Identification of memory mechanism in tissue-resident stem cells via ANGPTL4 beyond immune cells upon viral antigen exposure

Although memory functions of immune cells characterized by increased resistance to subsequent infections after initial pathogen exposure are well-established, it remains unclear whether non-immune cells, especially tissue-resident stem cells, exhibit similar memory mechanisms. The present study revealed that detrimental effects of initial viral antigen exposure (human papillomavirus [HPV]) on diverse stem cell functions were significantly exacerbated upon subsequent secondary exposure both in vitro and in vivo. Importantly, endometrial stem cells exhibited robust memory functions following consecutive HPV antigen exposures, whereas fully differentiated cells such as fibroblasts and vesicular cells did not show corresponding changes in response to the same antigen exposures. Deficiency of angiopoietin-like 4 (ANGPTL4) achieved through small hairpin RNA knockdown in vitro and knockout (KO) mice in vivo highlighted the critical role of ANGPTL4 in governing memory functions associated with various stem cell processes. This regulation occurred through histone H3 methylation alterations and PI3K/Akt signaling pathways in response to successive HPV antigen exposures. Furthermore, memory functions associated with various stem cell functions that were evident in wild-type mice following consecutive exposures to HPV antigen were not observed in ANGPTL4 KO mice. In summary, our findings strongly support the presence of memory mechanism in non-immune cells, particularly tissue-resident stem cells.

A Cross-Cultural Study of Self-Defining Memories in Chinese and American College Students

Self-defining memories (SDMs) are touchstones in individuals’ narrative identity. This is the first SDM study to compare college students from the mainland People’s Republic of China (PRC) to American college students. It examined SDMs, Big Five personality traits, and memory function in 60 students from each country (n = 120). Participants rated their memories for affect, recall frequency, and importance. Chinese students recalled their most positively rated memories more frequently and with greater importance, while American students did not show this pattern. American students who scored higher in Openness were more likely to recall negative memories. Memory content coding revealed that Chinese students recalled significantly more guilt/shame events than American students. Further analysis indicated that these memories were particularly focused on academic performance and parental expectations. The discussion suggests that follow-up studies look at differing emotion regulation strategies in the two countries, as well as at how the two different educational systems are affecting late adolescent identity formation processes.

Atorvastatin has therapeutic potential for the fatty liver-induced memory dysfunction in rats, likely via its antioxidant and anti-inflammatory properties

This study aimed to evaluate the memory function in a rat model of fatty liver and to investigate the effects of statins on fatty liver, neuronal inflammation, oxidative stress and memory. In this study, 24 male rats were used and were divided into four groups consisting of 6 animals in each. Of them, 12 rats received liquid diet containing 35% fructose for 8 weeks in order to induce hepatosteatosis, while other animals had a normal nutrition. Group 1 served as controls and had a normal nutrition with no drug treatment. The animals in Group 2 had a normal nutrition and treated with atorvastatin. Group 3 received high-fructose diet with no drug treatment and Group 4 received high-fructose diet followed by atorvastatin treatment. After the two weeks of treatment period, passive avoidance tasks evaluating the memory were performed in both the study and control groups. The liver and brain were then removed for histologic, pathologic, and biochemical evaluation. In the non-treated rats with hepatosteatosis (Group 3), the lowest mean latency time and the highest mean histopathologic liver score, and brain TNF- α and MDA (Measurement of lipid peroxidation) were found (p < 0.00001). On the other hand, in the animals treated with atorvastatin, all these parameters were significantly higher than that of controls and significantly lower than that of Group 3 (p < 0.05). Fatty liver can increase inflammation and cause memory disorders, and atorvastatin may have a positive effect on cognitive disorders.

Use, Adaptivity, and Need Fulfillment: A Methodological Critique of Tests of the Functions of Autobiographical Memory

In this article, we champion the study of autobiographical memory functions. We review the proposed functions and how they have been investigated. We describe seven commonly used research designs. We argue that although each design offers unique benefits, none of these designs is ideally suited to test the functional nature of autobiographical memory with high internal validity. We stress that each design does have a unique set of benefits in the exploration of autobiographical memory and none should be abandoned. However, we encourage researchers interested in function in particular to consider designs that will illuminate the use, adaptivity, and fulfillment of needs that is inherent in the definition of function.

