Specific Increase of Hippocampal Delta Oscillations Across Consecutive Treadmill Runs

Abstract

Running speed affects theta (6-10 Hz) oscillations, the most prominent rhythm in the rat hippocampus. Many reports have found a strong positive correlation between locomotion speed and the amplitude and frequency of theta oscillations. However, less is known about how other rhythms such as delta (0.5-4 Hz) and gamma (25-100 Hz) are affected, and how consecutive runs impact oscillatory activity in hippocampal networks. Here, we investigated whether the successive execution of short-term runs modulates local field potentials (LFPs) in the rat hippocampus. To do this, we trained Long-Evans rats to perform voluntary 15-s runs at 30 cm/s on a treadmill placed on the central stem of an eight-shape maze, in which they subsequently performed a spatial alternation task. We bilaterally recorded CA1 LFPs while rats executed at least 35 runs on the treadmillmaze apparatus. Within running periods, we observed progressive increases in delta band power along with decreases in the power of the theta and gamma bands across runs. Concurrently, the inter-hemispheric phase coherence in the delta band significantly increased, while in the theta and gamma bands exhibited no changes. Delta power and inter-hemispheric coherence correlated better with the trial number than with the actual running speed. We observed no significant differences in running speed, head direction, nor in spatial occupancy across runs. Our results thus show that consecutive treadmill runs at the same speed positively modulates the power and coherence of delta oscillations in the rat hippocampus.

Hippocampal delta oscillations entrain neuronal activity, modulate gamma amplitude and convey information about running speed on a treadmill

“…There is, however, provocative new evidence in the literature that associates hippocampal delta oscillations and stationary locomotion. Namely, we recently reported a progressive increase of delta power across consecutive runs at the same speed on a treadmill, which points to rhythmic delta activity as a potential biomarker of running-associated fatigue (Furtunato et al, 2020). Here, we advance this idea by showing that both delta power and frequency increase with increases in stationary running speed on a treadmill (Figures 1 and 2).…”

“…Many reports have corroborated and further highlighted the dichotomy between quiet and ac ve behaviors respec vely exhibi ng delta and theta oscilla ons in the hippocampus (Csicsvari et al, 1998(Csicsvari et al, , 1999Czurkó et al, 1999;O'Neill et al, 2006;Montgomery et al, 2009;Allen et al, 2011;Caixeta et al, 2013;Patel et al, 2013;Schultheiss et al, 2020) . Nevertheless, provoca ve new evidence points to the occurrence of hippocampal delta oscilla ons during sta onary locomo on (Furtunato et al, 2020;Safaryan and Mehta, 2021) , which suggests that the tradi onal dichotomy between theta and delta states may not be clear-cut. Corrobora ng this possibility, here we report an increase in hippocampal delta power and frequency associated with increasing running speed on a treadmill.…”

Pilot study on the evaluation of the effectiveness of psychocorrection methods that include EEG-training and VR headset in athletes involved in extreme kinds of sports

“…Изменение характеристики альфа и дельтаритма в динамике дает возможность рассмотреть процессы, происходящие в головном мозге и связанные с психо эмоциональным напряжением. Однако определение общих критериев абсолютной и относительной спек тральной мощности ритмов ЭЭГ вызывает сложность, так как альфа и дельтаритм в значительной мере харак теризуются индивидуальными особенностями, в связи с чем мы использовали соотношения мощности ритмов ЭЭГ в различных диапазонах [18,19].…”

“…Данные спортсмены не смогли ответить на психокоррекцию ростом мощности в частоте доминирующего альфа ритма. В настоящее время известно, что дельтаритм регистрируется при увеличении активности ЦНС в ус ловиях психоэмоционального напряжения [19]. В связи с этим некоторые авторы рассматривают неокортикаль ный дельтаритм как отражение возбуждения состоя ний ЦНС, а генерализованную ритмическую дельтаак тивность -как свидетельство психоэмоционального напряжения функций коры и подчинения ее активности древним лимбическим системам мозга [19].…”

Genetic Basis of Aerobically Supported Voluntary Exercise: Results from a Selection Experiment with House Mice

“…The hippocampus has been linked to the regulation of speed during locomotor behavior in both mice and rats by theta (Li et al 2012;Fuhrmann et al 2015;Sheremet et al 2019), gamma (Chen et al 2011;Ahmed and Mehta 2012), and delta oscillations (Furtunato et al 2020). Notably, the difference in daily running distance between HR and control lines is attributable mainly to an increase in average (and maximum) running speed, rather than the duration of running, especially in females (e.g., see Garland et al 2011a;Claghorn et al 2016Claghorn et al , 2017Copes et al 2018;Hiramatsu and Garland 2018).…”