In Vivo Hippocampal Acetylcholine Release During Exposure to Acute Stress

Hippocampal extracellular acetylcholine (ACh) and choline levels were evaluated using in vivo microdialysis in male Fischer 344 rats before, during, and following an 80-min exposure to two different stress conditions. Measurements were taken in rats restrained and immersed in a water bath containing either 37 degreesC (normothermic-restraint) or 20 degreesC (cold-restraint) water. Results were compared to normothermic-freely-moving rats. Cold-restrained rats displayed decreased ACh levels during cold exposure relative to both normothermic-restrained and normothermic-freely-moving rats. By the end of the cold exposure period and following removal from cold, ACh levels had returned to near-baseline values. Normothermic-restrained rats had levels similar to those of normothermic-freely-moving rats, except for a marked increase in ACh following removal from restraint. Cold-restrained rats displayed a gradual elevation in choline levels during cold stress, followed by a gradual decline after stress termination, whereas both normothermic-restrained and normothermic-freely-moving rats displayed gradual decreases during the microdialysis session. These findings demonstrate that central cholinergic neurotransmission can be altered by the application of, and removal from, acute stressors. In addition, the results suggest a possible relationship between the magnitudes of both the stressor and its cholinergic consequences.     

Aspects of preschoolers' comprehension of indoor and outdoor gender-typed toys

Forty-nine 44- to 81-month-old predominantly white children's classification of and clustering in recall of gender-typed indoor and outdoor toys, and their gender schematicity, were assessed. Consistent with predictions, children high in gender schematicity demonstrated significantly greater clustering in their recall by gender type than children low in schematicity. As expected, all children demonstrated more accurate classification of same-sex than other-sex gender-typed toys in general. However, boys and girls showed distinctively different patterns in their abilities to accurately classify same-sex and other-sex indoor and outdoor gender-typed toys. Results are discussed in terms of the different social and play contexts inhabited by preschool boys and girls.Completion of this project was facilitated by funds received when the author was a National Institute of Mental Health Postdoctoral Fellow at the University of Denver; Grant 5T32 MH 15780-09, in addition to an Academic Challenge Award from the University of Toledo. This support is gratefully acknowledged. Special thanks to Maryjo Jones for her data collection efforts and to the faculty, children, and parents of Iliff Preschool of Denver, Colorado, and especially to Director Jean True for assisting in the completion of this research. Thanks also to Joan M. Barth, Narina N. Nightingale, Kathy A. Park, and Peg Hull-Smith for their comments on earlier versions of this article. A shorter version of this paper was presented at the Conference on Human Development, Richmond, Virginia, March 1990.To whom reprint requests should be addressed at Department of Psychology, University of Wyoming, P.O. Box 3415, Room 135 Biological Sciences Building, Laramie, WY 82071-3415.     

Are variations among right-handed individuals in perceptual asymmetries caused by characteristic arousal differences between hemispheres?

We propose that much of the variance among right-handed subjects in perceptual asymmetries on standard behavioral measures of laterality arises from individual differences in characteristic patterns of asymmetric hemispheric arousal. Dextrals with large right-visual-field (RVF) advantages on a tachistoscopic syllable-identification task (assumed to reflect characteristically higher left-hemisphere than right-hemisphere arousal) outperformed those having weak or no visual-field asymmetries (assumed to reflect characteristically higher right-hemisphere than left-hemisphere arousal). The two groups were equal, however, in asymmetries of error patterns that are thought to indicate linguistic or nonlinguistic encoding strategies. For both groups, relations between visual fields in the ability to discriminate the accuracy of performance followed the pattern of syllable identification itself, suggesting that linguistic and metalinguistic processes are based on the same laterally specialized functions. Subjects with strong RVF advantages had a pessimistic bias for rating performance, and those with weak or no asymmetries had an optimistic bias, particularly for the left visual field (LVF). This is concordant with evidence that the arousal level of the right hemisphere is closely related to affective mood. Finally, consistent with the arousal model, leftward asymmetries on a free-vision face-processing task became larger as RVF advantages on the syllable task diminished and as optimistic biases for the LVF, relative to the RVF, increased.     

Risk perception of a chronic threat of terrorism: Differences based on coping types,gender and exposure

High levels of risk perception of terrorism (RPT) may impair an individual's quality of life and welfare. To understand the mechanisms responsible for RPT, this study investigated the association of gender and coping styles with individual differences in two key elements of RPT: perceived control and perceived vulnerability. A convenience sample of 400 Israelis (181 men and 219 women) filled out questionnaires on sociodemographic background, RPT and coping. Employing a multidimensional approach for coping, we divided participants into four coping types: problem-focused (n = 65), emotion-focused (n = 70), mixed (n = 122) and minimal (n = 142). The results indicate that problem-focused coping is associated with higher levels of perceived control than other types of coping and mixed coping is associated with higher levels of perceived vulnerability than other coping strategies. Also, interactions between gender and exposure to terrorism contributed to understanding the differences in perceived control. The discussion addresses gender differences in RPT and coping in the context of traditional gender roles. The study concludes with implications for risk management and therapeutic interventions regarding high levels of fear of terrorism.