Author/Editor     Valentinčič, Tine
Title     Behavioral study of chemoreception in the sea star Marthasterias glacialis: structure-activity relationships of lactic acid, amino acids, and acetylcholine
Type     članek
Source     J Comp Physiol (A)
Vol. and No.     Letnik 157
Publication year     1985
Volume     str. 537-45
Language     eng
Abstract     1. Behavioral respnses of Marthasterias glacialis to low molecular compounds were studied under laboratory conditions. Feeding postures, stomach eversions and locomotion of initiality inactive animals can be released with very dilute solutions of lactic acid, neutral 1 amd 3 carbon amino acids, L isomers of 4 to 6 carbon neural amino acids, L-arginine, acetylcholine iodide, and several of their analogues. 2. Hunger was induced by temporary withdrawal of food. Responsiveness to feeding stimuli was controlled with L-cysteine and L-leucine. 3. The lowest behavioral thresholds for the most effective feeding stimuli were 3 x 10-11 mol/l for both enantiomers of lactic acid, 10-8 mol/l for L-proline and both enantiomers of cysteine and 10-7 mol/l for acetylcholine iodine and some of the effective neutral amino acids. 4. The behavioral threshold values for chemical stimuli differed by a factor between 30 and 100 in different sea stars. The test concentration was 3 x 10-7 mol/l, the level at which L -cysteine elicited a complete feeding response from all the animals. Structure-activity comparison of substances less effective that the control stimulus was thus possible. The behavioral threshold of fully effective substances was determined later. 5. The independance of receptor mechanisms for different substances can be inferred as: L-cysteine controlled responsivenesss is not always accompanied by responsiveness to neutral amino acids. Automatized Marthasterias arms crawled after stimulation with lactic acid, cysteine, and acetylcholine iodide but did not respond to the feeding stimuli betaine and L-proline. An animal became inactive if electric shocks were paired with L-proline or L-cysteine emanating from an 'electric' food model. (Abstract truncated at 2000 characters).
Descriptors     BEHAVIOR, ANIMAL
CHEMORECEPTORS
FEEDING BEHAVIOR
MOTOR ACTIVITY
AMINO ACIDS
LACTATES
SENSORY THRESHOLDS
STARFISH
STRUCTURE-ACTIVITY RELATIONSHIP