Establishing premises for inter-professional collaborative practice in school: inclusion, difference and influence.

PURPOSE: To ascertain stakeholders' agreement and disagreement about inter-professional collaboration (IPC) when supporting the child with a developmental language disorder (DLD) in school. MATERIALS AND METHODS: Two rounds of an online Delphi survey were undertaken with a purposive sample of 26 participants (researchers, practitioners and parents). Topics were informed by the views of children engaged in an earlier phase of the research. Agreement was set at an inter-quartile range of 1, with level of agreement measured using a five-point semantic differential scale. Qualitative data were examined using content analysis. RESULTS: There was strong agreement across the stakeholder groups about the child-led goals of IPC. Stakeholders also agreed that DLD is best viewed as a learning difference rather than a disorder. We identified ambivalence across the groups about the right of the child with DLD to have influence in decision-making about supports in school. CONCLUSIONS: We propose that IPC should be viewed as a means of ensuring the inclusion of the child in school. A shift in focus from remediating perceived deficits of the child, to affecting change in classroom practice, is also indicated. The need to reinforce the unconditional right of the child to have influence in decisions about supports is highlighted. Implications for IPC when meeting the needs of children with a developmental disability in school are outlined.IMPLICATIONS FOR REHABILITATIONThe goal of inter-professional collaboration should be to ensure the inclusion of the child with a developmental disability in school.Interventions delivered in school should focus on changing practice in the classroom, rather than on the child's perceived deficits.The child with a developmental disability should be given influence in collaborative decision-making to ensure supports are relevant and responsive to their needs.

Comparing the Standard and Electronic Versions of the Alzheimer's Disease Assessment Scale - Cognitive Subscale: A Validation Study.

The Alzheimer's Disease Assessment Scale (ADAS-Cog) has become the de facto gold-standard for assessing the efficacy of putative anti-dementia treatments. There has been an increasing interest in providing greater standardization, automation, and administration consistency to the scale. Recently, electronic versions of the ADAS-Cog (eADAS-Cog) have been utilized in clinical trials and demonstrated significant reductions in frequency of rater error as compared to paper. In order to establish validity of the electronic version (eADAS-Cog), 20 subjects who had received a diagnosis of probable Alzheimer's disease (AD) at a private US Memory Clinic completed a single-center, randomized, counterbalanced, prospective trial comparing a version of the eADAS-Cog to the standard paper scale. Interclass Correlation Coefficient on total scores and Kappa analysis on domain scores yielded high agreement (0.88 - 0.99). Effects of order and mode of administration on ADAS-Cog total scores did not demonstrate a significant main effect. Overall, this study establishes adequate concurrent validity between the ADAS-Cog and eADAS-Cog among an adult population with diagnosed AD.

Engaging multiple stakeholders to improve speech and language therapy services in schools: an appreciative inquiry-based study.

BACKGROUND: Effective collaboration between speech and language therapists (SLTs) and teachers is essential in meeting the needs of children with developmental language disorders in school, but it is difficult to achieve. Currently, many children receive inadequate speech and language therapy services and/or support in school. The aim of this study was to engage key stakeholders (SLTs, teachers, parents and children with DLD) in the co-design of their ideal speech and language therapy service and support in school. The study was undertaken in order to inform the development of a conceptual model to guide collaborative practice when working with this population. METHODS: A qualitative study involving a diverse range of key stakeholders and using appreciative inquiry. This is a method which enables those involved to construct their 'ideal' about a topic of interest. Recruitment was carried out using purposive sampling. We conducted focus groups with practitioners (SLTs and teachers) and parents as well as semi-structured interviews with children who have DLD using 'draw and tell' techniques. A total of five focus groups and nine interviews were conducted with participants (n = 27). RESULTS: The children described their ideal supports as those which enabled them to connect, contribute and achieve. They describe ways in which environmental barriers in school needed to be addressed to allow them to do so. The professionals primarily described ways in which the language skills of the child could be improved. Both parents and practitioner groups described the importance of strengthening networks between service providers and service users. They also highlighted the need to promote a collaborative culture if stakeholders are to work effectively together across sectors. CONCLUSIONS: There were differences in perspectives about the ways in which speech and language therapy services and supports could be improved, demonstrating the importance of engaging a diverse group of stakeholders. Of note were the unique insights the children brought about the barriers they faced as a result of their difficulties. Based on our findings we propose that children should be given influence in decisions about the supports that they receive in school. Implications for policy, research and practice are discussed.

