Convergent mechanisms mediate preparatory states and repetition priming in the feeding network of Aplysia

J Neurosci. 2003 May 15;23(10):4029-33. doi: 10.1523/JNEUROSCI.23-10-04029.2003.


Improvement of behavioral responses to expected stimuli has been attributed to a change in the preparatory state. In this study, we take advantage of the accessibility of the nervous system of Aplysia and develop an in vitro analog of the preparatory state for feeding behaviors. We provide evidence that the change in the preparatory state may be elicited initially by activity of identified serotonergic metacerebral cells (MCCs). We demonstrate, however, that the preparatory state is maintained through MCC-independent repetition priming that is embedded in the properties of the behavior-generating network. Both MCC-dependent and MCC-independent processes converge on the same site in the behavior-generating network to mediate the change in the preparatory state. Thus, we propose a model of how multiple neuronal structures interact to elicit and maintain changes in the preparatory states in the CNS.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Aplysia / physiology*
  • Appetitive Behavior / physiology
  • Contingent Negative Variation / physiology
  • Evoked Potentials, Motor / physiology
  • Evoked Potentials, Somatosensory / physiology
  • Feeding Behavior / physiology*
  • In Vitro Techniques
  • Interneurons / cytology
  • Interneurons / physiology
  • Long-Term Potentiation / physiology
  • Motor Neurons / cytology
  • Motor Neurons / physiology
  • Mouth Mucosa / innervation
  • Mouth Mucosa / physiology
  • Nerve Net / physiology*
  • Patch-Clamp Techniques
  • Presynaptic Terminals / physiology
  • Reaction Time / physiology
  • Reflex, Monosynaptic / physiology
  • Serotonin / physiology
  • Synaptic Transmission / physiology


  • Serotonin