Meeting Abstract
Sleep is a fundamental and essential component of vertebrate life, although its exact function remains unknown. Animals that are deprived of sleep typically show reduced neurobiological performance, health, and in some cases, survival. However, a number of animals exhibit adaptations that permit them to carry out normal activities even when sleep is restricted or deprived. Lapland longspurs (Calcarius lapponicus), arctic-breeding passerine birds, exhibit around-the-clock activity during their short breeding season, with an inactive period of only 3-4 h/day (71 °N). Whether these birds suffer behavioral and physiological costs associated with sleep loss (SL) is unknown. To assess the effects of SL, wild-caught male longspurs were placed in captivity on long days (16L:8D) and trained for 2 months using a battery of memory tests, including color association, spatial recognition, and color reversal to assess executive function. Birds were then subjected to automated sleep fragmentation cages that interrupt sleep every 2 min (30 arousals/h) for 12 h or control conditions. The criterion for success on each test was marked by completing the operant task correctly within 10 min. After SL (or control) treatment, birds were bled from the alar wing vein to measure plasma corticosterone levels. Preliminary data suggest that SL individuals performed equally, if not better than non-SL individuals, on cognitive tests. These results indicate that this arctic-adapted species may have evolved behavioral and/or physiological adaptations to withstand the costs associated with SL.
