Mecanismos neuroquímicos envolvidos na modulação da persistência da memória induzida pelo exercício físico agudo

Abstract

The modulation of memory by acute physical exercise (PE) aims to enhance memory consolidation and persistence. It is known that a single session of PE, such as moderate-intensity treadmill running, promotes this effect. The mechanisms involved include the release of neurotransmitters such as noradrenaline and dopamine. However, significant gaps persist regarding the effects and mechanisms of acute PE in memory modulation. The objective of this thesis is to explore how acute PE influences learning and memory persistence. Using adult male Wistar rats as an experimental model, we investigated three essential questions: i) the role of brain regions ventral tegmental area (VTA) and locus coeruleus (LC) in the effects of acute PE on memory; ii) the requirement of hippocampal protein synthesis for acute PE effects on memory persistence; and iii) the impact and mechanisms of acute PE when applied during the late consolidation window, 11 hours after learning. Our results indicate that LC plays a crucial role in the effects of acute PE on memory consolidation and persistence, while VTA does not seem necessary for this process. Furthermore, we found that although hippocampal protein synthesis is vital for memory consolidation, acute PE overcomes inhibition of ribosomal protein synthesis and the mTOR pathway, promoting consolidation but not memory persistence. Moreover, we demonstrated that acute exercise does not elevate the levels of brain-derived neurotrophic factor (BDNF) in the hippocampus during the initial hours following its practice. Lastly, acute PE applied during the late consolidation window was shown to promote memory persistence through activation of beta-adrenergic and dopamine D1/D5 receptors and hippocampal protein synthesis. These findings not only expand our understanding of the mechanisms underlying the effects of acute PE on memory but also provide valuable insights for the development of clinical and therapeutic strategies based on this type of PE, with the potential to enhance memory and learning.