Arctic Ground Squirrel: The Mammal That Loses Memory in Winter, Recovers in Spring

• The Arctic Ground Squirrel (Urocitellus parryii) hibernates for up to 8 months in extreme cold regions like Alaska, Canada, and Siberia.
• During hibernation, its body temperature drops to -2.9°C, heart rate slows to 1-5 bpm, and brain activity becomes almost zero, leading to memory loss.
• Scientists observe that neurons shrink and synapses break during this period, a condition that would cause severe brain damage in humans.
• Every 2-3 weeks, the squirrel briefly 'arouses' to raise its body temperature, a process believed to protect its brain.
• Upon waking in spring, its brain fully recovers, neurons regrow, synapses regenerate, and memory is completely restored, even strengthened.

Why It Matters: The Arctic Ground Squirrel's unique hibernation offers insights into brain protection and memory regeneration.