Precipitation and temperature drive continental-scale patterns in stream invertebrate production.

Secondary production, the growth of new heterotrophic biomass, is a key process in aquatic and terrestrial ecosystems that has been carefully measured in many flowing water ecosystems. We combine structural equation modeling with the first worldwide dataset on annual secondary production of stream invertebrate communities to reveal core pathways linking air temperature and precipitation to secondary production. In the United States, where the most extensive set of secondary production estimates and covariate data were available, we show that precipitation-mediated, low-stream flow events have a strong negative effect on secondary production. At larger scales (United States, Europe, Central America, and Pacific), we demonstrate the significance of a positive two-step pathway from air to water temperature to increasing secondary production. Our results provide insights into the potential effects of climate change on secondary production and demonstrate a modeling framework that can be applied across ecosystems.

An ecotoxicological view on neurotoxicity assessment.

The numbers of potential neurotoxicants in the environment are raising and pose a great risk for humans and the environment. Currently neurotoxicity assessment is mostly performed to predict and prevent harm to human populations. Despite all the efforts invested in the last years in developing novel in vitro or in silico test systems, in vivo tests with rodents are still the only accepted test for neurotoxicity risk assessment in Europe. Despite an increasing number of reports of species showing altered behaviour, neurotoxicity assessment for species in the environment is not required and therefore mostly not performed. Considering the increasing numbers of environmental contaminants with potential neurotoxic potential, eco-neurotoxicity should be also considered in risk assessment. In order to do so novel test systems are needed that can cope with species differences within ecosystems. In the field, online-biomonitoring systems using behavioural information could be used to detect neurotoxic effects and effect-directed analyses could be applied to identify the neurotoxicants causing the effect. Additionally, toxic pressure calculations in combination with mixture modelling could use environmental chemical monitoring data to predict adverse effects and prioritize pollutants for laboratory testing. Cheminformatics based on computational toxicological data from in vitro and in vivo studies could help to identify potential neurotoxicants. An array of in vitro assays covering different modes of action could be applied to screen compounds for neurotoxicity. The selection of in vitro assays could be guided by AOPs relevant for eco-neurotoxicity. In order to be able to perform risk assessment for eco-neurotoxicity, methods need to focus on the most sensitive species in an ecosystem. A test battery using species from different trophic levels might be the best approach. To implement eco-neurotoxicity assessment into European risk assessment, cheminformatics and in vitro screening tests could be used as first approach to identify eco-neurotoxic pollutants. In a second step, a small species test battery could be applied to assess the risks of ecosystems.

Disruption of cortical network activity by the general anaesthetic isoflurane.

BACKGROUND: Actions of general anaesthetics on activity in the cortico-thalamic network likely contribute to loss of consciousness and disconnection from the environment. Previously, we showed that the general anaesthetic isoflurane preferentially suppresses cortically evoked synaptic responses compared with thalamically evoked synaptic responses, but how this differential sensitivity translates into changes in network activity is unclear. METHODS: We investigated isoflurane disruption of spontaneous and stimulus-induced cortical network activity using multichannel recordings in murine auditory thalamo-cortical brain slices. RESULTS: Under control conditions, afferent stimulation elicited short latency, presumably monosynaptically driven, spiking responses, as well as long latency network bursts that propagated horizontally through the cortex. Isoflurane (0.05-0.6 mM) suppressed spiking activity overall, but had a far greater effect on network bursts than on early spiking responses. At isoflurane concentrations >0.3 mM, network bursts were almost entirely blocked, even with increased stimulation intensity and in response to paired (thalamo-cortical + cortical layer 1) stimulation, while early spiking responses were <50% blocked. Isoflurane increased the threshold for eliciting bursts, decreased their propagation speed and prevented layer 1 afferents from facilitating burst induction by thalamo-cortical afferents. CONCLUSIONS: Disruption of horizontal activity spread and of layer 1 facilitation of thalamo-cortical responses likely contribute to the mechanism by which suppression of cortical feedback connections disrupts sensory awareness under anaesthesia.

