Olivia D. Williams / Biology / Faculty Mentor: Jeff Demuth
The loser effect (LE) is the propensity of an organism to lose subsequent resource contests after experiencing an initial loss. Prior work across taxa in memory formation and consolidation suggests that ongoing protein synthesis facilitates both the neural encoding and active recall of losing experiences. In this study, we use the protein synthesis inhibitor cycloheximide (CHX) to test whether ongoing protein synthesis maintains and modulates the intensity of loser effect behaviors in the broad-horned flour beetle, Gnatocerus cornutus. We find that CHX-treated losers took longer to retreat from fights and did not enter LE shutdown as rapidly as untreated beetles; however, CHX-treated losers presented with familiar opponents in a second fight entered LE more quickly than those given a novel opponent. This supports a model in which a) ongoing protein synthesis is required for the typical LE presentation in this beetle and b) LE involves components of both opponent recognition and memory consolidation which may work independently. Further work in which winning beetles are exposed to CHX is required to clarify the role of possible “winner effect”-related behaviors; investigating the molecular mechanisms of LE in this system may also clarify potential genetic influences on stress-related psychopathologies like PTSD.
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