Effects of High-Intensity Interval Training and Moderate-Intensity Continuous Training on Neural Dynamics and Firing in the CA1-MEC Region of Mice.

Abstract

This study is aim to investigate the differential impacts of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on neural circuit dynamics and neuronal firing in the CA1 region and medial entorhinal cortex (MEC) of mice. 42 male ICR mice were randomized into control, HIIT, and MICT groups. Electrophysiological recordings were performed pre- and post-intervention to assess neural circuit dynamics and neuronal firing patterns in the CA1-MEC pathway. Both exercise protocols increased LFP coherence, with MICT showing a more pronounced effect on delta and gamma coherences (P < 0.05). Both modalities reduced delta power spectral density (PSD; HIIT, P < 0.05; MICT, P < 0.01) and elevated theta, beta, and gamma PSDs. Neuronal firing frequency improved in both CA1 and MEC following HIIT and MICT (P < 0.05). HIIT enhanced firing regularity in CA1 (P < 0.05), while MICT improved regularity in both regions (P < 0.05). Both protocols reduced firing latency (HIIT, P < 0.05; MICT, P < 0.01) and enhanced burst firing ratio, inter-burst interval (IBI), burst duration (BD), and LFP phase locking (P < 0.05 or P < 0.01). Notably, MICT significantly improved spatial working memory and novel recognition abilities, as evidenced by increased novel arm time, entries, and preference index (P < 0.01). This study reveals that both HIIT and MICT positively impact neural processing and information integration in the CA1-MEC network of mice. Notably, MICT exhibits a more pronounced impact on neural functional connectivity and cognitive function compared to HIIT. These findings, coupled with the similarities in hippocampal electrophysiological characteristics between rodents and humans, suggest potential exercise-mediated neural plasticity and cognitive benefits in humans.