Evidence for Systemic Infection by Puccinia horiana, Causal Agent of Chrysanthemum White Rust, in Chrysanthemum.

Puccinia horiana, causal agent of the disease commonly known as chrysanthemum white rust (CWR), is a quarantine-significant fungal pathogen of chrysanthemum in the United States and indigenous to Asia. The pathogen was believed to have been eradicated in the United States but recently reappeared on several occasions in northeastern United States. The objective of the study presented here was to determine whether P. horiana could systemically infect chrysanthemum plants, thus providing a means of survival through winters. Scanning and transmission electron microscopy revealed the development of P. horiana on the surface and within leaves, stems, or crowns of inoculated chrysanthemum plants artificially exposed to northeastern U.S. winter temperatures. P. horiana penetrated leaves directly through the cuticle and then colonized the mesophyll tissue both inter- and intracellularly. An electron-dense material formed at the interface between fungal and host mesophyll cells, suggesting that the pathogen adhered to the plant cells. P. horiana appeared to penetrate mesophyll cell walls by enzymatic digestion, as indicated by the absence of deformation lines in host cell walls at penetration sites. The fungus was common in vascular tissue within the infected crown, often nearly replacing the entire contents of tracheid cell walls. P. horiana frequently passed from one tracheid cell to an adjacent tracheid cell by penetration either through pit pairs or nonpitted areas of the cell walls. Individual, presumed, fungal cells in mature tracheid cells of the crown and stems arising from infected crowns suggested that the pathogen might have been moving at least partially by means of the transpiration stream. The demonstration that chrysanthemum plants can be systemically infected by P. horiana suggests that additional disease control measures are required to effectively control CWR.

Mechanism of thrombocytopenia in chronic hepatitis C as evaluated by the immature platelet fraction.

INTRODUCTION: Thrombocytopenia occurs frequently in chronic hepatitis C. The mechanism of this association was investigated utilizing the immature platelet fraction (IPF%) as an index of platelet production together with assay of thrombopoietin (TPO). METHODS: In a cross-sectional study, 47 patients with chronic hepatitis C were studied, 29 with thrombocytopenia and 18 without thrombocytopenia (six patients in each group were on interferon therapy). RESULTS: IPF% was elevated in the thrombocytopenic compared with the nonthrombocytopenic group (9.0 ± 4.8% vs. 4.7 ± 2.4%, P < 0.001), and an increase in IPF% was significantly associated with thrombocytopenia on multivariable analysis (P < 0.05). Splenomegaly was more common in thrombocytopenic than in nonthrombocytopenic subjects (66% vs. 6%, P < 0.001), and on multivariable analysis, splenomegaly was the factor associated with the highest relative risk of thrombocytopenia (RR = 1.9, P < 0.05). IPF% values were elevated in a similar proportion of thrombocytopenic patients with and without splenomegaly (58% and 60%, respectively). There was no difference in TPO levels between thrombocytopenic and nonthrombocytopenic patients, and TPO levels were not related to the risk of thrombocytopenia on multivariable analysis. Significantly more thrombocytopenic than nonthrombocytopenic subjects had abnormal liver function tests, cirrhosis, and portal hypertension, and a decrease in serum albumin was significantly associated with thrombocytopenia (P < 0.005) on multivariable analysis. CONCLUSIONS: Factors associated with liver disease in general are associated with thrombocytopenia in chronic hepatitis C. Peripheral platelet destruction or sequestration is the major mechanism for thrombocytopenia, with hypersplenism being an important cause. Low TPO levels were not related to the occurrence of thrombocytopenia in this study.

