Anxiolytic effects of cytotoxic hippocampal lesions in rats.

Rats with cytotoxic lesions of the hippocampus were given 3 anxiety tests: social interaction with a novel rat, the elevated zero-maze (a modification of the plus-maze), and hyponeophagia (eating familiar and novel foods in a novel place). Marked anxiolytic effects were seen in the social interaction and hyponeophagia tests, but not on the zero-maze. These results confirm and extend previous experiments that used traditional lesion techniques. The zero-maze result was consistent with other experiments using the plus-maze, in which intrahippocampal administrations of pharmacological agents were not anxiolytic, although variability in ethological tests may also be a factor. As the hyponeophagia test used an elevated apparatus, as in the zero- and plus-mazes, the lack of a lesion effect in the zero-maze was unlikely to have been due to an inability to relieve height-induced anxiety. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nicotine's enhancing effects on responding maintained by conditioned reinforcers are reduced by pretreatment with mecamylamine, but not hexamethonium, in rats.

Several studies have indicated that nicotine increases responding maintained by conditioned reinforcers. We assessed the effects of subcutaneous injections of 0.3 mg/kg nicotine and two nicotinic antagonists on responding maintained by conditioned and primary reinforcers and responding during extinction in 8 Long Evans rats. Mecamylamine, a central and peripheral nicotinic antagonist, and hexamethonium, a peripheral nicotinic antagonist, were administered prior to a subset of the experimental sessions. Nicotine selectively increased responding maintained by conditioned reinforcers and mecamylamine, but not hexamethonium, attenuated this effect. These results suggest that nicotine's enhancing effect on responding maintained by conditioned reinforcers is mediated in the central nervous system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Noninteractive effects of diazepam and amygdaloid lesions in two animal models of anxiety.

The role of the amygdala in mediating the anxiolytic effects of diazepam was examined in 2 models of rat anxiety. As in previous experiments (e.g., C. Pesold and D. Treit; see PA, Vol 80:4610; Treit et al; see PA, Vol 80:36896), amygdaloid lesions by themselves did not increase rats' exploration of the open arms of the elevated plus-maze or decrease rats' burying of an electrified probe in the shock-probe burying test. However, amygdaloid lesions did increase rats' shock-probe contacts. Diazepam (2 mg/kg) increased open-arm activity and decreased burying behavior to an equal extent in sham-lesioned and amygdala-lesioned rats and had no significant effect on the facilitation of probe contacts induced by amygdaloid lesions. These results suggest that many of the anxiolytic effects of benzodiazepines are not mediated by the amygdala. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of hypnotically induced anxiety on the Manifest Anxiety Scale and the Barron Ego-Strength Scale.

A measure of hypnotically-induced anxiety was correlated with scores on Taylor's Manifest Anxiety Scale and Barron's Ego-Strength Scale. A positive relationship was elicited between degree of experienced anxiety and the Taylor scale; a negative relationship between anxiety and Barron's scale. "These results suggest that the MAS is a valid indicator of clinical anxiety… [and] that the… [Barron scale] is genuinely measuring ego-strength or some similar trait associated with psychopathological conditions." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of self-reported and observed job conditions on depression and anxiety symptoms: A comparison of theoretical models.

The demand/control/support and effort/reward imbalance models have relied on self-reported methods to describe how poor psychosocial working conditions lead to harmful health outcomes. The hindrance/utilization model uses an observational methodology to assess these relationships. Cross-sectional observational and self-reported data from 98 civil servants participating in the Whitehall II Study of British civil servants were used to test whether work conditions measured by each of the three theoretical models explained a significant amount of the variance in depression and anxiety symptoms. Observational measures were also used to assess potential common methods variance bias between the self-reported job conditions and the outcomes. Results showed that the demand/control/support model explained the most variance in depression and anxiety symptoms and the associations were not wholly due to common methods variance. Moreover, measures associated with job resources (e.g., skill discretion, social support and skill utilization) had a protective effect on depression and anxiety symptoms. Exertion-related conditions (e.g., demands, effort, over commitment) were not consistently associated with depression or anxiety symptoms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Amygdala and Ventral Hippocampus Contribute Differentially to Mechanisms of Fear and Anxiety.

