Cocaine decreases saccharin preference without altering sweet taste sensitivity

Area of Science:

• Neuroscience
• Behavioral Science
• Pharmacology

Background:

• Saccharin consumption decreases when paired with cocaine in rodents.
• Previous hypotheses suggest cocaine pairing reduces saccharin's reward value.
• An alternative hypothesis proposes altered taste detection and sensitivity.

Purpose of the Study:

• To investigate if cocaine-saccharin pairing affects sweet taste sensitivity.
• To determine if changes in taste detection or reward devaluation explain suppressed saccharin consumption.

Main Methods:

• Mice taste sensitivity to saccharin was measured before and after cocaine pairing.
• A brief-access lickometer assessed concentration-response curves.
• Measures included EC50, licking avidity, and latency to first lick.

Main Results:

• The EC50 (effective concentration 50%) for saccharin remained unchanged.
• Licking avidity for saccharin, a measure of motivation, significantly decreased.
• Latency to the first lick, indicating motivation, increased significantly.

Conclusions:

• Cocaine-saccharin pairing does not alter saccharin taste sensitivity.
• Findings support the reward devaluation hypothesis, not altered taste detection.
• Cocaine pairing reduces the motivational value of sweet taste rewards.