypothalamus of SERT knock-out mice restored 5-HT1A receptors in the medial hypothalamus; this effect was accompanied by elimination of the exaggerated adrenocorticotropin responses to a saline injection (minor stress) and reduced locomotor activity but not by a change in increased exploratory anxiety-like behavior. (2) To further confirm the observation in SERT-/- mice, Ad-1AP-antisense was injected into the hypothalamus of normal mice. The density and the function of 5-HT1A receptors in the medial hypothalamus were significantly reduced in Ad-1AP-antisense-treated mice. Compared with the control group (injected with Ad-track), Ad-1A-antisense-treated mice showed a significant reduction in locomotor activity, but again no changes in exploratory anxiety-like behaviors, tested by elevated plus-maze and open-field tests. Thus, the present results demonstrate that medial hypothalamic 5-HT1A receptors regulate stress responses and locomotor activity but may not regulate exploratory anxiety-like behaviors. PMID:15574737

  5. Locomotor micro-activities associated with therapeutic responses in patients with seasonal affective disorders

    PubMed Central

    Ohashi, Kyoko; Yamamoto, Yoshiharu; Teicher, Martin H.

    2015-01-01

    Background Psychomotor retardation, leaden paralysis and fatigue are often used to describe patients with depressive disorders. However, there is limited understanding of their meaning and how they are objectively manifested in the physical world. Patients with seasonal affective disorder (SAD) are characteristically hypoactive, and experience restoration in energy during effective treatment with bright light. In this study, we attempt to identify quantitative metrics of psychomotor activity that correspond to the clinical perceptions of hypoactivity and to the early activating effects of treatment. Methods Novel means of assessing the microstructure of activity was employed using wavelets and Hurst exponents to indicate the proclivity of subjects to persist at higher and lower levels of activity. This was assesed using actigraphs in 16 unmedicated patients with SAD before and following two weeks of bright light therapy. Results Two weeks of phototherapy had no significant effect on mean levels of diurnal activity, but altered the microstructure of the activity. Specifically, phototherapy produced a significant reduction in inertial resistance in patients who had a 50% or greater reduction in Hamilton Depression scores (n=8), as reflected in reduced tendency to persist at low levels of activity. There was also a strong correlation between ratings of fatigue and measures of persistence at high versus low activity in initial responders, but not in initial non-responders. Conclusion These findings suggest that light therapy alters the nature of diurnal activity troughs in early responsive patients, reducing their tendency to persist at low levels, possibly reflecting an alleviation of psychomotor retardation. PMID:27135034

  6. Novelty or Surprise?

    PubMed Central

    Barto, Andrew; Mirolli, Marco; Baldassarre, Gianluca

    2013-01-01

    Novelty and surprise play significant roles in animal behavior and in attempts to understand the neural mechanisms underlying it. They also play important roles in technology, where detecting observations that are novel or surprising is central to many applications, such as medical diagnosis, text processing, surveillance, and security. Theories of motivation, particularly of intrinsic motivation, place novelty and surprise among the primary factors that arouse interest, motivate exploratory or avoidance behavior, and drive learning. In many of these studies, novelty and surprise are not distinguished from one another: the words are used more-or-less interchangeably. However, while undeniably closely related, novelty and surprise are very different. The purpose of this article is first to highlight the differences between novelty and surprise and to discuss how they are related by presenting an extensive review of mathematical and computational proposals related to them, and then to explore the implications of this for understanding behavioral and neuroscience data. We argue that opportunities for improved understanding of behavior and its neural basis are likely being missed by failing to distinguish between novelty and surprise. PMID:24376428

  7. Novel technology for modulating locomotor activity as an operant response in the mouse: implications for neuroscience studies involving “exercise” in rodents

    PubMed Central

    Fantegrossi, William E.; Xiao, Wenjie; Zimmerman, Sarah M.

    2012-01-01

    We have developed a novel, low-cost device designed to monitor and modulate locomotor activity in murine subjects. This technology has immediate application to the study of effects of physical exercise on various neurobiological endpoints, and will also likely be useful in the study of psychomotor sensitization and drug addiction. Here we demonstrate the capacity of these devices to establish locomotor activity as an operant response reinforced by food pellet presentations, and show that schedules of reinforcement can reliably control this behavior. Importantly, these data show that varying degrees of increased locomotor activity (in other words, “exercise”) can be elicited and maintained in mice by manipulating the schedule of reinforcement. Our findings argue that the present technology might reduce the imposition of stress and motivational bias inherent in more traditional procedures for establishing exercise in laboratory rodents, while allowing for true random assignment to experimental groups. As interest in physical exercise as a modulating factor in numerous clinical conditions continues to grow, technologies like the one proposed here are likely to become critical in conducting future experiments along these lines. PMID:23164960

  8. Enhancement of amphetamine-induced locomotor response in rats on different regimens of diet restriction and 2-deoxy-D-glucose treatment.

    PubMed

    Mamczarz, J; Bowker, J L; Duffy, K; Zhu, M; Hagepanos, A; Ingram, D K

    2005-01-01

    Diet restriction (DR) in rodents increases lifespan, reduces age-related disease and pathology, increases stress responses, and maintains better function later into life compared with conventional ad libitum (AL) feeding. We have been investigating different DR regimens and also DR mimetics that stimulate stress response pathways that are activated by DR. By inhibiting glycolysis, feeding or injection of 2-deoxy-D-glucose (2DG) has been proposed as a DR mimetic and has been shown to provide neuroprotection. In the current study, we examined whether 2DG treatment produces behavioral changes similar to those observed in DR rats following stimulation of the dopaminergic (DA) system by D-amphetamine (AMPH). Male Fischer 344 rats were maintained on different dietary regimens: 40% daily DR (40% DR); every-other-day feeding (EOD); or AL with some groups provided food containing 0.4% 2DG or injected i.p. with 2DG. In addition, we examined the persistence of effects of DR or 2DG feeding after switching rats to AL. When locomotor activity was assessed at different time points following initiation of dietary treatments, we noted that the enhancement of AMPH-induced locomotor responses emerged earlier in DR rats than observed in 2DG fed rats, but 40% DR and EOD rats responded in a similar manner. Enhanced locomotor responses persisted in 2DG fed rats even when returned to normal diet for 1 month and in the case of DR rats even after 2 months of AL feeding. Three weeks of 2DG injections also enhanced AMPH response, but this effect was transient. The most important finding was that 2DG did not affect body weight or diet intake yet had effects similar to DR. Thus, 2DG appears to activate DA pathways in the same direction as DR does but without the necessity of reducing caloric intake. PMID:15708486

  9. Vasotocin neurons and septal V1a-like receptors potently modulate songbird flocking and responses to novelty.

    PubMed

    Kelly, Aubrey M; Kingsbury, Marcy A; Hoffbuhr, Kristin; Schrock, Sara E; Waxman, Brandon; Kabelik, David; Thompson, Richmond R; Goodson, James L

    2011-06-01

    Previous comparisons of territorial and gregarious finches (family Estrildidae) suggest the hypothesis that arginine vasotocin (VT) neurons in the medial bed nucleus of the stria terminalis (BSTm) and V(1a)-like receptors in the lateral septum (LS) promote flocking behavior. Consistent with this hypothesis, we now show that intraseptal infusions of a V(1a) antagonist in male zebra finches (Taeniopygia guttata) reduce gregariousness (preference for a group of 10 versus 2 conspecific males), but have no effect on the amount of time that subjects spend in close proximity to other birds ("contact time"). The antagonist also produces a profound increase in anxiety-like behavior, as exhibited by an increased latency to feed in a novelty-suppressed feeding test. Bilateral knockdown of VT production in the BSTm using LNA-modified antisense oligonucleotides likewise produces increases in anxiety-like behavior and a potent reduction in gregariousness, relative to subjects receiving scrambled oligonucleotides. The antisense oligonucleotides also produced a modest increase in contact time, irrespective of group size. Together, these combined experiments provide clear evidence that endogenous VT promotes preferences for larger flock sizes, and does so in a manner that is coupled to general anxiolysis. Given that homologous peptide circuitry of the BSTm-LS is found across all tetrapod vertebrate classes, these findings may be predictive for other highly gregarious species. PMID:21295577

  10. Vasotocin Neurons and Septal V1a-like Receptors Potently Modulate Songbird Flocking and Responses to Novelty

    PubMed Central

    Kelly, Aubrey M.; Kingsbury, Marcy A.; Hoffbuhr, Kristin; Schrock, Sara E.; Waxman, Brandon; Kabelik, David; Thompson, Richmond R.; Goodson, James L.

    2011-01-01

    Previous comparisons of territorial and gregarious finches (family Estrildidae) suggest the hypothesis that arginine vasotocin (VT) neurons in the medial bed nucleus of the stria terminalis (BSTm) and V1a-like receptors in the lateral septum (LS) promote flocking behavior. Consistent with this hypothesis, we now show that intraseptal infusions of a V1a antagonist in male zebra finches (Taeniopygia guttata) reduce gregariousness (preference for a group of 10 versus 2 conspecific males), but have no effect on the amount of time that subjects spend in close proximity to other birds (“contact time”). The antagonist also produces a profound increase in anxiety-like behavior, as exhibited by an increased latency to feed in a novelty-suppressed feeding test. Bilateral knockdown of VT production in the BSTm using LNA-modified antisense oligonucleotides likewise produces increases in anxiety-like behavior and a potent reduction in gregariousness, relative to subjects receiving scrambled oligonucleotides. The antisense oligonucleotides also produced a modest increase in contact time (irrespective of group size). Together, these combined experiments provide clear evidence that endogenous VT promotes preferences for larger flock sizes, and does so in a manner that is coupled to general anxiolysis. Given that homologous peptide circuitry of the BSTm-LS is found across all tetrapod vertebrate classes, these findings may be predictive for other highly gregarious species. PMID:21295577

  11. CCK-8 injected into the nucleus accumbens attenuates the supersensitive locomotor response to apomorphine in 6-OHDA and chronic-neuroleptic treated rats.

    PubMed

    Weiss, F; Ettenberg, A; Koob, G F

    1989-01-01

    Postsynaptic dopamine-cholecystokinin (CCK) interactions in the nucleus accumbens were studied in two behavioral preparations of DA receptor supersensitivity: chronic-neuroleptic treated and 6-hydroxydopamine (6-OHDA) denervated rats. Subcutaneous (SC) injections of apomorphine (APO; 0.15 mg/kg) in experiment 1 produced marked hyperlocomotion in rats following 12 days of pretreatment with cis-[Z]-flupenthixol (2 mg/kg; twice per day). Bilateral intra-accumbens (N.Acc.) microinjections of CCK-8 (2 ng and 2 micrograms) reliably reduced APO-stimulated hyperlocomotion. An intermediate CCK dose (20 ng) was without effect. No change in APO responsivity following chronic vehicle treatment was observed and the baseline APO response was not altered by CCK at any dose. Denervation of mesolimbic dopamine (DA) terminals by intra-N.Acc. injections of 6-hydroxydopamine (6-OHDA; 8 micrograms/side) in experiment 2 similarly resulted in intense locomotor hyperactivity after APO stimulation (0.1 mg/kg; SC). Bilateral intra-N.Acc. injections of CCK-8 (1, 10, 100 ng, and 1 micrograms) significantly attenuated the supersensitive locomotor response to APO. As in experiment 1, CCK produced "biphasic" dose-response effects with strong attenuation that persisted throughout the entire 60-min test at both high (1 microgram) and low (1 ng) doses. Intermediate CCK doses (10 and 100 ng) produced only short-term reductions in activity. Hypomotility induced by APO in SHAM-lesioned rats was not effectively reversed by CCK treatments. CCK had no effect on unstimulated baseline locomotor activity in either 6-OHDA or SHAM-lesioned rats. These results provide further evidence that CCK-8 modulates mesolimbic DA activity by functionally opposing the postsynaptic effects of DA in the region of the nucleus accumbens. PMID:2574480

  12. Novelty shop 'itching powder'.

    PubMed

    Albert, M R

    1998-08-01

    To evaluate causes of itch, commercial 'itching powders' were sought for evaluation. Only one product, produced in Germany and consisting of ground rose hips, is currently sold in novelty shops in the Boston area. These plant fibres appear to provoke itch and prickle sensations by non-allergic mechanical stimulation, similar to the action of wool fibres. PMID:9737050

  13. R7BP Complexes With RGS9-2 and RGS7 in the Striatum Differentially Control Motor Learning and Locomotor Responses to Cocaine

    PubMed Central

    Anderson, Garret R; Cao, Yan; Davidson, Steve; Truong, Hai V; Pravetoni, Marco; Thomas, Mark J; Wickman, Kevin; Giesler, Glenn J; Martemyanov, Kirill A

    2010-01-01

    In the striatum, signaling through G protein-coupled dopamine receptors mediates motor and reward behavior, and underlies the effects of addictive drugs. The extent of receptor responses is determined by RGS9-2/Gβ5 complexes, a striatally enriched regulator that limits the lifetime of activated G proteins. Recent studies suggest that the function of RGS9-2/Gβ5 is controlled by the association with an additional subunit, R7BP, making elucidation of its contribution to striatal signaling essential for understanding molecular mechanisms of behaviors mediated by the striatum. In this study, we report that elimination of R7BP in mice results in motor coordination deficits and greater locomotor response to morphine administration, consistent with the essential role of R7BP in maintaining RGS9-2 expression in the striatum. However, in contrast to previously reported observations with RGS9-2 knockouts, mice lacking R7BP do not show higher sensitivity to locomotor-stimulating effects of cocaine. Using a striatum-specific knockdown approach, we show that the sensitivity of motor stimulation to cocaine is instead dependent on RGS7, whose complex formation with R7BP is dictated by RGS9-2 expression. These results indicate that dopamine signaling in the striatum is controlled by concerted interplay between two RGS proteins, RGS7 and RGS9-2, which are balanced by a common subunit, R7BP. PMID:20043004

  14. Resolution of a target-tracking optical novelty filter

    NASA Technical Reports Server (NTRS)

    Liu, Duncan T. H.; Cheng, Li-Jen

    1991-01-01

    The resolution of a target-tracking optical novelty filter is discussed in terms of the response time of the nonlinear medium, the speed of the target, and the resolution of the input device. Optical novelty filters using a faster nonlinear medium may have a higher output resolution. This is particularly true in the case of tracking high-speed targets. The potential of implementing high-resolution optical novelty filters using photorefractive GaAs is investigated experimentally.

  15. Biomimetic novelty detection

    NASA Astrophysics Data System (ADS)

    Ma, Lein W.; Szu, Harold

    2010-04-01

    In the crowded rain forest, how do animals locate camouflaged prey that resemble the environment, such as walking sticks? Birds will observe the suspected stick over a period of time to determine if its behavior matches that of a tree. If the stick's behavior exceeds normal tree behavior, such as moving faster than the other branches, the bird will determine that it is actually a walking stick and not a tree branch. Once this determination is made, they will prey on the insect. Studying this natural process of novelty detection, present in a variety of animals from birds to turkey vultures, can be beneficial for numerous human applications. The spatiotemporal novelty detector will be developed using self-referencing matched filters to go beyond auto-regression. This algorithm is more than the usual change detector for it will detect a novelty behavior that exceeds its predicted value based on past data, e.g. the bird who identifies a walking stick in the forest. A scalar model is presented; however, the application can be expanded to multiple modalities for more detailed applications. Some of these applications include gas pipeline leak detection, persistent surveillance, and the creation of a smart sensor web.

  16. Fluoxetine exposure during pregnancy and lactation: Effects on acute stress response and behavior in the novelty-suppressed feeding are age and gender-dependent in rats.

    PubMed

    Francis-Oliveira, José; Ponte, Bianca; Barbosa, Ana Paula Moreno; Veríssimo, Luiz Fernando; Gomes, Marcus Vinícius; Pelosi, Gislaine Garcia; Britto, Luiz Roberto Giorgetti de; Moreira, Estefânia Gastaldello

    2013-09-01

    Fluoxetine (FLX) is commonly used to treat anxiety and depressive disorders in pregnant women. Since FLX crosses the placenta and is excreted in milk, maternal treatment with this antidepressant may expose the fetus and neonate to increased levels of serotonin (5-HT). Long-term behavioral abnormalities have been reported in rodents exposed to higher levels of 5-HT during neurodevelopment. In this study we evaluated if maternal exposure to FLX during pregnancy and lactation would result in behavioral and/or stress response disruption in adolescent and adult rats. Our results indicate that exposure to FLX influenced restraint stress-induced Fos expression in the amygdala in a gender and age-specific manner. In male animals, a decreased expression was observed in the basolateral amygdala at adolescence and adulthood; whereas at adulthood, a decrease was also observed in the medial amygdala. A lack of FLX exposure effect was observed in females and also in the paraventricular nucleus of both genders. Regarding the behavioral evaluation, FLX exposure did not induce anhedonia in the sucrose preference test but decreased the latency to feed of both male and female adolescent rats evaluated in the novelty-suppressed feeding test. In conclusion, FLX exposure during pregnancy and lactation decreases acute amygdalar stress response to a psychological stressor in males (adolescents and adults) as well as influences the behavior of adolescents (males and females) in a model that evaluates anxiety and/or depressive-like behavior. Even though FLX seems to be a developmental neurotoxicant, the translation of these findings to human safe assessment remains to be determined since it is recognized that not treating a pregnant or lactating woman may also impact negatively the development of the descendants. PMID:23764459

  17. Involvement of the TRPV1 channel in the modulation of spontaneous locomotor activity, physical performance and physical exercise-induced physiological responses.

    PubMed

    Hudson, A S R; Kunstetter, A C; Damasceno, W C; Wanner, S P

    2016-01-01

    Physical exercise triggers coordinated physiological responses to meet the augmented metabolic demand of contracting muscles. To provide adequate responses, the brain must receive sensory information about the physiological status of peripheral tissues and organs, such as changes in osmolality, temperature and pH. Most of the receptors involved in these afferent pathways express ion channels, including transient receptor potential (TRP) channels, which are usually activated by more than one type of stimulus and are therefore considered polymodal receptors. Among these TRP channels, the TRPV1 channel (transient receptor potential vanilloid type 1 or capsaicin receptor) has well-documented functions in the modulation of pain sensation and thermoregulatory responses. However, the TRPV1 channel is also expressed in non-neural tissues, suggesting that this channel may perform a broad range of functions. In this review, we first present a brief overview of the available tools for studying the physiological roles of the TRPV1 channel. Then, we present the relationship between the TRPV1 channel and spontaneous locomotor activity, physical performance, and modulation of several physiological responses, including water and electrolyte balance, muscle hypertrophy, and metabolic, cardiovascular, gastrointestinal, and inflammatory responses. Altogether, the data presented herein indicate that the TPRV1 channel modulates many physiological functions other than nociception and thermoregulation. In addition, these data open new possibilities for investigating the role of this channel in the acute effects induced by a single bout of physical exercise and in the chronic effects induced by physical training. PMID:27191606

  18. Involvement of the TRPV1 channel in the modulation of spontaneous locomotor activity, physical performance and physical exercise-induced physiological responses

    PubMed Central

    Hudson, A.S.R.; Kunstetter, A.C.; Damasceno, W.C.; Wanner, S.P.

    2016-01-01

    Physical exercise triggers coordinated physiological responses to meet the augmented metabolic demand of contracting muscles. To provide adequate responses, the brain must receive sensory information about the physiological status of peripheral tissues and organs, such as changes in osmolality, temperature and pH. Most of the receptors involved in these afferent pathways express ion channels, including transient receptor potential (TRP) channels, which are usually activated by more than one type of stimulus and are therefore considered polymodal receptors. Among these TRP channels, the TRPV1 channel (transient receptor potential vanilloid type 1 or capsaicin receptor) has well-documented functions in the modulation of pain sensation and thermoregulatory responses. However, the TRPV1 channel is also expressed in non-neural tissues, suggesting that this channel may perform a broad range of functions. In this review, we first present a brief overview of the available tools for studying the physiological roles of the TRPV1 channel. Then, we present the relationship between the TRPV1 channel and spontaneous locomotor activity, physical performance, and modulation of several physiological responses, including water and electrolyte balance, muscle hypertrophy, and metabolic, cardiovascular, gastrointestinal, and inflammatory responses. Altogether, the data presented herein indicate that the TPRV1 channel modulates many physiological functions other than nociception and thermoregulation. In addition, these data open new possibilities for investigating the role of this channel in the acute effects induced by a single bout of physical exercise and in the chronic effects induced by physical training. PMID:27191606

  19. The 'GALS' locomotor screen.

    PubMed Central

    Doherty, M; Dacre, J; Dieppe, P; Snaith, M

    1992-01-01

    The locomotor system is complex and difficult to examine. A selective clinical process to detect important locomotor abnormalities and functional disability could prove valuable. A screen based on a tested 'minimal' history and examination system is described, together with a simple method of recording. The screen is fast and easy to perform. As well as providing a useful introduction to examination of the locomotor system, the screen includes objective observation of functional movements relevant to activities of daily living. Its inclusion in the undergraduate clerking repertoire could improve junior doctors' awareness and recognition of rheumatic disease and general disability. It could also provide a valuable screening test for use in general practice. Images PMID:1444632

  20. Locomotor exercise in weightlessness

    NASA Technical Reports Server (NTRS)

    Thornton, W.; Whitmore, H.

    1991-01-01

    The requirements for exercise in space by means of locomotion are established and addressed with prototype treadmills for use during long-duration spaceflight. The adaptation of the human body to microgravity is described in terms of 1-G locomotor biomechanics, the effects of reduced activity, and effective activity-replacement techniques. The treadmill is introduced as a complement to other techniques of force replacement with reference given to the angle required for exercise. A motor-driven unit is proposed that can operate at a variety of controlled speeds and equivalent grades. The treadmills permit locomotor exercise as required for long-duration space travel to sustain locomotor and cardiorespiratory capacity at a level consistent with postflight needs.

  1. Human hippocampal processing of environmental novelty during spatial navigation.

    PubMed

    Kaplan, Raphael; Horner, Aidan J; Bandettini, Peter A; Doeller, Christian F; Burgess, Neil

    2014-07-01

    The detection and processing of novel information encountered as we explore our environment is crucial for learning and adaptive behavior. The human hippocampus has been strongly implicated in laboratory tests of novelty detection and episodic memory, but has been less well studied during more ethological tasks such as spatial navigation, typically used in animals. We examined fMRI BOLD activity as a function of environmental and object novelty as humans performed an object-location virtual navigation task. We found greater BOLD response to novel relative to familiar environments in the hippocampus and adjacent parahippocampal gyrus. Object novelty was associated with increased activity in the posterior parahippocampal/fusiform gyrus and anterior hippocampus extending into the amygdala and superior temporal sulcus. Importantly, whilst mid-posterior hippocampus was more sensitive to environmental novelty than object novelty, the anterior hippocampus responded similarly to both forms of novelty. Amygdala activity showed an increase for novel objects that decreased linearly over the learning phase. By investigating how participants learn and use different forms of information during spatial navigation, we found that medial temporal lobe (MTL) activity reflects both the novelty of the environment and of the objects located within it. This novelty processing is likely supported by distinct, but partially overlapping, sets of regions within the MTL. PMID:24550152

  2. Locomotor responses of human CD45 lymphocyte subsets: preferential locomotion of CD45RO+ lymphocytes in response to attractants and mitogens.

    PubMed Central

    Newman, I; Wilkinson, P C

    1993-01-01

    The CD45RO+ population of lymphocytes from human blood contains a higher proportion of locomotor cells than the CD45RA+ population. Direct from blood there were few locomotor lymphocytes (< 15%), but, among these, a higher proportion of CD45RO+ than of CD45RA+ cells responded to the chemotactic stimuli, foetal calf serum (FCS) and interleukin-2 (IL-2) in polarization assays. Likewise, after overnight culture, a higher proportion of CD45RO+ cells responded to IL-8. Culture for 24-72 hr in activators such as anti-CD3, purified protein derivative (PPD), phytohaemagglutinin (PHA), concanavalin A (Con A), pokeweed mitogen (PWM) or in an allogeneic mixed leucocyte reaction (AMLR) increased the proportion of locomotor lymphocytes to 20-60%, and the CD45RO+ subset showed proportionately more polarized cells than the CD45RA+ subset after culture with all the above activators. Preferential migration of CD45RO+ cells into collagen gels was also seen after culture in antigenic stimuli (PPD or AMLR) but not with polyclonal activators (alpha CD3 or Con A). Double labelling showed that, within the CD4+ and CD8+ subsets, antigen-stimulated CD45RO+ T cells invaded collagen gels in higher proportions than CD45RA+ T cells. Clustering of lymphocytes with accessory cells is an essential prerequisite for locomotion and, after culture in alpha CD3, CD45RO+ lymphocytes were found preferentially in clusters with monocytes. In all of the above populations, CD45RO+ lymphocytes were larger in size. These findings suggest that, not only selective adhesion to vascular endothelium as reported earlier, but also selective locomotion recruits CD45RO+ lymphocytes into sites of inflammation. PMID:8436407

  3. The dynamics of correlated novelties

    NASA Astrophysics Data System (ADS)

    Tria, F.; Loreto, V.; Servedio, V. D. P.; Strogatz, S. H.

    2014-07-01

    Novelties are a familiar part of daily life. They are also fundamental to the evolution of biological systems, human society, and technology. By opening new possibilities, one novelty can pave the way for others in a process that Kauffman has called ``expanding the adjacent possible''. The dynamics of correlated novelties, however, have yet to be quantified empirically or modeled mathematically. Here we propose a simple mathematical model that mimics the process of exploring a physical, biological, or conceptual space that enlarges whenever a novelty occurs. The model, a generalization of Polya's urn, predicts statistical laws for the rate at which novelties happen (Heaps' law) and for the probability distribution on the space explored (Zipf's law), as well as signatures of the process by which one novelty sets the stage for another. We test these predictions on four data sets of human activity: the edit events of Wikipedia pages, the emergence of tags in annotation systems, the sequence of words in texts, and listening to new songs in online music catalogues. By quantifying the dynamics of correlated novelties, our results provide a starting point for a deeper understanding of the adjacent possible and its role in biological, cultural, and technological evolution.

  4. The dynamics of correlated novelties.

    PubMed

    Tria, F; Loreto, V; Servedio, V D P; Strogatz, S H

    2014-01-01

    Novelties are a familiar part of daily life. They are also fundamental to the evolution of biological systems, human society, and technology. By opening new possibilities, one novelty can pave the way for others in a process that Kauffman has called "expanding the adjacent possible". The dynamics of correlated novelties, however, have yet to be quantified empirically or modeled mathematically. Here we propose a simple mathematical model that mimics the process of exploring a physical, biological, or conceptual space that enlarges whenever a novelty occurs. The model, a generalization of Polya's urn, predicts statistical laws for the rate at which novelties happen (Heaps' law) and for the probability distribution on the space explored (Zipf's law), as well as signatures of the process by which one novelty sets the stage for another. We test these predictions on four data sets of human activity: the edit events of Wikipedia pages, the emergence of tags in annotation systems, the sequence of words in texts, and listening to new songs in online music catalogues. By quantifying the dynamics of correlated novelties, our results provide a starting point for a deeper understanding of the adjacent possible and its role in biological, cultural, and technological evolution. PMID:25080941

  5. Modulation by group I mGLU receptor activation and group III mGLU receptor blockade of locomotor responses induced by D1-like and D2-like receptor agonists in the nucleus accumbens.

    PubMed

    Rouillon, Christophe; Degoulet, Mickael; Chevallier, Karine; Abraini, Jacques H; David, Hélène N

    2008-03-10

    Evidence for functional motor interactions between group I and group III metabotropic glutamatergic (mGlu) receptors and dopamine neurotransmission is now clearly established [David, H.N., Abraini, J.H., 2001a. The group I metabotropic glutamate receptor antagonist S-4-CPG modulates the locomotor response produced by the activation of D1-like, but not D2-like, dopamine receptors in the rat nucleus accumbens. Eur. J. Neurosci. 15, 2157-2164, David, H.N., Abraini, J.H., 2002. Group III metabotropic glutamate receptors and D1-like and D2-like dopamine receptors interact in the rat nucleus accumbens to influence locomotor activity. Eur. J. Neurosci. 15, 869-875]. Nevertheless, whether or not and how, activation of group I and blockade of group III mGlu receptors modulate the motor responses induced by the activation of dopaminergic receptors in the NAcc still remains unknown. Answering this question needs to be assessed since functional interactions between neurotransmitters in the NAcc are well known to depend upon the level of activation of glutamatergic and/or dopaminergic receptors and because the effects of glutamatergic receptor agonists and antagonists on dopaminergic receptor-mediated locomotor responses are not always reciprocal as shown in previous studies. Our results show that activation of group I mGlu receptors by DHPG in the NAcc potentiated the locomotor response induced by intra-NAcc activation of D1-like receptors and blocked those induced by D2-like presynaptic or postsynaptic receptors. Alternatively, blockade of group III mGlu receptors by MPPG in the NAcc potentiated the locomotor responses mediated by D1-like receptors and by D2-like postsynaptic receptors and inhibited that induced by D2-like presynaptic receptors. These results compiled with previous data demonstrate that group I mGlu receptors and group III mGlu receptors can modulate the locomotor responses produced by D1-like and/or D2-like receptor agonists in a complex phasic and tonic

  6. Altered profiles of spontaneous novelty seeking, impulsive behavior, and response to D-amphetamine in rats perinatally exposed to bisphenol A.

