Genetically variable taste sensitivity to D-amino acids in mice.

Area of Science:

• Neuroscience
• Genetics
• Sensory Biology

Background:

• D-amino acids are isomers of common amino acids.
• Taste perception involves complex neural pathways and genetic influences.

Purpose of the Study:

• To investigate behavioral and neural responses to various D-amino acids in two inbred mouse strains.
• To determine the genetic basis of taste perception for D-amino acids, particularly D-phenylalanine.

Main Methods:

• Conditioned aversion learning in C57BL and BALB mice using 8 different D-amino acids.
• Generalization testing of conditioned aversions to sucrose.
• Electrophysiological recordings of chorda tympani nerve responses.
• Application of Pronase E, a proteolytic enzyme, to assess taste receptor interactions.

Main Results:

• Aversion to D-valine, D-leucine, D-methionine, D-histidine, and D-tryptophan generalized to sucrose in both strains.
• Aversion to D-alanine and D-serine did not generalize to sucrose.
• Generalization patterns for 7 D-amino acids were similar between strains.
• Aversion to D-phenylalanine generalized to sucrose only in C57BL mice, not BALB mice.
• Pronase E inhibited chorda tympani responses to sucrose and most D-amino acids in both strains.
• Pronase E specifically inhibited D-phenylalanine responses only in C57BL mice.

Conclusions:

• Sweet taste perception shows significant genetic variability, particularly for D-phenylalanine.
• Neural responses to D-amino acids are influenced by genetic background.
• The study identifies D-phenylalanine as a key D-amino acid revealing strain-specific taste responses.