Dynamics of Induction and Expression of Long-Term Synaptic Facilitation in Aplysia

@article{Mauelshagen1996DynamicsOI,
  title={Dynamics of Induction and Expression of Long-Term Synaptic Facilitation in Aplysia},
  author={Juliane Mauelshagen and Gerald R. Parker and Thomas J. Carew},
  journal={The Journal of Neuroscience},
  year={1996},
  volume={16},
  pages={7099 - 7108}
}
Serotonin (5HT)-induced short-term facilitation and long-term facilitation (STF and LTF) of the monosynaptic connection between tail sensory neurons (SNs) and motor neurons (MNs) in Aplysiahave been useful in delineating possible cellular mechanisms contributing to short-term and long-term memory. Previous work from our laboratory showed that LTF can be produced in the absence of STF, suggesting that these processes may be functionally independent. In the present study, we explored this… 

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Differential induction of long-term synaptic facilitation by spaced and massed applications of serotonin at sensory neuron synapses of Aplysia californica.
TLDR
Whereas induction of ITF and LTF require similar amounts of 5HT, the cellular mechanisms underlying the induction of LTF are more sensitive to the pattern of the induction trials, suggesting that these two processes may be mechanistically related.
Behavioral, Cellular, and Molecular Analysis of Memory in Aplysia II: Long-Term Facilitation1
TLDR
The results show that two anatomically remote cellular compartments can functionally interact within a surprisingly short time period and that there are multiple forms of both ITF and LTF that differ in their induction and expression requirements, and at least in some instances, the different temporal phases of facilitation, and perhaps comparable phases of memory, can be induced independently of each other.
Parallel somatic and synaptic processing in the induction of intermediate-term and long-term synaptic facilitation in Aplysia.
  • C. M. Sherff, T. Carew
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 2004
TLDR
The findings show that different temporal and spatial patterns of 5-HT induce specific temporal phases of long-lasting facilitation in parallel by engaging different cellular and molecular mechanisms.
Coincident Induction of Long-Term Facilitation at Sensory-Motor Synapses in Aplysia: Presynaptic and Postsynaptic Factors
TLDR
If Aplysia sensory neuron (SN) somata and their remote motor neuron (MN) synapses are simultaneously exposed to serotonin (5HT) pulses, processes activated at these sites interact to induce LTF, which differs mechanistically from coincident LTF.
Behavioral, Cellular, and Molecular Analysis of Memory in Aplysia I: Intermediate-Term Memory1
TLDR
This work has incorporated the temporal and molecular features of these different forms of ITF at tail SN-MN synapses into behavioral analyses, and found that they accurately predict distinct forms of intermediate-term memory for sensitization of the tail-elicited siphon withdrawal reflex.
Persistent Long-Term Facilitation at an Identified Synapse Becomes Labile with Activation of Short-Term Heterosynaptic Plasticity
TLDR
Results indicate that synapses expressing persistent plasticity acquire a “new” baseline and functionally express short-term changes as naive synapses, but the new baseline becomes labile following selective activations—heterosynaptic stimuli that evoke opposite forms of plasticity—such that when presented in the presence of protein synthesis inhibitors produce a rapid reversal of the persistent Plasticity.
Limited contributions of serotonin to long-term hyperexcitability of Aplysia sensory neurons.
TLDR
The induction of LTH by nerve stimulation was enhanced rather than inhibited by treatment with methiothepin, which suggests that endogenous 5-HT may have inhibitory effects on the induction ofLTH by noxious stimulation, whereas later release of 5- HT from persistently activated modulatory neurons, with consequent elevation of cAMP synthesis, may contribute to the maintenance of L TH.
Intermediate-Term Memory for Site-Specific Sensitization in Aplysia Is Maintained by Persistent Activation of Protein Kinase C
TLDR
It is shown that a single tail shock can also induce ITM that is expressed selectively at the trained site (site-specific ITM), which is phenotypically similar to the form of ITM induced by repeated trials, but the mechanisms by which site- specific ITM is induced and maintained are distinct.
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