title: Effects of age on feeding behavior and chemosensory processing in the pond snail, Lymnaea stagnalis.
abstract: This study used behavioral and electrophysiological techniques to examine age-related changes in the feeding behavior and chemosensory processing in the pond snail, Lymnaea stagnalis. Increasing age was associated with a 50% decrease in long-term food consumption. Analysis of short-term sucrose-evoked feeding bouts showed an age-related increase in the number of animals that failed to respond to the stimulus. Of the animals that did respond increasing age was associated with a decrease in the number of sucrose-evoked bites and a increase in the duration of the swallow phase. These changes were observed with both 0.01 and 0.05M sucrose stimuli but were not seen when 0.1M sucrose was used as the stimulus. Electrophysiological analysis of the chemosensory pathway in semi-intact lip-CNS preparations failed to demonstrate a significant change in the neuronal information entering the cerebral ganglia from the lips via the median lip nerve, but did demonstrate an age-related deficit in the neuronal output from the cerebral ganglia. This deficit was also dependent on the sucrose concentration and mirrored the concentration-dependent changes in feeding behavior. In summary, aging appeared to affect central but not peripheral processing of chemosensory information and suggests that this deficit contributes to the age-related changes in feeding behavior.
authors.affiliation: Physiological Flow Studies Group, School of Bioengineering, Imperial College, Prince Consort Road, London SW7 2AZ, UK.
authors.forename: M
authors.initials: M
authors.lastname: Arundell
authors.forename: B A
authors.initials: BA
authors.lastname: Patel
authors.forename: V
authors.initials: V
authors.lastname: Straub
authors.forename: M C
authors.initials: MC
authors.lastname: Allen
authors.forename: C
authors.initials: C
authors.lastname: Janse
authors.forename: D
authors.initials: D
authors.lastname: O'Hare
authors.forename: K
authors.initials: K
authors.lastname: Parker
authors.forename: P R
authors.initials: PR
authors.lastname: Gard
authors.forename: M S
authors.initials: MS
authors.lastname: Yeoman
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D002628:Chemoreceptor Cells / Q000378:metabolism / Q000502:physiology*; D004435:Eating / Q000502:physiology; D005247:Feeding Behavior / Q000502:physiology*; D008195:Lymnaea / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology; D011499:Protein Processing, Post-Translational