Reward value determines memory consolidation in parasitic wasps

Area of Science:

• Neuroscience
• Animal Behavior
• Insect Physiology

Background:

• Animals form memories, ranging from short-term to consolidated long-term forms.
• Factors influencing natural variations in memory consolidation are not fully understood.

Purpose of the Study:

• To investigate how reward value influences memory consolidation in parasitic wasps.
• To determine if subtle differences in conditioning affect memory mechanisms.

Main Methods:

• Single-trial associative conditioning using high-value and low-value hosts in two parasitic wasp species (Cotesia glomerata and Trichogramma evanescens).
• Assessing memory form consolidation, including protein synthesis dependence and anesthesia sensitivity.

Main Results:

• High-value host conditioning led to protein synthesis-dependent long-term memory (LTM).
• Low-value host conditioning resulted in a shorter-lasting memory form, identified as anesthesia-resistant memory (ARM) in Cotesia glomerata.
• Reward value, not just conditioning intensity, dictates the physiological mechanism of memory consolidation.

Conclusions:

• Memory consolidation is sensitive to subtle differences in reward value.
• Reward-dependent consolidation can exclusively form either ARM or LTM.
• This provides a model for comparing memory consolidation mechanisms within species.