On the role of hippocampal protein synthesis in the consolidation and reconsolidation of object recognition memory

Upon retrieval, consolidated memories are again rendered vulnerable to the action of metabolic blockers, notably protein synthesis inhibitors. This has led to the hypothesis that memories are reconsolidated at the time of retrieval, and that this depends on protein synthesis. Ample evidence indicates that the hippocampus plays a key role both in the consolidation and reconsolidation of different memories. Despite this fact, at present there are no studies about the consequences of hippocampal protein synthesis inhibition in the storage and post-retrieval persistence of object recognition memory. Here we report that infusion of the protein synthesis inhibitor anisomycin in the dorsal CA1 region immediately or 180 min but not 360 min after training impairs consolidation of long-term object recognition memory without affecting short-term memory, exploratory behavior, anxiety state, or hippocampal functionality. When given into CA1 after memory reactivation in the presence of familiar objects, ANI did not affect further retention. However, when administered into CA1 immediately after exposing animals to a novel and a familiar object, ANI impaired memory of both of them. The amnesic effect of ANI was long-lasting, did not happen after exposure to two novel objects, following exploration of the context alone, or in the absence of specific stimuli, suggesting that it was not reversible but was contingent on the reactivation of the consolidated trace in the presence of a salient, behaviorally relevant novel cue. Our results indicate that hippocampal protein synthesis is required during a limited post-training time window for consolidation of object recognition memory and show that the hippocampus is engaged during reconsolidation of this type of memory, maybe accruing new information into the original trace.     

Age-related changes and the attention network task: an examination of alerting, orienting, and executive function

The effects of aging on alerting, orienting, and executive function were examined with the use of the Attention Network Task, which combines the Posner spatial cuing task and the Eriksen flanker task into a single procedure. We found that older adults showed significantly less alerting than young adults in response to a warning cue, although there were no age differences in orienting or executive function once processing speed was taken into account. We suggest that age differences in alerting may depend in part upon the presentation duration or persistence of the warning cue.     

Measuring Lifestyle and Attachment: An Empirical Investigation Linking Individual Psychology and Attachment Theory

P. R. Peluso, J. P. Peluso, J. F. White, and R. M. Kern (2004) reviewed the theoretical constructs underlying the similarities between lifestyle and attachment style. Specifically, they suggested that the individual psychology construct of lifestyle (or style of life) and attachment style should be empirically investigated. The present research provided an empirical analysis of the concepts of lifestyle and attachment style and compared the methods for assessing these concepts. The findings supported the overall hypotheses that attachment style and lifestyle are similar constructs.     

Stress,Sex Differences,and Coping Strategies Among College Students

The sources of stress (academics, financial, family, social, and daily hassles) and coping strategies (self-help, approach, accommodation, avoidance, and self-punishment) of 166 college students were examined. The relationship between sex, specific sources of stress, and coping strategies was also investigated. Students completed a stress assessment inventory and a stress coping inventory based on a 5-factor revised COPE model (Zuckerman and Gagne Journal of Research in Personality, 37:169–204, 2003). Results found that college women reported a higher overall level of stress and greater use of emotion-focused coping strategies than college men. College men and women also reported different coping strategies for different stressors; however the use of emotion-focused coping strategies dominated over problem-solving strategies for both men and women. These results have implications for designing stress reduction workshops that build on the existing adaptive emotion-focused strategies of college students.     

Rates of Specific Antecedent Instructional Practices and Differences Between Title I and non-Title I Schools

The use of effective instructional strategies is clearly emphasized in current educational reform, especially in the area of reading. The purposes of this study were to investigate the rates at which specific instructional practices (i.e., attention signals, prior knowledge supports, previews, instructor modeling, student modeling, organizational prompts) were utilized during literacy time in elementary schools, determine if there were relationships among the instructional variables, and explore if teachers in Title I schools and teachers in non-Title I schools differed in their use of specific practices. Participants included teachers and students from 35 classrooms who were each observed for 5 hours, resulting in a total of 175 observation hours. The Setting Factors Assessment Tool (SFAT) was used to measure the antecedent instructional variables. Main results included that teachers in non-Title I classrooms used significantly more prior knowledge references than teachers in Title I schools; the effect size for this finding was large. Several correlations among the instructional variables were significant. The article concludes with a discussion of the main findings, implications for future research and the limitations of this study.     

Are head cues necessary for goats (Capra hircus) in recognising group members?

