A Role for Dendritic Translation of CaMKIIα mRNA in Olfactory Plasticity

Local protein synthesis in dendrites contributes to the synaptic modifications underlying learning and memory. The mRNA encoding the α subunit of the calcium/calmodulin dependent Kinase II (CaMKIIα) is dendritically localized and locally translated. A role for CaMKIIα local translation in hippocampus-dependent memory has been demonstrated in mice with disrupted CaMKIIα dendritic translation, through deletion of CaMKIIα 3′UTR. We studied the dendritic localization and local translation of CaMKIIα in the mouse olfactory bulb (OB), the first relay of the olfactory pathway, which exhibits a high level of plasticity in response to olfactory experience. CaMKIIα is expressed by granule cells (GCs) of the OB. Through in situ hybridization and synaptosome preparation, we show that CaMKIIα mRNA is transported in GC dendrites, synaptically localized and might be locally translated at GC synapses. Increases in the synaptic localization of CaMKIIα mRNA and protein in response to brief exposure to new odors demonstrate that they are activity-dependent processes. The activity-induced dendritic transport of CaMKIIα mRNA can be inhibited by an NMDA receptor antagonist and mimicked by an NMDA receptor agonist. Finally, in mice devoid of CaMKIIα 3′UTR, the dendritic localization of CaMKIIα mRNA is disrupted in the OB and olfactory associative learning is severely impaired. Our studies thus reveal a new functional modality for CaMKIIα local translation, as an essential determinant of olfactory plasticity

To Examine the Effects of Exercise & Instructional Based Interventions on Executive Functioning, Motor Learning & Emotional Intelligence Abilities Among Older Adults

Motor skills are a vital part of our life, and there might be situations where we will be required to either learn a new skill or relearn a known one. We examined the effectiveness of two different interventions - eccentric exercise and motivation-based instructions on enhancing the ability of older adults to learn a novel motor skill. Exercise intervention studies have shown that as little as 12 weeks of exercise can lead to improvements in both physical fitness and cognitive function in older adults, particularly executive control. But it is still unclear whether those improvements translate to improvements in other domains that rely on executive control, like motor skill learning and emotional intelligence. Study 1 explored the effect of eccentric exercise on these domains, specifically the ability to handle proactive interference in motor learning. 22 healthy adults (65-85 years of age) were recruited and randomly assigned either to a non-exercise control group, or to an exercise intervention group that performed 12 weeks of low to moderate intensity eccentric leg exercise (Eccentron). Corresponding neurophysiological measures were also recorded using EEG. We found that the control group experienced more proactive interference from baseline learning to post-test compared to the exercise group. The latter also displayed a higher level of emotional processing abilities than controls. They provide preliminary evidence that the cognitive benefits of exercise for older adults can be extended to domains outside of but related to executive control and memory. In study 2, we examined the effectiveness of an intervention based on the OPTIMAL theory of motor learning and performance on skill acquisition in both younger and older adults. We recruited 39 younger adults and 30 older adults and randomly assigned them to either the experimental group or to the control group. The intervention affected the two groups differentially. It was somewhat successful at improving learning in the older adults, but not in the younger adults. In fact, the intervention may have interfered with learning in the latter

Proceedings of the ECCS 2005 satellite workshop: embracing complexity in design - Paris 17 November 2005

Embracing complexity in design is one of the critical issues and challenges of the 21st century. As the realization grows that design activities and artefacts display properties associated with complex adaptive systems, so grows the need to use complexity concepts and methods to understand these properties and inform the design of better artifacts. It is a great challenge because complexity science represents an epistemological and methodological swift that promises a holistic approach in the understanding and operational support of design. But design is also a major contributor in complexity research. Design science is concerned with problems that are fundamental in the sciences in general and complexity sciences in particular. For instance, design has been perceived and studied as a ubiquitous activity inherent in every human activity, as the art of generating hypotheses, as a type of experiment, or as a creative co-evolutionary process. Design science and its established approaches and practices can be a great source for advancement and innovation in complexity science. These proceedings are the result of a workshop organized as part of the activities of a UK government AHRB/EPSRC funded research cluster called Embracing Complexity in Design (www.complexityanddesign.net) and the European Conference in Complex Systems (complexsystems.lri.fr). Embracing complexity in design is one of the critical issues and challenges of the 21st century. As the realization grows that design activities and artefacts display properties associated with complex adaptive systems, so grows the need to use complexity concepts and methods to understand these properties and inform the design of better artifacts. It is a great challenge because complexity science represents an epistemological and methodological swift that promises a holistic approach in the understanding and operational support of design. But design is also a major contributor in complexity research. Design science is concerned with problems that are fundamental in the sciences in general and complexity sciences in particular. For instance, design has been perceived and studied as a ubiquitous activity inherent in every human activity, as the art of generating hypotheses, as a type of experiment, or as a creative co-evolutionary process. Design science and its established approaches and practices can be a great source for advancement and innovation in complexity science. These proceedings are the result of a workshop organized as part of the activities of a UK government AHRB/EPSRC funded research cluster called Embracing Complexity in Design (www.complexityanddesign.net) and the European Conference in Complex Systems (complexsystems.lri.fr)