The relationship between the Wechsler Memory Scale-Revised scores and whole-brain structure in patients with schizophrenia and healthy individuals

INTRODUCTION

The Wechsler Memory Scale (WMS) is a standardised battery for assessing memory functions. We aimed to investigate the relationship between all WMS scores, including subtests, and whole-brain structure in a relatively large sample.

METHODS

Participants were 93 patients with schizophrenia and 117 healthy individuals, all right-handed and of Japanese ethnicity, and matched for age and sex. Their memory functions were assessed using the WMS-Revised (WMS-R). Their grey and white matter structure was analyzed using voxel-based morphometry and diffusion tensor imaging.

RESULTS

Verbal memory score correlated positively with volumes of the left parahippocampal gyrus and hippocampus, while general memory score correlated positively with volumes of the left parahippocampal and fusiform gyri and hippocampus (p < 0.05, corrected), while there was no correlation with white matter fractional anisotropy values in healthy individuals. No correlation was observed between any WMS-R score and grey or white matter structure in patients.

CONCLUSIONS

Using whole-brain structural magnetic resonance imaging, we found several significant correlations between WMS-R scores and grey matter volume in the brains of healthy individuals, while no correlation was found in those of patients with schizophrenia.

Cognitive impairment and cortisol levels in first-episode schizophrenia patients

Many modalities of cognition are affected in schizophrenia. The most common findings include dysfunctions of episodic and working memory and of executive functions. Although an inverse correlation between cortisol level and memory function has been proven, few studies have focused on the relationship between cortisol level and cognitive impairment in patients with schizophrenia. In an open, naturalistic, prospective study, consecutively hospitalized males diagnosed with first-episode schizophrenia, hypothalamic-pituitary-adrenal axis activity (afternoon cortisol levels, post-dexamethasone cortisol levels) was evaluated before and at the end of acute treatment. Psychopathology was assessed using the positive and negative syndrome scale (PANSS). Cognitive functions (memory, attention, psychomotor, verbal fluency, and executive functions) were tested after symptom alleviation using a neurocognitive test battery. In the total sample (n = 23), significant decreases in total PANSS score (including all subscales), afternoon cortisol levels, and post-dexamethasone cortisol levels occurred during the course of treatment. It was found that higher afternoon cortisol levels at the beginning of treatment were significantly related to impaired performance in memory functions. Afternoon cortisol levels were not significantly associated with other measured cognitive functions. No correlation was discovered between cognitive functions and post-dexamethasone cortisol levels. The determination of afternoon cortisol levels may serve to detect potential candidates for specific cognitive intervention immediately after the first psychotic breakthrough.

Soybean-derived phosphatidylserine improves memory function of the elderly Japanese subjects with memory complaints

Soybean-derived phosphatidylserine (Soy-PS) is a phosphatidylserine made from soybean lecithin by enzymatic reaction with L-serine. A double-blind, randomized controlled study was conducted to investigate the effects of Soy-PS on the cognitive functions of the elderly Japanese subjects with memory complaints. Seventy-eight elderly people with mild cognitive impairment (50–69 years old) were randomly allocated to take Soy-PS (100 mg, 300 mg/day) or placebo for 6 months. As a result, there was no difference in blood markers and vital signs during Soy-PS treatment and any side effect caused by Soy-PS treatment was not observed. Neuropsychological test scores were similarly increased in all groups including placebo group. However, in the subjects with relatively low score at baseline, the memory scores in PS treated groups were significantly increased against the baseline, while those of placebo group remained unchanged. And the memory improvements in Soy-PS-treated groups were mostly attributed to the increase in delayed verbal recall, a memory ability attenuated in the earliest stage of dementia. In conclusion, Soy-PS used in this study is considered as safety food ingredient and 6 months of Soy-PS supplementation could improve the memory functions of the elderly with memory complaints.