MSG intake and preference in mice are influenced by prior testing experience

Area of Science:

• Neuroscience
• Sensory Science
• Animal Behavior

Background:

• Monosodium glutamate (MSG) is a common flavor enhancer, providing umami taste.
• While initially not strongly preferred alone, mice develop a preference for MSG with experience.
• Understanding the factors influencing taste preference is crucial for food science and behavior studies.

Purpose of the Study:

• To investigate the conditions that shift mice from indifference to preference for MSG.
• To explore the role of prior experience with various solutions on MSG preference.
• To examine the influence of spout position on taste solution acceptance.

Main Methods:

• C57BL/6J mice underwent two-bottle preference tests with water versus ascending MSG concentrations.
• Mice received forced one-bottle exposure to MSG or other nutritive/sapid solutions before preference tests.
• Preference and intake were measured, and the effect of spout separation was assessed.

Main Results:

• Naive mice were indifferent to MSG, but post-exposure to 300 mM MSG increased preference and intake.
• Experience with nutritive solutions like sucrose and Polycose significantly enhanced MSG preference.
• Spout position influenced preference, with greater separation increasing acceptance.

Conclusions:

• Experience, particularly with MSG and other nutritive substances, significantly enhances umami preference in mice.
• Both oral and post-oral factors likely contribute to the learned preference for MSG.
• Environmental factors like spout placement can modulate taste acceptance in experimental settings.