Cytotoxic ventral hippocampal lesions produced anxiolytic effects on 4 ethologically based, unconditioned tests of anxiety in the rat (hyponeophagia, black/white 2-compartment box test, a successive alleys test that represents a modified version of the elevated plus-maze, and a social interaction test). Dorsal hippocampal lesions did not produce anxiolytic effects on these tests, suggesting a distinct specialization of function within the hippocampus. Furthermore, the effects of ventral hippocampal lesions were also distinct from those of amygdala lesions. This suggests that the effects of ventral hippocampal lesions are not simply due to direct or indirect effects on the amygdala, and that these 2 brain areas contribute differentially to a brain system (or systems) associated with the processing of fearful and/or anxiogenic stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of GABA and anxiety in the reconsolidation of conditioned fear.

The current study examined the effects of systemic administration of a GABA agonist [midazolam (MDZ)] and a GABA antagonist (bicuculline) on fear responding after brief CS exposure, a procedure thought to involve memory reconsolidation. Using a contextual fear-conditioning paradigm, rats were initially given two context-shock training trials, followed 24 hrs later by a 90-s context exposure (reactivation), and 24 hrs later by a 3-min context test. In Experiment 1, MDZ (2 mg/kg, i.p.), whereas in Experiment 2, bicuculline (1 mg/kg, i.p.), was administered immediately after reactivation. MDZ reduced conditioned freezing, whereas bicuculline only marginally potentiated conditioned freezing. The MDZ fear disruption effect did not occur in the absence of reactivation, and was evident 10 days after the initial test. Experiment 3 induced high levels of baseline anxiety using the single prolonged stress paradigm, and replicated the essential procedure of Experiment 1. Results indicated that MDZ fear disruption did not differ between high and low anxiety rats. The data suggest the involvement of GABA receptors in reconsolidation processes, and the possible clinical use of MDZ in fear reduction with brief reexposure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychopharmacological effects of oxycodone in volunteers with and without generalized anxiety disorder.

A number of studies have documented a relationship between anxiety disorders and opioid misuse and abuse, and there is some data to suggest that some people use opioids in an attempt to reduce their anxiety. We tested the hypothesis that volunteers with an anxiety disorder would report a more positive spectrum of subjective effects (i.e., greater ratings of drug liking and wanting to take the drug again) from oxycodone, a mu opioid agonist, than would volunteers without the disorder, and that oxycodone would have greater reinforcing efficacy in volunteers with the anxiety disorder. In addition to subjective and reinforcing effects, the psychomotor and physiological effects of oxycodone also were assessed. Individuals with generalized anxiety disorder (GAD, n = 8) and nonanxious controls (CTL, n = 8) were administered 0, 10, and 20 mg oxycodone (per os) in 3 separate sessions. Oxycodone produced a number of effects in a dose-related fashion in both groups. However, on several subjective effects measures, only CTL participants reported effects of oxycodone (e.g., high, lightheaded). Neither group had statistically significant increases in peak liking or “take drug again” ratings in the oxycodone conditions relative to the placebo condition, and in neither group did the drug function as a reinforcer, as measured by the Multiple-Choice Procedure (Griffiths, Troisi, Silverman, & Mumford, 1993). Anxiety ratings were low in the GAD group (in the absence of drug), and this may have lessened the possibility of detecting a more positive spectrum of oxycodone effects in this group than in the CTL group. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Structure of anxiety symptoms in urban children: Competing factor models of Revised Children's Manifest Anxiety Scale.

The Revised Children's Manifest Anxiety Scale (RCMAS; C. R. Reynolds & B. 0. Richmond, 1985) is among the most widely used self-report measures of children's anxiety. The authors compared its current empirically derived factor structure with theory-driven models derived from 8 experts on child anxiety using concept mapping. Confirmatory factor analyses compared models using data from 898 seventh graders in an urban public school system serving a high percentage of African Americans. The most parsimonious best-fitting model was an expert-derived model with factors reflecting anxious arousal, social evaluation–oversensitivity, worry, and a higher order factor. This model was theoretically meaningful, excluded items less relevant to anxiety, and was invariant across gender. Future research with the RCMAS should consider use of these dimensions. The combination of qualitative and quantitative methodology used in this study appeared to have considerable utility for refining measures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reasoning rats: Forward blocking in Pavlovian animal conditioning is sensitive to constraints of causal inference.

Forward blocking is one of the best-documented phenomena in Pavlovian animal conditioning. According to contemporary associative learning theories, forward blocking arises directly from the hardwired basic learning rules that govern the acquisition or expression of associations. Contrary to this view, here the authors demonstrate that blocking in rats is flexible and sensitive to constraints of causal inference, such as violation of additivity and ceiling considerations. This suggests that complex cognitive processes akin to causal inferential reasoning are involved in a well-established Pavlovian animal conditioning phenomenon commonly attributed to the operation of basic associative processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavioral effects of intracerebroventricular microinfusion of agmatine in adult rats.

