Cholinergic activity in the insular cortex is necessary for acquisition and consolidation of contextual memory

Experiences with a high emotional content (aversive) tend to be stored as long-term memories; however, there are also contextual recollections, which form a significant part of our memories. Different research has shown that the insular cortex (IC) plays an important role during aversive memory formation, yet its role during incidental/non-aversive learning like pre-exposure contextual memory formation has received little attention. The objective of this research was to establish the role of cholinergic activity in the IC through its muscarinic receptors during the formation of inhibitory avoidance (IA) memory, as well as during pre-exposure contextual memory, using a paradigm such as latent inhibition (LI). Rats with bilateral cannulae directed into the IC were trained in the LI paradigm of IA or IA task alone. The muscarinic antagonist receptor scopolamine was infused bilaterally into the IC 5 min before the pre-exposure into the dark chamber of the IA cage, one day before the conventional IA training or during the IA training day. During the IA test, the entrance latency into the dark chamber of the IA cage was measured as an index of contextual memory. The results showed that scopolamine infused before and after IA training disrupts inhibitory avoidance memory. Also, it showed that the pre-exposed saline-infused animals (LI) had a lower entrance latency compared to the group not pre-exposed (IA). However, the group that received scopolamine into the IC before, but not after, the pre-exposure to the dark chamber, presented a similar latency to the IA group, showing a blockade of the latent inhibition of the IA. These results suggest that cholinergic activity in the insular cortex is necessary during the acquisition and consolidation of avoidance memory, but appears necessary only during the acquisition of pre-exposure non-aversive contextual memory.     

Electrical stimulation of the pedunculopontine tegmental nucleus in freely moving awake rats: time- and site-specific effects on two-way active avoidance conditioning

The pedunculopontine tegmental nucleus (PPTg) is involved in the regulation of thalamocortical transmission and of several functions related to ventral and dorsal striatal circuits. Stimulation of the PPTg in anesthetized animals increases cortical arousal, cortical acetylcholine release, bursting activity of mesopontine dopaminergic cells, and striatal dopamine release. It was hypothetized that PPTg stimulation could improve learning by enhancing cortical arousal and optimizing the activity of striatal circuits. We tested whether electrical stimulation (ES) of the PPTg, applied to freely-moving awake rats previously implanted with a chronic electrode, would improve the acquisition and/or the retention of two-way active avoidance conditioning, and whether this effect would depend on the specific PPTg region stimulated (anterior vs posterior) and on the time of ES: just before (pre-training) or after (post-training) each of three training sessions. The treatment consisted of 20 min of ES (0.2 ms pulses at 100 Hz; current intensity: 40-80 microA). The results showed that (1) this stimulation did not induce either any signs of distress nor abnormal behaviors, apart from some motor stereotyped behaviors that disappeared when current intensity was lowered; (2) pre-training ES applied to the anterior PPTg improved the acquisition of two-way active avoidance, (3) no learning improvement was found after either post-training ES of the anterior PPTg, or pre- and post-training ES of the posterior PPTg. The results give support to a role of PPTg in learning-related processes, and point to the existence of functional PPTg regions.     

mTOR signaling in the hippocampus is necessary for memory formation

It is widely accepted that the formation of long-term memory (LTM) requires mRNA translation, but little is known about the cellular mechanisms in the brain that regulate this process. Mammalian target of rapamycin (mTOR) is a key regulator of translational efficacy and capacity. Here, we show that LTM formation of one-trial inhibitory avoidance (IA) in rats, a hippocampus-dependent fear-motivated learning task, requires mTOR activation. IA training is specifically associated with a rapid increase in the phosphorylation state of mTOR and its substrate ribosomal S6 kinase (p70S6K). Bilateral intra-CA1 infusion of rapamycin, a selective mTOR inhibitor, 15 min before, but not immediately after training completely hinders IA LTM without affecting short-term memory (STM) retention. Therefore, our findings indicate that the regulation of hippocampal mRNA translation is a major control step in memory consolidation.     

Working models of attachment and reactions to different forms of caregiving from romantic partners

Inspired by attachment theory, the authors tested a series of theoretically derived predictions about connections between attachment working models (attachment to one's parents assessed by the Adult Attachment Interview; M. Main & R. Goldwyn, 1994) and the effectiveness of specific types of caregiving spontaneously displayed by dating partners during a stressful conflict-resolution discussion. Each partner first completed the Adult Attachment Interview. One week later, each couple was videotaped while they tried to resolve a current problem in their relationship. Trained observers then rated each interaction for the degree to which (a) emotional, instrumental, and physical caregiving behaviors were displayed; (b) care recipients appeared calmed by their partners' caregiving attempts; and (c) each partner appeared distressed during the discussion. Individuals who had more secure representations of their parents were rated as being more calmed if/when their partners provided greater emotional care, especially if they were rated as more distressed. Conversely, individuals who had more insecure (dismissive) representations of their parents reacted more favorably to instrumental caregiving behaviors from their partners, especially if they were more distressed. The broader theoretical implications of these findings are discussed.     