Activation of dopaminergic neurotransmission in the medial prefrontal cortex by N-methyl-d-aspartate stimulation of the ventral hippocampus in rats.

Many behavioral functions-including sensorimotor, attentional, memory, and emotional processes-have been associated with hippocampal processes and with dopamine transmission in the medial prefrontal cortex (mPFC). This suggests a functional interaction between hippocampus and prefrontal dopamine. The anatomical substrate for such an interaction is the intimate interconnection between the ventral hippocampus and the dopamine innervation of the mPFC. The present study yielded direct neurochemical evidence for an interaction between ventral hippocampus and prefrontal dopamine transmission in rats by demonstrating that subconvulsive stimulation of the ventral hippocampus with N-methyl-d-aspartate (NMDA; 0.5 mug/side) activates dopamine transmission in the mPFC. Postmortem measurements revealed that bilateral NMDA stimulation of the ventral hippocampus, resulting in locomotor hyperactivity, increased the homovanillic acid/dopamine ratio, an index of dopamine transmission, in the mPFC; indices of dopamine transmission in any of five additionally examined forebrain regions (amygdala, nucleus accumbens shell/core, lateral prefrontal cortex, caudate putamen) were unaltered. In vivo microdialysis measurements in freely moving rats corroborated the suggested activation of prefrontal dopamine transmission by demonstrating that unilateral NMDA stimulation of the ventral hippocampus increased extracellular dopamine in the ipsilateral mPFC. The suggested influence of the ventral hippocampus on prefrontal dopamine may be an important mechanism for hippocampo-prefrontal interactions in normal behavioral processes. Moreover, it indicates that aberrant hippocampal activity, as found in neuropsychiatric diseases, such as schizophrenia and mood disorders, may contribute to disruption of certain cognitive and emotional functions which are extremely sensitive to imbalanced prefrontal dopamine transmission.

Evidence that 4-pregnen-17,20beta,21-triol-3-one functions as a maturation-inducing hormone and pheromonal precursor in the percid fish, Gymnocephalus cernuus.

Behavioral, biochemical, and electrophysiological studies suggest that the trihydroxylated progestin steroid, 4-pregnen-17,20beta,21-triol-3-one (20beta-S) stimulates oocyte maturation and pheromone release in the Eurasian ruffe, a freshwater percid fish. Behavioral observations found that female ruffe undergoing oocyte maturation (OM) release a pheromonal cue that stimulates swimming activity and social interactions among conspecific males. Neither vitellogenic nor ovulated females released the cue. Pheromone production was directly associated with elevated plasma levels of 20beta-S in maturing female ruffe which in vitro incubation suggested to be a possible maturation-inducing hormone (MIH) in this species along with 4-pregnen-17,20beta-diol-3-one (17,20betaP). However, neither of these steroids appear to be the pheromone because electrophysiological and behavioral studies found them to lack olfactory (EOG) and behavioral activity. Instead, studies of the odor of steroid-injected fish suggest the pheromone is a metabolite of 20beta-S. In particular, inter-peritoneal injection of 20beta-S (but not 17,20betaP) consistently induced release of a urinary cue with strong behavioral activity. The pheromone may be a highly polar and novel metabolite because it could not be extracted using octadecylsilane resin (C18) which has proven effective for other teleost hormonal pheromones.

The acquisition, retention and reversal of spatial learning in the morris water maze task following withdrawal from an escalating dosage schedule of amphetamine in wistar rats.