The present study investigated the behavioral effects of intracerebroventricular microinfusion of agmatine. Rats with low dose (10 μg), but not high dose (100 μg), of agmatine spent significantly less time in the enclosed arm and more time in the open arm in the elevated plus maze. In the water maze task, the high dose group displayed a transient impairment in searching for a hidden platform, whereas the low dose group had reduced latency in the first probe test. In the object recognition task, all groups could detect the novel object, but the low dose group spent significantly more time exploring displaced objects. Furthermore, the low dose group made significantly fewer errors in the working, but not the reference, memory version of the radial arm maze task. These results suggest that the behavioral effects of agmatine are task- and dose-dependent, and agmatine may be an anxiolytic and memory modulator. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Compensatory nicotine self-administration in rats during reduced access to nicotine: An animal model of smoking reduction.

The ability of smoking reduction (e.g., decreasing cigarettes per day) to produce significant reductions in toxin exposure is limited by compensatory increases in smoking behavior. Characterizing factors contributing to the marked individual variability in compensation may be useful for understanding this phenomenon. The goal of the current study was to develop an animal model of smoking reduction and to begin to examine potential behavioral and pharmacokinetic contributors to compensation. Rats trained for nicotine self-administration (NSA) in unlimited access sessions were exposed to a progressive decrease in duration of access to nicotine from 23-hr/day to 10-, 6-, and 2-hr/day. Following a return to 23 hr/day access and extinction, single-dose nicotine pharmacokinetic parameters were determined. Rats exhibited a reduction in total daily nicotine intake during reduced access to NSA, but decreases in nicotine intake were not proportional to decreases in access duration. Compensatory increases in hourly infusion rate were also observed when access was decreased. The magnitude of compensation differed considerably among animals. Early session infusion rate during baseline was significantly correlated, while nicotine clearance was moderately correlated, with 1 measure of compensation. Infusion rates were transiently increased compared to prereduction levels when unlimited access was restored, and this effect was greatest in animals that had exhibited the greatest levels of compensation. These findings indicate that rats exhibit compensatory increases in NSA during reduced access to nicotine, with substantial individual variability. This model may be useful for characterizing underlying factors and potential consequences of compensatory smoking. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reinforcing effects of diazepam under anxiogenic conditions in individuals with social anxiety.

Diazepam (DZ) reinforcement was tested under anxiogenic (public speaking) and neutral (computer task) conditions. Individuals with social anxiety disorder (n=11) and healthy controls (n=11) participated in two 5-session phases. Each phase used a standard choice procedure (2 sample, 3 choice sessions) comparing 10-mg DZ and placebo. During the public speaking condition, DZ preference was greater among the participants with social anxiety compared with controls (81.8% vs. 36.4%; p     

Applying a cognitive behavioral model of health anxiety in a cancer genetics service.

A cognitive-behavioral model of health anxiety was used to investigate reactions to genetic counseling for cancer. Participants (N = 218) were asked to complete a questionnaire beforehand and 6 months later. There was an overall decrease in levels of cancer-related anxiety, although 24% of participants showed increased cancer-related anxiety at follow-up. People who had a general tendency to worry about their health reported more cancer-related anxiety than those who did not at both time points. This health-anxious group also showed a postcounseling anxiety reduction, whereas the others showed no significant change. Participants with breast or ovarian cancer in their family were more anxious than participants with colon cancer in their family. Preexisting beliefs were significant predictors of anxiety, consistent with a cognitive-behavioral approach. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The facets of anxiety sensitivity represented in the Childhood Anxiety Sensitivity Index: Confirmatory analyses of factor models from past studies.

Results of past factor analytic studies of the Childhood Anxiety Sensitivity Index and Anxiety Sensitivity Index were used to formulate hypotheses about factor models of anxiety sensitivity. Using a nonclinical sample of 767 children and adolescents and confirmatory factor analysis, hypothesized models with 2, 3, and 4 lower order factors (facets) were tested. Goodness-of-fit criteria indicated that a model with 4 facets fits these data well. Support was found for factorial invariance of the 4 facets across age and gender, using nonclinical and clinical samples. Results support a hierarchical factor model in that there was a strong general factor, explaining 71% of the variance. Findings are discussed in the context of anxiety sensitivity theory and research with children and adolescents. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of FG7142 on two types of forgetting in 18-day-old rats.