Communications and control for electric power systems: Power system stability applications of artificial neural networks

This report investigates the application of artificial neural networks to the problem of power system stability. The field of artificial intelligence, expert systems, and neural networks is reviewed. Power system operation is discussed with emphasis on stability considerations. Real-time system control has only recently been considered as applicable to stability, using conventional control methods. The report considers the use of artificial neural networks to improve the stability of the power system. The networks are considered as adjuncts and as replacements for existing controllers. The optimal kind of network to use as an adjunct to a generator exciter is discussed

Training older adults: the role of strategy use and stereotype threat

2011 Fall.Includes bibliographical references.Older adults are becoming an increasingly important part of the workforce. Due to cognitive and emotional changes associated with aging, this population might require specially designed training programs to optimize training outcomes. Two specific changes associated with aging that need to be addressed are susceptibility to stereotype threat and the use of metacognitive strategies during learning. The purpose of this study was to investigate the effect of initiating stereotype threat in older adults, as well as the effect of encouraging older adults to use metacognitive strategies during training, on training outcomes. In a 2X2 between-subject experimental design including no stereotype threat/ stereotype threat and no metacognitive prompt/ metacognitive prompt conditions, 131 older adults between the ages of 55 and 70 years old were assessed on training outcomes. Results indicated that, as hypothesized, stereotype threat had a negative effect on learning outcomes. Contrary to expectations, cognitive prompts also had a negative effect on training outcomes. Implications of the results are that further investigation of optimal training design for older adults is warranted

Mental practice and motor learning

This thesis is an investigation into the phenomena of mental practice, that is the thinking through of a movement, or movement sequences prior to actual performance. Using a gross motor skill it was demonstrated that it is the sequential, or cognitive component of the task that is most affected by mental practice, rather than the execution of the movements themselves. As a result of enhanced sequence learning overall performance does improve. Further experiments revealed that individuals can produce . novel movement sequences without prior physical practice of the task. Subjects demonstrated the ability to produce such sequences as long as they have information about the order and types of movements to be performed. Finally, an attempt was made to characterise the individual differences that might be associated with the capacity to use mental practice effectively. The literature on mental practice reveals that imagery may be a factor within this context. A test of imagery was designed, and its validity and reliability established. This test was used to screen subjects prior to participation in a mental practice study. Unfortunately, no significant relationship was found between imagery, as measured by the test, and improved performance on the task. There was however, a correlation between test scores and the rate of initial learning. The experimental results are discussed in terms of two proposals. The first is the relationship between mental practice and symbolic learning theory. The second is the possible role of such practice in the preparation of motor programs prior to performance

A study of the self-assembly of water-soluble porphyrins in aqueous solution

In nature, self-assembly processes of biologically active organic molecules often occur, resulting in formation of dimers and higher oligomers of various and sometimes complex structures. This natural occurrence of self-organization has been the subject of research, with the aim of understanding and possibly modulating the aggregation behavior of biological molecules. The meso-tetrakis(4-phosphonatophenyl) porphyrin, H2TPPP was synthesized, purified, and characterized. Its self-assembly was studied in aqueous solutions as a function of pH and time. The variations on the λmax and shape of the Soret band of this porphyrin in the absorption spectra when altering the pH indicated the pH dependency in the hierarchical self-assembly of H2TPPP in aqueous solution. The aggregation as a function of time was monitored via fluorescence spectroscopy, where the emission intensity decrease suggests self-quenching and aggregation. Small angle x-ray scattering experiments were conducted in an attempt to obtain structural information for the self-organized porphyrin complexes. Analytical ultracentrifugation techniques confirmed reported SAXS results and also revealed the self-associative behavior of the aggregates

Doctor of Philosophy

dissertationPrior evidence from several research areas suggests that performance improvements can accrue during intervals that preclude further practice of a procedural skill; however, the mechanism underlying this improvement is unclear. In order to test competing explanations for such improvement, the author investigated the effects of varying the cognitive demands of a secondary task interpolated into a course of cognitive skill practice. The moderately complex skill task that was used presented electrical circuitry operations (logic gates) and their corresponding rules, which participants learned first through declarative instruction and thereafter through multiple blocks of procedural practice. The interpolated task was either a cognitively demanding working memory (WM) test or a noncognitively demanding period spent listening to binaural alpha-wave beats over headphones. Three theory-based explanations for skill improvement during the interpolated task, or gap facilitation, were tested: memory consolidation, release from proactive interference (PI), and mental rest. Each explanation makes unique predictions regarding parameters of a power function used to describe the trajectory of each participant's skill performance before and after the interpolated tasks. Evidence favored release from PI as being responsible for the observed gap facilitation effects. Findings are interpreted with respect to learning theory that predicts performance decline with time away from practice and in light of prior explanations of evidence to the contrary