Abstract
Long-term facilitation (LTF) of Aplysia tail sensory neuron-motor neuron (SN-MN) synapses provides a synaptic correlate of memory for long-term behavioral sensitization of the tail-siphon withdrawal reflex. LTF can be induced by repeated exposures of serotonin (5HT) in the isolated pleural-pedal ganglion preparation. In addition, we have shown previously (Sherff and Carew, 1999) that LTF can also be induced by coincident 5HT exposure comprised of a single 25-min exposure of 5HT at the SN cell body and a 5 min pulse of 5HT at the SN-MN synapses. If synaptic 5HT is applied either 15 min before or after somatic 5HT, LTF is significantly reduced or is not induced at all. These results show that two anatomically remote cellular compartments can functionally interact within a surprisingly short time period. In this chapter, we discuss some of the mechanistic implications of this temporal constraint. We also find that coincident LTF and LTF induced by repeated pulses of 5HT differ (1) in whether they induce another temporal phase of facilitation (intermediate-term facilitation, ITF, expressed up to 1.5 hr after 5HT), and (2) in their requirements for protein synthesis. The results described both in this paper and in the preceding companion paper show 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.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.