    PubMed Central

    Adriani, Walter; Seta, Daniele Della; Dessì-Fulgheri, Francesco; Farabollini, Francesca; Laviola, Giovanni

    2003-01-01

    Bisphenol A (BPA) is an environmental estrogen with potentially averse effects on public health. We studied the long-term effects of perinatal exposure to BPA on later behavior in adult rats of both sexes. BPA or vehicle was administered orally to mother rats from mating to pups' weaning, at a concentration (0.040 mg/kg) within the range of human exposure. The offspring of both sexes were tested at adolescence (postnatal days 35-45) for novelty preference (experiment 1). After a 3-day familiarization to one side of a two-chamber apparatus, on day 4 rats were allowed to freely explore the whole apparatus. BPA-exposed females spent significantly less time than did controls in exploration of the novel side (i.e., increased neophobia), whereas no effect was found in the male group. At adulthood, the same animals were food deprived and tested for profiles of impulsive behavior (experiment 2), in operant chambers provided with two nose-poking holes (delivering either five or one food pellet). After the establishment of a baseline preference for the large reinforcer, a delay was introduced before the delivery of the five food pellets, which was progressively increased each day (10, 20, 30, 45, 60, 80, 100 sec). As expected, all animals exhibited a progressive shift toward the immediate but smaller reinforcer. A reduced level of impulsive behavior (i.e., a shift to the right in the intolerance-delay curve) was evidenced in BPA-treated rats. The frequency of inadequate responding (during the length of the delay) also provided a measure of restless behavior. Interestingly, the profile of BPA-treated males was feminized, strongly resembling that of control females. Animals were then tested (experiment 3) for the response to an amphetamine challenge (1 mg/kg, subcutaneously). The drug-induced increment activity was significantly less marked in BPA-treated male rats compared with controls. These findings provide clear indirect evidence of long-term alterations in brain

  7. The Wilderness Novelty Seeking Scale.

    PubMed

    Próchniak, Piotr

    2014-10-01

    The purpose was to present the new scale of novelty seeking in the context of wilderness. A study of the psychometric properties of the Wilderness Novelty Seeking Scale was conducted, with an exploratory and a confirmatory factor analysis being carried out and the coefficients of the scale's reliability and stability over time being tested. The convergent validity of the WNSS scale was indicated by positive correlations with sensation seeking, openness to experience, and need for cognition. The divergent validity of the WNSS scale was indicated by non-significant correlations with state-trait anxiety and depression. The correlation between the Wilderness Novelty Seeking Scale and psychological well-being was analyzed. The Wilderness Novelty Seeking Scale seems to be a reliable and valid tool. PMID:25202995

  8. An Evolutionarily Conserved Switch in Response to GABA Affects Development and Behavior of the Locomotor Circuit of Caenorhabditis elegans

    PubMed Central

    Han, Bingjie; Bellemer, Andrew; Koelle, Michael R.

    2015-01-01

    The neurotransmitter gamma-aminobutyric acid (GABA) is depolarizing in the developing vertebrate brain, but in older animals switches to hyperpolarizing and becomes the major inhibitory neurotransmitter in adults. We discovered a similar developmental switch in GABA response in Caenorhabditis elegans and have genetically analyzed its mechanism and function in a well-defined circuit. Worm GABA neurons innervate body wall muscles to control locomotion. Activation of GABAA receptors with their agonist muscimol in newly hatched first larval (L1) stage animals excites muscle contraction and thus is depolarizing. At the mid-L1 stage, as the GABAergic neurons rewire onto their mature muscle targets, muscimol shifts to relaxing muscles and thus has switched to hyperpolarizing. This muscimol response switch depends on chloride transporters in the muscles analogous to those that control GABA response in mammalian neurons: the chloride accumulator sodium-potassium-chloride-cotransporter-1 (NKCC-1) is required for the early depolarizing muscimol response, while the two chloride extruders potassium-chloride-cotransporter-2 (KCC-2) and anion-bicarbonate-transporter-1 (ABTS-1) are required for the later hyperpolarizing response. Using mutations that disrupt GABA signaling, we found that neural circuit development still proceeds to completion but with an ∼6-hr delay. Using optogenetic activation of GABAergic neurons, we found that endogenous GABAA signaling in early L1 animals, although presumably depolarizing, does not cause an excitatory response. Thus a developmental depolarizing-to-hyperpolarizing shift is an ancient conserved feature of GABA signaling, but existing theories for why this shift occurs appear inadequate to explain its function upon rigorous genetic analysis of a well-defined neural circuit. PMID:25644702

  9. An evolutionarily conserved switch in response to GABA affects development and behavior of the locomotor circuit of Caenorhabditis elegans.

    PubMed

    Han, Bingjie; Bellemer, Andrew; Koelle, Michael R

    2015-04-01

    The neurotransmitter gamma-aminobutyric acid (GABA) is depolarizing in the developing vertebrate brain, but in older animals switches to hyperpolarizing and becomes the major inhibitory neurotransmitter in adults. We discovered a similar developmental switch in GABA response in Caenorhabditis elegans and have genetically analyzed its mechanism and function in a well-defined circuit. Worm GABA neurons innervate body wall muscles to control locomotion. Activation of GABAA receptors with their agonist muscimol in newly hatched first larval (L1) stage animals excites muscle contraction and thus is depolarizing. At the mid-L1 stage, as the GABAergic neurons rewire onto their mature muscle targets, muscimol shifts to relaxing muscles and thus has switched to hyperpolarizing. This muscimol response switch depends on chloride transporters in the muscles analogous to those that control GABA response in mammalian neurons: the chloride accumulator sodium-potassium-chloride-cotransporter-1 (NKCC-1) is required for the early depolarizing muscimol response, while the two chloride extruders potassium-chloride-cotransporter-2 (KCC-2) and anion-bicarbonate-transporter-1 (ABTS-1) are required for the later hyperpolarizing response. Using mutations that disrupt GABA signaling, we found that neural circuit development still proceeds to completion but with an ∼6-hr delay. Using optogenetic activation of GABAergic neurons, we found that endogenous GABAA signaling in early L1 animals, although presumably depolarizing, does not cause an excitatory response. Thus a developmental depolarizing-to-hyperpolarizing shift is an ancient conserved feature of GABA signaling, but existing theories for why this shift occurs appear inadequate to explain its function upon rigorous genetic analysis of a well-defined neural circuit. PMID:25644702

  10. NOVELTY DETECTION UNDER CHANGING ENVIRONMENTAL CONDITIONS

    SciTech Connect

    H. SOHN; K. WORDER; C. R. FARRAR

    2001-04-01

    The primary objective of novelty detection is to examine a system's dynamic response to determine if the system significantly deviates from an initial baseline condition. In reality, the system is often subject to changing environmental and operation conditions that affect its dynamic characteristics. Such variations include changes in loading, boundary conditions, temperature, and moisture. Most damage diagnosis techniques, however, generally neglect the effects of these changing ambient conditions. Here, a novelty detection technique is developed explicitly taking into account these natural variations of the system in order to minimize false positive indications of true system changes. Auto-associative neural networks are employed to discriminate system changes of interest such as structural deterioration and damage from the natural variations of the system.

  11. Novelty, stimulus control, and operant variability

    PubMed Central

    Shahan, Timothy A.; Chase, Philip N.

    2002-01-01

    Although behavior analysis has been criticized for failure to account for response novelty, many common behavior-analytic concepts and processes (e.g., selectionism, the operant, reinforcement, and stimulus control) assume variability both in the environment and in behavior. The importance of the relation between variability and novelty, particularly for verbal behavior, is discussed, and concepts used to account for novel behavior are examined. Experimental findings also are reviewed that suggest that variability in behavior can come under discriminative control, and these findings are applied to describe novel instances of behavior that may arise during problem solving. We conclude that variations provided and selected by the terms of the three-term contingency are powerful means for understanding novel behavior. PMID:22478385

  12. Auditory stimuli enhance MDMA-conditioned reward and MDMA-induced nucleus accumbens dopamine, serotonin and locomotor responses

    PubMed Central

    Feduccia, Allison A.; Duvauchelle, Christine L.

    2016-01-01

    MDMA (3,4-methylenedioxymethamphetamine), also known as ecstasy, is a popular drug often taken in environments rich in audio and visual stimulation, such as clubs and dance parties. The present experiments were conducted to test the notion that auditory stimulation influences the rewarding effects of MDMA. In Experiment 1, a conditioned place preference (CPP) procedure was conducted in which rats received MDMA (1.5 mg/kg, s.c.) in a distinctive environment accompanied by music (65–75 dB), white noise (70 dB), or no added sound. Animals were pretreated with saline on alternating days in an alternate environment. Results revealed CPP in animals exposed to white noise during MDMA trials. For Experiment 2, rats from Experiment 1 had access to operant levers that delivered intravenous MDMA (0.5 mg/kg/inj) or saline (0.1 ml) on alternate days in the presence or absence of the same types of auditory stimuli as previously experienced. After three each of MDMA and non-reinforced (saline) sessions, animals were tested for NAcc DA and 5-HT responses to MDMA (1.5 mg/kg) or saline under the same stimulus conditions. Findings revealed that NAcc DA and 5-HT increased after an MDMA injection, and both DA and 5-HT were significantly highest in animals exposed to music during the test session. These results indicate that paired sensorial stimuli can engage the same systems activated during drug use and enhance neurochemical and behavioral responses to MDMA administration. PMID:18722516

  13. Revisiting the Novelty Effect: When Familiarity, Not Novelty, Enhances Memory

    ERIC Educational Resources Information Center

    Poppenk, J.; Kohler, S.; Moscovitch, M.

    2010-01-01

    Reports of superior memory for novel relative to familiar material have figured prominently in recent theories of memory. However, such "novelty effects" are incongruous with long-standing observations that familiar items are remembered better. In 2 experiments, we explored whether this discrepancy was explained by differences in the type of…

  14. Genetic independence of mouse measures of some aspects of novelty seeking.

    PubMed

    Kliethermes, Christopher L; Crabbe, John C

    2006-03-28

    High novelty seeking is a complex personality attribute correlated with risk for substance abuse. There are many putative mouse models of some aspects of novelty seeking, but little is known of genetic similarities among these models. To assess the genetic coherence of "novelty seeking," we compared the performance of 14 inbred strains of mice in five tests: activity in a novel environment, novel environment preference, head dipping on a hole-board, object preference, and a two-trial version of the spontaneous alternation task. Differences among strains were observed for all tasks, but performance in any given task was generally not predictive of performance in any other. To evaluate similarities among these tasks further, we selectively bred lines of mice for high or low head dipping on the hole-board. Similar to results from the inbred strain experiments, head dipping was not correlated with performance in the other measures but was genetically correlated with differences in locomotor activity. Using two approaches to estimating common genetic influences across tasks, we have found little evidence that these partial models of novelty seeking reflect the influence of common genes or measure a single, unified construct called novelty seeking. Based on the substantial influence of genetic factors, ease of implementation, and relative independence from general locomotion, head dipping on a hole-board is a good task to use in the domain of novelty seeking, but multiple tasks, including others not tested here, would be needed to capture the full genetic range of the behavioral domain. PMID:16551746

  15. Optical Correlator Performs Novelty Filtering

    NASA Technical Reports Server (NTRS)

    Liu, Duncan Tsuen-Hsi; Chao, Tien-Hsin; Cheng, Li-Jen

    1994-01-01

    Experimental real-time optical correlator performs correlation and novelty filtering in photorefractive crystal. Crystal oriented enabling cross-polarization diffraction: together with polarizing beam splitter, increases signal-to-noise ratio. Laser and optical components expand, collimate, and divide laser beam.

  16. Unraveling Effects of Novelty on Creativity

    ERIC Educational Resources Information Center

    Gillebaart, Marleen; Förster, Jens; Rotteveel, Mark; Jehle, Astrid C. M.

    2013-01-01

    Novelty is inherent to creative processes. A positive effect of novelty on creative task performance was therefore predicted. However, creativity can benefit from divergent, as well as convergent thinking. Subsequently, novelty may benefit creative performance when divergent thinking is required, but it could inhibit creative performance when…

  17. Hippocampal Y2 receptor-mediated mossy fiber plasticity is implicated in nicotine abstinence-related social anxiety-like behavior in an outbred rat model of the novelty-seeking phenotype

    PubMed Central

    Aydin, Cigdem; Oztan, Ozge; Isgor, Ceylan

    2014-01-01

    Experimentally naïve outbred rats display varying rates of locomotor reactivity in response to the mild stress of a novel environment. Namely, some display high rates (HR) whereas some display low rates (LR) of locomotor reactivity. Previous reports from our laboratory show that HRs, but not LRs, develop locomotor sensitization to a low dose nicotine challenge and exhibit increased social anxiety-like behavior following chronic intermittent nicotine training. Moreover, the hippocampus, specifically hippocampal Y2 receptor (Y2R)-mediated neuropeptide Y signaling is implicated in these nicotine-induced behavioral effects observed in HRs. The present study examines the structural substrates of the expression of locomotor sensitization to a low dose nicotine challenge and associated social anxiety-like behavior following chronic intermittent nicotine exposure during adolescence in the LRHR hippocampi. Our data showed that the expression of locomotor sensitization to the low dose nicotine challenge and the increase in social anxiety-like behavior were accompanied by an increase in mossy fiber terminal field size, as well as an increase in spinophilin mRNA levels in the hippocampus in nicotine pre-trained HRs compared to saline pre-trained controls. Furthermore, a novel, selective Y2R antagonist administered systemically during 1 wk of abstinence reversed the behavioral, molecular and neuromorphological effects observed in nicotine-exposed HRs. These results suggest that nicotine-induced neuroplasticity within the hippocampus may regulate abstinence-related negative affect in HRs, and implicate hippocampal Y2R in vulnerability to the behavioral and neuroplastic effects of nicotine in the novelty-seeking phenotype. PMID:25158103

  18. Hippocampal Y2 receptor-mediated mossy fiber plasticity is implicated in nicotine abstinence-related social anxiety-like behavior in an outbred rat model of the novelty-seeking phenotype.

    PubMed

    Aydin, Cigdem; Oztan, Ozge; Isgor, Ceylan

    2014-10-01

    Experimentally naïve outbred rats display varying rates of locomotor reactivity in response to the mild stress of a novel environment. Namely, some display high rates (HR) whereas some display low rates (LR) of locomotor reactivity. Previous reports from our laboratory show that HRs, but not LRs, develop locomotor sensitization to a low dose nicotine challenge and exhibit increased social anxiety-like behavior following chronic intermittent nicotine training. Moreover, the hippocampus, specifically hippocampal Y2 receptor (Y2R)-mediated neuropeptide Y signaling is implicated in these nicotine-induced behavioral effects observed in HRs. The present study examines the structural substrates of the expression of locomotor sensitization to a low dose nicotine challenge and associated social anxiety-like behavior following chronic intermittent nicotine exposure during adolescence in the LRHR hippocampi. Our data showed that the expression of locomotor sensitization to the low dose nicotine challenge and the increase in social anxiety-like behavior were accompanied by an increase in mossy fiber terminal field size, as well as an increase in spinophilin mRNA levels in the hippocampus in nicotine pre-trained HRs compared to saline pre-trained controls. Furthermore, a novel, selective Y2R antagonist administered systemically during 1 wk of abstinence reversed the behavioral, molecular and neuromorphological effects observed in nicotine-exposed HRs. These results suggest that nicotine-induced neuroplasticity within the hippocampus may regulate abstinence-related negative affect in HRs, and implicate hippocampal Y2R in vulnerability to the behavioral and neuroplastic effects of nicotine in the novelty-seeking phenotype. PMID:25158103

  19. The rise of novelty in ecosystems.

    PubMed

    Radeloff, Volker C; Williams, John W; Bateman, Brooke L; Burke, Kevin D; Carter, Sarah K; Childress, Evan S; Cromwell, Kara J; Gratton, Claudio; Hasley, Andrew O; Kraemer, Benjamin M; Latzka, Alexander W; Marin-Spiotta, Erika; Meine, Curt D; Munoz, Samuel E; Neeson, Thomas M; Pidgeon, Anna M; Rissman, Adena R; Rivera, Ricardo J; Szymanski, Laura M; Usinowicz, Jacob

    2015-12-01

    Rapid and ongoing change creates novelty in ecosystems everywhere, both when comparing contemporary systems to their historical baselines, and predicted future systems to the present. However, the level of novelty varies greatly among places. Here we propose a formal and quantifiable definition of abiotic and biotic novelty in ecosystems, map abiotic novelty globally, and discuss the implications of novelty for the science of ecology and for biodiversity conservation. We define novelty as the degree of dissimilarity of a system, measured in one or more dimensions relative to a reference baseline, usually defined as either the present or a time window in the past. In this conceptualization, novelty varies in degree, it is multidimensional, can be measured, and requires a temporal and spatial reference. This definition moves beyond prior categorical definitions of novel ecosystems, and does not include human agency, self-perpetuation, or irreversibility as criteria. Our global assessment of novelty was based on abiotic factors (temperature, precipitation, and nitrogen deposition) plus human population, and shows that there are already large areas with high novelty today relative to the early 20th century, and that there will even be more such areas by 2050. Interestingly, the places that are most novel are often not the places where absolute changes are largest; highlighting that novelty is inherently different from change. For the ecological sciences, highly novel ecosystems present new opportunities to test ecological theories, but also challenge the predictive ability of ecological models and their validation. For biodiversity conservation, increasing novelty presents some opportunities, but largely challenges. Conservation action is necessary along the entire continuum of novelty, by redoubling efforts to protect areas where novelty is low, identifying conservation opportunities where novelty is high, developing flexible yet strong regulations and policies, and

  20. Polyploidy and novelty: Gottlieb's legacy

    PubMed Central

    Soltis, Pamela S.; Liu, Xiaoxian; Marchant, D. Blaine; Visger, Clayton J.; Soltis, Douglas E.

    2014-01-01

    Nearly four decades ago, Roose & Gottlieb (Roose & Gottlieb 1976 Evolution 30, 818–830. (doi:10.2307/2407821)) showed that the recently derived allotetraploids Tragopogon mirus and T. miscellus combined the allozyme profiles of their diploid parents (T. dubius and T. porrifolius, and T. dubius and T. pratensis, respectively). This classic paper addressed the link between genotype and biochemical phenotype and documented enzyme additivity in allopolyploids. Perhaps more important than their model of additivity, however, was their demonstration of novelty at the biochemical level. Enzyme multiplicity—the production of novel enzyme forms in the allopolyploids—can provide an extensive array of polymorphism for a polyploid individual and may explain, for example, the expanded ranges of polyploids relative to their diploid progenitors. In this paper, we extend the concept of evolutionary novelty in allopolyploids to a range of genetic and ecological features. We observe that the dynamic nature of polyploid genomes—with alterations in gene content, gene number, gene arrangement, gene expression and transposon activity—may generate sufficient novelty that every individual in a polyploid population or species may be unique. Whereas certain combinations of these features will undoubtedly be maladaptive, some unique combinations of newly generated variation may provide tremendous evolutionary potential and adaptive capabilities. PMID:24958924

  1. Rats classified as low or high cocaine locomotor responders: A unique model involving striatal dopamine transporters that predicts cocaine addiction-like behaviors

    PubMed Central

    Yamamoto, Dorothy J.; Nelson, Anna M.; Mandt, Bruce H.; Larson, Gaynor A.; Rorabaugh, Jacki M.; Ng, Christopher M.C.; Barcomb, Kelsey M.; Richards, Toni L.; Allen, Richard M.; Zahniser, Nancy R.

    2013-01-01

    Individual differences are a hallmark of drug addiction. Here, we describe a rat model based on differential initial responsiveness to low dose cocaine. Despite similar brain cocaine levels, individual outbred Sprague-Dawley rats exhibit markedly different magnitudes of acute cocaine-induced locomotor activity and, thereby, can be classified as low or high cocaine responders (LCRs or HCRs). LCRs and HCRs differ in drug-induced, but not novelty-associated, hyperactivity. LCRs have higher basal numbers of striatal dopamine transporters (DATs) than HCRs and exhibit marginal cocaine inhibition of in vivo DAT activity and cocaine-induced increases in extracellular DA. Importantly, lower initial cocaine response predicts greater locomotor sensitization, conditioned place preference and greater motivation to self-administer cocaine following low dose acquisition. Further, outbred Long-Evans rats classified as LCRs, versus HCRs, are more sensitive to cocaine’s discriminative stimulus effects. Overall, results to date with the LCR/HCR model underscore the contribution of striatal DATs to individual differences in initial cocaine responsiveness and the value of assessing the influence of initial drug response on subsequent expression of addiction-like behaviors. PMID:23850581

  2. Rats classified as low or high cocaine locomotor responders: a unique model involving striatal dopamine transporters that predicts cocaine addiction-like behaviors.

    PubMed

    Yamamoto, Dorothy J; Nelson, Anna M; Mandt, Bruce H; Larson, Gaynor A; Rorabaugh, Jacki M; Ng, Christopher M C; Barcomb, Kelsey M; Richards, Toni L; Allen, Richard M; Zahniser, Nancy R

    2013-09-01

    Individual differences are a hallmark of drug addiction. Here, we describe a rat model based on differential initial responsiveness to low dose cocaine. Despite similar brain cocaine levels, individual outbred Sprague-Dawley rats exhibit markedly different magnitudes of acute cocaine-induced locomotor activity and, thereby, can be classified as low or high cocaine responders (LCRs or HCRs). LCRs and HCRs differ in drug-induced, but not novelty-associated, hyperactivity. LCRs have higher basal numbers of striatal dopamine transporters (DATs) than HCRs and exhibit marginal cocaine inhibition of in vivo DAT activity and cocaine-induced increases in extracellular DA. Importantly, lower initial cocaine response predicts greater locomotor sensitization, conditioned place preference and greater motivation to self-administer cocaine following low dose acquisition. Further, outbred Long-Evans rats classified as LCRs, versus HCRs, are more sensitive to cocaine's discriminative stimulus effects. Overall, results to date with the LCR/HCR model underscore the contribution of striatal DATs to individual differences in initial cocaine responsiveness and the value of assessing the influence of initial drug response on subsequent expression of addiction-like behaviors. PMID:23850581

  3. Sex differences in locomotor effects of morphine in the rat

    PubMed Central

    Craft, Rebecca M.; Clark, James L.; Hart, Stephen P.; Pinckney, Megan K.

    2007-01-01

    Sex differences in reinforcing, analgesic and other effects of opioids have been demonstrated; however, the extent to which sex differences in motoric effects of opioids contribute to apparent sex differences in their primary effects is not known. The goal of this study was to compare the effects of the prototypic mu opioid agonist morphine on locomotor activity in male vs. female rats. Saline or morphine (1-10 mg/kg) was administered s.c. to adult Sprague-Dawley rats, which were placed into a photobeam apparatus for 3-5 hr to measure activity. Modulation of morphine's effects by gonadal hormones and by handling (either during the test session or for 4 days before the test session) were examined. Morphine initially suppressed and later increased locomotor activity in both sexes relative to their saline-injected controls, but males were more sensitive than females to the initial locomotor suppressant effect of morphine. Intermittent, brief handling during the 3-hr test session blunted morphine-induced locomotor activation in both sexes. Females in proestrus were the most sensitive to morphine's locomotor-stimulant effect, with females in estrus showing the least response to morphine. Gonadectomized (GDX) males with or without testosterone were equally sensitive to morphine's effects, whereas GDX females treated with estradiol showed a blunted response to morphine's effects, similar to intact females in estrus. Brief handling on each of 4 consecutive days pre-test attenuated morphine's locomotor suppressant effect in males but had no effect in females, thereby eliminating the sex difference. These data suggest that sex differences in morphine's effects on locomotor activity can be attributed to gonadal hormones in females, and to differential stress-induced modulation of morphine's effects in males vs. females. PMID:17217999

  4. Novelty Seeking as a Phenotypic Marker of Adolescent Substance Use

    PubMed Central

    Bidwell, L Cinnamon; Knopik, Valerie S; Audrain-McGovern, Janet; Glynn, Tiffany R; Spillane, Nichea S; Ray, Lara A; Riggs, Nathaniel R; Guillot, Casey R; Pang, Raina D; Leventhal, Adam M

    2015-01-01

    Trait novelty seeking has been consistently implicated in substance use, yet the origins and mechanisms of novelty seeking in substance use proneness are unclear. We aimed to characterize novelty seeking as a phenotypic marker of substance use proneness in adolescence, a critical period for drug use experimentation. To this end, we parsed novelty seeking’s two constituent subdimensions – exploratory excitability (drive for novel experience) and impulsiveness (careless decision-making) – and explored the individual relations of these dimensions to: (1) the use of a variety of licit and illicit substances, (2) family history of substance use, and (3) subjective drug effects. Five hundred eighty five adolescents (mean age = 14.5 years) completed surveys of key variables. Results indicated that, when accounting for the covariation among exploratory excitability and impulsiveness, impulsiveness emerged as the more salient correlate of substance use and was independently associated with initiation of nearly all drug classes. Mediation analyses of the mechanisms of novelty seeking-related risk illustrated that impulsiveness mediated the association of family history of substance use with both initiation and past 30-day frequency of use. Both impulsiveness and exploratory excitability were associated with increased positive and negative subjective drug effects, and the analyses supported a significant indirect pathway from impulsiveness to a more frequent use via positive subjective effects. Although limited by a cross-sectional design, these findings suggest that impulsiveness-like aspects of the novelty seeking construct may represent a useful phenotypic marker for early substance use proneness that potentially (1) increases initiation risk, (2) has familial origins, and (3) promotes more frequent use by altering subjective drug response. PMID:26106262

  5. High-novelty-preference rats are predisposed to compulsive cocaine self-administration.

    PubMed

    Belin, David; Berson, Nadège; Balado, Eric; Piazza, Pier Vincenzo; Deroche-Gamonet, Véronique

    2011-02-01

    Sensation/novelty-seeking is amongst the best markers of cocaine addiction in humans. However, its implication in the vulnerability to cocaine addiction is still a matter of debate, as it is unclear whether this trait precedes or follows the development of addiction. Sensation/novelty-seeking trait has been identified in rats on the basis of either novelty-induced locomotor activity (high-responder (HR) trait) or novelty-induced place preference (high-novelty-preference trait (HNP)). HR and HNP traits have been associated with differential sensitivity to psychostimulants. However, it has recently been demonstrated that HR rats do not develop compulsive cocaine self-administration (SA) after protracted exposure to the drug, thereby suggesting that at least one dimension of sensation/novelty seeking in the rat is dissociable from the vulnerability to switch from controlled to compulsive cocaine SA. We therefore investigated whether HNP, as measured as the propensity to choose a new environment in a free choice procedure, as opposed to novelty-induced locomotor activity, predicts the vulnerability to, and the severity of, addiction-like behavior for cocaine. For this, we identified HR/LR rats and HNP/LNP rats before any exposure to cocaine. After 60 days of cocaine SA, each rat was given an addiction score based on three addiction-like behaviors (persistence of responding when the drug is signaled as not available, high breakpoint under progressive ratio schedule and resistance to punishment) that resemble the clinical features of drug addiction, namely inability to refrain from drug seeking, high motivation for the drug and compulsive drug use despite adverse consequences. We show that, as opposed to HR rats, HNP rats represent a sub-population predisposed to compulsive cocaine intake, displaying higher addiction scores than LNP rats. This study thereby provides new insights into the factors predisposing to cocaine addiction, supporting the hypothesis that addiction

  6. A dose-response study of separate and combined effects of the serotonin agonist 8-OH-DPAT and the dopamine agonist quinpirole on locomotor sensitization, cross-sensitization, and conditioned activity.

    PubMed

    Johnson, Eric F; Szechtman, Henry

    2016-08-01

    Chronic treatment with the dopamine D2/D3 agonist, quinpirole, or the serotonin 1A agonist, 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT), induces behavioral sensitization. It is not known whether both drugs produce sensitization through a shared mechanism. Here, we examine whether quinpirole and 8-OH-DPAT show cross-sensitization and impact sensitization, as would be expected from shared mechanisms. Male rats (N=208) were assigned randomly to 16 groups formed by crossing four doses of quinpirole (0, 0.03125, 0.0625, or 0.125 mg/kg) with four doses of 8-OH-DPAT (0, 0.03125, 0.625, or 0.125 mg/kg). After a course of 10 drug treatments administered twice per week in locomotor activity chambers, all groups were challenged on separate tests with quinpirole (0.1 mg/kg), 8-OH-DPAT (0.1 mg/kg), or saline, and locomotor activity was evaluated. Challenge tests with quinpirole and 8-OHDPAT showed no cross-sensitization between the drugs. Chronic quinpirole (0.125 mg/kg) administration induced a sensitized quinpirole response that was attenuated dose-dependently by chronic 8-OH-DPAT cotreatment. Cotreatment with quinpirole (0.0625 mg/kg) and 8-OH-DPAT (all doses) induced quinpirole sensitization. Chronic 8-OH-DPAT (0.125 mg/kg) induced a sensitized 8-OHDPAT response that was prevented by chronic cotreatment with the lowest but not the highest dose of quinpirole. Cotreatment with 8-OHDPAT (0.0625) and quinpirole (0.125 mg/kg) induced sensitization to 8-OH-DPAT. The saline challenge test showed elevated locomotor activity in chronic quinpirole (0.125 mg/kg) and 8-OHDPAT (0.0625, 0.125 mg/kg) alone groups, and in seven of nine cotreated groups. The absence of cross-sensitization suggests separate mechanisms of sensitization to quinpirole and 8-OH-DPAT. Cotreatment effects suggest that induction of sensitization can be modulated by serotonin 1A and D2/D3 activity. PMID:26871406

  7. Role of Partner Novelty in Sexual Functioning: A Review.

    PubMed

    Morton, Heather; Gorzalka, Boris B

    2015-01-01

    This review investigates whether sexual desire and arousal decline in response to partner familiarity, increase in response to partner novelty, and show differential responding in men and women. These questions were considered through the perspective of two leading evolutionary theories regarding human mating strategies: sexual strategies theory and attachment fertility theory. The hypotheses emerging from these theories were evaluated through a critical analysis of several areas of research including habituation of arousal to erotic stimuli, preferences regarding number of sexual partners, the effect of long-term monogamous relationships on sexual arousal and desire, and prevalence and risk factors associated with extradyadic behavior. The current literature best supports the predictions made by sexual strategies theory in that sexual functioning has evolved to promote short-term mating. Sexual arousal and desire appear to decrease in response to partner familiarity and increase in response to partner novelty in men and women. Evidence to date suggests this effect may be greater in men. PMID:25222339

  8. Hippocampal Networks Habituate as Novelty Accumulates

    ERIC Educational Resources Information Center

    Murty, Vishnu P.; Ballard, Ian C.; Macduffie, Katherine E.; Krebs, Ruth M.; Adcock, R. Alison

    2013-01-01

    Novelty detection, a critical computation within the medial temporal lobe (MTL) memory system, necessarily depends on prior experience. The current study used functional magnetic resonance imaging (fMRI) in humans to investigate dynamic changes in MTL activation and functional connectivity as experience with novelty accumulates. fMRI data were…

  9. Novelty Seeking in Adulthood: Increases Accompany Decline

    ERIC Educational Resources Information Center

    Reio, Thomas G., Jr.; Choi, Namok

    2004-01-01

    Using stereotypes, researchers have predicted that novelty seeking declines in adulthood. Through this cross-sectional study, the authors revealed that only the external sensational type of novelty seeking declined, whereas the internal sensational and internal and external cognitive types remained stable or increased. A population of 233 adults…

  10. Effects of Sodium Butyrate on Methamphetamine-Sensitized Locomotor Activity

    PubMed Central

    Harkness, John H.; Hitzemann, Robert J.; Edmunds, Stephanie; Phillips, Tamara J.

