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Autonomic cardiovascular control in conscious mice
1Institut für Physiologie und Pathophysiologie, Universität Heidelberg, D-69120 Heidelberg, Germany. armin.just@pio1.uni-heidelberg.de
Summary
Mice cardiovascular autonomic control mirrors human patterns but at higher frequencies. Parasympathetic tone primarily drives heart rate variability across all frequencies, with limited reduction above 1 Hz.
Area of Science:
- Cardiovascular Physiology
- Autonomic Nervous System Research
- Comparative Physiology
Background:
- Understanding autonomic cardiovascular control is crucial for studying cardiovascular diseases.
- Mice models offer a valuable tool for investigating autonomic function due to physiological similarities with humans.
Purpose of the Study:
- To characterize autonomic cardiovascular control in conscious mice using spectral analysis.
- To compare mouse autonomic control patterns with those observed in humans.
- To define the roles of parasympathetic and sympathetic nervous systems in heart rate and arterial pressure variability.
Main Methods:
- Spectral analysis of arterial pressure (AP) and heart rate (HR) in conscious, catheterized mice.
- Autonomic blockade using atropine, atenolol, and prazosin.
- Baroreflex modulation of autonomic tone with phenylephrine and nitroprusside.
Main Results:
- Mouse AP and HR spectra resemble human spectra but at higher frequencies.
- Parasympathetic activity, modulated by atropine and nitroprusside, significantly influences HR variability across all frequencies.
- Sympathetic activity, modulated by prazosin and phenylephrine, impacts AP variability primarily at lower frequencies (0.05-3 Hz).
Conclusions:
- Heart rate variability in mice is predominantly controlled by parasympathetic tone at all frequencies.
- Autonomic modulation of cardiovascular function in mice shows distinct frequency-dependent patterns.
- Proposed frequency band limits for mouse cardiovascular autonomic control: 0.15 Hz (VLF/LF) and 1.5 Hz (LF/HF).