Stability of recent and remote contextual fear memory

Following initial encoding, memories undergo a prolonged period of reorganization. While such reorganization may occur in many different memory systems, its purpose is not clear. Previously, we have shown that recall of recent contextual fear memories engages the dorsal hippocampus (dHPC). In contrast, recall of remote contextual fear memories engages a number of different cortical regions, including the anterior cingulate cortex (ACC). To examine whether this reorganization leads to greater memory stability, we examined reconsolidation of 1 d-old (recent) and 36 d-old (remote) contextual fear memory in mice. We infused the protein synthesis inhibitor, anisomycin (ANI), into either the dHPC or ACC immediately following retrieval of either a recent or remote contextual fear memory. In the dHPC, ANI infusions disrupted subsequent expression of recent, but not remote, contextual fear memory. Similar infusions into the ACC had no effect on either recent or remote contextual fear memories, whereas systemically applied ANI blocked subsequent remote memory expression when long re-exposure durations were used. Together, these data suggest that as memories mature they become increasingly stable. Furthermore, the dissociation between the effects of systemically and centrally administered ANI on remote memory suggests that stability is due, in part, to the distributed nature of remote contextual fear memories.     

One percent ability and ninety-nine percent perspiration: a study of a Japanese memorist

In 1987, Hideaki Tomoyori, a Japanese memorist, set a world record for reciting the first 40,000 digits of pi. The authors report results from a series of tests that give a view of Tomoyori's memory performance compared with that of a control group, matched for age and educational level. He showed very good scores on tasks with digits, such as digit memory span tasks and 5 x 5 number matrix learning, although some of the control participants were nearly as good. In contrast, his performance was not particularly good for learning word lists and story recall. Overall, his performance on the tasks does not suggest that he has superior cognitive abilities. We believe that his extraordinary memory performance in reciting the digits of pi results from his effective use of a combination of digit-syllable transformations and imagery mnemonics developed from extensive practice. These results are consistent with the skilled memory framework.     

Stigma and Mental Health in Japanese Unemployed Individuals

An Internet‐based survey was administered in Japan to compare mental health of and stigma toward unemployed individuals, workers with regular employment, and workers with irregular employment. Unemployed individuals showed higher scores for both anxiety/depression and disturbance of activities, as well as faced more stigma than did employed individuals. In addition, the factor structure of stigma that unemployed individuals have toward the unemployed was the same as that previously found for university students and employed individuals. Financial strain and stigma were the factors with the greatest influence on the mental health of unemployed individuals.     

The role of the nucleus accumbens in knowing when to respond

While knowing what to expect is important, it is equally important to know when to expect it and to respond accordingly. This is apparent even in simple Pavlovian training situations in which animals learn to respond more strongly closer to reward delivery. Here we report that the nucleus accumbens core, an area well-positioned to represent information about the timing of impending rewards, plays a critical role in this timing function.     

Illusory motion induced by blurred red-blue edges

Visual patterns consisting of a red-and-blue region with a blurry edge yield illusory motion. Eye movements over a static pattern induced illusory motion of the edge in the direction opposite to the eye movement. The illusion also takes place for patterns in motion without eye movement. The illusion suggests the effect of colour combination on the spatial perception of a blurry edge.     

Perceptions of the Concept of Mutation among Family Members of Patients Receiving Outpatient Genetic Services and University Students

Our objectives were to investigate: (1) relationships between perceptions of various terms regarding mutation and the depth of knowledge regarding mutation among family members of patients receiving genetic outpatient services, and (2) differences in perceptions of the term “gene mutation” for family members versus university students. Fifty-eight family members and 178 university students responded to two questionnaires: Impressions regarding the term, and Knowledge about the concept of mutation. Factor analyses were conducted to determine the factor structure of ratings of the terms, and two-way analyses of variance [(1)Term, (2)Group × Knowledge] were conducted to examine differences in perceptions of the terms as measured by scores for each extracted factor. Family members had a significantly more negative perception of the term “gene mutation” than “gene change” and a less negative perception of the term “gene mutation” than “gene lesion”; they had significantly more negative perceptions of the term “gene mutation” than did university students.     