    2012-01-01

    Neuroadaptations associated with behavioral sensitization induced by repeated exposure to methamphetamine (MA) appear to be involved in compulsive drug pursuit and use. Increased histone acetylation, an epigenetic effect resulting in altered gene expression, may promote sensitized responses to psychostimulants. The role of histone acetylation in the expression and acquisition of MA-induced locomotor sensitization was examined by measuring the effect of histone deacetylase inhibition by sodium butyrate (NaB). For the effect on expression, vehicle or NaB (630 mg/kg, intraperitoneally) was administered 30 min prior to MA challenge in mice treated repeatedly with MA (10 days of 2 mg/kg MA) or saline (10 days), and then locomotor response to MA challenge was measured. NaB treatment increased the locomotor response to MA in both acutely MA treated and sensitized animals. For acquisition, NaB was administered 30 min prior to each MA exposure (10 days of 1 or 2 mg/kg), but not prior to the MA challenge test. Treatment with NaB during the sensitization acquisition period significantly increased locomotor activation by MA in sensitized mice only. NaB alone did not significantly alter locomotor activity. Acute NaB or MA, but not the combination, appeared to increase striatal acetylation at histone H4. Repeated treatment with MA, but not NaB or MA plus NaB, increased striatal acetylation at histone H3. Although increased histone acetylation may alter the expression of genes involved in acute locomotor response to MA and in the acquisition of MA-induced sensitization, results for acetylation at H3 and H4 showed little correspondence with behavior. PMID:23137698

  11. NOVELTY PREFERENCE IN PATIENTS WITH DEVELOPMENTAL AMNESIA

    PubMed Central

    Munoz, M.; Chadwick, M.; Perez-Hernandez, E; Vargha-Khadem, F.; Mishkin, M.

    2010-01-01

    To re-examine whether or not selective hippocampal damage reduces novelty preference in visual paired comparison (VPC), we presented two different versions of the task to a group of patients with developmental amnesia (DA), each of whom sustained this form of pathology early in life. Compared with normal control participants, the DA group showed a delay-dependent reduction in novelty preference on one version of the task and an overall reduction on both versions combined. Because VPC is widely considered to be a measure of incidental recognition, the results appear to support the view that the hippocampus contributes to recognition memory. A difficulty for this conclusion, however, is that according to one current view the hippocampal contribution to recognition is limited to task conditions that encourage recollection of an item in some associated context, and according to another current view, to recognition of an item with the high confidence judgment that reflects a strong memory. By contrast, VPC, throughout which the participant remains entirely uninstructed other than to view the stimuli, would seem to lack such task conditions and so would likely lead to recognition based on familiarity rather than recollection or, alternatively, weak memories rather than strong. However, before concluding that the VPC impairment therefore contradicts both current views regarding the role of the hippocampus in recognition memory, two possibilities that would resolve this issue need to be investigated. One is that some variable in VPC, such as the extended period of stimulus encoding during familiarization, overrides its incidental nature, and, because this condition promotes either recollection- or strength-based recognition, renders the task hippocampal-dependent. The other possibility is that VPC, rather than providing a measure of incidental recognition, actually assesses an implicit, information-gathering process modulated by habituation, for which the hippocampus is

  12. Novelty preference in patients with developmental amnesia.

    PubMed

    Munoz, M; Chadwick, M; Perez-Hernandez, E; Vargha-Khadem, F; Mishkin, M

    2011-12-01

    To re-examine whether or not selective hippocampal damage reduces novelty preference in visual paired comparison (VPC), we presented two different versions of the task to a group of patients with developmental amnesia (DA), each of whom sustained this form of pathology early in life. Compared with normal control participants, the DA group showed a delay-dependent reduction in novelty preference on one version of the task and an overall reduction on both versions combined. Because VPC is widely considered to be a measure of incidental recognition, the results appear to support the view that the hippocampus contributes to recognition memory. A difficulty for this conclusion, however, is that according to one current view the hippocampal contribution to recognition is limited to task conditions that encourage recollection of an item in some associated context, and according to another current view, to recognition of an item with the high confidence judgment that reflects a strong memory. By contrast, VPC, throughout which the participant remains entirely uninstructed other than to view the stimuli, would seem to lack such task conditions and so would likely lead to recognition based on familiarity rather than recollection or, alternatively, weak memories rather than strong. However, before concluding that the VPC impairment therefore contradicts both current views regarding the role of the hippocampus in recognition memory, two possibilities that would resolve this issue need to be investigated. One is that some variable in VPC, such as the extended period of stimulus encoding during familiarization, overrides its incidental nature, and, because this condition promotes either recollection- or strength-based recognition, renders the task hippocampal-dependent. The other possibility is that VPC, rather than providing a measure of incidental recognition, actually assesses an implicit, information-gathering process modulated by habituation, for which the hippocampus is

  13. Contextual interaction between novelty and reward processing within the mesolimbic system

    PubMed Central

    Bunzeck, Nico; Doeller, Christian F; Dolan, Ray J; Duzel, Emrah

    2012-01-01

    Medial temporal lobe (MTL) dependent long-term memory for novel events is modulated by a circuitry that also responds to reward and includes the ventral striatum, dopaminergic midbrain, and medial orbitofrontal cortex (mOFC). This common neural network may reflect a functional link between novelty and reward whereby novelty motivates exploration in the search for rewards; a link also termed novelty “exploration bonus.” We used fMRI in a scene encoding paradigm to investigate the interaction between novelty and reward with a focus on neural signals akin to an exploration bonus. As expected, reward related long-term memory for the scenes (after 24 hours) strongly correlated with activity of MTL, ventral striatum, and substantia nigra/ventral tegmental area (SN/VTA). Furthermore, the hippocampus showed a main effect of novelty, the striatum showed a main effect of reward, and the mOFC signalled both novelty and reward. An interaction between novelty and reward akin to an exploration bonus was found in the hippocampus. These data suggest that MTL novelty signals are interpreted in terms of their reward-predicting properties in the mOFC, which biases striatal reward responses. The striatum together with the SN/VTA then regulates MTL-dependent long-term memory formation and contextual exploration bonus signals in the hippocampus. Hum Brain Mapp, 2011. © 2011 Wiley-Liss, Inc. PMID:21520353

  14. Quaternary naltrexone reverses radiogenic and morphine-induced locomotor hyperactivity

    SciTech Connect

    Mickley, G.A.; Stevens, K.E.; Galbraith, J.A.; White, G.A.; Gibbs, G.L.

    1984-04-01

    The present study attempted to determine the relative role of the peripheral and central nervous system in the production of morphine-induced or radiation-induced locomotor hyperactivity of the mouse. Toward this end, we used a quaternary derivative of an opiate antagonist (naltrexone methobromide), which presumably does not cross the blood-brain barrier. Quaternary naltrexone was used to challenge the stereotypic locomotor response observed in these mice after either an i.p. injection of morphine or exposure to 1500 rads /sup 60/Co. The quaternary derivative of naltrexone reversed the locomotor hyperactivity normally observed in the C57BL/6J mouse after an injection of morphine. It also significantly attenuated radiation-induced locomotion. The data reported here support the hypothesis of endorphin involvement in radiation-induced and radiogenic behaviors. However, these conclusions are contingent upon further research which more fully evaluates naltrexone methobromide's capacity to cross the blood-brain barrier.

  15. Homology, homoplasy, novelty, and behavior.

    PubMed

    Hall, Brian K

    2013-01-01

    Richard Owen coined the modern definition of homology in 1843. Owen's conception of homology was pre-evolutionary, nontransformative (homology maintained basic plans or archetypes), and applied to the fully formed structures of animals. I sketch out the transition to an evolutionary approach to homology in which all classes of similarity are interpreted against the single branching tree of life, and outline the evidence for the application of homology across all levels and features of the biological hierarchy, including behavior. Owen contrasted homology with analogy. While this is not incorrect it is a pre-evolutionary contrast. Lankester [Lankester [1870] Journal of Natural History, 6 (31), 34-43] proposed homoplasy as the class of homology applicable to features formed by independent evolution. Today we identify homology, convergence, parallelism, and novelties as patterns of evolutionary change. A central issue in homology [Owen [1843] Lectures on comparative anatomy and physiology of the invertebrate animals, delivered at the Royal College of Surgeons in 1843. London: Longman, Brown, Green & Longmans] has been whether homology of features-the "same" portion of the brain in different species, for example-depends upon those features sharing common developmental pathways. Owen did not require this criterion, although he observed that homologues often do share developmental pathways (and we now know, often share gene pathways). A similar situation has been explored in the study of behavior, especially whether behaviors must share a common structural, developmental, neural, or genetic basis to be classified as homologous. However, and importantly, development and genes evolve. As shown with both theory and examples, morphological and behavioral features of the phenotype can be homologized as structural or behavioral homologues, respectively, even when their developmental or genetic bases differ (are not homologous). PMID:22711423

  16. Novelty, coherence, and Mendeleev's periodic table.

    PubMed

    Schindler, Samuel

    2014-03-01

    Predictivism is the view that successful predictions of "novel" evidence carry more confirmational weight than accommodations of already known evidence. Novelty, in this context, has traditionally been conceived of as temporal novelty. However temporal predictivism has been criticized for lacking a rationale: why should the time order of theory and evidence matter? Instead, it has been proposed, novelty should be construed in terms of use-novelty, according to which evidence is novel if it was not used in the construction of a theory. Only if evidence is use-novel can it fully support the theory entailing it. As I point out in this paper, the writings of the most influential proponent of use-novelty contain a weaker and a stronger version of use-novelty. However both versions, I argue, are problematic. With regard to the appraisal of Mendeleev' periodic table, the most contentious historical case in the predictivism debate, I argue that temporal predictivism is indeed supported, although in ways not previously appreciated. On the basis of this case, I argue for a form of so-called symptomatic predictivism according to which temporally novel predictions carry more confirmational weight only insofar as they reveal the theory's presumed coherence of facts as real. PMID:24984451

  17. Functional redundancy of ventral spinal locomotor pathways.

    PubMed

    Loy, David N; Magnuson, David S K; Zhang, Y Ping; Onifer, Stephen M; Mills, Michael D; Cao, Qi-lin; Darnall, Jessica B; Fajardo, Lily C; Burke, Darlene A; Whittemore, Scott R

    2002-01-01

    Identification of long tracts responsible for the initiation of spontaneous locomotion is critical for spinal cord injury (SCI) repair strategies. Pathways derived from the mesencephalic locomotor region and pontomedullary medial reticular formation responsible for fictive locomotion in decerebrate preparations project to the thoracolumbar levels of the spinal cord via reticulospinal axons in the ventrolateral funiculus (VLF). However, white matter regions critical for spontaneous over-ground locomotion remain unclear because cats, monkeys, and humans display varying degrees of locomotor recovery after ventral SCIs. We studied the contributions of myelinated tracts in the VLF and ventral columns (VC) to spontaneous over-ground locomotion in the adult rat using demyelinating lesions. Animals received ethidium bromide plus photon irradiation producing discrete demyelinating lesions sufficient to stop axonal conduction in the VLF, VC, VLF-VC, or complete ventral white matter (CV). Behavior [open-field Basso, Beattie, and Bresnahan (BBB) scores and grid walking] and transcranial magnetic motor-evoked potentials (tcMMEP) were studied at 1, 2, and 4 weeks after lesion. VLF lesions resulted in complete loss or severe attenuation of tcMMEPs, with mean BBB scores of 18.0, and no grid walking deficits. VC lesions produced behavior similar to VLF-lesioned animals but did not significantly affect tcMMEPs. VC-VLF and CV lesions resulted in complete loss of tcMMEP signals with mean BBB scores of 12.7 and 6.5, respectively. Our data support a diffuse arrangement of axons within the ventral white matter that may comprise a system of multiple descending pathways subserving spontaneous over-ground locomotion in the intact animal. PMID:11756515

  18. Modulation of locomotor activation by the rostromedial tegmental nucleus.

    PubMed

    Lavezzi, Heather N; Parsley, Kenneth P; Zahm, Daniel S

    2015-02-01

    The rostromedial tegmental nucleus (RMTg) is a strong inhibitor of dopamine neurons in the ventral tegmental area (VTA) reported to influence neurobiological and behavioral responses to reward omission, aversive and fear-eliciting stimuli, and certain drugs of abuse. Insofar as previous studies implicate ventral mesencephalic dopamine neurons as an essential component of locomotor activation, we hypothesized that the RMTg also should modulate locomotion activation. We observed that bilateral infusions into the RMTg of the gamma-aminobutyric acid A (GABAA) agonist, muscimol, indeed activate locomotion. Alternatively, bilateral RMTg infusions of the GABAA receptor antagonist, bicuculline, suppress robust activations of locomotion elicited in two distinct ways: (1) by disinhibitory stimulation of neurons in the lateral preoptic area and (2) by return of rats to an environment previously paired with amphetamine administration. The possibility that suppressive locomotor effects of RMTg bicuculline infusions were due to unintended spread of drug to the nearby VTA was falsified by a control experiment showing that bilateral infusions of bicuculline into the VTA produce activation rather than suppression of locomotion. These results objectively implicate the RMTg in the regulation of locomotor activation. The effect is important because much evidence reported in the literature suggests that locomotor activation can be an involuntary behavioral expression of expectation and/or want without which the willingness to execute adaptive behaviors is impaired. PMID:25164249

  19. Locomotor Expertise Predicts Infants' Perseverative Errors

    ERIC Educational Resources Information Center

    Berger, Sarah E.

    2010-01-01

    This research examined the development of inhibition in a locomotor context. In a within-subjects design, infants received high- and low-demand locomotor A-not-B tasks. In Experiment 1, walking 13-month-old infants followed an indirect path to a goal. In a control condition, infants took a direct route. In Experiment 2, crawling and walking…

  20. AMPHETAMINE-, SCOPOLAMINE-, AND CAFFEINE-INDUCED LOCOMOTOR ACTIVITY FOLLOWING 6-HYDROXYDOPAMINE LESIONS OF THE MESOLIMBIC DOPAMINE SYSTEM

    EPA Science Inventory

    As previously reported, 6-hydroxydopamine (6-OHDA) lesions to the region of the nucleus accumbens blocked the locomotor activation induced by low doses of d-amphetamine, and produced a supersensitive locomotor response to the dopamine (DA) agonist, apomorphine. This same lesion, ...

  1. Locomotor adaptation to a soleus EMG-controlled antagonistic exoskeleton.

    PubMed

    Gordon, Keith E; Kinnaird, Catherine R; Ferris, Daniel P

    2013-04-01

    Locomotor adaptation in humans is not well understood. To provide insight into the neural reorganization that occurs following a significant disruption to one's learned neuromuscular map relating a given motor command to its resulting muscular action, we tied the mechanical action of a robotic exoskeleton to the electromyography (EMG) profile of the soleus muscle during walking. The powered exoskeleton produced an ankle dorsiflexion torque proportional to soleus muscle recruitment thus limiting the soleus' plantar flexion torque capability. We hypothesized that neurologically intact subjects would alter muscle activation patterns in response to the antagonistic exoskeleton by decreasing soleus recruitment. Subjects practiced walking with the exoskeleton for two 30-min sessions. The initial response to the perturbation was to "fight" the resistive exoskeleton by increasing soleus activation. By the end of training, subjects had significantly reduced soleus recruitment resulting in a gait pattern with almost no ankle push-off. In addition, there was a trend for subjects to reduce gastrocnemius recruitment in proportion to the soleus even though only the soleus EMG was used to control the exoskeleton. The results from this study demonstrate the ability of the nervous system to recalibrate locomotor output in response to substantial changes in the mechanical output of the soleus muscle and associated sensory feedback. This study provides further evidence that the human locomotor system of intact individuals is highly flexible and able to adapt to achieve effective locomotion in response to a broad range of neuromuscular perturbations. PMID:23307949

  2. Integrated Locomotor Function Tests for Countermeasure Evaluation

    NASA Technical Reports Server (NTRS)

    Bloomberg, J. J.; Mulavara, A. P.; Peters, B. T.; Cohen, H. S.; Landsness, E. C.; Black, F. O.

    2005-01-01

    Following spaceflight crewmembers experience locomotor dysfunction due to inflight adaptive alterations in sensorimotor function. Countermeasures designed to mitigate these postflight gait alterations need to be assessed with a new generation of tests that evaluate the interaction of various sensorimotor sub-systems central to locomotor control. The goal of the present study was to develop new functional tests of locomotor control that could be used to test the efficacy of countermeasures. These tests were designed to simultaneously examine the function of multiple sensorimotor systems underlying the control of locomotion and be operationally relevant to the astronaut population. Traditionally, gaze stabilization has been studied almost exclusively in seated subjects performing target acquisition tasks requiring only the involvement of coordinated eye-head movements. However, activities like walking involve full-body movement and require coordination between lower limbs and the eye-head-trunk complex to achieve stabilized gaze during locomotion. Therefore the first goal of this study was to determine how the multiple, interdependent, full-body sensorimotor gaze stabilization subsystems are functionally coordinated during locomotion. In an earlier study we investigated how alteration in gaze tasking changes full-body locomotor control strategies. Subjects walked on a treadmill and either focused on a central point target or read numeral characters. We measured: temporal parameters of gait, full body sagittal plane segmental kinematics of the head, trunk, thigh, shank and foot, accelerations along the vertical axis at the head and the shank, and the vertical forces acting on the support surface. In comparison to the point target fixation condition, the results of the number reading task showed that compensatory head pitch movements increased, peak head acceleration was reduced and knee flexion at heel-strike was increased. In a more recent study we investigated the

  3. Acute restraint stress and corticosterone transiently disrupts novelty preference in an object recognition task.

    PubMed

    Vargas-López, Viviana; Torres-Berrio, Angélica; González-Martínez, Lina; Múnera, Alejandro; Lamprea, Marisol R

    2015-09-15

    The object recognition task is a procedure based on rodents' natural tendency to explore novel objects which is frequently used for memory testing. However, in some instances novelty preference is replaced by familiarity preference, raising questions regarding the validity of novelty preference as a pure recognition memory index. Acute stress- and corticosterone administration-induced novel object preference disruption has been frequently interpreted as memory impairment; however, it is still not clear whether such effect can be actually attributed to either mnemonic disruption or altered novelty seeking. Seventy-five adult male Wistar rats were trained in an object recognition task and subjected to either acute stress or corticosterone administration to evaluate the effect of stress or corticosterone on an object recognition task. Acute stress was induced by restraining movement for 1 or 4h, ending 30 min before the sample trial. Corticosterone was injected intraperitoneally 10 min before the test trial which was performed either 1 or 24h after the sample trial. Four-hour, but not 1-h, stress induced familiar object preference during the test trial performed 1h after the sample trial; however, acute stress had no effects on the test when performed 24h after sample trial. Systemic administration of corticosterone before the test trial performed either 1 or 24h after the sample trial also resulted in familiar object preference. However, neither acute stress nor corticosterone induced changes in locomotor behaviour. Taken together, such results suggested that acute stress probably does not induce memory retrieval impairment but, instead, induces an emotional arousing state which motivates novelty avoidance. PMID:25986403

  4. Lipidomics and H218O labeling techniques reveal increased remodeling of DHA-containing membrane phospholipids associated with abnormal locomotor responses in α-tocopherol deficient zebrafish (danio rerio) embryos

    PubMed Central

    McDougall, Melissa Q.; Choi, Jaewoo; Stevens, Jan F.; Truong, Lisa; Tanguay, Robert L.; Traber, Maret G.

    2016-01-01

    We hypothesized that vitamin E (α-tocopherol) is required by the developing embryonic brain to prevent depletion of highly polyunsaturated fatty acids, especially docosahexaenoic acid (DHA, 22:6), the loss of which we predicted would underlie abnormal morphological and behavioral outcomes. Therefore, we fed adult 5D zebrafish (Danio rerio) defined diets without (E−) or with added α-tocopherol (E+, 500 mg RRR-α-tocopheryl acetate/kg diet) for a minimum of 80 days, and then spawned them to obtain E− and E+ embryos. The E− compared with E+ embryos were 82% less responsive (p<0.01) to a light/dark stimulus at 96 h post-fertilization (hpf), demonstrating impaired locomotor behavior, even in the absence of gross morphological defects. Evaluation of phospholipid (PL) and lysophospholipid (lyso-PL) composition using untargeted lipidomics in E− compared with E+ embryos at 24, 48, 72, and 120 hpf showed that four PLs and three lyso-PLs containing docosahexaenoic acid (DHA), including lysophosphatidylcholine (LPC 22:6, required for transport of DHA into the brain, p<0.001), were at lower concentrations in E− at all time-points. Additionally, H218O labeling experiments revealed enhanced turnover of LPC 22:6 (p<0.001) and three other DHA-containing PLs in the E− compared with the E+ embryos, suggesting that increased membrane remodeling is a result of PL depletion. Together, these data indicate that α-tocopherol deficiency in the zebrafish embryo causes the specific depletion and increased turnover of DHA-containing PL and lyso-PLs, which may compromise DHA delivery to the brain and thereby contribute to the functional impairments observed in E− embryos. PMID:26774753

  5. Lipidomics and H2(18)O labeling techniques reveal increased remodeling of DHA-containing membrane phospholipids associated with abnormal locomotor responses in α-tocopherol deficient zebrafish (danio rerio) embryos.

    PubMed

    McDougall, Melissa Q; Choi, Jaewoo; Stevens, Jan F; Truong, Lisa; Tanguay, Robert L; Traber, Maret G

    2016-08-01

    We hypothesized that vitamin E (α-tocopherol) is required by the developing embryonic brain to prevent depletion of highly polyunsaturated fatty acids, especially docosahexaenoic acid (DHA, 22:6), the loss of which we predicted would underlie abnormal morphological and behavioral outcomes. Therefore, we fed adult 5D zebrafish (Danio rerio) defined diets without (E-) or with added α-tocopherol (E+, 500mg RRR-α-tocopheryl acetate/kg diet) for a minimum of 80 days, and then spawned them to obtain E- and E+ embryos. The E- compared with E+ embryos were 82% less responsive (p<0.01) to a light/dark stimulus at 96h post-fertilization (hpf), demonstrating impaired locomotor behavior, even in the absence of gross morphological defects. Evaluation of phospholipid (PL) and lysophospholipid (lyso-PL) composition using untargeted lipidomics in E- compared with E+ embryos at 24, 48, 72, and 120hpf showed that four PLs and three lyso-PLs containing docosahexaenoic acid (DHA), including lysophosphatidylcholine (LPC 22:6, required for transport of DHA into the brain, p<0.001), were at lower concentrations in E- at all time-points. Additionally, H2(18)O labeling experiments revealed enhanced turnover of LPC 22:6 (p<0.001) and three other DHA-containing PLs in the E- compared with the E+ embryos, suggesting that increased membrane remodeling is a result of PL depletion. Together, these data indicate that α-tocopherol deficiency in the zebrafish embryo causes the specific depletion and increased turnover of DHA-containing PL and lyso-PLs, which may compromise DHA delivery to the brain and thereby contribute to the functional impairments observed in E- embryos. PMID:26774753

  6. MDMA (ecstasy) modulates locomotor and prefrontal cortex sensory evoked activity.

    PubMed

    Atkins, Kristal; Burks, Tilithia; Swann, Alan C; Dafny, Nachum

    2009-12-11

    Ingestion of 3, 4-methylenedioxymethamphetamine (MDMA) leads to heightened response to sensory stimulation; thus, MDMA is referred to as "ecstasy" because it produces pleasurable enhancement of such sensation. There have been no electrophysiological studies that report the consequences of MDMA on sensory input. The present study was initiated to study the effects of acute and chronic MDMA on locomotor activity and sensory evoked field potential from freely behaving rats previously implanted with permanent electrodes in the prefrontal cortex (PFC). The main findings of this study are that: (1) acute MDMA augments locomotor behavior and attenuates the incoming sensory input, (2) chronic treatment of MDMA elicits behavioral sensitization, (3) chronic administration of MDMA results in attenuation of the baseline activity of the sensory evoked field potential, and (4) administration of rechallenge MDMA result in enhancement of the PFC sensory evoked field potential. PMID:19769950

  7. Bovine growth hormone transgenic mice display alterations in locomotor activity and brain monoamine neurochemistry.

    PubMed

    Söderpalm, B; Ericson, M; Bohlooly, M; Engel, J A; Törnell, J

    1999-12-01

    Recent clinical and experimental data indicate a role for GH in mechanisms related to anhedonia/hedonia, psychic energy, and reward. In the present study we have investigated whether bovine GH (bGH) transgenic mice and nontransgenic controls differ in spontaneous locomotor activity, a behavioral response related to brain dopamine (DA) and reward mechanisms, as well as in locomotor activity response to drugs of abuse known to interfere with brain DA systems. The animals were tested for locomotor activity once a week for 4 weeks. When first exposed to the test apparatus, bGH transgenic animals displayed significantly more locomotor activity than controls during the entire registration period (1 h). One week later, after acute pretreatment with saline, the two groups did not differ in locomotor activity, whereas at the third test occasion, bGH mice were significantly more stimulated by d-amphetamine (1 mg/kg, ip) than controls. At the fourth test, a tendency for a larger locomotor stimulatory effect of ethanol (2.5 g/kg, ip) was observed in bGH transgenic mice. bGH mice displayed increased tissue levels of serotonin and 5-hydroxyindoleacetic acid in several brain regions, decreased DA levels in the brain stem, and decreased levels of the DA metabolite 3,4-dihydroxyphenylacetic acid in the mesencephalon and diencephalon, compared with controls. In conclusion, bGH mice display more spontaneous locomotor activity than nontransgenic controls in a novel environment and possibly also a disturbed habituation process. The finding that bGH mice were also more sensitive to d-amphetamine-induced locomotor activity may suggest that the behavioral differences observed are related to differences in brain DA systems, indicating a hyperresponsiveness of these systems in bGH transgenic mice. These findings may constitute a neurochemical basis for the reported psychic effects of GH in humans. PMID:10579325

  8. Novelty Detection in and Between Different Modalities

    SciTech Connect

    Veflingstad, Henning; Yildirim, Sule

    2008-01-21

    Our general aim is to reflect the advances in artificial intelligence and cognitive science fields to space exploration studies such that next generation space rovers can benefit from these advances. We believe next generation space rovers can benefit from the studies related to employing conceptual representations in generating structured thought. This way, rovers need not be equipped with all necessary steps of an action plan to execute in space exploration but they can autonomously form representations of their world and reason on them to make intelligent decision. As part of this approach, autonomous novelty detection is an important feature of next generation space rovers. This feature allows a rover to make further decisions about exploring a rock sample more closely or not and on its own. This way, a rover will use less of its time for communication between the earth and itself and more of its time for achieving its assigned tasks in space. In this paper, we propose an artificial neural network based novelty detection mechanism that next generation space rovers can employ as part of their intelligence. We also present an implementation of such a mechanism and present its reliability in detecting novelty.

  9. Novelty Detection in and Between Different Modalities

    NASA Astrophysics Data System (ADS)

    Veflingstad, Henning; Yildirim, Sule

    2008-01-01

    Our general aim is to reflect the advances in artificial intelligence and cognitive science fields to space exploration studies such that next generation space rovers can benefit from these advances. We believe next generation space rovers can benefit from the studies related to employing conceptual representations in generating structured thought. This way, rovers need not be equipped with all necessary steps of an action plan to execute in space exploration but they can autonomously form representations of their world and reason on them to make intelligent decision. As part of this approach, autonomous novelty detection is an important feature of next generation space rovers. This feature allows a rover to make further decisions about exploring a rock sample more closely or not and on its own. This way, a rover will use less of its time for communication between the earth and itself and more of its time for achieving its assigned tasks in space. In this paper, we propose an artificial neural network based novelty detection mechanism that next generation space rovers can employ as part of their intelligence. We also present an implementation of such a mechanism and present its reliability in detecting novelty.

  10. Models of neural novelty detectors, with similarities to cerebral cortex.

    PubMed

    Salu, Y

    1988-01-01

    A novelty detector is a functional unit, that indicates whether an incoming stimulus is familiar or novel. Novelty detection is prevalent in the central nervous system (CNS), and is involved in various activities. Its basic characteristics are discussed first. Then, models of neural novelty detectors are described, and tested and evaluated in simulations. The simulations have shown that one novelty detector, the bi-compartmental, simulates very closely the behavior of neural novelty detectors. This model is constructed in a way that resembles the observed architecture and function of area 17, and similar regions in the cortex. The first step in novelty detection is data retrieval. The proposed novelty detectors can utilize various compatible modes of data storage and retrieval, and one of those has been utilized in the simulations. PMID:3355886

  11. Programming social, cognitive, and neuroendocrine development by early exposure to novelty

    PubMed Central

    Tang, Akaysha C.; Akers, Katherine G.; Reeb, Bethany C.; Romeo, Russell D.; McEwen, Bruce S.

    2006-01-01

    Mildly stressful early life experiences can potentially impact a broad range of social, cognitive, and physiological functions in humans, nonhuman primates, and rodents. Recent rodent studies favor a maternal-mediation hypothesis that considers maternal-care differences induced by neonatal stimulation as the cause of individual differences in offspring development. Using neonatal novelty exposure, a neonatal stimulation paradigm that dissociates maternal individual differences from a direct stimulation effect on the offspring, we investigated the effect of early exposures to novelty on a diverse range of psychological functions using several assessment paradigms. Pups that received brief neonatal novelty exposures away from the home environment showed enhancement in spatial working memory, social competition, and corticosterone response to surprise during adulthood compared with their home-staying siblings. These functional enhancements in novelty-exposed rats occurred despite evidence that maternal care was directed preferentially toward home-staying instead of novelty-exposed pups, indicating that greater maternal care is neither necessary nor sufficient for these early stimulation-induced functional enhancements. We suggest a unifying maternal-modulation hypothesis, which distinguishes itself from the maternal-mediation hypothesis in that (i) neonatal stimulation can have direct effects on pups, cumulatively leading to long-term improvement in adult offspring; and (ii) maternal behavior can attenuate or potentiate these effects, thereby decreasing or increasing this long-term functional improvement. PMID:17030787

  12. Apathy, Novelty Processing, and the P3 Potential in Parkinson’s Disease

    PubMed Central

    Kaufman, David A. S.; Bowers, Dawn; Okun, Michael S.; Van Patten, Ryan; Perlstein, William M.

