Spatial learning as activator of hippocampal neurogenesis during aging and development of Alzheimer\’s disease-like pathology

Poster (download) Alena Burnyasheva1, Tatiana Kozlova2, Ekaterina Rudnitskaya3, Natalia Stefanova41Institute of Cytology and Genetics SB RAS, burnyasheva@bionet.nsc.ru2Institute of Cytology and Genetics SB RAS, kozlova@bionet.nsc.ru3Institute of Cytology and Genetics SB RAS, rudnickaya@bionet.nsc.ru4Institute of Cytology and Genetics SB RAS, stefanovan@bionet.nsc.ru Adult neurogenesis in dentate gyrus (DG) is one of the key mechanisms of neuronal plasticity in hippocampus and plays an important role in cognitive function. However, the consequences of its alteration during healthy aging as well as development of neurodegeneration including Alzheimer’s disease (AD) remain unclear. It was shown that factors which can activate neurogenesis – such as physical exercises and learning – are able to improve cognitive function. Animal models are useful to clarify the connection between adult neurogenesis and cognitive function during development of AD signs, and OXYS rats are a suitable model for the most common sporadic form of AD. Here we examined effects of spatial learning on neurogenesis in DG of OXYS rats prior to and during manifestation of AD signs. We showed altered reference memory of OXYS rats already at the period prior to neurodegeneration. At the period of active manifestation of AD signs OXYS rats demonstrated altered spatial learning and reversal learning, whereas reference memory was altered only a little. At the period of active amyloid-ОІ accumulation in the brain only reference memory of OXYS rats was altered. Spatial learning resulted in accelerated maturation of immature cells of neuronal and astrocytic cell lineages in DG of OXYS and Wistar rats and decrease of amyloid-ОІ content in aged animals.

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Histological evaluation of postnatal retinal development of senescence-accelerated OXYS rats

Poster (download) Darya V. Telegina1, Anna K. Antonenko2, Oyuna S. Kozhevnikova31ICG SB RAS, Novosibirsk, Russia, telegina@bionet.nsc.ru2NSU, Novosibirsk, Russia, antonenko-98@bk.ru3ICG SB RAS, Novosibirsk, Russia, oidopova@bionet.nsc.ru De novo neurogenesis in the adult mammalian retina very limited. Thereby the structural and functional features formed during the period of maturation and formation of retina can have long-term effects on the further ontogenesis of the tissue, however, the mechanisms of these disorders remain unclear. Using model of premature aging OXYS rats we investigatedВ  the early histopathological changesВ  during postnatal retinal neurogenesis. OXYS rats spontaneously develop a retinopathy similar to age-related macular degeneration (AMD). AMD is a complex neurodegenerative disease resulting in a loss of central vision in the elderly. Ganglion, horizontal, and amacrine cells are born in the embryonic phase of rat developmen. Quantitative analysis showed decreasing amacrine cells in OXYS rats as compared Wistar rats (control). At the age of P0 and P1, the number of ganglion and horizontal cells increased in OXYS rats as compared Wistar rats. Bipolar neurons, photoreceptors and MГјller glia are born postnatally. We did not find changes in Muller cells. The number of photoreceptor\’s nuclei per column in Wistar rats increased at the age of P10 and decreased at the age of P14. In OXYS rats, maximum of number of nuclei per column accounted for age of P14 and then decreased. The number of rod bipolar neurons gradually increased by age of P14 in Wistar rats and P10 in OXYS rats. Our results indicating an alteration of retinal formation in OXYS rats during the postnatal period, which may contribute to the early development of their signs of AMD.

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