Release of peptide cotransmitters from a cholinergic motor neuron under physiological conditions

Elizabeth C. Cropper, David Price, Renata Tenenbaum, Irving Kupfermann, Klaudiusz R. Weiss

Research output: Contribution to journalArticlepeer-review

88 Scopus citations

Abstract

In previous studies, we demonstrated that B15, one of the two cholinergic motor neurons of the accessory radula closer muscle of Aplysia, synthesizes two peptides, small cardioactive peptides A and B (SCPA and SCPB), that, when exogenously applied, increase the size and relaxation rate of muscle contractions elicited by motor neuron stimulation. In the present experiments, we obtained evidence that the SCPs are released under physiological conditions. Specifically, we characterized firing patterns of motor neuron B15 during normal behavior, simulated them in vitro, and demonstrated that this type of neuronal activity produces decreases in SCP levels in neuronal processes and terminals. We also obtained evidence that suggests that enough SCP is released under physiological conditions to modulate neuromuscular activity in the accessory radula closer. We demonstrated that physiological activity of neuron B15 produces significant increases in muscle cAMP levels. Furthermore, increases in the size and relaxation rate of muscle contractions can be produced by changes in stimulation parameters that are also likely to maximize effects of released endogenous SCPA and SCPB.

Original languageEnglish
Pages (from-to)933-937
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Volume87
Issue number3
StatePublished - 1990
Externally publishedYes

Keywords

  • Aplysia
  • Arousal
  • Modulation
  • Muscle contractility
  • Small cardioactive peptide

Fingerprint

Dive into the research topics of 'Release of peptide cotransmitters from a cholinergic motor neuron under physiological conditions'. Together they form a unique fingerprint.

Cite this