    2016-01-01

    Parkinson’s disease (PD) is characterized by deficits in goal-directed behavior as well as mood and motivational symptoms, including apathy, depression, and anxiety. The present study investigated novelty processing in PD, using event-related potentials (ERPs) to characterize electrophysiological reflections of visual novelty processing. Since apathy has been associated with decreased novelty processing (P3 potentials) in highly apathetic PD patients, we were particularly interested to see if this relationship exists in a sample of PD patients with heterogeneous levels of apathy. Non-demented patients with PD receiving dopaminergic treatment (n = 14) and healthy control participants (n = 12) completed a three-stimulus oddball task while EEG was recorded. Relative to controls, the PD patients exhibited reductions in centrofrontally distributed P3 potentials when viewing novel distracters during this task. Distracter-related P3 amplitudes evoked by novel distracters were strongly associated with apathy symptoms, even after controlling for the effects of depression, anxiety, and executive function. Executive dysfunction was also predictive of novelty-related P3 processing, yet this relationship was independent from that of apathy. These findings suggest that the brain’s electrophysiological response to novelty is closely related to both motivational and cognitive symptoms in PD, even for patients whose apathy symptoms are not excessive. These results have significant implications for our understanding of non-motor symptoms in this clinical population. PMID:27445962

  13. Neural Correlates of Novelty and Face-Age Effects in Young and Elderly Adults

    PubMed Central

    Wright, Christopher I.; Negreira, Alyson; Gold, Andrea L.; Britton, Jennifer C.; Williams, Danielle; Barrett, Lisa Feldman

    2008-01-01

    The human amygdala preferentially responds to objects of potential value, such as hedonically valenced and novel stimuli. Many studies have documented age-related differences in amygdala responses to valenced stimuli, but relatively little is known about age-related changes in the amygdala’s response to novelty. This study examines whether there are differences in amygdala novelty responses in two different age groups. Healthy young and elderly adults viewed both young and elderly faces that were seen many times (familiar faces) or only once (novel faces) in the context of an fMRI study. We observed that amygdala responses to novel (versus familiar) faces were preserved with aging, suggesting that novelty processing in the amygdala remains stable across the lifespan. In addition, participants demonstrated larger amygdala responses to target faces of the same age group than to age out-group target faces (i.e., an age in-group effect). Differences in anatomic localization and behavioral results suggest that novelty and age in-group effects were differentially processed in the amygdala. PMID:18586522

  14. Stimulus Novelty Energizes Actions in the Absence of Explicit Reward

    PubMed Central

    Koster, Raphael; Seow, Tricia X.; Dolan, Raymond J.; Düzel, Emrah

    2016-01-01

    Novelty seeking has been tied to impulsive choice and biased value based choice. It has been postulated that novel stimuli should trigger more vigorous approach and exploration. However, it is unclear whether stimulus novelty can enhance simple motor actions in the absence of explicit reward, a necessary condition for energizing approach and exploration in an entirely unfamiliar situation. In this study human subjects were cued to omit or perform actions in form of button presses by novel or familiar images. We found that subjects’ motor actions were faster when cued by a novel compared to a familiar image. This facilitation by novelty was strongest when the delay between cue and action was short, consistent with a link between novelty and impulsive choices. The facilitation of reaction times by novelty was correlated across subjects with trait novelty seeking as measured in the Tridimensional Personality Questionnaire. However, this li between high novelty-seeking and action facilitation was driven by trials with a long delay between cue and action. This prolonged time window of energization following novelty could hint at a mechanistic underpinning of enhanced vigour for approach and exploration frequently postulated for novelty seeking humans. In conclusion, we show that stimulus novelty enhances the speed of a cued motor action. We suggest this is likely to reflect an adaptation to changing environments but may also provide a source of maladaptive choice and impulsive behaviour. PMID:27415631

  15. [Contributions and novelties from Functional Analytic Psychotherapy].

    PubMed

    Ferro García, Rafael; Valero Aguayo, Luis; López Bermúdez, Miguel A

    2007-08-01

    Functional Analytic Psychotherapy is based on the principles of radical behaviourism. It emphasises the impact of events occurring during therapeutic sessions, the therapist-client interaction context, functional equivalence of environments, natural reinforcement, and shaping by the therapist. Functional Analytic Psychotherapy makes use of both the basic principles of behaviour analysis: individual functional assessment and application of in vivo treatment. This paper analyses novelties and new contributions of this therapy. New contributions are classified in various categories: integration with other psychotherapies, improvement of therapeutic skills, methods for evaluation and data recording in therapy, its application to several clinical problems, and studies of its efficacy. PMID:17617985

  16. Novelty filter that uses a bacteriorhodopsin film

    NASA Astrophysics Data System (ADS)

    Okamoto, Takayuki; Yamaguchi, Ichirou; Boothroyd, Simon A.; Chrostowski, Jacek

    1997-01-01

    We propose a new novelty optical filter that uses a bacteriorhodopsin film. This filter is based on the time-dependent nonlinear diffraction efficiency of real-time holograms recorded in the film. As soon as the signal beam carrying a pattern is diffracted by the polarization hologram recorded in the bacteriorhodopsin film, it begins to erase the hologram and suppresses the diffraction of the beam at the position of the stationary part of the pattern. This filter enhances only leading edges of moving patterns. In this system undesired scattered light, which is orthogonally polarized to the diffracted beam, is discriminated by a polarizer.

  17. Initiation of segmental locomotor-like activities by stimulation of ventrolateral funiculus in the neonatal rat.

    PubMed

    Cheng, Jianguo; Magnuson, David S K

    2011-09-01

    Descending control is critically important for the generation of locomotor activities. Yet, our understanding of the descending control system of locomotion is limited. We hypothesized that stimulation of the ventrolateral funiculus (VLF) induces rhythmic activity in lumbar neurons that is correlated with locomotor-like activity in the neonatal rat. Intracellular recordings were conducted in the L2-L3 lumbar segments, while locomotor-like output was monitored in the L2 and L5 ventral roots. Stimulation of the VLF at thoracic segments induced locomotor-like activity in the L2 and L5 ventral roots in majority of the preparations (26/33). In a few midline split cord preparations (4/13), VLF stimulation induced rhythmic locomotor-like bursts in either L2 or L5 ventral root without alternating pattern between the ventral roots. The response latencies suggest that VLF stimulation induced antidromic activation (<1 ms, 8 cells), monosynaptic activation (1-3 ms, 18 cells), and oligosynaptic activation (3.5-5 ms, 14 cells) of segmental neurons in the lumbar region. VLF stimulation induced rhythmic membrane potential oscillations with or without bursting of action potentials in 9 of 40 putative interneurons. The membrane potential oscillations were in phase with the locomotor-like output of the L2 ventral root in 7 of the 9 cells while the other 2 cells oscillated in phase with the L5 ventral root activity. We have thus demonstrated that descending axons exist in the VLF which make synaptic connections with segmental neurons in the lumbar region that may be a critical element of the locomotor neural network for the initiation of locomotion. PMID:21858680

  18. Initiation of segmental locomotor-like activities by stimulation of ventrolateral funiculus in the neonatal rat

    PubMed Central

    Magnuson, David S. K.

    2011-01-01

    Descending control is critically important for the generation of locomotor activities. Yet, our understanding of the descending control system of locomotion is limited. We hypothesized that stimulation of the ventrolateral funiculus (VLF) induces rhythmic activity in lumbar neurons that is correlated with locomotor-like activity in the neonatal rat. Intracellular recordings were conducted in the L2–L3 lumbar segments, while locomotor-like output was monitored in the L2 and L5 ventral roots. Stimulation of the VLF at thoracic segments induced locomotor-like activity in the L2 and L5 ventral roots in majority of the preparations (26/33). In a few midline split cord preparations (4/13), VLF stimulation induced rhythmic locomotor-like bursts in either L2 or L5 ventral root without alternating pattern between the ventral roots. The response latencies suggest that VLF stimulation induced antidromic activation (<1 ms, 8 cells), monosynaptic activation (1–3 ms, 18 cells), and oligosynaptic activation (3.5–5 ms, 14 cells) of segmental neurons in the lumbar region. VLF stimulation induced rhythmic membrane potential oscillations with or without bursting of action potentials in 9 of 40 putative interneurons. The membrane potential oscillations were in phase with the locomotor-like output of the L2 ventral root in 7 of the 9 cells while the other 2 cells oscillated in phase with the L5 ventral root activity. We have thus demonstrated that descending axons exist in the VLF which make synaptic connections with segmental neurons in the lumbar region that may be a critical element of the locomotor neural network for the initiation of locomotion. PMID:21858680

  19. Neuronal control of locomotor handedness in Drosophila

    PubMed Central

    Buchanan, Sean M.; Kain, Jamey S.; de Bivort, Benjamin L.

    2015-01-01

    Genetically identical individuals display variability in their physiology, morphology, and behaviors, even when reared in essentially identical environments, but there is little mechanistic understanding of the basis of such variation. Here, we investigated whether Drosophila melanogaster displays individual-to-individual variation in locomotor behaviors. We developed a new high-throughout platform capable of measuring the exploratory behavior of hundreds of individual flies simultaneously. With this approach, we find that, during exploratory walking, individual flies exhibit significant bias in their left vs. right locomotor choices, with some flies being strongly left biased or right biased. This idiosyncrasy was present in all genotypes examined, including wild-derived populations and inbred isogenic laboratory strains. The biases of individual flies persist for their lifetime and are nonheritable: i.e., mating two left-biased individuals does not yield left-biased progeny. This locomotor handedness is uncorrelated with other asymmetries, such as the handedness of gut twisting, leg-length asymmetry, and wing-folding preference. Using transgenics and mutants, we find that the magnitude of locomotor handedness is under the control of columnar neurons within the central complex, a brain region implicated in motor planning and execution. When these neurons are silenced, exploratory laterality increases, with more extreme leftiness and rightiness. This observation intriguingly implies that the brain may be able to dynamically regulate behavioral individuality. PMID:25953337

  20. Locomotor Experience Affects Self and Emotion

    ERIC Educational Resources Information Center

    Uchiyama, Ichiro; Anderson, David I.; Campos, Joseph J.; Witherington, David; Frankel, Carl B.; Lejeune, Laure; Barbu-Roth, Marianne

    2008-01-01

    Two studies investigated the role of locomotor experience on visual proprioception in 8-month-old infants. "Visual proprioception" refers to the sense of self-motion induced in a static person by patterns of optic flow. A moving room apparatus permitted displacement of an entire enclosure (except for the floor) or the side walls and ceiling. In…

  1. Neuronal control of locomotor handedness in Drosophila.

    PubMed

    Buchanan, Sean M; Kain, Jamey S; de Bivort, Benjamin L

    2015-05-26

    Genetically identical individuals display variability in their physiology, morphology, and behaviors, even when reared in essentially identical environments, but there is little mechanistic understanding of the basis of such variation. Here, we investigated whether Drosophila melanogaster displays individual-to-individual variation in locomotor behaviors. We developed a new high-throughout platform capable of measuring the exploratory behavior of hundreds of individual flies simultaneously. With this approach, we find that, during exploratory walking, individual flies exhibit significant bias in their left vs. right locomotor choices, with some flies being strongly left biased or right biased. This idiosyncrasy was present in all genotypes examined, including wild-derived populations and inbred isogenic laboratory strains. The biases of individual flies persist for their lifetime and are nonheritable: i.e., mating two left-biased individuals does not yield left-biased progeny. This locomotor handedness is uncorrelated with other asymmetries, such as the handedness of gut twisting, leg-length asymmetry, and wing-folding preference. Using transgenics and mutants, we find that the magnitude of locomotor handedness is under the control of columnar neurons within the central complex, a brain region implicated in motor planning and execution. When these neurons are silenced, exploratory laterality increases, with more extreme leftiness and rightiness. This observation intriguingly implies that the brain may be able to dynamically regulate behavioral individuality. PMID:25953337

  2. Cocaine counteracts LPS-induced hypolocomotion and triggers locomotor sensitization expression.

    PubMed

    Tortorelli, Lucas Silva; Engelke, Douglas Senna; Lunardi, Paula; Mello E Souza, Tadeu; Santos-Junior, Jair Guilherme; Gonçalves, Carlos-Alberto

    2015-01-01

    Neuroimmune signalling underlies addiction and comorbid depression. Clinical observations indicate that infections and chronic lesions are more frequent in drug users and elevated inflammatory states are evident in cocaine dependents. Therefore, lipopolysaccharide (LPS) and inflammatory cytokines represent an important tool for the investigation of sickness, depressive illness and addiction behaviour. A major component of addiction is the progressive and persistent increase in locomotor activity after repeated drug administration and even prolonged periods of abstinence. The aim of this study was to investigate the response of locomotor sensitization when a non-sensitizing dose of cocaine is paired with a systemic inflammatory stimulus. LPS and cocaine were administered intraperitonealy in young-adult male C57bl/6 mice during a 5-day acquisition phase. After a 48-h withdrawal period all groups were challenged with cocaine to evaluate locomotor expression. During the acquisition phase, the LPS-treated groups displayed characteristic hypolocomotion related to sickness behaviour. The low dose of cocaine did not increase the distance travelled, characterizing a non-sensitization dose. Groups that received both LPS and cocaine did not display hypolocomotion, indicating that cocaine might counteract hypolocomotion sickness behaviour. Moreover, during challenge, only these animals expressed locomotor sensitization. Our results indicate that LPS could facilitate the expression of locomotor sensitization in mice and that the immune system may modulate cocaine-induced sensitization. PMID:25835320

  3. The Novelty Exploration Bonus and Its Attentional Modulation

    ERIC Educational Resources Information Center

    Krebs, Ruth M.; Schott, Bjorn H.; Schutze, Hartmut; Duzel, Emrah

    2009-01-01

    We hypothesized that novel stimuli represent salient learning signals that can motivate "exploration" in search for potential rewards. In computational theories of reinforcement learning, this is referred to as the novelty "exploration bonus" for rewards. If true, stimulus novelty should enhance the reward anticipation signals in brain areas that…

  4. Redundancy and Novelty Mining in the Business Blogosphere

    ERIC Educational Resources Information Center

    Tsai, Flora S.; Chan, Kap Luk

    2010-01-01

    Purpose: The paper aims to explore the performance of redundancy and novelty mining in the business blogosphere, which has not been studied before. Design/methodology/approach: Novelty mining techniques are implemented to single out novel information out of a massive set of text documents. This paper adopted the mixed metric approach which…

  5. Monitoring Locomotor Load in Soccer: Is Metabolic Power, Powerful?

    PubMed

    Buchheit, M; Manouvrier, C; Cassirame, J; Morin, J-B

    2015-12-01

    The aim of the present study was to examine the validity and reliability of metabolic power (P) estimated from locomotor demands during soccer-specific drills. 14 highly-trained soccer players performed a soccer-specific circuit with the ball (3×1-min bouts, interspersed with 30-s passive recovery) on 2 different occasions. Locomotor activity was monitored with 4-Hz GPSs, while oxygen update (VO2) was collected with a portable gas analyzer. P was calculated using either net VO2 responses and traditional calorimetry principles (PVO2, W.kg(-1)) or locomotor demands (PGPS, W.kg(-1)). Distance covered into different speed, acceleration and P zones was recorded. While PGPS was 29±10% lower than PVO2 (d<- 3) during the exercise bouts, it was 85±7% lower (d<- 8) during recovery phases. The typical error between PGPS vs. PVO2 was moderate: 19.8%, 90% confidence limits: (18.4;21.6). The correlation between both estimates of P was small: 0.24 (0.14;0.33). Very large day-to-day variations were observed for acceleration, deceleration and > 20 W.kg(-1) distances (all CVs > 50%), while average Po2 and PGPS showed CVs < 10%. ICC ranged from very low- (acceleration and > 20 W.kg(-1) distances) to-very high (PVO2). PGPS largely underestimates the energy demands of soccer-specific drills, especially during the recovery phases. The poor reliability of PGPS >20 W.kg(-1) questions its value for monitoring purposes in soccer. PMID:26393813

  6. Development of a Countermeasure to Mitigate Postflight Locomotor Dysfunction

    NASA Technical Reports Server (NTRS)

    Bloomberg, J. J.; Mulavara, A. P.; Peters, B. T.; Cohen, H. S.; Richards, J. T.; Miller, C. A.; Brady, R.; Warren, L. E.; Ruttley, T. M.

    2006-01-01

    Astronauts returning from space flight experience locomotor dysfunction following their return to Earth. Our laboratory is currently developing a gait adaptability training program that is designed to facilitate recovery of locomotor function following a return to a gravitational environment. The training program exploits the ability of the sensorimotor system to generalize from exposure to multiple adaptive challenges during training so that the gait control system essentially learns to learn and therefore can reorganize more rapidly when faced with a novel adaptive challenge. Evidence for the potential efficacy of an adaptive generalization gait training program can be obtained from numerous studies in the motor learning literature which have demonstrated that systematically varying the conditions of training enhances the ability of the performer to learn and retain a novel motor task. These variable practice training approaches have been used in applied contexts to improve motor skills required in a number of different sports. The central nervous system (CNS) can produce voluntary movement in an almost infinite number of ways. For example, locomotion can be achieved with many different combinations of joint angles, muscle activation patterns and forces. The CNS can exploit these degrees of freedom to enhance motor response adaptability during periods of adaptive flux like that encountered during a change in gravitational environment. Ultimately, the functional goal of an adaptive generalization countermeasure is not necessarily to immediately return movement patterns back to normal. Rather the training regimen should facilitate the reorganization of available sensory and motor subsystems to achieve safe and effective locomotion as soon as possible after long duration space flight. Indeed, this approach has been proposed as a basic feature underlying effective neurological rehabilitation. We have previously confirmed that subjects participating in an adaptive

  7. Neuronal adaptation, novelty detection and regularity encoding in audition

    PubMed Central

    Malmierca, Manuel S.; Sanchez-Vives, Maria V.; Escera, Carles; Bendixen, Alexandra

    2014-01-01

    The ability to detect unexpected stimuli in the acoustic environment and determine their behavioral relevance to plan an appropriate reaction is critical for survival. This perspective article brings together several viewpoints and discusses current advances in understanding the mechanisms the auditory system implements to extract relevant information from incoming inputs and to identify unexpected events. This extraordinary sensitivity relies on the capacity to codify acoustic regularities, and is based on encoding properties that are present as early as the auditory midbrain. We review state-of-the-art studies on the processing of stimulus changes using non-invasive methods to record the summed electrical potentials in humans, and those that examine single-neuron responses in animal models. Human data will be based on mismatch negativity (MMN) and enhanced middle latency responses (MLR). Animal data will be based on the activity of single neurons at the cortical and subcortical levels, relating selective responses to novel stimuli to the MMN and to stimulus-specific neural adaptation (SSA). Theoretical models of the neural mechanisms that could create SSA and novelty responses will also be discussed. PMID:25009474

  8. Are novel objects perceived as stressful? The effect of novelty on heart rate.

    PubMed

    Fischer, Clare Parker; Franco, Leor A; Romero, L Michael

    2016-07-01

    Neophobia, or the fear of novel objects, is a behavior that is often found in wild animals. Neophobia appears to be related to the physiological stress response because individuals with higher glucocorticoid responses to stress often are more neophobic. The relationship between the heart rate response and novelty, however, has not been tested in a wild species. We implanted heart rate transmitters in captive European starlings (Sturnus vulgaris) to measure increases in heart rate as an index of the adrenomedullary stress response. Specifically, we measured heart rate in animals encountering novel objects on or near their food dishes using a system to display the novel objects while the experimenters remained outside the room, thereby minimizing the confounding effects of experimenter presence on heart rate. We analyzed three conditions: the period of adjustment to the experimental setup before any exposure to novelty, novel object trials, and no object controls (presented in a random order after 0-5 novel objects). Birds approached their food dishes faster during the adjustment period than during novel object trials. Although they demonstrated a behavioral aversion to novelty, the effect on heart rate was unexpected. Heart rate increased sharply when the food dishes were displayed. The duration of the startle response was longer during no object controls than during novel object exposure, the opposite of the anticipated result. There were no correlations between behavior and metrics of the heart rate response. Novel object exposure does not cause an increase in heart rate. PMID:27072510

  9. Vector Symbolic Spiking Neural Network Model of Hippocampal Subarea CA1 Novelty Detection Functionality.

    PubMed

    Agerskov, Claus

    2016-04-01

    A neural network model is presented of novelty detection in the CA1 subdomain of the hippocampal formation from the perspective of information flow. This computational model is restricted on several levels by both anatomical information about hippocampal circuitry and behavioral data from studies done in rats. Several studies report that the CA1 area broadcasts a generalized novelty signal in response to changes in the environment. Using the neural engineering framework developed by Eliasmith et al., a spiking neural network architecture is created that is able to compare high-dimensional vectors, symbolizing semantic information, according to the semantic pointer hypothesis. This model then computes the similarity between the vectors, as both direct inputs and a recalled memory from a long-term memory network by performing the dot-product operation in a novelty neural network architecture. The developed CA1 model agrees with available neuroanatomical data, as well as the presented behavioral data, and so it is a biologically realistic model of novelty detection in the hippocampus, which can provide a feasible explanation for experimentally observed dynamics. PMID:26890351

  10. Neurochemical modulation of repetition suppression and novelty signals in the human brain.

    PubMed

    Bunzeck, Nico; Thiel, Christiane

    2016-07-01

    The repeated processing of a sensory stimulus, such as a picture or sound, leads to a decrement in response in neurons that fired to the initial presentation. These effects are well known from single cell recordings in the inferior temporal cortex in monkeys, and functional neuroimaging in humans on large-scale neural activity could show similar effects in extrastriate, frontal and medial temporal lobe (MTL) regions. The role of specific neurotransmitters in repeated processing of information is, however, less clear. In the first part of this article, we will introduce the two concepts of repetition suppression and novelty signals, which is followed by a brief overview of pharmacological neuroimaging in humans. We will then summarize human studies suggesting that gamma-aminobutyric-acid (GABA) and acetylcholine (ACh) play an important role in modulating behavioral priming and associated repetition suppression in extrastriate and frontal brain regions. Finally, we review studies on neural novelty signals in the dopaminergic mesolimbic system, and conclude that dopamine (DA) regulates the temporal aspects of novelty processing and closely relates to long-term memory encoding rather than behavioral priming. As such, this review describes differential roles of GABA, ACh and DA in repeated stimulus processing, and further suggests that repetition suppression and neural novelty signals may not be two sides of the same coin but rather independent processes. PMID:26625882

  11. Effect of Environmental Conditions and Toxic Compounds on the Locomotor Activity of Pediculus humanus capitis (Phthiraptera: Pediculidae).

    PubMed

    Ortega-Insaurralde, I; Toloza, A C; Gonzalez-Audino, P; Mougabure-Cueto, G A; Alvarez-Costa, A; Roca-Acevedo, G; Picollo, M I

    2015-09-01

    In this work, we evaluated the effect of environmental variables such as temperature, humidity, and light on the locomotor activity of Pediculus humanus capitis. In addition, we used selected conditions of temperature, humidity, and light to study the effects of cypermethrin and N,N-diethyl-3-methylbenzamide (DEET) on the locomotor activity of head lice. Head lice increased their locomotor activity in an arena at 30°C compared with activity at 20°C. When we tested the influence of the humidity level, the locomotor activity of head lice showed no significant differences related to humidity level, both at 30°C and 20°C. Concerning light influence, we observed that the higher the intensity of light, the slower the movement of head lice. We also demonstrated that sublethal doses of toxics may alter locomotor activity in adults of head lice. Sublethal doses of cypermethrin induced hyperactivated responses in adult head lice. Sublethal doses of DEET evocated hypoactivated responses in head lice. The observation of stereotyped behavior in head lice elicited by toxic compounds proved that measuring locomotor activity in an experimental set-up where environmental conditions are controlled would be appropriate to evaluate compounds of biological importance, such as molecules involved in the host-parasite interaction and intraspecific relationships. PMID:26336260

  12. The evolution of locomotor rhythmicity in tetrapods.

    PubMed

    Ross, Callum F; Blob, Richard W; Carrier, David R; Daley, Monica A; Deban, Stephen M; Demes, Brigitte; Gripper, Janaya L; Iriarte-Diaz, Jose; Kilbourne, Brandon M; Landberg, Tobias; Polk, John D; Schilling, Nadja; Vanhooydonck, Bieke

    2013-04-01

    Differences in rhythmicity (relative variance in cycle period) among mammal, fish, and lizard feeding systems have been hypothesized to be associated with differences in their sensorimotor control systems. We tested this hypothesis by examining whether the locomotion of tachymetabolic tetrapods (birds and mammals) is more rhythmic than that of bradymetabolic tetrapods (lizards, alligators, turtles, salamanders). Species averages of intraindividual coefficients of variation in cycle period were compared while controlling for gait and substrate. Variance in locomotor cycle periods is significantly lower in tachymetabolic than in bradymetabolic animals for datasets that include treadmill locomotion, non-treadmill locomotion, or both. When phylogenetic relationships are taken into account the pooled analyses remain significant, whereas the non-treadmill and the treadmill analyses become nonsignificant. The co-occurrence of relatively high rhythmicity in both feeding and locomotor systems of tachymetabolic tetrapods suggests that the anatomical substrate of rhythmicity is in the motor control system, not in the musculoskeletal components. PMID:23550769

  13. The immediate early gene Egr3 mediates adaptation to stress and novelty

    PubMed Central

    Gallitano-Mendel1, Amelia; Izumi, Yukitoshi; Tokuda, Kazuhiro; Zorumski, Charles F.; Howell, Maureen P.; Muglia, Louis J.; Wozniak, David F.; Milbrandt, Jeffrey

    2007-01-01

    Stress and exploration of novel environments induce neural expression of immediate early gene transcription factors (IEG-TFs). However, as yet no IEG-TF has been shown to be required for the normal biological or behavioral responses to these stimuli. Here we show that mice deficient for the IEG-TF early growth response gene (Egr) 3, display accentuated behavioral responses to the mild stress of handling paralleled by increased release of the stress hormone corticosterone. Egr3−/− mice also display abnormal responses to novelty, including heightened reactivity to novel environments and failure to habituate to social cues or startling acoustic stimuli. In a Y-maze spontaneous alternation task, they perform fewer sequential arm entries than controls, suggesting defects in immediate memory. Because stress and novelty stimulate hippocampal long-term depression (LTD), and because abnormalities in habituation to novelty and Y-maze performance have been associated with LTD deficits, we examined this form of synaptic plasticity in Egr3−/− mice. We found that Egr3−/− mice fail to establish hippocampal LTD in response to low frequency stimulation and exhibit dysfunction of an ifenprodil-sensitive (NR1/NR2B) NMDA receptor subclass. LTP induction was not altered. The NR2B-dependent dysfunction does not result from transcriptional regulation of this subunit by Egr3, because NR2B mRNA levels did not differ in the hippocampi of Egr3−/− and control mice. These findings are the first demonstration of the requirement for an IEG-TF in mediating the response to stress and novelty, and in the establishment of LTD. PMID:17692471

  14. Effects of cocaine on locomotor activity and schedule-controlled behaviors of inbred rat strains.

    PubMed

    Witkin, J M; Goldberg, S R

    1990-10-01

    Effects of cocaine on several behaviors considered to be reflective of psychomotor stimulation were compared in F344/CR1BR and NBR/NIH inbred rat strains. Effects of cocaine on locomotor activity were compared with effects on either bar-press or nose-poke responses maintained under a multiple fixed-interval 3-min, timeout 1-min schedule of food presentation. In locomotor activity experiments, NBR rats were twice as active as F344 rats under baseline conditions and displayed dose-dependent increases in locomotion (5-20 mg/kg). Maximal increases in locomotor activity of F344 rats were only 200% compared to 1000% in NBR rats. In contrast to locomotor activity, no strain differences in the effects of cocaine were observed under the schedules of food delivery. Bar-pressing under the fixed-interval schedule was increased to a maximum of 150% of control in both rat strains. Nose-poke responding under the fixed-interval schedule was not significantly increased, but timeout rates were increased in both strains. These results suggest that NBR and F344 rats do not differ in general sensitivity to stimulant effects of cocaine but exhibit marked differences in responsivity to cocaine that are dependent upon the behavior studied. Further delineation of the behavioral specificity of strain differences in sensitivity to cocaine should help to identify neurobiological substrates underlying unique biologically determined responses to cocaine. PMID:2080195

  15. The availability of novelty sweets within high school localities.

    PubMed

    Aljawad, A; Morgan, M Z; Rees, J S; Fairchild, R

    2016-06-10

    Background Reducing sugar consumption is a primary focus of current global public health policy. Achieving 5% of total energy from free sugars will be difficult acknowledging the concentration of free sugars in sugar sweetened beverages, confectionery and as hidden sugars in many savoury items. The expansion of the novelty sweet market in the UK has significant implications for children and young adults as they contribute to dental caries, dental erosion and obesity.Objective To identify the most available types of novelty sweets within the high school fringe in Cardiff, UK and to assess their price range and where and how they were displayed in shops.Subjects and methods Shops within a ten minute walking distance around five purposively selected high schools in the Cardiff aea representing different levels of deprivation were visited. Shops in Cardiff city centre and three supermarkets were also visited to identify the most commonly available novelty sweets.Results The ten most popular novelty sweets identified in these scoping visits were (in descending order): Brain Licker, Push Pop, Juicy Drop, Lickedy Lips, Big Baby Pop, Vimto candy spray, Toxic Waste, Tango candy spray, Brain Blasterz Bitz and Mega Mouth candy spray. Novelty sweets were located on low shelves which were accessible to all age-groups in 73% (14 out of 19) of the shops. Novelty sweets were displayed in the checkout area in 37% (seven out of 19) shops. The price of the top ten novelty sweets ranged from 39p to £1.Conclusion A wide range of acidic and sugary novelty sweets were easily accessible and priced within pocket money range. Those personnel involved in delivering dental and wider health education or health promotion need to be aware of recent developments in children's confectionery. The potential effects of these novelty sweets on both general and dental health require further investigation. PMID:27283564

  16. Acts of kindness and acts of novelty affect life satisfaction.

    PubMed

    Buchanan, Kathryn E; Bardi, Anat

    2010-01-01

    The present experiment was designed to establish the effects of acts of kindness and acts of novelty on life satisfaction. Participants aged 18-60 took part on a voluntary basis. They were randomly assigned to perform either acts of kindness, acts of novelty, or no acts on a daily basis for 10 days. Their life satisfaction was measured before and after the 10-day experiment. As expected, performing acts of kindness or acts of novelty resulted in an increase in life satisfaction. PMID:20575332

  17. Mephedrone interactions with cocaine: prior exposure to ‘bath salt’ constituent enhances cocaine-induced locomotor activation in rats

    PubMed Central

    Gregg, Ryan A.; Tallarida, Christopher S.; Reitz, Allen B.; Rawls, Scott M.