Resilient, undercontrolled, and overcontrolled personality prototypes among persons with spinal cord injury

A sample of 199 persons with spinal cord injury (SCI) were assessed on Big Five personality dimensions using the NEO Five-Factor Inventory (NEO-FFI; Costa & McCrae, 1992) at admission to an inpatient medical rehabilitation program. A cluster analysis of the baseline NEO-FFI yielded 3 cluster prototypes that resemble resilient, undercontrolled, and overcontrolled prototypes identified in many previous studies of children and adult community samples. Compared with normative samples, this sample had significantly fewer resilient prototypes and significantly more overcontrolled and undercontrolled prototypes. Undercontrolled individuals were the modal prototype. The resilient and undercontrolled types were better adjusted than the overcontrolled types, showing lower levels of depression at admission and higher acceptance of disability at discharge. The resilient type at admission predicted the most effective reports of social problem-solving abilities at discharge and the overcontrolled type the least. We discuss the implications of these results for assessment and interventions in rehabilitation settings.     

Temperamental dimension and anxiety problems in a clinical sample of three- to six-year old children: a study of variables

In the last few years, many researchers have studied the presence of common dimensions of temperament in subjects with symptoms of anxiety. The aim of this study is to examine the association between temperamental dimensions (high negative affect and activity level) and anxiety problems in clinical preschool children. A total of 38 children, ages 3 to 6 years, from the Infant and Adolescent Mental Health Center of Girona and the Center of Diagnosis and Early Attention of Sabadell and Olot were evaluated by parents and psychologists. Their parents completed several screening scales and, subsequently, clinical child psychopathology professionals carried out diagnostic interviews with children from the sample who presented signs of anxiety. Findings showed that children with high levels of negative affect and low activity level have pronounced symptoms of anxiety. However, children with anxiety disorders do not present different temperament styles from their peers without these pathologies.     

Assessing workplace bullying: Spanish validation of a reduced version of the Negative Acts Questionnaire

The aim of the present study was to validate a reduced Spanish version of the Negative Acts Questionnaire (NAQ; Einarsen & Raknes, 1997). This instrument, which has been widely used in various studies, was developed to measure workplace bullying. Two samples, the first comprising 352 employees from 11 organizations, and the second comprising victims of bullying who were recruited from 15 Spanish associations against bullying, participated in the study. Exploratory factor analysis conducted with the data from the first sample revealed a two-factor solution that accounted for 63.3% of the total variance. The data from the second sample were used for confirmatory factor analyses to compare three structure models of the NAQ (one factor, two independent factors, and two correlated factors). The results indicate that the correlated two-factor model provided the best fit to the data (chi2/df = 2.1, CFI = .93, GFI = .95, RMR = .04, RMSEA = .06, AIC = 215.4). Reliability analysis showed that this 14-item Spanish version had high internal consistency. Significant correlations between the NAQ and its dimensions and diverse health and perceived stress scales were found, which provided evidence of construct validity. Taken conjointly, the results of this study support the use of the Spanish version of the reduced NAQ in future research.     

Effects of prime task on affective priming by facial expressions of emotion

Priming of affective word evaluation by pictures of faces showing positive and negative emotional expressions was investigated in two experiments that used a double task procedure where participants were asked to respond to the prime or to the target on different trials. The experiments varied between-subjects the prime task assignment and the prime-target interval (SOA, stimulus onset asynchrony). Significant congruency effects (that is, faster word evaluation when prime and target had the same valence than when they were of opposite valence) were observed in both experiments. When the prime task oriented the subjects to an affectively irrelevant property of the faces (their gender), priming was observed at SOA 300 ms but not at SOA 1000 ms (Experiment 1). However, when the prime task assignment explicitly oriented the subjects to the valence of the face, priming was observed at both SOA durations (Experiment 2). These results show, first, that affective priming by pictures of facial emotion can be obtained even when the subject has an explicit goal to process a non-affective property of the prime. Second, sensitivity of the priming effect to SOA duration seems to depend on whether it is mediated by intentional or unintentional activation of the valence of the face prime.