In this study, we investigated whether goats can distinguish a member of their own group from one belonging to a different group even when the head of the goat in question cannot be seen. In the experiment, a total of 45 adult female goats (walkers) were trained to walk along a passageway at the end of which they learnt to expect food (trial run). Walking down this corridor, they passed another adult female goat (stimulus goat) whose trunk and hind legs alone were visible. Using 19 individuals, ten pairs of stimulus goats consisting of one goat from the walker's group and one from a different group were matched in terms of body size, constitution, colour and coat length. In addition, the stimulus goat from the same group as the walker had to be higher ranking than the latter to avoid being attacked. The walkers completed two, four or six trial runs depending on the number of pairs suitable for a given walker. The walker's exploratory behaviour (observing and sniffing at the stimulus goat) was recorded. Data from 109 trial runs were analysed using generalised linear mixed-effects models with crossed random effects. On average, the walker spent a total of 8.7?s exploring the stimulus goat visually and olfactorily if the latter was from a different group and only about half as long (4.2?s) if it was from her own group. In particular, the time a walker spent observing a stimulus goat whilst approaching the latter was significantly longer if the stimulus goat belonged to a different group than to her own (2.5?s as opposed to 1.4?s). Moreover, a stimulus goat from a different group was sniffed at significantly longer (4.6?s) than one from the same group (1.9?s). Results suggest that goats can easily discriminate between members of their own group and those of a different group even when the latter's heads are hidden. Olfactory and visual cues are probably important for identifying group members.     

Intra-amygdala infusion of the protein kinase Mzeta inhibitor ZIP disrupts foreground context fear memory

Protein kinase Mzeta has been the subject of much recent interest, as it is the only molecule currently identified to maintain memory. Despite the wealth of studies investigating PKMζ in memory, questions remain about which types of memory PKMζ supports. Further, it is unclear how long the inhibitor of PKMz, ζ-pseudosubstrate inhibitory peptide (ZIP) remains in the brain after infusion. Here, we demonstrate that foreground context fear memory requires PKMζ activity in the amygdala. We also show that ZIP is fully cleared from the brain by 24h after infusion. These data contribute to a growing body of literature that demonstrates that PKMζ plays a key role in maintaining amygdala-dependent memory and provides new information about the degradation timecourse of the most commonly used inhibitor of PKMζ, ZIP.     

Trace and contextual fear conditioning are impaired following unilateral microinjection of muscimol in the ventral hippocampus or amygdala, but not the medial prefrontal cortex

Trace fear conditioning, in which a brief empty "trace interval" occurs between presentation of the CS and UCS, differs from standard delay conditioning in that contributions from both the hippocampus and prelimbic medial prefrontal cortex (PL mPFC) are required to form a normal long term memory. Little is currently known about how the PL interacts with various temporal lobe structures to support learning across this temporal gap between stimuli. We temporarily inactivated PL along with either ventral hippocampus or amygdala in a disconnection design to determine if these structures functionally interact to acquire trace fear conditioning. Disconnection (contralateral injections) of the PL with either the ventral hippocampus or amygdala impaired trace fear conditioning; however, ipsilateral control rats were also impaired. Follow-up experiments examined the effects of unilateral inactivation of the PL, ventral hippocampus, or amygdala during conditioning. The results of this study demonstrate that unilateral inactivation of the ventral hippocampus or amygdala impairs memory, while bilateral inactivation of the PL is required to produce a deficit. Memory deficits after unilateral inactivation of the ventral hippocampus or amygdala prevent us from determining whether the mPFC functionally interacts with the medial temporal lobe using a disconnection approach. Nonetheless, our findings suggest that the trace fear network is more integrated than previously thought.     

Repression and high anxiety are associated with aberrant diurnal cortisol rhythms in women with metastatic breast cancer.

Previous research has provided evidence of autonomic, endocrine, and immunological dysregulation in repressers and a possible association with cancer incidence and progression. Recently published data from the authors' laboratory demonstrated that flatter diurnal cortisol slopes were a risk factor for early mortality in women with metastatic breast cancer. In the current analysis of this same sample (N=91), the authors tested differences at baseline between groups scored using the Weinberger Adjustment Inventory on diurnal cortisol slope and mean cortisol levels. When compared with self-assured and nonextreme groups, the represser and high-anxious groups had a significantly flatter diurnal slope. Diurnal slope was similar for repressers and high-anxious groups. Groups did not differ on mean cortisol levels, nor did they differ on intercept (morning) values.