CB1 cannabinoid receptors modulate kinase and phosphatase activity during extinction of conditioned fear in mice

Cannabinoid receptors type 1 (CB1) play a central role in both short-term and long-term extinction of auditory-cued fear memory. The molecular mechanisms underlying this function remain to be clarified. Several studies indicated extracellular signal-regulated kinases (ERKs), the phosphatidylinositol 3-kinase with its downstream effector AKT, and the phosphatase calcineurin as potential molecular substrates of extinction behavior. To test the involvement of these kinase and phosphatase activities in CB1-dependent extinction of conditioned fear behavior, conditioned CB1-deficient mice (CB1(-/-)) and wild-type littermates (CB1(+/+)) were sacrificed 30 min after recall of fear memory, and activation of ERKs, AKT, and calcineurin was examined by Western blot analysis in different brain regions. As compared with CB1(+/+), the nonreinforced tone presentation 24 h after auditory-cued fear conditioning led to lower levels of phosphorylated ERKs and/or calcineurin in the basolateral amygdala complex, ventromedial prefrontal cortex, dorsal hippocampus, and ventral hippocampus of CB1(-/-). In contrast, higher levels of phosphorylated p44 ERK and calcineurin were observed in the central nucleus of the amygdala of CB1(-/-). Phosphorylation of AKT was more pronounced in the basolateral amygdala complex and the dorsal hippocampus of CB1(-/-). We propose that the endogenous cannabinoid system modulates extinction of aversive memories, at least in part via regulation of the activity of kinases and phosphatases in a brain structure-dependent manner.     

The role of affordances in inhibition of return

Inhibition of return (IOR) is a response delay that occurs when the target is preceded by an irrelevant stimulus (cue) at the same location. IOR can be object based, as well as location based. The aim of the present study was to investigate the role of the pragmatic features of a visually presented object in causing IOR. Two experiments were carried out using different objects as stimuli, for which the graspable part (affordance) was clearly defined. The presentation of a whole object, with the part commonly used to grasp it located below, served as a cue. The presentation of either the graspable or the ungraspable part of the cued or uncued object served as the target Results showed that responses were slower when the graspable part was shown in the cued location than when the ungraspable part was shown in the same location. The effect was apparently linked to the kind of action necessary to grasp an object.     

Activation of the cannabinoid receptor type 1 decreases glutamatergic and GABAergic synaptic transmission in the lateral amygdala of the mouse

The endogenous cannabinoid system has been shown recently to play a crucial role in the extinction of aversive memories. As the amygdala is presumably involved in this process, we investigated the effects of the cannabinoid receptor agonist WIN 55,212-2 (WIN-2) on synaptic transmission in the lateral amygdala (LA) of wild-type and cannabinoid receptor type 1 (CB1)-deficient mice. Extracellular field potential recordings and patch-clamp experiments were performed in an in vitro slice preparation. We found that WIN-2 reduces basal synaptic transmission and pharmacologically isolated AMPA receptor- and GABA_A receptor-mediated postsynaptic currents in wild-type, but not in CB1-deficient mice. These results indicate that, in the LA, cannabinoids modulate both excitatory and inhibitory synaptic transmission via CB1. WIN-2-induced changes of paired-pulse ratio and of spontaneous and miniature postsynaptic currents suggest a presynaptic site of action. Inhibition of G_i/o proteins and blockade of voltage-dependent and G protein-gated inwardly rectifying K⁺ channels inhibited WIN-2 action on basal synaptic transmission. In contrast, modulation of the adenylyl cyclase-protein kinase A pathway, and blockade of presynaptic N- and P/Q- or of postsynaptic L- and R/T-type voltage-gated Ca²⁺ channels did not affect WIN-2 effects. Our results indicate that the mechanisms underlying cannabinoid action in the LA partly resemble those observed in the nucleus accumbens and differ from those described for the hippocampus.     

The Dependency–Counterdependency Dynamic: Interactive Effects of System Justification and Power-Distance Orientation on Radicalization against the Political System

System Justification Theory posits that individuals are less prone to engage in radical action against a system on which they depend. In the present research, we investigated how the association between system-justifying tendencies and radical intentions is moderated by individuals' orientation towards power differentials, namely their “power distance.” A stronger power distance orientation implies that individuals perceive power differentials as a fixed feature of society, curtailing prospects for change. We hypothesized that, at lower levels of power distance orientation, system-justification tendencies would be associated with reduced radical intentions. We contend this will occur because individuals feel dependent on a system perceived as malleable (dependency hypothesis). Conversely, at higher levels of power distance orientation, we expected system-justification tendencies to be associated with stronger radical intentions. We argue that this effect reflects the rejection of dependency on a system perceived as fixed (counterdependency hypothesis). This dependency-counterdependency dynamic was tested using a multigroup latent structural equation model and samples from four countries (N_Total = 2,502), South Korea, Italy, the United Kingdom, and the United States. Results were consistent with the hypothesized dynamic across all countries. Theoretical implications of the findings, limitations, and future research directions are discussed.     