    2014-01-01

    Concurrent use of mephedrone (4-methylmethcathinone) (MEPH) and established drugs of abuse is now commonplace, but knowledge about interactions between these drugs is sparse. The present study was designed to test the hypothesis that prior MEPH exposure enhances the locomotor-stimulant effects of cocaine and methamphetamine (METH). For cocaine experiments, rats pretreated with saline, cocaine (15 mg/kg), or MEPH (15 mg/kg) for 5 days were injected with cocaine after 10 days of drug absence. For METH experiments, rats pretreated with saline, METH (2 mg/kg), or MEPH (15 mg/kg) were injected with METH after 10 days of drug absence. Cocaine challenge produced greater locomotor activity following pretreatment with cocaine or MEPH than following pretreatment with saline. METH challenge produced greater locomotor activity following METH pretreatment than following saline pretreatment; however, locomotor activity in rats pretreated with MEPH or saline and then challenged with METH was not significantly different. The locomotor response to MEPH (15 mg/kg) was not significantly affected by pretreatment with cocaine (15 mg/kg) or METH (0.5, 2 mg/kg). The present demonstration that cocaine-induced locomotor activation is enhanced by prior MEPH exposure suggests that MEPH cross-sensitizes to cocaine and increases cocaine efficacy. Interestingly, MEPH cross-sensitization was not bi-directional and did not extend to METH, suggesting the phenomenon is sensitive to specific psychostimulants. PMID:24126218

  18. Mephedrone interactions with cocaine: prior exposure to the 'bath salt' constituent enhances cocaine-induced locomotor activation in rats.

    PubMed

    Gregg, Ryan A; Tallarida, Christopher S; Reitz, Allen B; Rawls, Scott M

    2013-12-01

    Concurrent use of mephedrone (4-methylmethcathinone; MEPH) and established drugs of abuse is now commonplace, but knowledge about interactions between these drugs is sparse. The present study was designed to test the hypothesis that prior MEPH exposure enhances the locomotor-stimulant effects of cocaine and methamphetamine (METH). For cocaine experiments, rats pretreated with saline, cocaine (15 mg/kg), or MEPH (15 mg/kg) for 5 days were injected with cocaine after 10 days of drug absence. For METH experiments, rats pretreated with saline, METH (2 mg/kg), or MEPH (15 mg/kg) were injected with METH after 10 days of drug absence. Cocaine challenge produced greater locomotor activity after pretreatment with cocaine or MEPH than after pretreatment with saline. METH challenge produced greater locomotor activity after METH pretreatment than after saline pretreatment; however, locomotor activity in rats pretreated with MEPH or saline and then challenged with METH was not significantly different. The locomotor response to MEPH (15 mg/kg) was not significantly affected by pretreatment with cocaine (15 mg/kg) or METH (0.5, 2 mg/kg). The present demonstration that cocaine-induced locomotor activation is enhanced by prior MEPH exposure suggests that MEPH cross-sensitizes to cocaine and increases cocaine efficacy. Interestingly, MEPH cross-sensitization was not bidirectional and did not extend to METH, suggesting that the phenomenon is sensitive to specific psychostimulants. PMID:24126218

  19. Novelty, Stress, and Biological Roots in Human Market Behavior

    PubMed Central

    Sarapultsev, Alexey; Sarapultsev, Petr

    2014-01-01

    Although studies examining the biological roots of human behavior have been conducted since the seminal work Kahneman and Tversky, crises and panics have not disappeared. The frequent occurrence of various types of crises has led some economists to the conviction that financial markets occasionally praise irrational judgments and that market crashes cannot be avoided a priori (Sornette 2009; Smith 2004). From a biological point of view, human behaviors are essentially the same during crises accompanied by stock market crashes and during bubble growth when share prices exceed historic highs. During those periods, most market participants see something new for themselves, and this inevitably induces a stress response in them with accompanying changes in their endocrine profiles and motivations. The result is quantitative and qualitative changes in behavior (Zhukov 2007). An underestimation of the role of novelty as a stressor is the primary shortcoming of current approaches for market research. When developing a mathematical market model, it is necessary to account for the biologically determined diphasisms of human behavior in everyday low-stress conditions and in response to stressors. This is the only type of approach that will enable forecasts of market dynamics and investor behaviors under normal conditions as well as during bubbles and panics. PMID:25379268

  20. A parallel cholinergic brainstem pathway for enhancing locomotor drive

    PubMed Central

    Smetana, Roy; Juvin, Laurent; Dubuc, Réjean; Alford, Simon

    2010-01-01

    The brainstem locomotor system is believed to be organized serially from the mesencephalic locomotor region (MLR) to reticulospinal neurons, which in turn, project to locomotor neurons in the spinal cord. In contrast, we now identify in lampreys, brainstem muscarinoceptive neurons receiving parallel inputs from the MLR and projecting back to reticulospinal cells to amplify and extend durations of locomotor output. These cells respond to muscarine with extended periods of excitation, receive direct muscarinic excitation from the MLR, and project glutamatergic excitation to reticulospinal neurons. Targeted block of muscarine receptors over these neurons profoundly reduces MLR-induced excitation of reticulospinal neurons and markedly slows MLR-evoked locomotion. Their presence forces us to rethink the organization of supraspinal locomotor control, to include a sustained feedforward loop that boosts locomotor output. PMID:20473293

  1. Novelty is not enough: laser-evoked potentials are determined by stimulus saliency, not absolute novelty

    PubMed Central

    Ronga, I.; Valentini, E.; Mouraux, A.

    2013-01-01

    Event-related potentials (ERPs) elicited by transient nociceptive stimuli in humans are largely sensitive to bottom-up novelty induced, for example, by changes in stimulus attributes (e.g., modality or spatial location) within a stream of repeated stimuli. Here we aimed 1) to test the contribution of a selective change of the intensity of a repeated stimulus in determining the magnitude of nociceptive ERPs, and 2) to dissect the effect of this change of intensity in terms of “novelty” and “saliency” (an increase of stimulus intensity is more salient than a decrease of stimulus intensity). Nociceptive ERPs were elicited by trains of three consecutive laser stimuli (S1-S2-S3) delivered to the hand dorsum at a constant 1-s interstimulus interval. Three, equally spaced intensities were used: low (L), medium (M), and high (H). While the intensities of S1 and S2 were always identical (L, M, or H), the intensity of S3 was either identical (e.g., HHH) or different (e.g., MMH) from the intensity of S1 and S2. Introducing a selective change in stimulus intensity elicited significantly larger N1 and N2 waves of the S3-ERP but only when the change consisted in an increase in stimulus intensity. This observation indicates that nociceptive ERPs do not simply reflect processes involved in the detection of novelty but, instead, are mainly determined by stimulus saliency. PMID:23136349

  2. Effects of coal mine wastewater on locomotor and non-locomotor activities of empire gudgeons (Hypseleotris compressa).

    PubMed

    Lanctôt, C; Melvin, S D; Fabbro, L; Leusch, F D L; Wilson, S P

    2016-05-01

    Coal mining represents an important industry in many countries, but concerns exist about the possible adverse effects of minewater releases on aquatic animals and ecosystems. Coal mining generates large volumes of complex wastewater, which often contains high concentrations of dissolved solids, suspended solids, metals, hydrocarbons, salts and other compounds. Traditional toxicological testing has generally involved the assessment of acute toxicity or chronic toxicity with longer-term tests, and while such tests provide useful information, they are poorly suited to ongoing monitoring or rapid assessment following accidental discharge events. As such, there is considerable interest in developing rapid and sensitive approaches to environmental monitoring, and particularly involving the assessment of sub-lethal behavioural responses in locally relevant aquatic species. We therefore investigated behavioural responses of a native Australian fish to coal mine wastewater, to evaluate its potential use for evaluating sub-lethal effects associated with wastewater releases on freshwater ecosystems. Empire gudgeons (Hypseleotris compressa) were exposed to wastewater from two dams located at an open cut coal mine in Central Queensland, Australia and activity levels were monitored using the Multispecies Freshwater Biomonitor® (LimCo International GmbH). A general decrease in locomotor activity (i.e., low frequency movement) and increase in non-locomotor activity (i.e., high frequency movement including ventilation and small fin movement) was observed in exposed fish compared to those in control water. Altered activity levels were observable within the first hour of exposure and persisted throughout the 15-d experiment. Results demonstrate the potential for using behavioural endpoints as tools for monitoring wastewater discharges using native fish species, but more research is necessary to identify responsible compounds and response thresholds, and to understand the relevance

  3. Development of Testing Methodologies to Evaluate Postflight Locomotor Performance

    NASA Technical Reports Server (NTRS)

    Mulavara, A. P.; Peters, B. T.; Cohen, H. S.; Richards, J. T.; Miller, C. A.; Brady, R.; Warren, L. E.; Bloomberg, J. J.

    2006-01-01

    Crewmembers experience locomotor and postural instabilities during ambulation on Earth following their return from space flight. Gait training programs designed to facilitate recovery of locomotor function following a transition to a gravitational environment need to be accompanied by relevant assessment methodologies to evaluate their efficacy. The goal of this paper is to demonstrate the operational validity of two tests of locomotor function that were used to evaluate performance after long duration space flight missions on the International Space Station (ISS).

  4. Novelty, conditioning and attentional bias to sexual rewards

    PubMed Central

    Banca, Paula; Morris, Laurel S.; Mitchell, Simon; Harrison, Neil A.; Potenza, Marc N.; Voon, Valerie

    2016-01-01

    The Internet provides a large source of novel and rewarding stimuli, particularly with respect to sexually explicit materials. Novelty-seeking and cue-conditioning are fundamental processes underlying preference and approach behaviors implicated in disorders of addiction. Here we examine these processes in individuals with compulsive sexual behaviors (CSB), hypothesizing a greater preference for sexual novelty and stimuli conditioned to sexual rewards relative to healthy volunteers. Twenty-two CSB males and forty age-matched male volunteers were tested in two separate behavioral tasks focusing on preferences for novelty and conditioned stimuli. Twenty subjects from each group were also assessed in a third conditioning and extinction task using functional magnetic resonance imaging. CSB was associated with enhanced novelty preference for sexual, as compared to control images, and a generalized preference for cues conditioned to sexual and monetary versus neutral outcomes compared to healthy volunteers. CSB individuals also had greater dorsal cingulate habituation to repeated sexual versus monetary images with the degree of habituation correlating with enhanced preference for sexual novelty. Approach behaviors to sexually conditioned cues dissociable from novelty preference were associated with an early attentional bias to sexual images. This study shows that CSB individuals have a dysfunctional enhanced preference for sexual novelty possibly mediated by greater cingulate habituation along with a generalized enhancement of conditioning to rewards. We further emphasize a dissociable role for cue-conditioning and novelty preference on the early attentional bias for sexual cues. These findings have wider relevance as the Internet provides a broad range of novel and potentially rewarding stimuli. PMID:26606725

  5. Novelty, conditioning and attentional bias to sexual rewards.

    PubMed

    Banca, Paula; Morris, Laurel S; Mitchell, Simon; Harrison, Neil A; Potenza, Marc N; Voon, Valerie

    2016-01-01

    The Internet provides a large source of novel and rewarding stimuli, particularly with respect to sexually explicit materials. Novelty-seeking and cue-conditioning are fundamental processes underlying preference and approach behaviors implicated in disorders of addiction. Here we examine these processes in individuals with compulsive sexual behaviors (CSB), hypothesizing a greater preference for sexual novelty and stimuli conditioned to sexual rewards relative to healthy volunteers. Twenty-two CSB males and forty age-matched male volunteers were tested in two separate behavioral tasks focusing on preferences for novelty and conditioned stimuli. Twenty subjects from each group were also assessed in a third conditioning and extinction task using functional magnetic resonance imaging. CSB was associated with enhanced novelty preference for sexual, as compared to control images, and a generalized preference for cues conditioned to sexual and monetary versus neutral outcomes compared to healthy volunteers. CSB individuals also had greater dorsal cingulate habituation to repeated sexual versus monetary images with the degree of habituation correlating with enhanced preference for sexual novelty. Approach behaviors to sexually conditioned cues dissociable from novelty preference were associated with an early attentional bias to sexual images. This study shows that CSB individuals have a dysfunctional enhanced preference for sexual novelty possibly mediated by greater cingulate habituation along with a generalized enhancement of conditioning to rewards. We further emphasize a dissociable role for cue-conditioning and novelty preference on the early attentional bias for sexual cues. These findings have wider relevance as the Internet provides a broad range of novel and potentially rewarding stimuli. PMID:26606725

  6. Abandoning objectives: evolution through the search for novelty alone.

    PubMed

    Lehman, Joel; Stanley, Kenneth O

    2011-01-01

    In evolutionary computation, the fitness function normally measures progress toward an objective in the search space, effectively acting as an objective function. Through deception, such objective functions may actually prevent the objective from being reached. While methods exist to mitigate deception, they leave the underlying pathology untreated: Objective functions themselves may actively misdirect search toward dead ends. This paper proposes an approach to circumventing deception that also yields a new perspective on open-ended evolution. Instead of either explicitly seeking an objective or modeling natural evolution to capture open-endedness, the idea is to simply search for behavioral novelty. Even in an objective-based problem, such novelty search ignores the objective. Because many points in the search space collapse to a single behavior, the search for novelty is often feasible. Furthermore, because there are only so many simple behaviors, the search for novelty leads to increasing complexity. By decoupling open-ended search from artificial life worlds, the search for novelty is applicable to real world problems. Counterintuitively, in the maze navigation and biped walking tasks in this paper, novelty search significantly outperforms objective-based search, suggesting the strange conclusion that some problems are best solved by methods that ignore the objective. The main lesson is the inherent limitation of the objective-based paradigm and the unexploited opportunity to guide search through other means. PMID:20868264

  7. Bimodal Respiratory-Locomotor Neurons in the Neonatal Rat Spinal Cord.

    PubMed

    Le Gal, Jean-Patrick; Juvin, Laurent; Cardoit, Laura; Morin, Didier

    2016-01-20

    Neural networks that can generate rhythmic motor output in the absence of sensory feedback, commonly called central pattern generators (CPGs), are involved in many vital functions such as locomotion or respiration. In certain circumstances, these neural networks must interact to produce coordinated motor behavior adapted to environmental constraints and to satisfy the basic needs of an organism. In this context, we recently reported the existence of an ascending excitatory influence from lumbar locomotor CPG circuitry to the medullary respiratory networks that is able to depolarize neurons of the parafacial respiratory group during fictive locomotion and to subsequently induce an increased respiratory rhythmicity (Le Gal et al., 2014b). Here, using an isolated in vitro brainstem-spinal cord preparation from neonatal rat in which the respiratory and the locomotor networks remain intact, we show that during fictive locomotion induced either pharmacologically or by sacrocaudal afferent stimulation, the activity of both thoracolumbar expiratory motoneurons and interneurons is rhythmically modulated with the locomotor activity. Completely absent in spinal inspiratory cells, this rhythmic pattern is highly correlated with the hindlimb ipsilateral flexor activities. Furthermore, silencing brainstem neural circuits by pharmacological manipulation revealed that this locomotor-related drive to expiratory motoneurons is solely dependent on propriospinal pathways. Together these data provide the first evidence in the newborn rat spinal cord for the existence of bimodal respiratory-locomotor motoneurons and interneurons onto which both central efferent expiratory and locomotor drives converge, presumably facilitating the coordination between the rhythmogenic networks responsible for two different motor functions. Significance statement: In freely moving animals, distant regions of the brain and spinal cord controlling distinct motor acts must interact to produce the best

  8. Modelling the locomotor energetics of extinct hominids.

    PubMed

    Kramer, P A

    1999-10-01

    Bipedality is the defining characteristic of Hominidae and, as such, an understanding of the adaptive significance and functional implications of bipedality is imperative to any study of human evolution. Hominid bipedality is, presumably, a solution to some problem for the early hominids, one that has much to do with energy expenditure. Until recently, however, little attention could be focused on the quantifiable energetic aspects of bipedality as a unique locomotor form within Primates because of the inability to measure empirically the energy expenditure of non-modern hominids. A recently published method provides a way of circumventing the empirical measurement dilemma by calculating energy expenditure directly from anatomical variables and movement profiles. Although the origins of bipedality remain clouded, two discernible forms of locomotor anatomy are present in the hominid fossil record: the australopithecine and modern configurations. The australopithecine form is best represented by AL 288-1, a partial skeleton of Australopithecus afarensis, and is characterized as having short legs and a wide pelvis. The modern form is represented by modern humans and has long legs and a narrow pelvis. Human walking is optimized to take advantage of the changing levels of potential and kinetic energy that occur as the body and limbs move through the stride cycle. Although this optimization minimizes energy expenditure, some energy is required to maintain motion. I quantify this energy by developing a dynamic model that uses kinematic equations to determine energy expenditure. By representing both configurations with such a model, I can compare their rates of energy expenditure. I find that the australopithecine configuration uses less energy than that of a modern human. Despite arguments presented in the anthropological literature, the shortness of the legs of AL 288-1 provides no evidence that she was burdened with a compromised or transitional locomotor anatomy

  9. Multilevel Cortical Processing of Somatosensory Novelty: A Magnetoencephalography Study

    PubMed Central

    Naeije, Gilles; Vaulet, Thibaut; Wens, Vincent; Marty, Brice; Goldman, Serge; De Tiège, Xavier

    2016-01-01

    Using magnetoencephalography (MEG), this study investigates the spatio-temporal dynamics of the multilevel cortical processing of somatosensory change detection. Neuromagnetic signals of 16 healthy adult subjects (7 females and 9 males, mean age 29 ± 3 years) were recorded using whole-scalp-covering MEG while they underwent an oddball paradigm based on simple standard (right index fingertip tactile stimulation) and deviant (simultaneous right index fingertip and middle phalanx tactile stimulation) stimuli gathered into sequences to create and then deviate from stimulus patterns at multiple (local vs. global) levels of complexity. Five healthy adult subjects (3 females and 2 males, mean age 31, 6 ± 2 years) also underwent a similar oddball paradigm in which standard and deviant stimuli were flipped. Local deviations led to a somatosensory mismatch response peaking at 55–130 ms post-stimulus onset with a cortical generator located at the contralateral secondary somatosensory (cSII) cortex. The mismatch response was independent of the deviant stimuli physical characteristics. Global deviants led to a P300 response with cortical sources located bilaterally at temporo-parietal junction (TPJ) and supplementary motor area (SMA). The posterior parietal cortex (PPC) and the SMA were found to generate a contingent magnetic variation (CMV) attributed to top-down expectations. Amplitude of mismatch responses were modulated by top-down expectations and correlated with both the magnitude of the CMV and the P300 amplitude at the right TPJ. These results provide novel empirical evidence for a unified sensory novelty detection system in the human brain by linking detection of salient sensory stimuli in personal and extra-personal spaces to a common framework of multilevel cortical processing. PMID:27313523

  10. Multilevel Cortical Processing of Somatosensory Novelty: A Magnetoencephalography Study.

    PubMed

    Naeije, Gilles; Vaulet, Thibaut; Wens, Vincent; Marty, Brice; Goldman, Serge; De Tiège, Xavier

    2016-01-01

    Using magnetoencephalography (MEG), this study investigates the spatio-temporal dynamics of the multilevel cortical processing of somatosensory change detection. Neuromagnetic signals of 16 healthy adult subjects (7 females and 9 males, mean age 29 ± 3 years) were recorded using whole-scalp-covering MEG while they underwent an oddball paradigm based on simple standard (right index fingertip tactile stimulation) and deviant (simultaneous right index fingertip and middle phalanx tactile stimulation) stimuli gathered into sequences to create and then deviate from stimulus patterns at multiple (local vs. global) levels of complexity. Five healthy adult subjects (3 females and 2 males, mean age 31, 6 ± 2 years) also underwent a similar oddball paradigm in which standard and deviant stimuli were flipped. Local deviations led to a somatosensory mismatch response peaking at 55-130 ms post-stimulus onset with a cortical generator located at the contralateral secondary somatosensory (cSII) cortex. The mismatch response was independent of the deviant stimuli physical characteristics. Global deviants led to a P300 response with cortical sources located bilaterally at temporo-parietal junction (TPJ) and supplementary motor area (SMA). The posterior parietal cortex (PPC) and the SMA were found to generate a contingent magnetic variation (CMV) attributed to top-down expectations. Amplitude of mismatch responses were modulated by top-down expectations and correlated with both the magnitude of the CMV and the P300 amplitude at the right TPJ. These results provide novel empirical evidence for a unified sensory novelty detection system in the human brain by linking detection of salient sensory stimuli in personal and extra-personal spaces to a common framework of multilevel cortical processing. PMID:27313523

  11. Escalation of food-maintained responding and sensitivity to the locomotor stimulant effects of cocaine in mice

    PubMed Central

    Goeders, James E.; Murnane, Kevin S.; Banks, Matthew L.; Fantegrossi, William E.

    2009-01-01

    Escalation of drug self-administration is a consequence of extended drug access and is thought to be specifically related to addiction, but few studies have investigated whether intake of non-drug reinforcers may also escalate with extended-access. The goal of these studies was to determine the effects of limited and extended-access to food reinforcers on behavioral and pharmacological endpoints in mice. In distinct groups, responding on a lever was maintained by liquid reinforcement, or nose-poke responses were maintained by sucrose pellets or liquid food in sessions lasting 1 hour (limited-access) or 10 hours (extended-access). The reinforcing strength of each food, as well as reinforcer-associated cues, was tested before and after extended-access using a progressive ratio (PR) schedule, and locomotor activity in response to novelty and increasing doses of cocaine was assessed in an open field setting in all animals after access to food reinforcers. Escalation of lever-pressing behavior reinforced by liquid food, but not nose-poke behavior reinforced by liquid food or sucrose pellets, was observed across successive extended-access sessions. A concomitant increase in the reinforcing strength of liquid food and its associated cues was apparent in mice that escalated their responding, but not in mice that did not escalate. Finally, extended reinforcer access leading to behavioral escalation was accompanied by an increased sensitivity to the psychostimulant effects of cocaine compared to limited-access. These findings indicate that behavioral escalation can develop as a consequence of extended-access to a non-drug reinforcer, although both the nature of the reinforcer (liquid versus solid food) and the topography of the operant response (lever versus nose-poke) modulate its development. These data also suggest that some of the behavioral and pharmacological corrolaries of behavioral escalation observed following extended-access to drug self-administration may not be

  12. Lateralized processing of novel metaphors: disentangling figurativeness and novelty.

    PubMed

    Forgács, Bálint; Lukács, Agnes; Pléh, Csaba

    2014-04-01

    One of the intriguing and sometimes controversial findings in figurative language research is a right-hemisphere processing advantage for novel metaphors. The current divided visual field study introduced novel literal expressions as a control condition to assess processing novelty independent of figurativeness. Participants evaluated word pairs belonging to one of the five categories: (1) conventional metaphorical, (2) conventional literal, (3) novel metaphorical, (4) novel literal, and (5) unrelated expressions in a semantic decision task. We presented expressions without sentence context and controlled for additional factors including emotional valence, arousal, and imageability that could potentially influence hemispheric processing. We also utilized an eye-tracker to ensure lateralized presentation. We did not find the previously reported right-hemispherical processing advantage for novel metaphors. Processing was faster in the left hemisphere for all types of word pairs, and accuracy was also higher in the right visual field - left hemisphere. Novel metaphors were processed just as fast as novel literal expressions, suggesting that the primary challenge during the comprehension of novel expressions is not a serial processing of salience, but perhaps a more left hemisphere weighted semantic integration. Our results cast doubt on the right-hemisphere theory of metaphors, and raise the possibility that other uncontrolled variables were responsible for previous results. The lateralization of processing of two word expressions seems to be more contingent on the specific task at hand than their figurativeness or saliency. PMID:24418155

  13. An automated tracking system for Caenorhabditis elegans locomotor behavior and circadian studies application.

    PubMed

    Simonetta, Sergio H; Golombek, Diego A

    2007-04-15

    Automation of simple behavioral patterns, such as locomotor activity, is fundamental for pharmacological and genetic screening studies. Recently, circadian behaviors in locomotor activity and stress responses were reported in the nematode Caenorhabditis elegans, a well-known model in genetics and developmental studies. Here we present a new method for long-term recordings of C. elegans (as well as other similar-sized animals) locomotor activity based on an infrared microbeam scattering. Individual nematodes were cultured in a 96-well microtiter plate; we tested L15, CeMM and E. coli liquid cultures in long-term activity tracking experiments, and found CeMM to be the optimal medium. Treatment with 0.2% azide caused an immediate decrease in locomotor activity as recorded with our system. In addition to the validation of the method (including hardware and software details), we report its application in chronobiological studies. Circadian rhythms in animals entrained to light-dark and constant dark conditions (n=48 and 96 worms, respectively) at 16 degrees C, were analyzed by LS periodograms. We obtained a 24.2+/-0.44 h period (52% of significantly rhythmic animals) in LD, and a 23.1+/-0.40 h period (37.5% of significantly rhythmic animals) under DD. The system is automateable using microcontrollers, of low-cost construction and highly reproducible. PMID:17207862

  14. Initial locomotor sensitivity to cocaine varies widely among inbred mouse strains.

    PubMed

    Wiltshire, T; Ervin, R B; Duan, H; Bogue, M A; Zamboni, W C; Cook, S; Chung, W; Zou, F; Tarantino, L M

    2015-03-01

    Initial sensitivity to psychostimulants can predict subsequent use and abuse in humans. Acute locomotor activation in response to psychostimulants is commonly used as an animal model of initial drug sensitivity and has been shown to have a substantial genetic component. Identifying the specific genetic differences that lead to phenotypic differences in initial drug sensitivity can advance our understanding of the processes that lead to addiction. Phenotyping inbred mouse strain panels are frequently used as a first step for studying the genetic architecture of complex traits. We assessed locomotor activation following a single, acute 20 mg/kg dose of cocaine (COC) in males from 45 inbred mouse strains and observed significant phenotypic variation across strains indicating a substantial genetic component. We also measured levels of COC, the active metabolite, norcocaine and the major inactive metabolite, benzoylecgonine, in plasma and brain in the same set of inbred strains. Pharmacokinetic (PK) and behavioral data were significantly correlated, but at a level that indicates that PK alone does not account for the behavioral differences observed across strains. Phenotypic data from this reference population of inbred strains can be utilized in studies aimed at examining the role of psychostimulant-induced locomotor activation on drug reward and reinforcement and to test theories about addiction processes. Moreover, these data serve as a starting point for identifying genes that alter sensitivity to the locomotor stimulatory effects of COC. PMID:25727211

  15. Initial locomotor sensitivity to cocaine varies widely among inbred mouse strains

    PubMed Central

    Wiltshire, T.; Ervin, R. B.; Duan, H.; Bogue, M. A.; Zamboni, W. C.; Cook, S.; Chung, W.; Zou, F.; Tarantino, L. M.

    2015-01-01

    Initial sensitivity to psychostimulants can predict subsequent use and abuse in humans. Acute locomotor activation in response to psychostimulants is commonly used as an animal model of initial drug sensitivity and has been shown to have a substantial genetic component. Identifying the specific genetic differences that lead to phenotypic differences in initial drug sensitivity can advance our understanding of the processes that lead to addiction. Phenotyping inbred mouse strain panels are frequently used as a first step for studying the genetic architecture of complex traits. We assessed locomotor activation following a single, acute 20 mg/kg dose of cocaine (COC) in males from 45 inbred mouse strains and observed significant phenotypic variation across strains indicating a substantial genetic component. We also measured levels of COC, the active metabolite, norcocaine and the major inactive metabolite, benzoylecgonine, in plasma and brain in the same set of inbred strains. Pharmacokinetic (PK) and behavioral data were significantly correlated, but at a level that indicates that PK alone does not account for the behavioral differences observed across strains. Phenotypic data from this reference population of inbred strains can be utilized in studies aimed at examining the role of psychostimulant-induced locomotor activation on drug reward and reinforcement and to test theories about addiction processes. Moreover, these data serve as a starting point for identifying genes that alter sensitivity to the locomotor stimulatory effects of COC. PMID:25727211

  16. The GALS locomotor screen and disability.

    PubMed Central

    Plant, M J; Linton, S; Dodd, E; Jones, P W; Dawes, P T

    1993-01-01

    OBJECTIVES--Examination of the locomotor system is frequently neglected. Therefore, the GALS locomotor screen (Gait, Arms, Legs, Spine) has been proposed by Doherty et al as a practical method of identifying functionally important problems. This study was designed to test whether this screen reflects functional impairment, as measured by accepted health status measures. METHODS--Two observers performed the GALS screen in a total of 83 patients with a variety of musculoskeletal conditions. The examination components of GALS were rated by a simple 0 to 3 scale. Physical ability was further assessed by Health Activity Questionnaire (HAQ), Barthel index and Steinbrocker's ARA classification. RESULTS--For the total patient group, Spearman correlations between GALS and the three functional indices were good (r = 0.62 to 0.71, p < 0.001). Correlations were equally good for rheumatoid arthritis patients alone (r = 0.65 to 0.70, p < 0.001), but less good although still significant for the other miscellaneous rheumatic conditions (r = 0.31 to 0.46, p < 0.05). Observed proportional agreement between the two observers for the individual scores was > 70%, with a kappa statistic k = 0.49 to 0.74. CONCLUSIONS--The GALS screen is a reliable and valid measure of functional ability, compared with standard accepted indices in a variety of musculoskeletal diseases. This supports the proposal for its use as a screening test by general practitioners and medical students. PMID:8311541

  17. Dynamic Control of Posture Across Locomotor Tasks

    PubMed Central

    Earhart, Gammon M.

