Parallel Molecular Pathways Mediate Expression of Distinct Forms of Intermediate-Term Facilitation at Tail Sensory–Motor Synapses in Aplysia

  title={Parallel Molecular Pathways Mediate Expression of Distinct Forms of Intermediate-Term Facilitation at Tail Sensory–Motor Synapses in Aplysia},
  author={Michael A Sutton and Thomas J. Carew},

Figures from this paper

Activity-dependent inhibitory gating in molecular signaling cascades induces a novel form of intermediate-term synaptic facilitation in Aplysia californica.
Data support the hypothesis that sensory neuron activity coincident with the last RT training trial is sufficient to convert the molecular signaling already established by RT training into an AD-like molecular phenotype.
Behavioral, Cellular, and Molecular Analysis of Memory in Aplysia I: Intermediate-Term Memory1
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.
Coincident Induction of Long-Term Facilitation at Sensory-Motor Synapses in Aplysia: Presynaptic and Postsynaptic Factors
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.
Molecular Mechanisms Underlying a Unique Intermediate Phase of Memory in Aplysia
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
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.
Local synaptic integration of mitogen-activated protein kinase and protein kinase A signaling mediates intermediate-term synaptic facilitation in Aplysia
It is shown that synaptic MAPK activation during TNS is required for the induction of intermediate-term synaptic facilitation, which leads to the persistent synaptic PKA activation required to maintain this facilitation.
Ca2+-Independent Protein Kinase C Apl II Mediates the Serotonin-Induced Facilitation at Depressed AplysiaSensorimotor Synapses
The results demonstrate that short-term facilitation of depressed synapses is mediated by PKC Apl II and suggest that not only different signal transduction pathways but also different isoforms of a specific cascade may mediate physiological responses according to the state of a synapse.
Behavioral, Cellular, and Molecular Analysis of Memory in Aplysia II: Long-Term Facilitation1
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.


Differential induction of long-term synaptic facilitation by spaced and massed applications of serotonin at sensory neuron synapses of Aplysia californica.
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.
Long-term changes in excitability induced by protein kinase C activation in Aplysia sensory neurons.
It is demonstrated that PKC activation can induce both intermediate- and long-term changes in the excitability of sensory neurons (SNs), supporting the idea that memory formation involves multiple stages that are mechanistically distinct at the biochemical level.
Persistent activation of protein kinase C during the development of long-term facilitation in Aplysia.
The results are consistent with the hypothesis that in addition to its role in producing the presynaptic facilitation of mechanosensory-motor neuron synapses that underlie short-term facilitation, PKC is needed for maintaining synaptic changes in an intermediate period that precedes the modifications accompanying consolidation of memory.
Dynamics of Induction and Expression of Long-Term Synaptic Facilitation in Aplysia
The hypothesis that LTF is not a simple elaboration of STF is supported, raising the possibility that STF, ITF, and LTF may reflect components of different memory phases in the intact animal.
Involvement of Presynaptic and Postsynaptic Mechanisms in a Cellular Analog of Classical Conditioning at AplysiaSensory-Motor Neuron Synapses in Isolated Cell Culture
The results suggest that pairing-specific facilitation by serotonin involves Hebbian postsynaptic as well as non-Hebbian presynaptic components that interact in some way, perhaps via retrograde signaling, to specifically enhance evoked, synchronized release of transmitter.
Injection of the cAMP-responsive element into the nucleus of Aplysia sensory neurons blocks long-term facilitation
IN both vertebrates and invertebrates, long-term memory differs from short-term in requiring protein synthesis during training1,2. Studies of the gill and siphon withdrawal reflex in Aplysia indicate
Involvement of protein kinase C in serotonin-induced spike broadening and synaptic facilitation in sensorimotor connections of Aplysia.
The results suggest that the activation of PKC plays a key role in components of both 5-HT-induced spike broadening and facilitation of synaptic transmission.