Microinjections of the dopamine D2 receptor antagonist sulpiride into the medial prefrontal cortex attenuate glucocorticoid-induced impairment of long-term memory retrieval in rats

We recently reported that blockade of dopamine (DA) D2 receptors attenuated deficits in long-term memory retrieval induced by a systemic injection of corticosterone, but the anatomical sites of such interaction were not known. In this study, we investigated whether the DA D2 receptors located in the medial prefrontal cortex (mPFC) may play a role in the impairing effects of glucocorticoids on the memory retrieval process. Young adult male rats were trained in a one trial inhibitory avoidance task (0.5 mA, 3s footshock). On the retention test given 48 h after training, the latency to re-enter the dark compartment and the time spent in light compartment of the apparatus were recorded. Systemically administered corticosterone (1mg/kg) given to rats 30 min before retention testing impaired their memory retrieval. Bilateral microinjections of the DA D2 receptor antagonist sulpiride (10 or 100 ng/0.5 microl per side) into the mPFC 30 min before corticosterone administration attenuated the glucocorticoid-induced impairment of memory retrieval. Furthermore, applied doses of sulpiride alone were ineffective in modulating memory retrieval. These findings indicate that D2 receptors located in the mPFC play an important role in mediating the impairing effects of glucocorticoids on memory retrieval.     

Are Religious People More Prosocial? A Quasi-Experimental Study with Madrasah Pupils in a Rural Community in India

Using quasi-experimental data, this article examines the relationship between religiosity and prosocial behavior. In contrast to previous studies that identify religious people by how often they attend religious services or by their self-reported religiosity, this study compares the behavior of highly devout students who are preparing to enter the clergy to the behavior of other students in a public goods game and in the dictator game. The results show that religious students were significantly more cooperative in the public goods game and significantly more generous in the dictator game than other students.     

Factor-analytic structures in the English and Japanese versions of the Objective Measure of Ego-Identity Status (OMEIS)

This research describes an exploratory factor analysis for the purposes of factorial validation for both the English and Japanese versions of the Objective Measure of Ego-Identity Status (OMEIS)—Ideological version (Adams, Bennion, & Huh, 1989). The Japanese OMEIS is a direct translation of the English OMEIS (Ohnishi, 1998). The study reports the factor structure of the OMEIS—Ideological version in English and Japanese. A principal factor analysis (PFA) with both oblique and orthogonal solutions was performed. Alpha reliabilities for the factors are presented. The present research compares and contrasts the factor structures of OMEIS—Ideological version, derived from a U.S. sample and a Japanese sample, comprising women from late adulthood to middle age. Cultural differences between the two sample populations are explored.     

The laterality of dreaming

The cortical locus of dream generation could be lateralized to the right or left hemisphere, or be bilaterally represented with either equal or unequal contributions from each hemisphere. In this paper we review the neurological literature for cases of loss or alteration of dream report after brain damage. The distribution of lesion sites is used to test the various hypotheses concerning the laterality of dreaming. The hypothesis receiving best support is that dreaming is lateralized to the left hemisphere in individuals with typical neurologic organization.     

Visual angle of the mind's eye before and after unilateral occipital lobectomy.

Do mental images occur in a spatially mapped (i.e., analog, or array-format) representational medium? Kosslyn's (1978) method was used to measure the visual angle of "the mind's eye" to estimate the extent of the imagery medium before and after unilateral occipital lobectomy. It was found that the overall size of the largest possible image was reduced following the surgery. In addition, only the horizontal extent, and not the vertical extent, of the imagery medium was reduced. Finally, it was determined that the S understood the tasks, was not aware of our predictions, and was unaffected by a strong demand characteristic in a different imagery task. These results are consistent with the hypothesis that imagery occurs in a spatially mapped representational medium dependent on occipital cortex.     

Gender differences in depressive response: The role of social support

The present study investigated the possibility that women's ruminative response style to stressful events is due in part to differential advice that women and men receive from their social support networks. Undergraduates (60 men, 136 women) of various ethnic backgrounds (e.g., 21.4% English, 16.8% West Indian, 12.8% Chinese, 10.7% Italian) indicated the extent to which they would endorse various statements of advice for a stimulus person described as experiencing a negative life event. As predicted, subjects endorsed more ruminative advice for female stimulus persons than for male stimulus persons (p< .02). These findings imply that, since females in stressful situations seem more likely to receive ruminative advice than do their male counterparts, women's greater vulnerability to depressive symptoms may be partly the result of the concomitant dangers of stressful events and potentially harmful advice.     

应激对大鼠行为和部分脑区谷氨酸含量的影响

以旷场试验法测定动物在急、慢性躯体性和心理性应激时的行为变化,以快速断头冷冻匀浆法,用ＨＩＴＡＣＨＩ－８３５氨基酸分析仪测定应激各期视皮层、海马、下丘脑、小脑谷氨酸含量。并对正常动物经侧脑室微量注射Ｌ－ＡＰ４后观察行为变化。结果显示,急性应激期动物行为活动增加,慢性应激期减少：应激时,大鼠部分脑区的谷氨酸含量与对照组相比在不同时期呈显著性差异;侧脑室微量注射Ｌ－ＡＰ４提示行为活动减弱可能与脑内Ｇｌｕ系统的活动有关。     

Effects of fasting on visual flicker fusion

Two experiments are reported which investigated the effects of fasting on visual flicker fusion (VFF). In Exp. 1 the VFF of 40 undergraduate students, 20 men and 20 women, whose mean age was 22.5 yr., was measured in nonfasting conditions 1 to 2 weeks before and in fasting conditions during the Muslim fasting month of Ramadan. In Exp. 2 the VFF of a comparable group of 15 men and 15 women, whose mean age was 23.2 yr., was measured in a different month in both fasting and nonfasting conditions. Subjects were assigned randomly to these two conditions. Analysis shows that fasting reduced VFF significantly in both experiments. This finding indicates that fasting is likely to reduce perceptual sensitivity. The results were explained in terms of fatigue and physical exhaustion effects produced by fasting.