Effects of subchronic phencyclidine on behaviour of female rats on the elevated plus maze and open field

YesFemale hooded-Lister rats received either sub-chronic phencyclidine (PCP) (2 mg/kg, n=20) or vehicle (1 ml/kg, n=20) i.p. twice daily for seven days, followed by a seven-day washout period. Rats were challenged with acute PCP or vehicle and tested for locomotor activity to ensure hyperactivity was observed in the sub-chronic PCP treated rats. Rats were then tested on the elevated plus maze and in an open field for 10 minutes. Sub-chronic PCP did not significantly affect behaviour on the elevated plus maze or in the open field. In conclusion, sub-chronic PCP does not induce anxiety-like behaviour

On the concept of “Comprehensiveness” in Information Services: The case of the online translation aid and hosting service Minna no Hon'yaku / Kyo Kageura and Takeshi Abekawa

The aim of this research is to clarify the concept of ―comprehensiveness‖ and its relationship to the concept of ―normativeness‖ in language reference tools and information for online translators, from the point of view of strategically providing useful reference information via a translation aid-service. The concept of ―comprehensiveness‖ in reference information has not been explored fully to dateThe questions to be answered are: What are the factors that determine different levels of ―comprehensiveness‖ and ―normativeness‖? How can ―comprehensiveness‖ be classified in relation to different types of reference lookup, and what kind of strategies can we define and adopt in developing and providing useful reference resources automatically or semi-automatically? While it is widely held that careful user studies are important in the strategic design of information services, empirical studies of potential users are not sufficient in the conceptualisation and development of advanced information services and tools which incorporate innovative functions or features, because quite frequently users do not understand what they want from the new information technologies. This is all the more true for issues in which one or more of the key concepts are not understood clearly. The question we wished to address fall precisely within this category, as the concept of ―comprehensiveness‖ has not yet been explored fully. We therefore took a deductive and analytical approach, firstly listing up the factors that affect the concept of ―comprehensiveness‖ and related concepts, with special reference to the translation-aid site Minna no Hon'yaku (translation of/by/for all: http://trans-aid.jp/), and deriving the classification of and desiderata for language reference tools and information from the objective of helping online translators. Although we adopted an analytical and deductive approach, the whole argument is implicitly supported by our own experience with actual translators' behaviour on the site Minna no Hon'yaku. Results of the analysis revealed that, within a framework of providing language reference tools for translators in general and in the context of the online translation-aid environment in particular, three different types of combinations of ―comprehensiveness‖ and ―normativeness‖ are of prominence and importance, namely: (i) task-oriented normativeness/comprehensiveness; (ii) domain-oriented normativeness/comprehensiveness; and (iii) user-oriented normativeness/comprehensivenes

The Hand Sees Visual Periphery Better Than the Eye: Motor-Dependent Visual Motion Analyses

Information pertaining to visual motion is used in the brain not only for conscious perception but also for various kinds of motor controls. In contrast to the increasing amount of evidence supporting the dissociation of visual processing for action versus perception, it is less clear whether the analysis of visual input is shared for characterizing various motor outputs, which require different kinds of interactions with environments. Here we show that, in human visuomotor control, motion analysis for quick hand control is distinct from that for quick eye control in terms of spatiotemporal analysis and spatial integration. The amplitudes of implicit and quick hand and eye responses induced by visual motion stimuli differently varied with stimulus size and pattern smoothness (e.g., spatial frequency). Surprisingly, the hand response did not decrease even when the visual motion with a coarse pattern was mostly occluded over the visual center, whereas the eye response markedly decreased. Since these contrasts cannot be ascribed to any difference in motor dynamics, they clearly indicate different spatial integration of visual motion for the individual motor systems. Going against the overly unified hierarchical view of visual analysis, our data suggest that visual motion analyses are separately tailored from early levels to individual motor modalities. Namely, the hand and eyes see the external world differently

Distant Co-occurrence Patterns of Connectives: a Corpus Study of Formulaicity in Japanese

Using corpus research methods, this study aims to establish whether there are two-item and, more generally, multi-item distant co-occurrence patterns of connectives in written Japanese, and further, to clarify the role these patterns play in discourse. The study is based on a hybrid corpus of written Japanese including Humanities and social science papers, Science and technology papers, and general written language data. The co-occurrence threshold was set at co-occurrence frequency > 10, PMI value > 2, and Dice coefficient > 0.01. The distribution of the observed co-occurring pairs differed according to the genre. Visualization of the connectivity potential of co-occurring pairs as directed graphs showed that these co-occurring pairs constitute longer co-occurrence chains which can be interpreted as ready-made co-occurrence patterns. Two-item and multi-item co-occurrence patterns are considered a type of Bourdieu’s habitus and contribute to both discourse development and discourse prediction

Disentangling the visual, motor and representational effects of vestibular input

The body midline provides a basic reference for egocentric representation of external space. Clinical observations have suggested that vestibular information underpins egocentric representations. Here we aimed to clarify whether and how vestibular inputs contribute to egocentric representation in healthy volunteers. In a psychophysical task, participants were asked to judge whether visual stimuli were located to the left or to the right of their body midline. Artificial vestibular stimulation was applied to stimulate the vestibular organs. We found that artificial stimulation of the vestibular system biased body midline perception. Importantly, no effect was found on motor effector selection. We also ruled out additional explanations based on allocentric visual representations and on potential indirect effects caused by vestibular-driven movements of the eyes, head and body. Taken together our data suggest that vestibular information contributes to computation of egocentric representations by affecting the internal representation of the body midline

Methamphetamine withdrawal induces activation of CRF neurons in the brain stress system in parallel with an increased activity of cardiac sympathetic pathways.