Two experiments were carried out to evaluate the effects of amphetamine withdrawal in rats on spatial learning in the water maze. A schedule of repeated d-amphetamine administration lasting for 6 days, with three injections per day (1-5 mg/kg, i.p.), was employed. Experiment 1 demonstrated that amphetamine withdrawal did not impair the acquisition of the water maze task (third to fourth withdrawal days), but amphetamine-withdrawn rats made more target-zone visits and reached the former location of the platform quicker than controls during the probe test (fifth withdrawal day). In experiment 2, retention of the location of the escape platform was assessed in animals having been pre-trained on the water maze task before treatment. On the third withdrawal day, retention of the former platform location was assessed in a probe test. Retention was only clearly seen in the measure of target zone visits, and performance did not differ between groups. Next, the animals were trained to escape to a new location in the water maze on withdrawal days 4-5. A reversal effect could be discerned across the first four trials, as evident by the animals' tendency to search in the former target quadrant. This interfered with the new learning, but amphetamine-withdrawn animals appeared to overcome it more rapidly than saline-treated controls. This finding is consistent with the view that amphetamine withdrawal can enhance behavioural switching, which could be expressed as a reduction of proactive interference during learning; and, it is in line with our previous finding that latent inhibition is also attenuated during amphetamine withdrawal.

Amphetamine withdrawal does not produce a depressive-like state in rats as measured by three behavioral tests.

Administration of amphetamine (AMPH) can induce symptoms of psychosis in humans and locomotor sensitization in rats; in contrast, withdrawal from a period of AMPH intake is most often associated with symptoms of human endogenous depression. The aim of this study was to determine whether AMPH withdrawal produces a depressive-like state in rats. The present study examined the effects of withdrawal from an escalating-dose AMPH schedule (ESC; three daily injections over 6 days, 1-5 mg/kg, i.p.) and an intermittent-dose AMPH schedule (INT; one daily injection over 6 days, 1.5 mg/kg, i.p.) on animals' performance in three behavioral paradigms related to depression: the Porsolt swim test, the learned helplessness assay and operant responding for sucrose on a progressive ratio schedule. ESC and INT AMPH withdrawal had no effect on any of these tests or on stress responsiveness as measured by increased plasma levels of corticosterone (CORT) and adrenocorticotropin following the swim test, although basal CORT levels were higher in AMPH-withdrawn animals compared to controls. Finally, we confirmed the presence of locomotor sensitization for both AMPH schedules after 30 days of withdrawal. Our results suggest that the ability of AMPH withdrawal to produce symptoms of depression may not be evident in all behavioral screens for depressive symptoms in the rat.

A Comparison of Low-Temperature and Ambient-Temperature SEM for Viewing Nematode Faces.

Faces of lesion nematodes Pratylenchus teres (populations RTB and JK) and P. zeae or the bacterivore Distolabrellus veechi were observed on frozen specimens with low-temperature scanning electron microscopy and as chemically fixed, critical-point dried specimens with conventional scanning electron microscopy. Amphidial secretions were preserved in chemically fixed but not cryofixed lesion nematodes. Overhanging liplets of chemically fixed D. veechi may be artifactual because they appeared as variably filled, mostly empty membranes when cryofixed. The diagnostically useful lips of the frozen lesion nematodes exhibited six sectors of variable prominence that were absent in chemically fixed specimens. This variability may be due to different degrees of muscle contraction captured during cryofixation, which occurs in milliseconds. This is the first evidence that rarely observed lip sectors in Pratylenchus may be something other than an artifact of shrinkage.

Increased conditioned fear response and altered balance of dopamine in the shell and core of the nucleus accumbens during amphetamine withdrawal.

