Makiguchi Yuya, Abe Takaaki K, Ichimura Masaki
College of Bioresource Sciences, Nihon University, Fujisawa, Kanagawa, Japan.
Shibetsu Salmon Museum, Shibetsu, Japan.
Front Physiol. 2025 May 29;16:1511476. doi: 10.3389/fphys.2025.1511476. eCollection 2025.
This study reanalysed electrocardiogram (ECG) data collected in a previous study on chum salmon to explore sex-specific differences in heart rate variability (HRV) and autonomic nervous system regulation during spawning. The prior research included six female and five male salmon with implanted ECG loggers, observed during spawning, and ten additional females for pharmacological experiments on autonomic nervous system effects. The analysis uncovered distinct HRV patterns between sexes. Females exhibited an increase in heart rate from 82.27 to 86.16 bpm post-spawning, while males decreased from 74.71 to 67.78 bpm. Breakpoint analysis identified four change points in female HRV and five in male HRV. Females displayed a heart rate decrease 21 min before spawning, while males maintained stable rates until spawning. Both sexes experienced cardiac arrest at spawning, consistent with the previous study. HRV changes did not always correspond directly with spawning behaviors, indicating autonomic nervous system involvement beyond physical exertion. Pharmacological experiments showed that atropine, a parasympathetic blocker, suppressed HRV and prevented cardiac arrest, emphasizing the key role of the parasympathetic system in regulating spawning-related HRV. The study suggests that HRV during salmon spawning is regulated by physical activity and autonomic nervous system control, with an important role in parasympathetic activation. This activation begins 20 min before spawning in females, serving as a preparatory mechanism for the physiological demands of spawning. These findings improve our understanding of salmonid reproductive physiology and may inform conservation strategies. Future research should investigate direct measurements of autonomic activity, environmental influences on HRV, and the relationship between HRV patterns and reproductive success. Combining HRV data with other physiological measurements could offer a more comprehensive understanding of the regulatory mechanisms underlying spawning behavior and the energetic costs associated with reproduction in salmonids.
本研究重新分析了在先前一项关于大麻哈鱼的研究中收集的心电图（ECG）数据，以探讨产卵期间心率变异性（HRV）和自主神经系统调节的性别差异。先前的研究包括六只植入了ECG记录仪的雌性大麻哈鱼和五只雄性大麻哈鱼，在产卵期间进行观察，另外还有十只雌性大麻哈鱼用于自主神经系统效应的药理学实验。分析发现两性之间存在明显的HRV模式差异。雌性产卵后心率从82.27次/分钟增加到86.16次/分钟，而雄性则从74.71次/分钟降至67.78次/分钟。断点分析确定雌性HRV有四个变化点，雄性HRV有五个变化点。雌性在产卵前21分钟心率下降，而雄性在产卵前心率保持稳定。两性在产卵时均出现心脏骤停，这与先前的研究一致。HRV变化并不总是与产卵行为直接相关，表明自主神经系统的参与不仅仅局限于体力消耗。药理学实验表明，副交感神经阻滞剂阿托品可抑制HRV并预防心脏骤停，强调了副交感神经系统在调节与产卵相关的HRV中的关键作用。该研究表明，大麻哈鱼产卵期间的HRV受身体活动和自主神经系统控制，副交感神经激活起重要作用。这种激活在雌性产卵前20分钟开始，作为产卵生理需求的一种准备机制。这些发现增进了我们对鲑科鱼类生殖生理学的理解，并可能为保护策略提供参考。未来的研究应调查自主神经活动的直接测量、环境对HRV的影响以及HRV模式与繁殖成功之间的关系。将HRV数据与其他生理测量相结合，可以更全面地了解鲑科鱼类产卵行为的调节机制以及与繁殖相关的能量成本。
