Effect of aceclidine on scopolamine- and electroshock-induced amnesia in rats

It is found that the cholinomimetic aceclidine stimulates learning and memory processes and exerts antiamnestic effect in rats with conditioned avoidance reaction. The effect of aceclidine is not inferior to that of amiridin and surpasses that of physostigmine. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 3, pp. 296–298, March, 1997     

Defining age limits of the sensitive period for attachment learning in rat pups

Enhanced odor preference learning and attenuated fear learning characterizes rat pups' attachment learning Sensitive Period for learning the maternal odor. This period terminates at 10 days old (PN10) with increasing endogenous levels of the stress hormone, corticosterone. Increasing Sensitive Period pups' corticosterone prematurely terminates the Sensitive Period, while decreasing corticosterone in older pups delays Sensitive Period termination. Here we extend these findings and define the age range corticosterone alters learning and question whether corticosterone permanently terminates the Sensitive Period. Pups were odor‐0.5 mA shock conditioned with either corticosterone increased (PN5–6; 4 mg/kg vs. saline) or decreased (PN15–16; naturally by maternal presence or corticosterone synthesis blocker, Metyrapone). Finally, PN7–8 pups were conditioned with corticosterone and reconditioned without corticosterone to assess whether the Sensitive Period was permanently terminated. Results indicate developmental limits for corticosterone regulation of pup learning are PN6 through PN15. Furthermore, inducing precocious corticosterone induced fear learning was not permanent, since reconditioning without corticosterone enabled odor preference learning. Results suggest pups are protected from learning aversions to maternal odor until approaching weaning. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 52: 453–460, 2010.     

Can overeating induce conditioned taste avoidance in previously food restricted rats?

While feeding is rewarding, the feeling of satiation has been theorized to have a mixed affect. Using a food restriction model of overeating we examined whether bingeing was capable of supporting conditioned taste avoidance (CTA). Adult male Sprague-Dawley rats were maintained on either an ad lib (n = 8) or restricted (50% of regular consumption; n = 24) food access for 20 days. On Days 9, 14, and 19 all rats were given access to a novel saccharin solution in place of water, and two groups of food restricted rats were given access to either 100% of regular food consumption or ad lib food. Ad lib access in the restricted rats induced significant overeating on all three exposures. After all rats were returned to ad lib feeding, a 24 h two-bottle saccharin/water choice test displayed significantly reduced saccharin consumption in the overeating rats, compared to those in the other 3 groups. To determine whether this avoidance was due to a learned association, a second experiment used a latent inhibition paradigm, familiarizing half the rats with the saccharin for 8 days prior to pairing it with overeating. Using the design of Experiment 1, with only the continuously ad lib and the restricted to ad lib feeding groups, it was found that the overeating-induced saccharin avoidance was attenuated by the pre-exposure. These results suggest that self-induced overeating is capable of supporting a learned avoidance of a novel solution suggestive of a conditioned satiety or taste avoidance.     

大一新生社交回避与苦恼的现状及其与人格的相关性研究

目的了解大学新生社交回避及苦恼状况,探讨社交回避及苦恼与人格的关系。方法采用艾森克人格问卷简式量表(EPQ-RSC)、社交回避及苦恼量表(SADS)为调查工具,对随机抽取的某医学院2008级临床、护理专业280名本科生进行调查,数据进行t检验、Pearson相关分析、多元逐步回归分析。结果 1大一新生社交回避及苦恼、社交回避、社交苦恼均处于中等水平;2社交回避及苦恼、社交回避、社交苦恼与内外倾(E)、神经质(N)、掩饰性(L)相关显著;3逐步多元回归结果发现,E、N、L为新生社交回避及苦恼的有效预测因素。结论新生社交回避及苦恼状况处于中等水平;人格是影响社交回避及苦恼的重要因素。     

Air and shock two-way shuttlebox avoidance in C57BL/6J and 129X1/SvJ mice

Despite multiple advantages of the use of electric shock as an aversive stimulus, reasons exist for considering alternative aversive stimuli. In the present study, we examined and compared the acquisition of two-way shuttlebox avoidance with 275.8-kPa (40-psi) pulsed air and continuous 0.4-mA shock in two strains of mice commonly employed in targeted gene mutation research, C57BL/6J and 129X1/SvJ. Each trial consisted of a 5-s warning stimulus (WS, light) during which shuttling to the other side cancelled delivery of the aversive stimulus. Once initiated, the aversive stimulus remained active for 20 s or until an escape response occurred. For C57BL/6J mice, air and shock were equally and highly effective aversive stimuli. In contrast, air was less effective than shock for 129X1/SvJ mice. C57BL/6J mice outperformed 129X1/SvJ mice for both stimulus types. For 129X1/SvJ mice, longer escape latencies were observed initially for air, suggesting that shock is more effective. However, these differences in latency dissipated within the first seven sessions. Nevertheless, by the end of the 17-day study, asymptotic levels of avoidance proficiency were substantially lower for air than for shock in 129X1/SvJ mice. These results indicate that air is a suitable substitute for shock as an aversive stimulus in shuttlebox active avoidance; however, the relative efficacies of these aversive stimuli appear to depend upon the strain chosen for study.     

