Early calcium increase triggers the formation of olfactory long-term memory in honeybees

Emmanuel Perisse, Valérie Raymond-Delpech, Isabelle Néant, Yukihisa Matsumoto, Catherine Leclerc, Marc Moreau, Jean-Christophe Sandoz

Synaptic plasticity associated with an important wave of gene transcription and protein synthesis underlies long-term memory processes. Calcium (Ca2+) plays an important role in a variety of neuronal functions and indirect evidence suggests that it may be involved in synaptic plasticity and in the regulation of gene expression correlated to long-term memory formation. The aim of this study was to determine whether Ca2+ is necessary and sufficient for inducing long-term memory formation. A suitable model to address this question is the Pavlovian appetitive conditioning of the proboscis extension reflex in the honeybee Apis mellifera, in which animals learn to associate an odor with a sucrose reward.