The molluscan neuropeptide, SCPB, increases the responsiveness of the feeding motor program of Limax maximus.

Academic Article

Abstract

  • Small cardioactive peptide B (SCPB) has an excitatory effect on both buccal neurons and musculature in numerous molluscan species. The present study reports the effects of SCPB on the activity of specified buccal neurons and the expression of the feeding motor program of the terrestrial slug, Limax maximus. Superfusion of an isolated CNS preparation with 10(-6)M SCPB results in a 3-4-fold increase in the burst frequency of the fast salivary burster neuron (FSB), while having no effect on the activity of another endogenous burster, the bilateral salivary neuron (BSN). The response of the FSB to SCPB is dose dependent, with a threshold concentration of 2 X 10(-8)M. The response of the FSB to SCPB showed no indication of desensitization, even after long-term exposure (20 min). The feeding motor program (FMP) in Limax is a discrete pattern of cyclical motor activity that can be initiated by lip nerve stimulation. In the presence of SCPB a previously subthreshold stimulus can initiate the full FMP. The pattern of the FMP, once initiated, appears unaffected by SCPB. Thus it is the responsiveness of the initiation process that is enhanced by SCPB. Histochemical studies revealed a number of buccal neuron somata and fibers that stain for SCPB-like immunoreactive material (SLIM).
  • Authors

  • Prior, DJ
  • Watson, Winsor
  • Status

    Publication Date

  • January 1988
  • Keywords

  • Action Potentials
  • Animals
  • Central Nervous System
  • Feeding Behavior
  • Immunohistochemistry
  • In Vitro Techniques
  • Mollusca
  • Motor Neurons
  • Neuropeptides
  • Salivary Glands
  • Digital Object Identifier (doi)

    Pubmed Id

  • 3346657
  • Start Page

  • 87
  • End Page

  • 105
  • Volume

  • 19
  • Issue

  • 1