Antisense DNA against calcineurin facilitates memory in contextual fear conditioning by lowering the threshold for hippocampal long-term potentiation induction. 2000

S Ikegami, and K Inokuchi
Mitsubishi Kasei Institute of Life Sciences, 11 Minamiooya, Machida-shi, 194-8511, Tokyo, Japan. ikegami@libra.ls.m-kagaku.co.jp

In the previous study, we demonstrated that the antisense oligodeoxynucleotides against calcineurin Aalpha and Abeta, catalytic subunits of Ca(2+)/calmodulin-dependent protein phosphatase, produce a facilitatory effect on long-term potentiation induction in the hippocampal CA1 region in rats anesthetized with urethane. Here, we have studied how animals, in which the hippocampal long-term potentiation induction is enhanced by antisense oligodeoxynucleotides against calcineurin, perform in learning tasks that depend on hippocampal function. The rats received antisense oligodeoxynucleotides by bilateral ventricular administration via miniosmotic pumps. We tested four groups of rats, three infused with either antisense oligodeoxynucleotides, scramble oligodeoxynucleotides, or saline, and untreated rats, for two types of hippocampus-dependent learning, water maze and contextual fear conditioning. After the behavioral tests, we conducted a long-term potentiation induction test to determine whether long-term potentiation induction was enhanced. In contextual fear conditioning, rats in which long-term potentiation induction was enhanced by antisense oligodeoxynucleotides displayed significantly more conditioned freezing response than control rats. Rats with enhanced long-term potentiation induction showed no differences in shock sensitivity, general activity, or light-dark choice from control rats. In contrast with contextual fear conditioning, rats with enhanced long-term potentiation induction showed no difference in spatial learning performance on the water maze compared with control rats. These results demonstrate that an enhancement in long-term potentiation induction produced by the inhibition of calcineurin leads to an increase in memory strength in specific forms of hippocampus-dependent learning.

UI MeSH Term Description Entries
D008297 Male Males
D008568 Memory Complex mental function having four distinct phases: (1) memorizing or learning, (2) retention, (3) recall, and (4) recognition. Clinically, it is usually subdivided into immediate, recent, and remote memory.
D009043 Motor Activity Body movements of a human or an animal as a behavioral phenomenon. Activities, Motor,Activity, Motor,Motor Activities
D003213 Conditioning, Psychological Simple form of learning involving the formation, strengthening, or weakening of an association between a stimulus and a response. Conditioning, Psychology,Psychological Conditioning,Social Learning Theory,Social Learning Theories,Theory, Social Learning
D005239 Fear The affective response to an actual current external danger which subsides with the elimination of the threatening condition. Threat Cues,Threat Sensitivity,Cue, Threat,Fears,Sensitivity, Threat,Threat Cue,Threat Sensitivities
D006624 Hippocampus A curved elevation of GRAY MATTER extending the entire length of the floor of the TEMPORAL HORN of the LATERAL VENTRICLE (see also TEMPORAL LOBE). The hippocampus proper, subiculum, and DENTATE GYRUS constitute the hippocampal formation. Sometimes authors include the ENTORHINAL CORTEX in the hippocampal formation. Ammon Horn,Cornu Ammonis,Hippocampal Formation,Subiculum,Ammon's Horn,Hippocampus Proper,Ammons Horn,Formation, Hippocampal,Formations, Hippocampal,Hippocampal Formations,Hippocampus Propers,Horn, Ammon,Horn, Ammon's,Proper, Hippocampus,Propers, Hippocampus,Subiculums
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D016373 DNA, Antisense DNA that is complementary to the sense strand. (The sense strand has the same sequence as the mRNA transcript. The antisense strand is the template for mRNA synthesis.) Synthetic antisense DNAs are used to hybridize to complementary sequences in target RNAs or DNAs to effect the functioning of specific genes for investigative or therapeutic purposes. Antisense DNA,Anti-Sense DNA,Anti Sense DNA,DNA, Anti-Sense
D017208 Rats, Wistar A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain. Wistar Rat,Rat, Wistar,Wistar Rats
D017774 Long-Term Potentiation A persistent increase in synaptic efficacy, usually induced by appropriate activation of the same synapses. The phenomenological properties of long-term potentiation suggest that it may be a cellular mechanism of learning and memory. Long Term Potentiation,Long-Term Potentiations,Potentiation, Long-Term,Potentiations, Long-Term

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