title: Central localization of plasticity involved in appetitive conditioning in Lymnaea.
abstract: Learning to associate a conditioned (CS) and unconditioned stimulus (US) results in changes in the processing of CS information. Here, we address directly the question whether chemical appetitive conditioning of Lymnaea feeding behavior involves changes in the peripheral and/or central processing of the CS by using extracellular recording techniques to monitor neuronal activity at two stages of the sensory processing pathway. Our data show that appetitive conditioning does not affect significantly the overall CS response of afferent nerves connecting chemosensory structures in the lips and tentacles to the central nervous system (CNS). In contrast, neuronal output from the cerebral ganglia, which represent the first central processing stage for chemosensory information, is enhanced significantly in response to the CS after appetitive conditioning. This demonstrates that chemical appetitive conditioning in Lymnaea affects the central, but not the peripheral processing of chemosensory information. It also identifies the cerebral ganglia of Lymnaea as an important site for neuronal plasticity and forms the basis for detailed cellular studies of neuronal plasticity.
authors.affiliation: Sussex Centre for Neuroscience, Department of Biology and Environmental Science, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, United Kingdom. v.straub@sussex.ac.uk
authors.forename: Volko A
authors.initials: VA
authors.lastname: Straub
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Styles
authors.forename: Julie S
authors.initials: JS
authors.lastname: Ireland
authors.forename: Michael
authors.initials: M
authors.lastname: O'Shea
authors.forename: Paul R
authors.initials: PR
authors.lastname: Benjamin
mesh_terms: D000818:Animals; D001070:Appetitive Behavior / Q000502:physiology*; D002490:Central Nervous System / Q000502:physiology*; D002628:Chemoreceptor Cells / Q000502:physiology; D003214:Conditioning, Classical / Q000502:physiology*; D005247:Feeding Behavior / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D009475:Neurons, Afferent / Q000502:physiology; D010465:Perception / Q000502:physiology; D012908:Snails; D013997:Time Factors