Learning to Learn: Theta Oscillations Predict New Learning, which Enhances Related Learning and Neurogenesis

Animals in the natural world continuously encounter learning experiences of varying degrees of novelty. New neurons in the hippocampus are especially responsive to learning associations between novel events and more cells survive if a novel and challenging task is learned. One might wonder whether new neurons would be rescued from death upon each new learning experience or whether there is an internal control system that limits the number of cells that are retained as a function of learning. In this experiment, it was hypothesized that learning a task that was similar in content to one already learned previously would not increase cell survival. We further hypothesized that in situations in which the cells are rescued hippocampal theta oscillations (3–12 Hz) would be involved and perhaps necessary for increasing cell survival. Both hypotheses were disproved. Adult male Sprague-Dawley rats were trained on two similar hippocampus-dependent tasks, trace and very-long delay eyeblink conditioning, while recording hippocampal local-field potentials. Cells that were generated after training on the first task were labeled with bromodeoxyuridine and quantified after training on both tasks had ceased. Spontaneous theta activity predicted performance on the first task and the conditioned stimulus induced a theta-band response early in learning the first task. As expected, performance on the first task correlated with performance on the second task. However, theta activity did not increase during training on the second task, even though more cells were present in animals that had learned. Therefore, as long as learning occurs, relatively small changes in the environment are sufficient to increase the number of surviving neurons in the adult hippocampus and they can do so in the absence of an increase in theta activity. In conclusion, these data argue against an upper limit on the number of neurons that can be rescued from death by learning

Enriched Environment Increases PCNA and PARP1 Levels in Octopus vulgaris Central Nervous System: First Evidence of Adult Neurogenesis in Lophotrochozoa

Organisms showing a complex and centralized nervous system, such as teleosts, amphibians, reptiles, birds and mammals, and among invertebrates, crustaceans and insects, can adjust their behavior according to the environmental challenges. Proliferation, differentiation, migration, and axonal and dendritic development of newborn neurons take place in brain areas where structural plasticity, involved in learning, memory, and sensory stimuli integration, occurs. Octopus vulgaris has a complex and centralized nervous system, located between the eyes, with a hierarchical organization. It is considered the most "intelligent" invertebrate for its advanced cognitive capabilities, as learning and memory, and its sophisticated behaviors. The experimental data obtained by immunohistochemistry and western blot assay using proliferating cell nuclear antigen and poli (ADP-ribose) polymerase 1 as marker of cell proliferation and synaptogenesis, respectively, revealed cell proliferation in areas of brain involved in learning, memory, and sensory stimuli integration. Furthermore, we showed how enriched environmental conditions affect adult neurogenesis

Physical skill learning increases neurogenesis through cell survival in the hippocampus

The dentate gyrus is a major site of plasticity in the adult brain, giving rise to thousands of new neurons every day. While the majority of these cells die within two weeks of their birth, they can be rescued from death by various forms of learning. The successful acquisition of select types of associative and spatial memories can increase the number of these cells that survive. Here, we investigated the possibility that an entirely different form of learning, physical skill learning, could rescue these new neurons from death. To test this possibility, rats were trained with a physically-demanding and technically-difficult version of a rotarod procedure. Acquisition of the physical skill greatly increased the number of new hippocampal cells that survived. The number of surviving cells positively correlated with performance on the task. Only animals that successfully learned the task retained the cells that would have otherwise died. Animals that failed to learn, and those that did not learn well, did not retain any more cells than those that were untrained. Importantly, acute voluntary exercise in activity wheels did not increase the number of surviving cells. These data indicate that skill learning, and not physical activity per se, increased the number of surviving cells. Moreover, learning an easier version of the task did not increase cell survival. These data are consistent with previous studies revealing that learning rescues new neurons from death, but only when acquisition is sufficiently difficult to achieve. Finally, complete hippocampal lesions did not disrupt acquisition of this physical skill. Therefore, learning this motor skill task does not depend on the hippocampus, even though it can increase the number of surviving cells in the structure. These data, and their implications, suggest that humans who learn new and complicated sports or other physical skills will retain more new neurons than humans that do not engage in effortful activities.Ph. D.Includes bibliographical referencesby Daniel M. Curlik I

Aktuelle Spannungen und Herausforderungen in der Flüchtlingssozialarbeit aus der Perspektive von ExpertInnen in oberösterreichischen NPOs

Zentrales Thema der vorliegenden Masterarbeit ist die Frage, was die aktuelle Flüchtlingssozialarbeit in Oberösterreich kennzeichnet. Der Fokus liegt dabei einerseits auf die Sekurisierung und Ökonomisierung im Asylbereich und andererseits die Personalstruktur der NPOs. Es wird dabei besonders auf die Zusammenarbeit der Ehrenamtlichen und der Hauptamtlichen Bezug genommen. Dabei werden mögliche Konflikte aufgezeigt und versucht die Ursachen dafür zu analysieren. Ziel ist es, durch eine möglichst umfassende Beschreibung der Ehrenamtlichen auf den besonderen Stellenwert in der Personalstruktur aufmerksam zu machen. Weiters wird die gesellschaftliche Anerkennung für diesen Berufszweig analysiert und diesbezügliche Veränderungen seit der Flüchtlingskrise aufgezeigt. Dazu werden fünf MitarbeiterInnen einzelner NPOs befragt.eingereicht von Anja CurlikUniversität Linz, Masterarbeit, 2017(VLID)196008

Learning increases the survival of newborn neurons provided that learning is difficult to achieve and successful

Processes of learning can increase the survival of new neurons generated in the adult hippocampal formation (Gould et al., 1999; Shors, 2009). However, only some types of learning are effective. Recent studies demonstrate that animals that learn the conditioned response (CR), but require more trials to do so, rescue more new neurons than animals that quickly acquire the CR, or those that fail to acquire the CR. These studies altered task parameters to modify the number of trials required to learn a conditioned response. Here we asked whether pharmacological manipulations that decrease or increase learning would decrease and increase, respectively, the number of cells that remain in the hippocampus after training. To answer this question, we first prevented learning with the competitive NMDA receptor antagonist (±)-3-(2-Carboxypiperazin-4-yl)propyl-1-phosphonic acid (CPP). Administration of the NMDA receptor antagonist CPP each day before training prevented acquisition of the trace eyeblink response, and the subsequent increase in neuronal survival. Second, we facilitated learning with the cognitive enhancer d-cycloserine (DCS), a compound that increases NMDA receptor activity via its actions at the glycine binding site. Administration of the NMDA receptor partial agonist DCS each day before training increased the number of learned responses and the number of cells that survived. Animals that successfully acquired the CR early in training possessed more cells than those exposed to unpaired stimuli but those that learned later in training retained even more newborn neurons. DCS & CPP did not alter performance or cell number when administered after training. These results demonstrate that NMDA receptor activation modifies learning and as a consequence, alters the number of surviving neurons in the hippocampus. Moreover, they demonstrate that associative learning increases neuronal survival provided that the learning is both difficult to achieve and successful .M.S.Includes bibliographical referencesIncludes abstractby Daniel M. Curlik I