Autophosphorylation of alphaCaMKII is differentially involved in new learning and unlearning mechanisms of memory extinction

Accumulating evidence indicates the key role of alpha-calcium/calmodulin-dependent protein kinase II (alphaCaMKII) in synaptic plasticity and learning, but it remains unclear how this kinase participates in the processing of memory extinction. Here, we investigated the mechanism by which alphaCaMKII may mediate extinction by using heterozygous knock-in mice with a targeted T286A mutation that prevents the autophosphorylation of this kinase (alphaCaMKII(T286A+/-)). Remarkably, partial reduction of alphaCaMKII function due to the T286A(+/-) mutation prevented the development of extinction without interfering with initial hippocampus-dependent memory formation as assessed by contextual fear conditioning and the Morris water maze. It is hypothesized that the mechanism of extinction may differ depending on the interval at which extinction training is started, being more akin to "new learning" at longer intervals and "unlearning" or "erasure" at shorter intervals. Consistent with this hypothesis, we found that extinction conducted 24 h, but not 15 min, after contextual fear training showed spontaneous recovery (reappearance of extinguished freezing responses) 21 d following the extinction, representing behavioral evidence for new learning and unlearning mechanisms underlying extinction 24 h and 15 min post-training, respectively. Importantly, the alphaCaMKII(T286A+/-) mutation blocked new learning of contextual fear memory extinction, whereas it did not interfere with unlearning processes. Our results demonstrate a genetic dissociation of new learning and unlearning mechanisms of extinction, and suggest that alphaCaMKII is responsible for extinguishing memories specifically through new learning mechanisms.     

Differential effects of beta-adrenergic receptor blockade in basolateral amygdala or insular cortex on incidental and associative taste learning

The importance of central β-adrenergic system has been essentially investigated in aversive/emotional learning tasks. However, recent data suggest that the β-adrenergic system is also required for incidental taste learning. In the present study we evaluated in rats whether β-adrenergic receptor activity is required for taste habituation, an incidental taste learning, and also for conditioned taste aversion (CTA) learning, an associative learning. To address this issue, a low dose of the β-adrenergic antagonist propranolol was infused before learning in either the basolateral amygdala (BLA) or the insular cortex (IC), two forebrain areas reported to play a key role in taste memory formation. Incidental taste learning was assessed using a single presentation of the sweet taste saccharin 0.1%, which is sufficient to increase saccharin consumption (relative to water baseline) during a second presentation. CTA was assessed by pairing the first saccharin 0.1% presentation with a delayed gastric malaise, thus causing a decrease in saccharin consumption (relative to water baseline) during a second presentation. Propranolol infusion in BLA (1 μg/0.2μl) or IC (2.5 μg/0.5 μl) before the first taste exposure impaired incidental taste learning but did not affect CTA. These results highlight the important role played by the β-adrenergic receptor activation in cortical and amygdaloid structures during taste learning. Moreover, they are the first to suggest that incidental learning is more sensitive to blockade of noradrenergic system than associative learning.     

Systemic administration of a nitric oxide synthase inhibitor impairs fear sensitization in the plus-maze

The aim of the present study was to evaluate the occurrence of fear sensitization in rats previously treated with an inhibitor of the NO syntheses and submitted to Trial1/Trial2 plus-maze (PM) procedure. Male Wistar rats received a systemic treatment with N(omega)-nitro-L-Arginine-methyl ester (L-NAME; 5, 10 or 50 mg kg(-1)) and were submitted to PM Trial1. In the following day the animals were re-exposed to the PM with no drug administration (Trial2). Some standards spatial-temporal measures, such as the percentage of entries (% Open arm entries) and time spent (% Open arm time) in the open arms and risk assessment frequency were recorded and used to estimate the animal level of fear sensitization in PM Trial2. The results showed that animals receiving L-NAME (50 mg kg(-1)) displayed increased % Open arm entries and % Open arm time in Trial2 in relation to the group receiving 0.9% saline, which is compatible with impaired fear/anxiety acquisition during Trial1/Trial2 PM procedure. In addition, rats treated with L-NAME (50 mg kg(-1)) exhibited low level of risk assessment in Trial2 in relation to the group treated with 0.9% saline, which indicates low level of fear/anxiety during PM re-exposure. The number of entries into the enclosed arms was not changed by any L-NAME treatment, which suggests no bias of the drug treatments on animal locomotor activity. The data suggest that NO synthesis may mediate the fear sensitization process in the PM.     

CONCURRENT RESURGENCE AND BEHAVIORAL HISTORY

The contribution of past experiences to concurrent resurgence was investigated in three experiments. In Experiment 1, resurgence was related to the length of reinforcement history as well as the reinforcement schedule that previously maintained responding. Specifically, more resurgence occurred when key pecks had been reinforced on a variable-interval 1-min schedule than a variable-interval 6-min schedule, but this effect may have been due either to the differential reinforcement rates or differential response rates under the two schedules. When reinforcement rates were similar (Experiment 2), there was more resurgence of high-rate than low-rate responding. When response rates were similar (Experiment 3), resurgence was not related systematically to prior reinforcement rates. Taken together, these three experimental tests of concurrent resurgence illustrate that prior response rates are better predictors of resurgence than are prior reinforcement rates.     

