Duration of the unconditioned stimulus in appetitive conditioning of honeybees differentially impacts learning, long-term memory strength, and the underlying protein synthesis.
This study examines the role of stimulus duration in learning and memory formation of honeybees (Apis mellifera). In classical appetitive conditioning honeybees learn the association between an initially neutral, conditioned stimulus (CS) and the occurrence of a meaningful stimulus, the unconditioned stimulus (US). Thereby the CS becomes a predictor for the US eliciting a conditioned response (CR). Here we study the role of US duration in classical conditioning by examining honeybees conditioned with different US durations. We quantify the CR during acquisition, memory retention, and extinction of the early long-term memory (eLTM), and examine the molecular mechanisms of eLTM by interfering with protein synthesis. We find that the US duration affects neither the probability nor the strength of the CR during acquisition, eLTM retention, and extinction 24 h after conditioning. However, we find that the resistance to extinction 24 h after conditioning is susceptible to protein synthesis inhibition depending on the US duration. We conclude that the US duration does not affect the predictability of the US but modulates the protein synthesis underlying the eLTM's strength. Thus, the US duration differentially impacts learning, eLTM strength, and its underlying protein synthesis.
Freie Universität Berlin, FB Biologie, Chemie, Pharmazie, Institut für Biologie, Neurobiologie, 14195 Berlin, Germany.
Kathrin
K
Marter
Freie Universität Berlin, FB Biologie, Chemie, Pharmazie, Institut für Biologie, Neurobiologie, 14195 Berlin, Germany.
M Katharina
MK
Grauel
Freie Universität Berlin, FB Biologie, Chemie, Pharmazie, Institut für Biologie, Neurobiologie, 14195 Berlin, Germany.
Carmen
C
Lewa
Freie Universität Berlin, FB Biologie, Chemie, Pharmazie, Institut für Biologie, Neurobiologie, 14195 Berlin, Germany.
Laura
L
Morgenstern
Freie Universität Berlin, FB Biologie, Chemie, Pharmazie, Institut für Biologie, Neurobiologie, 14195 Berlin, Germany.
Christina
C
Buckemüller
Freie Universität Berlin, FB Biologie, Chemie, Pharmazie, Institut für Biologie, Neurobiologie, 14195 Berlin, Germany.
Karin
K
Heufelder
Freie Universität Berlin, FB Biologie, Chemie, Pharmazie, Institut für Biologie, Neurobiologie, 14195 Berlin, Germany.
Marion
M
Ganz
Freie Universität Berlin, FB Biologie, Chemie, Pharmazie, Institut für Biologie, Neurobiologie, 14195 Berlin, Germany dorothea.eisenhardt@fu-berlin.de.
Dorothea
D
Eisenhardt
D000818:Animals; D001070:Appetitive Behavior / Q000187:drug effects / Q000502:physiology; D001516:Bees; D001921:Brain / Q000187:drug effects / Q000502:physiology; D003214:Conditioning, Classical / Q000187:drug effects / Q000502:physiology*; D019422:Dietary Sucrose / Q000008:administration & dosage; D004326:Drinking / Q000187:drug effects / Q000502:physiology; D004640:Emetine / Q000494:pharmacology; D005108:Extinction, Psychological / Q000187:drug effects / Q000502:physiology; D057567:Memory, Long-Term / Q000187:drug effects / Q000502:physiology*; D009812:Odorants; D055696:Olfactory Perception / Q000187:drug effects / Q000502:physiology; D010812:Physical Stimulation; D011336:Probability; D014176:Protein Biosynthesis / Q000187:drug effects; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology
D019422:Dietary Sucrose; D011500:Protein Synthesis Inhibitors; D004640:Emetine