    2013-01-01

    Successful locomotion depends on postural control to establish and maintain appropriate postural orientation of body segments relative to one another and to the environment, and to ensure dynamic stability of the moving body. This paper provides a framework for considering dynamic postural control, highlighting the importance of coordination, consistency, and challenges to postural control posed by various locomotor tasks such as turning and backward walking. The impacts of aging and various movement disorders on postural control are discussed broadly in an effort to provide a general overview of the field and recommendations for assessment of dynamic postural control across different populations in both clinical and research settings. Suggestions for future research on dynamic postural control during locomotion are also provided and include discussion of opportunities afforded by new and developing technologies, the need for long-term monitoring of locomotor performance in everyday activities, gaps in our knowledge of how targeted intervention approaches modify dynamic postural control, and the relative paucity of literature regarding dynamic postural control in movement disorder populations other than Parkinson disease. PMID:24132838

  18. Development of a spinal locomotor rheostat.

    PubMed

    Zhang, Hong-Yan; Issberner, Jon; Sillar, Keith T

    2011-07-12

    Locomotion in immature animals is often inflexible, but gradually acquires versatility to enable animals to maneuver efficiently through their environment. Locomotor activity in adults is produced by complex spinal cord networks that develop from simpler precursors. How does complexity and plasticity emerge during development to bestow flexibility upon motor behavior? And how does this complexity map onto the peripheral innervation fields of motorneurons during development? We show in postembryonic Xenopus laevis frog tadpoles that swim motorneurons initially form a homogenous pool discharging single action potential per swim cycle and innervating most of the dorsoventral extent of the swimming muscles. However, during early larval life, in the prelude to a free-swimming existence, the innervation fields of motorneurons become restricted to a more limited sector of each muscle block, with individual motorneurons reaching predominantly ventral, medial, or dorsal regions. Larval motorneurons then can also discharge multiple action potentials in each cycle of swimming and differentiate in terms of their firing reliability during swimming into relatively high-, medium-, or low-probability members. Many motorneurons fall silent during swimming but can be recruited with increasing locomotor frequency and intensity. Each region of the myotome is served by motorneurons spanning the full range of firing probabilities. This unfolding developmental plan, which occurs in the absence of movement, probably equips the organism with the neuronal substrate to bend, pitch, roll, and accelerate during swimming in ways that will be important for survival during the period of free-swimming larval life that ensues. PMID:21709216

  19. Both novelty and expertise increase action observation network activity

    PubMed Central

    Liew, Sook-Lei; Sheng, Tong; Margetis, John L.; Aziz-Zadeh, Lisa

    2013-01-01

    Our experiences with others affect how we perceive their actions. In particular, activity in bilateral premotor and parietal cortices during action observation, collectively known as the action observation network (AON), is modulated by one's expertise with the observed actions or individuals. However, conflicting reports suggest that AON activity is greatest both for familiar and unfamiliar actions. The current study examines the effects of different types and amounts of experience (e.g., visual, interpersonal, personal) on AON activation. fMRI was used to scan 16 healthy participants without prior experience with individuals with amputations (novices), 11 experienced occupational therapists (OTs) who had varying amounts of experience with individuals with amputations, and one individual born with below-elbow residual limbs (participant CJ), as they viewed video clips of goal-matched actions performed by an individual with residual limbs and by an individual with hands. Participants were given increased visual exposure to actions performed by both effectors midway through the scanning procedure. Novices demonstrated a large AON response to the initial viewing of an individual with residual limbs compared to one with hands, but this signal was attenuated after they received visual exposure to both effectors. In contrast, OTs, who had moderate familiarity with residual limbs, demonstrated a lower AON response upon initial viewing—similar to novices after they received visual exposure. At the other extreme, CJ, who has extreme familiarity with residual limbs both visually and motorically, shows a largely increased left-lateralized AON response, exceeding that of novices and experienced OTs, when viewing the residual limb compared to hand actions. These results suggest that a nuanced model of AON engagement is needed to explain how cases of both extreme experience (CJ) and extreme novelty (novices) can result in the greatest AON activity. PMID:24062656

  20. Quantitative Trait Loci for Locomotor Behavior in Drosophila melanogaster

    PubMed Central

    Jordan, Katherine W.; Morgan, Theodore J.; Mackay, Trudy F. C.

    2006-01-01

    Locomotion is an integral component of most animal behaviors and many human diseases and disorders are associated with locomotor deficits, but little is known about the genetic basis of natural variation in locomotor behavior. Locomotion is a complex trait, with variation attributable to the joint segregation of multiple interacting quantitative trait loci (QTL), with effects that are sensitive to the environment. We assessed variation in a component of locomotor behavior (locomotor reactivity) in a population of 98 recombinant inbred lines of Drosophila melanogaster and mapped four QTL affecting locomotor reactivity by linkage to polymorphic roo transposable element insertion sites. We used complementation tests of deficiencies to fine map these QTL to 12 chromosomal regions and complementation tests of mutations to identify 13 positional candidate genes affecting locomotor reactivity, including Dopa decarboxylase (Ddc), which catalyzes the final step in the synthesis of serotonin and dopamine. Linkage disequilibrium mapping in a population of 164 second chromosome substitution lines derived from a single natural population showed that polymorphisms at Ddc were associated with naturally occurring genetic variation in locomotor behavior. These data implicate variation in the synthesis of bioamines as a factor contributing to natural variation in locomotor reactivity. PMID:16783013

  1. Locomotor Behaviour of Blattella germanica Modified by DEET

    PubMed Central

    Sfara, Valeria; Mougabure-Cueto, Gastón A.; Zerba, Eduardo N.; Alzogaray, Raúl A.

    2013-01-01

    N,N-diethyl-3-methylbenzamide (DEET) is the active principle of most insect repellents used worldwide. However, its toxicity on insects has not been widely studied. The aim of this work is to study the effects of DEET on the locomotor activity of Blattella germanica. DEET has a dose-dependent repellent activity on B. germanica. Locomotor activity was significantly lower when insects were pre-exposed to 700 µg/cm2 of DEET for 20 or 30 minutes, but it did not change when pre-exposure was shorter. Locomotor activity of insects that were pre-exposed to 2.000 µg/cm2 of DEET for 10 minutes was significantly lower than the movement registered in controls. No differences were observed when insects were pre-exposed to lower concentrations of DEET. A 30-minute pre-exposure to 700 µg/cm2 of DEET caused a significant decrease in locomotor activity. Movement was totally recovered 24 h later. The locomotor activity measured during the exposure to different concentrations of DEET remained unchanged. Insects with decreased locomotor activity were repelled to the same extent than control insects by the same concentration of DEET. We demonstrated that the repellency and modification of locomotor activity elicited by DEET are non-associated phenomena. We also suggested that the reduction in locomotor activity indicates toxicity of DEET, probably to insect nervous system. PMID:24376701

  2. Locomotor behaviour of Blattella germanica modified by DEET.

    PubMed

    Sfara, Valeria; Mougabure-Cueto, Gastón A; Zerba, Eduardo N; Alzogaray, Raúl A

    2013-01-01

    N,N-diethyl-3-methylbenzamide (DEET) is the active principle of most insect repellents used worldwide. However, its toxicity on insects has not been widely studied. The aim of this work is to study the effects of DEET on the locomotor activity of Blattella germanica. DEET has a dose-dependent repellent activity on B. germanica. Locomotor activity was significantly lower when insects were pre-exposed to 700 µg/cm(2) of DEET for 20 or 30 minutes, but it did not change when pre-exposure was shorter. Locomotor activity of insects that were pre-exposed to 2.000 µg/cm(2) of DEET for 10 minutes was significantly lower than the movement registered in controls. No differences were observed when insects were pre-exposed to lower concentrations of DEET. A 30-minute pre-exposure to 700 µg/cm(2) of DEET caused a significant decrease in locomotor activity. Movement was totally recovered 24 h later. The locomotor activity measured during the exposure to different concentrations of DEET remained unchanged. Insects with decreased locomotor activity were repelled to the same extent than control insects by the same concentration of DEET. We demonstrated that the repellency and modification of locomotor activity elicited by DEET are non-associated phenomena. We also suggested that the reduction in locomotor activity indicates toxicity of DEET, probably to insect nervous system. PMID:24376701

  3. Effect of caffeine on cocaine locomotor stimulant activity in rats.

    PubMed

    Misra, A L; Vadlamani, N L; Pontani, R B

    1986-03-01

    The effect of caffeine on the locomotor stimulant activity induced by intravenous cocaine in rats was investigated. Low doses of caffeine (20 mg/kg IP) potentiated the locomotor activity induced by 1, 2.5 mg/kg intravenous doses of cocaine and higher doses of caffeine (50, 100 mg/kg IP) had no significant effect. The locomotor stimulant effect of 20 mg/kg IP dose of caffeine per se in vehicle was significantly higher and that with 100 mg/kg dose significantly lower than that of the vehicle control. Thus caffeine produced dose-dependent effects on cocaine-induced locomotor stimulant activity, with low dose potentiating and higher doses having no significant effect on such activity. Pharmacokinetic or dispositional factors did not appear to play a role in potentiation of cocaine locomotor stimulant activity by caffeine. PMID:3703910

  4. Novelty and Innovation in the History of Life.

    PubMed

    Erwin, Douglas H

    2015-10-01

    The history of life as documented by the fossil record encompasses evolutionary diversifications at scales ranging from the Ediacaran-Cambrian explosion of animal life and the invasion of land by vascular plants, insects and vertebrates to the diversification of flowering plants over the past 100 million years and the radiation of horses. Morphological novelty and innovation has been a recurrent theme. The architects of the modern synthesis of evolutionary theory made three claims about evolutionary novelty and innovation: first, that all diversifications in the history of life represent adaptive radiations; second, that adaptive radiations are driven principally by ecological opportunity rather than by the supply of new morphological novelties, thus the primary questions about novelty and innovation focus on their ecological and evolutionary success; and third, that the rate of morphological divergence between taxa was more rapid early in the history of a clade but slowed over time as ecological opportunities declined. These claims have strongly influenced subsequent generations of evolutionary biologists, yet over the past two decades each has been challenged by data from the fossil record, by the results of comparative phylogenetic analyses and through insights from evolutionary developmental biology. Consequently a broader view of novelty and innovation is required. An outstanding issue for future work is identifying the circumstances associated with different styles of diversification and whether their frequency has changed through the history of life. PMID:26439356

  5. Functional Reorganization of the Locomotor Network in Parkinson Patients with Freezing of Gait

    PubMed Central

    Fling, Brett W.; Cohen, Rajal G.; Mancini, Martina; Carpenter, Samuel D.; Fair, Damien A.; Nutt, John G.; Horak, Fay B.

    2014-01-01

    Freezing of gait (FoG) is a transient inability to initiate or maintain stepping that often accompanies advanced Parkinson’s disease (PD) and significantly impairs mobility. The current study uses a multimodal neuroimaging approach to assess differences in the functional and structural locomotor neural network in PD patients with and without FoG and relates these findings to measures of FoG severity. Twenty-six PD patients and fifteen age-matched controls underwent resting-state functional magnetic resonance imaging and diffusion tensor imaging along with self-reported and clinical assessments of FoG. After stringent movement correction, fifteen PD patients and fourteen control participants were available for analysis. We assessed functional connectivity strength between the supplementary motor area (SMA) and the following locomotor hubs: 1) subthalamic nucleus (STN), 2) mesencephalic and 3) cerebellar locomotor region (MLR and CLR, respectively) within each hemisphere. Additionally, we quantified structural connectivity strength between locomotor hubs and assessed relationships with metrics of FoG. FoG+ patients showed greater functional connectivity between the SMA and bilateral MLR and between the SMA and left CLR compared to both FoG− and controls. Importantly, greater functional connectivity between the SMA and MLR was positively correlated with i) clinical, ii) self-reported and iii) objective ratings of freezing severity in FoG+, potentially reflecting a maladaptive neural compensation. The current findings demonstrate a re-organization of functional communication within the locomotor network in FoG+ patients whereby the higher-order motor cortex (SMA) responsible for gait initiation communicates with the MLR and CLR to a greater extent than in FoG− patients and controls. The observed pattern of altered connectivity in FoG+ may indicate a failed attempt by the CNS to compensate for the loss of connectivity between the STN and SMA and may reflect a loss

  6. Male rats that differ in novelty exploration demonstrate distinct patterns of sexual behavior

    PubMed Central

    Cummings, Jennifer A.; Clinton, Sarah M.; Perry, Adam N.; Akil, Huda; Becker, Jill B.

    2014-01-01

    High versus low novelty exploration predicts a variety of behavioral differences. For example, rats selectively-bred for high novelty exploration (bred High Responders, bHR) exhibit exaggerated aggression, impulsivity, and proclivity to addictive behaviors compared to low novelty-reactive rats (bred Low Responders, bLRs), which are characterized by a high anxiety/depressive-like phenotype. Since bHR/bLR rats exhibit differences in dopaminergic circuitry and differential response to rewarding stimuli (i.e., psychostimulants, food), the present study examined whether they also differ in another key hedonic behavior – sex. Thus, adult bHR/bLR males were given five 30-min opportunities to engage in sexual activity with a receptive female. Sexual behavior and motivation were examined and compared between the groups. The bHR/bLR phenotype affected both sexual motivation and behavior, with bLR males demonstrating reduced motivation for sex compared with bHR males (i.e., fewer animals copulated, longer latency to engage in sex). The bHR males required more intromissions at a faster pace per ejaculation than did bLR males. Thus, neurobiological differences that affect motivation for drugs of abuse, aggression, and impulsivity in rats also affect sexual motivation and performance. PMID:23398441

  7. Fast support vector data descriptions for novelty detection.

    PubMed

    Liu, Yi-Hung; Liu, Yan-Chen; Chen, Yen-Jen

    2010-08-01

    Support vector data description (SVDD) has become a very attractive kernel method due to its good results in many novelty detection problems. However, the decision function of SVDD is expressed in terms of the kernel expansion, which results in a run-time complexity linear in the number of support vectors. For applications where fast real-time response is needed, how to speed up the decision function is crucial. This paper aims at dealing with the issue of reducing the testing time complexity of SVDD. A method called fast SVDD (F-SVDD) is proposed. Unlike the traditional methods which all try to compress a kernel expansion into one with fewer terms, the proposed F-SVDD directly finds the preimage of a feature vector, and then uses a simple relationship between this feature vector and the SVDD sphere center to re-express the center with a single vector. The decision function of F-SVDD contains only one kernel term, and thus the decision boundary of F-SVDD is only spherical in the original space. Hence, the run-time complexity of the F-SVDD decision function is no longer linear in the support vectors, but is a constant, no matter how large the training set size is. In this paper, we also propose a novel direct preimage-finding method, which is noniterative and involves no free parameters. The unique preimage can be obtained in real time by the proposed direct method without taking trial-and-error. For demonstration, several real-world data sets and a large-scale data set, the extended MIT face data set, are used in experiments. In addition, a practical industry example regarding liquid crystal display micro-defect inspection is also used to compare the applicability of SVDD and our proposed F-SVDD when faced with mass data input. The results are very encouraging. PMID:20639178

  8. Evidence That GABA Mediates Dopaminergic and Serotonergic Pathways Associated with Locomotor Activity in Juvenile Chinook Salmon (Oncorhynchus tshawytscha)

    USGS Publications Warehouse

    Clements, S.; Schreck, C.B.

    2004-01-01

    The authors examined the control of locomotor activity in juvenile salmon (Oncorhynchus tshawytscha) by manipulating 3 neurotransmitter systems-gamma-amino-n-butyric acid (GABA), dopamine, and serotonin-as well as the neuropeptide corticotropin releasing hormone (CRH). Intracerebroventricular (ICV) injections of CRH and the GABAAagonist muscimol stimulated locomotor activity. The effect of muscimol was attenuated by administration of a dopamine receptor antagonist, haloperidol. Conversely, the administration of a dopamine uptake inhibitor (4???,4??? -difluoro-3-alpha-[diphenylmethoxy] tropane hydrochloride [DUI]) potentiated the effect of muscimol. They found no evidence that CRH-induced hyperactivity is mediated by dopaminergic systems following concurrent injections of haloperidol or DUI with CRH. Administration of muscimol either had no effect or attenuated the locomotor response to concurrent injections of CRH and fluoxetine, whereas the GABAA antagonist bicuculline methiodide potentiated the effect of CRH and fluoxetine.

  9. Dose-dependent changes in the synaptic strength on dopamine neurons and locomotor activity after cocaine exposure

    PubMed Central

    Wanat, M.J.; Bonci, A.

    2016-01-01

    Changes in synaptic strength on ventral tegmental area (VTA) dopamine neurons are thought to play a critical role in the development of addiction-related behaviors. However, it is unknown how a single injection of cocaine at different doses affects locomotor activity, behavioral sensitization, and glutamatergic synaptic strength on VTA dopamine neurons in mice. We observed that behavioral sensitization to a challenge cocaine injection scaled with the dose of cocaine received one day prior. Interestingly, the locomotor activity after the initial exposure to different doses of cocaine corresponded to the changes in glutamatergic strength on VTA dopamine neurons. These results in mice suggest that a single exposure to cocaine dose-dependently affects excitatory synapses on VTA dopamine neurons, and that this acute synaptic alteration is directly associated with the locomotor responses to cocaine and not to behavioral sensitization. PMID:18655120

  10. Prenatal Cocaine Exposure and Infants' Preference for Novelty and Distractibility

    ERIC Educational Resources Information Center

    Gaultney, Jane F.; Gingras, Jeannine L.; Martin, Mindy; DeBrule, Daniel

    2005-01-01

    The authors used the Fagan Test of Infant Intelligence (J. F. Fagan, L. T. Singer, J. E. Montie, & P. A. Shepherd, 1986) to examine preferences for novelty and to evaluate several indicators of attention (off- and on-task indexes and durations) in 6- and 9-month-old infants who had been prenatally exposed to cigarette smoke only or to cocaine plus…

  11. Emergent Novelties in the Mentality of Dizygotic Twins.

    ERIC Educational Resources Information Center

    Bierschenk, Bernhard

    Scanator is an extremely valuable tool in the functional analysis of qualitative stability in text building behavior during writing. Scanator also allows for a detailed investigation of subtle changes emerging in the structural relations of emergent novelties. This study focused on the extension of the application of Scanator to one pair of…

  12. Secondary contact seeds phenotypic novelty in cichlid fishes

    PubMed Central

    Nichols, Paul; Genner, Martin J.; van Oosterhout, Cock; Smith, Alan; Parsons, Paul; Sungani, Harold; Swanstrom, Jennifer; Joyce, Domino A.

    2015-01-01

    Theory proposes that genomic admixture between formerly reproductively isolated populations can generate phenotypic novelty for selection to act upon. Secondary contact may therefore be a significant promoter of phenotypic novelty that allows species to overcome environmental challenges and adapt to novel environments, including during adaptive radiation. To date, this has largely been considered from the perspective of interspecific hybridization at contact zones. However, it is also possible that this process occurs more commonly between natural populations of a single species, and thus its importance in adaptive evolution may have been underestimated. In this study, we tested the consequences of genomic introgression during apparent secondary contact between phenotypically similar lineages of the riverine cichlid fish Astatotilapia calliptera. We provide population genetic evidence of a secondary contact zone in the wild, and then demonstrate using mate-choice experiments that both lineages can reproduce together successfully in laboratory conditions. Finally, we show that genomically admixed individuals display extreme phenotypes not observed in the parental lineages. Collectively, the evidence shows that secondary contact can drive the evolution of phenotypic novelty, suggesting that pulses of secondary contact may repeatedly seed genetic novelty, which when coupled with ecological opportunity could promote rapid adaptive evolution in natural circumstances. PMID:25392475

  13. Broken Expectations: Violation of Expectancies, Not Novelty, Captures Auditory Attention

    ERIC Educational Resources Information Center

    Vachon, Francois; Hughes, Robert W.; Jones, Dylan M.

    2012-01-01

    The role of memory in behavioral distraction by auditory attentional capture was investigated: We examined whether capture is a product of the novelty of the capturing event (i.e., the absence of a recent memory for the event) or its violation of learned expectancies on the basis of a memory for an event structure. Attentional capture--indicated…

  14. Secondary contact seeds phenotypic novelty in cichlid fishes.

    PubMed

    Nichols, Paul; Genner, Martin J; van Oosterhout, Cock; Smith, Alan; Parsons, Paul; Sungani, Harold; Swanstrom, Jennifer; Joyce, Domino A

    2015-01-01

    Theory proposes that genomic admixture between formerly reproductively isolated populations can generate phenotypic novelty for selection to act upon. Secondary contact may therefore be a significant promoter of phenotypic novelty that allows species to overcome environmental challenges and adapt to novel environments, including during adaptive radiation. To date, this has largely been considered from the perspective of interspecific hybridization at contact zones. However, it is also possible that this process occurs more commonly between natural populations of a single species, and thus its importance in adaptive evolution may have been underestimated. In this study, we tested the consequences of genomic introgression during apparent secondary contact between phenotypically similar lineages of the riverine cichlid fish Astatotilapia calliptera. We provide population genetic evidence of a secondary contact zone in the wild, and then demonstrate using mate-choice experiments that both lineages can reproduce together successfully in laboratory conditions. Finally, we show that genomically admixed individuals display extreme phenotypes not observed in the parental lineages. Collectively, the evidence shows that secondary contact can drive the evolution of phenotypic novelty, suggesting that pulses of secondary contact may repeatedly seed genetic novelty, which when coupled with ecological opportunity could promote rapid adaptive evolution in natural circumstances. PMID:25392475

  15. The role of novelty in early word learning.

    PubMed

    Mather, Emily; Plunkett, Kim

    2012-01-01

    What mechanism implements the mutual exclusivity bias to map novel labels to objects without names? Prominent theoretical accounts of mutual exclusivity (e.g., Markman, 1989, 1990) propose that infants are guided by their knowledge of object names. However, the mutual exclusivity constraint could be implemented via monitoring of object novelty (see Merriman, Marazita, & Jarvis, 1995). We sought to discriminate between these contrasting explanations across two preferential looking experiments with 22-month-olds. In Experiment 1, infants viewed three objects: one name-known, two name-unknown. Of the two name-unknown objects, one was novel, and the other had been previously familiarized. The infants responded to hearing a novel label by increasing attention only to the novel, name-unknown object. In a second experiment in which the name-known object was absent, a novel label increased infants' attention to a novel object beyond baseline preference for novelty. The experiments provide clear evidence for a novelty-based mechanism. However, differences in the time course of disambiguation across experiments suggest that novelty processing may be influenced by contextual factors. PMID:22436081

  16. Manipulation and Novelty of Reward as Features in Educational Games.

    ERIC Educational Resources Information Center

    Keislar, Evan R.; Phinney, Jean

    This experimental study investigates differences between a game approach and a programmed learning approach in teaching three listening comprehension skills (negation, exclusion, joint denial) to a total of 13 4- or 5-year-old Head Start children. It was hypothesized that (1) manipulation and novelty of reward would influence children to choose an…

  17. Evidence for a Role of Orexin/Hypocretin System in Vestibular Lesion-Induced Locomotor Abnormalities in Rats

    PubMed Central

    Pan, Leilei; Qi, Ruirui; Wang, Junqin; Zhou, Wei; Liu, Jiluo; Cai, Yiling

    2016-01-01

    Vestibular damage can induce locomotor abnormalities in both animals and humans. Rodents with bilateral vestibular loss showed vestibular deficits syndrome such as circling, opisthotonus as well as locomotor and exploratory hyperactivity. Previous studies have investigated the changes in the dopamine system after vestibular loss, but the results are inconsistent and inconclusive. Numerous evidences indicate that the orexin system is implicated in central motor control. We hypothesized that orexin may be potentially involved in vestibular loss-induced motor disorders. In this study, we examined the effects of arsanilate- or 3,3′-iminodipropionitrile (IDPN)-induced vestibular lesion (AVL or IVL) on the orexin-A (OXA) labeling in rat hypothalamus using immunohistochemistry. The vestibular lesion-induced locomotor abnormalities were recorded and verified using a histamine H4 receptor antagonist JNJ7777120 (20 mg/kg, i.p.). The effects of the orexin receptor type 1 antagonist SB334867 (16 μg, i.c.v.) on these behavior responses were also investigated. At 72 h post-AVL and IVL, animals exhibited vestibular deficit syndrome and locomotor hyperactivity in the home cages. These responses were significantly alleviated by JNJ7777120 which also eliminated AVL-induced increases in exploratory behavior in an open field. The numbers of OXA-labeled neurons in the hypothalamus were significantly increased in the AVL animals at 72 h post-AVL and in the IVL animals at 24, 48, and 72 h post-IVL. SB334867 significantly attenuated the vestibular deficit syndrome and locomotor hyperactivity at 72 h post-AVL and IVL. It also decreased exploratory behavior in the AVL animals. These results suggested that the alteration of OXA expression might contribute to locomotor abnormalities after acute vestibular lesion. The orexin receptors might be the potential therapeutic targets for vestibular disorders. PMID:27507932

  18. Evidence for a Role of Orexin/Hypocretin System in Vestibular Lesion-Induced Locomotor Abnormalities in Rats.

    PubMed

    Pan, Leilei; Qi, Ruirui; Wang, Junqin; Zhou, Wei; Liu, Jiluo; Cai, Yiling

    2016-01-01

    Vestibular damage can induce locomotor abnormalities in both animals and humans. Rodents with bilateral vestibular loss showed vestibular deficits syndrome such as circling, opisthotonus as well as locomotor and exploratory hyperactivity. Previous studies have investigated the changes in the dopamine system after vestibular loss, but the results are inconsistent and inconclusive. Numerous evidences indicate that the orexin system is implicated in central motor control. We hypothesized that orexin may be potentially involved in vestibular loss-induced motor disorders. In this study, we examined the effects of arsanilate- or 3,3'-iminodipropionitrile (IDPN)-induced vestibular lesion (AVL or IVL) on the orexin-A (OXA) labeling in rat hypothalamus using immunohistochemistry. The vestibular lesion-induced locomotor abnormalities were recorded and verified using a histamine H4 receptor antagonist JNJ7777120 (20 mg/kg, i.p.). The effects of the orexin receptor type 1 antagonist SB334867 (16 μg, i.c.v.) on these behavior responses were also investigated. At 72 h post-AVL and IVL, animals exhibited vestibular deficit syndrome and locomotor hyperactivity in the home cages. These responses were significantly alleviated by JNJ7777120 which also eliminated AVL-induced increases in exploratory behavior in an open field. The numbers of OXA-labeled neurons in the hypothalamus were significantly increased in the AVL animals at 72 h post-AVL and in the IVL animals at 24, 48, and 72 h post-IVL. SB334867 significantly attenuated the vestibular deficit syndrome and locomotor hyperactivity at 72 h post-AVL and IVL. It also decreased exploratory behavior in the AVL animals. These results suggested that the alteration of OXA expression might contribute to locomotor abnormalities after acute vestibular lesion. The orexin receptors might be the potential therapeutic targets for vestibular disorders. PMID:27507932

  19. Dynamic Locomotor Capabilities Revealed by Early Dinosaur Trackmakers from Southern Africa

    PubMed Central

    Wilson, Jeffrey A.; Marsicano, Claudia A.; Smith, Roger M. H.

    2009-01-01

    Background A new investigation of the sedimentology and ichnology of the Early Jurassic Moyeni tracksite in Lesotho, southern Africa has yielded new insights into the behavior and locomotor dynamics of early dinosaurs. Methodology/Principal Findings The tracksite is an ancient point bar preserving a heterogeneous substrate of varied consistency and inclination that includes a ripple-marked riverbed, a bar slope, and a stable algal-matted bar top surface. Several basal ornithischian dinosaurs and a single theropod dinosaur crossed its surface within days or perhaps weeks of one another, but responded to substrate heterogeneity differently. Whereas the theropod trackmaker accommodated sloping and slippery surfaces by gripping the substrate with its pedal claws, the basal ornithischian trackmakers adjusted to the terrain by changing between quadrupedal and bipedal stance, wide and narrow gauge limb support (abduction range = 31°), and plantigrade and digitigrade foot posture. Conclusions/Significance The locomotor adjustments coincide with changes in substrate consistency along the trackway and appear to reflect ‘real time’ responses to a complex terrain. It is proposed that these responses foreshadow important locomotor transformations characterizing the later evolution of the two main dinosaur lineages. Ornithischians, which shifted from bipedal to quadrupedal posture at least three times in their evolutionary history, are shown to have been capable of adopting both postures early in their evolutionary history. The substrate-gripping behavior demonstrated by the early theropod, in turn, is consistent with the hypothesized function of pedal claws in bird ancestors. PMID:19806213

  20. High Novelty-Seeking Rats Are Resilient to Negative Physiological Effects of the Early Life Stress

    PubMed Central

    Clinton, Sarah M.; Watson, Stanley J.; Akil, Huda

    2014-01-01

    Exposure to early life stress dramatically impacts adult behavior, physiology, and neuroendocrine function. Using rats bred for novelty-seeking differences and known to display divergent anxiety, depression, and stress vulnerability, we examined the interaction between early life adversity and genetic predisposition for high- versus low-emotional reactivity. Thus, bred Low Novelty Responder (bLR) rats, which naturally exhibit high anxiety- and depression-like behavior, and bred High Novelty Responder (bHR) rats, which show low anxiety/depression together with elevated aggression, impulsivity, and addictive behavior, were subjected to daily 3 h maternal separation (MS) stress postnatal days 1–14. We hypothesized that MS stress would differentially impact adult bHR/bLR behavior, physiology (stress-induced defecation), and neuroendocrine reactivity. While MS stress did not impact bHR and bLR anxiety-like behavior in the open field test and elevated plus maze, it exacerbated bLRs’ already high physiological response to stress – stress-induced defecation. In both tests, MS bLR adult offspring showed exaggerated stress-induced defecation compared to bLR controls while bHR offspring were unaffected. MS also selectively impacted bLRs’ (but not bHRs’) neuroendocrine stress reactivity, producing an exaggerated corticosterone acute stress response in MS bLR versus control bLR rats. These findings highlight how genetic predisposition shapes individuals’ response to early life stress. Future work will explore neural mechanisms underlying the distinct behavioral and neuroendocrine consequences of MS in bHR/bLR animals. PMID:24090131

  1. Reliability review of the remote tool delivery system locomotor

    SciTech Connect

    Chesser, J.B.

    1999-04-01

    The locomotor being built by RedZone Robotics is designed to serve as a remote tool delivery (RID) system for waste retrieval, tank cleaning, viewing, and inspection inside the high-level waste tanks 8D-1 and 8D-2 at West Valley Nuclear Services (WVNS). The RTD systm is to be deployed through a tank riser. The locomotor portion of the RTD system is designed to be inserted into the tank and is to be capable of moving around the tank by supporting itself and moving on the tank internal structural columns. The locomotor will serve as a mounting platform for a dexterous manipulator arm. The complete RTD system consists of the locomotor, dexterous manipulator arm, cameras, lights, cables, hoses, cable/hose management system, power supply, and operator control station.

  2. Locomotor stereotypy produced by dexbenzetimide and scopolamine is reduced by SKF 83566, not sulpiride.

    PubMed

    Fritts, M E; Mueller, K; Morris, L

    1998-07-01

    Like amphetamine, scopolamine produces locomotor stereotypy (repetitive routes of locomotion) in an open field. To determine whether locomotor stereotypy is a common behavioral effect of anticholingeric agents, several doses of the anticholinergic dexbenzetimide were tested for the ability to produce locomotor stereotypy; like scopolamine, dexbenzetimide produced locomotor stereotypy. To investigate a possible role of dopamine in anticholinergic-induced locomotor stereotypy, we tested the ability of the dopamine D1 antagonist SKF 83566 and the D2 antagonist sulpiride to block the locomotor stereotypy induced by scopolamine as well as dexbenzetimide. SKF 83566 blocked scopolamine- and dexbenzetimide-induced locomotor stereotypy; sulpiride did not reduce dexbenzetimide-induced locomotor stereotypy, but enhanced scopolamine-induced locomotor stereotypy. Hyperlocomotion was reduced by both dopamine antagonists. Results are interpreted in support of the notion that dopamine is the likely candidate mediating locomotor stereotypy. PMID:9678647

  3. Event-Related Potential, Time-frequency, and Functional Connectivity Facets of Local and Global Auditory Novelty Processing: An Intracranial Study in Humans.

