Erschienen:
Springer Science and Business Media LLC, 2009
Erschienen in:BMC Biology
Sprache:
Englisch
DOI:
10.1186/1741-7007-7-30
ISSN:
1741-7007
Entstehung:
Anmerkungen:
Beschreibung:
<jats:title>Abstract</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>Synaptic plasticity associated with an important wave of gene transcription and protein synthesis underlies long-term memory processes. Calcium (Ca<jats:sup>2+</jats:sup>) 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 Ca<jats:sup>2+</jats:sup>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<jats:italic>Apis mellifera,</jats:italic>in which animals learn to associate an odor with a sucrose reward.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>By modulating the intracellular Ca<jats:sup>2+</jats:sup>concentration ([Ca<jats:sup>2+</jats:sup>]i) in the brain, we show that: (i) blocking [Ca<jats:sup>2+</jats:sup>]i increase during multiple-trial conditioning selectively impairs long-term memory performance; (ii) conversely, increasing [Ca<jats:sup>2+</jats:sup>]i during single-trial conditioning triggers long-term memory formation; and finally, (iii) as was the case for long-term memory produced by multiple-trial conditioning, enhancement of long-term memory performance induced by a [Ca<jats:sup>2+</jats:sup>]i increase depends on<jats:italic>de novo</jats:italic>protein synthesis.</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>Altogether our data suggest that during olfactory conditioning Ca<jats:sup>2+</jats:sup>is both a necessary and a sufficient signal for the formation of protein-dependent long-term memory. Ca<jats:sup>2+</jats:sup>therefore appears to act as a switch between short- and long-term storage of learned information.</jats:p></jats:sec>