Neurogenesis of adult mammalian brain is one of the most actively studied phenomena, due to its possible impact on the training and the prospect of use in the treatment of neurodegenerative diseases. Recent studies show that in some cases there are correlations between the processes of neurogenesis and cognitive processes. However, the mechanisms underlying these relationships remain unknown. Present time we can not be considered strictly proved that neurogenesis does play a role in memory and learning. At least, this role is still unclear, although on this occasion there had been some suggestions.
Learning has an impact on the frequency of cell division and survival of new neurons, and the nature of this effect depends on the stage of learning. Those neurons that appeared prior to training, a week after the training is more likely to survive, compared to non-learning animals (Leuner B. et al., 2004; Gould E. et al., 1999). Recent study (Anderson M. et al., 2010) shows that in the formation of memory trace reduced cell survival, appeared shortly before training or at the beginning, but increases survival of cells that have reached the beginning of training weeks of age. Based on this, we hypothesized that during sequential learning effectiveness in the second memory training will decrease compared to the situation when the first training is missing.
The experiment was performed in 17-18-week-old male Wistar rats. Rats were trained in the Morris water maze and T-maze consistently. Before training all rats was injected by bromodeoxyuridine to assess survival of new neurons that appeared before the first training. For the group of rats with a "double training" received significantly lower rates of choosing the right sleeve in T-maze than rats not attending earlier in the Morris maze (p <0.001). Sections of the brain are analyzed to identify communication training with survival of new neurons, proliferation and differentiation of new nerve cells.