Systemic and intrahippocampal administrations of the glucocorticoid receptor antagonist RU38486 impairs fear memory reconsolidation in rats

Reconsolidation is the process by which previously consolidated memories are stabilized after retrieval. Several lines of evidence indicate that glucocorticoids modulate distinct phases of learning and memory. These effects are considered to be mediated by mineralocorticoid receptors and glucocorticoid receptors (GRs), which display a high concentration and distinct distribution in the hippocampus. The role of glucocorticoid system in fear memory reconsolidation is the subject of some controversy. Moreover, we found no studies that assessed the role of hippocampal GRs in fear memory reconsolidation. Here, we investigated the effect of GR blockade on fear memory reconsolidation in rats. Rats were trained and tested in an inhibitory avoidance task. Intrahippocampal or systemic administration of the GR antagonist RU38486 immediately following memory reactivation produced a deficit in post-retrieval long-term memory that persisted over test sessions, and memory did not re-emerge following a footshock reminder. These results indicate that hippocampal GRs are required for reconsolidation of fear-based memory.     

Zone of Proximal Development (ZPD) as an Emergent System: A Dynamic Systems Theory Perspective

This paper sets out to present a novel construal of one of the notions of Vygotskian cultural-historical theory viz., zone of proximal development (ZPD) drawing upon dynamic systems theory. The principal thesis maintains that ZDP is an emergent and dynamic system which is engendered by a dialectical concatenation of psychogenesic and sociogenesic facets of human development over time. It is reasoned that Vygotskian cultural-historical theory of human development, by invoking dialectical logic, has transcended Cartesian substance dualism and in turn has proffered a monistic and process-anchored ontology for emerging becoming of human consciousness. Likewise, it is contended that dynamic systems theory, having assumed fluent flux of reality with a capital R as its ontological axiom, entails a consilience of cognitive and contextual conceptual schemes to describe, explain, and optimize human development. The paper concludes by drawing some interpretive conclusions in regard to ZPD from dynamic systems theory perspective.     

Levels of Reading Comprehension Across Text Types: A Comparison of Literal and Inferential Comprehension of Expository and Narrative Texts in Iranian EFL Learners

The purpose of this study was to investigate two levels of reading comprehension, namely literal and inferential, of two text types of narration and exposition in Iranian EFL learners. The elicitation instruments were four expository texts and four narrative ones. One hundred eighty upper-intermediate EFL learners were assigned the reading passages followed by both literal and inferential multiple-choice items. Paired-samples t tests were run to provide answers to the research questions of this study. From an inter-text-type angle, the results demonstrated that the participants meaningfully outperformed on the expository texts at the level of literal comprehension. Yet, regarding inferential comprehension, there was no significant difference between the two text types. The results, from an intra-text-type perspective, also revealed that in the expository texts, literal comprehension meaningfully outweighed inferential comprehension, whereas no significant difference was observed between literal and inferential comprehension in the narrative texts. Finally, probable explanations and interpretations for the obtained results were provided.     

Fluctuations in Foreign Language Motivation: An Investigation into Iranian Learners’ Motivational Change over Time

English is broadly used as the language of politics, commerce, communication, internet, tourism, etc., which necessitates a multidimentional motivation to learn it. At the time, scholars claim that considering motivation as a Complex Dynamic System (CDS) is the best apparatus to tap this multidimensionality. The present study was an attempt to examine the interplay of different motivational factors influencing a group of Iranian participants’ decision to start and continue an English as a foreign language course. Eight participants were interviewed in the beginning, middle, and end of the semester to better picture the dynamic and complex nature of motivation. The results of the study lent support to the dynamicity of motivation. The findings also showed that several major motivational themes were at work and there were positively or negatively directed motivations. Finally, the implications of the study were discussed.     

Issues Involving Informed Consent for Research Participants with Alzheimer’s Disease

Alzheimer’s disease is the most common form of dementia which is estimated to impact 350,000 people over 65 years of age in Canada. The lack of effective treatment and the growing number of people who are expected to be diagnosed with Alzheimer’s disease in the near future are compelling reasons why continued research is in this area is necessary. With additional research, there needs to be greater recognition of the complexity of seeking ongoing informed consent from those with Alzheimer’s disease. This complexity is because the impairment of memory and cognitive ability does not diminish in a linear manner, but rather fluctuates between periods of impairment and relatively normal cognitive lucidness. There is limited discussion in the guidelines of those progressing from early stages of Alzheimer’s disease who have intermittent cognitive function. Guidelines to research and Research Ethics Boards require further development to facilitate researcher including those with Alzheimer’s disease while protecting this growing pool of potential participants.     

Voluntary exercise ameliorates cognitive deficits in morphine dependent rats: the role of hippocampal brain-derived neurotrophic factor

Chronic exposure to opiates impairs spatial learning and memory. Given the well-known beneficial effects of voluntary exercise on cognitive functions, we investigated whether voluntary exercise would ameliorate the cognitive deficits that are induced by morphine dependence. If an effect of exercise was observed, we aimed to investigate the possible role of hippocampal brain-derived neurotrophic factor (BDNF) in the exercise-induced enhancement of learning and memory in morphine-dependent rats. The rats were injected with bi-daily doses (10mg/kg, at 12h intervals) of morphine over a period of 10 days of voluntary exercise. Following these injections, a water maze task was performed twice a day for five consecutive days, followed by a probe trial 2 days later. A specific BDNF inhibitor (TrkB-IgG chimera) was used to block the hippocampal BDNF action during the 10 days of voluntary exercise. We found that voluntary exercise blocked the ability of chronic morphine to impair spatial memory retention. A blockade of the BDNF action blunted the exercise-induced improvement of spatial memory in the dependent rats. Moreover, the voluntary exercise diminished the severity of the rats' dependency on morphine. This study demonstrates that voluntary exercise ameliorates, via a TrkB-mediated mechanism, the cognitive deficits that are induced by chronic morphine. Thus, voluntary exercise might be a potential method to ameliorate some of the deleterious behavioral consequences of the abuse of morphine and other opiates.     

Development and Validation of Religious Sectarian Intolerance Scale for Muslim Adults in Pakistan

Journal of Religion and Health - Religious sectarian intolerance occurs when members of different religious sects within a faith are unable to tolerate the religious beliefs and practices of each...