Methamphetamine (METH) addiction is a major public health problem in some countries. There is evidence to suggest that METH use is associated with increased risk of developing cardiovascular problems. Here, we investigated the effects of chronic METH administration and withdrawal on the activation of the brain stress system and cardiac sympathetic pathways. Mice were treated with METH (2 mg/kg, i.p.) for 10 days and left to spontaneous withdraw for 7 days. The number of corticotrophin-releasing factor (CRF), c-Fos, and CRF/c-Fos neurons was measured by immunohistochemistry in the paraventricular nucleus of the hypothalamus (PVN) and the oval region of the bed nucleus of stria terminalis (ovBNST), two regions associated with cardiac sympathetic control. In parallel, levels of catechol-o-methyl-transferase (COMT), tyrosine hydroxylase (TH), and heat shock protein 27 (Hsp27) were measured in the heart. In the brain, chronic-METH treatment enhanced the number of c-Fos neurons and the CRF neurons with c-Fos signal (CRF+/c-Fos+) in PVN and ovBNST. METH withdrawal increased the number of CRF+neurons. In the heart, METH administration induced an increase in soluble (S)-COMT and membrane-bound (MB)-COMT without changes in phospho (p)-TH, Hsp27, or pHsp27. Similarly, METH withdrawal increased the expression of S- and MB-COMT. In contrast to chronic treatment, METH withdrawal enhanced levels of (p)TH and (p)Hsp27 in the heart. Overall, our results demonstrate that chronic METH administration and withdrawal activate the brain CRF systems associated with the heart sympathetic control and point towards a METH withdrawal induced activation of sympathetic pathways in the heart. Our findings provide further insight in the mechanism underlining the cardiovascular risk associated with METH use and proposes targets for its treatment

Modeling “psychosis” in vitro by inducing disordered neuronal network activity in cortical brain slices

# The Author(s) 2009. This article is published with open access at Springerlink.com Introduction Dysregulation of neuronal networks has been suggested to underlie the cognitive and perceptual abnor-malities observed schizophrenia. Discussions An in vitro model of psychosis is proposed based on the two different approaches to cause aberrant networ

Animal models of cognitive dysfunction and negative symptoms of schizophrenia: focus on NMDA receptor antagonism

YesCognitive deficits in schizophrenia remain an unmet clinical need. Improved understanding of the neuro- and psychopathology of these deficits depends on the availability of carefully validated animal models which will assist the development of novel therapies. There is much evidence that at least some of the pathology and symptomatology (particularly cognitive and negative symptoms) of schizophrenia results from a dysfunction of the glutamatergic system which may be modelled in animals through the use of NMDA receptor antagonists. The current review examines the validity of this model in rodents. We review the ability of acute and sub-chronic treatment with three non-competitive NMDA antagonists; phencyclidine (PCP), ketamine and MK801 (dizocilpine) to produce cognitive deficits of relevance to schizophrenia in rodents and their subsequent reversal by first- and second-generation antipsychotic drugs. Effects of NMDA receptor antagonists on the performance of rodents in behavioural tests assessing the various domains of cognition and negative symptoms are examined: novel object recognition for visual memory, reversal learning and attentional set shifting for problem solving and reasoning, 5-Choice Serial Reaction Time for attention and speed of processing; in addition to effects on social behaviour and neuropathology. The evidence strongly supports the use of NMDA receptor antagonists to model cognitive deficit and negative symptoms of schizophrenia as well as certain pathological disturbances seen in the illness. This will facilitate the evaluation of much-needed novel pharmacological agents for improved therapy of cognitive deficits and negative symptoms in schizophrenia

Redox dysregulation, neuroinflammation, and NMDA receptor hypofunction: A "central hub" in schizophrenia pathophysiology?

Accumulating evidence points to altered GABAergic parvalbumin-expressing interneurons and impaired myelin/axonal integrity in schizophrenia. Both findings could be due to abnormal neurodevelopmental trajectories, affecting local neuronal networks and long-range synchrony and leading to cognitive deficits. In this review, we present data from animal models demonstrating that redox dysregulation, neuroinflammation and/or NMDAR hypofunction (as observed in patients) impairs the normal development of both parvalbumin interneurons and oligodendrocytes. These observations suggest that a dysregulation of the redox, neuroimmune, and glutamatergic systems due to genetic and early-life environmental risk factors could contribute to the anomalies of parvalbumin interneurons and white matter in schizophrenia, ultimately impacting cognition, social competence, and affective behavior via abnormal function of micro- and macrocircuits. Moreover, we propose that the redox, neuroimmune, and glutamatergic systems form a "central hub" where an imbalance within any of these "hub" systems leads to similar anomalies of parvalbumin interneurons and oligodendrocytes due to the tight and reciprocal interactions that exist among these systems. A combination of vulnerabilities for a dysregulation within more than one of these systems may be particularly deleterious. For these reasons, molecules, such as N-acetylcysteine, that possess antioxidant and anti-inflammatory properties and can also regulate glutamatergic transmission are promising tools for prevention in ultra-high risk patients or for early intervention therapy during the first stages of the disease