The impact of illness‐related shame on psychological health and social relationships: Testing a mediational model in students with chronic illness

This study explores the impact of illness‐related shame on the quality of social relationships and psychological health in chronic patients. We aimed to examine the roles of fear of receiving compassion from others and experiential avoidance as potential mediators of this relationship. Although some studies have demonstrated the negative impact of chronic illness‐related shame on psychological functioning, the mechanisms that may underlie this link remain understudied. The sample was comprised by 115 college students, which had been diagnosed with at least 1 chronic illness. Participants completed self‐report measures on an online platform. This study's design was cross‐sectional. A path analysis was conducted using structural equation modelling. Results showed that the impact of illness‐related shame on both psychological health (R² = .45) and the quality of social relationships (R² = .33) was fully accounted by fear of compassion from others and experiential avoidance. This model revealed an excellent fit. Fear of receiving compassion from others was the main mediator of the illness‐related shame link with the quality of social relationships (β = ?.22). The main mediator of the association between shame‐related chronic illness and psychological health was experiential avoidance (β = ?.21).This study shed light on possible psychological mechanisms linking feelings of shame associated with having a chronic condition and impaired social relationships and mental health. On one hand, resisting feelings of compassion and care from others and, on the other hand, avoiding difficult internal experiences and situations that might trigger them seem to underlie the impact of shame on psychological and social functioning in chronic patients.     

Natural activation of caspase-3 is required for the development of operant behavior in postnatal ontogenesis

We have previously demonstrated transient increases in caspase-3 activity in the hippocampus of rat pups from age 17 days. We report here our studies on the effects of inhibition of caspase-3 during this period on the acquisition of a two-way avoidance reaction. Rat pups received intracerebroventricular doses of the caspase-3 inhibitor Z-DEVD-FMK On postnatal day 18. Control animals of the same age received the inactive peptide Z-FA-FMK or isotonic saline solution. Inhibition of caspase-3 during the period of its natural activation in the hippocampus during early ontogenesis was found to impair the development of operant behavior in rats. This was apparent as a reduction in the efficiency of learning during acquisition of active avoidance reactions and decreases in the numbers of intersignal reactions. Administration of the inhibitor had no specific action on the types of conditioned reflex activity less associated with operant learning. Thus, there were no differences between the experimental and control groups in the numbers of emotional reactions to the conditioned stimulus. The number of orientational-investigative conditioned reactions also showed no change after administration of Z-DEVD-FMK. On the background of the reduction in the efficiency of the acquisition of the conditioned active avoidance reflex, the number of incomplete acts, in contrast to other types of conditioned reactions, increased significantly after administration of Z-DEVD-FMK, which is evidence for the persistence of the ability to form associative connections between activation of the conditioned signal and the need to move to the other sector. The difficulty in these animals arose at the decision-taking stage on choosing the appropriate form of behavior. Changes in orientational-investigative behavior were not associated with inhibition of caspase-3 during the critical period of development, as the effects of Z-DEVD-FMK and Z-FA-FMK were similar. Translated from Zhurnal Vysshei Nervnoi Deyatel'nosti imeni I. P. Pavlova, Vol. 57, No. 6, pp. 702–711, November–December, 2007.     

Attention orienting by another's gaze direction in children with autism

BACKGROUND: The aim of this study was to investigate attention orienting triggered by another's gaze direction in autism. METHOD: Twelve high-functioning children with autism and gender- and age-matched normal control children were studied using two tasks. In the first task, children were asked to detect laterally presented target stimuli preceded by centrally presented facial cue stimuli in which gaze was either straight ahead or averted. The direction of the cue was either congruent, neutral, or incongruent with respect to the laterality of the target stimulus. In the second task, children were asked to discriminate the direction of eye gaze. RESULTS: The results showed that another person's static gaze direction triggered an automatic shift of visual attention, both in children with autism and in normally developing children. The children in both groups were also able to overtly discriminate the direction of the gaze. CONCLUSION: These results seem to suggest that, in children with autism, the visual system processes information about another person's gaze direction and sends this information to those areas that subserve reflexive attention orienting. However, future studies are needed to investigate whether the processing of eyes and gaze direction relies on similar neural mechanisms in children with autism and in normally developing children.     

Robust coupling of body movement and gaze in young infants

In the first few months after birth, rapid bursts of body movement precede and possibly facilitate shifts of gaze during free looking, with potential consequences for perception and cognition. Here we report that the characteristic features of movement-gaze coupling found during free looking are preserved when attention is perturbed by a salient change in the visual environment. Twenty-four 3-month-olds looked at two attractive 3-dimensional objects while body movement and corneal reflections of the objects were recorded. Lateral head movement was measured offline. After approximately 2 s of looking at one stimulus, the nonfixated stimulus either began to rotate back and forth (distracter events) or remained motionless (control events). In distracter events, the motion of the nonfixated stimulus triggered substantial motor quieting, shortened the duration of the look, and shortened the time to reorient gaze compared to control events. Abbreviated motor quieting and small increases in lateral head movement occurred during control events at the same time in the look as the protracted motor quieting and increased head movement in distracter events. Despite these perturbations, the characteristic bursts of body movement that precede shifts of gaze during free looking occurred in both distracter and control events. The results demonstrate the robust nature of early movement-gaze coupling, raise questions about the specific role of attention in the dynamic links between body movement and gaze, and highlight the potential short and long term functional significance of movement-gaze-attention coupling.