Developmental plasticity in aerobic performance in deer mice (Peromyscus maniculatus)

Area of Science:

• Physiology
• Altitude Biology
• Mammalian Physiology

Background:

• Abiotic factors like hypoxia and temperature at high altitudes affect mammalian aerobic performance.
• Limited research exists on how altitude during development influences adult aerobic capacity.

Purpose of the Study:

• To investigate the effects of developmental and adult testing altitudes on basal metabolism and aerobic performance in deer mice.
• To compare aerobic capacity in mice reared and tested at different altitudes, including acclimation strategies.

Main Methods:

• Deer mice were subjected to four developmental and testing regimes: high/low altitude development and testing, low-to-high altitude acclimation, and low-altitude development with acute high-altitude exposure.
• Measurements included basal metabolic rate, aerobic performance, hematocrit, and hemoglobin levels.

Main Results:

• Mice developed and tested at low altitudes exhibited superior aerobic capacity (performance and basal metabolic rate) compared to high-altitude developed or acclimated mice.
• Mice developed at high altitude did not show enhanced aerobic capacity over low-altitude developed and subsequently acclimated mice.
• Mice tested at high altitudes displayed higher hematocrit and hemoglobin levels than those tested at low altitudes.
• Acute hypoxia exposure in acclimated mice did not impair aerobic performance.

Conclusions:

• Developmental altitude plays a crucial role in shaping adult aerobic capacity in deer mice.
• Acclimation to high altitude as adults can partially mitigate the effects of high-altitude development on aerobic performance.
• Physiological adaptations, such as increased red blood cell count, are associated with high-altitude exposure.