Organizational identification as a trigger for personal well-being: Associations with happiness and stress through job outcomes

Recent literature highlights that well-being, happiness, as well as personal stress, has become important for guiding public policy in areas that might involve suboptimal behaviour. Positive life outcomes can extend from one field of life (family, work, sport, children, hobbies, etc.) to another, multiplying success, performance, and health. In the present study, we aimed to verify whether the positive relation between organizational identification and employees' experiences then extends also into a positive association with more general well-being that is unrelated to the work context. For this purpose, we considered two proxies of organizational well-being: job satisfaction (on the positive side) and turnover intention (on the negative side) as well as the distal associations with happiness. The study involved 305 workers who completed a questionnaire made up of five scales: organization identification, job satisfaction, turnover intention, happiness, and personal stress. We found that organizational identification is positively related to employees' job satisfaction and negatively related to their intention to leave. Afterwards, job satisfaction and turnover intention were related to personal stress and happiness, suggesting a positive effect of organizational identification above and beyond the work context.     

The effects of phonological similarity on the semantic categorisation of pictorial and lexical stimuli: evidence from continuous behavioural measures

Behavioural and neuroimaging studies provide evidence of automatic activation of phonology (e.g., covert speech) during the recognition of lexical stimuli. Implicit processing of phonological information was investigated in a kinematic study of semantic categorisation of pictures (session A) or words (session B). Participants clicked one of two items (target and distractor) based on their semantic congruency (artefact or natural) with a cued-word. Phonological similarity between cued-word and distractor was varied. The presence of the phonological distractor produced trajectories with greater curvature towards the competing semantic category than did the presence of a distractor not phonologically related. This suggests that the semantic categorisation of pictorial and lexical stimuli is influenced by the automatic activation of phonological information. Trajectories’ curvature reveals competition between partially activated phonological and semantic representations suggesting that phonological codes involved in linguistic processing influence the dynamic competition underlying the semantic categorisation of lexical and pictorial.     

Psychological Adjustment,Social Responsiveness and Parental Distress in an Italian Sample of Siblings of Children with High-Functioning Autism Spectrum Disorder

The psychosocial adjustment of siblings of children with autism spectrum disorder (ASD) is a relatively recent field of study, but results in literature are often inconsistent, and studies specifically focused on samples of siblings of children with high-functioning ASD are very few. This paper analyzes the level of social impairment (index of broader autism phenotype), the risk of internalizing and externalizing problems (index of psychological adjustment) and the parenting distress in an Italian sample of siblings of children with high-functioning ASD (n = 26). The presence of risk factors (birth order, sex and number of siblings in the family) and the role of the siblings’ age are also explored. The data were collected through self-report instruments administered to parents. The results do not show higher average risk levels for psychosocial adjustment problems, even though a minority of the cases is at risk for social impairments (7.7 %), internalizing (23.1 %), externalizing (3.8 %) and total difficulties (11.5 %) and for distress in the parent–child system (15 %). Distress in the parent-sibling system seems to be modulated by the sibling’s features and to be higher when the sibling is older than the child with ASD. Additionally, a link between difficulties in psychological adjustment and broader autism phenotype is suggested.     

A STIT Logic for Reasoning About Social Influence

In this paper we propose a method for modeling social influence within the STIT approach to action. Our proposal consists in extending the STIT language with special operators that allow us to represent the consequences of an agent’s choices over the rational choices of another agent.     

Cross‐national comparisons of attitudes towards suicide and suicidal persons in university students from 12 countries

This paper reports the results of a comparative investigation of attitudes to suicide and suicidal persons in 5,572 university students from 12 countries. Participants filled out two scales measuring attitudes towards suicide and suicidal persons, a measure of psychological distress together with the questions about suicidal behavior. Results showed that the highest suicide acceptance scores were observed in Austrian, UK, Japanese and Saudi Arabian samples and the lowest scores were noted in Tunisian, Turkish, Iranian and Palestinian samples. While the highest social acceptance scores for a suicidal friend were noted in Turkish, US, Italian and Tunisian samples, the lowest scores were seen in Japanese, Saudi Arabian, Palestinian and Jordanian samples. Compared to participants with a suicidal past, those who were never suicidal displayed more internal barriers against suicidal behavior. Men were more accepting of suicide than women but women were more willing to help an imagined suicidal peer. Participants with accepting attitudes towards suicide but rejecting attitudes towards suicidal persons reported more suicidal behavior and psychological distress, and were more often from high suicide rate countries and samples than their counterparts. They are considered to be caught in a fatal trap in which most predominant feelings of suicidality such as hopelessness or helplessness are likely to occur. We conclude that in some societies such as Japan and Saudi Arabia it might be difficult for suicidal individuals to activate and make use of social support systems.     

Apparent movement in phenomenal space

The spatial and temporal variables in Korte’s third law of apparent movement were studied in pictorial arrays in which size constancy could be expected to prevail. The thresholds for apparent movement were determined under conditions in which two squares appeared on a plane either with or without perspective information for depth. The results suggest that apparent movement varies with the perceived depth separation only if the size of the stimulus pair is congruent with contextual depth representations. The obtained psychophysical function relating thresholds for third-dimensional movement to pictorial depth scale supports the view that apparent movement preserves gradient-of-texture information.