Overexpression of and RNA interference with the CCAAT enhancer-binding protein on long-term facilitation of Aplysia sensory to motor synapses.
In the marine mollusk Aplysia, the CCAAT/enhancer-binding protein, ApC/EBP, serves as an immediate early gene in the consolidation of long-term facilitation in the synaptic connection between the sensory and motor neurons of the gill-withdrawal reflex. To further examine the role of ApC/EBP as a molecular switch of a stable form of long-term memory, we cloned the full-length coding regions of two alternatively spliced forms, the short and long form of ApC/EBP. Overexpression of each isoform by DNA microinjection resulted in a l6-fold increase in the expression of the coinjected luciferase reporter gene driven by an ERE promoter. In addition, when we overexpressed ApC/EBP in Aplysia sensory neurons, we found that the application of a single pulse of 5-HT that normally induced only short-term facilitation now induced long-term facilitation. Conversely, when we attempted to block the synthesis of native ApC/EBP by microinjecting double-strand RNA or antisense RNA, we blocked long-term facilitation in a sequence-specific manner. These data support the idea that ApC/EBP is both necessary and sufficient to consolidate short-term memory into long-term memory. Furthermore, our results suggest that this double-strand RNA interference provides a powerful tool in the study of the genes functioning in learning and memory in Aplysia by specifically inhibiting both the constitutive and induced expression of the genes.
Lee
J A
JA
National Research Laboratory of Neurobiology, Institute of Molecular Biology and Genetics, School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 151-742, Korea.
Kim
H K
HK
Kim
K H
KH
Han
J H
JH
Lee
Y S
YS
Lim
C S
CS
Chang
D J
DJ
Kubo
T
T
Kaang
B K
BK
D000595:Amino Acid Sequence; D000818:Animals; D001048:Aplysia; D022762:CCAAT-Enhancer-Binding Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D015870:Gene Expression / Q000502:physiology; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D008156:Luciferases / Q000235:genetics; D008568:Memory / Q000502:physiology; D008845:Microinjections; D008969:Molecular Sequence Data; D009046:Motor Neurons / Q000502:physiology*; D009475:Neurons, Afferent / Q000502:physiology*; D012330:RNA, Double-Stranded / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics; D012701:Serotonin / Q000494:pharmacology; D013268:Stimulation, Chemical; D013449:Sulfonamides; D013569:Synapses / Q000502:physiology*; D015533:Transcriptional Activation / Q000502:physiology
D022762:CCAAT-Enhancer-Binding Proteins; D012330:RNA, Double-Stranded; D012333:RNA, Messenger; D013449:Sulfonamides; D012701:Serotonin; C041213:CD 3 color developer; D008156:Luciferases