    PubMed

    El Karoui, Imen; King, Jean-Remi; Sitt, Jacobo; Meyniel, Florent; Van Gaal, Simon; Hasboun, Dominique; Adam, Claude; Navarro, Vincent; Baulac, Michel; Dehaene, Stanislas; Cohen, Laurent; Naccache, Lionel

    2015-11-01

    Auditory novelty detection has been associated with different cognitive processes. Bekinschtein et al. (2009) developed an experimental paradigm to dissociate these processes, using local and global novelty, which were associated, respectively, with automatic versus strategic perceptual processing. They have mostly been studied using event-related potentials (ERPs), but local spiking activity as indexed by gamma (60-120 Hz) power and interactions between brain regions as indexed by modulations in beta-band (13-25 Hz) power and functional connectivity have not been explored. We thus recorded 9 epileptic patients with intracranial electrodes to compare the precise dynamics of the responses to local and global novelty. Local novelty triggered an early response observed as an intracranial mismatch negativity (MMN) contemporary with a strong power increase in the gamma band and an increase in connectivity in the beta band. Importantly, all these responses were strictly confined to the temporal auditory cortex. In contrast, global novelty gave rise to a late ERP response distributed across brain areas, contemporary with a sustained power decrease in the beta band (13-25 Hz) and an increase in connectivity in the alpha band (8-13 Hz) within the frontal lobe. We discuss these multi-facet signatures in terms of conscious access to perceptual information. PMID:24969472

  4. Aesthetic Emotions and Aesthetic People: Openness Predicts Sensitivity to Novelty in the Experiences of Interest and Pleasure

    PubMed Central

    Fayn, Kirill; MacCann, Carolyn; Tiliopoulos, Niko; Silvia, Paul J.

    2015-01-01

    There is a stable relationship between the Openness/Intellect domain of personality and aesthetic engagement. However, neither of these are simple constructs and while the relationship exists, process based evidence explaining the relationship is still lacking. This research sought to clarify the relationship by evaluating the influence of the Openness and Intellect aspects on several different aesthetic emotions. Two studies looked at the between- and within-person differences in arousal and the emotions of interest, pleasure and confusion in response to visual art. The results suggest that Openness, as opposed to Intellect, was predictive of greater arousal, interest and pleasure, while both aspects explained less confusion. Differences in Openness were associated with within-person emotion appraisal contingencies, particularly greater novelty-interest and novelty-pleasure relationships. Those higher in Openness were particularly influenced by novelty in artworks. For pleasure this relationship suggested a different qualitative structure of appraisals. The appraisal of novelty is part of the experience of pleasure for those high in Openness, but not those low in Openness. This research supports the utility of studying Openness and Intellect as separate aspects of the broad domain and clarifies the relationship between Openness and aesthetic states in terms of within-person appraisal processes. PMID:26696940

  5. EEG delta oscillations index inhibitory control of contextual novelty to both irrelevant distracters and relevant task-switch cues.

    PubMed

    Prada, Laura; Barceló, Francisco; Herrmann, Christoph S; Escera, Carles

    2014-07-01

    Delta oscillations contribute to the human P300 event-related potential evoked by oddball targets, although it is unclear whether they index contextual novelty (event oddballness, novelty P3, nP3), or target-related processes (event targetness, target P3b). To examine this question, the electroencephalogram (EEG) was recorded during a cued task-switching version of the Wisconsin card-sorting test. Each target card was announced by a tone cueing either to switch or repeat the task. Novel sound distracters were interspersed among trials. Time-frequency EEG analyses revealed bursts of delta (2-4 Hz) power associated with enhanced nP3 amplitudes to both task-switch cues and novel distracters-but no association with target P3b. These findings indicate that the P300-delta response indexes contextual novelty regardless of whether novelty emanates from endogenous (new task rules) or exogenous (novel distracters) sources of information. PMID:24673586

  6. Nucleus accumbens cocaine-amphetamine regulated transcript mediates food intake during novelty conflict.

    PubMed

    Burghardt, P R; Krolewski, D M; Dykhuis, K E; Ching, J; Pinawin, A M; Britton, S L; Koch, L G; Watson, S J; Akil, H

    2016-05-01

    Obesity is a persistent and pervasive problem, particularly in industrialized nations. It has come to be appreciated that the metabolic health of an individual can influence brain function and subsequent behavioral patterns. To examine the relationship between metabolic phenotype and central systems that regulate behavior, we tested rats with divergent metabolic phenotypes (Low Capacity Runner: LCR vs. High Capacity Runner: HCR) for behavioral responses to the conflict between hunger and environmental novelty using the novelty suppressed feeding (NSF) paradigm. Additionally, we measured expression of mRNA, for peptides involved in energy management, in response to fasting. Following a 24-h fast, LCR rats showed lower latencies to begin eating in a novel environment compared to HCR rats. A 48-h fast equilibrated the latency to begin eating in the novel environment. A 24-h fast differentially affected expression of cocaine-amphetamine regulated transcript (CART) mRNA in the nucleus accumbens (NAc), where 24-h of fasting reduced CART mRNA in LCR rats. Bilateral microinjections of CART 55-102 peptide into the NAc increased the latency to begin eating in the NSF paradigm following a 24-h fast in LCR rats. These results indicate that metabolic phenotype influences how animals cope with the conflict between hunger and novelty, and that these differences are at least partially mediated by CART signaling in the NAc. For individuals with poor metabolic health who have to navigate food-rich and stressful environments, changes in central systems that mediate conflicting drives may feed into the rates of obesity and exacerbate the difficulty individuals have in maintaining weight loss. PMID:26926827

  7. Something Old, Something New: A Developmental Transition from Familiarity to Novelty Preferences with Hidden Objects

    ERIC Educational Resources Information Center

    Shinskey, Jeanne L.; Munakata, Yuko

    2010-01-01

    Novelty seeking is viewed as adaptive, and novelty preferences in infancy predict cognitive performance into adulthood. Yet 7-month-olds prefer familiar stimuli to novel ones when searching for hidden objects, in contrast to their strong novelty preferences with visible objects (Shinskey & Munakata, 2005). According to a graded representations…

  8. Male accessory gland substances from Aedes albopictus affect the locomotor activity of Aedes aegypti females

    PubMed Central

    Lima-Camara, Tamara Nunes; Codeço, Claudia Torres; Honório, Nildimar Alves; Bruno, Rafaela Vieira; Peixoto, Alexandre Afranio; Lounibos, Leon Philip

    2013-01-01

    Dengue is one of the world’s most important mosquito-borne diseases and is usually transmitted by one of two vector species: Aedes aegypti or Aedes albopictus . These two diurnal mosquitoes are frequently found coexisting in similar habitats, enabling interactions between adults, such as cross-mating. The objective of this study was to assess cross-mating between Ae. aegypti females and Ae. albopictus males under artificial conditions and evaluate the locomotor activity of Ae. aegypti virgin females injected with male accessory gland (MAG) homogenates to infer the physiological and behavioural responses to interspecific mating. After seven days of exposure, 3.3-16% of Ae. aegypti females mated with Ae. albopictus males. Virgin Ae. aegypti females injected with conspecific and heterospecific MAGs showed a general decrease in locomotor activity compared to controls and were refractory to mating with conspecific males. The reduction in diurnal locomotor activity induced by injections of conspecific or heterospecific MAGs is consistent with regulation of female reproductive activities by male substances, which are capable of sterilising female Ae. aegypti through satyrisation by Ae. albopictus . PMID:24473799

  9. The effect of early environmental manipulation on locomotor sensitivity and methamphetamine conditioned place preference reward.

    PubMed

    Hensleigh, E; Pritchard, L M

    2014-07-15

    Early life stress leads to several effects on neurological development, affecting health and well-being later in life. Instances of child abuse and neglect are associated with higher rates of depression, risk taking behavior, and an increased risk of drug abuse later in life. This study used repeated neonatal separation of rat pups as a model of early life stress. Rat pups were either handled and weighed as controls or separated for 180 min per day during postnatal days 2-8. In adulthood, male and female rats were tested for methamphetamine conditioned place preference reward and methamphetamine induced locomotor activity. Tissue samples were collected and mRNA was quantified for the norepinephrine transporter in the prefrontal cortex and the dopamine transporter in the nucleus accumbens. Results indicated rats given methamphetamine formed a conditioned place preference, but there was no effect of early separation or sex. Separated males showed heightened methamphetamine-induced locomotor activity, but there was no effect of early separation for females. Overall females were more active than males in response to both saline and methamphetamine. No differences in mRNA levels were observed across any conditions. These results suggest early neonatal separation affects methamphetamine-induced locomotor activity in a sex-dependent manner but has no effects on methamphetamine conditioned place preference. PMID:24713150

  10. Alterations in locomotor activity induced by radioprotective doses of 16,16-dimethyl prostaglandin E2

    SciTech Connect

    Landauer, M.R.; Walden, T.L.; Davis, H.D.; Dominitz, J.A.

    1987-01-01

    16,16-Dimethyl prostaglandin E2 (DiPGE2) is an effective radioprotectant when administered before irradiation. A notable side effect of this compound is sedation. In separate experiments, the dose-response determinations of the time course of locomotor activity and 30-day survival after 10 Gy gamma irradiation (LD100) were made. Adult male CD2F1 mice were injected subcutaneously with vehicle or DiPGE2 in doses ranging from 0.01 to 40 micrograms per mouse. A dose of 0.01 micrograms did not result in alterations in locomotor behaviour or enhance survival. Doses greater than 1 microgram produced ataxia and enhanced radiation survival in a dose-dependent fashion. Full recovery of locomotor activity did not occur until 6 and 30 hr after injection for the 10 microgram and 40 microgram groups, respectively. Radioprotection was observed when DiPGE2 was administered preirradiation but not postirradiation. Doses of 1 and 10 micrograms were maximally effective as a radioprotectant if injected 5 min prior to irradiation (80%-90% survival). A dose of 40 micrograms resulted in 100% survival when injected 5-30 min before irradiation. Therefore, increasing doses of DiPGE2 resulted in an enhanced effectiveness as a radioprotectant. However, the doses that were the most radioprotective were also the most debilitating to the animal.

  11. The iFly Tracking System for an Automated Locomotor and Behavioural Analysis of Drosophila melanogaster

    PubMed Central

    Kohlhoff, Kai J.; Jahn, Thomas R.; Lomas, David A.; Dobson, Christopher M.; Crowther, Damian C.; Vendruscolo, Michele

    2016-01-01

    The use of animal models in medical research provides insights into molecular and cellular mechanisms of human disease, and helps identify and test novel therapeutic strategies. Drosophila melanogaster – the common fruit fly – is one of the most established model organisms, as its study can be performed more readily and with far less expense than for other model animal systems, such as mice, fish, or indeed primates. In the case of fruit flies, standard assays are based on the analysis of longevity and basic locomotor functions. Here we present the iFly tracking system, which enables to increase the amount of quantitative information that can be extracted from these studies, and to reduce significantly the duration and costs associated with them. The iFly system uses a single camera to simultaneously track the trajectories of up to 20 individual flies with about 100μm spatial and 33ms temporal resolution. The statistical analysis of fly movements recorded with such accuracy makes it possible to perform a rapid and fully automated quantitative analysis of locomotor changes in response to a range of different stimuli. We anticipate that the iFly method will reduce very considerably the costs and the duration of the testing of genetic and pharmacological interventions in Drosophila models, including an earlier detection of behavioural changes and a large increase in throughput compared to current longevity and locomotor assays. PMID:21698336

  12. THE EFFECT OF EARLY ENVIRONMENTAL MANIPULATION ON LOCOMOTOR SENSITIVITY AND METHAMPHETAMINE CONDITIONED PLACE PREFERENCE REWARD

    PubMed Central

    Hensleigh, E.; Pritchard, L. M.

    2014-01-01

    Early life stress leads to several effects on neurological development, affecting health and well-being later in life. Instances of child abuse and neglect are associated with higher rates of depression, risk taking behavior, and an increased risk of drug abuse later in life. This study used repeated neonatal separation of rat pups as a model of early life stress. Rat pups were either handled and weighed as controls or separated for 180 minutes per day during postnatal days 2-8. In adulthood, male and female rats were tested for methamphetamine conditioned place preference reward and methamphetamine induced locomotor activity. Tissue samples were collected and mRNA was quantified for the norepinephrine transporter in the prefrontal cortex and the dopamine transporter in the nucleus accumbens. Results indicated rats given methamphetamine formed a conditioned place preference, but there was no effect of early separation or sex. Separated males showed heightened methamphetamine-induced locomotor activity, but there was no effect of early separation for females. Overall females were more active than males in response to both saline and methamphetamine. No differences in mRNA levels were observed across any conditions. These results suggest early neonatal separation affects methamphetamine-induced locomotor activity in a sex-dependent manner but has no effects on methamphetamine conditioned place preference. PMID:24713150

  13. Muscle-specific modulation of vestibular reflexes with increased locomotor velocity and cadence.

    PubMed

    Dakin, Christopher J; Inglis, John Timothy; Chua, Romeo; Blouin, Jean-Sébastien

    2013-07-01

    Vestibular information is one of the many sensory signals used to stabilize the body during locomotion. When locomotor velocity increases, the influence of these signals appears to wane. It is unclear whether vestibular signals are globally attenuated with velocity or are influenced by factors such as whether a muscle is contributing to balance control. Here we investigate how vestibular sensory signals influence muscles of the leg during locomotion and what causes their attenuation with increasing locomotor velocity. We hypothesized that 1) vestibular signals influence the activity of all muscles engaged in the maintenance of medio-lateral stability during locomotion and 2) increases in both cadence and velocity would be associated with attenuation of these signals. We used a stochastic vestibular stimulus and recorded electromyographic signals from muscles of the ankle, knee, and hip. Participants walked using two cadences (52 and 78 steps/min) and two walking velocities (0.4 and 0.8 m/s). We observed phase-dependent modulation of vestibular influence over ongoing muscle activity in all recorded muscles. Within a stride, reversals of the muscle responses were observed in the biceps femoris, tibialis anterior, and rectus femoris. Vestibular-muscle coupling decreases with increases in both cadence and walking velocity. These results show that the observed vestibular suppression is muscle- and phase dependent. We suggest that the phase- and muscle-specific influence of vestibular signals on locomotor activity is organized according to each muscle's functional role in body stabilization during locomotion. PMID:23576695

  14. Home tank water versus novel water differentially affect alcohol-induced locomotor activity and anxiety related behaviours in zebrafish.

    PubMed

    Tran, Steven; Facciol, Amanda; Gerlai, Robert

    2016-05-01

    The zebrafish may be uniquely well suited for studying alcohol's mechanisms of action in vivo, since alcohol can be administered via immersion in a non-invasive manner. Despite the robust behavioural effects of alcohol administration in mammals, studies reporting the locomotor stimulant and anxiolytic effects of alcohol in zebrafish have been inconsistent. In the current study, we examined whether differences in the type of water used for alcohol exposure and behavioural testing contribute to these inconsistencies. To answer this question, we exposed zebrafish to either home water from their housing tanks or novel water from an isolated reservoir (i.e. water lacking zebrafish chemosensory and olfactory cues) with 0% or 1% v/v alcohol for 30min, a 2×2 between subject experimental designs. Behavioural responses were quantified throughout the 30-minute exposure session via a video tracking system. Although control zebrafish exposed to home water and novel water were virtually indistinguishable in their behavioural responses, alcohol's effect on locomotor activity and anxiety-like behavioural responses were dependent on the type of water used for testing. Alcohol exposure in home tank water produced a mild anxiolytic and locomotor stimulant effect, whereas alcohol exposure in novel water produced an anxiogenic effect without altering locomotor activity. These results represent a dissociation between alcohol's effects on locomotor and anxiety related responses, and also illustrate how environmental factors, in this case familiarity with the water, may interact with such effects. In light of these findings, we urge researchers to explicitly state the type of water used. PMID:26921455

  15. Reduced locomotor activity and exploratory behavior in CC chemokine receptor 4 deficient mice.

    PubMed

    Ambrée, Oliver; Klassen, Irene; Förster, Irmgard; Arolt, Volker; Scheu, Stefanie; Alferink, Judith

    2016-11-01

    Chemokines and their receptors are key regulators of immune cell trafficking and activation. Recent findings suggest that they may also play pathophysiological roles in psychiatric diseases like depression and anxiety disorders. The CC chemokine receptor 4 (CCR4) and its two ligands, CCL17 and CCL22, are functionally involved in neuroinflammation as well as anti-infectious and autoimmune responses. However, their influence on behavior remains unknown. Here we characterized the functional role of the CCR4-CCL17 chemokine-receptor axis in the modulation of anxiety-related behavior, locomotor activity, and object exploration and recognition. Additionally, we investigated social exploration of CCR4 and CCL17 knockout mice and wild type (WT) controls. CCR4 knockout (CCR4(-/-)) mice exhibited fewer anxiety-related behaviors in the elevated plus-maze, diminished locomotor activity, exploratory behavior, and social exploration, while their recognition memory was not affected. In contrast, CCL17 deficient mice did not show an altered behavior compared to WT mice regarding locomotor activity, anxiety-related behavior, social exploration, and object recognition memory. In the dark-light and object recognition tests, CCL17(-/-) mice even covered longer distances than WT mice. These data demonstrate a mechanistic or developmental role of CCR4 in the regulation of locomotor and exploratory behaviors, whereas the ligand CCL17 appears not to be involved in the behaviors measured here. Thus, either CCL17 and the alternative ligand CCL22 may be redundant, or CCL22 is the main activator of CCR4 in these processes. Taken together, these findings contribute to the growing evidence regarding the involvement of chemokines and their receptors in the regulation of behavior. PMID:27469058

  16. Alpha-asarone improves striatal cholinergic function and locomotor hyperactivity in Fmr1 knockout mice.

    PubMed

    Qiu, Guozhen; Chen, Shengqiang; Guo, Jialing; Wu, Jie; Yi, Yong-Hong

    2016-10-01

    Hyperactivity is a symptom found in several neurological and psychiatric disorders, including Fragile X syndrome (FXS). The animal model of FXS, fragile X mental retardation gene (Fmr1) knockout (KO) mouse, exhibits robust locomotor hyperactivity. Alpha (α)-asarone, a major bioactive component isolated from Acorus gramineus, has been shown in previous studies to improve various disease conditions including central nervous system disorders. In this study, we show that treatment with α-asarone alleviates locomotor hyperactivity in Fmr1 KO mice. To elucidate the mechanism underlying this improvement, we evaluated the expressions of various cholinergic markers, as well as acetylcholinesterase (AChE) activity and acetylcholine (ACh) levels, in the striatum of Fmr1 KO mice. We also analyzed the AChE-inhibitory activity of α-asarone. Striatal samples from Fmr1 KO mice showed decreased m1 muscarinic acetylcholine receptor (m1 mAChR) expression, increased AChE activity, and reduced ACh levels. Treatment with α-asarone improved m1 mAChR expression and ACh levels, and attenuated the increased AChE activity. In addition, α-asarone dose-dependently inhibited AChE activity in vitro. These results indicate that direct inhibition of AChE activity and up-regulation of m1 mAChR expression in the striatum might contribute to the beneficial effects of α-asarone on locomotor hyperactivity in Fmr1 KO mice. These findings might improve understanding of the neurobiological mechanisms responsible for locomotor hyperactivity. PMID:27316341

  17. Semi-Supervised Eigenbasis Novelty Detection

    NASA Technical Reports Server (NTRS)

    Wagstaff, Kiri L.; Thompson, David R.

    2013-01-01

    Recent discoveries in high-time-resolution radio astronomy data have focused attention on a new class of events. Fast transients are rare pulses of radio frequency energy lasting from microseconds to seconds that might be produced by a variety of exotic astrophysical phenomena. For example, X-ray bursts, neutron stars, and active galactic nuclei are all possible sources of short-duration, transient radio signals. It is difficult to anticipate where such signals might appear, and they are most commonly discovered through analysis of high-time- resolution data that had been collected for other purposes. Transients are often faint and difficult to detect, so improved detection algorithms can directly benefit the science yield of all such commensal monitoring. A new detection algorithm learns a low-dimensional linear manifold for describing the normal data. High reconstruction error indicates a novel signal that does not match the patterns of normal data. One unsupervised portion of the manifold model adapts its representation in response to recent data. A second supervised portion of the model is made of a basis trained in advance using labeled examples of RFI; this prevents false positives due to these events. For a linear model, an orthonormalization operation is used to combine these bases prior to the anomaly detection decision. Another novel aspect of the approach lies in combining basis vectors learned in an unsupervised, online fashion from the data stream with supervised basis vectors learned in advance from known examples of false alarms. Adaptive, data-driven detection is achieved that is also informed by existing domain knowledge about signals that may be statistically anomalous, but are not interesting and should therefore be ignored. The method was evaluated using data from the Parkes Multibeam Survey. This data set was originally collected to search for pulsars, which are astronomical sources that emit radio pulses at regular periods. However, several

  18. NOVELTY DETECTION USING AUTO-ASSOCIATIVE NEURAL NETWORK

    SciTech Connect

    H. SOHN; K. WORDEN; C. FARRAR

    2001-05-01

    The primary objective of novelty detection is to examine if a system significantly deviates from the initial baseline condition of the system. In reality, the system is often subject to changing environmental and operation conditions affecting its dynamic characteristics. Such variations include changes in loading, boundary conditions, temperature, and humidity. Most damage diagnosis techniques, however, generally neglect the effects of these changing ambient conditions. Here, a novelty detection technique is developed explicitly taking into account these natural variations of the system in order to minimize false positive indications of true system changes. Auto-associative neural networks are employed to discriminate system changes of interest such as structural deterioration and damage from the natural variations of the system.

  19. What’s New? Children Prefer Novelty in Referent Selection

    PubMed Central

    Horst, Jessica S.; Samuelson, Larissa K.; Kucker, Sarah C.; McMurray, Bob

    2010-01-01

    Determining the referent of a novel name is a critical task for young language learners. The majority of studies on children’s referent selection focus on manipulating the sources of information (linguistic, contextual and pragmatic) that children can use to solve the referent mapping problem. Here, we take a step back and explore how children’s endogenous biases towards novelty and their own familiarity with novel objects influence their performance in such a task. We familiarized 2-year-old children with previously novel objects. Then, on novel name referent selection trials children were asked to select the referent from three novel objects: two previously seen and one completely novel object. Children demonstrated a clear bias to select the most novel object. A second experiment controls for pragmatic responding and replicates this finding. We conclude, therefore, that children’s referent selection is biased by previous exposure and children’s endogenous bias to novelty. PMID:21092945

  20. Surprise? Early visual novelty processing is not modulated by attention

    PubMed Central

    Tarbi, Elise C.; Sun, Xue; Holcomb, Phillip J.; Daffner, Kirk R.

    2010-01-01

    This study investigated the influence of direction of attention on the early detection of visual novelty, as indexed by the anterior N2. The anterior N2 was measured in young subjects (n=32) under an Attend and Ignore condition. Subjects were presented standard, target/rare, and perceptually novel visual stimuli under both conditions, but under the Ignore condition, attention was directed towards an auditory n-back task. The size of the anterior N2 to novel stimuli did not differ between conditions and was significantly larger than the anterior N2 to all other stimulus types. Furthermore, under the Ignore condition, the anterior N2 to visual novel stimuli was not affected by the level of difficulty of the auditory n-back task (3-back vs. 2-back). Our findings suggest that the early processing of visual novelty, as measured by the size of the anterior N2, is not strongly modulated by direction of attention. PMID:20880260

  1. Detecting Falls as Novelties in Acceleration Patterns Acquired with Smartphones

    PubMed Central

    Medrano, Carlos; Igual, Raul; Plaza, Inmaculada; Castro, Manuel

    2014-01-01

    Despite being a major public health problem, falls in the elderly cannot be detected efficiently yet. Many studies have used acceleration as the main input to discriminate between falls and activities of daily living (ADL). In recent years, there has been an increasing interest in using smartphones for fall detection. The most promising results have been obtained by supervised Machine Learning algorithms. However, a drawback of these approaches is that they rely on falls simulated by young or mature people, which might not represent every possible fall situation and might be different from older people's falls. Thus, we propose to tackle the problem of fall detection by applying a kind of novelty detection methods which rely only on true ADL. In this way, a fall is any abnormal movement with respect to ADL. A system based on these methods could easily adapt itself to new situations since new ADL could be recorded continuously and the system could be re-trained on the fly. The goal of this work is to explore the use of such novelty detectors by selecting one of them and by comparing it with a state-of-the-art traditional supervised method under different conditions. The data sets we have collected were recorded with smartphones. Ten volunteers simulated eight type of falls, whereas ADL were recorded while they carried the phone in their real life. Even though we have not collected data from the elderly, the data sets were suitable to check the adaptability of novelty detectors. They have been made publicly available to improve the reproducibility of our results. We have studied several novelty detection methods, selecting the nearest neighbour-based technique (NN) as the most suitable. Then, we have compared NN with the Support Vector Machine (SVM). In most situations a generic SVM outperformed an adapted NN. PMID:24736626

  2. Automatic assessment of scintmammographic images using a novelty filter.

    PubMed Central

    Costa, M.; Moura, L.

    1995-01-01

    99mTc-sestamibi scintmammograms provide a powerful non-invasive means for detecting breast cancer at early stages. This paper describes an automatic method for detecting breast tumors in such mammograms. The proposed method not only detects tumors but also classifies non-tumor images as "normal" or "diffuse increased uptake" mammograms. The detection method makes use of Kohonen's "novelty filter". In this technique an orthogonal vector basis is created from a normal set of images. Test images presented to the detection method are described as a linear combination of the images in the vector basis. Assuming that the image basis is representative of normal patterns, then it can be expected that there should be no major differences between a normal test image and its corresponding linear combination image. However, if the test image presents an abnormal pattern, then it is expected that the "abnormalities" will show as the difference between the original test image and the image built from the vector basis. In other words, the existing abnormality cannot be explained by the set of normal images and comes up as a "novelty." An important part of the proposed method are the steps taken for standardizing images before they can be used as part of the vector basis. Standardization is the keystone to the success of the proposed method, as the novelty filter is very sensitive to changes in shape and alignment. Images Figure 1 Figure 2 PMID:8563342

  3. Corticotropin-releasing factor receptor 1 activation during exposure to novelty stress protects against Alzheimer's disease-like cognitive decline in AβPP/PS1 mice.

    PubMed

    Scullion, Gillian A; Hewitt, Katherine N; Pardon, Marie-Christine

    2013-01-01

    A lifestyle rich in physical and mental activities protects against Alzheimer's disease (AD) but the underlying mechanisms are unclear. We have proposed that this is mediated by a stress response and have shown that repeated exposure to novelty stress, which induces physical and exploratory activities, delays the progression of AD-like pathology in the TASTPM mouse model. Here, we aimed to establish the role played by corticotrophin-releasing factor receptor 1 (CRFR1), a major component of the stress axis, in TASTPM's behavioral and neuroendocrine responses to novelty and related protective effects. We show that the stress response of TASTPM mice is altered with reduced CRFR1-mediated neuroendocrine and behavioral responses to novelty and a distinct profile of behavioral responses. Repeated novelty-induced CRFR1 activation, however, mediated the improved contextual fear memory and extinction performance of TASTPM mice and increased hippocampal and fronto-cortical levels of synaptophysin, a marker of synaptic density, and fronto-cortical levels of the post-synaptic marker PSD95. The N-methyl-D-aspartate receptor (NMDAR) is the major receptor for synaptic plasticity underlying learning and memory. Although novelty-induced NMDAR activation contributed to enhancement of fear memory and synaptophysin levels, antagonism of CRFR1 and NMDAR prevented the novelty-induced increase in hippocampal synaptophysin levels but reversed the other effects of CRFR1 inactivation, i.e., the enhancement of contextual fear extinction and fronto-cortical synaptophysin and PSD95 levels. These findings suggest a novel mechanism whereby a stimulating environment can delay AD symptoms through CRFR1 activation, facilitating NMDAR-mediated synaptic plasticity and synaptogenesis in a region-dependent manner, either directly, or indirectly, by modulating PSD95. PMID:23302658

  4. The importance of novelty: male-female interactions among blue-black grassquits in captivity.

    PubMed

    Dias, Raphael I; Oliveira, Rui F; Podos, Jeffrey; Macedo, Regina H

    2014-03-01

    Mate choice is a primary mechanism driving the evolution of sexually selected traits such as elaborate displays and ornaments. In a majority of taxa studied to date, females are seen to actively sample and evaluate multiple males, presumably to optimize mating opportunities. During this process females may encounter males both familiar and novel, a distinction that might influence how mate choice proceeds. Using a socially monogamous passerine, the blue-black grassquit (Volatinia jacarina), we studied how females respond to novel versus familiar ("paired") males, and how encounters with novel males influence subsequent interactions with their paired males. Additionally, we measured the hormonal response of males after visualizing their paired females interacting with novel males. We found that females were attentive to novel males irrespective of these males' phenotypic attributes, suggesting that in these interactions novelty is highly relevant. After exposure to novel males, females tended to respond aggressively towards their paired males; by contrast, the behaviour of males towards their paired females did not change. Moreover, we did not detect any hormonal responses of males to viewing their paired females interacting with novel males. Together these results suggest that the distinction between familiarity and novelty may hold special relevance for females in mate choice, a finding that bears upon our understanding of the evolution of extra-pair paternity and reproductive behaviour. PMID:24406508

  5. MMN and novelty P3 in coma and other altered states of consciousness: a review.

    PubMed

    Morlet, Dominique; Fischer, Catherine

    2014-07-01

    In recent decades, there has been a growing interest in the assessment of patients in altered states of consciousness. There is a need for accurate and early prediction of awakening and recovery from coma. Neurophysiological assessment of coma was once restricted to brainstem auditory and primary cortex somatosensory evoked potentials elicited in the 30 ms range, which have both shown good predictive value for poor coma outcome only. In this paper, we review how passive auditory oddball paradigms including deviant and novel sounds have proved their efficiency in assessing brain function at a higher level, without requiring the patient's active involvement, thus providing an enhanced tool for the prediction of coma outcome. The presence of an MMN in response to deviant stimuli highlights preserved automatic sensory memory processes. Recorded during coma, MMN has shown high specificity as a predictor of recovery of consciousness. The presence of a novelty P3 in response to the subject's own first name presented as a novel (rare) stimulus has shown a good correlation with coma awakening. There is now a growing interest in the search for markers of consciousness, if there are any, in unresponsive patients (chronic vegetative or minimally conscious states). We discuss the different ERP patterns observed in these patients. The presence of novelty P3, including parietal components and possibly followed by a late parietal positivity, raises the possibility that some awareness processes are at work in these unresponsive patients. PMID:24281786

  6. An Investigation of the Effects of Maternal Separation and Novelty on Central Mechanisms Mediating Pituitary-Adrenal Activity in Infant Guinea Pigs (Cavia porcellus)

    PubMed Central

    Maken, Deborah S.; Weinberg, Joanne; Cool, David R.; Hennessy, Michael B.

