The Smell Identification Test as a measure of olfactory identification ability in schizophrenia and healthy populations: a Rasch psychometric study

This study examines University of Pennsylvania Smell Identification Test (UPSIT; R. L. Doty, 1995) performance in 133 controls and 54 chronic, medicated outpatients with schizophrenia (SZ) using item-response theory modeling. Results show that UPSIT items contribute to 1 factor, cover a range of 8 standard errors of measurement, and articulate 3 ability levels. Although it is not difficult enough to discriminate among persons of above-average ability, the test has diagnostic utility in detecting moderate impairment. Independent of item difficulty, 13 items differentiate patients from controls. When 45 patients and 45 controls were matched on gender and age, patient accuracy remained significantly reduced. The findings support the test's utility and demonstrate how traditional data analysis is insensitive to complexities in test performance.     

Promoting spiritual well-being: a quasi-experimental test of an element of Hay and Nye’s theory of children’s spirituality

This study is one of the first tests of key implicit claims of Hay and Nye’s theory of children’s spirituality and spiritual development. Two quasi-experimental studies tested two claims: that exposure to six conditions posited as fostering relational consciousness in a programme of spiritual formation promotes spiritual well-being; that the effect of the conditions continues after exposure ends. The results for Study One revealed that length of exposure to any of the six conditions was not a significant predictor of spiritual well-being, F(3, 179)?=?1.49, p = 0.22. Study Two results indicated that as the length of time since exposure increased so did spiritual well-being, r(38)?=?0.39, p = 0.01 at the bivariate level, and F(4, 35)?=?2.4, p = 0.06 in the regression. These results reveal a possible relationship between exposure to the six conditions and spiritual well-being.     

Cytokine-Purine Interactions in Behavioral Depression in Rats

This paper reviews recent findings from our laboratories concerning metabolic and immune mediators of behavioral depression in rats. Specifically, a single injection of 6 mg/kg of reserpine substantially increases behavioral depression, as evidenced by an increase in the amount of time spent floating by independent groups of rats tested for swim performance at various times during the next week. The behavioral impairment consists of two components. An early component emerges one hour after reserpine treatment and persists for about 24 hours. The deficit is not reversed by intracranial ventricular infusion of the receptor antagonist for interleukin-1beta (IL-1beta). A second, late-component deficit appears approximately 48 hours after reserpine treatment and recovers within a week. Late-component depression is reversed by central infusion of the IL-1beta receptor antagonist, and is mimicked by central infusion of the proinflammatory cytokine. Importantly, both early and late components of reserpine-induced depression and IL-1beta induced depression are reversed by a systemic injection of the highly selective A2A adenosine receptor antagonist 8-(3-Chlorostyryl) caffeine. These data are discussed in terms of the overlap in the conservation-withdrawal reaction during sickness, traumatic stress, and major depression and the regional contribution of purines and cytokines to the organization of this reaction in the brain.     

Brief flight to a familiar enclosure in response to a conditional stimulus in rats

The authors observed brief, directed movement to a familiar enclosure in rats to determine whether this behavior is part of a rat's defensive repertoire when exposed to a conditional-fear stimulus. In Experiment 1, upon exposure to the compound conditional-fear stimulus of tone and light, only rats that received paired presentations of the conditional stimuli and shock fled into a small, familiar enclosure where they then froze. Rats that had received unpaired presentations did not enter the enclosure in significant amounts when later tested. In Experiment 2, the authors observed rats' freezing and use of either a familiar or an unfamiliar enclosure when tested with a conditional-fear stimulus. Rats tested with a familiar enclosure entered it more quickly than did rats without prior exposure to the enclosure. Freezing was greatest when both training and testing environments were similar with respect to access to the enclosure. The results of these 2 experiments support the idea that brief, directed flight in rats is a component of the postencounter stage of predatory imminence (M. S. Fanselow & L. S. Lester, 1988) and is compatible with freezing.     

Spinal and locus coeruleus noradrenergic lesions abolish the analgesic effects of 5-methoxy-N,N-dimethyltryptamine

Two experiments were performed on Sprague-Dawley rats to study the effects of noradrenaline and 5-hydroxytryptamine depletion upon the antinociceptive effects of acute 5-methoxy-N,N-dimethyltryptamine (5-MeODMT) administration. 6-Hydroxydopamine-induced lesions following microinjections to either the locus coeruleus or the spinal cord (lumbar) abolished completely 5-MeODMT-induced analgesia in the tail-flick, hot-plate, and shock titration tests whereas 5,7-dihydroxytryptamine-induced lesions of the nucleus raphe magnus and the lumbar spinal cord attenuated 5-MeODMT analgesia in the tail-flick and shock titration tests. Thus, the experiments serve to demonstrate an important interaction between descending noradrenergic and serotonergic pathways, possibly at a spinal locus.     

Modeling signal features of escape response: effects of cessation conditioning in "learned helplessness" paradigm

Six experiments examined the effects of signaling the termination of inescapable shock (cessation conditioning) or shock-free periods (backward conditioning) on later escape deficits in the learned helplessness paradigm, using rats (Sprague-Dawley and Bantin-Kingman). A cessation signal prevented later performance deficits when highly variable inescapable shock durations were used during pretreatment. The inclusion of short minimum intertrial intervals during pretreatment did not alter the benefits of cessation conditioning but eliminated the protection afforded by a safety signal. The beneficial effects of both cessation and backward signals were eliminated when a single stimulus signaled shock termination and a shock-free period. Finally, a combination of cessation and backward signals was found to be most effective in immunizing against the effects of subsequent unsignaled, inescapable shock on later escape performance. These data suggest that cessation conditioning may be crucial to the prophylactic action of an escape response.