The authors studied the role of gamma-aminobutyric acid (GABA) in 2 types of forgetting of fear in the developing rat. One type of forgetting studied was that observed after an intermediate retention interval (the "Kamin effect"); the other type studied was that observed after a longer interval (infantile amnesia). Rats were given pairings of an auditory conditioned stimulus with shock, and learned fear was assessed by freezing. Forgetting at an intermediate retention interval (1 hr) was not alleviated by the GABAA receptor partial inverse agonist FG7142 (0, 1, 5, or 10 mg/kg), whereas forgetting at a longer retention interval (48 hr) was alleviated. These results suggest that in the developing rat, forgetting observed at different retention intervals is mediated by different physiological mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Genetic differences in startle gating-disruptive effects of apomorphine: Evidence for central mediation.

Strain differences in sensitivity to dopamine agonist-induced disruption of prepulse inhibition (PPI) may be a useful model for the genetics of PPI deficits in neuropsychiatric disorders. Compared with Long-Evans (LE) rats, Sprague-Dawley (SD) rats are more sensitive to the PPI-disruptive effects of the DA agonist apomorphine. The authors tested the hypothesis that this strain difference reflects brain function rather than peripheral physiology. Significant SD > LE PPI-disruptive effects of apomorphine were observed despite equal apomorphine levels in SD and LE rats in forebrain regions that regulate PPI. SD > LE PPI-disruptive effects of apomorphine were also independent of peripheral versus central route of administration. This model for PPI genetics is sensitive to differences in central rather than peripheral substrates. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relations of positive and negative affectivity to anxiety and depression in children: Evidence from a latent variable longitudinal study.

The tripartite model of anxiety and depression has been studied with adults; however, support is still emerging with children concerning measurement and relations between positive (PA) and negative (NA) affect and psychopathology. In this longitudinal study of 270 4th- to 11th-grade children (mean age=12.9 years, SD=2.23), confirmatory factor analysis supported a 2-factor orthogonal model of children's self-reported affect and revealed that the concurrent relations of NA and PA to anxiety and depression symptoms were consistent with the tripartite model. Structural equation modeling demonstrated moderate cross-time stability of trait PA and NA, consistent with a temperament view of these factors, as well as partial support for the role of NA and PA in the development of anxiety and depression symptoms in children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differential genetic regulation of motor activity and anxiety-related behaviors in mice using an automated home cage task.

Traditional behavioral tests, such as the open field test, measure an animal's responsiveness to a novel environment. However, it is generally difficult to assess whether the behavioral response obtained from these tests relates to the expression level of motor activity and/or to avoidance of anxiogenic areas. Here, an automated home cage environment for mice was designed to obtain independent measures of motor activity levels and of sheltered feeding preference during three consecutive days. Chronic treatment with the anxiolytic drug chlordiazepoxide (5 and 10 mg/kg/day) in C57BL/6J mice reduced sheltered feeding preference without altering motor activity levels. Furthermore, two distinct chromosome substitution strains, derived from C57BL/6J (host strain) and A/J (donor strain) inbred strains, expressed either increased sheltering preference in females (chromosome 15) or reduced motor activity levels in females and males (chromosome 1) when compared to C57BL/6J. Longitudinal behavioral monitoring revealed that these phenotypic differences maintained after adaptation to the home cage. Thus, by using new automated behavioral phenotyping approaches, behavior can be dissociated into distinct behavioral domains (e.g., anxiety-related and motor activity domains) with different underlying genetic origin and pharmacological responsiveness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessing worry in older adults: Confirmatory factor analysis of the Penn State Worry Questionnaire and psychometric properties of an abbreviated model.

The assessment of worry among older adults typically has involved measures designed with younger cohorts. Because of special concerns in assessing older adults, modifications to existing instruments may be necessary. Addressing equivocal factor analytic data on the Penn State Worry Questionnaire (PSWQ) among younger adults, the authors conducted confirmatory factor analyses to evaluate the generalizability of previous models to older adults with generalized anxiety disorder. Data fit poorly with established single- and two-factor models. The single-factor model was modified, resulting in the elimination of 8 items, strong fit indices, high internal consistency, adequate test-retest reliability, and good convergent and divergent validity. Further psychometric work is required to assess whether the revised model is a more parsimonious method to assess late-life anxiety. (PsycINFO Database Record (c) 2010 APA, all rights reserved)