How do mice react to magnetic fields? - briefly
Exposure to static or low‑frequency magnetic fields modifies locomotor activity and triggers stress‑related hormonal responses in laboratory mice. High‑intensity fields can alter neuronal firing patterns and impair spatial navigation.
How do mice react to magnetic fields? - in detail
Mice exhibit measurable changes when exposed to static and time‑varying magnetic fields. Behavioral assays reveal altered locomotor patterns, including reduced exploratory distance and increased thigmotaxis, particularly under fields exceeding 50 µT. Cognitive performance in maze tasks declines proportionally to field strength, with impairments evident at 100 µT and greater.
Physiological recordings show modulation of neuronal firing rates in the hippocampus and somatosensory cortex. Spike‑timing precision decreases, while overall firing frequency may increase or decrease depending on field orientation. Calcium imaging indicates disrupted intracellular Ca²⁺ dynamics, suggesting interference with voltage‑gated channels.
Molecular analyses identify up‑regulation of stress‑responsive genes such as c‑fos and Hsp70 within minutes of exposure. Oxidative stress markers, including malondialdehyde, rise in brain tissue, whereas antioxidant enzymes (superoxide dismutase, catalase) show transient suppression.
Key observations can be grouped as follows:
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Behavioral effects
• Reduced open‑field exploration
• Increased anxiety‑like thigmotaxis
• Impaired spatial learning -
Neurophysiological alterations
• Modified firing rates in hippocampal pyramidal cells
• Disrupted calcium signaling pathways -
Molecular responses
• Immediate‑early gene activation (e.g., c‑fos)
• Elevated oxidative stress markers
Experimental protocols typically employ Helmholtz coils to generate homogeneous fields, with exposure durations ranging from minutes to several hours. Control groups are shielded using mu‑metal enclosures to ensure background geomagnetic conditions. Data acquisition utilizes high‑resolution video tracking, in‑vivo electrophysiology, and quantitative PCR for gene expression profiling.
The underlying mechanism is hypothesized to involve magnetoreceptive proteins, such as cryptochromes, interacting with radical‑pair reactions that influence neuronal signaling. Additionally, induced electric currents at higher frequencies may perturb membrane potentials, contributing to observed effects.
Overall, magnetic field exposure produces consistent, dose‑dependent modifications in mouse behavior, neural activity, and gene expression, providing a robust model for studying magnetobiology and its potential health implications.