It has been suggested that neuroadaptations within the nucleus accumbens (NAC) dopaminergic (DA) projection contribute to the negative affect associated with psychostimulant withdrawal. The present study assessed the effects of amphetamine (AMPH) withdrawal on behavioral and NAC DA responses to conditioned fear stress. Animals injected with escalating-dose AMPH (1-5mg/kg, three injections/day, 6 days) or saline (SAL) acquired a tone-shock association on withdrawal day 3 and were tested for extinction of conditioned freezing to the tone on withdrawal day 4. Extracellular levels of NAC shell and core DA were monitored using in vivo microdialysis on both days. AMPH-withdrawn animals exhibited more conditioned freezing than SAL animals during both acquisition and extinction. During acquisition, DA increased more in the shell than the core of the NAC in both AMPH and SAL groups. During extinction to the tone, shell DA increased in SAL- but not AMPH-treated animals, whereas core DA activity was greater in AMPH than SAL animals. These data demonstrate that AMPH withdrawal alters the balance between shell and core DA transmission while increasing the behavioral expression of conditioned fear. Such drug-induced neuroadaptations in the NAC stress response may be involved in the exacerbation of negative emotions associated with drug withdrawal and stimulant-induced psychosis.

Selective responding of nucleus accumbens core and shell dopamine to aversively conditioned contextual and discrete stimuli.

Dopamine transmission within the nucleus accumbens has been implicated as a neurochemical substrate of associative learning processes. It has been suggested that the acquisition of classically conditioned fear to a specific environment, or context, differs fundamentally from the development of conditioned fear to a discrete stimulus, such as a light or a tone. In this study, we assessed extracellular dopamine in the rat nucleus accumbens shell and core during the expression of a conditioned fear response. Animals were aversively conditioned to either a context or a tone and extracellular dopamine was measured in the nucleus accumbens shell and core by in vivo microdialysis over the next 2 days as animals were returned first to the conditioning chamber (day 1: context test), and subsequently as animals were again returned to the chamber and presented with the conditioned tone stimulus (day 2: tone test). Dopamine levels in the core were significantly higher in the Context-Shock group compared to the Tone-Shock group during the 30-min exposure to context while dopamine levels in the nucleus accumbens shell did not differ significantly during the context test between groups. In contrast, extracellular dopamine in the shell but not the core of Tone-Shock animals increased significantly during presentation of the tone. Dopamine in both the shell and core remained unchanged during the tone test in the Context-Shock groups.These data suggest distinct roles for shell and core dopamine transmission in the expression of a conditioned emotional response. While dopamine increased in the shell primarily during the presentation of a discrete tone conditioned stimulus, core dopamine responded more to a contextual conditioned stimulus. These results may reflect differences in either the type of information acquired or the salience of the learned associations which are formed to a context vs. a discrete tone cue.

Effects of psychostimulant withdrawal on latent inhibition of conditioned active avoidance and prepulse inhibition of the acoustic startle response.

RATIONALE: Chronic intermittent administration of amphetamine and cocaine can precipitate psychotic episodes in humans and produce persistent behavioral changes (i.e. increased locomotion, stereotypy) in the rat. The psychostimulant sensitization model of psychosis holds that the repeated administration of drugs such as amphetamine and cocaine induces long-lasting neuroadaptations and behavioral outcomes in animals that parallel aspects of the schizophrenic condition. OBJECTIVES: In the present study, we attempted to validate this model further by examining the effects of short-term withdrawal from repeated administration of cocaine and amphetamine on performance in two animal behavioral models of cognitive deficits found in schizophrenia: latent inhibition and prepulse inhibition. Reductions in both of these behavioral phenomena have been reported in schizophrenic patients and in acutely amphetamine-treated rats. METHODS: Animals were tested after 4 days of withdrawal from 5 days of daily systemic 20 mg/kg cocaine or 1.5 mg/kg amphetamine injections for either latent inhibition of two-way active avoidance acquisition or prepulse inhibition of an acoustic startle response. RESULTS: Our results indicate that, rather than reducing the expression of these behaviors, withdrawal from either cocaine or amphetamine enhanced the expression of latent inhibition of the active avoidance response while having no effect on prepulse inhibition of acoustic startle. CONCLUSIONS: These data indicate that although the sensitized response to amphetamine and cocaine administration may model some aspects of schizophrenic psychosis, behaviors exhibited by sensitized animals in the absence of an acute drug challenge are not consistent with models of the positive symptoms of schizophrenia.

Interactions between environmental stimulation and antipsychotic drug effects on forebrain c-fos activation.

