F6. CPA alters the feeding behaviour of the pond snail
- M.S.Yeoman, A. W. Pieneman, G. P. Ferguson, A. ter Maat, P. R. Benjamin
- J. Neurophysiol
Materials and Methods The feeding system of the gastropod molluscs has been widely used to study the neural mechanisms of behaviour. One major interest has been control of the central pattern generator (CPG) responsible for generation of the rhythmic movements involved in the consummatory phase of gastropod feeding. One class of neurone involved in controlling the activity of the CPG is the modulatory neurones, so called because they could not initiate rhythmic activity in the CPG but could regulate its output. Classic examples of this type of neurone are the paired serotonergic metacerebral giant cells (MCCs) of , which control the frequency and intensity of the feeding movements but could not drive the basic motor pattern (1). An equivalent pair of serotonergic cells is present in the pond snail, . They are known as the cerebral giant cells and have previously been shown to have a gating function, allowing the animal to respond to food and also to regulate the frequency of feeding movements (2, 3). In this study serotonin concentrations were depleted in the CNS using -chlorophenylalanine ( CPA) and its effects on the feeding behaviour of the animal examined. CPA has been widely used in neurophysiological investigations to diminish serotonin concentrations. It is a competitive inhibitor of the enzyme tryptophan hydroxylase and prevents synthesis of serotonin by stopping production of 5-hydroxytryptophan from tryptophan. Alterations in serotonin concentration were determined using microbore LC with electrochemical detection and standard antibody labelling techniques.