Processos de formação de memória envolvidos na organização da prática

Abstract

The explanations for the positive effects of less repetitive practice in learning, compared to more repetitive practice, converge towards an idea of greater memory strengthening in less repetitive practice. However, there are no studies in the literature that explain, in molecular terms, how the processes of memory formation occur. Thus, the primary objective of the present study was to investigate the association of the glutamate receptors, n-methyl-d-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic (AMPA), with more and less repetitive practice schedules. The secondary objective was to investigate whether the AMPA receptor expression is associated with different memory states, the fast state and the slow state. It was hypothesized that varied practice is more dependent on the NMDA receptor and leads to greater AMPA receptor expression than constant practice. It was also hypothesized that, compared to constant practice, varied practice is more associated with the slow learning and the expression of AMPA receptors. Mice (n = 78) practiced the rotarod in two days of constant (one rotation frequency) or varied (three different rotation frequencies) practice. The animals were tested both 24 hours and 10 days after acquisition. The results indicated that in most of the acquisition trials and on transfer test 2, the animals that received the NMDA receptor blocker in varied practice presented worse performance when compared to the animals that received vehicles in varied practice. The same did not occur in constant practice. In addition, varied practice led to greater expression of the AMPA receptor in relation to constant practice, and this greater expression was associated with the slow state. The findings of the present thesis advance in the explanations of the molecular mechanisms of the greater memory strengthening proposed by the behavioral hypotheses. Furthermore, our results propose an alternative explanation for the explanations formulated at the behavioral level, highlighting the role of the reference of the error produced trial-to-trial.