The immediate-early gene product Fos is differentially induced in the rat brain by the antipsychotic drugs haloperidol and clozapine. It is often claimed that although both drugs induce Fos in the nucleus accumbens, haloperidol but not clozapine increases Fos-like immunoreactivity in the striatum, whereas clozapine but not haloperidol increases Fos-like immunoreactivity in prefrontal cortex. Investigations of antipsychotic drug effects on Fos have typically administered high doses with pronounced sedative effects to behaviorally naive animals. In the present study, we compared the effects of low doses of haloperidol (0.1 mg/kg) and clozapine (5 mg/kg) on Fos-like immunoreactivity in rats which were either behaviorally naive, exposed to a novel environment or tested for two-way active avoidance. We determined that haloperidol increased Fos in the striatum and nucleus accumbens regardless of testing condition whereas clozapine markedly reduced the induction of Fos by behavioral testing in these regions; moreover, haloperidol dramatically increased prefrontal cortical Fos expression in animals placed in a novel environment, but not in testing-naive controls. From these results we suggest that antipsychotic drug-induced patterns of Fos expression in the rat are highly dependent on animals' concurrent behavioral status, perhaps reflecting neuroanatomically specific interactions between antipsychotic drugs and environmental stressors which also may occur in the schizophrenic condition.

Putative steroidal pheromones in the round goby, Neogobius melanostomus: olfactory and behavioral responses.

To identify potential hormonal pheromones of the round goby (Neogobius melanostomus), a species recently introduced to the Great Lakes, we used electro-olfactogram (EOG) recording to examine olfactory responsiveness to more than 100 steroids and prostaglandins. Neogobius detected free and conjugated 18-, 19- and 21-carbon steroids, but did not detect prostaglandins. EOG cross-adaptation, used to determine if Neogobius can discriminate the detected compounds at the sensory level, suggested that the detected steroids act on four classes of olfactory receptor mechanisms named (according to the most potent ligand for each): estrone, 17 beta-estradiol-3 beta-glucuronide, etiocholanolone, and dehydroepiandrosterone-3-sulfate. Although none of the detected steroids induced reproductive behaviors, exposure to steroids from three of the four receptor classes (estrone, 17 beta-estradiol-3 beta-glucuronide, or etiocholanolone) increased ventilation rate in males, whereas only etiocholanolone increased ventilation rate in females. Using the ventilation increase as a behavioral bioassay of steroid detection, behavioral cross-adaptation studies in males demonstrated that steroids discriminated at the sensory level are also discriminated behaviorally. These findings suggest the round goby may use steroids as putative pheromones.

Acute withdrawal from repeated cocaine treatment enhances latent inhibition of a conditioned fear response.

Psychostimulant-induced locomotor sensitization and disrupted latent inhibition (LI) of a classically conditioned association are two paradigms that have been widely studied as animal behavioural models of psychosis. In this study we assessed the effects of withdrawal from the repeated intermittent administration of cocaine on LI of a conditioned fear response. Animals which were either preexposed (PE) to a tone conditioned stimulus (CS) or naive to the tone (i.e. non-preexposed: NPE) subsequently experienced 10 pairings of the tone CS with footshock. Afterwards, both groups received five daily injections of cocaine (20 mg/kg, i.p.) or saline. After 3 days of withdrawal from drug treatment, animals were tested for conditioned freezing to the context of the footshock chamber, and 1 day later, for conditioned freezing to the tone CS. Cocaine-sensitized animals exhibited markedly enhanced LI compared to saline-treated animals, due to the fact that NPE-cocaine animals spent more time freezing during the tone CS than NPE-saline animals, whereas PE-cocaine animals showed a tendency toward reduced freezing compared to the saline groups. While these results suggest the presence of increased anxiety in cocaine-withdrawn NPE animals, the absence of this effect in cocaine-withdrawn PE rats indicates that cocaine withdrawal also influences the retrieval of previously learned information.