Taste Memory/Gustatory Neophobia Protocol

General Overview
Mice are transferred from a lab chow diet to a liquid diet of Purina Liquid diet LD101. Following this, mice are maintained at 85-90% of their free-feeding weights by adjusting their daily food ration after weighing. After achieving a consistent baseline of consumption mice are presented with a novel flavored (coffee) liquid diet during the scheduled feeding period. Mice are put back on the non-flavored liquid diet until stable consumption, and re-presented with the coffee. This procedure is repeated one final time for a total of three non-flavored baselines and 3 coffee presentations. The volume of the coffee solution that is consumed in these three presentations represents the degree of taste memory for the solution.

Apparatus
This task is performed in the homecage. Glass bottles with ball bearings in the sipper tube are best to use.

Procedure
This procedure consists of 3 phases intermixed: 1) acclimation, 2) baseline, and 3) testing. Phase 1 is an acclimation period in which the mice are allowed access to only the liquid diet for 72 hours. Every 24 hours mice are given a fresh bottle containing 50 ml of freshly mixed liquid diet. Bottles are weighed at the same time each day to monitor consumption. The purpose of this first phase is to allow mice to acclimate to drinking the liquid diet. Phase 2 consists of a baseline phase in which the mice are fed only the liquid diet 2 times daily: approximately 2 hours in the morning and approximately 1 hour in the late afternoon. Mice are weighed prior to each morning feeding to monitor weight, and feeding times are adjusted accordingly. Following each feeding the bottles are weighed to monitor consumption. Three baseline periods occur throughout testing, the first last 6-9 days and the second and third last 3 days each. The purpose of the first baseline period is to acclimate mice to a twice a day feeding schedule, slowly bring them down to 85-90% of their free feeding weight, and to establish a stable rate of consumption. The purpose of the second and third baseline period is to re-establish a stable consumption rate following the test phase described below. Finally, phase 3 consist of the test phase in which the mice are fed a coffee flavored liquid diet (flavored with Sanka brand decaffeinated instant coffee; 3% by volume) during the 1 hour afternoon feeding; the 2 hour morning feeding remains the same as on baseline days. There are 3 test days through out the experiment and they occur on the days following each of the 3 baseline periods.