Selective pressure on a saccharin intake phenotype and its correlates: a replication study

Area of Science:

• Behavioral genetics
• Animal models of human behavior
• Taste and feeding research

Background:

• Selective breeding of High- and Low-Saccharin (HiS and LoS) rats revealed diverse behavioral differences.
• These differences mirrored human gustation, personality, and psychopathology research.
• Original lines were terminated, necessitating replication studies.

Purpose of the Study:

• To test for reproducible, rapid selection of saccharin intake phenotype and correlates.
• To examine the pattern of replication and divergence in replicate lines.
• To investigate the genetic and behavioral underpinnings of taste preferences.

Main Methods:

• Selective breeding of replicate High- and Low-Saccharin (HiS-R and LoS-R) rat lines for 5 generations.
• Assessing intake of various tastants (saccharin, sugars, quinine-adulterated sucrose, NaCl, ethanol) and foods.
• Evaluating non-ingestive behaviors: deprivation-induced hyperactivity, acoustic startle, and open field behavior.

Main Results:

• HiS-R and LoS-R lines diverged significantly in intake of saccharin, disaccharides, quinine-adulterated sucrose, NaCl, and complex foods.
• Open field behavior also showed significant line differences.
• Some observed differences varied from the original HiS and LoS lines.

Conclusions:

• Rapid selection for saccharin intake and associated behaviors is reproducible in replicate rat lines.
• The pattern of replication and divergence provides insights into the genetic architecture of feeding and behavior.
• Further research is needed to understand the reasons for observed differences between original and replicate lines.