The Quality of Home Environment in Brazil: An Ecological Model

Based on Bronfenbrenner's (1999) ecological perspective, a longitudinal, prospective model of individual differences in the quality of home environment (Home Observation for Measurement of the Environment—HOME) was tested in a sample of 179 Brazilian children and their families. Perinatal measures of family socioeconomic status (SES) and child birth weight had direct effects on HOME at preschool age. As either family SES or child birth weight increased, HOME also increased through diminished emotional distress in the mother a month following childbirth. SES had a negative effect on number of children in the household, which in turn had a long-term negative impact on HOME. Compared to mothers who had reported not to plan their pregnancy, those who did were more likely to have fewer children, to report more spouse support during childbearing, and to show less emotional distress a month after childbirth, all of which also influenced HOME at preschool age. These findings are discussed in light of the broader socio-ecological Brazilian context, with direct implications to clinical practice aimed at improving the quality of home environment.     

Validation of a Portuguese version of the multidimensional measure of employability

This study describes the validity and reliability evidence of the multidimensional measure of employability (MME) based on the internal structure and relations to career self-efficacy and career success. Two hundred forty seven Portuguese persons (75.7% women) aged from 21–73 years old (M = 39.9, SD = 10.9) participated. Confirmatory factor analysis suggested adequate fit in the correlational and hierarchical models. Measurement reliability was good for total score and each factor. Correlations with the additional measures provided evidence of validity. MME provides a tool for research and career counseling, enabling comprehensive employability assessment and personalized interventions, while recognising the interplay between employability dimensions.     

Psychometric properties of the Spanish version of the Revised Competitive State Anxiety Inventory-2 with athletes

The aim of this work was to develop a Spanish adaptation of the Revised Competitive State Anxiety Inventory-2. The scale was translated and its psychometric properties were analyzed with data from a sample of 149 athletes. Exploratory and confirmatory factor analyses were performed which supported a 16-item CSAI-2R assessing the three hypothesised dimensions of anxiety: Somatic anxiety, Cognitive anxiety, and Self-confidence. Overall fit of the model was good with a value of .97 for Comparative and Non-Normed Fit Indexes, and .045 for Root Mean Square Error of Approximation. Cronbach alpha coefficients for the factors ranged from .79 to .83. It is concluded that this version shows adequate properties, in terms of its dimensionality and internal consistency. Guidelines are also provided for future research on its validity as a measure of state anxiety in competitive situations.     

Maintained attitudinal changes in nursing personnel after a brief training on suicide prevention

Nursing personnel (N = 317) working at a general hospital attended a 6-hour training program on suicide prevention. They answered anonymously pre- and post-training the Suicide Behavior Attitude Questionnaire (SBAQ), which comprises 21 visual analogue scale items divided in three factorial subscales. The results indicated there were positive changes in the attitudes and these gains were significantly maintained at the 6-month follow-up evaluation. Improvement was in the Feelings and Professional Capacity subscales (ANOVA; p = 0.0001 and 0.01, respectively). There was no change on the Right to Suicide subscale. Because attitudes influence the effectiveness of health care personnel interventions, our findings may have important implications for the development of suicide prevention programs.     

Neural events in the reinforcement contingency

When neural events are analyzed as stimuli and responses, functional relations among them and among overt stimuli and responses can be unveiled. The integration of neuroscience and the experimental analysis of behavior is beginning to provide empirical evidence of involvement of neural events in the three-term contingency relating discriminative stimuli, responses, and consequences. This paper is aimed at highlighting exemplar instances in the development of this issue. It has long been known that the electrical stimulation of certain cerebral areas can have a reinforcing function. Extraordinary technological advances in recent years show that neural activity can be selected by consequences. For example, the activity of in vitro isolated neurons that receive dopamine as a reinforcer functions as a cellular analogue of operant conditioning. The in vivo activity of populations of neurons of rats and monkeys can be recorded on an instant-to-instant basis and can then be used to move mechanical arms or track a target as a function of consequences. Neural stimulation acts as a discriminative stimulus for operant responses that are in turn maintained by neural consequences. Together with investigations on the molecular basis of classical conditioning, those studies are examples of possibilities that are being created for the study of behavior-environment interactions within the organism. More important, they show that, as an element in the three-term contingency, neural activity follows the same laws as other events.     

How is the boss's mood today? I want a raise

Other people's incidental feelings can influence one's decision in a strategic manner. In a sequential game in which proposers moved first by dividing a given pot of cash (keeping 50% or 75% of the pot) and receivers responded by choosing the size of the pot (from 0 dollars to 1 dollar), proposers were more likely to make an unfair offer (i.e., to keep 75% of the pot) if they were told that receivers had watched a funny sitcom, rather than a movie clip portraying anger, in an unrelated study prior to the game playing. However, when proposers were told that receivers knew proposers had this affective information, the effect dissipated. In other words, a proposer expects a happy receiver to be more accommodating or cooperative than an angry receiver as long as the happy receiver does not realize that the proposer may be trying to benefit from the receiver's current incidental feelings.