Widowhood and illness: a comparison of social network characteristics in France, Germany, Japan, and the United States.

This study examined social network characteristics of adults aged 70 to 90 years in relation to widowhood and illness in France, Germany, Japan, and the United States. Participants were drawn from representative samples from each of the 4 countries (total N = 1,331). Resource deficit profiles based on whether respondents were widowed, ill, both, or neither were directly related to social network characteristics for German and Japanese adults, were differentially related by gender and age for French adults, and were not related to social networks of Americans. Country, gender, and age differences in total network size, proportion of close network members, and frequency of contact with network members are reported. Similarities and differences found in the associations between normative late-life deficits and social network characteristics in the 4 countries point to the importance of investigating sociocultural factors that mediate the impact of resource loss and afford life quality in very old age.     

Effectiveness of color in picture recognition memory

Investigations were conducted into the effectiveness of color in picture recognition memory. In the study phase, half of the pictures were presented in color and the other half in black and white. In the test phase, half were presented in the same color mode as the study pictures and the other half in the other mode. In immediate and 1-week-delayed tests, the recognition performance was highest when color pictures were used in both the study and test phases. The recall for the color mode of the study pictures, however, was not as good, even with the color pictures. This suggests that the effectiveness of color in picture recognition is not necessarily due to the memory for colors in the pictures themselves, but is probably due to the distinctiveness of features highlighted by the colors. We also found that in the recall performance for the color mode it was more difficult to detect the deletion of colors than to detect their addition.     

Intrasexual interactions among female golden hamsters (Mesocricetus auratus) over the estrous cycle

Social interactions of cycling female golden hamsters paired with ovariectomized animals in large enclosures were primarily agonistic over the 4-day estrous cycle. These aggressive interactions were intense as indicated by frequent occurrences of chase and flight behavior. Dominant and subordinate social ranks were established in the majority of pairs (96%) tested, and even females in sexual heat were capable of attacking and dominating their rivals. Furthermore, cycling females exhibited significantly more aggressive acts than ovariectomized opponents 1 day prior to sexual receptivity. No differences in fighting patterns were found between animals on the other 3 days of the estrous cycle. Additional analyses revealed clear differences in agonistic elements, including flank marking, between dominant and subordinate females regardless of whether they were gonadectomized or intact. These analyses also showed that dominant individuals frequently chased and bit opponents during encounters within their nesting area. The data are examined for implications on the adaptive organization of female hamster agonistic behavior and the neuroendocrine regulation of species-typical behavior over the estrous cycle.     

The central amygdala nucleus via corticotropin-releasing factor is necessary for time-limited consolidation processing but not storage of contextual fear memory

The central nucleus of the amygdala (CeA) is traditionally portrayed in fear conditioning as the key neural output that relays conditioned information established in the basolateral amygdala complex to extra-amygdalar brain structures that generate emotional responses. However, several recent studies have questioned this serial processing view of the amygdalar fear conditioning circuit by showing an influence of the CeA on memory consolidation. We previously reported that inhibition of endogenous CeA secretion of corticotropin-releasing factor (CRF) at the time of contextual training effectively impaired fear memory consolidation. However, the time-dependent range of CeA CRF secretion in facilitating consolidation processing has not been examined. Therefore, to address this issue, we performed CeA site-specific microinjections of CRF antisense oligonucleotides (CRF ASO) at several post-training time intervals. Rats microinjected with CRF ASO at post-training intervals up to 24-h subsequently exhibited significant impairments in contextual freezing retention in contrast to animals treated 96-h after training. To further establish the validity of the results, CeA fiber-sparing lesions were made at two distinct post-training periods (24-h and 96-h), corresponding respectively to the temporal intervals when CeA CRF ASO administration disrupted or had no significant effects on memory consolidation. Similar to the CeA CRF ASO results, CeA lesions made 24-h, but not 96-h, after training induced significant freezing deficits in the retention test. In conclusion, the current results demonstrate: (1) an extended involvement of CeA CRF in contextual memory consolidation and (2) that contextual fear memory storage is not dependent on a functional CeA.