    2016-01-01

    In mammalian species in which the young exhibit a strong filial attachment (e.g., monkeys, guinea pigs), numerous studies have shown that even brief separation from the attachment figure potently elevates circulating concentrations of glucocorticoids and adrenocorticotropic hormone (ACTH). However, effects of separation on central regulation of this stress response are not known. Therefore, we investigated central mechanisms mediating pituitary-adrenal activation during maternal separation and novelty exposure in guinea pig (Cavia porcellus) pups. Corticotropin-releasing factor (CRF) mRNA expression in the hypothalamic paraventricular nucleus (PVN), and plasma cortisol and ACTH levels, were elevated only during separation in a novel environment. C-Fos activity was elevated in the medial amygdala (MeA) and reduced in the bed nucleus of the stria terminalis (BNST) during novelty exposure, regardless of separation. On the other hand, c-Fos activity was elevated in the PVN during separation, regardless of novelty exposure. These results demonstrate independent and combined effects of separation and novelty in regions of the guinea pig CNS that regulate pituitary-adrenal activity. Moreover, they suggest that a pathway from MeA to BNST to PVN mediates responses to novelty in the guinea pig pup, as in the adult rat, though inputs from other cell populations appear required to fully account for the HPA activity observed here. PMID:21038937

  7. The mesencephalic locomotor region sends a bilateral glutamatergic drive to hindbrain reticulospinal neurons in a tetrapod.

    PubMed

    Ryczko, Dimitri; Auclair, Francois; Cabelguen, Jean-Marie; Dubuc, Réjean

    2016-05-01

    In vertebrates, stimulation of the mesencephalic locomotor region (MLR) on one side evokes symmetrical locomotor movements on both sides. How this occurs was previously examined in detail in a swimmer using body undulations (lamprey), but in tetrapods the downstream projections from the MLR to brainstem neurons are not fully understood. Here we examined the brainstem circuits from the MLR to identified reticulospinal neurons in the salamander Notophthalmus viridescens. Using neural tracing, we show that the MLR sends bilateral projections to the middle reticular nucleus (mRN, rostral hindbrain) and the inferior reticular nucleus (iRN, caudal hindbrain). Ca(2+) imaging coupled to electrophysiology in in vitro isolated brains revealed very similar responses in reticulospinal neurons on both sides to a unilateral MLR stimulation. As the strength of MLR stimulation was increased, the responses increased in size in reticulospinal neurons of the mRN and iRN, but the responses in the iRN were smaller. Bath-application or local microinjections of glutamatergic antagonists markedly reduced reticulospinal neuron responses, indicating that the MLR sends glutamatergic inputs to reticulospinal neurons. In addition, reticulospinal cells responded to glutamate microinjections and the size of the responses paralleled the amount of glutamate microinjected. Immunofluorescence coupled with anatomical tracing confirmed the presence of glutamatergic projections from the MLR to reticulospinal neurons. Overall, we show that the brainstem circuits activated by the MLR in the salamander are organized similarly to those previously described in lampreys, indicating that the anatomo-physiological features of the locomotor drive are well conserved in vertebrates. J. Comp. Neurol. 524:1361-1383, 2016. © 2015 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc. PMID:26470600

  8. Flexibility in locomotor-feeding integration during prey capture in varanid lizards: effects of prey size and velocity.

    PubMed

    Montuelle, Stéphane J; Herrel, Anthony; Libourel, Paul-Antoine; Daillie, Sandra; Bels, Vincent L

    2012-11-01

    Feeding movements are adjusted in response to food properties, and this flexibility is essential for omnivorous predators as food properties vary routinely. In most lizards, prey capture is no longer considered to solely rely on the movements of the feeding structures (jaws, hyolingual apparatus) but instead is understood to require the integration of the feeding system with the locomotor system (i.e. coordination of movements). Here, we investigated flexibility in the coordination pattern between jaw, neck and forelimb movements in omnivorous varanid lizards feeding on four prey types varying in length and mobility: grasshoppers, live newborn mice, adult mice and dead adult mice. We tested for bivariate correlations between 3D locomotor and feeding kinematics, and compared the jaw-neck-forelimb coordination patterns across prey types. Our results reveal that locomotor-feeding integration is essential for the capture of evasive prey, and that different jaw-neck-forelimb coordination patterns are used to capture different prey types. Jaw-neck-forelimb coordination is indeed significantly altered by the length and speed of the prey, indicating that a similar coordination pattern can be finely tuned in response to prey stimuli. These results suggest feed-forward as well as feed-back modulation of the control of locomotor-feeding integration. As varanids are considered to be specialized in the capture of evasive prey (although they retain their ability to feed on a wide variety of prey items), flexibility in locomotor-feeding integration in response to prey mobility is proposed to be a key component in their dietary specialization. PMID:22899521

  9. Enhancing offspring hypothalamic-pituitary-adrenal (HPA) regulation via systematic novelty exposure: the influence of maternal HPA function

    PubMed Central

    Dinces, Sarah M.; Romeo, Russell D.; McEwen, Bruce S.; Tang, Akaysha C.

    2014-01-01

    In the rat, repeated brief exposures to novelty early in life can induce long-lasting enhancements in adult cognitive, social, emotional, and neuroendocrine function. Family-to-family variations in these intervention effects on adult offspring are predicted by the mother’s ability to mount a rapid corticosterone (CORT) response to the onset of an acute stressor. Here, in Long-Evans rats, we investigated whether neonatal and adulthood novelty exposure, each individually and in combination, can enhance offspring hypothalamic-pituitary-adrenal (HPA) regulation. Using a 2 × 2 within-litter design, one half of each litter were exposed to a relatively novel non-home environment for 3-min (Neo_Novel) daily during infancy (PND 1–21) and the other half of the litter remained in the home cage (Neo_Home); we further exposed half of these two groups to early adulthood (PND 54–63) novelty exposure in an open field and the remaining siblings stayed in their home cages. Two aspects of HPA regulation were assessed: the ability to maintain a low level of resting CORT (CORTB) and the ability to mount a large rapid CORT response (CORTE) to the onset of an acute stressor. Assessment of adult offspring’s ability to regulate HPA regulation began at 370 days of age. We further investigated whether the novelty exposure effects on offspring HPA regulation are sensitive to the context of maternal HPA regulation by assessing maternal HPA regulation similarly beginning 7 days after her pups were weaned. We found that at the population level, rats receiving neonatal, but not early adulthood exposure or both, showed a greater rapid CORTE than their home-staying siblings. At the individual family level, these novelty effects are positively associated with maternal CORTE. These results suggest that early experience of novelty can enhance the offspring’s ability to mount a rapid response to environmental challenge and the success of such early life intervention is critically dependent

  10. Modular diversification of the locomotor system in damselfishes (Pomacentridae).

    PubMed

    Aguilar-Medrano, Rosalía; Frédérich, Bruno; Barber, Paul H

    2016-05-01

    As fish move and interact with their aquatic environment by swimming, small morphological variations of the locomotor system can have profound implications on fitness. Damselfishes (Pomacentridae) have inhabited coral reef ecosystems for more than 50 million years. As such, habitat preferences and behavior could significantly constrain the morphology and evolvability of the locomotor system. To test this hypothesis, we used phylogenetic comparative methods on morphometric, ecological and behavioral data. While body elongation represented the primary source of variation in the locomotor system of damselfishes, results also showed a diverse suite of morphological combinations between extreme morphologies. Results show clear associations between behavior, habitat preferences, and morphology, suggesting ecological constraints on shape diversification of the locomotor system. In addition, results indicate that the three modules of the locomotor system are weakly correlated, resulting in versatile and independent characters. These results suggest that Pomacentridae is shape may result from the interaction between (1) integrated parts of morphological variation that maintain overall swimming ability and (2) relatively independent parts of the morphology that facilitate adaptation and diversification. J. Morphol. 277:603-614, 2016. © 2016 Wiley Periodicals, Inc. PMID:26919129

  11. The ventromedial hypothalamus oxytocin induces locomotor behavior regulated by estrogen.

    PubMed

    Narita, Kazumi; Murata, Takuya; Matsuoka, Satoshi

    2016-10-01

    Our previous studies demonstrated that excitation of neurons in the rat ventromedial hypothalamus (VMH) induced locomotor activity. An oxytocin receptor (Oxtr) exists in the VMH and plays a role in regulating sexual behavior. However, the role of Oxtr in the VMH in locomotor activity is not clear. In this study we examined the roles of oxytocin in the VMH in running behavior, and also investigated the involvement of estrogen in this behavioral change. Microinjection of oxytocin into the VMH induced a dose-dependent increase in the running behavior in male rats. The oxytocin-induced running activity was inhibited by simultaneous injection of Oxtr-antagonist, (d(CH2)5(1), Try(Me)(2), Orn(8))-oxytocin. Oxytocin injection also induced running behavior in ovariectomized (OVX) female rats. Pretreatment of the OVX rats with estrogen augmented the oxytocin-induced running activity twofold, and increased the Oxtr mRNA in the VMH threefold. During the estrus cycle locomotor activity spontaneously increased in the dark period of proestrus. The Oxtr mRNA was up-regulated in the proestrus afternoon. Blockade of oxytocin neurotransmission by its antagonist before the onset of the dark period of proestrus decreased the following nocturnal locomotor activity. These findings demonstrate that Oxtr in the VMH is involved in the induction of running behavior and that estrogen facilitates this effect by means of Oxtr up-regulation, suggesting the involvement of oxytocin in the locomotor activity of proestrus female rats. PMID:27237044

  12. Rotation, locomotor activity and individual differences in voluntary ethanol consumption.

    PubMed

    Nielsen, D M; Crosley, K J; Keller, R W; Glick, S D; Carlson, J N

    1999-03-27

    Spontaneous turning behavior and locomotor activity were evaluated for their ability to predict differences in the voluntary consumption of ethanol in male Long-Evans rats. Animals were assessed for their preferred direction of turning behavior and for high vs. low levels of spontaneous locomotor activity, as determined during nocturnal testing in a rotometer. Subsequently, preference for a 10% ethanol solution vs. water was determined in a 24-h two-bottle home-cage free-choice paradigm. Rats exhibiting a right-turning preference consumed more ethanol than rats showing a left-turning preference. While locomotor activity alone did not predict differences in drinking, turning and locomotor activity together predicted differences in ethanol consumption. Low-activity right-turning rats consumed more ethanol than all the other groups of rats. Previous studies from this laboratory have shown that individual differences in turning behavior are accompanied by different asymmetries in dopamine (DA) function in the medial prefrontal cortex (mPFC). Individual differences in locomotor activity are associated with differences in nucleus accumbens (NAS) DA function. The present data suggest that variations in mPFC DA asymmetry and NAS DA function may underlie differences in the voluntary consumption of ethanol. PMID:10095014

  13. Prefrontal microRNA-221 Mediates Environmental Enrichment-Induced Increase of Locomotor Sensitivity to Nicotine

    PubMed Central

    Gomez, Adrian M.; Altomare, Diego; Sun, Wei-Lun; Midde, Narasimha M.; Ji, Hao; Shtutman, Michael; Turner, Jill R.; Creek, Kim E.

    2016-01-01

    Background: Environmental enrichment alters susceptibility in developing drug addiction. We have demonstrated that rats raised in an enriched condition are more sensitive than rats raised in an impoverished condition to nicotine-induced locomotor activity, and this is associated with alterations of phosphorylated extracellular signal-regulated kinase 1/2 within the prefrontal cortex. This study determined the impact of microRNA-221 in the prefrontal cortex on phosphorylated extracellular signal-regulated kinase 1/2 and the enriched environment-dependent behavioral changes in response to nicotine. Methods: A microRNA array was conducted to profile microRNA expression in the prefrontal cortex of enriched condition and impoverished condition rats in response to repeated nicotine (0.35mg/kg, s.c.) administration. microRNA-221 in the prefrontal cortex, nucleus accumbens, and striatum was further verified by quantitative real-time PCR. Lentiviral-mediated overexpression of microRNA-221 in PC12 cells and the medial prefrontal cortex was performed to determine the effects of microRNA-221 on nicotine-mediated phosphorylated extracellular signal-regulated kinase 1/2, phosphorylated cAMP-response element-binding protein, and locomotor activity. Results: microRNA-221 was profoundly upregulated in the prefrontal cortex but not in nucleus accumbens and striatum of enriched condition rats relative to impoverished condition rats following repeated administration of nicotine. Overexpression of lentiviral-microRNA-221 attenuated nicotine-induced increase in phosphorylated extracellular signal-regulated kinase 1/2 in PC12 cells. Lentiviral-microRNA-221 overexpression in the medial prefrontal cortex further increased locomotor activity in impoverished condition but not in enriched condition rats in response to repeated nicotine administration. Accordingly, lentiviral-microRNA-221 attenuated nicotine-induced increases in phosphorylated extracellular signal-regulated kinase 1/2 and

  14. Individual Differences in Novelty-Seeking Behavior in Rats as a Model for Psychosocial Stress-Related Mood Disorders

    PubMed Central

    Duclot, Florian; Hollis, Fiona; Darcy, Michael J.; Kabbaj, Mohamed

    2011-01-01

    Most of the neuropsychiatric disorders, including stress-related mood disorders, are complex multi-parametric syndromes. Diagnoses are therefore hard to establish and current therapeutic strategies suffer from important variability in effectiveness, making the understanding of inter-individual variations crucial to unveiling effective new treatments. In rats, such individual differences are observed during exposure to a novel environment, where individuals will present with either high or low locomotor activity and can thus be separated into high (HR) and low (LR) responders, respectively. In rodents, a long-lasting psychosocial stress-induced depressive state can be triggered by exposure to a social defeat procedure. We therefore analyzed the respective vulnerabilities of HR and LR animals to long-lasting, social defeat-induced behavioral alterations relevant to mood disorders. Two weeks after four daily consecutive social defeat exposures, HR animals exhibit higher anxiety levels, reduced body weight gain and sucrose preference, as well as a marked social avoidance. LR animals, however, remain unaffected. Moreover, while repeated social defeat exposure induces long-lasting contextual fear memory in both HR and LR animals, only HR individuals exhibit marked freezing behavior four weeks after a single social defeat. Combined, these findings highlight the critical involvement of inter-individual variations in novelty-seeking behavior in the vulnerability to stress-related mood disorders, and uncover a promising model for posttraumatic stress disorder. PMID:21172365

  15. Down-Regulation of Decapping Protein 2 Mediates Chronic Nicotine Exposure-Induced Locomotor Hyperactivity in Drosophila

    PubMed Central

    Ren, Jing; Sun, Jinghan; Zhang, Yunpeng; Liu, Tong; Ren, Qingzhong; Li, Yan; Guo, Aike

    2012-01-01

    Long-term tobacco use causes nicotine dependence via the regulation of a wide range of genes and is accompanied by various health problems. Studies in mammalian systems have revealed some key factors involved in the effects of nicotine, including nicotinic acetylcholine receptors (nAChRs), dopamine and other neurotransmitters. Nevertheless, the signaling pathways that link nicotine-induced molecular and behavioral modifications remain elusive. Utilizing a chronic nicotine administration paradigm, we found that adult male fruit flies exhibited locomotor hyperactivity after three consecutive days of nicotine exposure, while nicotine-naive flies did not. Strikingly, this chronic nicotine-induced locomotor hyperactivity (cNILH) was abolished in Decapping Protein 2 or 1 (Dcp2 or Dcp1) -deficient flies, while only Dcp2-deficient flies exhibited higher basal levels of locomotor activity than controls. These results indicate that Dcp2 plays a critical role in the response to chronic nicotine exposure. Moreover, the messenger RNA (mRNA) level of Dcp2 in the fly head was suppressed by chronic nicotine treatment, and up-regulation of Dcp2 expression in the nervous system blocked cNILH. These results indicate that down-regulation of Dcp2 mediates chronic nicotine-exposure-induced locomotor hyperactivity in Drosophila. The decapping proteins play a major role in mRNA degradation; however, their function in the nervous system has rarely been investigated. Our findings reveal a significant role for the mRNA decapping pathway in developing locomotor hyperactivity in response to chronic nicotine exposure and identify Dcp2 as a potential candidate for future research on nicotine dependence. PMID:23300696

  16. Developing Sensorimotor Countermeasures to Mitigate Post-Flight Locomotor Dysfunction

    NASA Technical Reports Server (NTRS)

    Bloomberg, J. J.; Mulavara, A. P.; Cohen, H.; Miller, C. A.; Richards, J. T.; Houser, J.; McDonald, P. V.; Seidler, R. D.; Merkle, L. A.; Stelmach, G. E.

    2001-01-01

    Following spaceflight, crewmembers experience postural and locomotor instability. The magnitude and duration of post-flight sensorimotor disturbances increase with longer duration exposure to microgravity. These post-flight postural and locomotor alterations can pose a risk to crew safety and to mission objectives if nominal or emergency vehicle egress is required immediately following long-duration spaceflight. Gait instabilities could prevent or extend the time required to make an emergency egress from the Orbiter, Crew Return Vehicle or a future Martian lander leading to compromised mission objectives. We propose a countermeasure that aids in maintaining functional locomotor performance. This includes retaining the ability to perform vehicular egress and meet early mission objectives soon after landing on a planetary surface.

  17. Association of locomotor complaints and disability in the Rotterdam study.

    PubMed Central

    Odding, E; Valkenburg, H A; Algra, D; Vandenouweland, F A; Grobbee, D E; Hofman, A

    1995-01-01

    OBJECTIVE--To determine the association between joint complaints and locomotor disability. METHODS--During a home interview survey 1901 men and 3135 women aged 55 years and over (the Rotterdam Study) were asked about joint pain and morning stiffness in the past month, and locomotor disability was assessed by six questions from the Health Assessment Questionnaire (HAQ). RESULTS--The prevalence of locomotor disability was 24.5% for men and 40.5% for women. The prevalence of joint pain in men was 0.7% for pain in the hips, knees, and feet simultaneously, 3.7% for pain at two joint sites, 16.0% for pain at one joint site, and 20.4% for pain in the hips and/or knees and/or feet (any joint site); the corresponding estimates for women were 1.9%, 9.0%, 23.7%, and 34.5%, respectively. The prevalence of generalised morning stiffness was 4.9% for men and 10.4% for women. The age adjusted odds ratios for locomotor disability in men ranged from 2.4 of pain at one joint site to 8.8 of pain at all three joint sites; for women these odds ratios varied between 2.5 and 5.7, respectively. The age adjusted odds ratios of generalised morning stiffness were 8.0 for men and 7.3 for women. CONCLUSION--There is a strong and independent association between locomotor disability and age, joint pain, and generalised morning stiffness in people aged 55 years and over. The odds for locomotor disability increase onefold for every year increase in age, while the presence of generalised morning stiffness is of greater influence than the presence of joint pain. PMID:7495342

  18. Dimensions of integration in interdisciplinary explanations of the origin of evolutionary novelty.

    PubMed

    Love, Alan C; Lugar, Gary L

    2013-12-01

    Many philosophers of biology have embraced a version of pluralism in response to the failure of theory reduction but overlook how concepts, methods, and explanatory resources are in fact coordinated, such as in interdisciplinary research where the aim is to integrate different strands into an articulated whole. This is observable for the origin of evolutionary novelty-a complex problem that requires a synthesis of intellectual resources from different fields to arrive at robust answers to multiple allied questions. It is an apt locus for exploring new dimensions of explanatory integration because it necessitates coordination among historical and experimental disciplines (e.g., geology and molecular biology). These coordination issues are widespread for the origin of novel morphologies observed in the Cambrian Explosion. Despite an explicit commitment to an integrated, interdisciplinary explanation, some potential disciplinary contributors are excluded. Notable among these exclusions is the physics of ontogeny. We argue that two different dimensions of integration-data and standards-have been insufficiently distinguished. This distinction accounts for why physics-based explanatory contributions to the origin of novelty have been resisted: they do not integrate certain types of data and differ in how they conceptualize the standard of uniformitarianism in historical, causal explanations. Our analysis of these different dimensions of integration contributes to the development of more adequate and integrated explanatory frameworks. PMID:24161490

  19. Genotypic structure of a Drosophila population for adult locomotor activity

    SciTech Connect

    Grechanyi, G.V.; Korzun, V.M.

    1995-01-01

    Analysis of the variation of adult locomotor activity in four samples taken at different times from a natural population of Drosophila melanogaster showed that the total variation of this trait is relatively stable in time and has a substantial genetic component. Genotypic structure of the population for locomotor activity is characterized by the presence of large groups of genotypes with high and low values of this trait. A possible explanation for the presence of such groups in a population is cyclic density-dependent selection.

  20. Determination of the Spontaneous Locomotor Activity in Drosophila melanogaster

    PubMed Central

    Woods, Jared K.; Kowalski, Suzanne; Rogina, Blanka

    2014-01-01

    Drosophila melanogaster has been used as an excellent model organism to study environmental and genetic manipulations that affect behavior. One such behavior is spontaneous locomotor activity. Here we describe our protocol that utilizes Drosophila population monitors and a tracking system that allows continuous monitoring of the spontaneous locomotor activity of flies for several days at a time. This method is simple, reliable, and objective and can be used to examine the effects of aging, sex, changes in caloric content of food, addition of drugs, or genetic manipulations that mimic human diseases. PMID:24747955

  1. Determination of the spontaneous locomotor activity in Drosophila melanogaster.

    PubMed

    Woods, Jared K; Kowalski, Suzanne; Rogina, Blanka

    2014-01-01

    Drosophila melanogaster has been used as an excellent model organism to study environmental and genetic manipulations that affect behavior. One such behavior is spontaneous locomotor activity. Here we describe our protocol that utilizes Drosophila population monitors and a tracking system that allows continuous monitoring of the spontaneous locomotor activity of flies for several days at a time. This method is simple, reliable, and objective and can be used to examine the effects of aging, sex, changes in caloric content of food, addition of drugs, or genetic manipulations that mimic human diseases. PMID:24747955

  2. Increased novelty seeking and decreased harm avoidance in rats showing Type 2-like behaviour following basal forebrain neuronal loss.

    PubMed

    Johansson, A K; Hansen, S

    2001-01-01

    Previous research has shown that excitotoxic lesions of the septum, ventral striatum and adjacent areas increase alcohol intake and defensive aggression in the rat. This behavioural constellation resembles that observed in early-onset Type 2 alcoholism. Due to the fact that the prototypical Type 2 alcoholic scores high on novelty seeking and low on harm avoidance, we studied these temperamental traits in rats with basal forebrain lesions. In comparison with controls, such rats showed more exploration (nose-poking) of a hole-board (indicating increased novelty seeking) and less risk assessment behaviour (stretched attend posturing) in an unfamiliar arena (indicating reduced harm avoidance). In both tests the experimental rats showed signs of motor restlessness. The results obtained indicate that basal forebrain neuronal loss may be associated with an enhanced exploratory responsiveness to novel stimuli together with a relative freedom of anticipatory anxiety. PMID:11704616

  3. Historical variation of structural novelty in a natural product library.

    PubMed

    Kong, De-Xin; Guo, Ming-Yue; Xiao, Zhi-Hong; Chen, Ling-Ling; Zhang, Hong-Yu

    2011-11-01

    To evaluate the potential of natural products as novel structure suppliers, a historical analysis was performed on the structural novelty of a natural product library, viz., the Chapman & Hall/CRC Dictionary of Natural Products. The results show that although the unexplored natural product universe is still ample, it is more and more difficult to find novel agents from nature, with the discovery probability of novel structures and scaffolds being lower than 50% in the near future, which mainly results from the intrinsic redundancy of natural products and, thus, is unlikely to be reversed merely through technical progresses. PMID:22083910

  4. Amphetamine locomotor sensitization is accompanied with an enhanced high K⁺-stimulated Dopamine release in the rat medial prefrontal cortex.

    PubMed

    Casanova, José Patricio; Velis, Gabriela Paz; Fuentealba, José Antonio

    2013-01-15

    In the present work, we assessed dopamine extracellular levels in the medial Prefrontal Cortex of rats repeatedly treated with amphetamine during early abstinence. Rats were injected once daily with amphetamine for five consecutive days. A sensitized locomotor response was observed in 55% of animals treated. After two days of abstinence, an amphetamine challenge dose was given to all rats and locomotor activity was measured to assess expression of sensitization. A persistence of heightened locomotor response to amphetamine was observed in rats that developed sensitization. Twenty four hours after amphetamine challenge, microdialysis experiments were carried out to evaluate basal and stimulated dopamine extracellular levels in the medial Prefrontal Cortex. Rats that developed and expressed amphetamine locomotor sensitization showed a significantly greater high potassium-stimulated dopamine release compared to Non-sensitized and Saline rats. These results show that the increased dopamine releasability in the medial Prefrontal Cortex occurs soon after development of amphetamine locomotor sensitization, and might be underlying the early expression of sensitization. PMID:23047059

  5. Alterations in locomotor activity after microinjections of GBR-12909, selective dopamine antagonists or neurotensin into the medial prefrontal cortex.

    PubMed

    Radcliffe, R A; Erwin, V G

    1996-06-01

    It has been postulated that increased dopamine (DA) activity in the medial prefrontal cortex (mPFC) exerts an inhibitory influence over DA release in the nucleus accumbens and, thus, also over locomotor activity. Experiments were designed to examine the role of mPFC DA and neurotensin (NT), a neuropeptide which interacts with DA, in spontaneous locomotor activity. LS/IBG mice were injected bilaterally with either GBR-12909, a selective DA uptake blocker, the DA D1 receptor antagonist R-(+)-SCH-23390, the DA D2 receptor antagonist epidepride, NT or a combination of drugs. GBR-12909 produced a U-shaped dose-response curve with a maximum inhibition of 47% of control. Postmortem tissue levels of DA, 5-hydroxytryptamine, norepinephrine and their major metabolites were determined after microinjections of GBR-12909. Tissue levels of these compounds were not significantly affected by GBR-12909. However, the ratios of homovanilic acid/DA and homovanilic acid + 3,4-dihyroxyphenylacetic acid/DA were significantly decreased, whereas the 5-hydroxyindoleacetic acid/5-hydroxytryptamine ratio was not affected by GBR-12909, suggesting a selective effect on DAergic processes. By itself, R-(+)-SCH-23390 had no effect on locomotor activity except at a very high dose which caused locomotor inhibition (49% of control). Epidepride caused a dose-dependent inhibition of locomotor activity with a maximum inhibition of 49% of control. When coinjected with an inhibitory dose of GBR-12909, both epidepride and R-(+)-SCH-23390 attenuated the GBR-12909 effect in a dose-dependent manner. A broad range of doses of NT was found to have no consistent effect on locomotor activity. However, when coinjected with an inhibitory dose of GBR-12909, NT attenuated the GBR-12909-induced inhibition in a dose-dependent manner. The results suggest that stimulation of DA receptors in the mPFC, both DA D1 and DA D2 receptors mediates locomotor inhibition. Furthermore, stimulation of NT receptors appears to

  6. Effects of caffeine and L-phenylisopropyladenosine on locomotor activity of mice

    SciTech Connect

    Buckholtz, N.S.; Middaugh, L.D.

    1987-10-01

    C57BL/6J and DBA/2J mice were used to determine if possible differences in the behavioral response to caffeine might be related to differences in A1 adenosine receptors. Caffeine stimulated locomotor activity of both strains, but the dose-response relationship and time course of drug action differed according to strain. Although their response to caffeine differed, the strains did not differ in response to the A1 adenosine agonist L-phenylisopropyladenosine (PIA) nor in the binding of the A1 agonist (/sup 3/H)N6-cyclohexyladenosine (CHA) in various brain regions. Thus, the behavioral differences in response to caffeine could not be accounted for by differences in adenosine binding. Of alternative mechanisms, strain differences in A2 receptors appear to be the most promising.

  7. Low and high cocaine locomotor responding male Sprague-Dawley rats differ in rapid cocaine-induced regulation of striatal dopamine transporter function.

    PubMed

    Mandt, Bruce H; Zahniser, Nancy R

    2010-03-01

    Adult outbred Sprague-Dawley rats can be classified as either low or high cocaine responders (LCRs or HCRs, respectively). Importantly, LCRs and HCRs are distinguished by their differential responsiveness to acute cocaine-induced (but not baseline) locomotor activity, inhibition of the dopamine transporter (DAT) and resulting extracellular DA (HCR > LCR), as well as by repeated cocaine-induced locomotor sensitization and measures of cocaine's rewarding and reinforcing effects (LCR > HCR). Curiously, 30 min after acute cocaine HCRs exhibit greater DAT-mediated [(3)H]DA uptake into striatal synaptosomes than LCRs. To investigate this finding further, we measured locomotor activity, striatal [(3)H]DA uptake kinetics and DAT cell surface expression in LCRs and HCRs over an extended period (25-180 min) after a single relatively low-dose of cocaine (10 mg/kg, i.p.). HCRs exhibited the "predicted" locomotor response: a marked initial activation that returned to baseline by 120 min post-injection. While LCRs exhibited a >50% lower maximal locomotor response, this increase was sustained, lasting approximately 33% longer than in HCRs. At 25 min post-cocaine, maximal velocity (V(max)) of [(3)H]DA uptake was significantly higher by 25% in HCRs than LCRs, with no difference in affinity (K(m)). Despite the DAT V(max) difference, however, DAT surface expression did not differ between LCRs and HCRs. There was a similar trend (HCR > LCR) for DAT V(max) at 40 min, but not at 150 or 180 min. These findings suggest that, compared to LCRs, HCRs have an enhanced ability to rapidly up-regulate DAT function in response to acute cocaine, which may contribute to their more "normal" cocaine-induced locomotor activation. PMID:19951714

  8. Active Gaze, Visual Look-Ahead, and Locomotor Control

    ERIC Educational Resources Information Center

    Wilkie, Richard M.; Wann, John P.; Allison, Robert S.

    2008-01-01

    The authors examined observers steering through a series of obstacles to determine the role of active gaze in shaping locomotor trajectories. Participants sat on a bicycle trainer integrated with a large field-of-view simulator and steered through a series of slalom gates. Steering behavior was determined by examining the passing distance through…

  9. Acute neuroactive drug exposures alter locomotor activity in larval zebrafish

    EPA Science Inventory

    In an effort to develop a rapid in vivo screen for EPA's prioritization of toxic chemicals, we are characterizing the locomotor activity of zebrafish (Danio rerio) larvae after exposure to prototypic drugs that act on the central nervous system. MPTP (1-methyl-4phenyl- 1 ,2,3,6-...

  10. DRUG EFFECTS ON THE LOCOMOTOR ACTIVITY OF LARVAL ZEBRAFISH.

    EPA Science Inventory

    As part of an effort to develop a rapid in vivo screen for EPA’s prioritization of toxic chemicals, we have begun to characterize the locomotor activity of zebrafish (Danio rerio) larvae and the effects of prototype drugs. Zebrafish larvae (6-7 days post-fertilization) were indiv...